JPS59500029A - Temperature compensated displacement display switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Temperature compensated displacement display switch Technical field The present invention generally relates to temperature compensated displacement indicating switches.

More specifically, it relates to switches useful for monitoring pressure differentials across fluid filters. This switch is designed to handle high pressure differentials and fluid flow caused by clogged filters. It has the ability to distinguish between high pressure differences caused by temperature-induced viscosity. There is.

Background technology Many fluid systems have one or more fluid lines in the fluid line to remove fluid-borne contaminants. A typical example that uses more filters is a forced circulation lubrication system.

Increasing amounts of contaminants are trapped in these filters and passed through the fluid lines. The fluid flow gradually decreases.

For this reason, periodic replacement of the filter element is necessary. The flow rate through the filter is at a specific level. If the filter is not replaced when the temperature drops below the This may result in damage and improper operation.

Devices have been developed to warn when the pressure across the filter exceeds a predetermined amount.

Such devices typically include monitoring the fluid pressure differential from the inlet to the outlet of the filter. Includes sensors that When this pressure difference reaches a certain level, the sensor activates. Activates the filter clogging warning device.

For many fluids, especially lubricating oils, the fluid viscosity at low temperatures is high even with good filters. Even if the fluid pressure difference exceeds the initial warning value even under conditions that are considered to be favorable, It is of sufficient size. To deal with this, many displacement display warning devices are It incorporates a type of temperature-activated compensating element that prevents the warning device from operating at this low temperature. It's twisted. It seems like this, the fluid temperature exceeds the temperature limit value and the fluid pressure difference exceeds the pressure limit The warning device operates only when the value exceeds 1 (1).

Current temperature-compensated fluid pressure differential warning devices incorporate electrical temperature-activated compensation elements. They are classified into two types: those that incorporate a mechanical temperature-operated compensation element, and those that incorporate a mechanical temperature-operated compensation element. . In the former case, the pressure sensor responds by sensing a differential pressure of at least a predetermined magnitude. 1-7 A switch that moves from one of the open and closed states to the other is usually included in the warning device. Ru.

Warning devices typically operate in response to changes in this switch state. electrictemperature-operated The compensating element ladder 2 is installed in the fluid reservoir so that the temperature of the fluid can be detected. Ru.

This compensation element often works in conjunction with the control device to activate the warning device below the critical fluid temperature. to prevent

This type of temperature-compensated fluid differential pressure warning device has traditionally had its temperature-activated compensation element It has the disadvantage of being attached to a boat. This boat makes the temperature A liquid flow is configured between the actuated element and the fluid to control the temperature of the temperature actuated element. Maintain the temperature of the moving object.

This boat requirement requires extra manufacturing steps and creates critical leak points. Change IC1 Wiring in and out of this element must be provided.

Temperature compensated fluid pressure differential warning devices with mechanical temperature actuated elements are in many respects detailed above. similar to devices with electrical type temperature actuated elements. This representative one is 1 Heyman et al. 1 (granted U.S. Patent No. No. 3,146.757. In this reference, the fluid temperature changes automatically. A cymbal type with multiple bimetallic bellows-shaped discs that expand and contract due to structure is disclosed. This gin/mill type structure has a corresponding clogging fill fin Mechanically prevents the indicator from indicating a blind filter condition at low temperatures. That's it.

Such mechanical type temperature-compensated fluid differential pressure warning devices have a mechanical temperature-activated compensating element. Due to wear failure, scale adjustment is difficult and assembly is extremely complicated and expensive. There are drawbacks.

The present invention solves one or more of the problems mentioned above.

Disclosure of invention According to one feature of the invention, the switch includes a housing and a first and a second terminal moved within the housing between the first and second positions. It has a plunger that can move. The first equipment is installed at the first and second terminals. electrically in response to the plunger occupying one of the first and second positions during the null. Configure the connection. A solid-state second device is placed inside the housing and the The preselected portion of the second device is within the preselected temperature range. electrical connection and electrical isolation between the first and second terminals in response to Get the selected one.

