BRPI0621749A2 - vertical fluid level meter to display a fluid level in a sealed container, and power transformer - Google Patents

Abstract

VERTICAL FLUID LEVEL METER TO DISPLAY A FLUID LEVEL IN A CLOSED CONTAINER, AND, ELECTRIC POWER TRANSFORMER. A calibrable vertical fluid level meter (2) for displaying a fluid level in a closed container (1) includes a float portion (6) and a meter portion (4). The float portion (6) is arranged inside the closed container (1) and converts a vertical displacement of a float (10) into a rotational displacement of a first rotating member (26). The meter portion (4) is arranged on the outside of the closed container (1) and includes a second rotating member (34), a pointer (38), and a clutch mechanism (42). The meter portion (4) is arranged with respect to the float portion (6) such that the second rotating member (34) is rotatably coupled to the first rotating member (26). The clutch mechanism (42) selectively engages the pointer (38) to the second rotating member (34) and disengages the pointer (38) from the second rotating member (34) to allow movement of the pointer (38) with respect to the second rotating member ( 34) to calibrate the meter (2).

Description

"VERTICAL FLUID LEVEL METER TO DISPLAY A FLUID LEVEL IN A CLOSED CONTAINER, AND ELECTRIC POWER TRANSFORMER" BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates to float liquid level meters. More specifically, the invention relates to a liquid level float meter that can be recalibrated after installation.

RELATED ART DESCRIPTION

Conventional liquid level meters are known to measure and display the level of a liquid in a sealed container, for example a container including an electrical power transformer. Such a meter, generally called a vertical liquid level meter, is disposed on a top of the container and includes a float disposed within the closed container and in contact with the surface of a dielectric fluid at least partially covering the transformer. When the level (ie height) of the liquid changes, the float is shifted vertically.

The vertical displacement of the float is then converted to a rotational motion, which rotational motion causes rotation of a first internal magnet arranged on the float, under a seal formed between the container contents and the atmosphere, and near a container top. closed. The inner magnet is magnetically coupled to a second outer magnet disposed on (i.e. on the atmosphere side) the seal formed between the container contents and the atmosphere. Therefore, rotation of the internal magnet causes rotation of the external magnet.

An axis is fixed with respect to the external magnet such that rotation of the external magnet causes corresponding rotation of the axis. Arranged at the distal end of the shaft, opposite the external magnet, is a pointer, or indicator, which, together with a meter dial, displays the liquid level in the container. Such conventional meters, however, are not readily calibrated and subsequently recalibrated. Specifically, because the axis is fixed to the external magnet, and because the pointer is fixed to the axis, the position of the pointer with respect to the height of the float is preset. Thus, for example, if an initial liquid height is different from housing to housing, the initial reading of meters in the housing will be different. However, it may be desirable to have an initial level, whatever the level, associated with a single pointer position. Similarly, if the nominal liquid level changes, it may be desirable to recalibrate the meter to adjust this level to the single pointer position.

Therefore, there is a need in the art for a simply constructed liquid level meter that is easily calibrated and recalibrated.

BRIEF SUMMARY OF THE INVENTION

This invention addresses the prior art needs by providing a modern liquid level meter, in which a rotating liquid level indicator is movable in conjunction with the translational displacement of a float, but also relative to the translational displacement, to calibrate the meter.

In a first aspect of the invention, a vertical fluid level meter for displaying a fluid level in a closed container includes a float portion and a meter portion. The float portion is disposed within the closed container and includes a float and a first rotating member. The float portion converts a vertical float displacement caused by a change in fluid level to a rotational displacement of the first rotating member. The gauge portion is disposed on an exterior of the closed container and includes a second rotating member, a pointer, and a clutch mechanism selectively engaging the pointer to the second rotating member. The meter portion is arranged with respect to the float portion such that the second pivot member is rotatably coupled to the first pivot member. The clutch mechanism selectively engages the pointer with the second rotary member such that the pointer rotates with the second rotary member to provide a visual indication of fluid level, and disengages the second rotary member pointer to allow movement of the pointer with respect to the second member. swivel

