GB1094133A - Improvements in electrical switching apparatus - Google Patents

Abstract

1,094,133. Switches held set and freed mechanically; press-button retractive switches. BURGESS PRODUCTS CO. Ltd. Feb. 11, 1965 [Feb. 17, 1964], No. 6483/64. Heading H2B. Press-button switches 54 of the kind described with reference to Figs. 1 to 10 in Specification 1,000,578 are each provided with a lever 87 extending through a slot 55 into a shallow box-section interlock assembly 90 on which the switches are mounted by screws 79. A latch plate 93, resiliently urged to the left by means not shown, has apertures 104 shaped to provide a camming surface 107 and a latching recess 109 for each lever 87, such that when a switch is operated the lever 87 moves plate 93 to the right and then becomes locked in position 87B thereby maintaining the switch in actuated condition. Operation of any switch thus also releases any previously latched switches. To prevent operation of more than one switch at a time bell-shaped plates 94 are arranged contiguously and pivotable about their top ends 96 such that any lever 87 pivots all the plates 94 when in actuated position 87B and thus prevents movement of any other lever 87 beyond position 88C which is insufficient for operation of the associated switch contacts. In a modification, the latch plate 93 may be omitted to provide a bank of retractive switches in which simultaneous operation of any two is prevented. In a further modification (Fig. 5, not shown) the members 94 are omitted and the slots in the latch plate are purely rectangular with individual spring-loaded latching pawls 118 pivoted on the latch plate such that switches are latched in the operated condition without moving the latch plate. In this embodiment a special " cancel " switch is provided at one end having an associated slot shaped as in Fig. 3 but without the latching recess 109. Operation of this switch then cams the latch plate to release all other previously latched switches.