Bohrstange

摘要

817,898. Automatic circuit-breakers. LICENTIA PATENT VERWALTUNGS - G.m.b.H. Feb. 7, 1956 [Feb. 7, 1955; April 22, 1955], No. 3814/56. Class 38 (5). A miniature circuit-breaker comprises a pushbutton 5 operating a lever 6 pivoted at 71, a pin 711 on the lever moving to the left-hand end of a slot 10 in a cocking lever 9 when the button is pressed, whereby the lever 6 is overset to hold the breaker closed. The right-hand end of lever 9 rests on a latch 29 pivoted at 31 and rigid with a tripping armature 30, the lefthand end of the lever 9 being pivotally connected at 14 to a contact-carrier 12 and biassed upwardly by a restoring spring 18. The pin 14 is guided in slots 16 and the carrier 12, guided between projections 25... 25111, carries a spring-biased main contact 24 which bridges fixed contacts 27, 271. Owing to the movement of the pin 711 away from the latch 29 during the closing movement the increased tension of spring 18 does not result in the lever 9 exerting a correspondingly-increased force on the latch 29. The controlled circuit between terminals 40, 401 is completed through the contact 24, coil 32 of a tripping magnet 33 and heater coil 35 of a bimetal strip 34, the free end of the strip 34 being connected by a pin 36 to the free end of an ambient-temperature compensating bimetal strip 341 fixed to the upper end of the armature 30. Thus thermal or magnetic action causes movement of the latch 29 to release lever 9. The armature is restored by a spring 39 and the lever 6 by a spring 28. The carrier 12 also operates an auxiliary spring blade contact 21 moving it from engagement with a contact 20 into engagement with a contact 22. The contacts 24, 27, 271 lie within the field of the coil 32. A recess 11 in the slot 10 permits the button to place the breaker in an intermediate position in which all the contacts are open. In a modification, not shown, the push-button is replaced by a lever.