In another aspect of the invention, a vertical fluid level meter for measuring a fluid level in an enclosed space includes a rotational member, a rotary mechanism, a clutch member, and a relative movement facilitator. The rotational member has a rotational position corresponding to a vertical height of a float arranged in the enclosed space. The rotary mechanism is in communication with the rotational member. The mechanism includes a pointer that indicates to an observer the rotational position of the rotary mechanism. The clutch member propels the rotary mechanism against the rotational member with sufficient thrust to engage the rotary mechanisms with the rotational member, thereby rotating the rotary mechanism with the rotational member. The relative movement facilitator is arranged on at least one of the rotational member and the rotary mechanism to allow the thrust provided by the clutch member to be overcome, thereby disengaging the rotary mechanism of the rotational member to rotate the rotary mechanism with respect to the Rotational member.

In a still further aspect of the invention, a vertical fluid level meter for displaying a fluid level in a closed container includes a float portion, a second magnet, a pointer, and a clutch mechanism. The float portion has a first magnet that rotates correspondingly with a change in fluid level in the container. The second magnet is disposed outside the container and is magnetically coupled to the first magnet such that the second magnet rotates correspondingly with the first magnet. The pointer mechanism provides a visual representation of the rotational position of the second magnet. The clutch mechanism selectively engages and disengages the pointer mechanism with the second magnet such that the pointer mechanism rotates and with respect to the second magnet, respectively.

A better understanding of these and other objects, features, and advantages of the invention may be had by reference to the figures and detailed description of the invention, which illustrates and describes preferred embodiments of the invention.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a perspective view of a fluid level monitoring meter in accordance with a preferred embodiment of the invention.

Figure 2 is an exploded perspective view of the float portion of the fluid level monitoring meter of Figure 1.

Figure 3 is an exploded perspective view of the meter portion of the fluid level monitoring meter of Figure 2.

Figures 4A and 4B are top elevation view detailing the relationship between a key and a cam surface of a rotary mechanism according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A preferred vertical oil level gauge will now be described with reference to Figures 1-4.

As illustrated in Figure 1, a vertical fluid level gauge 2 in accordance with the present invention generally includes a gauge portion 4 and a float portion 6. The vertical gauge 2 is mounted on a top of a fluid-containing container 1 3, such as a dielectric fluid at least partially covering a transformer (not shown) contained within container 1. In the described embodiment, container 1 includes a body 1a and a vertical tube Ib fixedly mounted to a top of body 1a.

Thus assembled, the meter portion 4 is disposed outside the container 1 and the float portion 6 is disposed within the container 1 (e.g. within the tube 1b). For example, a threaded neck 8 may be provided between the meter portion 4 and the float portion 6. The threaded neck 8 is preferably engageable with a standard threaded opening provided in the conventional container. When the meter 2 is disposed in the container, the meter portion 4 is preferably rotatable with respect to the threaded neck such that the meter may be oriented according to user preference.

The float portion 6 of the vertical fluid level meter 2 will now be described with reference to Figure 2. In the preferred embodiment, the float assembly includes a pair of generally cylindrical shaped floats 10a, 10b. A block 12 is disposed between the two floats 10a, 10b. The floats 10a, 10b and block 12 are preferably disposed on and attached to a float tube 14. One or more of the block and floats may be attached to the float tube 14. End caps 16 are preferably provided to hold the floats 10a. 10b and block 12 in tube 14. In addition, a float pin 18 is preferably disposed in block 12. A distal end of the float pin 18 protrudes radially outwardly from block 12, a distance greater than an outside diameter of the Buoys.

