| 摘要 |
A presettable tuning system in particular for radio receivers, has a drum member 4 with potentiometer tuning members 5, 8, 9 mounted thereon; means for rotating stepwise the drum for putting in circuit each at a time the potentiometer tuning members upon actuation of a control member 10 (Figs. 3 a-c, 4 a,b) and means 23 for the presetting of said potentiometer tuning members for tuning with each of them a desired transmitting station. By pushing a key 10 (Figs. 3 a-c 4 a,b) a rack 10', gear 11 and ratchet 12 steps the drum to the next position. By pressing a knob 23 (Fig. 4 a,b) it moves outwardly and causes a conical gear 23' fastened to the knob 23 to engage with a conical gear 7 on a spindle 9 of a selected potentiometer 5, 8, 9 so that it can be adjusted to select the derived station. During tuning adjustment by knob 23 a lever 22 is urged by a spring 24 to prevent the key 10 from being pressed until the knob 23 is again pressed and returned at its inner position. <IMAGE> |
