GB223010A - Improvements in or relating to adjusting devices, for wireless telegraphic and telephonic instruments and the like - Google Patents

Abstract

223,010. Chapman, A. H. Aug. 14, 1923. Variable-speed epicyclic gearing.-An adjusting-device for wireless instruments is arranged to drive the element to be adjusted either directly for coarse adjustment or through an epicyclic reduction gear for fine adjustment. In the form shown in Fig. 1, an arm 4 rigidly secured to the shaft 3 to be adjusted carries, a friction wheel 7 in rolling engagement with a fixed surface 8. A conical friction surface 9 carried by the adjusting knob 1 is adapted to engage the wheel 7 when a fine adjustment is desired, but on moving the knob axially against the action of a spring 16, the surface 9 is disengaged from the wheel, and a pin 5 enters one of a number of holes 6 in the boss of the arm 4, so that the knob may drive the shaft 3 directly for coarse adjustment. In a modification, Fig. 3, a second speed-reduction friction wheel 7a is mounted on the arm 4, and the conical surface 18 on the knob is brought into engagement therewith by depressing the knob against the spring 16. In this form, the knob in its normal position is directly connected to the shaft 3 through a conical clutch 19. In another modification, Fig. 4, the friction wheel 21 rolls round the inner periphery of a ring 22 supported from the panel 14. In this form toothed gearing may be substituted for the friction gearing, and an additional wheel may be provided between the wheel 21 and the driving member 2.