The floats 10a, 10b, block 12, and float tube 14 each include an opening formed axially therein, and are arranged for relative movement with respect to an axis 20 in a translational or axial direction. At least block 12 (and thereby float pin 18) is fixed to the shaft in a rotational direction, such that when the float block and pin rotate about an axis of the shaft, the shaft rotates therewith. For example, two roller pins 19 are tightened in block 12 and are arranged at least partially in the opening axially formed by block 12. Axis 20 preferably has a square cross section and the two roller pins are arranged near opposite sides of the axis. 20. In this manner, the float pin 18 moves relative to the axis in the direction of the axis line of axis 20, but rotation of block 12 over the axis line of axis 20 will also cause rotation of axis 20. Other couplings are also contemplated. which allow the block (and thus the buoys) to move relative to the axis in a transverse direction and to rotate the axis as the block rotates, that is, to transform linear motion to rotational motion.

A support tube 22 is positioned over the floats, block, float tube, and shaft, and an opening 24 is arranged on the outer surface of the support tube 22. When the float portion 6 is mounted, the distal end of the support pin float 14 is captured in opening 24. In this manner, opening 24 acts as a guide for rotational movement of the shaft by float pin 18. More specifically, a change in fluid height within the container causes the float to move axially with with respect to the support tube. Forming aperture 24, for example, helically over support tube 22, translational movement of the float within the tube support will also result in rotational movement of the block in which the float pin is disposed. In this way, movement of the float in an axial transverse direction results in shaft rotation because the shaft is rotatably attached to the float pin.

A first magnet 26 is attached to the top end of the shaft 20, such that when the shaft 20 rotates, so does the first magnet 26. The first magnet is preferably disposed within a housing 28. The housing 28 preferably also includes the threaded neck 8 which facilitates attachment of the meter to a conventional container.

The upper meter portion 4 will now be described with reference to Figure 3. The meter portion 4 preferably includes housing 28, and a cover 30 disposed in housing 28. Housing 28 and cover 30 form a substantially cylindrical housing in which the Internal components of the meter are housed. The cover 30 preferably includes a cutout providing a viewing area for viewing at least one pointer representing the fluid level in the container, as will be described in more detail below.

A pointer assembly 32 is disposed within housing 40 to provide a visual representation of the fluid level in the container. The pointer assembly preferably includes a second magnet 34, a lower hub 36, and a cam / pointer mechanism 38. The lower hub 36 preferably is fixed with respect to the second magnet 34. Therefore, when the second magnet 34 rotates about a shaft, lower hub 36 also rotates about that shaft.

The second magnet 34 is disposed within the housing 28 so as to be in communication coupled with the first magnet 26 of the lower float portion 6. In particular, the float portion 6 and the pointer assembly 32 are arranged with respect to the housing 28 as such. that a rotation axis line for the float assembly axis 20 is coincident with a meter assembly rotation axis line 32. A seal is preferably formed within the housing 28 between the first magnet 26 of the float portion 6 and second magnet 34 of pointer assembly 32 of meter portion 4. The seal retains fluid within the container without leaking into the atmosphere, but rotational displacement of the first magnet disposed within the container is transferred to the second magnet disposed outside the container.

The cam / pointer mechanism 38 is preferably engaged with the lower hub and second magnet with a clutch. Accordingly, the cam / pointer mechanism is both movable with and with respect to the lower hub 36 and second magnet 34. In particular, a clutch mechanism 42 is preferably provided to facilitate clutch engagement. For example, as shown in the preferred embodiment of Figure 3, the cam / pointer assembly 38 is disposed on the lower hub 36 and a fastener secures the cam / pointer assembly to the lower hub. For example, a nut 35 may be tightened to a threaded portion of the lower hub 36 to secure the cam / pointer assembly to the lower hub. In addition, a lock washer 43 is provided between the cam / pointer mechanism 38 and the nut 35.

During normal operation, nut 35 and lock washer 43 apply sufficient axial force to the cam / pointer mechanism to maintain a fixed relationship between the lower hub and the cam / pointer mechanism. Accordingly, the cam / pointer mechanism 38 rotates together with the second magnet. However, when the axial force coupling the cam / pointer mechanism 38 to the lower hub 36 is exceeded, the cam / pointer mechanism may be moved relative to the lower hub 36. To facilitate this relative movement, the lower hub 36 is formed with a groove 37 on a top of it. A tool, for example, a flat head screwdriver may be used in conjunction with opening 37 to prevent rotational movement of the lower hub (and thus the second magnet), thereby overcoming the force applied by the clutch mechanism 42, and the mechanism cam / pointer 38 is rotatably movable. For example, a user may move the cam / pointer mechanism 38 simply by grasping the cam / pointer mechanism 38 and manually rotating it.

