WO2010041059A2

WO2010041059A2 - Vibration management device

Info

Publication number: WO2010041059A2
Application number: PCT/GB2009/051324
Authority: WO
Inventors: Andrew Micklethwaite; Sara Jayne Hildreth; Michael James Jones; Beatrix Joy Dunlop Jones
Original assignee: BECKWITH IP Ltd
Current assignee: BECKWITH IP Ltd
Priority date: 2008-10-07
Filing date: 2009-10-07
Publication date: 2010-04-15
Anticipated expiration: 2011-04-07
Also published as: GB201306524D0; WO2010041059A3; GB201107338D0; GB2476627A; GB2498143A; GB2476627B

Abstract

In a first aspect, a vibration management device comprises a tool sensor couplable to a tool and a vibration monitor couplable to a tool operator. The tool sensor comprises a vibration sensor arranged to generate a vibration signal indicative of the magnitude of vibration of the tool and an RF transmitter arranged to transmit data indicative of the magnitude of tool vibration. The vibration monitor comprises an RF receiver arranged to receive the data indicative of the magnitude of tool vibration and a processor arranged to update a vibration exposure value as a function of the data indicative of the magnitude of tool vibration and the duration of tool vibration. The processor provides a first output signal to an operator if the vibration exposure value exceeds a first exposure threshold. In a second aspect, a vibration management device comprises a mount couplable to a tool and a vibration monitor couplable to the mount. The vibration monitor is arranged to receive tool identification data stored within the mount when the vibration monitor is coupled to the mount. The tool identification data includes a tool vibration magnitude rating. The vibration monitor comprises a vibration sensor arranged to provide a vibration signal indicating whether vibration of the vibration monitor exceeds a first magnitude threshold indicating that the tool is in use. The vibration monitor is arranged to update a vibration exposure value as a function of the tool vibration magnitude rating received from the mount and the duration for which the vibration signal exceeds the first magnitude threshold. The vibration monitor provides a first output signal to an operator if the vibration exposure value exceeds a first exposure threshold. The vibration monitor comprises a first socket and the mount comprises a corresponding second socket arranged such that when the vibration monitor is coupled to the mount the first and second sockets are coupled together such that data may be transmitted between the vibration monitor and the mount.

Description

Vibration Management Device

The invention relates to vibration management devices intended to monitor the exposure of a tool operator to vibration. Embodiments of the invention provide reliable, accurate and inexpensive devices which not only monitor the exposure but also provide a management function by warning the operator when exposure time durations commensurate with relevant Exposure Action Values (EAV) and Exposure Limit Values (ELV) have been reached for a single work shift. Additionally, embodiments of the present invention provide enhanced management functions, for instance for monitoring tool operator working hours, tool usage, tool servicing requirements and long term exposure of operators to vibration.

Current health and safety considerations require that all tool operators who come into contact with machine vibration as part of their daily duties should monitor the duration of that exposure and limit that exposure on a daily basis. Additionally or alternatively it may be a requirement for the exposure to vibration to be monitored and limited over a longer period of time, for instance over a working week incorporating a number of work shifts. Reduced vibration exposure on a first day may allow for greater vibration exposure on a subsequent day or vice versa. A responsibility lies with the employer to facilitate and perhaps oversee that exposure duration management. Various devices have been proposed to achieve that management control.

In this specification reference is made to European Union (EU) regulations and standards, but it will be understood that different regulations and standards may be applicable in different jurisdictions and, if imposed by statute, should be substituted for the regulations and standards discussed herein. In jurisdictions in which there are no mandatory regulations and standards, then those discussed in this specification as being mandatory should be interpreted as representing best health and safety practice.

Prolonged and repeated exposure to mechanical vibration can create in a machine operator the condition of Hand Arm Vibration Syndrome (HAVS) otherwise known as "White Finger". HAVS results from the vibration of the tool being transmitted to the tool operator at the point of contact, usually the operator's hands. The transmitted vibration can cause a range of problems such as bone and joint disorders and damage to nerves in addition to the whitening of the fingers due to a disruption of the blood flow. HAVS has been recognised as typically affecting tool operators operating pneumatic drills or jackhammers, grinders, rivet guns and chipping hammers, amongst others.

HAVS is a function of both the magnitude of the vibration transmitted from the machine and the duration of the exposure to that vibration. Prolonged and repeated exposure to mechanical vibration from machines or tools (hereinafter generally referred to as "tools") can also result in tool operators being exposed to whole-body vibration. Indeed, unless otherwise specifically indicated, reference to vibration affecting a tool operator's finger, hand or arm, or to HAVS should be interpreted generally as referring to tool vibration affecting any part of the tool operator's body.

The human body has a recovery ability and is able to recover from exposure to vibration during a period of rest. Over a typical series of 24-hour cycles it is medically inadvisable regularly to exceed a given duration of exposure to vibration in excess of a given value over each 24-hour period.

EU regulations relating to vibration exposure are defined in ISO 5349/2001 Part 1.

Vibration exposure is calculated as a function of the vibration emitted by the tool and the duration of the exposure to the vibration. ISO 5349/2001 Part 1 is based upon a sampling system whereby the vibration of a tool in a particular configuration for particular use is sampled and the tool assigned a Tool Vibration Magnitude rating (hereinafter TVM rating). ISO 5349/2001 Part 1 requires the calculation of vibration exposure based upon the TVM rating of the tool and the duration of tool use. At the time of defining the standard it was not envisaged that the magnitude of tool vibration could be reliably measured in real time in order to calculate vibration exposure. Reliance upon a rating system results in ISO 5349/2001 Part 1 being a flawed standard as tool vibration can vary significantly in magnitude based upon the tool configuration, the use of the tool and the operator using the tool. ISO 5349/2001 Part 1 places a duty upon an employer to measure, for every machine or tool which is to be used by an employee, a TVM rating Value measured in units of acceleration (m.s^~ ). The measurement of a TVM rating is discussed in greater detail below.

For each working shift, a machine operator will have a defined first vibration exposure threshold which he or she is required not to exceed, and a defined second vibration exposure threshold, somewhat less than the first, above which he or she is expected to monitor carefully the ongoing exposure to vibration as a means of avoiding exposure to vibration above the first threshold. For a tool operator using a single tool during a work shift with a single TVM rating the vibration exposure thresholds equate to a time limit. The time limits vary with the TVM rating, that is the vibration signature of the tool or tools which the operator is using. A single operator using a number of different tools in a single shift (each with its own TVM rating) must observe advisory and limiting time limits of exposure to vibration which are calculated as the root mean square (r.m.s.) of the advisory and limit exposure time durations of each in turn of those different tools.

In the EU, the Control of Vibration at Work Regulations introduced in 2005 require employers to assess the risks from vibration to employees and decide if the levels are likely to exceed a defined daily Exposure Action Value (EAV) or daily Exposure Limit Value (ELV). If the EAV is likely to be exceeded then the employer must take steps to reduce the vibration exposure to as low a level as possible. If above the ELV then the employer must take steps to reduce the vibration exposure to below the ELV.

To enable a tool operator or their employer to monitor cumulative exposure time easily and in a meaningful manner without continual calculation of the root mean square (r.m.s.) of the advisory and limit exposure time durations of each tool used, a so-called points or percentage system has been devised. It is an approximation to compliance with the appropriate health and safety legislation, but it is deemed an acceptable approximation as it provides a conservative approach to calculation of vibration exposure, which is practical to implement in a work environment. Each tool or machine is calibrated not only with its mandatory TVM rating but with a factor to magnify or diminish the impact of that particular tool or machine on an operator's daily advisory and limiting exposure time durations. Therefore if a first machine or tool has a stated TVM rating and a factor of 1, and a second machine or tool with a higher vibration has a higher TVM rating approximately twice that of the first tool, and so a factor of 2, then the operator is able simply to add together the number of hours per shift that they have been exposed to the vibration of the first machine or tool and twice the number of hours per shift that they have been exposed to the vibration of the second machine.

Furthermore, maximum vibration exposure for a tool operator also takes account of the rest or recovery time between shifts by the use of permitted exposure time scales. The (A)8 scale is a table of permitted exposure times for a range of TVM ratings assuming an 8-hour working shift with 16-hour recovery breaks between shifts. The (A 12 scale is more suitable for offshore oil rigs because it assumes a 12-hour shift with 12-hour recovery breaks between shifts. For the (A)8 scale the EAV for hand-arm vibration is a daily exposure of 2.5m. s^"2 (that is, an average exposure to emitted tool vibration of 2.5m. s^"2 averaged over the 8 hour shift). The tool operator's ELV on the (A)8 scale is 5m.s^"2. Exposure values may also be calculated over longer periods of time, for instance through a working week.

Measurement of the TVM rating for each tool or machine is regulated by ISO 5349/2001 Part 1, which stipulates how to test a particular tool or tool configuration for the hand and arm vibration (HAV) that it causes in use. The phrase "tool configuration" indicates that a particular tool may have a number of different test results depending on how it is configured or used. A drill may have different TVM ratings depending on the drill bit used. An angle grinder may have different TVM ratings depending on the cutting wheel used, and whether it is cutting steel, concrete, soft stone or brick. EU legislation requires that TVM ratings are measured for each tool configuration.

The measurement itself is carried out using a multi-axis accelerometer. One such multi- axis accelerometer is a Hand-Arm Vibration Meter Type 2239B manufactured by Bruel and Kjaer of Denmark. The meter must be physically attached to the tool or machine at the precise location where a user can be expected normally to place each of his or her hands to use the tool or machine. Normally that requires two locations. The vibration, measured in m.s^"2, must then be measured over three runs each of two minutes duration. The TVM rating is calculated according to a prescribed formula from the highest vibration output per run, averaged over the three runs. If the different hand locations at which the vibration is tested give different results, then the TVM rating for the tool must be recorded as the higher or highest values measured.

It may be difficult for employers and tool operators to comply with legislation prescribing adherence to usage limits of vibratory equipment on a shift-by-shift basis. If it is left to the tool operator to monitor the amount of time he or she spends using a particular tool, then that monitoring is bound to be inaccurate. Some operators may inadvertently exceed the EAV or ELV daily dosage. Others may either accidentally or even deliberately overestimate their exposure time, so that they may report before the end of their shift that they cannot continue with a particular job because to do so would exceed the permitted limits on exposure to vibration. There have therefore been proposed different apparatuses and devices to monitor and manage the operator's daily exposure to vibration.

