GB320086A - Improvements relating to telephone instruments - Google Patents

Abstract

320,086. Siemens Bros. & Co., Ltd., Petithory, E. A., and Baker, F. July 3, 1928. Supporting. - In a telephone instrument in which two circuits are made in the later part of the movement of the receiver rest when the receiver is removed, the controlled spring contacts are definitely held in a certain position when the circuits are open and the associated controlling spring contact parts are operated directly or substantially directly by the short arm of the switch hook so as to make the circuits as nearly as possible simultaneously. Figs. 1 and 2 show a construction in which the springs 7, 10 are mounted in an insulating block 1 secured to the plate 2 which carries at its upper end a channel member 3 in which the bell crank end of the switch hook 5 is pivoted. An insulated roller 6 adapted to bear against the controlling spring 7 is mounted between the open ends of the horseshoe-shaped end of the switch hook. The spring 7, shaped as shown in Fig. 3, carries two contact points 8 and is provided with a hook to allow it to pass over the stop 9 which is provided to limit the travel of the controlled springs 10 and hold them in a definite position when the receiver is on the hook. When the receiver is removed, the hook moves from the dotted line position through approximately half its total travel before contact is made between springs 7 and 10 and, at the end of its travel, it and the associated parts assume the position shown in full lines. In the modification, Fig. 5, the controlled springs 10, 10<1> are mounted tandem fashion, the controlling spring 7 being of inverted J-shape and carrying contact points 8, 8<1> as shown. A long operating spring 11 is mounted in the block 1, exerts pressure along its length against spring 7 and bears at its upper end against roller 6. Springs 7, 11 have holes which permit them to pass over the stop for limiting the travel of the spring 10 and a corresponding stop 91 is provided for spring 10<1>. Specification 215,461 is referred to.