GB1280257A - Multiple push-button tuning assembly - Google Patents

Abstract

1280257 Latch fastenings; stud and socket fastenings SCHOELLER & CO 14 April 1970 [15 April 1969] 17611/70 Headings E2A and E2B [Also in Divisions G1 H1 and H3] In a push button tuning assembly for television and wireless receivers having a push button unit with mutually cancelling push buttons, turning a sleeve 1 of a button effects wave range selection depressing both a shaft 5 and the sleeve 1 of the buttons, releasing and rotating the shaft 5 effects channel setting by means of a potentiometer arrangement 2 and wave range selection. The push button unit and the potentiometer arrangement 2 with a channel indicator 59, 60, form two separate unitary structures which are adapted to be assembled together and the shaft 5 have toothed rollers 6 which connect via gears 53 with the potentiometer spindles 55 to adjust the tuning. The potentiometer arrangement 2 is secured by straps 75 (Fig. 7) and twisted lugs 76 to the chassis of the push button unit. By rotating sleeve 1 the required cam 31 (see also Fig. 10, not shown) is selected and a ball catch 19 in a resilient plastics stop disc 17 holds the selected rotary position of the sleeve 1. A resilient hooked ring 22 retains the stop disc 17 rotatably in a face plate 21. When the shaft 5 and sleeve 1 of the button are pressed in surface 26 causes stopping and release bar 7 to slide transversely against a spring (28, Fig. 6, not shown), to release a previously pressed button and rim 27 engages the bar 7 which holds the sleeve 1 in. Spring 51 returns the shaft 5 even though the sleeve 1 is held in by the bar 7 and rim 27, so that the channel may be adjusted by driving the potentiometer via gear wheel 53 and the toothed roller 6 when the adjusting shaft 5 is rotated. Contacts 34 of the selected potentiometer 2 are switched by rim 32 and cam 31 moves the rocker 8 and contact slider 43 of a wave range switch 3 which may be of printed circuit construction. The channel set by the potentiometer 2 which may have a linear or logarthmic characteristic may be used to effect tuning via a variable capacitance diode. Indicator A pin 58 (Fig. 7) of the sliding contact of the potentiometer 2 engages in a groove 69 of a pointer lever 59 to indicate by a pointer 60 the channel selected by means of a channel indicator window 62. The pointer co-operates with a channel indicating scale 61 having teeth (66, Fig. 11, not shown) which engage grooves (15, Figs. 2, 3 and 10 not shown) in the sleeve 1 so that different scale is brought into view at window 62 in accordance with the rotary position of the sleeve 1. The mechanical indicator may be replaced by an electrical measuring instrument.