GB523508A - Improvements in devices for tuning radio receivers - Google Patents

Abstract

523,508. Stopping shafts in predetermined positions ; securing discs on shafts. YARDENY, M. Jan. 10, 1939, No. 796. Convention date, Jan. 13, 1938. [Class 80 (ii)] [Also in Group XXXVI] A mechanical push-button tuning system comprises a plurality of discs 5, one for each required station, each individually and freely rotatable, until fixed for its corresponding station, on the shaft 8, to which the tuning condenser spindle is secured by screw 9. Each wheel 5 is fixed, after calibration, to a disc 10 by means of screw clamps 15, and has a semi-circular notch adapted to be engaged by an abutment 19a of a spring loaded plate 19. normally held out of engagement with its wheel 5 by a member 32 on each push-button 17 when undepressed, as shown. The shaft 8 is fixed to the operating disc 10 by screw 12 and is connected to the tuning dial through a clutch device comprising a retractable stud 43 carried by a sliding spindle 40, the latter being retained in the uncoupled position by levers 45 pivoting about 46 to engage the end of shaft 8. A spring-operated slow resetting-device comprises a spring 48 secured to shaft 8 and the toothed casing 49 rotated by the operating disc 10, the gear train 50, 51 and air brake 52 acting as a retarding device. To operate the apparatus, the disc 10 is rotated clockwise by the finger-aperture 11, Fig. 1, winding-up spring 48, until the discs are stopped by the fixed rod 37 engaging the extremity of a semi-circular slot in the disc. The desired station button is then depressed and the apparatus is rotated with shaft 8 by engagement of pawl 53 with the wheel 49 until the abutment 19a corresponding to the selected button, arrests the device. A general release button 34 releases all depressed buttons by means of the usual latch - bar mechanism.