Patent GB-513216-A (GB)
Title: Improvements in and relating to automatic record changing mechanism for gramophones or talking machines and the like
IPC: G11B17/16
Filed: 1938-03-31
Abstract: 513,216. Magazine gramophones. WILLIAMS, F. H. and GARRARD ENGINEERING & MANUFACTURING CO., Ltd. March 31, 1938, No. 9904. [Class 40 (ii)] In a magazine gramophone, the records are supported in a pile above the turntable by resting upon the extremity of a post or like member' and upon means which engage the edge of the records, and are released singly, for playing, by means which engage the edge of the lowest record and by which the record is displaced laterally so that the central hole passes over the supporting post or the like. The records 3, which may be stacked in any order irrespective of size, are, in the machine shown, supported partly by a bent post 4, removably and non-rotatably extending 'through a sleeve which carries the turntable and engaging with the lowest record at a point spaced from the central hole. The lateral support for the records comprises a platform 5, cut away centrally at 7, Fig. 2, and having a a pair of upwardly extending pins 8, which serve to locate the records. A fixed rod 19, within the opening 7, carries a series of plates 20, slidable as a unit upon the rod, each plate being formed with lugs 21, and a recess within which is fixed a spring 22. The springs are so formed and arranged that the edges of the records when inserted in the recesses between the plates are frictionally held. To release the records in turn from the pile there is provided a pair of rotatable arms 9, mounted on vertical spindles 10, the arms being geared together for movement in unison by toothed quadrants 11. One of the spindles 10 has an arm 12 linked to a cam-follower 14 engaging in a groove 15 in a rotary cam 16. When the cam is rotated both arms are simultaneously given an inward movement and then returned. (Fig. 2, for convenience, shows one arm :9 at rest and the other displacing a record). During the inward movement of the arms, their flat ends 17 pass beneath the edge of the lowest record in the pile, which is resting on the platform 5. Abutments 18, on the arms 9, engage the edge of the record, and displace it until the central hole engages the end of the post 4, and the record falls down to the turntable. The remaining records are held against displacement by the frictional grip of the springs 22. As the arms 9 move into the record-displacing position, lugs 23 thereon pass under the plates 20 and .support them, and when the arms return to the rest position the lugs move clear of the plates 20, allowing them to move downwardly until the record which is then lowest rests on the platform 5. Means are provided, Figs. 4 and 5 (not shown), for automatically controlling the setting of the pick-up arm or tone-arm in accordance with the size of the record which is being released for playing. For this purpose, the pick-up arm is controlled by an arm having a cam-follower adapted to track in one or other of two grooves in a rotary cam, these grooves determining the respective settings of the pick-up arm, by means such as are described in Specification 459,155. The cam follower is diverted into the requisite groove by mechanism which is controlled by a detector in the form of a spring plunger on one of the record-displacing arms 9. The plunger is engaged by a record during displacement of the latter, and the action of the detector upon the control mechanism is dependent on the extent of movement of the arms 9 which must occur before the record is released, and is therefore dependent on the size of the record. A modified form of record supporting and delivery mechanism is described, Figs. 6, 7 (not shown), in which, instead of the bent post 4, an upright supporting post is provided, rotating with the turntable and having at its extremity a short ball-headed spindle seated on a thrust bearing, the records resting on the ball. The edge of the pile of records is supported on shoulders carried by a pair of vertical posts; the device for frictionally gripping the edges of the records which lie above the bottom one in the pile consists of a series of plates mounted together with spacing washers on a vertically movable spindle, the bottom plate being fixed and the others loose, . a spring being interposed between the top plate and a knob at the upper end of the spindle. For displacing the records, there is provided a pair of laterally movable grooved studs which engage the lowest record at points between the stationary supporting shoulders and the frictional gripping device, each stud being mounted on a platform movable by a parallel-motion linkwork. Specifications 399,172 and 459,208 also are referred to.