Patent GB-477325-A (GB)
Title: Improvements in and relating to automatic record-changing mechanism for gramophones or like talking machines
IPC: G11B17/10
Filed: 1936-04-24
Abstract: 477,325. Magazine gramophones. MANNING, W. F., FORTUNE, H. J., and GARRARD ENGINEERING & MANUFACTURING CO., Ltd. April 24,1936, No. 11693. [Class 40 (ii)] A magazine gramophone, in which the records are supported in stack formation above the turntable and are released in succession to fall thereon, is provided with record-changing mechanism for supporting and releasing records of different sizes arranged indiscriminately, and mechanism operatively associated therewith for positioning the pick-up arm in accordance with the diameter of the record deposited upon the turntable. The record-changing mechanism comprises three sets of oscillatable bell - crank members 19, 20, the arms of each being separated by an amount equal to the thickness of a record, in order that the uppermost arms 20, which are provided with knife-edge portions 22, may be inserted between the lowermost, record and the one above it, to support the stack while the members 19 are withdrawn during the transference of the lowermost record. The bell-crauk members are caused to oscillate by the rotation of a lever 18, one end of which carries a pin 58 which engages in an inclined groove 60 in the surface of a cylindrical cam 9 operated by trip mechanism such as is described in Specification 399,172. The end of the lever 18 remote from the pin 58 is provided with a toothed sector which engages a pinion on the shaft of one of the bell-crank members, the movement of which is transmitted to the other members by connecting levers 17, 16. The arms 19, 20 of the record-changing members are so disposed that in their extreme positions one of each pair lies outside the area of the largest record, and the other lies inside the area of the smallest record to be accommodated. When a record has been deposited upon the turntable, the pick-up arm 6 is caused to take up its correct position by an arm 10, secured thereto, the end of which engages one or other of two cam grooves 37, 38, Fig. 5, on the surface of the cylindrical cam 9, determined by the movement of a spring-controlled detector arm 24, as described in Specification 459,155. The entrance to the cam groove 37 is obstructed by a raised portion 39, whereby the end of the arm 10 is caused to enter the groove 38 when a 12" diameter record is to be played. When a 10" diameter record is deposited on the turntable, the inward movement of the arm 24, which is connected to a pivoted diverter member 33 by a lever 32, rotates the member 33 into a position in which the downturned end portion thereof closes the entrance to the groove 38, and the end of the lever 10 is forced to ride over the raised portion 39 and enter the groove 37. When it is desired to repeat the playing of a record, the control knob 46 is turned anticlockwise into the appropriate position, and a lever 47 connected thereto rotates a doublearmed lever 48, 49 in a clockwise direction. The arm 48 is thereby brought into contact with a pin 52 on the diverter member 33 and prevents movement of the pick-up arm, while the arm 49 rotates a spring-controlled lever 54 to cause the end 61 thereof to close the entrance of the groove 60 and prevent operation of the record-changing mechanism. To reject any particular record, the knob 46 is rotated in the opposite direction and the cam 9 is rotated, to operate the record-changing mechanism, by the release of a clutch lever operated by a pin 68 at the end of the lever arm 49, through a system of levers (not shown in Fig. 1). When the last record has been played, the arm 24 moves inwardly under the action of the spring 31 and engages with a pivoted catch 42 to trip the motor switch lever 43 and bring the machine to rest.