The cam / pointer mechanism 38 preferably includes a pointer 38a and a main body 38b having a cam surface. The pointer 38a extends radially outwardly from the main body 38b. In particular, pointer 38a preferably consists of an arm extending radially outwardly from the cam body and a flanged flap extending substantially axially to a distal end of the arm. The cam / pointer mechanism is preferably arranged such that the pointer 38a is arranged near a dial 44 disposed in the viewing area provided by the cutout 31 in the cover 30. The relative position of the pointer 38a with respect to the dial indicates the fluid level within. from the container. In the preferred embodiment of the invention, the cam surface and the pointer are arranged as a unitary structure. Alternatively, the cam surface pointer 38a and main body 38b may be manufactured as separate components, and then assembled or otherwise fixed with respect to each other.

As should be appreciated from the foregoing discussion, when the fluid level in the pressurized vessel changes, that is, when the level rises and falls, the floats 10a, 10b correspondingly rise and fall. When the floats are raised and lowered, the float pin 18 cooperates with the groove 24 formed in the support tube 22 to rotate the shaft 20 and first magnet 26 attached to the float portion 6 of the meter 2. This rotation of the first magnet 26 also causes rotation of the second magnet 34 disposed on the meter portion 6 of the meter 2. The second magnet 34 is coupled to the cam / pointer mechanism 38 by the clutch mechanism such that the cam / pointer mechanism also rotates and the position of the pointer 38a of cam / pointer mechanism 38 with respect to dial 44 provides an observer with a visual indication of the fluid level within the container.

In addition to providing a visual indication of the fluid level, the present meter may also be readily recalibrated because the cam / pointer mechanism 38 may be moved relative to the first and second magnets 26, 34 by the clutch mechanism described above. The meter can also be recalibrated. That is, the cam / pointer mechanism 38 can be moved relative to the second magnet 34, so an operator can calibrate meter 2 such that the position of the pointer 38a of the cam / pointer mechanism 38 matches any position of the float (and thus any fluid level position within the container).

In conventional containers it is desirable to keep the fluid level in the container within an acceptable range, ie between a minimum and a maximum level. To this end, the present invention provides one or more fixed-point keys 46 arranged near the body 38b of the cam / pointer mechanism 38 to operate in conjunction with the cam surface formed on the body 38b of the cam / pointer mechanism 38 to signal when a fluid reaches a fixed level. Each of the keys 46 preferably includes a key body 46a, a cantilever arm 46b, and a roller 46c disposed at a distal end of the cantilever arm 46b. The keys 46 are activated when the cantilever arm 46b is offset relative to the key body 46a.

As best illustrated in Figure 4, the cam surface of the body 38b of the cam / pointer mechanism 38 is formed with multiple radii. Specifically, the cam surface preferably includes a normal region having a first radius, and an alarm region having a second radius, different from the first radius. Preferably, the roll 46c of each of the keys 46 is arranged to travel along the cam surface when the cam / pointer mechanism 38 rotates with respect to the key 46. The radius of the normal region of the cam surface is such that the roll scroll along without activating the key. However, the alarm surface of the cam surface has a smaller radius than that of the normal region. As will be appreciated, when the cam / pointer mechanism 38 is rotated such that the alarm portion having the smallest radius contacts the roll 46c formed on the cantilever arm 46b of the key 46, the cantilever arm 46b is propelled away from the key body. 46a of switch 46, thereby activating switch 46. In response to this activation, appropriate steps, including but not limited to activation of an audio alarm, may be taken to signal that fluid in the container has reached a specific level.

