US3821532A - Handle extension assembly for a molded case electric circuit breaker - Google Patents

Abstract

The handle extension assembly is readily mounted on the external portion of an operating handle of a molded case circuit breaker. It comprises a pair of mounting blocks fixedly mountable on opposite sides of the handle and a lever portion pivotally mounted on the mounting blocks so as to be movable from an inoperative position to an operative position where it facilitates manual movement of the handle.

Description

United States Patent 1191 Isaac, Jr. et al.

HANDLE EXTENSION ASSEMBLY FOR A MOLDED CASE ELECTRIC CIRCUIT BREAKER Inventors: Donald Isaac, Jr.; Clifford F.

Bishop, both of Cedar Rapids, Iowa Assignee: Square D Company, Park Ridge, 111. Filed: June 7, 1973 App]. No.: 367,999

Int. Cl; H0lh 3/02, H0111 1/00 Field of Search 200/172 R, 172 A; 74/491, 74/544 References Cited UNITED STATES PATENTS 10/1955 Allen 200/172 A 12/1955 Berndsen 200/172 A 1 June 28, 1974 3,142,744 7/1964 Keck 200/172 A 3,159,048 12/1964 Clifford... 74/544 X 3,175,420 3/1965 Craig 200/172 A 3,496,320 2/1970 Wasileski 200/172 A Primary E.raminer-Robert K. Schaefer Assistant Examiner.Wi11iam .1. Smith Attorney, Agent, or FirmHarry G. Thibault; Harold J. Rathbum [5 7 ABSTRACT The handle extension assembly is readily mounted on the external portion of an operating handle of a molded case circuit breaker. It comprises a pair of mounting blocks fixedly mountable on opposite sides of the handle and a lever portion pivotally mounted on the mounting blocks so as to be movable from an inoperative position to an operative position where it facilitates manual movement of the handle.

2 Claims, 4 Drawing Figures HANDLE EXTENSION ASSEMBLY FOR A MOLDED CASE ELECTRIC CIRCUIT BREAKER This invention relates to a handle extension assembly for a relatively large electric circuit breaker of the molded-case type.

The operating handle of a relatively large circuit breaker of the molded-case type requires a substantial amount of force for manual operation. However, such circuit breakers are often mounted in confined areas where space is not available for handles of a length which would adequately reduce the required operating force. Therefore, it has been common practice to provide the handle with a pivotal extension member which can be moved from an out of the way position to an operative position when it is necessary to manually operate the circuit breaker. An example of such an extension member for use on two adjacent handles is shown in the U.S. Pat. No. 3,159,048, issued to Joseph Clifford on Dec. 1, 1964.

It has been difficult to provide a handle extension which can be readily secured to a single operating handle in the field and remain secured under the forces required to operate the circuit breaker manually.

In accordance with this invention, a handle extension assembly is provided which has a base portion that can be rigidly fixed to an unmodified external portion of an operating handle of a circuit breaker and a lever portion pivotally mounted on the base portion so that the lever portion can be pivotally displaced out of the way when the handle extension assembly is not in use.

Accordingly, an object of this invention is to provide an improved handle extension assembly for the operating handle of a molded case circuit breaker, the extension assembly having a base portion which can be fixedly mounted on the handle without modification of the handle, and a lever portion pivotally mounted on the base portion.

Other objects and advantages will appear when the following specification is considered together with the accompanying drawings, in which:

FIG. 1 is a perspective view of a molded case circuit breaker having a handle extension assembly constructed in accordance with the invention mounted on an operating handle of the circuit breaker and having a portion of the assembly broken away;

FIG. 2 is a side view of the handle extension assembly of FIG. 1 in the operative position shown in phantom in FIG. 1;

FIG. 3 is a fragmentary sectional view taken generally along the line 3-3 of FIG. 2; and

FIG. 4 is a fragmentary sectional view taken generally along the line 4--4 of FIG. 3.

A handle extension assembly constructed in accordance with this invention is shown mounted on a multi-pole circuit breaker 12 of molded case construc- 4 tion such as disclosed in US. Pat. No. 3,355,685, is-

sued Nov. 28, 1967, but its use with other circuit breakers will be readily apparent. The circuit breaker 12 has a conventional swingable external operating handle 14 which is movable lengthwise of the circuit breaker between two extreme positions. A gripping portion of the handle 14 tapers inwardly away from the body portion of the circuit breaker 12 as shown in FIG. 3.

