GB663790A - Improvements in or relating to control mechanism for gramophone record playing apparatus - Google Patents

Abstract

663,790. Automatic gramophones. ELECTRIC & MUSICAL INDUSTRIES, Ltd. December 13, 1949. [March 11, 1949] No. 6730/49. Class 40 (ii). In a gramophone record playing apparatus, a control device such as for stopping and starting the turntable motor, or for initiating an automatic cycle in an automatic record changing mechanism, comprises a switch operating lever 6 which is latched in an operative or inoperative position by a latch 11, and an actuating member 14 moving with the pick-up arm 15 so that when the pick-up reaches a predetermined position or moves in the reverse direction, the actuating member 14 releases the latch 11 and the switch operating lever 6 is moved out of its latched position by the resilience of the switch blade 22. In the embodiment described the control member actuates a switch in the circuit of the turntable motor. During the outward movement of the pick-up arm 15, a pin 26 on the actuating member 14 moves the control member 6 against the action of switch blade 22 to a position in which the latch 11 retains the control member 6 by means of a tongue 9 thereon and a notch 10 and a spring 13 on the latch 11. This position of the switch operating lever 6 maintains a bladed switch 22, 23, in the closed-circuit position. When the stylus reaches the inner part of the record, a spring loaded pin 18 presses lightly on ratchet teeth 17 on the actuating member 14 until the stylus enters the eccentric run-off groove of the record. The resulting reverse movement of the actuating member 14 produces a clockwise movement of the latch 11 about a pivotal point 12, so that the switch operating lever 6 is released to open circuit the switch 22, 23. In the absence of an eccentric run-off groove, the latch 11 is tripped at a predetermined point by the pin 19 acting on an extension 27 of the switch operating lever 6.