GB-2411472 (South West Highways Ltd of the United Kingdom) discloses a vibration monitor to be worn on the wrist of a tool operator. The monitor of GB-2411472 records time, magnitude and frequency information for sensed vibration over a predetermined period of time (typically over a single shift). The monitor samples the vibration magnitude and frequency at a regular rate, for instance once every ten seconds taking a one second sample. The vibration magnitude and frequency information, together with the time of the sample, is stored within the monitor for later retrieval when the monitor is coupled to a computer. This information is then used to generate a spectrograph on the computer, which in turn is used to calculate the exposure of the tool operator to vibration and determine if that exposure exceeds safe limits. Alternatively, the vibration data may be transmitted wirelessly in real time to the computer to monitor the current exposure of the tool operator. There is however no suggestion that the monitor could directly and independently manage a tool operators vibration exposure to provide the tool operator a warning that there is a risk of the EAV or ELV being exceeded. Furthermore, because the vibration measurement is performed upon the operator's wrist, and not upon the tool itself, it is not possible for the vibration monitor to comply with ISO 5349 which mandates measurement of the tool vibration magnitude based upon measurements performed upon the tool.

The vibration monitor of GB-2299169 (British Gas PIc of the United Kingdom) is also intended to be worn on the wrist of a tool operator. A vibration-activated transmitter coupled to each tool sends a radio signal to the monitor whenever that tool is in use. The radio signal identifies the tool to the vibration monitor. When the wrist mounted monitor and the transmitter on each tool are in close proximity it is determined that the operator is using that tool. The vibration monitor on the operator's wrist has its own vibration sensor and is arranged to record the cumulative period for which the vibration exceeds a threshold indicating that the user is using the tool (the actual magnitude of the experienced vibrations are not recorded). The vibration monitor is pre-programmed with information regarding known tool vibration emission data for each tool and so is able to calculate the operator's exposure using the time information for the cumulative duration of tool use. The vibration monitor is able to warn when safe exposure limits are reached by providing an audible or visual alarm. There is no suggestion that the vibration monitor could measure the magnitude of the actual vibration emitted by the tool. Furthermore, there is no suggestion that the vibration monitor could take account of different tool configurations in determining the tool operator's vibration exposure.

WO-2007/072068 (Reactec Ltd of the United Kingdom) discloses a vibration monitor that is attached to a tool rather than to the wrist of a user. The monitor is in two parts: a mount affixed to the tool and a personal monitoring component. The personal monitoring component is detachable from the mount and can be carried by an operator from one tool to another for coupling to the mount for each tool to be used by that operator. A vibration sensor detects vibration of the tool. When vibration is detected, the cumulative vibration exposure of the operator is calculated based upon a known vibration emission rating for the tool. The cumulative vibration exposure is recorded for later analysis when the data is downloaded to a computer. Data download may be performed via a wired or a wireless connection between the personal monitoring component and a base controller coupled to the computer. The calculated cumulative vibration exposure may be compared with the operator's EAV and ELV exposure values and the operator may be advised either to be more cautious over their exposure to vibration or cease that class of work altogether for the day. Typically the personal monitoring component when attached to the machine or tool has three highly visible coloured LED display lights. Green indicates that it is safe to continue to use the machine or tool. Amber indicates that the user must be cautious because the period of exposure to vibration for that particular shift is drawing to an end. Red indicates that the user ought to discontinue using the machine or tool because his/her daily exposure limit has been reached. Additionally, a three digit display may be provided to display the remaining exposure for that operator before they must stop using the tool.

The vibration sensor contained in the vibration monitor of WO-2007/072068 permits the calculation of cumulative vibration exposure, which can be compared with the operators EAV and ELV values. The EAV and ELV data may be pre-recorded on a user ID card, which identifies the user and information relating to the user.

It is an object of embodiments of the present invention to obviate or mitigate one or more of the problems of the prior art, whether identified herein or elsewhere. In particular, it is an object of embodiments of the present invention to provide a vibration management device that both monitors exposure to vibration and provides a warning to the tool operator when daily or weekly vibration exposure limits are approached or exceeded.

According to a first aspect of the present invention there is provided a vibration management device comprising: a tool sensor couplable to a tool, the tool sensor comprising a vibration sensor arranged to generate a vibration signal indicative of the magnitude of vibration of the tool and an RF transmitter arranged to transmit data indicative of the magnitude of tool vibration; and a vibration monitor couplable to a tool operator, the vibration monitor comprising an RF receiver arranged to receive the data indicative of the magnitude of tool vibration and a processor arranged to update a vibration exposure value as a function of the data indicative of the magnitude of tool vibration and a measured duration of tool vibration and to provide a first output signal to an operator if the vibration exposure value exceeds a first exposure threshold. An advantage of the first aspect of the present invention is that because the vibration exposure value is updated as a function of the actual vibration emitted by the tool in real time, changes in tool configuration or use which affect the vibration of the tool are automatically accounted for. Known vibration monitors which are reliant upon the pre- characterisation of a tool cannot reliably provide an indication of the vibration to which the user is exposed because rarely will the actual tool vibration be the same as the tool rating.

The vibration monitor may be arranged to provide a second output signal to an operator if the vibration exposure value exceeds a second exposure threshold. The vibration monitor may comprise three LEDs, and wherein the vibration monitor may be arranged to illuminate a first LED continuously or intermittently if the vibration exposure value is less than the first exposure threshold, to illuminate a second LED continuously or intermittently if the vibration exposure value is greater than or equal to the first exposure threshold and less than the second exposure threshold, and to illuminate a third LED continuously or intermittently if the vibration exposure value is greater than or equal to the second exposure threshold.

The vibration management device may further comprise a programming interface including an RF transceiver arranged to communicate with the vibration monitor thereby connecting the vibration monitor to a computer, the computer including computer program code arranged to transmit at least a first vibration exposure threshold to the vibration monitor and to receive data indicative of the vibration exposure value from the vibration monitor. The vibration monitor may be further arranged to store data indicative of the time and magnitude of the vibration signal and the computer includes computer program code for storing the time and magnitude data in a management information system.

The vibration management device may comprise two or more tool sensors coupled to separate tools, the vibration monitor being arranged to calculate a cumulative vibration exposure value as a function of data indicative of the magnitude of tool vibration received from each tool sensor and a measured duration of tool vibration. The vibration monitor may be arranged to pair with a single tool sensor at any time such that the vibration exposure value is updated only in response to data indicative of the magnitude of tool vibration received from the paired tool sensor. The vibration monitor may be arranged to pair with a single tool sensor if the received data indicative of the magnitude of tool vibration from the tool sensor is above a predetermined signal strength indicating that the vibration monitor and the tool sensor are within a predetermined distance of one another.

The vibration monitor may be arranged to be worn around a wrist of a tool operator. The vibration monitor may further comprise a sensor arranged to detect if the vibration monitor is removed from the tool operator's wrist and to record the time at which the vibration monitor is removed.

The data indicative of the magnitude of tool vibration may further comprise data indicative of the frequency of tool vibration, and the vibration monitor may be further arranged to determine a frequency weighted vibration magnitude value and to use that value to update the vibration exposure value.

According to a second aspect of the present invention there is provided a method of managing the exposure of a tool operator to tool vibration, the method comprising: coupling a tool sensor to a tool, the tool sensor comprising a vibration sensor and an RF transmitter; generating at the vibration sensor a vibration signal indicative of the magnitude of vibration of the tool; transmitting data indicative of the magnitude of tool vibration from the RF transmitter; and coupling a vibration monitor to the tool operator, the vibration monitor comprising an RF receiver and a processor; receiving at the vibration monitor the data indicative of the magnitude of tool vibration from the tool sensor; updating a vibration exposure value as a function of the data indicative of the magnitude of tool vibration and a measured duration of tool vibration; determining if the vibration exposure value exceeds a first exposure threshold; and providing a first output signal to the tool operator if the vibration exposure value exceeds the first exposure threshold. According to a third aspect of the present invention there is provided a vibration management device comprising: a mount couplable to a tool; and a vibration monitor couplable to the mount, the vibration monitor being arranged to receive tool identification data stored within the mount when the vibration monitor is coupled to the mount, the tool identification data including a tool vibration magnitude rating, the vibration monitor comprising a vibration sensor arranged to provide a vibration signal indicating whether vibration of the vibration monitor exceeds a first magnitude threshold indicating that the tool is in use; wherein the vibration monitor is arranged to update a vibration exposure value as a function of the tool vibration magnitude rating received from the mount and the duration for which the vibration signal exceeds the first magnitude threshold and arranged to provide a first output signal to an operator if the vibration exposure value exceeds a first exposure threshold; and wherein the vibration monitor comprises a first socket and the mount may comprise a corresponding second socket arranged such that when the vibration monitor is coupled to the mount the first and second sockets are coupled together such that data may be transmitted between the vibration monitor and the mount.

An advantage of the third aspect of the present invention is that because the tool vibration magnitude rating is stored within the mount coupled to the tool, the vibration monitor may be moved between multiple tools each provided with a separate mount storing a different tool vibration magnitude rating. The vibration monitor automatically takes account in the change of tool vibration emission in updating the vibration exposure value.

The vibration monitor may be arranged to provide a second output signal to an operator if the vibration exposure value exceeds a second exposure threshold.

The vibration monitor may comprise three LEDs, and the vibration monitor may be arranged to illuminate a first LED continuously or intermittently if the vibration exposure value is less than the first exposure threshold, to illuminate a second LED continuously or intermittently if the vibration exposure value is greater than or equal to the first exposure threshold and less than the second exposure threshold, and to illuminate a third LED continuously or intermittently if the vibration exposure value is greater than or equal to the second exposure threshold. The vibration management device may further comprise a programming interface arranged to couple to the vibration monitor and to communicate with the vibration monitor to thereby connect the vibration monitor to a computer, the computer including computer program code arranged to transmit at least a first vibration exposure threshold to the vibration monitor and to receive data indicative of the vibration exposure value from the vibration monitor. The programming interface may be further arranged to couple to the mount and to communicate with the mount to thereby connect the mount to a computer, the computer includes computer program code arranged to transmit the tool vibration magnitude rating to the mount. The vibration monitor may be further arranged to store data indicative of the time of the vibration signal and the computer includes computer program code for storing the vibration time data in a management information system.

