GB645836A - Improvements in automatic record-disc changing gramophones - Google Patents

Abstract

645,836. Magazine gramophones. STAUBO, S. April 17, 1947, No. 10286. Convention date, Dec. 17, 1942. [Class 40 (ii)] In a magazine gramophone for playing both sides of records of mixed diameters, the record release mechanism and pick-up arm movements are controlled by a .cycling cam-member 15, which performs a half-revolution when brought into engagement with a continuously rotating shaft 11, the pick-up arm 29 being moved to play the underside of a record during one half-revolution, and the said record being released from the stack 6 and the pick-up arm 29 moved to play the upper side of the same record during the other half-revolution. The shaft 11 is carried by a frame 12 which is movable about the shaft 2 and is held by a spring-loaded arm 40 while a record is being played so that the driving wheel 13 is out of engagement with the cam-member 15. When the pick-up arm 29 reaches a certain point in its traverse, an arm 48 fixed to the pick-up arm spindle 28 pushes a spring-loaded retaining member 45 out of engagement with one of the stops 47 on a bar 41 pivotally mounted at the centre 16 of the cam-member 15. Under the influence of a spring 44, the bar 41 is thereby urged clockwise and the end 49 or 50 of the said bar 41 engages the wheel 13 and rotation of the cam-member 15 is initiated. Almost immediately one of the pins 21 on the bar 41 engages the spring-loaded arm 40 and releases the frame 12 so that the wheel 13 engages the periphery of the cam-member 15. At the conclusion of the cycle the wheel 13 rides up one of the inclines 51, 52 and the arm 40 re-engages the end 39 of the frame 12 so that drive between the wheel 13 and the cam-member 15 is interrupted until a further cycle is initiated. Control of the vertical movements of the pick-up arm 29 is effected by a cam 22 on the underside of the cam-member 15, said cam 22 acting through a lever 23, spring 26, arm 24 and rod 27. On the underside of cam-member 15 there is also a cam 17 which co-operates with a lever 18 which serves to release a record, by known means, on to the turn-table 3 at every other half-revolution of the cam-member 15. At the end of the playing of a record the pick-up arm is swung out beyond the edge of the records by means of one or other of the pins 37 which comes into contact with arm 48 fixed to the pick-up arm spindle 28. The same pin 37 later comes into contact with the arm 54, Fig. 4, of the lever 54-53 mounted beneath the motor board and leads the pick-up arm to a position over the plain part at the edge of the record, and is fed, after being lowered on to the record, into the start of the groove by a spring-loaded lever 55 at the end of the arm 54.