According to the preferred embodiment of the invention, the cantilever arm is normally propelled away from the key body in a position in which the key is activated. The normal region of the cam surface holds the cantilevered arm of the key in a position relatively closer to the key body, ie in the non-activated position. The cam alarm region has a smaller radius such that the cantilever arm is allowed to return to its normal activated position. In another embodiment, keys may be used which are activated in the relative movement of the cantilever arm closer to the key body. When such switches are used, the normal region of the cam surface will have a smaller radius and the alarm region thereof will have a larger radius. Accordingly, the alarm region will move the cantilever arm relatively closer to the key body, thereby activating the key.

While only one key may be provided to signal both upper and lower fluid level limits, first and second keys are preferably provided with the first key used to indicate an upper fluid level limit and the second key used to indicate a limit. lower fluid level. As shown in the Figures, the keys 46 are preferably arranged in first and second key holders 48, 50, with each rotary key holder on an upper hub 52 having an axis of rotation coincident with the axis of rotation of the cam assembly. 38. The upper hub 52 is preferably axially spaced from the lower hub 36. A spring 54 is preferably disposed between the first support 48 and the second support 50 on the upper hub 52 and a nut 56 or similar fastener is used to secure the key holders 48, 50 and spring 54 in upper hub 52. The spring provides a biasing force against both the first and second key holders to generally hold these key holders in a fixed position. However, spring thrust can be overcome by moving the key holders closer to each other in an axial direction. With the thrust overcome, either or both of the key holders may be rotated about the axis of rotation with respect to the meter housing and / or with respect to each other.

As should be appreciated, turning the key holders 48, 50, and thus the keys 48 relative to the cam / pointer mechanism about the axis of rotation of the cam / pointer mechanism will change the movement range of the cam / pointer mechanism by which keys will not be activated. For example, when two keys are used, a first signaling a maximum fluid value and a second signaling a minimum fluid value, the keys may be moved further apart to reach a larger rotational area through which none of the keys are. enabled. Similarly, by moving the keys closer to each other, the keys are activated in response to a smaller rotational offset.

Furthermore, when the two keys are provided, the key holders are preferably configured to arrange the first and second keys to different axial positions. In this way, the key rollers contact the cam surface of the cam / pointer assembly to different axial regions. When two keys are provided in this manner, the cam surface preferably has two distinct cam portions, one associated with each of the two keys, with each portion including a distinct normal region and an alarm region, as described above.

A fixed point pointer is preferably associated with each of the fixed point keys 46. As shown in the figures, a first fixed point pointer 58 is arranged on the first key holder 48 and a second fixed point pointer 60 is arranged on the second one. key holder 50. Fixed point hands 58, 60 provide a visual indication of the position of pointer 38a of the cam / pointer mechanism 38 to which an associated key 46 will be activated. For example, when a switch 46 is provided for activation at a minimum fluid level, the fixed point pointer 58, 60 associated with that switch is arranged such that the cam assembly pointer 38a / pointer 38b will be in the same rotational position when The alarm region corresponding to the minimum fluid level activates the switch. Accordingly, a user can visually inspect the meter to determine if the fluid level in the container is reaching a fixed point, for example a maximum or minimum fluid level. The fixed point hands and the meat assembly pointer / pointer preferably are disposed in the cutout 31 of the cover 30. This cutout provides a viewing area for an observer. In addition, the dial is placed in the viewing region, radially internally of the fixed point hands and the cam / pointer mechanism pointer. In this way, the fixed point hands and the cam mechanism pointer / pointer move relative to the dial, providing a complete visual representation of both fixed points associated with the keys and a current fluid level.

The fixed point hands and cam mechanism pointer / pointer are movable within this range of view as described in detail above.

When keys 46 and corresponding key holders 48, 50, upper hub 52, and fixed point hands 58, 60 are provided, it is desirable to maintain accessibility to the lower hub, that is, to facilitate meter calibration in the manner described above. Accordingly, the upper hub 52 preferably has an opening 53 formed axially therein. In this way, a tool, such as a flat-head screwdriver, can be inserted through the meter cover and the upper hub to contact the opening formed on a top surface of the lower hub. As described above, the tool can be used to facilitate relative rotation of the cam / pointer assembly with respect to the lower hub and second magnet. Similarly, the cover 30 and any other axially arranged structure above the lower hub also has an opening along the lower hub axis to facilitate access to the opening formed in the lower hub.