The vibration management device may comprise two or more mounts coupled to separate tools, the vibration monitor being arranged to couple to a single mount and to update the vibration exposure value as a function of the tool vibration magnitude rating received from the mount to which the vibration monitor is coupled at that time.

According to a fourth aspect of the present invention there is provided a method of managing the exposure of a tool operator to tool vibration, the method comprising: coupling a mount to a tool, the mount storing tool identification data including a tool vibration magnitude rating; coupling a vibration monitor to the mount, the vibration monitor comprising a vibration sensor to provide a vibration signal; receiving at the vibration monitor from the mount the tool identification data; determining whether the vibration signal exceeds a first magnitude threshold indicating that the tool is in use; updating a vibration exposure value as a function of the tool vibration magnitude rating received from the mount and the duration for which the vibration signal exceeds the first magnitude threshold; and determining if the vibration exposure value exceeds a first exposure threshold; and providing a first output signal to the tool operator if the vibration exposure value exceeds the first exposure threshold; wherein the vibration monitor comprises a first socket and the mount may comprise a corresponding second socket arranged such that when the vibration monitor is coupled to the mount the first and second sockets are coupled together such that data may be transmitted between the vibration monitor and the mount.

In accordance with an embodiment of the invention there is provided a vibration management device for monitoring the exposure of a tool operator or machine operator to vibration, comprising: a mount attachable to or attached to an item which in use experiences vibration that can be transmitted to a tool operator or machine operator, and a detachable monitor which is removably retainable by the mount and which, when removed from the mount, can be linked to a computer to pre-program into the detachable monitor data relating to EAV and ELV data of the tool or machine to be used by the operator, and which, when retained by the mount: senses when the mount is vibrating due to operation of the tool or machine; times the duration of that vibration on a cumulative basis between successive pre-programming operations; displays when the duration of the vibration exceeds that commensurate with the EAV data pre-programmed into the detachable monitor; and displays when the duration of the vibration exceeds that commensurate with the ELV data pre-programmed into the detachable monitor.

Embodiments of the present invention may be arranged to determine the exposure of a tool operator using only a single tool, or using multiple tools, during a work shift. For embodiments of the present invention in which a TVM rating is stored in a vibration monitor or in a mount, a TVM rating for the or each tool available to the operator during a work shift is stored within the monitor. A selection mechanism may be provided to determine which rating is to be used at any time.

The detachable monitor may incorporate a single axis accelerometer to sense when the mount is vibrating due to operation of the tool or machine.

The detachable monitor may incorporate a piezoelectric vibration detector to sense when the mount is vibrating due to operation of the tool or machine.

The detachable monitor may incorporate one or more LEDs to indicate: (a) when the tool or machine has been operated for a total shift duration less than a duration commensurate with the EAV data pre-programmed into the detachable monitor; (b) when the tool or machine has been operated for a total shift duration more than a duration commensurate with the EAV data pre- programmed into the detachable monitor but less than a duration commensurate with the ELV data pre-programmed into the detachable monitor; and (c) when the tool or machine has been operated for a total shift duration more than a duration commensurate with the ELV data pre- programmed into the detachable monitor.

The detachable monitor may be provided with means for calculating, from the data relating to the EAV and ELV data pre-programmed into the detachable monitor, advisory and limiting use duration of the combination of tools or machines during a single working shift. The calculation may be based on the root mean square of the individual durations, during the working shift, that the detachable monitor has sensed mount vibration due to operation of the different tools or machines as identified by the setting of the operator-settable slide or rotary dial. The calculation may be based on a points or percentage factor assigned to each tool or machine and pre-programmed into the detachable monitor along with the data relating to the EAV and ELV data.

The mount may be a moulded rubber sleeve into which the detachable monitor can be removably slid.

The mount may shroud and protect, in use, any socket, terminal or edge connector portion of the detachable monitor which is used to link the detachable monitor to the computer when the detachable monitor is removed from the mount. The detachable monitor may be provided with a USB connector for linking it to a USB port of the computer when the detachable monitor is removed from the mount.

The mount may be provided with an adhesive pad for securing it adhesively to the surface of the machine or tool.

The item to which the mount is attachable or attached may be a glove of an operator, where in use it holds the detachable monitor close to the operator's hands so that the detachable monitor can identify, through the glove, when the tool or machine is operating. The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figures IA, IB and 1C respectively illustrates top, side and bottom views of a detachable monitor in accordance with a first embodiment of the present invention;

Figure 2 is a system diagram showing components of the detachable monitor of figures IA, IB and 1C;

Figures 3A, 3B and 3C respectively illustrates top, side and bottom views of a tool mount arranged to receive the detachable monitor of figures IA, IB and 1C;

Figures 4A and 4B respectively illustrates top and side views of a resect tool arranged to reset the detachable monitor of figures IA, IB and 1C;

Figures 5 A and 5B respectively illustrates top and side views of a programmer arranged to program the detachable monitor of figures IA, IB and 1C and the mount of figures 3 A, 3B and 3C;

Figure 6 is a schematic illustration of a typical computer screen display when the detachable monitor of figures IA, IB and 1C is being pre-programmed using a support computer;

Figure 7 is a schematic illustration of a typical computer screen display when the mount of figures 3A, 3B and 3C is being pre-programmed using a support computer;

Figure 8 is a schematic illustration of a typical computer screen display showing a portion of a management information system containing data downloaded from a vibration monitor according to figure IA; Figure 9 is a vibration monitor in accordance with a second embodiment of the present invention;

Figure 10 is a system diagram showing components of the vibration monitor of figure 9;

Figure 11 illustrates a tool mounted vibration sensor in accordance with the second embodiment of the present invention;

Figure 12 is a system diagram showing components of the tool mounted vibration sensor of figure 11;

Figures 13A and 13B respectively illustrates top and side views of a programmer arranged to program the vibration monitor of figure 9 and the tool mounted vibration sensor of figure 11 ;

Figure 14 is a schematic illustration of a typical computer screen display when the vibration monitor of figure 9 is being pre-programmed using a support computer;

Figure 15 is a schematic illustration of a typical computer screen display when the tool mounted vibration sensor of figure 11 is being pre-programmed using a support computer; and

Figure 16 is a schematic illustration of a typical computer screen display showing a portion of a management information system containing data downloaded from a vibration monitor according to figure 9.

Certain embodiments of the present invention do not measure the magnitude of the vibration when the tool or machine is in use. Rather, the vibration management device senses when there is vibration consistent with operation of the tool or machine. Consequently a simpler accelerometer may be used. All that is needed is a single-axis accelerometer or a piezo-electric vibration detector of the kind contemplated in GB- 2299169. The TVM rating is pre-programmed into the vibration monitor device and this data is preferably obtained prior to use of the vibration management device strictly in accordance with ISO 5349/2001 Part 1 and stored in a table in computer memory against the tool or machine and the specific tool or machine configuration with which the operator will be working on a particular shift.

Further embodiments of the present invention do measure the actual vibration emission from a tool in real time using a vibration sensor mounted upon or integrated within the tool. Advantageously, the vibration sensor and associated electronics may be integrated into a sufficiently small size to be coupled to or within a tool handle such that the measure vibration magnitude is the same as the vibration transmitted to the tool operator. ISO 5349/2001 Part 1 requires the used of predefined TVM ratings as at the time of the definition of the standard it was not considered possible to accurately measure the magnitude of tool vibration in real time. For the reasons discussed above, ISO 5349/2001 Part 1 is flawed in that the TVM ratings assigned to tools take no account of the significant variations in actual tool vibration. This results in a calculated operator vibration exposure which is either too high or too low. Embodiments of the present invention which measure the real time magnitude of tool vibration therefore exceed the requirements of ISO 5349/2001 Part 1.

Data relating to the TVM rating for each tool or tool configuration pre-programmed into a vibration monitor according to the present invention may be either the raw TVM ratings or data derived from raw TVM ratings, such as advisory and limiting usage times based for instance on the (A)8 scale discussed above.

If the tool or machine is used for less than the duration commensurate with the operator Exposure Action Value (EAV) value pre-programmed into a vibration monitor device, then preferably a green LED on the vibration monitor device may be illuminated. If the cumulative duration exceeds that commensurate with the EAV value pre-programmed into the vibration monitor device but is less than that commensurate with a Exposure Limit Value (ELV) value pre-programmed into the vibration monitor device then preferably the green LED is extinguished and an amber LED on the vibration monitor device is illuminated. If the cumulative duration of use of the tool or machine exceeds that commensurate with the ELV value pre-programmed into the vibration monitor device then preferably the amber LED is extinguished and a red LED on the vibration monitor device is illuminated. The operator is thus advised when he ought to be monitoring carefully his continued use of the tool or machine (amber LED illuminated) and when he ought to terminate that use (red LED illuminated).

As a power-saving feature the LEDs may self-extinguish when the detachable monitor senses no vibration, in other words when the accelerometer or piezo-electric vibration detector does not sense vibration consistent with use of the tool or machine.

In certain embodiments of the invention the mount may be attached or attachable directly to the body or housing of the tool or machine, preferably in a highly visible location. The location does not have to be at all related to the tool or machine handles or parts coming into direct contact with the operator, since the vibration monitor device functions only to sense when the tool or machine is in use and is not used to measure vibration for the purpose of calculating EAV and ELV values. For example, on a plate vibrator for tamping down, levelling and compressing a bed of hardcore the mount may be next to the machine motor or vibration plate which receives the maximum amount of vibration, or it may be somewhere on the machine handles. The vibration signatures of those two parts of the machine are massively different, but that difference is immaterial since the vibration monitor device senses and records only when there is vibration consistent with operation of the machine, and does not measure the magnitude of that vibration.

Desirably, the vibration monitor device is configured in such a way that the accelerometer or piezo-electric vibration detector senses a vibration signature of the power tool or machine that is consistent with operation of the power tool or machine. This ensures that vibrations that may arise during transit or idling of the power tool or machine are not sensed and do not contribute to the cumulative timed usage of the power tool or machine.

