Patent GB-858141-A (GB)
Title: Improvements in or relating to contact spring-pile-ups for electrical switching devic es
IPC: H01H50/56
Filed: 1955-10-17
Abstract: 858,141. Contact-members for switches; multi-position switches; electromagnetic relays. ENGLISH TELEPHONE CO. Ltd., and HOYLES, L. Jan. 17, 1957 [Oct. 17, 1955], No. 29541/55. Class 38 (5). The blades 1 . . . 6 of a contact pile-up, Fig. 1, have side extensions with apertures 1<SP>1</SP> . . . 6<SP>1</SP> of non-circular e.g. square, shape and are separated by spacers 7 . . . 11 having raised portions 7<SP>1</SP> . . . 11<SP>1</SP> on their upper faces of similar shape to the apertures. The lower faces of the spacers have depressed portions (not shown) of a similar size and shape to the raised portions whereby the raised portion of each spacer extends through the aperture of the contact blade and into the depression of the spacer immediately above it. The assembly is held together by a single bolt passing through holes in the spacers and top and bottom washers 80, 30. As shown, the side extensions are disposed alternately to the left and right to form two change-over contact sets arranged sideby side, the moving springs 3, 4 having operating lugs 3<SP>11</SP>, 4<SP>11</SP> and the fixed springs 1, 2, 5, 6 being buffered by longitudinal extensions of the spacers 7, 8, 10, 11. An operating member for the springs 3, 4 comprises, Fig. 11, an insulating button 12 which is mounted between the two contact sets and has slots 12<SP>1</SP> receiving the lugs 311, 411, upward or downward movement of the button causing operation of the springs (Figs. 2-4, not shown). In a modification (not shown), the non-circular apertures in the contact blades are disposed centrally along the blade longitudinal axis in which case each blade is extended equally on either side to give space for the aperture, such an assembly resulting in a single contact set. The blades need not all project from the pile-up in the same direction but may be arranged at right-angles to each other if the apertures are square. Alternatively, by making the blade apertures in the shape of an 8-pointed star and retaining the squareshaped elevations and depressions on the spacers, there are eight 45-degree spaced positions for each blade. In a lever key switch, Fig. 5, four pile-ups as in Fig. 1 are arranged in two pairs side-by-side (only one pair shown), each pair being secured by a single bolt 13 together with blades 22 for operation of the buttons 12 by a roller 23 on the key 19. The key remains in the position to which it is moved, a lamp 24 indicating the switching operation. The pile-up or pile-ups may be alternatively operated by a push-button, a rotating arm, or a ratchet and pawl drive (Figs. 7-10, not shown). In an alternative mounting for the blades (Figs. 12, 12a, not shown), the insulating spacers do not have the elevations and depressions but have non-circular apertures similar to those in the blades, and the blades and spacers are fitted over an insulating bush of corresponding cross-section which extends right through the pile-up. In Figs. 13, 14 (not shown), a telephone-type relay includes two of the pile-ups of Fig. 1 arranged side-by-side on the relay yoke.