Disconnect switch with a detent mechanism to protect against over-rotation

An electrical disconnect switch including an over-rotation protective feature to protect the load switch from damage is disclosed. The electrical disconnect switch may include an enclosure, a load switch, and a handle assembly coupled to the load switch. The disconnect switch may include a detent between the handle assembly and the load switch so that during excessive rotation or torqueing the handle assembly is permitted to decouple or break-away from the load switch to prevent excessive stress from being transferred to the load switch and thus prevent any damage to the load switch.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to electrical disconnect switches, and more particularly to an electrical disconnect switch incorporating a detent mechanism to protect the disconnect switch and/or the load switch from damage caused by, for example, over-rotation of the handle assembly.

BACKGROUND OF THE DISCLOSURE

Electrical switches such as, for example, disconnect switches, mechanical interlocks, rotatably actuatable switches, etc. (collectively referred to herein as an electrical disconnect switch) are used in a variety of commercial applications, both indoors and outdoors, for energizing and de-energizing electrical devices, such as machinery, motors, lights, fans, pumps, generators and the like.

Generally speaking, referring toFIGS. 1 and 2, an electrical disconnect switch10may include an external handle assembly50connected to an electrical load switch75located within an electrical enclosure20. In use, the enclosure20may include a body portion22and a door24. The door24may be pivotably coupled to the body portion22by hinges26for opening and closing the door24to provide access to an interior portion of the enclosure20. The door24may be pivotably coupled to the body portion22of the enclosure20along any wall thereof, for example, to a side wall of the body portion22as illustrated inFIG. 2, or along a bottom wall of the body portion22as illustrated inFIG. 1. Additionally, the enclosure20may include one or more fasteners30for securing the door24to the body portion22.

Referring toFIG. 2, the electrical disconnect switch10includes an electrical load switch75mounted in an interior of the enclosure20. The electrical disconnect switch10may also include a number of other electrical components as well such as, for example, fuses, relays, contactors, etc. As will be appreciated by one of ordinary skill in the art, the electrical disconnect switch10receives power through a plurality of power input lines27and supplies power to an associated electrical device via a plurality of output lines28. The handle assembly50(FIG. 1) on the front of the door24is coupled (interlocked) to the load switch75through, for example, a shaft90(FIG. 3) to operate the actuating mechanism of the load switch75. That is, referring toFIG. 3, the load switch75may be equipped with a switch shaft76having a lateral pin78disposed at a distal end80thereof. The distal end80of the switch shaft76may be received within a recess92formed in the shaft90to rotationally lock the shaft90to the switch shaft76. Thus arranged, rotational movement of the handle assembly50causes the shaft90to rotate, which in turn rotates the switch shaft76via the pin/slot interaction.

In use, as will be appreciated by one of ordinary skill in the art, a load associated with the load switch75can be energized or de-energized, depending on the direction of rotation of the handle assembly50. That is, the electrical disconnect switch10is “ON” (e.g., supplying power to the associated electrical device) when the door24of the enclosure20is closed and the handle assembly50is in an “ON” position. When the handle assembly50is moved to an “OFF” position, the actuating mechanism of the load switch75will have been moved to open the contacts, so that power to the associated electrical device is disconnected. Generally speaking, the handle assembly50is rotated ninety-degrees to transition the electrical disconnect switch between the ON and OFF positions. This is a simplified explanation of the operation of the electrical disconnect switch10for purposes of the present disclosure. The electrical disconnect switches illustrated and described herein are provided for background information. The present disclosure has wide applicability and should not be limited to any particular electrical disconnect switch unless specifically claimed.

As will be appreciated, electrical disconnect switches10find wide industrial application, and thus they may be employed in a variety of harsh environments such as, for example, rain (for outdoor applications), water spray (for indoor applications in which a hygienic work space is required), dust, etc. Additionally, electrical disconnect switches10may be operated in tough working conditions and thus may be subject to high stresses. For example, during an emergency, the electrical disconnect switch10may be operated to disconnect electrical power to the associated electrical device. As a result, electrical disconnect switches10may be subject to damage by, for example, over-rotation of the handle assembly50. Accordingly, it would be desirable to provide an electrical disconnect switch with an improved mechanism to protect against damage caused by over-rotation.

SUMMARY OF THE DISCLOSURE

Disclosed herein is an electrical disconnect switch. In various embodiments, the electrical disconnect switch includes an enclosure having a front surface and an interior portion. The enclosure may include a load switch disposed within the interior portion, the load switch being rotatable between an ON position and an OFF position, and a handle assembly including a rotatable handle and a shaft, the shaft being arranged and configured to selectively couple the rotatable handle to the load switch, the rotatable handle being accessible via the front surface. The shaft includes a detent, the detent being arranged and configured to enable the rotatable handle to be selectively decoupled from the load switch upon application of a predetermined amount of force.