For a one man/one tool working arrangement, any operator identification that is preprogrammed into the vibration management device also serves as an identification of the tool that is issued to the operator for that working shift. This is a considerable security feature as, at the end of the working shift, all tools and machines ought to be returned to the central store, where it would be the working practice to remove the vibration monitor devices, the contents of which can be read back into the computer to record the data amassed thereon during that working shift. The central computer can then keep control of which operators have returned their tools or machines, and more importantly which operators have failed to return their tools or machines. The possibility of loss from site of hand tools is thus reduced, hi addition, the central computer is able to keep a record of the cumulative hours of use of each tool or machine, which is particularly useful for organising the servicing of the tools or machines at periodic intervals in accordance with the manufacturers recommendations.

Referring now to figures IA to 1C and 2, these illustrate a detachable vibration monitor 100 in accordance with a first embodiment of the present invention.

The detachable vibration monitor comprises a plastic shell 102 which contains and protects the other components. The shell 102 may typically be approximately 50mm long, 8mm wide and 4mm in height. Preferably, the shell 102 is sonic welded to encapsulate the system and provide the internal components with protection against the ambient environment (which in the case of factories and construction sites may be hazardous for electronic components). It will be appreciated that in other embodiments the size and construction of shell 2 may vary. The shell 102 is generally formed as a key fob, including retaining loop 104. The detachable monitor is intended to be transported between tools by a user, and may for instance be attached to the user by a lanyard coupled to the retaining loop 104 to prevent it being misplaced or left attached to the wrong tool (coupled to a tool mount, as described below).

The detachable vibration monitor 100 is powered by an internal battery 106. When the detachable vibration monitor is first supplied, to prevent it being activated before it is required the battery contacts within the shell 102 are separated by a plastic film 108 which extends from the shell 102 and has a pull tab. When the detachable vibration monitor 100 is required for use the plastic film 108 is removed connecting the battery 106 to the processor 110. The action of the plastic film 108 is represented schematically in figure 10 as a switch 112 between the battery 106 and the processor 110. Data stored within the detachable monitor 100 may either be stored within the processor, or there may be separate memory, for instance FLASH memory, provided within the monitor.

The detachable vibration monitor 100 is arranged to be coupled to the mount 114 illustrated in figures 3A to 3C. Specifically, the mount 114 includes a shaped recess portion 116 arranged to receive a curved end of the detachable monitor. The underside of the detachable monitor 100 includes an input socket 118 arranged to couple to a corresponding socket 120 mounted within the recessed portion 116 on the upper surface of the mount 114. The mount 114 may comprise a male socket 120 and the detachable monitor 100 a corresponding female socket 118, or vice versa. Any known socket type may be used. It is preferable that the chosen socket type is resistant to the effects of vibration and dirt. The detachable monitor 100 may be held in place within recess 116 by the action of the coupled sockets. Alternatively, or in addition, the detachable monitor 100 may form an interference fit with the recess 116, or there may be a sprung clip to hold the monitor in position. When the detachable monitor 100 is received in the recessed portion 116 and sockets 118, 120 are coupled together the mount 114 is arranged to provide a signal to the detachable monitor 100 identifying the tool to which the mount 114 is coupled and providing details of the TVM rating for that tool or that particular tool configuration to the processor 110. A data signal identifying the tool, the TVM rating and possibly further information (for instance the remaining battery life of the mount) may be provided when the sockets are first coupled together. Alternatively, this information may be provided by the mount in a continuous cycle.

The mount 114 is arranged to be coupled to a tool by an adhesive or an adhesive pad (not illustrated) on the bottom of the mount. The mount 114 may be a single use application such that it is not necessary to be able to remove the adhesive pad from the tool without damaging the adhesive or the monitor. However, in alternative embodiments of the invention the mount may be transferred to a new tool, and may be reprogrammed through the socket 120, as described below. Preferably the adhesive pad incorporates a layer of foam or a similar compressible material between the monitor and the adhesive such that the monitor may be fixed to curved tool surfaces. Preferably a suitable adhesive is chosen that is capable of bonding to composite, plastic and metal surfaces for a minimum period of three months. The adhesive should be capable of securing the mount 114 throughout the expected temperature range within which the tool may be used (such as in a factory or on a construction site), for instance -2O⁰C to +35°C. Alternatively, the mount 114 may be coupled to a tool using cable ties. The side view of figure 3B shows first and second holes 122 arranged to receive cable ties which pass through the mount and are secured to part of the tool.

Enclosed within the shell 102 of the detachable monitor is a vibration sensor 124. The vibration sensor 124 is arranged to detect vibration of the tool though the mount 114 and pass a vibration signal to the processor 110. The vibration sensor 124 may be a single or a multiple axis accelerometer, or any other sensor capable of detecting vibration. The vibration sensor 124 provides a vibration signal to the processor 110 indicating that the tool is vibrating or providing a value indicative of the magnitude of that vibration. In certain embodiments the processor 110 and the vibration sensor 124 may be a single unit.

The processor 110 is arranged to detect whether the vibration signal from the vibration sensor 124 is greater than a first threshold. The first threshold is indicative of a magnitude of tool vibration indicating that the tool is in normal use. As a precise measurement of the vibration of the tool is not required, a simpler and lower cost vibration sensor may be used, for instance a piezoelectric motion sensor as discussed above. The first threshold indicative of a vibration magnitude representing normal tool usage may be fixed for the detachable vibration monitor. The first threshold may for instance be fixed at 0.5m.s^"2 which is considered to be less than the normal operating vibration magnitude of most machines and tools, but greater than the vibration likely to be encountered during storage and transit. In alternative embodiments, for instance where the detachable vibration monitor 100 is aimed at a particular tool or industry, the first threshold may differ.

The processor 110 is arranged to calculate the cumulative vibration exposure of the tool operator based upon the TVM rating received from the mount 114 and the total time for which the vibration sensor 124 detects that the tool is in use. Given that the processor has exact knowledge of the tool TVM rating calculated accurately in advance, as described in the introductory portion of the present specification, the operator's vibration exposure can be accurately calculated. When the detachable monitor 4 is transferred between tools, the new tool mount may be programmed with a higher tool vibration value. The detachable monitor 100 is arranged to calculate a cumulative value for the tool operator's vibration exposure using any tool according to the calculations techniques discussed above.

The cumulative vibration exposure for the tool operator can be compared with the EAV and ELV values stored in the detachable monitor 100 during the programming of the device. The vibration monitor 100 further comprises three LEDs 126. Alternatively, there may be two LEDs or only a single LED if one or more LED is capable of illuminating in more than one colour. If the cumulative vibration exposure for the tool operator calculated by the processor is less than the EAV value stored in the detachable monitor 100 then a green LED is illuminated or flashes periodically. If the operator's exposure is between the EAV and the ELV then the amber light is illuminated or flashes periodically. If the operator's exposure is above the ELV then the red light is illuminated or flashes periodically. Alternatively, or in addition, there may be further outputs to the tool operator, for instance an LCD display showing, for instance, the remaining duration of tool use for the current tool before the EAV or ELV for the operator will be exceeded, the current vibration exposure for the operator during that shift or the vibration exposure so far for the tool currently in use. Furthermore, an audible alarm or a vibrating alarm may indicate to the user when the EAV or ELV has been exceeded.

Figures IA, IB, 1C, 3A, 3B and 3C (together with certain of the remaining figures discussed below) further illustrate a bar code or serial number 128 and a product logo area 130. The bar codes or serial number 128 may be used for stock management purposes, which may be particularly useful for organisations responsible for large numbers of tools and vibration management devices. The bar code or serial number 128 also allows for manufacturing traceability and for users to keep a record of when tools are serviced and issued, that is allowing users to use the servicing monitor as an administrative tracking device. Refeπing now to figures 4A and 4B there is illustrated a reset tool. The reset tool has a recessed portion 152 arranged to receive a curved end of the detachable vibration monitor 100 in a similar manner to the mount 114. The recessed portion 152 includes a socket 154 arranged to couple to the socket 116 on the underside of the detachable vibration monitor 100. The reset tool 150 further includes first and second LEDs 156, 158. The reset tool further comprises a hole 160 arranged to receive a lanyard or other retaining cord so that it may be carried without risking losing the rest tool. The reset tool may be used to reset a detachable monitor 100. In particular, the reset tool may be used to reset the cumulative vibration exposure value for a tool operator to zero, or to the level at the beginning of a work shift.

The rest tool anticipates a situation in which a vibration monitor 100 is assigned to a tool operator who is then working offsite for a number of days. On the first day the vibration monitor 100 is programmed with the EAV and ELV exposure values for that operator, using the programmer described below in connection with figures 5 A and 5B. During the day the vibration monitor constantly updates a cumulative vibration exposure based upon a TVM rating received from a coupled tool mount 114 and a duration signal derived from the vibration sensor indicating when the tool is in use. The vibration monitor 100 is arranged to store the vibration exposure value and also arranged to store data indicating the time of use of each tool in terms of the associated vibration rating and the duration of use. Normally at the end of a working shift the vibration monitor 100 is returned to the programmer to download the cumulative vibration exposure value and the data indicating the actual vibration experienced. However, if it is not possible to return the vibration monitor to the programmer due to working offset then it is desirable at the start of the next working day to reset the cumulative exposure value. Coupling the vibration monitor 100 to a reset tool 150 allows the cumulative exposure value to be reset to zero to allow a further period of work before the EAV limit is reached. However, the quantitative data regarding actual vibration exposure is not erased. Furthermore, the vibration monitor retains a record of the cumulative exposure value for each day. This data may be downloaded to a support computer when the vibration monitor 100 is returned to a programmer (as described below). Referring now to figures 5 A and 5B there is illustrated a programmer 200 for downloading data to the detachable monitor 100 and the mount 114 and uploading data from the detachable monitor 100. The programmer 200 includes first and second recessed portions 202, 204 arranged to couple to the detachable vibration monitor 100 and the mount 114 respectively. Each recessed portion 202, 204 further comprises a socket 206, 208 arranged to couple to the sockets on the monitor 100 and mount 114 respectively.

