GB612788A - Improvements in or relating to devices for tuning radio-apparatus - Google Patents

Abstract

612,788. Indicating-apparatus. PHILIPS LAMPS, Ltd. June 4, 1946, No. 16947. Convention date, April 22, 1942. [Class 40 (v)] A radio timing device comprises a scale, knob and pointer which are mounted so as to be easily detachable from the housing of the tuning component and in which the tuning component and the pointer have their extreme movements limited independently by stops, so that when the pointer is in contact with one stop, the wavelength indicated corresponds to the corresponding extreme position of the tuning component, the knob being connected to the pointer through a slipping coupling. In the Figure, the slipping coupling is comprised by a cord 11 and the movement of the pointer 2 is limited by stops 13 and 14, one of which is preferably adjustable. Coupling between the two parts of the driving shaft 7 of worm gear 6 and of condenser 5 is made by means of a claw-coupling 10, thus enabling the front plate 1 with the components mounted on it to be removed and access easily obtained to the rest of the apparatus. For adjustment of the pointer relative to the shaft of the tuning component after replacement of the front plate, the tuning component is rotated to one of its extreme positions and the knob further rotated with the cord 11 slipping until the pointer abuts the corresponding stop. The path which the pointer can traverse between its two stops should preferably be made equal to that corresponding to the difference between the extreme positions of the tuning member.