The embodiments discussed above are representative of embodiments of the present invention and are provided for illustration only. Embodiments are not intended to limit the scope of the invention. Variations and modifications are apparent from a reading of the foregoing description and are included within the scope of the invention. The invention is intended to be limited only by the extent of the accompanying claims.

Claims (33)

1. Vertical fluid level meter for displaying a fluid level in a closed container, the meter comprising: a float portion disposed within the closed container and including a float and a first rotating member, the float portion converting a vertical float displacement caused by a fluid level change to a rotational displacement of the first rotating member; and a meter portion disposed on an exterior of the enclosed container and including a second pivot member, a pointer, and a clutch mechanism selectively engaging the pointer to the second pivot member, the meter portion being arranged with respect to the float portion such that the second pivot member is rotatably coupled to the first pivot member, wherein the clutch mechanism selectively engages (i) the pointer with the second pivot member such that the pointer pivots with the second pivot member to provide a visual indication of fluid level, and (ii) disengages the second rotating limb pointer to allow movement of the pointer with respect to the second rotating limb. Meter according to claim 1, characterized in that the meter portion further includes one or more fixed point switches activated when the fluid level reaches a predetermined level. Meter according to claim 2, characterized in that the pointer includes a cam surface having a normal region and an alarm region, the keys are arranged to contact the cam surface, and the keys are activated when the alarm region of the cam surface contacts the switches. Meter according to claim 3, characterized in that it further comprises one or more fixed point indicators, one corresponding to each of the keys, each indicator indicating a position of the pointer to which the alarm portion of the cam will activate. the respective key. Meter according to Claim 2, characterized in that the meter portion includes two keys, one of the two keys being activated when the fluid level in the container reaches a maximum fluid level and a second of the two keys being activated. activated when the fluid level in the container reaches a minimum fluid level. Meter according to Claim 1, characterized in that the clutch mechanism is a lock washer disposed between a clamp and the pointer, the lock washer providing a thrust force in an axial direction to engage the pointer with the clutch. second rotary mechanism. Meter according to Claim 6, characterized in that the second rotating member includes a first hub having an opening formed at a top thereof. Meter according to Claim 7, characterized in that the opening receives a tool which makes it easier to overcome the thrust force provided by the lock washer to disengage the first rotational member of the pointer. Meter according to claim 8, characterized in that it further comprises a second hub axially displaced from the first hub, the second hub having an opening formed axially therein to facilitate access to the opening in the first hub. Meter according to Claim 1, characterized in that the first rotating member includes a first magnet and the second rotating member includes a second magnet. 11. Vertical fluid level meter for measuring a fluid level in an enclosed space, the meter comprising: a rotational member having a rotational position corresponding to a vertical height of a float disposed in the enclosed space; a rotary mechanism in communication with the rotational member, the mechanism including a pointer indicating to an observer the rotational position of the rotary mechanism; a clutch member for propelling the rotary mechanism against the rotational member with sufficient pushing force to engage the rotary mechanism with the rotational member, thereby causing the rotary mechanism to rotate with the rotational member; and a relative movement facilitator disposed on at least one of the rotational member and the rotary mechanism to allow the thrust provided by the clutch member to be overcome, thereby disengaging the rotary mechanism of the rotational member to rotate the rotary mechanism with respect to the Rotational member. Meter according to Claim 11, characterized in that the rotary mechanism further includes a cam surface having first and second regions with different radii. Meter according to Claim 12, characterized in that the pointer and the cam surface are formed as an integral structure. Meter according to claim 12, characterized in that it further comprises one or more fixed point keys arranged to contact the cam surface of the rotary mechanism such that the keys are activated when in contact with one of the first and second portions of the rotary mechanism. cam surface, and switches are not activated when in contact with each other from the first and second portions. Meter according to claim 14, characterized in that it further comprises one or more fixed point indicators, one associated with each of one or more keys and providing a visual indication of the position of the cam surface to which the respective key will be. enabled. Meter according to