GB1264603A - - Google Patents

Abstract

1,264,603. Vacuum switches. GENERAL ELECTRIC CO. 27 Jan., 1970 [3 Feb., 1969], No. 3905/70. Heading H1N. A vacuum type circuit interrupter has a movable contact with a stroke-length control responsive to the current through the contacts. In Fig. 1 a movable contact 17 is mounted on a conductive operating rod 17a rigidly attached to pivoted cross-bar 26 which is connected via a pull-rod 34 to actuating lever 30. This lever is biased into an "opening" position by springs 39, 32 but is prevented from moving by the latched closing rod 40. When tripped, the cross-bar and operating rod move downwards until the crossbar meets either of the stops 60, 62. Stop 60 is a pivoted lever normally maintained in the position shownby a reset spring 68 so as to thereby limit the opening stroke to a relatively small value. When the interrupter current exceeds a predetermined value, e.g. a short-circuit current, the stop 60 is rendered ineffective, being moved by the attraction of U-shaped magnetic core 72 which partially surrounds the current carrying conductive braid 50. In a polyphase arrangement, Fig. 3 (not shown), the lostmotion connection 41, (41a, 41b) of each phase enables the length of the opening stroke in any one phase to be determined by the stops in that particular phase and not be affected by the stops in the other phases. The arrangement has a solenoid-operated trip and reset mechanism and a common crank-operating shaft. In Fig. 4, a relatively short stop 90, which is ineffective during light current capacitance switching operations requiring a longer opening stroke, is provided for excessive, e.g. short-circuit, currents. The interrupter is tripped either by a push-button 86 or an overcurrent switch 88. In Fig. 5 (not shown), a solenoid operated latch mechanism releases the short stop into its effective position, a reset member (99) being associated with the operating rod.