Patent GB-509621-A (GB)
Title: Improvements in and relating to gramophones and like sound reproducing apparatus
IPC: G11B25/04
Filed: 1938-01-27
Abstract: 509,621. Gramophones ; coin-freed apparatus; photo-electric control. SPINKS, L. Jan. 27, 1938, No. 2599. [Class 40 (ii)] [Also in Groups XVIII and XL] Relates to gramophones for playing a record for reproducing a series of " slogans " or the like at intervals, e.g. for advertising purposes, means being provided for returning the tone-arm to its original position after the completion of the playing of the record. According to the invention, the turntable of the gramophone is geared to an auxiliary control shaft, a complete revolution of which occurs during the playing of the whole record, the shaft carrying a cam for controlling the traverse of the tone-arm and allowing the return of the tone-arm at the end of a revolution of the control shaft, the said shaft also being provided with a cam having a number of surfaces, each of which is adapted to determine the duration of a period of rotation of the turntable. In the construction shown in Figs. 1, 3 and 4, the turntable spindle 2, driven by a spring motor 3, is geared by a worm and wheel 7, 8 to a shaft 9 which controls the movement of. the tone-arm 20 across the record and its return, one revolution of the shaft 9 occurring during a complete reproduction from the record. A helical cam 10, Fig. 4, on the shaft 9 is engaged by a finger 11 on a lever 12 which is linked to a quadrant 16, pivoted at 15 and having a cam surface 17 against which a roller 18 on an arm 19 secured to the tone-arm is drawn by a spring 22. The cam 17, rotated by movement of the lever 12, positively controls the movement of the tone-arm, which after the reproduction of each slogan is retained in the correct position for the next operation of the machine by the engagement 'of the parts 17, 18. On the completion of the record, the cam 10 allows a sudden return of the lever 12 and cam 17, under the action of a spring 23, and thus the spring 22 is enabled to return the tone-arm to the initial position. The operation of the machine is effected by actuation, by means of a handle 25<1>, Fig. 3, of a coin-controlled spindle 25. The spindle carries an arm 96 bearing a pawl 95 which is adapted to rotate a threetoothed ratchet-wheel 26, engaged by a roller 27 on a sliding bar 28, which is normally locked by a bolt 29. When the insertion of a coin causes withdrawal of the bolt, as subsequently described, a single oscillation of the handle can be effected, and by the consequent rotation of the ratchet-wheel 26 the driving spring of the motor 3 is wound up. At the same time, during the movement of the handle 25' in the direction of the arrow, Fig. 3, a pin 35 on the bar 28 swings a U-shaped lever 36, causing it to move a slide 42 from left to right, Fig. 4. The slide carries a rack 45, which, by rotating a pinion 46 loose on the turn-table spindle, causes the pinion to rise under the action of a cam and to lift the turn-table so as to bring the record into engagement with the needle. This movement of the slide removes a brake 52, carried thereby, from engagement with the turn-table, and also shifts a stop 43 away from a co-operating stop on . the turn-table. An auxiliary stop 74, operated by the lever 36, comes into action, however, to ensure that a full to-and-fro movement of the operating handle is made before the turn-table is released. The slide 42 is locked at the end of its movement from left to right, by means of a detent (not shown) coacting with a link connected to the slide. This detent is controlled by a system of levers, one of which has a pawlshaped end engaging with a cam or ratchetwheel on the control shaft 9. At the end of the reproduction of a recorded slogan, the ratchet-wheel causes the pawl lever to trip the detent, thereby releasing the slide 42, which is returned by a spring 51 to its initial position. During the return movement, the slide effects the lowering of the turntable, and finally stops it by means of the members 52, 43. The machine is then ready for reproduction of the next portion of the record when the operating handle is again moved after insertion of another coin. Coin action. The coin, dropped down a shoot 93, Fig. 1, rocks a lever 91 and thereby tilts a catch 89, disengaging it from a gravity bar 86. The bar, which is connected by members 78, 77, 76 to the bolt 29, thereupon drops and withdraws the bolt from the bar 28. The spindle 25 is thus freed for operation as previously described. The bolt is restored to the locking position and the gravity bar raised, by the action of a lever 80 connected to the lever 36 and engaging the member 76. Before the parts of the mechanism have been restored to their initial positions on the completion of a slogan, the coin-slit is blocked by a plate 195 on the slide 42, Fig. 4. In a modification, Fig. 8, instead of a spring motor, an electromotor is provided for driving the gramophone, the motor being started and stopped under the control of a switch 111 operated by a lever 118. The coin-actuated mechanism is similar to that previously described, and comprises a gravity bar 112 connected to a pawl-ended lever 113 engaging a ratchet-wheel 116 on the control shaft 9. When, on the insertion of a coin, the bar 112 falls, the lever 113 rocks the lever 118, which closes the switch and is then held by a catch 122. In this construction, the turn-table remains in one and the same horizontal position, but the tonearm is automatically raised and lowered as necessary by the action of a lever 134 ; this lever, which is linked at 135 to the tone-arm, is rocked as required by engagement with a toothed wheel 131 on the shaft 9. At the end of the reproduction of each slogan, a lever 126 engaging the ratchet-wheel 116 is allowed thereby to rotate and to shift the catch 122 so as to release the lever 118, whereupon a spring 136 effects the opening of the switch. The bar 112 has meanwhile been reset by the action of the wheel 116 on the lever 113. The coin-freed mechanism controlling the gramophone may also be adapted for simultaneously delivering commodities. Instead of providing a coin-release device, the motor switch may be actuated by hand, or by mechanism controlled by a light-sensitive cell, e.g. by interruption of a light beam, or under the control of an electric clock.