Circuit Breaker Having Integral Cover/Handle Assembly

This invention relates to circuit breakers and in particular to the handle mechanisms used to manually open and close the circuit breaker.

Typically a handle which is removably connected to the operating mechanism is provided for manual operation of the circuit breaker. The handle projects through an opening provided in the removable cover of the circuit breaker. The cover and handle assembly are removable in order to facilitate maintenance or inspection of the internal components of the circuit breaker. One problem encountered by having these two pieces being removable is that the handle tends to slip from the cover and can become lost or broken. Thus, it would be advantageous to have an integral cover handle assembly where the handle mechanism is attached to the cover yet capable of still being used for manual operation of the circuit breaker.

The present invention is embodied by a handle assembly for manually controlling the operating mechanism of a circuit breaker. The handle assembly includes a base segment and a cap segment with the base segment being removably engaged with the operating mechanism of the circuit breaker. Positioned exterior to an opening provided in the cover of the circuit breaker housing is the cap segment. This segment engages with the base segment such that the handle is attached to the cover while being movable in the opening thereof during the transfer of the circuit breaker between the open and closed positions. The base segment can include an apron portion which extends out from the base segment such that the opening in the cover is closed as the handle assembly travels between the open and closed positions during operation of the circuit breaker. The apron is in close movable engagement with the cover in order to prevent the insertion of foreign objects into the internal workings of the circuit breaker.

In an alternate embodiment the operating mechanism of the circuit breaker can be provided with a tang projecting therefrom with the base segment having a bore therein for receiving and engaging this tang in a loosely fitting manner. The shape of the bore and the base segment of the handle is such that the tang remains in engagement with the base segment while allowing the handle to follow a line of motion which differs from the line of motion followed by the tang of the operating mechanism. Because the tang is loosely fitting inside the bore of the base segment, this facilitates mounting of the cover handle assembly onto the operating mechanism of the circuit breaker. In addition, this allows the handle to travel through a longer operating distance than the mechanism thus facilitating the differentiation between the on and off positions of the circuit breaker. Preferably, the cap and base segment are provided with locking edges to facilitate the mounting of the cap segment onto the base segment of the handle. By fabricating the cap from a material having some resilient qualities such as nylon, the cap assembly may be snapped onto the base segment thus eliminating the need for any tools or other fasteners for engaging the cap and base segments together.

For a better understanding of the invention, reference may be made to the embodiments exemplary of the invention shown in the accompanying drawings wherein:

FIG. 1 is a front view of the circuit breaker embodying the present invention;

FIG. 2 is a sectional view of the circuit breaker shown in FIG. 1 taken along line II--II;

FIG. 3 is a front elevational view of the base segment of the handle mechanism;

FIG. 4 is a side elevational view of the base segment of the handle mechanism;

FIG. 5 is a top view of the base segment of the handle mechanism;

FIG. 6 is a front elevational view of the cap segment of the handle mechanism;

FIG. 7 is a side elevational view of the cap segment of the handle mechanism; and

FIG. 8 is a top view of the cap segment of the handle mechanism.

Referring to FIGS. 1 and 2, the circuit breaker 10 embodying the present invention comprises a stationary contact 12 for conducting current, and a movable contact 14 for conducting current with the movable contact 14 operable between an open position and a closed position with respect to the stationary contact. An operating mechanism generally indicated at 16 consisting of springs, linkages, and pivots is used to transfer the movable contact 14 between the open and closed positions. A housing 18 including a removable cover 20 is provided for enclosing and electrically insulating the stationary contact 12, the movable contact 14 and the operating mechanism 16. Screws 22 or other fasteners are used to secure the cover 20 to the remainder of the housing 18. Terminals 24 for connecting current carrying conductors to the stationary and movable contacts are provided in the housing 18.

Referring to FIGS. 2-8, a handle assembly 30 consisting of the base segment 32 and a cap segment 34 is used for manually controlling the operating mechanisms 16 as well as indicating the open (OFF) and closed (ON) positions of the circuit breaker. The base segment 32 is removably engaged with the operating mechanism 16 while the cap segment 34 is positioned exterior to the cover 20 and engages with the base segment 32 through an opening 36 provided in the cover 20 for this purpose. The base segment 32 and cap segment 34 are connected such that the handle assembly 30 moves in the opening 36 during the transfer of the movable contact 14 between the open and closed positions but yet remains attached to the cover 20. Preferably, the base segment 32 is provided with an apron portion 38 extending out from the base segment 32 and in close movable engagement with the cover (see FIG. 2). The apron 38 extends out from the base segment 32 such that the opening 36 in the cover 20 is closed as the handle assembly 30 travels in the opening 36 during operation of the circuit breaker between the open and closed positions. The apron 38 prevents the insertion of foreign objects into the internal mechanisms of the circuit breaker.

Various means of removably engaging the base segment with the operating mechanism 16 can be used. Preferably, a tang 40 is provided on the operating mechanism 16 and a corresponding bore 42 is provided in the base segment 32 for receiving and engaging the tang 40. The shape of the bore 42 is such that the base segment 32 loosely sits or fits about the tang 40. The loose fit permits the tang 40 to remain in engagement with the base segment 32 of the handle assembly 30 while allowing the handle assembly to follow a line of motion differing from the line of motion followed by the tang 40 of the operating mechanism 16 during the transfer of the movable contact 14 between the open and closed positions. As can be seen in FIG. 2, during transfer of the movable contact 14 from the closed to open position or from the open to close position, the path followed by the handle assembly will be slightly longer than that followed by the operating mechanism. This allows for greater differentiation between the open (OFF) and closed (ON) positions of the circuit breaker. The loose fit between the tang 40 and the base segment 32 of the handle assembly also facilitates installation of the cover 20 and handle assembly 30 onto the the housing 18 and operating mechanism 16.

As can be appreciated, various arrangements for the engagement of the cap 34 to the base segment are possible. For example, the base segment can be provided with an additional bore for receiving a portion of the cap segment that can extend through the opening 36 in the cover 20. Preferably, however the base segment 32 is provided with an arm 44, the free end 46 of which projects through the opening 36 of the cover 20. The cap segment 34 engages a portion of the arm 44 exterior to the cover 20 forming an integral handle cover assembly. Again, the handle while being attached to the cover 20 is movable in the opening 36 thereof during the opening and closing of the circuit breaker.

The lateral surfaces 48 of the arm can be provided with a locking edge 50 intermediate the ends thereof. The cap segment 34 is provided with a bore 52 substantially conforming to the shape of the exterior portion of the arm 44. The bore surface opposite the locking edge 50 of the arm has a corresponding mating edge 54 for engaging the locking edge 50 when the cap segment 34 is placed onto the arm 44. When the locking edge 50 and mating edge 54 engage, the cap segment 34 is locked in place on the arm 44 preventing the removal of the handle assembly 30 from the cover 20. Preferably, locking edges 50 are provided on at least two opposite lateral surfaces 48 of the arm 44 with the surface of the bore 52 of the cap segment 34 having mating edges 54 corresponding to the number of locking edges 50. In order to facilitate assembly of the cap segment 34 onto the arm 44, the arm 44 and cap segment bore 52 can have corresponding tapers. The tapering would be such that the distance between the planes formed by the opposite lateral surfaces 48 of the arm decreases along a line beginning at the locking edges or mating edges and extending to the free end 46 of the arm 44.

Preferably, the cap segment 34, the base segment 32 or both should be fabricated from the material having some resilience in order to allow the engagement of the cap segment 34 onto the base segment 34 of the handle assembly 30. Typically, the resilience of the material used for fabrication allows the cap segment 34 to be snapped into place on arm 44 the base segment 32. Thus obviating the need for any fastening means such as screws or bolts. Preferably, the material of fabrication should also possess good electrical insulating properties. This eliminates the need to provide some other form of electrical insulation between the handle assembly and the operating mechanism.

With the cap segment 34 locking in place on the base segment 32, the cover 20 can now be removed from the circuit breaker 10 with the handle assembly 30 remaining attached to the cover 20 because of their size neither the cap segment nor the base segment can pass through the opening 36 in the cover 20. As shown in the figures, the portion of the handle assembly in the opening 36 in the cover 20 closely fits in the opening 36. This prevents the handle assembly 30 from rotating or twisting in the opening 36 when the cover is removed from the circuit breaker and allowing the cap segment 34 to drop through the opening 36 in the cover 20. However, it is possible to size the handle assembly 30 that is in the opening 36 and the cap segment 34 to be such that the handle assembly 30 can be rotated approximately 90.degree. to permit the withdrawal of the assembled cap segment from the cover while still attached to the base segment.

Other embodiments of the invention will be apparent to those skilled in the art from the consideration of the specification or practice of the invention disclosed. It is intended that the specification be considered as exemplary only with the true scope and spirit of the invention indicated by the following claims.