GB1133953A - Improvements in or relating to sound reproducing apparatus - Google Patents

Abstract

1,133,953. Automatic record changers. S. KOROBUK Ltd. 18 May, 1967 [19 April, 1966], No. 44227/65. Heading G5R. Trigger 43, Fig. 1, is depressed by the edge of a 10-inch record, thus permitting compression spring 63 to swing lever 40 counterclockwise until lug 46 reaches stop 53, at which stage the record has passed beyond trigger 43. Link 62 has been forced downwards by spring 63 during this movement, in consequence of which bellcrank lever 57 is rotated counterclockwise about its pivot 58; arm 59 of the bell-crank lever 57 pushes against a stop arm 34, Figs. 1 and 2, to rotate it about its pivot 56, Figs. 1 and 2, in a counterclockwise direction as viewed in Fig. 2. This movement of stop arm 34 places a stop surface 35, Fig. 2, in the path of a pin 37, the pin 37 forming part of a pin-and-slot connection between an arm 23 and an arm 26; the arms 23 and 26 form part of a known mechanism for swinging a pick-up arm 14 outwards and then inwards during lowering of a record- (not shown) from a stack (not shown). The placing of stop surface 35, referred to above, ensures that a pin 29, Figs. 1 and 2, extending downwards from the pick-up arm 14, will enter an appropriate one of three grooves 28 in a quadrant 27 secured to the arm 26, during the part of the cycle before the pick-up 13 is lowered on to the record, thus positioning pick-up 13 correctly for the edge of a 10-inch record during completion of the cycle. With a 12-inch record, trigger 43 is depressed, and contact between the record and the trigger is maintained until lug 46 rides beyond stop 53, permitting further counterclockwise rotation than before of bell-crank lever 57 and of stop arm 34, thus placing stop surface 36, Fig. 2, in the path of pin 37. Pin 29 thus enters a different one of the grooves 28. With a 7-inch record, trigger 43 is not contacted, so that bell-crank lever 57 is not moved, and in consequence stop arm 34 remains clear of pin 37, and pin 29 can enter a third one of the grooves 28.