Claims
- 1. A circuit breaker assembly comprising:
- a pair of separable contacts;
- operating means including a pair of operating springs under the control of an on-off handle and a trip bar;
- latch means operatively abutting said operating means for opening said contacts upon pre-determined current through said contacts; and
- arc chute means for controlling arcs which occur upon opening said contacts;
- said latch means including;
- a primary latch supported on a side frame by a primary latch pivot and capturing an end of a cradle pivotally connected within said operating means defining a first point of reference;
- a secondary latch supported on said side frame by a secondary latch pivot and operatively abutting said primary latch whereby a surface on said secondary latch at a first end is in interfering relation with a surface on said primary latch defining a second point of reference holding said primary latch from rotation when said cradle is captured by said primary latch said secondary latch releasing said primary latch upon motivation by said trip bar at a third point of reference on said secondary latch opposite said first end;
- said primary latch pivot being offset from said first point of reference by a first distance (X.sub.1) in a first plane and from said second point of reference by a second distance (X.sub.2) in a second plane perpendicular to said first plane;
- said secondary latch pivot being offset from said second point of reference by a third distance (X.sub.3) in said first plane and being offset from said third point of reference by a fourth distance (X.sub.4) in said second plane; whereby a trip force exerted on said secondary latch to separate said primary and secondary latches is given by: ##EQU2## when P1 is a latch force provided by said contact springs,
- .omega. is a coefficient of friction,
- X.sub.2 /X.sub.1 is the ratio of said second separation distance to said first separation distance,
- X.sub.4 /X.sub.3 is the ratio of said fourth separation distance to said third separation distance said fourth separation distance being greater than said third separation distance.
- 2. The circuit breaker of claim 1 wherein the ratio of said second to said first separation distance varies from 2 to 1 to 10 to 1.
Parent Case Info
This is a continuation-in-part of co-pending Ser. No. 500,643 filed June 2, 1983, abandoned.
US Referenced Citations (6)
Non-Patent Literature Citations (1)
Entry |
D. Eugene Ostergaard, "Advanced Die Making", McGraw-Hill Book Company, 1967 Edition, pp. 116-118. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
500643 |
Jun 1983 |
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