US3585541A

US3585541A - Electric circuit breaker with pushbutton for tripping

Info

Publication number: US3585541A
Application number: US858348A
Authority: US
Inventors: Kenneth W Erickson
Original assignee: Square D Co
Current assignee: Schneider Electric USA Inc
Priority date: 1969-09-16
Filing date: 1969-09-16
Publication date: 1971-06-15
Anticipated expiration: 1988-06-15
Also published as: GB1259228A

Abstract

An electric circuit breaker with a recessed pushbutton operable to move an armature member and an ambient temperature compensating bimetallic latching member endwise. Because of the manner in which the armature member is mounted, the members are also rotated to move the free end of the latching member out of latching relationship with a releasably latchable trip lever releasable to effect separation of a pair of contacts.

Description

United States Patent Kenneth W. Erickson Cedar Rapids. Iowa 858,348

Sept. 16, 1969 June 15, 1971 Square D Company Park Ridge, lll.

lnventor Appl. No. Filed Patented Assignee ELECTRIC CIRCUIT BREAKER WITH PUSl-IBUTTON FOR TRIPPING 2 Claims, 5 Drawing Figs.

U.S. CL 335/45, 3 37/66 Int. Cl. H0lh 71/12 Field of Search 335/43, 45, 42, 37', 337/66 [56] References Cited UNITED STATES PATENTS 2,952,757 9/ 1960 Ellenberger 337/66 3,061,697 10/1962 Kralik 335/37 3,275,959 9/1966 Locher 335/45 Primary Examiner-Harold Broome Attorneys-Harold J. Rathbun and Paul J. Rose ABSTRACT: An electric circuit breaker with a recessed pushbutton operable to move an armature member and an ambient temperature compensating bimetallic latching member endwise. Because of the manner in which the armature member is mounted, the members are also rotated to move the free end of the latching member out of latching relationship with a releasably latchable trip lever releasable to effect separation of a pair of contacts.

ELECTRIC CIRCUIT BREAKER WITH PUSI-IBU'ITON FOR TRIPPING An object of the invention is to provide a push-to-trip feature for a circuit breaker having an armature member, a latching member, and a magnetic core member constructed and arranged generally as in the circuit breaker disclosed in U.S. Pat. No. 3,06l,697, which is hereby incorporated herein by reference.

In the drawings, FIG. I is a fragmentary front view of a circuit breaker constructed in accordance with the invention;

FIG. 2 is an enlarged perspective view of the pushbutton of the circuit breaker of FIG. I;

FIG. 3 is a fragmentary side view of the circuit breaker of FIG. 1, the side cover having been removed and the trip lever being shown in latched position;

FIG. 4 is a view similar to FIG. 3, but showing the trip lever in tripped position; and

FIG. 5 is an enlarged fragmentary sectional view of a portion of FIG. 4.

- Parts of the circuit breaker of this invention substantially identical to the parts of the circuit breaker of U.S. Pat. No. 3,061,697 are identically numbered, and reference may be had to the patent for a complete description.

In accordance with this invention, a pushbutton member 80 is reciprocally mounted in the base 12 adjacent the opening for the handle 25. The member 80 includes an outer end portion 80a (FIG. 2) and an inner portion 80b. The outer surface of the portion 800 is normally substantially flush with the outer surface of the surrounding portion of the base 12, as can be noted in FIG. 3. The inner portion 80b is wider than the portion 80a and presents a shoulder at 800 (FIG. 2) for engagement with an inner surface of the base 12 to limit outward movement of the member 80. The inner end of the portion 80b is provided with a recess 80d for reception of the adjacent joined ends of the bimetallic armature 64 and the ambient temperature compensating bimetallic strip 73.

The finger portion 68 extends at an angle from the main portion of the armature 64 through the slot 69 in the portion 70 of the magnetic core 51. When the push button member is depressed, as in FIG. 4, the main portion of the armature 64 is moved longitudinally, but because the finger portion 68 is confined in the slot 69 in the magnetic core portion 70, the armature 64 is also rotated counterclockwise toward the magnetic core 51 from the position of FIG. 3 to the position of FIG. 4. The amount of movement is relatively small, but it is sufficient to move the bimetallic strip 73 out of latching relationship with the releasably latchable trip lever 34, just as when the armature 64 is magnetically attracted toward the magnetic core 5 I.

lclaim:

1. In an electric circuit breaker having a casing, a pair of separable contacts in the casing, a releasably latchable trip lever pivotally mounted in the casing and releasable from a latched position to effect separation of the contacts, a terminal strap extending into the casing, a bimetallic strip secured adjacent one end to an inner end portion of the terminal strap, a magnetizable core in the casing secured to the bimetallic strip and having an extension with a slot therein, an elongated generally flat armature in the casing pivotally mounted adjacent one end on the core, extending generally parallel to the bimetallic strip, and having a finger portion at the other end extending at an angle to the remainder thereof through the slot in the extension of the core, and an elongated generally flat latching member in the casing secured adjacent one end to the one end of the armature, extending generally parallel to the armature and to the bimetallic strip, and normally latching the trip lever with the other end portion thereof, the improvement comprising a pushbutton extending into the casing in endwise alignment with the armature and latching member adjacent their joined ends and depressible'to move the armature and latching member longitudinally and pivot the t ri lever while the angled finger portion of the armature IS gui ed by the extension of the core to cause pivotal movement of the armature and latching member and disengagement of the latching member from the trip lever.

2. An electric circuit breaker as claimed in claim I, wherein the armature and latching member are bimetallic strips.

Claims

1. In an electric circuit breaker having a casing, a pair of separable contacts in the casing, a releasably latchable trip lever pivotally mounted in the casing and releasable from a latched position to effect separation of the contacts, a terminal strap extending into the casing, a bimetallic strip secured adjacent one end to an inner end portion of the terminal strap, a magnetizable coRe in the casing secured to the bimetallic strip and having an extension with a slot therein, an elongated generally flat armature in the casing pivotally mounted adjacent one end on the core, extending generally parallel to the bimetallic strip, and having a finger portion at the other end extending at an angle to the remainder thereof through the slot in the extension of the core, and an elongated generally flat latching member in the casing secured adjacent one end to the one end of the armature, extending generally parallel to the armature and to the bimetallic strip, and normally latching the trip lever with the other end portion thereof, the improvement comprising a pushbutton extending into the casing in endwise alignment with the armature and latching member adjacent their joined ends and depressible to move the armature and latching member longitudinally and pivot the trip lever while the angled finger portion of the armature is guided by the extension of the core to cause pivotal movement of the armature and latching member and disengagement of the latching member from the trip lever.

2. An electric circuit breaker as claimed in claim 1, wherein the armature and latching member are bimetallic strips.