GB680826A - Electric selector switch - Google Patents

Abstract

680,826. Retractive switches; snap-action switches. DEHN, S. G., (Globe-Union, Inc.) Dec. 8, 1949, No. 31556/49. Class 38 (v) A selector switch, Figs. 2, 3, comprises an insulating contact carrying, stator 27 secured to vertical ears 22 on a base 16. A spindle 32 supported by a further ear 23 on the base 16 and by a plate 18 staked thereto, carries a hub to which is fixed a contact-carrying rotor 33 and operating lever 39. To index the lever 39 in different positions or return it to a particular position from another position, a bell-crank lever 50 pivoted at 51 to the plate 18 and controlled by a spring 57 attached to a lug 58 on the plate 18, carries a roller 52 which co-operates with an internal cam surface in the body portion 36 of the lever 39. In Fig. 2 the cam surface comprises a central low part and two outer high parts 43, 44, whereby if the lever 39 is moved to either of its extreme positions corresponding to high part 43 or 44, and then released, it is returned to the central position by the spring 57 acting through the roller 52. By using the cam surface shewn in Fig. 9, the switch is retained when the lever 39 is moved counter-clockwise to an extreme position in which the roller 52 engages the low part between surfaces 63, 67, but is returned to the central position after being moved to the other extremity. In an alternative construction, Figs. 10, 11, a number of stator/rotor units may be spacedly mounted on bolts 81 supported by a plate 80, a single stator 27 being shewn. The switch is operated by a shaft 83 supported by a bearing 84 in the plate 80 and to which is fixed the rotor and an external surface cam 87. A lever 89 pivoted at 90 to the plate 80 carries a roller 88 urged by a spring 91 against the cam 87. In either extreme position when the roller engages the cam surface 97 or 98 and the operating force on the shaft 83 is released, the latter will be rotated until the roller occupies the low part 94 or 96. The switch may also be retained in the central position in which the roller occupies the low part 95. Alternatively, the cam parts, 94, 96 may be omitted in which case the switch is centralised by the spring 91, Fig. 12 (not shown).