In one embodiment, the load switch is operatively coupled to a switch shaft, the switch shaft including a cap at a distal end of the switch shaft. The cap and the shaft being coupled to each other via the detent such that application of the predetermined amount of force causes the shaft to decouple from the cap.

In one embodiment, the detent includes a spring plunger. The spring plunger being positioned in one of the shaft and the cap, the other one of the shaft and the cap includes a recess for receiving an end portion of the spring plunger. The spring plunger may include a body portion, a plunger element, and a spring for biasing the plunger element away from the body portion and into contact with the recess. In use, application of the predetermined amount of force causes the plunger element to decouple from the recess so that the handle assembly can freely rotate until the plunger element re-engages the recess.

In one embodiment, the detent may be an axial detent extending from a front surface of one of the shaft and the cap. The other one of the shaft and the cap includes a recess for receiving at least a portion of the axial detent. The shaft may include a spring for biasing the shaft towards the cap. In use, application of the predetermined amount of force over-rides the biasing force supplied by the spring causing the shaft and the cap to decouple from each other.

In one embodiment, the detent includes a spring. The shaft may include a recess formed in a front face thereof for receiving a portion of the cap therein. The shaft may further include a groove formed in an inner surface of the recess for receiving the spring. The cap may include a recess for receiving a portion of the spring. The spring may include a first end, a second end, and an intermediate portion positioned between the first and second ends, the intermediate portion include a bulge for operatively engaging the recess formed in the cap. In use, application of the predetermined amount of force causes the bulge formed in the intermediate portion of the spring to deflect to decouple the spring from the recess.

DETAILED DESCRIPTION

Numerous embodiments of an over-rotation protective feature for use with an electrical disconnect switch in accordance with the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are presented. As will be described and illustrated, in some embodiments, the electrical disconnect switch may include a detent or a detent mechanism (used interchangeably herein without the intent to limit) located between the handle assembly located externally of the enclosure and the load switch located within the enclosure so that during excessive rotation or torqueing the handle assembly is permitted to decouple or break-away from the load switch to prevent excessive stress from being transferred to the load switch and thus prevent any damage to the load switch. In one embodiment, excessive stress or application of a predetermined amount of force may substantially correspond to an amount of stress associated with damage to the load switch. The over-rotation feature of the present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain example aspects of the over-rotation feature to those skilled in the art. In the drawings, like numbers refer to like elements throughout unless otherwise noted.

As will be described in greater detail below, in various embodiments, an electrical disconnect switch according to the present disclosure may include one or more over-rotation features to prevent damage to the electrical disconnect switch due to over-rotation of the handle assembly. That is, for example, according to the present disclosure, an electrical disconnect switch may incorporate an over-rotation feature to protect the load switch75located within the enclosure20of the electrical disconnect switch10from over-rotation, for example, rotation beyond the ON/OFF positions, which may damage the load switch75. That is, in some embodiments, the over-rotation feature of the present disclosure provides one or more mechanisms to prevent excessive stress or application of force exceeding a predetermined amount of force (e.g., to prevent stress levels or forces associated with damage to the load switch) caused by over-rotation of the handle assembly50from being transferred to the load switch75.

As will be described herein, the over-rotation feature according to the present disclosure may be used with any suitable electrical disconnect switch now known or hereafter developed. As such, details regarding construction, operation, etc. of the electrical disconnect switch are omitted for sake of brevity of the present disclosure. In this regard, it should be understood that the present disclosure should not be limited to the details of the electrical disconnect switch disclosed and illustrated herein unless specifically claimed and that any suitable electrical disconnect switch can be used in connection with the principles of the present disclosure.

The over-rotation feature according to the present disclosure may be any suitable over-rotation feature now known or hereafter developed including, for example, a detent mechanism, a slip-clutch assembly, or the like. Additionally, the over-rotation feature may be positioned anywhere in the electrical disconnect switch10between the handle assembly50and the load switch75. In this manner, the over-rotation feature enables the handle assembly50to connect to the load switch75while also enabling the handle assembly50to decouple, disconnect, break-away, or the like from the load switch75if the handle assembly50is over-rotated or subject to excessive torque, which may damage the load switch75. That is, once the load switch75is actuated as required, continued rotation or excessive torqueing of the handle assembly50will cause the handle assembly50to decouple from the load switch75to prevent damage to the load switch75. In some embodiments, the over-rotation feature is re-settable such that, once it has broken away, the over-rotation feature can be automatically reset by continued rotation and re-engagement of the over-rotation feature (e.g., detent mechanism).

