GB441851A - Improvements in or relating to wireless receiving or transmission apparatus - Google Patents

Abstract

441,851. Distant - control systems. COHN, E., 111, Prince's Park Avenue, Golders Green, London. July 20, 1934, No. 21306. [A Specification was laid open to inspection under Sect. 91 of the Acts, Feb. 19, 1935.] [Class 40 (i)] The tuning member of a wireless receiver or transmitter is controlled, in response to impulses from a dial or other impulse transmitter, by mechanism which imparts movement to the member through the medium, inter alia, of a rectilinear movement imparted to or derived from a cam. In the arrangements shown diagrammatically in Figs. 2 and 3, a cylinder 15 on a spindle connected to the spindle of a tuning condenser, has inclined or helical teeth 19 which form a ratchet wheel rotated by pawl 20 of magnet 13 to give a coarse adjustment of the spindle. One tooth acts as a cam to a member 22 carried by a rack 21 stepped by a pawl 21a of another magnet to effect a fine adjustment of the spindle, while a further member 25 engaging rack 21 is moved, to obtain a finer adjustment, by a cam 23 moved step-by-step by a further magnet. Final adjustment may be made by manually operated slow-motion mechanism. Distributing mechanism controlled by a dialling relay is provided to direct the impulse trains to the proper magnets, or a single magnet may be provided, the distributer acting through suitable levers and links to operate the requisite pawls. A wave change switch may also be controlled by an impulse train. The distributer shown in Figs. 6 and 7 comprises a ratchet wheel 28 stepped by a relay operated each time the dial is moved off normal so that one of the arms of a member 35 is moved successively over a series of tappets 31 mounted on a fixed member 30 and controlling levers 32 (as shown), for operating the various stepping pawls in turn or making circuits for the various magnets. As shown, all impulse trains operate magnet 13 which reciprocates the spindle 29 of member 35 so that the tappets are reciprocated in turn to operate the pawls. The first tappet may operate a wave change switch and the last tappet controls release whereby the mechanism is permitted to return to normal under spring control. The condenser spindle may be spring driven from the cylinder 15 and may have a hydraulic or governor - controlled brake. A modified distributer comprises a cam member carried by ratchet 28 and completing the circuits of separate stepping magnets in succession.