The handle extension assembly 10 includes a base portion comprising a pair of identical mounting blocks 16. As shown best in FIG. 4, each block 16 has a recess I611 flanked by opposite end flanges I6b and l6( and also has inwardly extending top flanges l6e at each end of the block. The recess 16a is defined by an inner face 16d of each block 16, the inner face 16d sloping outwardly downwardly as viewed in FIG. 3 to conform with the taper of the operating handle 14. An insert plate 17 having a plurality of outwardly directed spaced gripping teeth 18 on one surface is adhesively bonded to the inner face 16d of each block 16 and has an upper curved portion received in a groove 16f and a lower curved portion which wraps around a lower edge of the inner face 16d.

The assembly also includes two Z-shaped lever members 22 which are pivotally mounted on the respective blocks 16 by respective rivets 24 which are staked or press fitted into respective openings 26 in the blocks 16, the openings 26 having respective counterbores 27. The Z-shaped members are in reversely positioned relationship as shown and their upper end portions are secured together by a two-piece knob 28. Each portion of the knob 28 is slotted to receive a side edge portion of each lever member and the portions are secured together by a rivet or bolt 29 passing through aligned openings.

When the handle extension assembly 10 is mounted on the handle 14, the tapered portion of the handle vl4 (FIG. 3) is received in the facing recesses 16a in the blocks 16 and the flanges 16b and partially enclose the side edges of the handle 14. Fasteners 30 pass through aligned openings 32 in the respective pairs of juxtaposed flanges 16b and 160 for securing the mounting blocks 16 to the handle 14. In the secured position, the gripping teeth 18 on the plates 17 bitingly engage the tapered portion of the handle 14.

The lever members 22 are placed in the un-extended position shown in solid lines in FIG. 1 when not in use and can be pivoted upwardly to the operating position shown in phantom in FIG. 1 when it is desired that the circuit breaker 12 be turned on or off.

As shown in FIG. 1, the circuit breaker 12 may be provided with a lockoff bracket 34 whereby a padlock 36 (in phantom) may be placed selectively through openings 38 in the bracket to secure the operating handle 14 of the circuit breaker 12 in a fixed position. A screw 39 may be threaded into a suitable opening in the bracket 34 to act as a deterrent preventing inadvertent movement of the handle 14.

If desired, the lever members 22 may have aligned openings 40 for reception of a pin (not shown) to prevent pivotal movement of the lever members 22 from the operating position.

I claim:

1. A handle extension assembly for a molded case circuit breaker having a four-sided swingable external operating handle at least two opposite sides of which are convergent in a direction outwardly of the circuit breaker, the assembly comprising a pair of recessed mounting blocks defining, when in juxtaposed relation, a four-sided recess therebetween which is complementary t0 the handle, fastening means securing the blocks in juxtaposed relationship with the handle in the recess, two opposite sides of the recess being divergent in a direction toward the circuit breaker, each divergent side of the recess having a gripping surface for engaging respective converging sides of the handle defined by a plate secured thereto, each plate having a plurality of gripping teeth thereon, the fastening means clamping the blocks to the handle, two elongated lever members,

vergency of the sides of the recess and to an operative position aligned with the handle.

2. A handle extension assembly as claimed in claim 1 wherein the lever members are Z-shaped and reversely positioned with respect to each other.

Claims (2)

1. A handle extension assembly for a molded case circuit breaker having a four-sided swingable external operating handle at least two opposite sides of which are convergent in a direction outwardly of the circuit breaker, the assembly comprising a pair of recessed mounting blocks defining, when in juxtaposed relation, a four-sided recess therebetween which is complementary to the handle, fastening means securing the blocks in juxtaposed relationship with the handle in the recess, two opposite sides of the recess being divergent in a direction toward the circuit breaker, each divergent side of the recess having a gripping surface for engaging respective converging sides of the handle defined by a plate secured thereto, each plate having a plurality of gripping teeth thereon, the fastening means clamping the blocks to the handle, two elongated lever members, means securing the lever members together at one end portion oF each in side-byside relation, means pivotally mounting the lever members at their other end portions on the respective blocks with the pivot axes in axial alignment, the lever members being pivotal between an inoperative position transverse to the direction of divergency of the sides of the recess and to an operative position aligned with the handle.

2. A handle extension assembly as claimed in claim 1 wherein the lever members are Z-shaped and reversely positioned with respect to each other.

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