Referring toFIGS. 4A and 4B, in one illustrative, example embodiment, the over-rotation feature may be in the form of a multi-piece shaft incorporating a detent mechanism. That is, as illustrated in the example embodiment, the switch shaft76(FIG. 3) may be operatively coupled to a cap110, for example, the distal end80of the switch shaft76may be operatively coupled to the cap110. A spring112may be provided for biasing the cap110towards the shaft190. The spring112may be a wave spring, a conical flat spring, a disk spring, a Belleville washer, although other types of springs and/or biasing members are envisioned. In use, the spring112may be constrained or restrained by, for example, a snap ring114or the like. Additionally, the shaft190may incorporate a detent mechanism120for interacting with the cap110, which is operatively coupled to the load switch75via the switch shaft76. In use, over-rotation or excessive torque transmitted from the handle assembly50causes the shaft190to decouple from the cap110so that any excessive rotation or torque applied to the handle assembly50is prevented from transferring to the load switch75.

As illustratively shown inFIGS. 4A-4D, in one example embodiment, the detent mechanism120may be in the form of a spring biased plunger130. The spring biased plunger130may include a body portion132, a plunger element134and a spring136for biasing the plunger element134away from the body portion132. For example, as illustrated inFIGS. 4A and 4B, the spring biased plunger130may be positioned within a cavity formed in the shaft190, the plunger element134being biased by the spring136away from the body portion132and towards the cap110. Alternatively, as illustrated inFIG. 4C, the spring biased plunger130may be positioned within a cavity formed in the cap110, the plunger element134being biased by the spring136toward a front surface191of the shaft190. As will be appreciated by one of ordinary skill in the art, the spring plunger130may be any commercially available, off-the-shelf spring plunger.

Referring toFIGS. 4A and 4B, in one illustrated embodiment, in use, the body portion132of the spring plunger130may be positioned within a cavity formed in the shaft190such that the plunger element134extends axially from a front surface191of the shaft190. Additionally, the cap110may include a recess or partial borehole140for interacting with (e.g., partially receiving) the plunger element134. In use, with the plunger element134residing in the recess140formed in the cap110, rotation of the handle assembly50is transmitted to the load switch75. However, if excessive rotation or torque is applied to the handle assembly50, the plunger element134will decouple from the recess140thus preventing rotation from the shaft190, which is associated with the handle assembly50, from being transmitted to the cap110, which is associated with the load switch75. That is, in one embodiment, over-rotation (e.g., motion exceeding 90 degrees) or excessive torque applied to the handle assembly50will cause the shaft190to release or slip relative to the cap110. For example, with the handle assembly50in the ON position, a user may rotate the handle assembly50by, for example, ninety degrees to the OFF position to terminate electrical power being transferred to the associated electrical device. In use, however, the user may over-rotate or apply excessive torque to the handle assembly50beyond that required to move the handle assembly50from the ON position to the OFF position. In such situation, the detent mechanism120(e.g., spring plunger130) may decouple the handle assembly50from the load switch75, and more specifically, may decouple the shaft190from the cap110, to protect the load switch75.

Thereafter, the handle assembly50can rotate (e.g., freely spin), for example, 360 degrees if rotated in the same direction or less if rotated in the opposite direction, by slipping until the plunger element134finds the recess140again. In this manner, with the detent (e.g., plunger element134) positioned within the recess140, the handle assembly50will be re-settable and will always be properly positioned relative to the load switch75. In this manner, the detent mechanism120is automatically resettable simply by continuing to rotate the handle assembly50.

Referring toFIGS. 4A-4D, the detent mechanism120(e.g., spring plunger130) may be positioned in any of a variety of locations and/or orientations relative to the shaft190and cap110. For example, as illustrated inFIGS. 4A and 4B, and as previously described, the body portion132of the spring plunger130may be positioned within a cavity formed in the shaft190such that the plunger element134extends axially from a front surface191of the shaft190and the recess140may be formed in a front surface141of the cap110. Alternatively, as illustrated inFIG. 4C, the body portion132of the spring plunger130may be positioned within a cavity formed in the cap110such that the plunger element134extends axially from the front surface141of the cap110and the recess140may be formed in the front surface191of the shaft190. Alternatively, as illustrated inFIG. 4D, the spring plunger130may be positioned so that the plunger element134extends from a side surface193of the shaft190and the recess140may be formed in a side surface142of the cap110, or vice-versa.