When the fluid pressure across an element or circuit of a fluid system exceeds a predetermined limit of 1 shift, There are numerous situations in which it is useful to indicate the timing. For example, in construction equipment An oil filler to bypass the oil refill when the oil fill becomes clogged. Usually, a router bypass circuit is provided. Displacement in response to the occurrence of a bypass condition A warning device is activated by the display switch. However, when the oil is cold, Even if the filter is new, the hydraulic pressure before and after it may exceed this predetermined limit. can be obtained. Provide a sump device to prevent the suction device from operating when the oil is cold. is promising.

Displacement display switches of the type where the connection arrangement works in conjunction with the indication of high differential pressure conditions. If the temperature-sensitive conductive element is in electrical contact with the terminals of the switch, It has been found that temperature compensation can be carried out by This temperature feeling The reactive conductive element is preferably placed in thermal contact with the special fluid, and the override and The switch works to maintain low differential pressure conditions within a certain temperature range regardless of the actual differential pressure conditions. For a better understanding of the invention, reference is made to the attached drawings. .

FIG. 1 is a schematic partial cross-sectional side view of an embodiment of the present invention, and FIG. 2 corresponds to FIG. 1. FIG. 6 is a schematic side view, partially in section, of a preferred embodiment of the present invention; The access button of the fluid bypass valve with the 70 langeer pressed against the terminal Located at FIG. 4 is a schematic side view corresponding to FIG. 6 with the spool separated from the plunger; FIG. 5 is a schematic diagram of a filter and a temperature-compensated displacement display switch; FIG. 6 is a partially cross-sectional schematic side view of another embodiment of the present invention; FIG. 7 is a schematic side view, partially in section, of yet another embodiment of the invention.

The drawings do not define the invention and are merely for illustrative purposes.

BEST MODE FOR CARRYING OUT THE INVENTION In the drawings, reference is made to a temperature-compensated displacement display switch that illustrates part of the principle of the present invention. They are collectively shown in number 10. Regarding the following temperature compensated displacement display switch 10 The detailed description should be understood in terms of the best currently known practice of this improvement. No. As is obvious to those skilled in the art, the temperature compensated displacement display switch 10 is the basic feature of this improvement. Many other embodiments can be taken without departing from the idea.

In the case of a preferred example of the temperature-compensated displacement display switch 10 shown most clearly in FIG. The first and second terminals 12.14 are installed within the Ujifugu 16. Ru. Terminals 12 and 14 each have a contact surface formed in No-Ujifugu 16. 17 and connection ends 1 to 18 exposed outside the housing 16. This connection The contact surface 17 and the connecting end 18 of each terminal 12.14 are formed of one continuous metal piece. It is preferable that the device be placed in close electrical contact, such as by placing the device in close electrical contact. However, after As is clear from the above, in one embodiment of the switch 10, the connecting end 18 and the terminal 1 2.14 A thermistor or other temperature sensitive device that can be placed in series with one contact surface of the A sex device is provided. The terminal connection 18 is connected to an electrical motor, as is well known to those skilled in the art. It is designed to be connected to a monitor device 22. This electrical monitoring device 22 It is preferable to incorporate a microgross setzer, but in other ways... It can also be converted into

Housing 16 does not provide an electrical path between terminals 12.14. . In the preferred embodiment, the housing 16 is, for example, a General Electric yALox 42Q, PBT, filtration glass-loaded plastic manufactured by Kook Co., Ltd. This is achieved by making it from an insulating material such as.

Separately, the housing 16 is made of conductive material and the terminals 12 and 14 are connected to each other. It can also be insulated from the housing 16 with iron sleeves.

...Using 16 has a first end portion 19 and a second end portion 20-\ have. Access to the terminal 12.14 is provided at the first end 19. The second end portion 20 is provided for connection with an electrical monitoring device, and the second end portion 20 has an actuating element. 24 can be attached to this so that it can be operated. This temperature compensation displacement table What is monitored by the indicator switch 10 is the displacement movement of a particular part of the actuating element 24. be. In the preferred embodiment, this actuating element 24 is a displacement indicator frame having a spool 26. This is a filter bypass valve 27. Generally speaking, the actuating element 24 is A device having a movable element 26 that moves linearly in response to a specific condition occurring. be.