The programmer 200 is arranged to couple the vibration monitor 100 and mount 114 to a support computer for programming the EAV and ELV values for the tool operator into the monitor 100 and the TVM ratings into the mount 114. Additionally, the vibration monitor 100 is programmed with data identifying the tool operator to which it is assigned. This information may be useful for tracking patterns of tool usage by particular operators (from the information uploaded to the support computer at the end of a shift identifying the tools used). Tool operator identification information may also help reduce loss and theft of tools as an accurate record is maintained of which tool operators use each tool. Furthermore, tying vibration exposure data to individual tool operators allows a long term record of vibration exposure to be established on the support computer to allow long term trends to be identified and addressed and to provide accurate data in the event of later claim of ill health due to vibration exposure. The programmer 200 couples to the support computer via a USB socket 210 and is powered via a power socket 212. Alternatively, the programmer may be powered only through the USB socket 210. Furthermore, in certain embodiments of the invention the programmer may be arranged to recharge batteries within the detachable monitor 100 and mount 114 through the sockets 206, 208.

Software operates on the support computer for programming the monitor 100 and mount 114. Figures 6 and 7 illustrate first and second screen shots for programming the vibration monitor 100 and mount 114 respectively.

For programming the detachable vibration monitor 100, the screen shot of figure 6 illustrates boxes 220, 222, 224 for the user to enter details of the tool operator's name, ID and site reference. If the tool operator is a known operator and the EAV and ELV monitoring periods are greater than a single working day then the cumulative exposure for that tool operator will be downloaded to the monitor 100. Otherwise, new EAV and ELV values for that tool operator are downloaded to the monitor 100 when the user selects the Program button 226. A report providing information about the selected tool operator's previous vibration exposure can be obtained by selecting the Report button 228 based upon vibration exposure data uploaded from the detachable monitor's at the end of each shift. The upload of data from a detachable monitor at the end of a shift may be triggered automatically upon coupling the monitor 100 to the programmer 200. Additionally, after data is uploaded the memory of the monitor 100 may be automatically cleared. Alternatively, the upload of data and / or clearing of memory may require the support computer operator to select an appropriate control button within the user interface upon the support computer. Selecting the Clear button 230 clears the entered tool operator information.

Similarly, for programming the mount 114, the screen shot of figure 7 illustrates boxes 232, 234, 236 for the user to enter details of the tool name, ID and site reference. The TVM rating, that is the rating for the magnitude of tool vibration emissions may either be automatically retrieved by the support computer and the appropriate check boxes 238 selected if the tool is known to the system, or else the user may manually select or override the vibration level. The tool vibration level is downloaded to the mount 114 when the user selects the Program button 240. A report providing information about the cumulative use of the tool (which may be used to identify when a tool requires servicing) can be obtained by selecting the Report button 240. Tool usage information is obtainable from the data uploaded to the support computer from the detachable monitor at the end of each shift. In addition to updating a cumulative value for the tool operator's vibration exposure, during tool use the vibration monitor stores data identifying the tool used, the duration and time of tool use and any further data retrieved from the mount, for instance an indication of the remaining battery life for the mount. Consequently, the total use of each tool by all tool operators can be monitored. Selecting the Clear button 242 clears the entered tool information.

At the end of a shift each detachable vibration monitor 100 is coupled to a programmer 200 and the operator vibration exposure data is uploaded to the support computer. Specifically, data regarding the length of time the tool operator operated each tool, and the consequent vibration exposure is downloaded to the support PC. This information is used for monitoring the long term exposure of a tool operator to vibration, and is retrievable using the Report button 242 discussed above. Figure 8 illustrates a portion of a management information system displaying data downloaded from a single vibration monitor 100. It will be appreciated that the management information system may alternatively be interrogated to provide information relating to other vibration monitors, information relating to the tools used and information relating to longer term patterns of vibration exposure.

Figure 8 illustrates data downloaded from a single vibration monitor 100 which has been assigned to operator "John Smith" with operator identification number "70648". The site at which the vibration monitor 100 was used is stored; "Leeds". The time and date of issue and return of the vibration monitor (that is, the time and date at which the vibration monitor was originally coupled to the programmer at the beginning of a work shift and when it was returned at the end of the work shift) is recorded. The accumulated use is displayed. The accumulated use is the total duration of any exposure to vibration. The time beyond ELV for which the operator continued working is also displayed. In certain embodiments of the present invention in which the exposure value is updated according to a points or a percentage scale, the accumulated use and the time of use beyond ELV may in fact represent the time of use normalised to a tool having a nominal TVM rating.

There is now described a vibration management device in accordance with a second embodiment of the present invention, hi accordance with the second embodiment, the vibration management device comprises a vibration monitor 300 illustrated in figures 9 and

10 coupled to a tool operator and a tool mounted vibration sensor 320 illustrated in figures

11 and 12. In use, a vibration monitor 300 and a tool sensor 320 are arranged to pair with one another when brought into close proximity so that vibration data and other information may be transmitted wirelessly and securely between the two. The second embodiment of the invention further comprises a programming tool (illustrated in figures 13A and 13B) for downloading data to the vibration monitor 300 and the tool sensor 320 and retrieving stored vibration data from the vibration monitor 300, and a management information system (illustrated in figure 16) for storing and processing vibration data retrieved from the vibration monitor 300. That is, a vibration management system in accordance with the second embodiment of the invention comprises four key components: a vibration monitor, a vibration sensor, a programmer and a management information system.

The pairing process comprises a vibration monitor 300 and a tool sensor 320 which are brought into close proximity, for instance less than Im between them, establishing a wireless communication channel between the two. Vibration management devices in accordance with this embodiment of the invention differ significantly from those described above in that in place of retrieving pre-programmed tool vibration emission data, the tool mounted vibration sensor 320 is arranged to monitor the magnitude of the tool vibration in real time and to pass this information to the operator worn vibration monitor 300 to calculate the users exposure to vibration based upon the actual emitted vibration from each tool. That is, the vibration signal comprises the magnitude of the real time tool vibration and so takes account of changes in tool configuration, changes in the use of the tool and changes in the tool operator, all of which significantly affect the vibration emitted by a tool.

The vibration monitor 300 is arranged to record the vibration magnitude data and to measure the duration of the vibration signal in order to calculate the tool operator's vibration exposure. The vibration monitor 300 may be worn by the tool operator as a wrist watch (as illustrated in figure 9) or on a lanyard around the operators neck, or simply carried in a pocket. The user is not required to take any action when moving from one tool to another, as is the case for the embodiments of the invention described above, in order to ensure that the monitor 300 continues to correctly record vibration exposure.

Consequently, the embodiment of the invention illustrated in connection with figures 9 to 16 comprises an entirely passive system for the tool operator.

The tool sensor 320 is preferably suitably small so as to be able to be attached to a handle of a tool, or such other point as the tool comes into contact with the tool operators body. Consequently the vibration signal transmitted to the vibration monitor 300 accurately reflects the vibration to which the tool operator is exposed. Therefore, while differing in approach to the vibration exposure monitoring defined by ISO 5349, the vibration management device of figures 9 to 16 exceeds those requirements and represents an improved way of accurately calculating a tool operator's vibration exposure.

Furthermore, the embodiment of the present invention illustrated in figures 9 to 16 may be considered to be a total tool and operator management device given that it provides functionality far in excess of vibration management. For instance, the management device may additionally be used to monitor the use of particular tools by a group of tool operators to identify when a tool requires servicing. Furthermore, the management device allows the working hours and working practices of individual tool operators to be monitored and controlled. Further advantageous features are described in greater detail below.

Figure 9 and 10 illustrates a vibration monitor 300 in accordance with the further embodiment of the present invention. The vibration monitor 300 is preferably in the form of a wristwatch so that it may be worn by a tool operator. However, the vibration monitor 300 may be arranged to be worn by the operator or secured to the operator in any other way providing that the manner in which it is worn ensures that it comes into close proximity to the tool mounted vibration sensor allowing the two to successfully pair with one another, hi order for a vibration monitor 300 and a tool sensor 320 to become paired, they may have to be brought into close proximity with one another, for instance within Im. Proximity may be measured by measuring the received signal strength from the tool sensor at the vibration monitor, and / or vice versa. Once activated (that is, after initially being coupled to a tool or a machine, the tool sensor 320may be arranged to periodically transmit a beacon. Each vibration monitor 300 may be arranged to receive the beacon signals and if it is determined that a tool sensor is in sufficiently close proximity to transmit a return signal to the tool sensor 320. Upon receipt of the return signal the tool sensor 320 may be arranged to continuously or periodically transmit a vibration signal indicative of the current magnitude of the tool vibration, together with identification data or other information, as described below. When the vibration monitor identifies that the signal received from the tool sensor is no longer within sufficiently close proximity it may be deduced that the tool operator is no longer using that tool. The vibration monitor 300 illustrated in figure 9 comprises a central portion 302 including a LCD display 304 for displaying the current time to the tool operator and a strap 306 with a buckle 308. The vibration monitor 300 includes a timing circuit (not shown, or integrated with the processor 312) to calculate the duration of tool usage (based upon the time for which a vibration magnitude signal is received from a paired tool sensor 320 which exceeds a first threshold indicating that the tool is in use). The duration of tool usage in combination with the vibration magnitude is used to calculate the tool operators vibration exposure. Additionally the timing circuit provides a time signal for display 304. The timing circuit preferably is arranged to adjust for different time zones as well as for daylight saving time. For instance, the current time signal may be set based upon a Radio Frequency (RF) time signal such is broadcast in the United Kingdom and other countries, or the time may be adjusted during programming of the vibration monitor 300. The programming of vibration monitors is described in greater detail below in connection with figures 14 and 15.

A vibration monitor in the form of a wristwatch may be provided with a sensor (not illustrated) to detect when the monitor is removed by a tool operator. For instance, the sensor may be integrated into the central portion 302 so as to be in contact with the tool operators arm. The sensor may comprise a temperature sensor and / or a skin conductivity sensor arranged to provide a signal indicating whether the vibration monitor is being worn on the tool operator's wrist. If the sensor detects that the vibration monitor 300 has been put on or removed the event is stored within the monitor with the time at which it occurs and may be later downloaded when the vibration exposure data is retrieved from the vibration monitor at the end of a shift. Data stored by the vibration monitor 300 may either be stored within internal processor memory or a separate memory device, such as a RAM chip, may be provided. Detecting whether a vibration monitor has been removed reduces the possibility of abuse of the vibration management device. In particular, this information may be used to determine whether the correct tool operator has been continuously wearing the vibration monitor all day and so whether the vibration exposure data accurately reflects which tools the operator has used. The knowledge that this data is monitored may reduce the incidence of tool operators using tools which they are not qualified to use, voluntarily exceeding their ELV or overestimating their tool usage for a shift. The central portion 302 further comprises three LEDs 310, one green, one amber and one red. The LEDs are arranged to indicate to the tool operator whether the cumulative vibration exposure calculated for the operator during the current shift or monitoring period exceeds the EAV or ELV values stored in the vibration monitor. The use of the LEDs 310 to display this information is generally the same as for the detachable monitors described above. Alternatively, or in addition, the vibration monitor 300 may provide an audible signal or a vibration signal to an operator if the EAV or ELV for that user has been exceeded. The display 304 may also be used to display information relating to the cumulative exposure, current vibration exposure or the predicted duration of tool use remaining before an EAV or an ELV limit is exceeded. Furthermore, the LEDs may indicate when a vibration monitor 300 has been paired with a tool mounted vibration sensor 320. For instance, the LEDs may not be illuminated unless the vibration monitor 300 is paired with a vibration sensor 320.

