GB606458A - Improvements in and relating to gramophones - Google Patents

Abstract

606,458. Magazine gramophones. MORTIMER, E. W., and GARRARD ENGINEERING & MANUFACTURING CO., Ltd. Jan. 15, 1946, No. 1325. [Class 40 (ii)] In a magazine gramophone in which records are stacked about the turntable on a bent centre post, the edge of the records are supported by an inclined platform 7 having a displaceable section comprising a record-supporting part 15 with a feeding member 28 for use with one size of record, and a rigid section 14 with a feeding member 26 for use with a larger size record, the displaceable section , being movable to a position clear of the path of the records. The record-changing cycle is controlled by a rotary element 30, part of which comprises a gearwheel 32 driven by a pinion 13 on the turntablespindle 8 and having an interruption 33 in its periphery to effect disengagement from the pinion 13 during playing of a record. Engagement of the periphery of the gearwheel 32 with the pinion 13 is established at the end of a record by the movement of a trigger 35 (movable with the .pick-up arm) which engages a projection 34 on the gearwheel 32, and rotates the gearwheel 32 to provide an initial movement to bring the teeth of the gearwheel 32 and pinion 13 into mesh. To ensure meshing of the teeth without jarring, the leading teeth are formed on a radially movable spring-loaded plate 37, Fig. 7 (not shown). The upper surface of the rotary element 30 has a cam surface 39, Fig. 5 (not shown) to control the outward horizontal movement of the pick-up arm, by means of a roller 40 on a lever 41-42 which has a pin 43 at its other end adapted to engage a curved surface 44 on a lever 45 secured to the pick-up arm spindle. The lower surface of the rotary element 30 has a cam surface 53, Fig. 5 (not shown), to control the vertical movement of the pick-up arm, by means of a pin 54 on a bell-crank lever 55-56 which is linked by a member 57 to another bell-crank lever 58 controlling a vertical rod 59 which lifts the pickup arm. The turntable 1, which is driven by a motor 2 through a jockey-wheel 4, is mounted on a taper part 8a, Fig. 8 (not shown), of the hollow turntable-shaft 8. The records are carried on the step 6b of the bent stationary centre post 6 which passes through the hollow turntable-shaft 8. The displaceable section 13 of the platform 7 for supporting the smaller size records, is lowered under the control of levers 17, 23 and knob 24. A link 49 connected to the lever 23 sets the relative starting positions for the smaller and larger size records. The feeding members 26 and 28, which serve to unseat the lowest record of the stack from the step 6b at each revolution of the rotary element 30, are operated by a lever 27 connected to a member 6e having a slot engaged by a pin on the underside of the rotary element 30. When the last record of the stack has been lowered on to the turntable 1, the arm 129 drops and lifts the lever 78 so that the projection 83 is placed in the path of the lever 41. At the end of the playing of a record, the rotation of the element 30 is initiated in the usual way, and the lever 41 rides over the projection 83 where it is held back to enable a second cam surface 183 on the upper side of the rotary element 30 to engage it and thereby move the pick-up arm outwardly by an additional amount so that when the pick-up arm is lowered it rests on a plunger 70 which releases a switch-lever 64 held by a detent 65 on a bell-crank lever 66, and stops the motor.