GB1254636A - An electrical selector switch - Google Patents

Abstract

1,254,636. Tuning selector arrangements. INTERNATIONAL STANDARD ELECTRIC CORP. 30 April, 1969 [4 May, 1968], No. 21957/69. Addition to 1,243,638. Heading H3Q. [Also in Division H1] A selector switch as claimed in claim 1 of parent Specification 1,243,638, includes a further switch 14 having a plurality of switch positions adapted to be operated by a plurality of presettable operating devices 5, each operating device 5 being adjustable to one of its preset conditions to operate the further switch to one of its positions when the control knob 3 of the selector is operated to a respective one of its switching positions. The control knob 3 has a disc 9 attached at one end with injection moulded bearing bushes 11 spaced in a ring around the disc 9. Square cross-section cams 5 each with a projecting pin 13 are mounted in these bearing bushes 11. The pin 13 operates a waveband switch 14 by moving a slide carrying contacts which engage fixed contacts 16 printed on to an insulating support 18. When the control knob 3 is in one of its six stable positions as determined by a detent mechanism 24, the cam 5 associated with this position, can be adjusted by pressing and rotating switch adjuster knob 7 so that the wave range switch is adjusted by altering the position of the pin 13. The associated tuning means 2 may be adjusted by pressing and rotating circuit adjuster knob 4 which adjusts the potentiometer spindle 29 of the tuning means. Six of these potentiometers are provided one for each stable position of the control knob 3, a printed circuit resistance track (19, Fig. 5, not shown), being provided for each potentiometer. The contacts attached to the wave range switch slider 15 may be contact springs (Figs. 8 and 9, not shown). Pointer type dials may be coupled to the spindle type potentiometer 29. The frequency range set by the wave range switch 14 may be indicated by channel numbers marked on a transparent plate fixed to the slider 15 of the switch 14 and visible through windows 30 on a front panel 31 just above the pointers of the spindle type potentiometer.