Patent GB-370444-A (GB)
Title: Improvements in or relating to electrical control switchboards
IPC: H01H3/56
Filed: 1931-01-05
Abstract: 370,444. Automatic circuit-breakers. COATES, W. A., 165, Hale Road, Hale, Cheshire, FLURSCHEIM, C. H., Rushmoor, Fleet, Hampshire, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. Jan. 5, 1931, No. 402. [Class 38 (v).] Indicating.-A switchboard controller which indicates by a pointer or by its handle, the condition of a remote circuit-breaker which it electrically controls, has its circuit controlling part held to the handle if an automatic trip device on the circuit breaker is not actuated, but released therefrom upon the operation of the trip device. When the trip device is operated, a coil 22 on the switchboard controller, shown in Fig. 1, is energized to lift its plunger 21 and rotate a latch 16 about an arm 17 against the action of a spring 18. The latch 16 thus releases an arm 15 attached to a spindle 4 which carries a drum 2 on which is mounted a bridging contact 6 for controlling the closing and opening circuits of the remote circuit breaker, and the drum 2 is rotated under the action of a spring 20 to a position determined by the engagement of the arm 15 with an abutment 39, in which stationary contacts 7, 8 are open. If the remote circuitbreaker opens in response to the operation of its trip device a coil 27 is de-energized, so that a second latch 24 is rotated about its pivot by a spring 26, to release the arm 17 to allow a spring 29 to rotate the latch 16, and the handle 1, to a position determined by the engagement of the latch 16 with the abutment 39, in which the handle 1 is in the position AT. The latch 16 again engages the arm 15, and the remote circuit-breaker may be closed by returning the handle to the ON position. To open the circuit-breaker a button 32 is depressed to force downwards a rod 34, the bent end 35 of which rotates the latch 16, to free the drum 2 which moves to a position in which the contact 6 bridges a second pair of stationary contacts to energize the opening coil of the circuit-breaker. This position is determined by a fresh adjustment of the abutment 39, effected by means of the enlarged end 33 of the rod 34. When the circuit-breaker opens, the latch 24 is released and the handle 1 moves to a position determined by the new adjustment of the abutment 39 which is the HT position. Further rotation by hand of the handle 1, lifts a key 14, and places the handle in the LO position. In a modification, Figs. 3, 5 and 6, the contact carrying drum 52 of the switchboard controller carries a pointer 97, and the handle 51 is coupled to the drum by a catch 62 which can move axially in the bifurcated end of a rod 50 attached to the handle. In the "on" position of the controller shown, the shaped end of the catch 62 fits in a slot 76, Fig. 5, of a bush 75 attached to the drum. The bush 75, on its outer face, has an abutment 72 which fits into a slot 69 in a bush 66 attached by a pin 64 to the rod 50. There is a second abutment 71 made in the slot 69, and between the two abutments a spring 70 is compressed. A spring-pressed ball 85 holds the bush 66 and, therefore, the handle and the drum from rotation. When the automatic trip device on the circuit-breaker operates. and the circuit-breaker opens, a coil 80 is energized which, after a time interval, lifts a plunger 79 to raise the catch 62, and allow the spring 70 to rotate the drum and the pointer 97 to the AT position, Fig. 6, the position being determined by the engagement of a weighted pawl on the drum with a stop. To reclose the circuit-breaker, the handle 51 of the switchboard controller is moved anticlockwise until the catch 62 again engages the slot 76, when, the coil 80 being de-energized by the movement of the drum 62, the drum and handle may be returned to the ON position, the drum making appropriate connections for closing the remote circuit-breaker. The time delay on the coil 80 prevents the plunger from rising to lift the catch 52, and release the drum again before the circuit-breaker closes. To open the circuit-breaker by hand the handle 51, and with it the drum, are moved to the HT position where the drum makes appropriate connections for opening the remote circuit-breaker. At the same time the coil 80 is energized but the circuit-breaker opens before the plunger 79 can rise. Should the circuit-breaker fail to open in this interval, the plunger 79 rises to lift the catch 62 to release the drum 52 which moves' with its pointer to a position intermediate the positions ON, HT, indicating mal-operation of the apparatus. Specification 311,262, [Class 38 (v) Electric switches &c.), is referred to.