Claim 14, characterized in that two fixed point keys are provided and the cam surface activates each key independently. Meter according to claim 16, characterized in that one of the two fixed-point switches is activated when the fluid level reaches a predetermined minimum level, and the second of the two fixed-point switches is activated when the level is reached. fluid reaches a predetermined maximum level. Meter according to Claim 16, characterized in that the keys are movable with respect to one another and with respect to a rotational axis of the rotary mechanism. Meter according to Claim 11, characterized in that the rotational member includes a first hub and the relative movement facilitator includes an opening formed in the first hub, the opening being sized to receive a tool to facilitate relative rotation of the mechanism. rotational with respect to the rotational member. Meter according to Claim 19, characterized in that it further comprises a second axially spaced hub of the first hub, the second hub having an axially formed opening therethrough which the tool can be passed to engage the opening formed in the first hub. cube. 21. Vertical fluid level meter for displaying a fluid level in a closed container, the meter comprising: a float portion disposed within the container and having a first magnet arranged near a top of the container, the first magnet rotating correspondingly to a change in fluid level in the container; a second magnet disposed outside the container and magnetically coupled to the first magnet such that the second magnet rotates correspondingly with the first magnet; a pointer mechanism providing a visual representation of the rotational position of the second magnet; and a clutch mechanism selectively engaging and disengaging the pointer mechanism with the second magnet such that the pointer mechanism rotates with and with respect to the second magnet, respectively. Meter according to Claim 21, characterized in that it further comprises one or more keys arranged next to the pointer mechanism and activatable by the pointer mechanism. Meter according to claim 22, characterized in that the pointer mechanism further includes a cam surface and the keys are arranged to contact the cam surface, the cam surface being configured to selectively activate one or more keys. Meter according to Claim 22, characterized in that it further comprises one or more key hands, one associated with each of one or more keys, and providing a visual indication of the position at which the at least one key will be activated. . Meter according to Claim 22, characterized in that the one or more keys are adjustable with respect to the pointer mechanism. Meter according to Claim 21, characterized in that the clutch mechanism includes a lock washer disposed between a fastener and the pointer mechanism, the lock washer providing an axial force to engage the pointer mechanism with the second one. magnet, the pointer mechanism being disengaged from the second magnet overcoming axial force. Meter according to claim 26, characterized in that it further comprises a first hub attached to the second magnet, the first hub including an opening formed therein to receive a tool retaining the second stationary magnet while the pointer mechanism can be rotated. manually to overcome axial force to disengage the second magnet pointer mechanism. Meter according to claim 27, characterized in that it further comprises a second hub axially displaced from the first hub opposite the first and second magnets, the second hub having an opening formed axially therein providing access to the opening formed in the first hub. 29. Electricity transformer characterized by having an external indication of the fluid level within the transformer including: a closed container; a transformer disposed within the container; dielectric fluid within the container at least partially covering the transformer; a float inside the container contacting the dielectric fluid and translating substantially vertically into the container with a change at the dielectric fluid level; a first rotatable member disposed near a top of the container; a linear motion coupler for rotational motion connected between the float and the first rotating member that rotates the first rotating member in response to a vertical float translation; a second rotating member outside the container and coupled to the first rotating member; an indicator meter out of the container; and a clutch connected between the second rotating member and the indicator gauge. Electrical transformer according to claim 29, characterized in that the indicator meter includes a pointer mechanism indicating the rotational position of the second rotating member. An electrical power transformer according to claim 30, further comprising one or more keys, the pointer mechanism having a cam surface formed therein to communicate with the keys to selectively activate the keys. Power transformer according to claim 29, characterized in that the clutch includes a lock washer and a clamp pushing the lock washer and indicator gauge to the second rotating member. Electrical transformer according to claim 29, characterized in that the second rotating member comprises a groove formed on a top of it to receive a tool that facilitates, together with the clutch, engagement and disengagement of the indicator meter and the second rotating limb.