The spool 26 is activated when the pressure across the filter 28 of the fluid device 31 exceeds a predetermined value. Accordingly, movement can be made from the first spool position to the second spool position. Preferred embodiment When the spool 26 moves away from the temperature compensated displacement display switch 10, the spool 26 moves away from the temperature compensation displacement display switch 10. This indicates that the filter 28 is clogged. Filter 28 and bypass valve 27 Also, the hydraulic relations of the temperature compensation displacement display switch 10 are schematically shown in FIG. . Bypass valve 27, filter 28, switch 10 and electrical monitoring device 2 1 constitute a filter monitor device 29 in total.

In preferred embodiment 1, the second end portion 20 of the housing 16 includes a filter bypass valve. 6 and 4 so that it can be received in the threaded hole 30 in the 1 (as best shown, the spool 26 approaches the switch 10 and You can move away from it.

Compensated displacement indicating switch 10 (c) indicates that actuating element 24 is in one of said first and second positions. configuring electrical continuity between the first and second terminals in response to occupying one terminal; A device 41 is included. Specifically, the housing 16 includes a second end portion 2. 0 to the contact surface 17 of the terminal 12° 14 is defined. ”. Within this first opening 32 are a contact surface 38 and a stop surface 40 in the preferred embodiment. A plunger 36 having a diameter is located therein. The plunger 36 is located within the opening 32 in the first orifice. and a second position.

In the first position, the flanger contact surface 38 is in contact with both terminals 12.14. Ru. In the second position, the flanger contact surface 38 is separated from the contact of the terminal 12.14. It is.

A stop 42 is attached to the second end portion 20 of the housing 16. This space The top 42 includes an annular diagonal defining a second aperture 44 having a smaller diameter than the first aperture 32. Preferably, it is a school. The first and second openings 32.44 are coaxially formed. Preferably. In the second position, the plunger stop surface 40 It is in contact with 42. This is clearly illustrated in FIG. suitable fruit In this embodiment, the first aperture 32 and the plunger 36 are generally cylindrical and the plunger 36 has a substantially cylindrical shape. They have a common axis that determines the direction of movement.

A device 52 is provided to force the plunger 36 towards the stop 42. suitable In this case, this bias device 52 is located between the housing 16 and the plunger 36. It consists of a coil spring 54. As clearly shown in Figure 1, 1 opening 32 is separated from the second section 20 by the end wall 56. It is bounded. The first spring seat opening 58 extends from this end wall 56... It extends towards the first end portion 18 . Similarly, plunger 36 has plunger contact. a second splash seat extending from face 38 in a direction 1c away from plunger stop face 40; An aperture 60 is defined. The first spring seat opening 58 allows the first end 62 of the spring 54 to A second spring seat aperture 60 receives a second end 64 of spring 54 . In Figure 3 As clearly shown, plunger contact surface 38 or terminal 12.14 It is advantageous to size the spring 54 so that it is not completely compressed when it comes into contact with the It is.

Silanger 36 preferably includes a main diameter element 66 and a conductive element 68. Main body - element 66 has an axially off-center position between plunger 36 and first opening 32; a guide portion 70 sized relative to the first opening 32 to prevent There is. More specifically, each of the guide portions 70 has an actual It includes multiple pieces of fins 72 that are in contact with the fins 72 . The space between the fins 72 allows the second opening. Fluid communication between port 44 and terminals 12 and 14 is enabled. This guide part 70 and The fins 72 are also clearly shown in dotted lines in FIG.

A conductive element support portion 74 extends from the guide portion 70 in the direction of the end wall 56 . This branch The holding portion 74 is cylindrical in shape and has a smaller diameter than the guide portion 70. In the preferred embodiment, The conductive element 68 is a circular brass member press-fitted to the support portion 74. . As best shown in FIG. 3, the electrically conductive element 68 is connected to the housing first end portion In response to the plunger 36 being pushed up toward the terminal 19, the conductive element 68 12 and 14 and is shaped and located in such a way that it makes conductive contact with both.

