GB662586A - Improvements in or relating to switches suitable for use in electrically-driven gramophones - Google Patents

Abstract

662,586. Snap-action switches; retractive switches. PHILIPS ELECTRICAL, Ltd. July 22, 1949. [July 27, 1948] No. 19362/49. Class 38 (v). [Also in Group XXXVIII] A switch, Fig. 1, has its contacts 1, 2 carried by trifurcated blade springs 3, 4 each associated with an operating member 5, 6 respectively. The spring 3 is arranged so that movement of the member 5 from the broken line position into the full line position causes the spring 3 to "snap" down to close contacts 1, 2, and movement of the member 5 back to the broken line position enables the spring 3 to snap back to open the contacts 1, 2. The spring 4 is arranged so that movement of the member 6 causes the spring 4 to snap up to close the contacts, but the spring 4 does not snap back when the member 6 is moved back, so that the contacts 1, 2 remain closed in their upper position where the contact 1 abuts a stop 19. To open the switch, it is now necessary to move the member 5 to the broken line position causing the spring 3 to overpower the spring 4, so that both springs move downwards until the contact 2 abuts a stop 20, the contacts remaining closed. On the return movement of the member 5 the spring 3 snaps up whilst the spring 4 remains down, so that the contacts are opened. When the switch is used in an electric gramophone the spring 3 is actuated by a spring biassed pivoted support 21, Fig. 4, for the pick-up arm 22 and the spring 4 is controlled by a spring-biassed, manuallyoperated lever 27. Thus the contacts 1, 2 may be closer] and opened by lifting the arm 22 from the support 21 and replacing it thereon. The contacts may be closed with the arm on the support by operating the lever 27, but to reopen them it is necessary to raise and then lower the arm 22, the springs 3, 4 functioning in the manner described above. Specification 614,812 is referred to.