GB1300947A - Improvements in or relating to electrical control devices - Google Patents

Abstract

1300947 Rotary switches; variable resistors CTS CORP 23 Sept 1969 [23 Sept 1968] 46818/69 Headings H1N and HIS [Also in Divisions F2 and H3] A control device has an actuator 23, 43 carrying a first contact 44, the actuator is biased to a neutral position by a resilient means 36 and when the actuator 23, 43 is moved in one direction from the neutral position by an applying force it first engages the first and second contacts 44,38, the second contact being constrained to move with a control member 34, 22, and then it operates the control member 34, 22 which performs a control function such as varying a resistance 17, 21 and on removing the applying force the actuator 23 is returned to its neutral position by the resilient means 36. On initial rotation of a shaft 23 by an applying force in either direction switch contact 44 on the actuator 23 contacts one of the contacts 38. Then continued rotation causes drive members 34, 22 to rotate adjusting the position of a slider 21 on a resistance film or wire wound track 17 of a variable resistor 11. On removal of the applying force the actuator 43 and shaft 23 are returned to the neutral position by a spring wire 36 and the switch contacts 38, 44 open but the position of the slider 21 remains unchanged. In a modification (Figs. 5-8, not shown), the actuator (144) is biased to its neutral position by a body of resilient material (135) mounted within a cavity (126b) in the control drive member (126). In a further modification (Fig. 9, not shown) the resilient material is replaced by a steel spring (235). The control device may be of rectilinear type. The variable resistance may be used in a radio or TV for volume control.