As previously mentioned, the preferred embodiment of temperature compensated displacement indicator switch 10 includes conductive element 68. When pressed against the terminal contact surfaces 17 an electrical connection is established between the contact surfaces. A mechanical switch is included. Other machines related to the principle of this improvement It will be understood by those skilled in the art that standard switches may also be used. Example: Eha, one One terminal has a movable part, and inward movement of the plunger causes the other terminal to move. Terminal 1 (also a type of mechanical switch that makes physical and electrical contact) Can be used.

A protrusion 76 of plunger 36 extends from guide portion 70 in a direction away from end wall 56. ing. The protrusion 76 has a truncated conical shape and has a main diameter smaller than the diameter of the second opening 44. It has a main diameter and can extend through the aperture. The protrusion 76 is the thickness of the stop 42 and the distance traveled by the plunger 36 in the housing 16. Preferably, it extends from section 70. K, as shown most clearly in Figure 6 above. The protruding portion 761 (in response to the acting spool 26 the conductive element 68 must be contact terminal 12.14. If the length of this protrusion 76 is not sufficient, the width may be insufficient. One spool 26 comes into contact with the stop 42 and stops, moving the plunger 36 sufficiently. Do not cause conductive element 68 to contact terminal 12.14.

Additionally, a second device 78 is provided and responsive to the device being within a predetermined temperature range. Establishing an electrical connection between the first and second terminals 12.14. Preferably, this The second device 78 consists of a thermistor with a positive temperature coefficient of resistance and is It is located between terminals 12 and 14. This is the United States pennlupanyasentoma R'L 3006- manufactured by Keystone Carbon's thermistor department in Lee 50-25-PTOPTC is preferred. This thermistor can withstand temperatures above 50℃ It has a relatively large resistance at temperatures below 50°C, and a relatively small resistance at temperatures below 50°C. ing. Displacement with other desired temperature sensitivities using thermistors of other values It will be understood by those skilled in the art that an indicator switch 10 could also be provided. Use server Preferably, the mister has an abrupt transition between its high and low impedances. stomach. That is, the thermistor will move from a low impedance state over a relatively short time interval. It is preferred to move to a high impedance state.

The thermistor is preferably located in the sixth recess 80 between the two terminals 12.14. I don't like being let down. The first and second leads 81.83 of the thermistor are connected to the thermistor. Connect the stars to corresponding portions of the first and second terminals 12.14. sixth Preferably, the recess 80 is in fluid contact with the second opening 44. , the first opening 32, the second opening 44, the first spring sort opening 58 and the sixth recess. The fluid passageway 991 is further established by the groove 80. Therefore, the thermistor operates It is in fluid contact with element 24.

Another embodiment of the invention is shown in FIG. represented by a reference number.

In this embodiment, the housing 16' has an axially oriented central opening 82 extending therethrough. A single-opening lower 9 is formed.

This central opening 82 does not extend completely through the housing 16' and the first end portion 19 ' and terminates in an end wall 56' proximate the end wall 56'.

Plunger 36' is located within this central opening 82 and is axially movable. vinegar A top 42' is provided to limit movement of plunger 36' away from end wall 56'. be done.

This stop 42' preferably defines a second opening 44' as shown in FIG. It's a disc. The plunger 36' includes a main body element 66' and a relatively small cross-section. There is a protruding portion 76'. The protrusion 76' extends through the second opening 44' to the main body element 6. It protrudes from 6'. The main body element 66' has a projection 76'. The preferred embodiment includes a magnet 88 extending toward the distal position.

A device 52' is provided for pushing the plunger 36' towards the stop 42'. Ru. The biasing device 52' is located intermediate the end wall 56' and the plunger 36'. Preferably, the coil consists of springs. This bias device 52' and the sylanger 3 6' indicates that the holder 36' has moved sufficiently and the outermost end 89 of the protruding portion 76' has been moved. It is preferable to have a shape that allows it to be approximately flush with the outer surface 90 of the top 42'. stomach. This is shown in Figure 6.1 (shown). As time goes by, the plansy 1''36' is biased toward the main body element 6 by the action of the biasing device 52'. 6' is moved to a position where it contacts stop 42'.

