Patent GB-157396-A (GB)
Title: Improvements in and relating to automatic electric switches
IPC: H01H75/04
Filed: 1921-01-10
Abstract: 157,396. Bollinger, H. Aug. 19, 1913, [Convention date]. Automatic circuit-breakers; oil switches; weight actuation.-A circuit-breaker when tripped electromagnetically is automatically re-. closed even if the overload persists, the automatic release, with or without the interposition of a time-delay mechanism, releasing a mechanical source of power for re-closing the circuitbreaker after which the source of power is again locked in readiness for a subsequent release of the circuit-breaker. As applied to an oil switch having an operating spindle 6 with handwheel 1, a grooved pulley 2 is loosely mounted on the spindle 6, a ratchet plate 9 being secured to the pulley 2. A steel rope 3 accommodated in the pulley 2 passes over another pulley 5 supported in a bracket 4 and terminates in a weight 7, therope passing through a hole 18 in a lateral plate- 4<a>. On the shaft 6 is also secured a disc 9 having a link eye 10. A link 11 extends from the eye 10 into other end having a slot 12 in which works a pin 13 of a two-armed lever 14 pivoted at 15 on the plate 4a. The lever 14 is pressed by a spring 16 to engage the rope 3, which has two, stops 19<a>, 19<b> to co-operate with the lever 14 in holding the weight 7 in one or other of its two raised positions. The disc 9 has a lateral arm b which carries pivotally at c a pawl d, its hooked nose being pressed against the ratchet plate a by a leaf spring d<1>. To set the switch and re-closing mechanism the weight 7 is first raised and held (Fig. 1) by clockwise rotation of the pulley 2, the switch then being closed by anticlockwise rotation of the handwheel 1. The closure of the switch moves the lever 11 from right to left and, when the pulley 2 is released, the stop 19<a> by resting on the forked end of the lever 17 locks the weight 7 in its raised position, the pawl d at the same time holding the pulley 2 by engaging a tooth on the ratchet plate a.. The swich is provided with a pull-off spring and is automatic. ally latched in its closed position. When this latch is released on overload by energization of the electromagnet 8, the spindle 6 with the wheel 1 is moved by the switch spring in a clockwise direction carrying the pulley 2 until the pawl d is raised by a lever g attached by a link to the armature e, the lever g depressing one arm of a pivoted bell-crank lever h the other arm of which is thereby moved into the path of the lower end of the pawl d. The switch spindle now completes its opening movement, at the end of which the end 17 of the lever 14 is moved from under the stop 19<a>, the pawl d at the same time engaging the next tooth on the ratchet plate a. The weight 7 now drops reclosing the switch, its motion being arrested when the stop plate 19<b> engages the end 17 of lever 14 which is moved into its path during the switch closing movement. If the overload persists on reclosure the switch is again reclosed after tripping as before, but if the switch is again retripped after the second resetting, no further closure takes place as the weight has now reached its lowest position. An adjustable delay action mechanism may be inserted in the link 11 so that the restoration takes place only after a certain time interval.