GB551761A - Tuning mechanism for wireless apparatus - Google Patents

Abstract

551,761. Radio receivers. PHILCO RADIO & TELEVISION CORPORATION. Sept. 5, 1941, No. 11372. Convention date, Sept. 6, 1940. [Class 37] [Also in Group XL] A push-button tuning arrangement comprises a set of plungers 92 depression of which moves an operating bar 30 a predetermined distance according to the setting of threaded operating rods 57 which engage the edge of bar 30 and which are adjustable by means of milled wheels 91 accessible through slots in the individual pressbuttons. Bar 30 carries pins 46, 47 which engage crossed levers 34, 35 (dotted on Fig. 4) pivoted at 36, 37 the free ends of which operatively engage a bar 22 of a slidable frame 21, 22, 23 to the member 21 of which are attached by members 19, the movable cores 17 of permeability tuning coils 16. Movement of the frame 21, 22, 23 is assisted by an electromagnet 67 which is energized by a switch 72 by movement of the locking bar 59, a depression of any button, a second pair of contacts on the switch serving to mate the receiver during tuning. The central push-button is used for manual tuning and in this case the tuning knob 95 is mounted directly on the adjusting means for threaded operating rod 57. A pin 54 on link 35 abuts a cam surface 103 on a pivoted link 96 to move a pointer 99 having an index 105 movable over a scale (not shown) carried on a bracket 106. Fig. 20 shows an arrangement in which push-button 108 serves for automatic tuning and button 109 for manual tuning as previously described. A further button 110 has a knob connected by a flexible shaft 112 to a volume control 111 while the shaft is formed with a lug 114 for engaging an on and off switch 113. The arrangement is such that depression of 110 de-energizes the set. Operation of another button releases 110 to energize the set and allow 110 to be used for volume control.