The impedance of the electric circuit is increased in response to the appearance of a predetermined portion of the plunger 36'. A changing device 92 is located near the central opening 82. This impedance Both the gas changer 92 and the plunger 36' have actuating elements 24 in first and second positions. A device for forming an electrical connection between the two positions of the response port occupies either position. 41'. This impedance changing device 92 preferably includes a central opening 82. It is secured within a fourth aperture 94 which is slightly laterally off-centered. For the preferred embodiment , this impedance changing device 92 includes a normally open magnetic reed switch. The magnet 88 is located at the base end of the temple, and the magnet 88 is closed. When the head switch is tilted far away from the axial direction (C will open). ing. In the embodiment shown in FIG. 6, the outer end 89 of the projection element is near the outer stop surface 90. When the reed switch is closed, the outer end 89 of the protruding element exceeds the outer surface 90 of the It opens when it can project over a considerable distance. As is obvious to those skilled in the art, this device 92 may also be a Hall effect device, an optical proximity device, a capacitive device or many other types. A close-range type device may also be used.

,” establishing an electrical connection in response to the II Chronicles 2 device being within a predetermined temperature range. A second device 78' for distributing the liquid in the Ujifugu 16', preferably near the first opening 32'. positioned.

This electrical connection: sexual establishment device 78' is the same as that described above; 1. Impeder The second device 78' is connected in parallel (C-connected) to the first opening 32'. It is preferable that the opening be located within the fifth opening 96 at a position close to . In the case of the embodiment shown in FIG. If so, the fourth and fifth openings 94,96 are made to communicate with the first end portion 19'. ing. Once the corresponding elements are positioned within these openings 94,96, Apertures 94,96 become loaded, as is well known to those skilled in the art.

Applications that require rapid response to temperature changes (in some applications, impedance changes A portion of the fifth aperture 96 between the filling device 78' and the first aperture 32' is free of filling material. It is preferable to maintain the condition. This region is maintained in fluid communication with the first opening 32'. be done. In the preferred embodiment, this causes the fluid actuating the bypass valve to +C or 0 so that contact can be made with position 78' The embodiment of the temperature compensated displacement display switch 10 described hereinafter includes a displacement detection contact switch. A positive temperature coefficient thermistor is included in parallel with circuit 37. These examples displacement sensing contact switch 37 is adapted to close in response to a "no fault" condition. The thermistor responds to a “fault” condition when the temperature drops below a predetermined level. chosen and arranged to make it impossible. However, many or all of these improvements Temperature-compensated displacement display switches with other logical configurations can be developed using the I have to point out that.

For example, the movement of the actuating element towards the switch 10 or its −, , , Fl, ( - monitor the actuating element 24 in situations where the above indicates a potentially harmful condition; It is desirable to use the temperature compensated displacement display SINNO F10 for this purpose. This switch The first one is of the temperature coefficient type and is attached to terminal 12.14. Outside the point plate, which is in series rather than parallel with the circuit formed by the plunger 36 across is similar to the preferred or alternative embodiment switch.

That is, the negative coefficient thermistor is connected in this embodiment to the connection end 18 and the two It is connected in series to the contact surface 17 of one of the terminals 12.14. Warning system 2 2 monitors the switch applied to the low impedance condition. Activate warning devices in response to the detection of a problem. As in the previous embodiment, the use Thermistors have a relatively sharp transition from high impedance to low impedance. It is desirable to have a

Similarly, movement of actuating element 24 away from switch 10 is characteristic of a detrimental condition. conditions that appear due to low impedance conditions rather than high impedance conditions. using a temperature compensated displacement indicator switch to monitor the movable element 26 at is also desirable. Such a switch is such that the movable element 26 is moved away from the switch 10. In response to the displacement, a displacement detection contact switch 37 is connected between terminals 12 and 14. The format is such that a connection is established. This corresponds to stop 4 in the embodiment of FIG. 2' so that the reed switch 92 closes only when the plunger 36' extends. This is done by positioning the switch at . Apart from this, Figure 7 (C) A format can also be used. The negative temperature coefficient thermistor is connected to terminal 12", 1 4" in series with the circuit formed by the plunger 36". Warning system monitors the switch for low impedance A preferred embodiment of the switch 10 which activates the warning device in response to the detection of a condition is a filter bypass. Particularly applicable to fluidic devices incorporating pass circuits, which provide alarms in response to filter bleeds. Useful for activating alarm systems.

