GB672388A - Improvements in or relating to rotary electric switches - Google Patents

Abstract

672,388. Rotary switches. IGRANIC ELECTRIC CO., Ltd. March 10, 1950. [March 10, 1949] No. 6069/50. Class 38 (v). The switch comprises a rotatable, cylindrical, insulating contact carrier and an insulating base having walls forming a number of chambers each adapted to house a pair of spaced fixed contacts, the carrier having a peripheral flange movable in the chambers between the fixed contacts which are arranged to be bridged in turn by a contact located in the flange with its ends exposed on opposite sides thereof, the arrangement of the base, carrier and flange being such as to minimise arcing. In a single-pole arrangement, Fig. 3, the movable contact 35 is carried in an aperture 34c in the carrier 34, the flange 34b of which is guided between the adjacent surfaces of base sections 32, 37, the carrier being mounted on a square sleeve 27 surrounding part 15d of the operating spindle 15. The contact 35 is urged outwards by a spring 36 and is arranged to bridge such pairs of fixed contacts 38d, 41a as are provided, these contacts being mounted in base recesses 32g, 37b. Each contact 41a is an upturned lug of a contact ring 41 having a terminal lug 41d, Fig. 8, in one of the recesses, instead of a contact 41 so as to provide an "off" position, and each contact 38d forms part of a U-shaped member 38 having a terminal screw 38c. The unoccupied recesses are blocked off by flat plugs 39 to prevent the entry of dust. The spindle 15 has a flatted portion 15c carrying (a) a member 23 co-operating with a fixed stop 17b to limit rotation of the spindle and therefore the number of switch positions, (b) an eccentric cam 24, and (c) a member 25 having a downturned lug 25c. The cam 24 is enclosed by an annular member 26 having a downturned lug 26c engaging a slot 30a in a member 30 mounted on sleeve 27 and having an upturned lug 30b. A spring 29 surrounds the upper end of sleeve 27 and has its ends 29a, 29b brought out on opposite sides of lugs 25c, 30b. The spindle is retained in each operative position by the engagement of member 26 in recesses 31a in a stop plate 31 secured to the top of the base. When the spindle is rotated clockwise, the cam 24 causes member 26 to move radially inwards, the end 29a of the spring meanwhile being rotated clockwise by the lug 25c. When the member 26 is eventually freed from a recess 31a, the spring end 29b rotates plate 30, and thus the sleeve 27 and carrier 34 clockwise, until member 26 engages the next recess. If the contacts stick a part 25b on member 25 engages a part 26b of member 26 positively to drive the latter. The carrier 34 may house several contacts 35, and the ring 41 may have two terminals (Fig. 12, not shown), and in a modification, (Fig. 13, not shown), the ring may. be in two parts, each having a terminal. A multi-pole switch is constructed by using one or more intermediate base sections 40, Fig. 4, having upper and lower surfaces identical with those of portions 37, 32, respectively.