GB1087357A - Improvements in or relating to push button switches - Google Patents

Abstract

1,087,357. Keyboard switches. R. SCHADOW. Nov. 5, 1964 [Nov. 12, 1963], No. 45180/64. Heading H2B. In a switch comprising a bank of pushbuttons 15 with conventional interlock mechanism 4, 5, the outer or rest position of a button is determined by an abutment 9b on the slider 2 engaging a removable stop 12 which passes through a slot in the slider 2 and seats in a slot between lugs 13 on the main frame 1. Stop 12 is retained in position beneath the end of contact-carrying plate 6 by button-return spring 14 and is readily removable to allow the slider to be withdrawn from the button end for replacement or cleaning of contacts. In the embodiment of Figures 5 and 5a (not shown) the stop 12 passes through slots in plate 6, slider 2 and base 1, and is retained by twisting its projecting lower end (12d). Figs. 6 to 8 (not shown) illustrate an embodiment wherein a U-shaped end member (21) embraces the front of the main frame (18) and after withdrawal allows the slider (16) to be lifted to clear a shoulder (20) for removal. In the embodiment of Fig. 9 (not shown), a plate (19) of insulating material is retained in position by the U-shaped end member (21) and normally prevents complete withdrawal of the slider by engagement with an abutment thereon. In a further embodiment (Figs. 10 to 12, not shown) an inverted U-link (26) has its legs passing down through apertures in the contact plate (6) to act both as a stop to the slider (16) and as a conventional interlocking detent. The U-link may be retained by a leafspring (29b) extending from the end member (29) as in Figs. 10 and 11 (not shown) or by spring bias provided from the button-return spring 14 acting via a fulcrum (29d) on the end member (29) as in Fig. 12 (not shown). In the several embodiments of Figs. 6 to 12 (not shown) the spring clip moving contacts 10 are replaced by resilient bars (17).