GB514060A - Improvements in adjusting or selecting mechanism for the tuning controls of wirelessapparatus - Google Patents

Abstract

514,060. Radio receiving sets. PLESSEY CO., Ltd., PACKMAN, P. J., and MORRISON, P. H. April 23, 1938, No. 12230. [Class 40 (v)] [Also in Groups XXXVIII and XXXVI] In a push button system for controlling the tuning of radio sets, each button is allocated to predetermined positions of both the tuning device and the wave range switch. The tuning device and the wave range switch are driven by a common motor 12, Fig. 5, under the control of selector switches A, B the stationary contacts 25, 70 of which are connected to the push buttons 80 ... 84. Groups of buttons, 80, 81 correspond to the long and medium wave bands respectively and the keys 82, 83, 84: effect selection of short waves, very short waves and gramophone reproduction. When a key in a group 80 or 81 is operated, a circuit for the motor 12 is closed over one or other contact 64 or 65 of the switch B and the motor is driven in one or other direction to position the waverange switch until the circuit is broken by the insulating gap 66. The switch A associated with the tuning condenser is rendered ineffective by a switch 73 ... 76 operated by one or other of the clutch magnets 49, 50 which is operated over the contacts of switch B to clutch the switch to the motor. When the wave-range switch is correctly positioned, the clutch is released and the switch 73 ... 76 places the motor 12 under the control of the switch A which is then positioned in accordance with the operated key. The switch A is driven through friction gearing and the contacts 25 are adjustably mounted on supporting frames. Specification 454,735, [Group XXXVII], is referred to. The Provisional Specification also refers to Specification 501,273, [Group XXXVIII]. Reference has been directed by the Comptroller to Specification 197,774.