GB756473A - Improvements in or relating to radio receivers comprising a directional antenna - Google Patents

Abstract

756,473. Snap-action switches; switches held set and freed mechanically. PHILIPS ELECTRICAL .INDUSTRIES, Ltd. March 12, 1954 [March 17, 1953], No. 7297/54..Class 38(5) [Also in Group XL(c)] In a radio receiver, operation of a switch controlling the aerial connection in one direction is effected by rotation of a tuning control knob, operation in the other direction being alternatively effected by depression of a latching member or by rotation of a further control knob. In a first embodiment, Fig. 1, depression of a push button 21 causes the switch 1 to be changed over, the switch being held in this position by a projection 33 on a bell-crank lever engaging a projection 32 on the shaft 22. Simultaneously a toggle lever carrying a brake pad 31 snaps over under the action of a spring 30 and engages a flywheel 13. The flywheel 13 is formed upon a sleeve 6 which is normally rotated with the shaft 5 to which the tuning control knob 3 is attached, being coupled thereto by a pin 12 attached to the sleeve 5 and fitting within a V-shaped slot in the sleeve 6. When, however, the.push button 21 is in its depressed position and the flywheel 13 engaged by the brake pad 31, an attempt to rotate the knob 3 causes the pin 12 to ride up along the V-shaped slot thus causing the projecting end of the shaft 5 to project still further and disengagt the bell-crank lever from the catch 32, the push button 21 and the switch 1 being consequentially restored to their original positions. In a second embodiment, Fig. 2, two substantially identical rotary control systems are provided. With the apparatus in the position shown. rotation of the knob 3<SP>1</SP> initiates the operation of the spring loaded toggle device 40, thus changing over the switch 44, disengaging the braking pad 42 from the flywheel 13<SP>1</SP> and causing it to engage with the flywheel 13.