This switch 10 warns due to high viscosity of the fluid used in the fluid circuit when kept at a low temperature. Temperature compensation is provided so that no system activation occurs.

Regarding the operation of the temperature compensated displacement display switch 10, first a characteristic not related to temperature compensation is set. Considering only the signs is also better understood as considering the tail. Displacement detection of switch 10 Contact portion 37 contacts terminal 1 in response to plunger 36 assuming the first position. 2.14 (relatively low impedance condition and relatively high impedance condition) 70 in response to the langeer 36 being in the second position. Establish a high impedance condition and another relatively low impedance condition.

More generally, this displacement detecting contact portion 37 is formed when the movable element 26 and in one of the second positions to establish an electrical connection between the terminals 12 and 14. A device 41 for establishing the same. Due to the movement of this plunger 36, The change between the pedance conditions is in one of the first and second positions in the preferred embodiment. Creates an electrical contact between the two terminals 12.14 only when the This is achieved by including a conductive element 68 on the plunger 36 that establishes the conductance. will be accomplished.

According to other embodiments, this change in impedance condition is a Position magnet 88 and reed switch 92 in series with terminal 12.14. It is caused by 2. Reed switch due to movement of magnet 88 Changes in the magnetic flux at the tip 92 create a planoposition between the first bite and the second position. As the carrier moves, a change in the opening and closing conditions of the switch 92 is effected. Those skilled in the art should Opening and closing the intermediate circuit of terminals 12.14 in response to movement of plunger 36 Other suitable devices may be used for this purpose.

The warning system constantly monitors the impedance of switch 10. switch 10 The analogy is that the response has an impedance that clearly indicates a clogged filter condition. alarm and other warning indicators are activated by the warning system.

As mentioned above, the important feature of this switch 100 is that it does not work in a certain temperature range. One of the impedance conditions is not allowed. That is, except within a specified temperature range. The switch 10 detects the occurrence or non-occurrence of a certain condition depending on the impedance change. Establish display. Within this given temperature range the switch conditions are is unrelated.

Preferred implementations of the invention such that high impedance conditions represent occluded filter conditions In the example case, the high impedance condition extends over a temperature range where the fluid is relatively viscous. It is not allowed. Positive temperature coefficient thermistor inside terminal 12.14 the temperature below the thermistor's transient temperature, which in the preferred embodiment is 50°C. A low impedance path is obtained between the terminals.

This switching temperature can be established at other points by selecting the appropriate thermistor value. Wear.

In summary, switch 10 closes filter 28 in warm fluid operating conditions. Distinguish between bypass conditions caused by viscous fluids and cold operating temperatures be able to. Therefore, the switch 10 is activated at a fluid temperature above a predetermined level. The warning system is activated only when the pass condition occurs. However, the first In a second temperature range, we obtain an output that depends on the position of the moving element, while in a second temperature range we obtain an output that depends on the position of the moving element. The wide utility of switch 10 in obtaining power will be apparent from the foregoing.

Other features, objects, advantages and uses of the invention may be further understood from the drawings, description and other features. obtained by examining the claims of the genus. Preferred implementation of temperature compensation displacement display switch 10 By way of example, the claims may be departed from in many ways different from those detailed above. (It must be understood that this can be realized.

international search report 1”+elfiMbonaljtpO”CIhonNo, PCT/lJsi12 100055 Continuation of page 1

Claims (1)

