Universal switch restraint device

A universal restraint device for a switch handle includes a channel adapted to accommodate the switch handle. The channel includes a base wall, first and second side walls that extend generally perpendicularly from the base wall, and first and second feet that extend toward one another from distal ends of the first and second side walls. The channel includes a width defined by a distance measured between the first and second side walls. A lever arm extends from the base wall a distance greater than the width of the channel.

FIELD OF INVENTION

The present invention relates to the field of electrical systems and repairs thereof. In particular, the present invention relates to a device that can be secured to a switch handle to inhibit the handle from moving relative to the switch.

BACKGROUND OF THE INVENTION

In some circumstances it may be necessary to restrain a switch from being turned on or off. For example, rules promulgated by the Occupational Safety and Health Administration (OHSA) require a circuit breaker to be “locked-out,” i.e., restrained from being switched from an off position to an on position, for safety purposes to allow an individual to repair or install electrical equipment powered via the circuit breaker.

Manufacturers of circuit breakers have developed a variety of devices for restraining individual circuit breaker switches. One such device disclosed in U.S. Pat. No. 4,347,412 is illustrated herein inFIG. 1. An inclined groove52extends into a surface54of the restraint device50at an angle56and accommodates a switch handle58. When the restraint device50is mounted on the switch handle58the inclined groove52engages the switch handle58and the surface54engages a surface60of a switch housing62, thereby inhibiting the switch handle58from moving relative to the switch housing62.

Manufacturers may design the housing and switch handle of a circuit breaker switch such that only their respective restraint devices can interface therewith. For example, the housing may have a lip, groove, or ridge at a fixed distance from the switch handle such that the manufacturer's restraint device may be compatible with the circuit breaker switch, but restraint devices produced by competing manufacturers may not. A risk exists that an individual may place an incompatible restraint device on a circuit breaker resulting in failure of the restraint device and potential injury to the individual. Another problem with available switch restraint devices is their bulkiness. U.S. Pat. Nos. 5,079,390 and 5,147,991 each disclose a circuit breaker restraint device having a member whose width is equal to that of a switch handle. The large size of these restraint devices requires a significant amount of material and raises the cost of the restraint device. A need, therefore, exists for a universal switch restraint device that can be used without modification with a multiplicity of brands of circuit breakers.

SUMMARY OF THE INVENTION

In one aspect of the invention, a universal restraint device for a switch handle that projects through an aperture in a switch housing is presented. The universal restraint device comprises a collar member forming a channel therethrough and adapted to engage the switch handle. A blocking member extends from the collar member and is configured to contact the switch housing external to the aperture when the collar member engages the switch handle.

In another aspect of the invention, a universal restraint device for a switch handle is presented. The universal restraint device comprises a channel adapted to accommodate the switch handle and having first and second planar ends. A lever arm extends from the channel a distance greater than the greatest dimension measured transversely across the channel.

In a further aspect of the invention, a universal restraint device for a switch handle is presented. The universal restraint device comprises a channel adapted to accommodate the switch handle. The channel includes a base wall, first and second side walls that extend generally perpendicularly from the base wall, and first and second feet that extend toward one another from distal ends of the first and second side walls. The channel includes a width defined by a distance measured between the first and second side walls. A lever arm extends from the base wall a distance greater than the width of the channel.

Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description, wherein similar structures have similar reference numerals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 2 and 10, in one embodiment of the present invention, a universal restraint device70engages an electrical switch72that includes a switch housing74and a switch handle76. The switch handle76extends through an aperture78(FIGS. 8 and 10) disposed through a switch panel80on a side of the switch housing74. The switch panel80may have any shape as known in the art, for example, the switch panel80may have a generally rectangular planar shape, as illustrated inFIGS. 2 and 8. In operation, the electrical switch72may be inserted into a circuit breaker board (not shown) such that only the switch panel80is exposed. The switch handle76is adapted to be moved by a user between ON and OFF positions (seeFIG. 8). As illustrated inFIG. 10, the switch handle76in either the ON or OFF positions may form an acute angle82with the switch panel80. Movement of the switch handle76between the ON and OFF positions may consist of either rotation and/or translation relative to the switch housing74.

Referring now toFIGS. 2-7and10, the universal restraint device70includes a collar member82adapted to receive the switch handle76such that it substantially or wholly surrounds at least a portion of the switch handle76when deployed. The universal restraint device70further includes a blocking member or lever arm84attached to the collar member82. The blocking member84may be integral with the collar member82or may be manufactured as a separate component and subsequently attached to the collar member82using any common method of attachment as known in the art, including, without limitation, by welding or use of fasteners directly connecting the two components, one to the other, or indirectly by attachment of each to a single bracket. The universal restraint device70may be manufactured from any suitable material conventionally used to make fasteners, such as, without limitation intended, steel, stainless steel, copper, aluminum alloy, polyethylene, polyvinyl chloride, and polypropylene. A non-conducting material may be used to form the universal restraint device70in order to reduce the risk of electrical shock. The material usefully employed for the fasteners is suitable to the extent that it exhibits similar integrity and strength as are associated with the above-identified materials.