The pairing process is now described. The wireless communication between the vibration monitor 300 and the vibration sensor 320 may use and suitable short to medium range wireless communication protocol. For instance wireless communication transceivers arranged to operate in accordance with the IEEE 802.15.4 (2.4Ghz) physical layer standard may be used. A proprietary software protocol operating over the IEEE 802.15.4 data channel is used to transmit and receive data between the vibration monitor and the tool sensor. For additional security IEEE 802.15.4 utilises 128-bit AES (Advanced Encryption Standard) to encrypt communications between tool sensors and vibration monitors. Specifically, the tool sensor is arranged to transmit the start and stop times of tool vibration, the magnitude of the tool vibration (which may be either a precise measurement of the tool vibration or a determination of a vibration band corresponding to the current vibration), tool information, for instance identifying the tool, and the sensor battery level indicated by hours run count. Advantageously, approximating the vibration magnitude into one of a number of bands (for instance 10) significantly reduces the amount of data transmitted, while still providing for much more accurate vibration exposure monitoring as changes in tool use and configuration are automatically reflected in a changing vibration band. When a tool sensor detects that vibration has begun the sensor begins to transmit a signal to all vibration monitors within ranged providing a pin number identifying the tool sensor. Each vibration monitor that receives the tool sensor pin number returns their own pin number, which may for instance be a unique 40-bit serial number, together with the Received Signal Strength Indication (RSSI) of the signal received from the tool sensor (that is, an indication of the signal strength). The tool sensor determines from the received vibration monitor signals which vibration monitor is closest to the tool sensor (indicating which tool operator is using the tool).

The tool sensor then transmits the above described information indicating the start of a period of vibration (start time, the magnitude of the tool vibration, tool information and the sensor battery level) together with the pin for the closest vibration monitor. Each vibration monitor receiving the start information checks to see whether the broadcast pin matches its own pin. If so, the start information is stored and used to update the vibration exposure value and to provide a record of tool usage.

When the tool sensor determines that vibration of the tool has stopped (that is, the magnitude of tool vibration falls below a threshold value), the tool sensors transmits stop information (stop time, the magnitude of the tool vibration, tool information and the sensor battery level) together with the pin of the previously determined closest vibration monitor. Each vibration monitor receiving the stop information checks if the pin matches its internally stored pin, and if so stores the stop information and updates the vibration exposure value according to the vibration magnitude and the time elapsed since the start time. The tool sensor then clears the vibration monitor pin and the process begins again.

The construction of the central portion 302 may be from similar materials and performed using similar techniques to the detachable vibration monitors described above. Alternative construction techniques and materials known for wrist watches will be well known to the appropriately skilled person. The central portion 302 encloses a processor 312 powered by a battery 314. The vibration monitor is typically a consumable device. The casing of the monitor is preferably water, dust and shock proof. Preferably, the battery 314 has a life span of at least 12 months.

The processor 312 is arranged to receive a vibration signal from the tool vibration sensor 320 through a communications circuit 316, for instance a Radio Frequency (RF) transceiver. The processor 312 is arranged to calculate the tool operator's cumulative exposure to vibration as a function of the magnitude of the vibration (using the vibration signal received via the communications circuit 316) and the duration of the vibration. The calculation of the cumulative vibration exposure is generally the same as the calculations described above, though typically will be based upon the absolute vibration exposure determined through the r.m.s. of the exposure from each individual tool. Typically the vibration exposure is calculated on the basis of a periodic sample of the tool vibration magnitude. For instance, the magnitude may be sampled once every ten seconds. The tool sensor 320 may be arranged to perform this sampling and periodically transmit a vibration magnitude value to the vibration monitor 300. Alternatively, the tool sensor 320 may transmit a continuous or semi-continuous vibration magnitude signal and the sampling may be performed by processor 312 within the vibration monitor 300. If the sampled vibration magnitude value exceeds a first threshold indicative of tool use (to prevent vibration during storage or transit of tools contributing to the exposure calculation of a paired vibration sensor) then the cumulative vibration exposure value is updated as a function of the sampled vibration magnitude and the time since the preceding sample.

The processor 312 is arranged to store the following data during use, for later analysis when the data is uploaded to a support computer at the end of each shift: which specific tool an operator has used, the tool data programmed into the respective tool mounted vibration sensor 320, the time and duration of tool usage, the vibration exposure at each time of usage, the total vibration exposure and the remaining battery life for each tool mounted vibration sensor 320 with which the vibration monitor 300 has been paired. Data relating the tool and the vibration of the tool is received from the tool mounted vibration sensor 320 and is described in greater detail below. During programming of the vibration monitor 300 (described in greater detail below in connection with figure 14) the vibration monitor may be programmed with the current operator's name, payroll number and NI number. Furthermore, each vibration monitor 300 has a unique serial number that is incorporated into its memory (either integrated with the processor 312 or a separate component). The vibration monitor 300 may be customised with each operator's name and payroll number. This is particularly desirable if each tool operator is assigned a personal vibration monitor 300, which would typically be the case if the vibration management device is intended to monitor cumulative vibration exposure over a monitoring period longer than a single shift.

Figures 11 and 12 illustrate the tool mounted vibration sensor 320. The tool sensor 320 may be manufactured in a similar fashion to the detachable vibration monitors and mounts described above, and may be similarly coupled to a tool using adhesives or cable ties. Alternatively, the tool sensor 320 may be integrated within a tool such that it is not susceptible to damage. As a further alternative, a plastic moulded holster shaped to receive the tool sensor 320 may be permanently fixed to the tool, for instance using glue. The tool sensor 320 may then the releasably coupled to the holster such that it can be removed and replaced as required, for instance in the event of battery failure or other malfunction of the tool sensor. The tool sensor 320 incorporates a vibration sensor 322, a processor 324 for processing a vibration signal received from the vibration sensor 322, a power supply 326 and a communications circuit 328, for instance an RF transceiver. The processor is arranged to control the transceiver 328 to transmit the vibration signal to the vibration monitor 300, as will be described in greater detail below.

The transmitted vibration data between the tool vibration sensor 320 and the vibration monitor 300 may be encrypted to ensure that sensitive data is not available to third parties. Additionally, the encrypted communication between a paired vibration sensor and a tool sensor prevents other vibration sensors receiving the vibration magnitude signal and incorrectly updating their vibration exposure value. A tool sensor may only pair with a single vibration monitor. However, in accordance with certain embodiments of the present invention a vibration monitor may pair with more than one tool vibration sensor. For instance, for tools which require two handed operation there may be tool vibration sensor on each handle and the tool operator's vibration exposure value may be updated as a function of the tool sensor experiencing the greater vibration. Alternatively, the vibration monitor may be arranged to pair with a similar vibration sensor coupled to another part of the operator's body, for instance and ankle, in order to separately monitor whole body vibration. This may be desirable when the tool operator is using a vibrating tool in an environment which is itself vibrating, for instance on board a ship. Further embodiments of the present invention may also be arranged to wirelessly communicate with, and pair with, other forms of sensor, for instance a noise sensor, and to monitor and record for later analysis the information the other sensors provide.

During the handshake process to establish a pairing between a vibration monitor 300 and a tool sensor 320, the tool mounted vibration sensor 320 transmits the following information to the vibration monitor: tool details such as an identification number, vibration levels measured during usage, vibration levels based on pre-programmed expected levels and remaining sensor battery life.

The tool mounted vibration sensor 320 further comprises two LEDs 330 or a single LED capable of illuminating in more than one colour. When in use a green LED indicates that the vibration sensor 322 has both detected vibration and has paired successfully with a vibration monitor 300. A red LED indicates that the processor 324 has detected that the battery 326 is nearing the end of its life. Either the battery must be replaced or the whole tool sensor 320 replaced. Battery life may also be monitored remotely by a supervisor operating the support computer if data regarding the predicted remaining battery life for a tool mounted vibration sensor 320 is transmitted to a vibration monitor 300 and then later uploaded to the support computer. Typically, the battery is chosen to provide a 6 month life span, for a normal intensity pattern of tool usage. For tool vibration sensors 320 which are integrated into the body or casing of a tool, the power supply may be derived directly from the tool and so no further battery or LED is required. The body of the tool may include a window allowing the green LED to be viewed, or the LED may be positioned outside of the tool. The vibration sensor 322 may be a single or a multiple axis accelerometer, or any other sensor capable of detecting vibration. The vibration sensor 322 measures the magnitude of the tool vibration. In certain embodiments the processor 324 and the vibration sensor 322 may be a single unit.

The vibration sensor 322 may be a 3-axis accelerometer capable of performing vibration sensing in accordance with the internationally recognised performance standards for measuring the TVM rating, as discussed in the introductory portion of this specification. The magnitude of the sensed vibration is then determined in the processor 324 from the vibration signal received from the vibration sensor 333. The vibration magnitude is then transmitted to the operator worn vibration monitor 300 via the communications circuit 328. The vibration magnitude may be sampled periodically and transmitted continuously to the vibration monitor 300. Alternatively, the vibration magnitude may be monitored during each session of tool usage and transmitted to the vibration monitor 300 to update the cumulative vibration exposure value for that tool operator at the end of the work session.