[Claims] 1. A switch responsive to the position of the movable element (26) within a first predetermined temperature range (10), the movable element is in first and second positions relative to said switch (10). within a second predetermined temperature range, the switch (10) There is no doubt that the switch (10) is responsive to the position of the dynamic element (26). ・Using (16) and extending into said housing (16) and respectively connected to a switch monitor device (22). first and second terminals (12) having connecting ends (18) adapted to be connected to each other; , 14) and forward in response to said movable element (26) occupying one of said first and second positions. a first device (41) for establishing electrical continuity between the terminals (12°14) )and, the second device (γ8) to ensure that the device (78) is within the second predetermined temperature range; in response to a high impedance condition and a low impedance condition between said terminal connection end (18). maintaining a predetermined one of the pedance conditions and within the first predetermined temperature range. The impedance between the terminal connection ends (18) is determined by the first device (41). and the second device (γ8) for enabling the control to be substantially controlled. , the second device (78) is in a liquid state and is in the no-ujinda (16). located at the switch (10). 2. The switch (10) according to claim 1, wherein the second device (78) is Electrical connection is made to the corresponding one of the first and second terminal connection ends (18), respectively. includes a thermistor having first and second leads (81, 83) in contact; , switch (10). 6. The switch (10) according to claim 2, and the thermistor (78) is of a positive temperature compensation type, and has a relatively high resistance within the first predetermined temperature range. has a relatively low resistance within the second predetermined temperature range, and has a relatively low resistance within the second predetermined temperature range; switch (10), the temperature range being higher than the second predetermined temperature range; 4. The switch (10) according to claim 6, wherein the first device (41) is , in response to said movable element (26) occupying the first element position. The element (24) occupies the second position on the previous day. The plunger (36) now assumes the second plunger position in response to the including a switch (10). 5. The switch (10) according to claim 4, and the plunger (36) includes a conductive element (68), said conductive element (68) being in front of said plunger (36). in response to the first and second franchisors being in one of the first and second franchisor positions. and the second terminal (12°14) to establish electrical continuity between them. Now, switch (10). 6. The switch (10) according to claim 5, and the housing (16) defines a fluid path (99) between the thermistor (78) and the movable element (26). The fluid path (99) is configured to provide fluid between the thermistor and the movable element (26). A switch (10) that establishes contact. Z The switch (10) according to claim 4, and the front mb plunger (36 ) in response to the proximity of a predetermined portion of the first and second terminals (12, 14). a switch (10) further comprising a device (92) for establishing electrical contact between . 8. The switch (10) according to claim 6, and the proximity/detection contact establishment The device w (92) includes a magnetic reed switch, and the plunger (36) a switch including a magnet (88) located at said predetermined portion of the switch (36); (10). 9. The switch (10) according to claim 1, wherein the terminal (12, , 14) each have a contact portion (17) distal to the corresponding connection end (18), and The first device (41) is configured such that the movable element (26) is in one of the first and second positions. contact portion (11) of each terminal (12, 14) in response to A switch (10) establishing electrical contact between. 10. The switch (10) according to claim 9, the second device (78) is the contact 1m part (17) and one connecting end (18) of the terminal (12, 14) A switch (10), which is a two-terminal device connected in series between. 11 The second device (78) is a switch (10) according to clause 10 of the poem request. is a negative temperature coefficient variety thermistor, and within the second predetermined temperature range, the a switch having a high resistance and a relatively low resistance within the first predetermined temperature range; tch (10). 12. The switch (10) according to Clause 11 of the claim, the above-mentioned (16) is a fluid path (9) between the thermistor (78) and the movable element (26). 9), the V fluid M (99) connects the thermistor and the movable element (26). the first and second ends 13--Uzonda (16) establishing fluid contact between them; and a second terminal (12, 14), and the first and second terminals (12, 14) , 1'4) are separated and located within the housing (16), and the first and and a plunger (16) movable with respect to the housing (16) between the first and second positions. 36) and said plunger (36) in one of said first and second positions. establishing electrical continuity between the first and second terminals (12, 14) in response to a switch (10) having a first device (41) for said second device (7); 8) is within a predetermined temperature range. 