Patent GB-240234-A (GB)
Title: Improvements in disc type talking machines
IPC: G11B17/00
Filed: 1924-06-26
Abstract: 240,234. York, R. H. June 26, 1924. Multiple machines.-Relates to gramophones of the kind in which a number of turntables are mounted on a rotary carrier, and are successively brought into the playing position in relation to a sound-box and tone-arm, step-bystep movement of the carrier occurring automatically each time the pLaying of a record is completed. According to the invention, the carrier is mounted for rotation in an inclined plane, and the axes of the turntables, symmetrically disposed around the carrier, are equally inclined relatively to the carrier in planes tangential thereto. With this arrangement, each turntable lies horizontally on reaching the playing position, where it is rotated by a motor, the carrier being there fixed. In the machine shown, eight turntables 40 .. 47 are arranged as described above on a carrier ring 32, which is mounted on ball bearings on a tilted support 39. The carrier tends to rotate, under the action of a spring motor 27, but it is normally held by an electromagnetic catch 33, Fig. 5, in the path of the turntable bearings 36. One of the turntables (40, as shown) is then in position for the record thereon to be played by the soundbox 68. The lower end 54 of each turntable spindle is pointed, and that one in the playing position rests on a ramp, not shown, which affords a support. The end of the spindle and the ramp also form electric contacts in the circuit of the electromagnet 35 by which the catch 33 is controlled. Driving turntables.-Within the ring 32, and above the spring motor 27, is an electromotor 25, which drives, through a friction pinion 50, a spindle 49. The spindle carries a rubber collar 48, adapted to make frictional driving contact with the edge of that turntable which for the time being is in the horizontal position. Raising, positioning, and lowering sound-box.- Projecting from a U-piece 66 which carries the sound-box and which is rotatably mounted as usual on the end of the tone-arm 65, Fig. 12, are levers 71, 72. A stop finger 79 depends from the junction sleeve 67 of the tone-arm. The lever 72 has pivoted on it an arm 73, the forward end of which is provided with a stop 75, and the rear end 76 working in a slot 77 in a plate depending from the tone-arm. To the upper end of the lever 71 is connected a cord 83, which passes over and through the tone-arm and being guided round buttons 85, 86 on the tone-arm and its socket, is fastened to a lever 87, Figs. 10 and 11. A cord 97 also extends from the lever 87, and, passing round the button 86, is fixed to a screw 98 on the tone-arm. The lever 87 is fixed to the same rocking spindle as an arm 91, which is connected to a dash-pot 94. The functioning of the abovedescribed mechanism is as follows. When the playing of a record is completed, the reproducing needle touches an adjustable contact arm 99 mounted on the turntable spindle, thus completing a circuit through the magnet 35. The catch 33 is thereupon moved, allowing the carrier ring 32 to be rotated by the spring motor. The rotation is stopped, however, as soon as the next turntable 41 is in the playing position, since the withdrawal of the. catch 33 from its operative position is only momentary, on account of the breaking of the magnet circuit soon after it has been made, by the descent of the table 40. As the turntable 41 descends to the playing level, its edge engages the finger 79 for a time causing the tone-arm to swing back. Meanwhile, a bracket 38<x>, Fig. 11, projecting from the ring 32, has run up the arm 91, forcing it down under the control of the dashpot. The conse quent tautening of the cords 83, 97 causes the tone-arm and the sound-box to move to such a position that the needle is correctly placed over the starting-point on the record the stop 75 assisting in the control of the sound-box by engaging the edge of the record. The lowering of the sound-box to place the needle on the record finally occurs when the arm 38<x> allows the lever 91 to rise and slacken the cords 83, 97, and at the same time the stop 75 is lifted from the record by reason of the movement of the end of the lever 73 in the slot 77. The catch 33 may be operated from a distance, by means of a cord; and the motor 25 may also be started and stopped from a distance. The arrangement of the tone-arm and motor relatively to the turntables may be different from that shown. The Provisional Specification describes various modifications in details, particularly as regards the means for driving the, turntables and for rotating the turntable carrier.