In embodiments of the present invention, the data transmitted to the vibration monitor 300 may be indicative only of the magnitude of the vibration. However, in embodiments of the present invention the vibration magnitude data may be frequency weighted such that vibration at certain frequencies contributes more to the total vibration magnitude value. For instance, the low and high frequency vibrations may effectively be ignored when calculating the vibration magnitude. The result of the frequency weighting is a single vibration magnitude value expressed in units of acceleration (m.s^~2). The frequency weighting may be performed by processor 324 within the tool sensor 320. Alternatively, it in certain embodiments, data indicating magnitude and frequency of vibration is transmitted to the vibration monitor 300 and the conversion to a single vibration magnitude value is performed at processor 312 in the vibration monitor 300. Regardless of the location at which the conversion is performed, the end result is a single vibration magnitude value, which may be according to the standard A(8) or A(12) scale discussed above. Once the conversion to a vibration magnitude value is performed the vibration frequency information is lost. That is, the vibration monitor 300 stores only the cumulative vibration exposure value (and optionally data relating to the vibration magnitude over time) and the frequency of the vibration is not later recoverable from the stored data.

According to one embodiment of the present invention, the determination of a frequency weighted vibration magnitude value is as follows. The vibration sensor 322 within the tool sensor 320 comprises a three-axis vibration sensor arranged to measure the magnitude, frequency and duration of vibration along three orthogonal axes. For each session of vibration the magnitude, frequency and duration data for the three axes is transmitted wirelessly to the vibration monitor 300. A session is defined as one continuous period of tool use. The data may be transmitted continuously during the session or only at the end of the session. In practice, there may be multiple short duration sessions during a working day. For instance, a session for a power drill may be the length of time taken to drill a single hole before the drill is temporarily switched off. At the same time the tool sensor may also transmit pre-programmed identification data, for instance a sensor serial number, a tool serial number, tool make, tool type and tool owner.

The operator worn vibration monitor 300 is arranged to receive the transmitted vibration magnitude, frequency and duration data and to calculate for each session a vibration exposure value. The vibration exposure value (or dose) is used to update a cumulative exposure value, and may also be separately stored. The dosage calculation is performed in accordance with British Standard BS EN ISO 5349-1 2001. Specifically, the vibration dosage calculation is a frequency weighted r.m.s. (root mean squared) average of each of the x, y and z values. The vibration monitor accumulates these vibration "dosages" and warns operatives of if a daily EAV (exposure action value) of 2.5m/s2 A(8) or an ELV (exposure limit value) of 5 m/s2 A(8) has been reached.

The A(8) values and calculations are in accordance with The Control of Vibration at Work Regulations 2005 which implement European Council Directive 2002/44/EC (OJ No L 177, 6.7.2002, p.13) on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (vibration)(sixteenth individual Directive within the meaning of Article 16(1) of Directive 89/39 I/EEC). Alternatively, in place of measuring the current vibration level, the tool mounted vibration sensor may be pre-programmed with a TVM rating or indicative value using the points or percentage system. The tool sensor may be programmed with the tool's rated vibration output available from the manufacturer or from an independent database such as OPERC. The TVM ratings may be separately determined using specialist equipment of the sort discussed in the introductory portion of this specification. When the processor 324 detects that the tool is in use (by detecting that the magnitude of the vibration signal from the vibration sensor 322 exceeds a threshold) then the TVM rating may be transmitted to the operator vibration monitor 300 in place of a value indicative of the actual vibration magnitude. The user's vibration exposure may then calculated by the vibration monitor on the basis of the standard tool vibration data and the cumulative duration of use. If a system user has chosen to use a tool rating value rather than allowing the vibration management system to measure vibration, the calculations to determine the A(8) vibration exposure dosage will utilise that vibration rating rather than a measured vibration magnitude value.

Before first use the tool mounted vibration sensor 320 is programmed with the following data: tool serial number, tool model, tool description, tool manufacturer, tool owner and sensor serial number. Some or all of this data may be transmitted via the communications circuit 328 to the operator vibration monitor 300, along with the vibration magnitude data. This information may then be stored by the vibration monitor 300 for later use in tracking tool usage and the tools used by individual operators.

Referring now to figures 13A and 13B there is illustrated a programmer 350 for the vibration monitor 300 and the tool vibration sensor 320. The programmer 350 includes first and second recessed portions 352, 354 arranged to receive the vibration monitor 300 and the tool vibration sensor 320 respectively. The programmer 350 is equipped with a communications circuit (not illustrated) arranged to wirelessly communicate with the vibration monitor 300 and the tool vibration sensor 320 in order to exchange data to program the vibration monitor 300 and the tool vibration sensor 320 and to upload tool operator vibration exposure data and tool usage data from the vibration monitor 300. Consequently, it may not be necessary for the vibration monitor 300 and the tool sensor 320 to be brought into physical contact with the programmer 350 in order for data to be transferred. Specifically, the programmer 350 transmits identification data, EAV, ELV and TVM ratings, where required, to the vibration monitor 300 and the tool vibration sensor 320. The data transmitted is discussed in greater detail below in connection with figures 14 and 15.

The programmer 350 couples to the support computer via a USB socket 356, which may also provide electrical power to the programmer 350 or there may be a separate power supply socket (not shown). The programmer 350 also allows data to be uploaded on a daily or weekly basis via the software interface from the vibration monitor 300, as described below.

Where vibration monitors 300 are assigned to individual tool operators, the programmer 350 may be used as a clocking in / clocking off device. At the start and end of each shift a vibration monitor 300 is returned to the programmer 350 and positioned on the programmer 350 so that data may be uploaded or downloaded. The time at which this happens is stored and may be used to calculated the hours when a tool operator is at work. At the end of each shift the time at which the vibration monitor 300 is returned to the programmer 350 is recorded by the support computer. Furthermore, as noted above, the time at which the vibration monitor 300 is removed by a user is stored and may be later uploaded to the support computer. This information may be used to determine if there is an interruption in work during a shift. Certain embodiments of the present invention may integrate a GPS receiver within the vibration monitor in order to record where the tool operator is during a work shift. Alternatively, other location tracking systems, for instance based upon GSM or other mobile communication protocols may be used to track the location of tool operators.

The software operating on the support computer for programming the vibration monitor 300 and the tool vibration sensor 320 is generally similar to the software described above in connection with figures 14 and 15. Figures 14 and 15 illustrate first and second screen shots for programming the vibration monitor 300 and the tool vibration sensor 320 respectively. For programming the vibration monitor 300, the screen shot of figure 14 illustrates boxes 400, 402, 404 for the user to enter details of the tool operators name, E) and site reference. If the tool operator is a known operator and the EAV and ELV monitoring periods are greater than a single working day then the cumulative exposure for that tool operator will be downloaded to the monitor 300. The EAV and ELV monitoring period may be switched between daily and weekly using check boxes 412. Otherwise, new EAV and ELV values for that tool operator are downloaded to the monitor when the user selects the Program button 406. A report providing information about the selected tool operator's previous vibration exposure can be obtained by selecting the Report button 408. Selecting the Clear button 410 clears the entered tool operator information.

Similarly, for programming the tool vibration sensor 320, the screen shot of figure 15 illustrates boxes 420, 422, 424 for the user to enter details of the tool name, ID and site reference. The tool vibration emission value may either be automatically selected from check boxes 238 if the tool is known to the system, or else the user may manually select or override the vibration level. That is, as an alternative to the tool vibration sensor 320 measuring the real time magnitude of tool vibration and transmitting that data to the vibration monitor 300, a predetermined vibration magnitude corresponding to the tool's TVM rating may be transmitted to the vibration mom^'tor when the vibration sensor detects that the vibration is above a minimum threshold indicating that the tool is in use. When a tool vibration sensor 320 is to transmit the real time tool vibration magnitude to the vibration monitor 300 this is set by selecting the check box labelled "Automatic". The tool vibration level is downloaded to the tool vibration sensor 320 when the user selects the Program button 428. A report providing information about the cumulative use of the tool (which may be used to identify when a tool requires servicing) can be obtained by selecting the Report button 430. Selecting the Clear button 432 clears the entered tool information.

At the end of a shift each vibration monitor 300 is coupled to a programmer 350 and the operator vibration exposure data is downloaded. Specifically, data regarding the length of time the tool operator operated each tool, and the consequent vibration exposure is downloaded to the support computer. This information is used for monitoring the long term exposure of a tool operator to vibration, and is retrievable using the Report button 430 discussed above. Data may be uploaded to the support computer automatically in response to the vibration monitor being brought into close proximity to the programmer. Alternatively, this may require the support computer user to manually trigger the upload of data. This vibration data identifies the tool operator, the tool or tools used, the vibration magnitude during that use of the tool and the duration of tool use. The report function of the software running on the support computer allows the cumulative exposure of tool operators over extended periods of time to be logged, monitored and assessed to identify whether there may be long terms risks to the tool operators health. The duration of tool use data may also be used to monitoring the cumulative usage of a particular tool, and identifying when that indicates that the tool requires servicing.

The data uploaded from the vibration monitors 300 at the end of each shift also allows the supervisor to identify which users used which tools for tool usage tracking purposes, and in particular which user was the last to use each tool, which may be beneficial in reducing the incidence of theft of tools. The data uploaded includes for each operator, the times at which a vibration monitor is put on or taken off, the time when each tool is used, tool master data (serial number, make, model, owner), the vibration generated by the tool on each occasion of usage, the operator's daily and weekly cumulative vibration exposure, the time and date at which the EAV and ELV values were reached and if operator worked beyond those times.

Data uploaded from the vibration monitor's may be stored within the support computer in a management information system. For each operator the management information system may be used to track which specific tool was used, the date and time of use, the operators vibration exposure, whether the EAV and ELV levels were reached and whether the operator worked beyond the ELV limit. This information may be particularly useful for identifying tool operator's who are at risk of long term health problems from vibration exposure so that the risk can be minimised, for instance by a change in working practices. Additional data may also be stored within the management information system, for instance if a written warning is issued to a tool operator in response to the tool operator exceeding the ELV limit and data indicating which tools an operator is qualified to use, and if they use other tools.

Vibration monitors may be individually assigned to tool operators for extended periods of time, for instance upwards of a year. For employers operating multiple sites each tool operator may be required to present their personal vibration monitor upon appearing for work at a work site. The programmers and support computers at each work site may be networked to allow operator vibration exposure data to be retrieved at each site and data uploaded from each vibration monitor to be uploaded to a centrally controlled management information system to allow tool operators to work at any site while their vibration exposure is monitored in a consistent manner.