Referring toFIGS. 5 and 7, the collar member82defines a passage or channel86through which the switch handle76protrudes when the universal restraint device70engages the electrical switch72. The collar member82may surround the perimeter of the switch handle76wholly (not shown) or leave a portion of the surface88of the switch handle76exposed as shown inFIGS. 2 and 10. Yet further alternative embodiments of the collar member82expose additional amounts of the perimeter of the switch handle76on one of more sides thereof.

Referring toFIGS. 4 and 6, in another embodiment of a universal restraint device70a, all of one side face of the switch handle76is exposed, thereby allowing such an embodiment to be usefully employed with switch handles having any width that may extend through the uncovered portion of the switch handle. For example, as illustrated inFIGS. 4 and 6, the universal restraint device70aincludes a collar member82athat defines a channel86aand that does not cover or contact the switch handle76on its lateral surface116(SeeFIGS. 2 and 8) upon engagement with the switch handle76. Once the universal restraint device70ais secured to the switch handle76by means, for example, of fastener124, then the switch handle76is impeded from switching from whichever position it was in to its opposite position.

Referring toFIGS. 5 and 7, the channel86of the collar member82is defined by a base wall90, first and second side walls92,94that extend generally perpendicularly from the base wall90, and first and second feet96,98that extend toward one another from distal ends of the first and second side walls92,94, respectively. The channel86of the collar member82is dimensioned such that any conventional switch handle76may extend through the channel86. In addition, gap100between distal ends of the first and second feet96,98allows the channel86to be flexibly adjustable. When the universal restraint device70engages the switch handle76, interior surfaces102of the first and second feet96,98abut a surface104(SeeFIGS. 2 and 10) of the switch handle76.

Referring toFIG. 6, the channel86aof the collar member82ais defined by the base wall90, a side wall94athat extends generally perpendicularly from the base wall90, and a top wall98athat extends generally perpendicularly from a distal end of the side wall94a.

The channel86,86aincludes first and second ends106,108that are each generally planar, as illustrated inFIGS. 3 and 4. In one embodiment, the blocking member84extends from the base wall90substantially parallel to the first end106of the channel86,86a.

The channel86of the collar member82may be dimensioned to form a press fit with the switch handle76. For example, the surfaces102and an interior surface110of the base wall90of the collar member82may be in flush contact with the surfaces104and88of the switch handle76, respectively, and/or interior surfaces112,114of the side walls92,94may be in flush contact with lateral surfaces116of the switch handle76. Similarly, the channel86aof the collar member82amay be dimensioned to form a press fit with the switch handle76via flush contact between the surfaces88and110and between the surface104and an interior surface102aof the top wall98a.

Referring toFIGS. 2-7, the blocking member84includes a contact surface118that is adapted to make substantial contact with the switch panel80external to the aperture78. Accordingly, the contact surface118may be substantially planar and may have any shape as desired, for example, rectangular as illustrated inFIGS. 5 and 6. The surface118is generally parallel to the switch panel80when the universal restraint device70,70aengages the electrical switch72.

The blocking member84extends away from the collar member82,82agenerally in the direction of motion of the switch handle76that the universal restraint device70,70ais configured to prevent. The blocking member84has a long dimension or length, L, measured between a proximal end120attached to the base wall90and a distal end122of the blocking member84. The channel86has a greatest internal dimension measured transversely across the channel86between opposite internal surfaces thereof. For example, the greatest transverse internal dimension of the channel86may be a width, W, measured between the interior surfaces112,114of the side walls92,94, as illustrated inFIGS. 5 and 7. Similarly, the channel86amay, for example, have a greatest internal dimension, W′, measured transversely across the channel86abetween the surface110and the interior surface102aof the top wall98a, as illustrated inFIG. 6.

The length L of the blocking member84is configured to be a length greater than the greatest transverse internal dimension W, W′ of the channel86,86a, respectively. This configuration provides a blocking member sufficiently long to make contact with the switch panel80exterior to the aperture78so long as the channel86,86afits over the switch handle76. Furthermore, more contact between the blocking member84and the switch panel80may increase friction therebetween and prevent slippage of the universal restraint device70,70arelative to the electrical switch72.

