GB356753A - Improvements in or relating to snap action electric switches - Google Patents

Abstract

356,753. Tumbler switches. IGRANIC ELECTRIC CO., Ltd., 147, Queen Victoria Street, London.-(Cutler-Hammer Manufacturing Co. ; Milwaukee, Wisconsin, U.S.A.) June 6, 1930, No. 17621. [Class 38 (v).] A tumbler switch of the toggle type has a moving contact element carried by a U-shaped yoke pivoted about a transverse axis by virtue of integral lateral projections engaging openings in a fixed casing. One form of switch is shown in Figs. 1 and 3. The insulating base has a central recess 32 and two long recesses 20, 21. Fixed contact springs 38 are inserted in the recesses 20, 21 so as to be strained between abutments 24, 25, 36 leaving two spring tongues 40 projecting into the central recess. Current leads 47 are inserted through holes in the bent round ends of the contact springs and are soldered in the usual way. A cover-plate 56 is clamped on to the base and carries in a central aperture a bushing 64 which carries the operating lever 65. An insulating plate 54 is inserted between the base and the cover. The movable contactmember comprises a U-shaped stirrup having the limits turned outwards at the ends to engage holes in the bushing 64 so as to pivot about an axis which is below and parallel to the pivot pin 66 of the dolly. A rivet 76 through the bottom part 74 of the contact-member carries a circular contact disc 84 mounted so as to rotate freely between two insulating discs. The head of the rivet 76 serves as an abutment for the lower end of a dead-centre compression spring, the upper end of which carries a dished plate on which bears the lower end of the dolly. The contact disc in the position shown in Fig. 1 is adapted to bridge the springs 40. In the off position the disc bears against the end surface 34 of the recess 32. Nuts 86, 87 are provided on the bushing 64 for securing the switch to a panel. Fig. 6 shows a modification in which the dolly 103 is carried by a spindle 98 mounted in a bushing 94 and operated by a knob 100. In another modification a disc is inserted in the bushing underneath the dolly and having a slot through which the lower part of the dolly passes, thus limiting its movement and acting as a guide. Modifications are described comprising two-way switches and embodying fixed contact springs of different shapes. Reference has been directed by the Comptroller to Specification 336,098, [Class 38 (v), Electric switches &c.].