GB1083518A - A latching push-button electric switch - Google Patents

Abstract

1,083,518. Switches held set and freed mechanically; lampholder. CUTLER HAMMER Inc. April 15, 1966 [April 16, 1965], No. 16583/66. Headings H2B and H2E. A latching push-button switch comprises a slidably mounted hollow insulating plunger 22 carrying a disc contact 10 and a nylon latch 32, and a plastics rectangular base 2 having a central cavity 2a to receive the plunger and mounting fixed contacts 6, (8, Fig. 2), and a resilient latch hook 34. On initial depression and release of the plunger, latch 32 co-operates with hook 34 to retain the plunger in a latched position, and on further depression and release, the plunger is released for return to its original position by a helical spring 12. In Fig. 1, contact 10 slidably engages and bridges contacts 6, (8) when the plunger is in its latched position, whereas in a modification, the fixed contacts are as shown in Fig. 8, Specification 952,913, and are bridged when the plunger is unlatched. Base 2 (Fig. 4), has diametrically opposed holes 2b, (2e) containing contacts 6, (8) and further holes (2c, Fig. 2), 2d containing fixed contacts 14, 16 providing a circuit for a fixed indicator lamp 20 mounted in plunger 22 beneath a translucent disc 26. Hook 34 is held fixed in base 2 by a plug 36 (Fig. 3). Base 2 is closed by a metal cover 4 provided with a mounting bushing 4a and having integral straps bent into grooves (2g, Fig. 4) 2n in the base. Insulating retainers 28, 30 hold contacts 6, (8), (14), 16 in position, and the ends of contacts 6 (8) are inserted in slots 2f in the base. Plunger 22 (Fig. 5) comprises an upper tubular portion 22a and a lower hollow rectangular portion 22b in the base cavity 2a slotted diagonally at 22c (Fig. 2) for the clearance of contacts 14, 16 when depressed. A slot (22e, Fig. 5) in the plunger rigidly mounts latch 32 (Fig. 6), lug (32a) air latch 32 fitting in notch (22d) in plunger 22 and portions (22f) in plunger 22 fitting in grooves (32b) in latch 32 so that a cam face on the latch faces inside the plunger. On initial depression and release of the plunger, the free point of hook 34, which is normally biased against wall (32m) of cam face of latch, is guided along walls (32c, d, e, f, i, n, p, Fig. 6) of latch 32, the plunger being latched when point 34 is against wall (32p), and on repeated depression and release, the point of hook 34 is guided along walls (32n, j, k, m) of latch 32, thus completing a generally heart-shaped path. Contact 10 (Fig. 5) has a slot (10b) to provide clearance for the free point of hook 34. An internallythreaded lampholder 18 has terminals 14, 16 supporting the lampholder in a base 2 containing a switch. Terminals 14, 16 are clamped by a rivet passing through an enlarged hole in terminal 14 and an enlarged hole in the base of holder 18. Terminal 16, electrically connected to the rivet, is clamped between the rivet head and an external insulating washer; and terminal 14, electrically connected to the holder 18, is clamped between the external washer and the holder 18, an insulating internal washer also being provided.