Circuit breaker trip latch assembly
AssigneeGeneral Electric Company
InventorsRoger N. Castonguay, Charles L. Jencks
Life of this patent
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Abstract
A circuit breaker trip latch assembly includes a primary latch having a latching member releasably latching a cradle in its reset position against the bias of charged operating mechanism springs. The primary latch and either one of the first and second secondary latches commonly engage a latch pin carried by the free end of a pivotally mounted, elongated intermediate latch. The geometry of this common engagement is such as to greatly reduce the force of the charged mechanism springs ultimately absorbed by the first secondary latch as the cradle is relatched and the second, trip initiating, secondary latch while the breaker is closed.
Claims10
A trip latch assembly for releaseably latching the cradle of a circuit breaker operating mechanism in a reset position, said trip latch assembly including, in combination:
- A. an elongated primary latch pivotally mounted intermediate its ends;
- B. a primary latch element pivotally mounted to said primary latch adjacent one end thereof;
- C. a latch spring biasing said latch element to a latching position engageable with a cradle latching shoulder to sustain the cradle in its reset position against the force of a charged breaker operating mechanism spring exerting a moment on said primary latch;
- D. a first secondary latch pivotally mounted for movement to a latching position in response to opening of the breaker and to an unlatching position in response to closure of the breaker;
- E. a second secondary latch pivotally mounted for movement between latching and unlatching positions;
- F. an elongated intermediate latch pivotally mounted adjacent one end;
- G. an intermediate latch element mounted adjacent the other end of said intermediate latch in a position of common engagement with the other end of said primary latch and either said first secondary latch in its latching position while the breaker is open or said second secondary latch in its latching position while the breaker is closed, the geometry of the engagements of said primary and secondary latches with said intermediate latch element, coupled with the elongation of said intermediate latch, being effective in significantly attenuating the force of the charged breaker operating mechanism spring ultimately absorbed by said secondary latches,
- (1) whereby, upon movement of said second secondary latch to its unlatching position in disengaged relation with said intermediate latch element, said primary latch is freed to pivot from a latching position to an unlatching position where said primary latch element is swung away from engaging relation with the cradle shoulder and the cradle is propelled to its tripped position as the operating mechanism spring discharges to open the breaker.
Dependencies are inferred from the claim text.