Moreover, while the detent mechanism120has been described as being in the form of a spring plunger130, the detent mechanism120can be any suitable mechanism now known or hereafter developed. For example, referring toFIGS. 5A and 5B, the detent mechanism120may be in the form of an axial detent or pawl. That is, as illustrated, the shaft190may include an axial detent or pawl150for contacting a surface formed in a recess152of the cap110. In addition, the shaft190may include a spring154such as, for example, a wave spring, a conical flat spring, a disk spring, a Belleville washer, or the like, for biasing the cap110towards the shaft190. In use, rotation of the handle assembly50is transmitted from the shaft190to the cap110to the switch shaft76and to the load switch75. However, during an over-rotation or excessive torqueing situation, the excessive load caused by over-rotation or torqueing will over-ride the biasing force supplied by the spring154causing the shaft190to pull away from the cap110until the excessive force is removed. In this manner, during excessive rotation or torque, the associated excessive stress causes the shaft190to decouple from the cap110.

Referring toFIG. 5B, in use, the axial detent or pawl150may have a trapezoidal shape for receipt within a corresponding trapezoidal recess, although other shapes are envisioned.

Alternatively, referring toFIGS. 6A and 6B, the detent mechanism120may be in the form of a spring element180. That is, in accordance with the present embodiment, the shaft290may include a recess292formed in a front surface291thereof for receiving the cap110, which is operatively coupled with the switch shaft76. As such, in connection with the embodiment ofFIGS. 6A and 6B, the cap110is adapted and configured for positioning within the shaft290. In addition, the shaft290may include a partial groove182formed in an inner surface of the recess292for receiving the spring180. In use, the cap110may include a groove or recess192for receiving a portion of the spring180so that, during normal operation of the device, rotation of the handle assembly50is transmitted from the shaft290to the cap110via the interaction between the spring180located in the switch290and the groove192formed in the cap110. Alternatively, it is envisioned that the spring180may be positioned in the cap110and the groove192may be formed in the switch290.

Referring toFIG. 6C, the spring180may include a first end184, a second end186, and intermediate portion188positioned therebetween. The intermediate portion188may include a bend or bulge189for operatively engaging the corresponding groove192formed in the cap110.

In use, with the bulge189of the spring180residing in the groove192formed in the cap110, rotation of the handle assembly50is transmitted to the load switch75. However, if excessive rotation or torque is applied to the handle assembly50, the spring180, and more specifically, the bulge189formed in the intermediate portion188of the spring180, will deflect inwards causing the spring180to flatten out, deflect, move into, or the like, the partial groove182formed in the inner surface of the recess292of the shaft290causing the bulge189to decouple from the groove192thus preventing rotation from the handle assembly50to the load switch75. Thereafter, the handle assembly50can rotate (e.g., freely spin), for example, 360 degrees if rotated in the same direction or less if rotated in the opposite direction, by slipping until the bulge189formed in the intermediate portion188of the spring180finds the groove192again. In this manner, with the detent (e.g., bulge189formed in the intermediate portion188of the spring180) positioned within the groove192, the handle assembly50will always be properly positioned relative to the load switch75. That is, the detent (e.g., bulge189formed in the intermediate portion188of the spring180) is automatically re-settable such that, once it has broken away, the detent can reset itself by continued rotation and re-engagement of the detent with the groove192.

In use, as previously mentioned, regardless of the configuration of the detent being used, the detent preferably is adapted and configured to engage a single corresponding groove or recess so that in use, once the detent is properly positioned within the groove or recess, the handle assembly50is always properly positioned relative to the load switch75, although it is envisioned that in certain situations, it may be beneficial to include more than one corresponding groove or recess. That is, by providing a single recess or location for receiving the detent, the handle assembly50always finds its proper location upon continued or return rotation.

Additionally, in some embodiments, the detent is configured so that a calculated force achieves a predetermined break-out torque. In this manner, the user can easily rotate the handle assembly50under normal operating conditions without worrying about the handle assembly50decoupling from the load switch75. It is only when excessive forces are applied due to over-rotation or over-torqueing that the handle assembly50is decoupled from the load switch75. Thus, in some embodiments the detent mechanism is configured to transmit rotational loads associated with typical actuation forces of an electrical switch. The detent mechanism may also be configured to decouple associated sections of the switching mechanism when subjected to rotational forces that are a predetermined amount below a failure load of the load switch.

The disconnect switch may be provided in any required size and/or rating. For example, the disconnect switch may be provided with ratings of 60 amps, 30 amps and smaller. Alternatively, the disconnect switch may be provided in larger amps.

While the present disclosure refers to certain embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claim(s). Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these embodiments. In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.

The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.

The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. The terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., engaged, attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative to movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. All rotational references describe relative movement between the various elements. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative to sizes reflected in the drawings attached hereto may vary.