GB778981A - Improvements in or relating to tuning devices for use in radio receivers - Google Patents

Abstract

778,981. Adjusting radio apparatus. PHILIPS ELECTRICAL INDUSTRIES, Ltd. June 10, 1955 [June 15, 1954], No. 16749/55. Class 40(5) A push-button tuning mechanism for a radio receiver comprises a semi-circular disc 9 mounted in a stop within the shaft 3 of each push-button and adapted to be locked in place by a plate 17 having a bentup portion 19 which wedges the disc 9 against the inner surface of the slot when the push-button 1 occupies the position shown in Figs. 1 and 2, the plate 17 being fixed to one end of an inner shaft 21 sliding within the shaft 3 and having the pushbutton 1 secured to its other end, so that when the push-button is pulled outwards with respect to the shaft 3, Fig. 3, (not shown), the bent-up portion 19 is withdrawn from its wedging position and the disc 9 is free to rotate. Compression springs 25 and 31 are provided as shown, spring 31 being the stronger so that when the pushbutton 1 is subsequently depressed, the disc 9 is first brought into contact with the Luning-control member 11 and is positioned in accordance with the setting of the control member, further depression of the button 1 then causing the bent-up portion 19 to engage the disc 9 and lock it in position. The facing surfaces of the disc 9 and shaft 3 may be roughened, e.g. by the application of a layer of emery paper. The pushbutton comprises an extension 33 which slides in a slot in the front plate of the receiver and prevents the shaft 3 from rotating. The tuning-control member controls the position of the core or cores of one or more permeability-tuned inductance coils 15. Specification 649,360 is referred to.