The blocking member84has a short dimension, S, measured transverse to the long dimension L. The short dimension, S, may be configured to be less than the greatest transverse internal dimension of the channel86,86a, as illustrated inFIGS. 5-7. This configuration may be useful in application of multiple universal restraint devices70,70ato multiple electrical switches72that are arranged next to one another within a confined space.

In other embodiments, in addition to or instead of being configured substantially parallel to the first end106, the blocking member84may form an angle with the first end106. An angled blocking member84may be useful in some circumstances given the geometry and/or contours of the switch housing74, which may vary between brands of electrical switches72.

Not wishing to be bound by theory, the blocking member84acts as a lever arm that provides a reaction moment in response to rotational movement of the switch handle76. Any force applied to move the switch handle76from the ON position to the OFF position (or vice versa depending on the configuration of the universal restraint device70,70aand switch handle76) causes the switch panel80to produce an equal and opposite reaction force in the blocking member84that substantially eliminates movement of the switch handle76. The blocking member84transfers this reaction force to the switch handle76via the collar member82,82a, which operatively grips the switch handle76when a force is applied to move the switch handle76.

The interior surface110of the base wall90may contact the surface88of the switch handle76. The interior surface110may be positionally adjustable such that an interior dimension measured between the interior surface110and surfaces102may be altered to allow the collar member82,82ato be able to universally grip a variety of switch handles76having a variety of shapes and sizes.

Alternatively, an adjustable fastener124, such as, for example, a set screw, may extend through a threaded aperture126disposed through the base wall90and impinge the surface88of the switch handle76. The distance that the fastener124extends into the channel86,86amay be adjusted by rotating the fastener124through the threaded hole126. The fastener124creates friction between the collar member82,82aand the switch handle76to increase the effectiveness of the grip there between. Additionally, the fastener124transfers the hereinabove described reaction force produced in the blocking member84to the surface88of the switch handle76thereby inhibiting movement of the switch handle76.

The adjustability of the fastener124allows the universal restraint device70,70ato be operational with a multiplicity of available brands of electrical switches72having a switch handle76as large as the maximum size of the channel86,86a. The fastener124may be fixed in a predetermined position relative to the collar member82,82aby a locking mechanism as described in U.S. Pat. Nos. 5,079,390 and 5,147,991, which are hereby incorporated by reference in their entireties.

Referring toFIG. 9, another embodiment of a universal restraint device140includes a shim128that may be inserted between the interior surface110of the base wall90and the surface88of the switch handle76. The shim128, like the fastener124, helps keep the collar member82engaged with the switch handle76and transfers the hereinabove described reaction force produced in the blocking member84to the surface88of the switch handle76. The shim128may be manufactured from an elastic material such that any deformation caused in the shim128by inserting the shim128between the switch handle76and the collar member82may be recovered. Suitable materials for the shim128may be plastic and/or rubber. The shim128may be attached to the universal restraint device140by a strap130. A further embodiment of a universal restraint device (not shown) includes the shim128attached to the collar member82a.

The adjustability of the universal restraint device70,70a,140not only allows for utility on a wide range of switch handle shapes and sizes but also allows a user to quickly and simply restrain an electrical switch from being actuated. This flexibility and ease of installation may save time in comparison to more complex devices intended only for tamper proof or more permanent installation. The universal restraint device70,70a,140described hereinabove may require less material to manufacture than known larger and bulkier restraint devices, thereby providing an economical benefit in cost of material. Further, the open nature of the second end108of the channel86,86aallows a user to see indicia such as brand, model, or amperage rating that may be printed or embossed on a distal end of the switch handle76.

While the present invention may be embodied in many forms, multiple embodiments are discussed herein with the understanding that embodiments illustrated are to be considered only as an exemplification of the invention and are not intended to limit the disclosure to the embodiments illustrated. For example, although the universal restraint device70,70a,140is described hereinabove with regard to a circuit breaker switch, the universal restraint device70,70a,140is also operable with wall mounted light switches. Further, it should be understood that the universal restraint device70,70a,140is not limited to use with electrical switches. The universal restraint device70,70a,140can be dimensioned to operate with any manual switch adapted to be selectively displaced in an ON or OFF position. It should be understood that the universal restraint device70,70a,140can engage a switch in both an upright and inverted position to prevent downward and upward movement, respectively, of the switch handle76.

INDUSTRIAL APPLICABILITY

A universal restraint device for a switch handle is presented that includes an adjustable collar member and a lever arm that is sized to be longer than a maximum internal transverse dimension of the collar member. The configuration and length of the lever arm and the adjustable size of the collar member allow the universal restraint device to be quickly and easily applied to a variety of switch handle shapes and sizes.

Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved. All patents, patent publications and applications, and other references cited herein are incorporated by reference herein in their entirety