Where embodiments of the present invention refer to triggering output signals in the event of a vibration exposure value exceeding an EAV or ELV value, it will be understood that alternatively other vibration exposure thresholds may instead be set.

For each tool the management information system may be used to track which operators have used the tool, the time and date the tool was used and who was the last logged operator to have contact with the tool. This information may be stored over a period of many years to be later accessed and interrogated. The management information system may also be used to generate alerts at the support computer allowing a supervisor to readily identify which operators have reached and\or exceeded EAVVELV values and which vibration monitors and tool mounted vibration sensors are getting to the end of their battery life.

Figure 16 illustrates a portion of a management information system displaying data downloaded from a single vibration monitor 300. It will be appreciated that the management information system may alternatively be interrogated to provide information relating to other vibration monitors, information relating to the tools used and information relating to longer term patterns of vibration exposure. The data extracted from the management information system is presented in the form of a spreadsheet, however it will be appreciated that the data may be stored, processed and presented in other ways. Figure 16 illustrates data downloaded from a single vibration monitor 300 which has been assigned to operator "John Smith" with operator identification number "70648". The site at which the vibration monitor 300 was used is stored; "Leeds". The time and date of issue and return of the vibration monitor (that is, the time and date at which the vibration monitor was originally coupled to the programmer at the beginning of a work shift and when it was returned at the end of the work shift) is recorded.

The screenshot of figure 16 further displays whether the ELV vibration exposure limit is calculated for that user on a daily or weekly basis, whether the ELV was reached and the duration of use beyond the ELV. Furthermore, the vibration exposure is recorded by splitting the actual vibration magnitude determined by the vibration sensor into 10 levels and indicating the total duration of tool use at each level.

Finally, figure 16 presents a record of the time at which the vibration monitor handshaked with each tool, which provides a record of which operators used each tool. The management information system may also be used to determine cumulative tool usage for each tool based upon data retrieved from the vibration monitors assigned to each tool operator.

The management information system is an integral part of a vibration management system in accordance with the second embodiment of the invention. The management information system provides the ability to control the use of the vibration monitors and vibration sensors. Data relating to the use of tools and the exposure of operators to vibration may be proactively managed in order to identify long terms trends, incidences of overexposure or excessive tool use and to provide a permanent record of events in case the information is required in the future. Furthermore, the data may be used to monitor working hours.

Vibration management devices in accordance with various embodiments of the present invention have been described above. It will be understood that the appropriate vibration management device chosen will depend upon the application, including the type of tool, the type of industry, and other factors, for instance the cost of each alternative type of device.

It will be readily apparent to the skilled person that there is significant commonality between the various vibration management devices described above, and so where features are described in connection with one embodiment of the present invention it will be readily apparent that those features may be applied to the remaining embodiments of the present invention.

Further applications of, and modifications to, embodiments of the present invention will be readily apparent to the appropriately skilled person without departing from the scope of the appended claims.

Claims

CLAIMS:

1. A vibration management device comprising: a tool sensor couplable to a tool, the tool sensor comprising a vibration sensor arranged to generate a vibration signal indicative of the magnitude of vibration of the tool and an RF transmitter arranged to transmit data indicative of the magnitude of tool vibration; and a vibration monitor couplable to a tool operator, the vibration monitor comprising an RF receiver arranged to receive the data indicative of the magnitude of tool vibration and a processor arranged to update a vibration exposure value as a function of the data indicative of the magnitude of tool vibration and the duration of tool vibration and to provide a first output signal to an operator if the vibration exposure value exceeds a first exposure threshold.

2. A vibration management device according to claim 1 , wherein the vibration monitor is arranged to provide a second output signal to an operator if the vibration exposure value exceeds a second exposure threshold.

3. A vibration management device according to claim 2, wherein the vibration monitor comprises three LEDs, and wherein the vibration monitor is arranged to illuminate a first LED continuously or intermittently if the vibration exposure value is less than the first exposure threshold, to illuminate a second LED continuously or intermittently if the vibration exposure value is greater than or equal to the first exposure threshold and less than the second exposure threshold, and to illuminate a third LED continuously or intermittently if the vibration exposure value is greater than or equal to the second exposure threshold.

4. A vibration management device according to any one of the preceding claims, further comprising a programming interface including an RF transceiver arranged to communicate with the vibration monitor thereby connecting the vibration monitor to a computer, the computer including computer program code arranged to transmit at least a first vibration exposure threshold to the vibration monitor and to receive data indicative of the vibration exposure value from the vibration monitor.

5. A vibration management device according to claim 4, wherein the vibration monitor is further arranged to store data indicative of the time and magnitude of the data indicative of the magnitude of tool vibration and the computer includes computer program code for storing the time and magnitude data in a management information system.

6. A vibration management device according to any preceding claim, comprising two or more tool sensors coupled to separate tools, the vibration monitor being arranged to calculate a cumulative vibration exposure value as a function of data indicative of the magnitude of tool vibration received from each tool sensor and the duration of tool vibration received from each tool sensor.

7. A vibration management device according to claim 6, wherein the vibration monitor is arranged to pair with a single tool sensor at any time such that the vibration exposure value is updated only in response to data indicative of the magnitude of tool vibration received from the paired tool sensor.

8. A vibration management device according to claim 7, wherein the vibration monitor is arranged to pair with a single tool sensor if the received data indicative of the magnitude of tool vibration from the tool sensor is above a predetermined signal strength indicating that the vibration monitor and the tool sensor are within a predetermined distance of one another.

9. A vibration management device according to any one of the preceding claims, wherein the vibration monitor is arranged to be worn around a wrist of a tool operator.

10. A vibration management device according to claim 9, wherein the vibration monitor further comprises a sensor arranged to detect if the vibration monitor is removed from the tool operator's wrist and to record the time at which the vibration monitor is removed.

11. A vibration management device according to any one of the preceding claims, wherein the data indicative of the magnitude of tool vibration further comprises data indicative of the frequency of tool vibration, and the vibration monitor is further arranged to determine a frequency weighted vibration magnitude value and to use that value to update the vibration exposure value.

12. A method of managing the exposure of a tool operator to tool vibration, the method comprising: coupling a tool sensor to a tool, the tool sensor comprising a vibration sensor and an RF transmitter; generating at the vibration sensor a vibration signal indicative of the magnitude of vibration of the tool; transmitting data indicative of the magnitude of tool vibration from the RF transmitter; coupling a vibration monitor to the tool operator, the vibration monitor comprising an RF receiver and a processor; receiving at the vibration monitor data indicative of the magnitude of tool vibration from the tool sensor; updating a vibration exposure value as a function of the data indicative of the magnitude of tool vibration and a measured duration of tool vibration; determining if the vibration exposure value exceeds a first exposure threshold; and providing a first output signal to the tool operator if the vibration exposure value exceeds the first exposure threshold.

13. A vibration management device comprising: a mount couplable to a tool; and a vibration monitor couplable to the mount, the vibration monitor being arranged to receive tool identification data stored within the mount when the vibration monitor is coupled to the mount, the tool identification data including a tool vibration magnitude rating, the vibration monitor comprising a vibration sensor arranged to provide a vibration signal indicating whether vibration of the vibration monitor exceeds a first magnitude threshold indicating that the tool is in use; wherein the vibration monitor is arranged to update a vibration exposure value as a function of the tool vibration magnitude rating received from the mount and the duration for which the vibration signal exceeds the first magnitude threshold and arranged to provide a first output signal to an operator if the vibration exposure value exceeds a first exposure threshold; and wherein the vibration monitor comprises a first socket and the mount comprises a corresponding second socket arranged such that when the vibration monitor is coupled to the mount the first and second sockets are coupled together such that data may be transmitted between the vibration monitor and the mount.

14. A vibration management device according to claim 13, wherein the vibration monitor is arranged to provide a second output signal to an operator if the vibration exposure value exceeds a second exposure threshold.

15. A vibration management device according to claim 14, wherein the vibration monitor comprises three LEDs, and wherein the vibration monitor is arranged to illuminate a first LED continuously or intermittently if the vibration exposure value is less than the first exposure threshold, to illuminate a second LED continuously or intermittently if the vibration exposure value is greater than or equal to the first exposure threshold and less than the second exposure threshold, and to illuminate a third LED continuously or intermittently if the vibration exposure value is greater than or equal to the second exposure threshold.

16. A vibration management device according to any one of claims 13 to 15, further comprising a programming interface arranged to couple to the vibration monitor and to communicate with the vibration monitor to thereby connect the vibration monitor to a computer, the computer including computer program code arranged to transmit at least a first vibration exposure threshold to the vibration monitor and to receive data indicative of the vibration exposure value from the vibration monitor.

17. A vibration management device according to claim 16, wherein the programming interface is further arranged to couple to the mount and to communicate with the mount to thereby connect the mount to a computer, the computer includes computer program code arranged to transmit the tool vibration magnitude rating to the mount.

18. A vibration management device according to claim 16 or claim 17, wherein the vibration monitor is further arranged to store data indicative of the time of the vibration signal and the computer includes computer program code for storing the vibration time data in a management information system.

19. A vibration management device according to any one of claims 13 to 18, comprising two or more mounts coupled to separate tools, the vibration monitor being arranged to couple to a single mount and to update the vibration exposure value as a function of the tool vibration magnitude rating received from the mount to which the vibration monitor is coupled at that time.

20. A method of managing the exposure of a tool operator to tool vibration, the method comprising: coupling a mount to a tool, the mount storing tool identification data including a tool vibration magnitude rating; coupling a vibration monitor to the mount, the vibration monitor comprising a vibration sensor to provide a vibration signal; receiving at the vibration monitor from the mount the tool identification data; determining whether the vibration signal exceeds a first magnitude threshold indicating that the tool is in use; updating a vibration exposure value as a function of the tool vibration magnitude rating received from the mount and the duration for which the vibration signal exceeds the first magnitude threshold; and determining if the vibration exposure value exceeds a first exposure threshold; and providing a first output signal to the tool operator if the vibration exposure value exceeds the first exposure threshold; wherein the vibration monitor comprises a first socket and the mount comprises a corresponding second socket arranged such that when the vibration monitor is coupled to the mount the first and second sockets are coupled together such that data may be transmitted between the vibration monitor and the mount.