2, 14) has a second device (γ8) for obtaining electrical continuity between the characterized in that it is a thermistor located across the terminals (12, 14) K; switch (10). 14 The switch according to claim 13 (with 1o>', the thermistor is It is of a positive temperature coefficient type, and the plunger (36) switch (10) located parallel to the electrical path established across (12, 14); . 15. A switch (10) according to claim 14, wherein the thermistor is A switch (10) in fluid contact with the langeer (36). 16. The filter monitor device system (29) has a) filter (28). a fluid device (31); a device (24) for monitoring the pressure difference across the filter (28); , C. For the displacement display switch (10), 1 contact part (1γ) and connection part, respectively. first and second terminals (12°14) having a minute (18); II. The pressure difference is a preselected one of above and below a predetermined level. electrical connection between the first and second terminal contact portions (17) in response to a first device (41) for establishing a connection; 111 The temperature of the switch (10) is above and below the predetermined level. the first and second terminal receiving portions (in response to the preselected one); 18) To maintain a preselected one of high and low impedances between said displacement table having a second device (78) which is independent from said first device (41); an indicator switch (10); 2. The impedance of the first and second terminal connection parts (18) monitor the impedance across the first and second terminal contact vc portions (18). - Electricity bill monitor to establish a warning signal in response to a dance or a predetermined range of depreciation. a monitor warning system (22), and the monitor warning system (22) is connected to the terminal (12, 14) are now connected to the H contact portion (18) of each A filter monitor device system including the monitor warning device system. 17. A filter monitoring device system (29) according to claim 16, comprising: A first device (41) is configured such that the differential pressure across the filter (28) is below a predetermined level. in response to establishing electrical continuity between the first and second terminals (12°14). The second device (78) is arranged in front of the switch (10). between the terminals (12, 14) in response to the temperature being below a predetermined level. A filter monitoring device system designed to establish low impedance. 18. A filter monitor device thread according to claim 17, wherein the second device (78) is a filter including a thermistor across said terminals (12, 14); Monitor device system. 19. A filter monitoring device system (29) according to claim 16, comprising: A displacement indicating switch (10) is in fluid contact with the fluid arrangement (31) and is in fluid contact with the fluid arrangement (31). 2 device (78) is free from separation from said fluid at said switch (10). There is a filter monitor system. 20, (filter monitoring device system (29) according to claim 16) The first device (41) is a plug located at least partially within the switch (10). a holder (36), the franchiser (36) is capable of adjusting the difference across a predetermined level A filter monitoring system movable between first and second positions in response to pressure. 2. The filter monitoring device system (29) according to claim 20, Note 1 device (41) is further connected across the front terminal (12, 14). a proximity switch (92), and the sealant (36) is a proximity switch control. A filter monitoring device system including a roll element (88). 22. A filter monitoring device system (29) according to claim 21, comprising: A proximity switch (92) is configured such that the grandeur (36) is in the first and second positions. A filter monitor device system that is closed in response to one of the 26. A filter monitoring device system according to claim 20, wherein the silane filter The shutter (36) passes through the electrically conductive element (68) and connects the electrically conductive element (36) with the electrically conductive element. (68) means that the 70 range gear (36) is in one of the first and second positions. in response to the conductive element (68) or the terminals (12, 14) A filter monitor configured and arranged to make electrical contact with the -Equipment system. 24 The filter monitoring device system according to paragraph 22 or 23 of the scope of the poem, The second device (78) is located across the first and second terminals (12, 14). A filter monitoring device system including a mounted positive temperature coefficient type thermistor. 25. Filter monitoring device system according to claim 22 or 26 (29) Then, the second device (78) connects to one of the terminals (12, 14). A negative temperature coefficient type plate located in a row between the contact part (17) and the connection part (18). Filter monitoring device system including thermistor. 26, h Claim 161 A switch (10) according to the shell, said second device ( 78) is a contact portion (of one of the first and second terminals (12, 14)); 17) and the connecting end (18). , switch (10). 27. The switch (10) according to claim 26, wherein the second device (78 ) is a thermistor of the negative temperature coefficient variety, and the thermistor is a relatively high resistance below the temperature level and a relatively low resistance above the predetermined temperature level. A switch (10) having: