US2894084A

US2894084A - Operating mechanism for enclosed circuit interrupters

Info

Publication number: US2894084A
Application number: US702030A
Authority: US
Inventors: James O Rexroad; William F Born
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1957-12-11
Filing date: 1957-12-11
Publication date: 1959-07-07
Anticipated expiration: 1976-07-07
Also published as: GB850456A

Description

July 7, 1959 J. o. REXROAD ET AL 2,394,084

OPERATING MECHANISM FOR ENCLOSED CIRCUIT INTERRUPTERS Filed Dec. 11, 1957 3| %4 3| Q 1% -J r 29 29-- 34029 29" --2a 2e 34 1 '0' United States Patent Ofiice 2,894,084 Patented July 7, 1959 OPERATING MECHANISM FOR ENCLOSED CIRCUIT INTERRUP'IERS James '0. Rexroad and William F. Born, Beaver, Pa., as-

signors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 11,1957, Serial No. 702,030

11 Claims. (Cl. 200-50) The invention relates, generally, to circuit interrupters and, more particularly, to mechanisms for operating switches or circuit breakers which are enclosed in cabinets.

In connection with the operation of an enclosed circuit breaker or switch having an operating member or handle composed of a molded insulating material which is actuated by an external handle on the door of the enclosing cabinet it is desirable that there be no danger of breaking the operating member of the breaker or switch when the door of: the cabinet is closed. It is also desirable that when the door is closed the external handle should always indicate the position of the breaker operating member or handle, thereby signifying whether the breaker is open or closed.

In order to accomplish the first purpose, mecahnisms of the type described in Patent No. 2,5 50,125, issued April 24, 1951 to A. E. Schueler et al., were developed. In the aforesaid mechanism, two spaced spring arms were provided for engaging the breaker operating member or handle. The resilience of the spring arms permitted the cover to be closed regardless of the respective positions of the external handle and the breaker handle Without damaging the breaker handle because the spring arms yielded upon engaging the breaker handle if they were not in corresponding operative positions. A spring arm remained in a deflected position until the external handle was actuated to the position corresponding to the position of the breaker handle at which time the breaker handle entered the space between the spring arms. However, in the meantime, the external handle did not indicate the position of the breaker handle and there was a possibility of someone being misled into thinking that the breaker was open when it was actually closed, or vice versa.

For applications where it was very important that the external handle should always indicate the position of thebreaker handle when the cover was closed, mechanisms such as those described in Patent No. 2,806,098, of D. G. Portman et al., issued September 10, 1957, were developed. In one such mechanism, a plate was slidably mounted on the inside of the cover and an operating plate was adjustably attached to the inner side of the slidable plate which was reciprocated by means of the external handle. Two spaced rigid operating arms were attached to the operating plate. The breaker handle was. disposed in 'thespace. between the opposing ends of the operating arms when the cover was closed. Since the operating armswererigid there was danger of breaking the breaker handle by being struck by one of the rupter handle when the cover of the enclosure is closed and which eliminates the possibility of breaking the interrupter handle during closing of the cover.

Another object of the invention is to provide an operating mechanism having a one-piece resilient operating member for engaging the actuating handle of a circuit interrupter.

A further object of the invention is to provide a molded resilient member having spaced portions joined by connecting portions disposed in two planes which are perpendicular to each other.

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art.

' In accordance with one embodiment of the invention a circuit interrupter having an actuating handle composed of an insulating material is mounted in an enclosure having an openable cover. An external handle on the cover reciprocates a plate slidably mounted on the inside of the cover. A one-piece member, molded from a tough thermoplastic synthetic resin such as nylon, is attached to the plate and has two spaced portions for engaging the interrupter handle to actuate the interrupter when the cover is closed. The spaced portions are sufficiently rigid to prevent closing the cover unless the actuating handle is between said spaced portions, but not rigid enough to break the actuating handle when it is struck by one of the spaced portions.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a view, in front elevation, of an operating member of a mechanism for operating an enclosed circuit interrupter;

Fig. 2 is a view, in side elevation, of the operating member; I v

Fig. 3 is a view, in section, taken along the line III--III in Fig. 1;

Fig. 4 is a view, in rear elevation, of the operating member;

Fig. 5 is a reduced view, in side elevation, of the operating mechanism, and

Fig. 6 is a reduced view, in front elevation, of the operating mechanism.

Referring to the drawing, and particularly to Figure 6, the strcuture shown therein comprises a portion of a cabinet for housing a circuit interrupter which may be either a manually operable switch or an automatic circuit breaker. When an automatic circuit breaker is utilized, it is preferably of the type described in Patent No. 2,047,739, issued to H. J. Lingal, July 14, 1936. The cabinet for housing the interrupter is provided with an openable cover 11 having an external operating handle 13 mounted thereon. As will be described more fully hereinafter, the handle 13 is utilized for operating the switch or circuit breaker mounted inside the cabinet. The cabinet and the mounting of the circuit breaker therein may be as disclosed in the aforesaid patents to Schueler et a1. and Portman et al.

The circuit breaker is provided with contact members and an operating mechanism for opening and closing the contact member by means of an actuating member or handle 15 which is usually made of a rather brittle molded insulating material. As described in the aforesaid patent, the circuit breaker is also provided with a tripping mechanism which is operable in response to a predetermined overload current to effect automatic opening of the contact members.

,As previously mentioned, the contact members of the circuit breaker may be manually opened and closed by I oscillatory movement of the actuating member or .handle which is actuated by movement of the external operating handle 13. As indicated in Figure 6, the operating handle 13 may be moved to an on position to close the contact members of the circuit breaker. The handle 13 may be moved to an olf position to open the, contact members of the circuit breaker. The handle 13 is automatically moved to a trip position when the contact members of the circuit breaker are opened by its overload tripping mechanism. The handle 13 may be moved to a reset position and then to the on position in order to reclose the contact members of the breaker after they have been opened by the tripping mechanism.

The operating mechanism may be generally of a type described in the aforesaid patent of D. G. Portman et al. As shown, the handle 13 has a short extension or shaft 16 which is rotatably mounted in the cover 11 and extends through a cam-shaped plate 17 which is secured to the inner end of the shaft 16. The plate 17 carries a pin or anti-friction roller 18 which is disposed in a slot 19 in a slida-ble plate 21. The plate 21 is supported between grooved studs 22 mounted on the inside of the cover 11.

An operating member 23 is adjustably attached to the inner side of the plate 21 by means of screws 24 which extend through elongated openings 25 in the member 23 and are threaded into the plate 21. Two spaced

portions

26 and 27 are provided on the operating member 23. The actuating handle 15 of the circuit breaker is disposed in the space between the opposing ends of the spaced

portions

26 and 27 of the operating member 23.

Thus, rotation of the handle 13 rotates the cam plate 17 which slides the plate 21 by means of the pin and

slot connection

18 and 19. The ends of the spaced

portions

26 and 27 of the operating member 23 engage the actuating handle 15 to operate the circuit breaker. The connection between the operating member 23 andthe circuit breaker handle 15 is made as the cover 11 is being closed.

As explained hereinbefore, the actuating handle 15 of the circuit breaker is composed of an insulating material which is a relatively brittle molded material. Therefore, it is desirable that there shall be no danger of breaking the handle 15 when the door of the enclosure is being closed. It is also desirable that when the door 11 is closed the external handle 13 should always indicate the position of the breaker handle 15. As explained hereinbefore, an operating mechanism which functions in a manner to provide the first of the aforesaid desirable features has been utilized previously. Also an operat ing mechanism which functions in a manner to provide the second of the aforesaid desirable features has been utilized. In order to include both of the aforesaid features in one operating mechanism, the operating member 23 herein described has been devised. As shown more clearly in Figures 1 to 4, the operating member 23 comprises the two spaced box-

like portions

26 and 27. The flat surfaces at the under side of the

portions

26 and 27 extend substantially parallel to the inside of the cover and to each side of the slot between the two portions a distance as great as the travel of the handle 15 so that the handle 15 must be positioned in the slot or space be tween the two

portions

26 and 27 in order to close the cover 11. on the cabinet or box enclosing the circuit interrupter. As shown, the connecting

portions

28 and 29 are disposed in. planes which are perpendicular to each other. The portion 28 is in a plane parallel to the plane of the sides of the box-

like portions

26 and 27. The portion 29 is in a plane parallel to the bottom walls of the

portions

26 and 27. The box-

like portions

26 and 27 are open at the top.

The operating member 23, or at least the two spaced portions thereof 26 and 27, are made of an organic elastomeric material and in particular of a synthetic resin, usually thermoplastic so that it may be readily molded, which is tough and somewhat flexible and resilient, at least in relatively thin sections. Examples of such tough thermoplastic synthetic resins include nylon, polyethylene, polyurethane and plasticized polyvinyl chloride and polyvinyl acetate. Such materials have the advantage that they are harder and tougher than rubber and have better ageing characteristics than rubber does under adverse conditions. By making the

portions

26 and 27 hollow or with voids, the materials mentioned may be used even though a solid block of some of the materials would be too hard to insure that the handle 15, which is usually made of a relatively brittle and rigid molded resin, will not be broken if the cover of the enclosure is slammed with one of the

portions

26 or 27 hitting the upper end of the handle.

The operating member 23 is preferably molded from nylon, which is particularly suitable since it can be molded in very thin sections. The bottom walls and the sides of the box-

like portions

26 and 27 are relatively thin. Furthermore, nylon has a modulus of elasticity of approximately 300,000 p.s.i. as compared with hard rubber which has a modulus of elasticity of 150,000 p.s.i. and steel which has a modulus of elasticity of 30,000,000 p.s.i. There-fore, the member 23 is sufficiently rigid to prevent closing the cover 11 unless the external handle 13 is in a position corresponding to the position of the breaker handle 15, but the member 23 is not rigid enough to break the handle 15 in case the

handles

13 and 15 are not in corresponding positions and the bottom wall of one of the spaced

portions

26 or 27 strikes the handle 15. The member 23 is resilient enough to absorb a great amount of shock when it strikes the breaker handle thereby reducing the impact on the breaker handle and preventing breakage of the handle 15.

It will be noted that a longitudinally extending reinforcing rib 31 is provided at the center of the portion 26. A similar reinforcing rib 32 is provided at the center of the portion 27 These ribs are disposed on the inside of the portions and extend between bosses 33 and end walls 34 which engage the breaker handle 15. The elongated openings 25 for attaching the member 23 to the plate 21, in the manner previously described are provided in the bosses 33. The reinforcing

ribs

31 and 32 strengthen the bottom walls of the

portions

26 and 27 which strike the breaker handle 15 in case the

handles

13 and 15 are not in a corresponding position when an attempt is made to close the cover 11. Since the portion 26 is longer than the portion 27, the reinforcing rib 31 is of a greater depth than the rib 32 as shown in Figure 3.

The member 23 has additional advantages of a rela-. tively low initial tooling cost and a relatively low cost per item. The one integral piece which may be molded from other plastic materials as well as from nylon replaces three pieces which were riveted together in one of the mechanisms previously utilized. Therefore, the cost of assembling the operating mechanism is reduced.

As previously explained, the present member 23, because of its configuration and the material of which it is composed, functions in the manner of one of the operating members previously provided to prevent closing the cover of the cabinet unless the external operating handle and the interrupter handle are in corresponding positions. Also the present member practically eliminates breakage of: the interrupter handle in case an attempt is made to close the cover without the external operating handle and the interrupter handle being in corresponding positions.

As described in the aforesaid Portman et 211. patent an interlocking device is provided to prevent opening the cover 11 while the contact members of the circuit interrupter are closed. An interlocking latch 37 is pivotally attached to the cover 11 by means of a screw 38 which extends through a bearing in the cover 11. The screw 38 is threaded into and fixed to the latch 37 in order that the latch may be actuated by means of the screw for a purpose which will be explained hereinafter. The

latch 37 has a clearance opening 41 therein for the shaft 16 to permit the latch to be moved relative to the shaft.

The latch 37 has an inwardly extending arm 42 thereon which is disposed to engage a locking element 43 attached to the inside of the cabinet. The arm 42 is biased by a spring 44 into a position in which the arm 42 engages a hook portion 45 of the element 43 when the external operating handle 13 is in the on position and the actuating member 15 is in the closed position of the circuit breaker. Thus, the cover 11 normally can not be opened while the circuit breaker is closed.

In order to permit the cover to be opened by an authorized person in the event of failure of the circuit breaker mechanism, the screw 38 may be turned by means of a screwdriver to release the interlocking latch 37 from engagement with the element 43. It will be noted that the head of the screw 38 is exposed when the external operating handle 13 is in the .on position. However, the head of the screw 38 is covered by the handle 13 when the handle is in the ofi position, thereby permitting the breaker to be locked off and the cover locked closed by inserting a padlock in openings 47 in the handle 13.

The interlocking latch 37 is normally released from engagement with the hook 45 on the element 43 when the external operating handle 13 is moved past the oil position toward the reset position. The arm 42 is engaged by a shoulder 46 on the plate 17 to disengage the latch 37 from the element 43. Thus, the cover 11 may be released by movement of the handle 13 only when the handle is moved to about the reset position.

From the foregoing description, it is apparent that the present invention provides an operating mechanism for an enclosed circuit interrupter which is relatively simple in construction and which functions to prevent closing the cover of the cabinet containing the interrupter unless the external operating handle and the actuating handle are in corresponding positions. Furthermore, the present mechanism practically eliminates the possibility of breaking the actuating handle of the interrupter by attempting to close the door of the cabinet without the external handle and the interrupter handle being in corresponding positions.

Since numerous changes may be made in the above described construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, an operating member movably mounted inside of the cover, an external handle having a portion extending through the cover, an integral member composed of a material having a modulus of elasticity higher than rubber but less than steel attached to said operating member, said integral member having an opening therein for receiving the actuating handle of the interrupter when the cover is closed, and means driven by said external handle for reciprocating the operating member and the integral member to operate the circuit interrupter.

2. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, a guiding member movably mounted on the inside of the cover, an external handle with a part extending through the cover, actuating means having spaced hollow portions carried by said guiding member to engage the actuating handle of the circuit interrupter when the cover is closed, said spaced hollow portions of the actuating means having relatively thin walls extending to each side of the space between the portions at a distance from the inside of the cover to prevent closure of the cover unless said actuating handle is between the spaced portions, said spaced hollow portions being of a thermoplastic synthetic resin which is suflicient- 1y rigid to prevent closing the cover unless said actuating handle is between said spaced portions but not rigid enough to break the actuating handle when it is struck by a wall of one of said spaced portions, and means driven by said external handle for reciprocating the guiding member and the actuating means to operate the circuit interrupter.

3. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, an operating member movably mounted inside of the cover, an external handle having a part extending through the cover, an integral member composed of a synthetic resin having a modulus of elasticity higher than rubber but less than steel attached to said operating member, said integral member of synthetic resin having an opening therein for receiving the actuating handle of the interrupter when the cover is closed, and means driven by said external handle and engaging the integral member to reciprocate the operating member and the integral member of synthetic resin to operate the circuit interrupter.

4. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, an operating member movably mounted inside of the cover, an external handle having a part extending through the cover, an integral member composed of a material having a modulus of elasticity higher than rubber but less than steel attached to said operating member, said integral member having an opening therein for receiving the actuating handle of the interrupter when the cover is closed, and means driven by said external handle to reciprocate the operating member and the integral member to operate the circuit interrupter.

5. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination an operating member slidably mounted on the inside of the cover, an external handle having a shaft extending through the cover, an integral member composed of a material having a modulus of elasticity higher than rubber but less than steel attached to said operating member, said integral member having an opening therein for receiving the actuating handle of the interrupter when the cover is closed, an actuating member having spaced portions composed of a material less rigid than steel carried by said guiding member, said actuating handle being disposed between said spaced portions when the cover is closed, and means driven by said shaft for reciprocating the guiding member and the actuating member to operate the circuit interrupter.

6. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, an operating member movably mounted inside of the cover, an external handle having a part extending through the cover, a molded one-piece actuating member of organic material having hollow portions therein to make it more resilient carried by said operating member, said actuating member of organic material having an opening therein for receiving the actuating handle of the circuit interrupter when the cover is closed, and means driven by said external handle for reciprocating the operating member and the actuating member to operate the circuit interrupter.

7. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, an actuating member of synthetic resin reciprocally mounted on the inside of the cover, an external handle having a part extending through the cover, said actuating member of synthetic resin comprising two spaced resilient portions joined by integrally formed connecting portions, the actuating;

handle of the circuit interrupter being disposed in the space between said resilient portions when the cover is closed, and means driven by said external handle for re ciprocating the actuating member of synthetic resin to operate the circuit interrupter.

8. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, an operating member movably mounted inside of the cover, an external handle having a part extending through the cover, an actuating member composed of a resilient organic material attached to the operating member, said actuating member comprising two spaced portions joined by integrally formed connecting portions, the actuating handle of the circuit interrupter being disposed between the spaced portions when the cover is closed, and means driven by said external handle for reciprocating the op erating member to operate the circuit interrupter.

9. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, a guiding member slidably mounted on the inside of the cover, an external handle having a shaft extending through the cover, an actuating member composed of a resilient material attached to the guiding member, said actuating member comprising two spaced box-like portions joined by integrally formed connecting portions disposed in planes at right angles to each other, the actuating handle of the circuit interrupter being disposed between said box-like portions when the cover is closed, and means driven by said shaft for reciprocating the guiding member to operate the circuit interrupter.

10. In an operating mechanism for a circuit interrupter having an actuating handle and mounted in an enclosure having an openable cover, in combination, a guiding member slidably mounted on the inside of the cover, an external handle having a shaft extending through the cover, an actuating member composed of a resilient material attached to the guiding member, said actuating member comprising two spaced box-like portions joined being sufficiently rigid to prevent closing the cover unless the actuating handle is between said spaced portions but not rigid enough to break the actuating handle when it is struck by one of said walls, and means driven by said shaft for reciprocating the guiding member to operate the circuit interrupter.

11. In an operating mechanism for a circuit interrupter having an actuating handle. and mounted in an enclosure having an openable cover, in combination, an operating member movably mounted inside the cover, an external.

handle having a part extending through the cover for moving said operating member, actuating means having spaced hollow portions carried by said operating member to engage said actuating handle to operate the circuit interrupter when the cover is closed, said spaced hollow portions of the actuating means having relatively thin walls extending to each side of the space between the portions at a distance from the inside of the cover to pre vent closure of the cover unless said actuating handle is between the spaced portions, and said spaced hollow portions being of organic material which is sufficiently rigid to prevent closing the cover unless said actuating handle is between said spaced portions but not rigid enough to break the actuating handle when it is struck by a wall of one of said spaced hollow portions.

Schueler et a1 Apr. 24, 1951 Portrnan et a1 Sept. 10, 1957