Patent GB-643148-A (GB)
Title: Automatic phonograph
Filed: 1947-01-10
Abstract: 643,148. Magazine gramophones. DEHN, S. G. (Wurlitzer Co., R.). Jan. 10, 1947, No. 909. [Class 40 (ii)] In a magazine gramophone of the type in which a group of record carriers are selectively movable for placement of a record on the turntable, the carriers are mounted on a vertical post 41, Fig. 4, so that the selected carrier may be swung horizontally into position over the turntable by means of a finger whose vertical position is controlled by a cam having opposed duplicate surfaces whereby one surface effects engagement of the finger with alternate carriers, and the other surface the intermediate carriers. Individual carriers are selected by the finger 48, Fig. 7, which engages one of the notches 51 in the hubs of the record carriers and is movable up and down a swinging yoke 46 under the control of a rod 49, sliding collar 54 and lever 55. The lever 55, which is pivoted on the frame at its other end, has a cam-follower intermediate its length which engages an approximately heartshaped groove 81, Fig. 5, in a cam 80 on a shaft 56 which is rotated at each automatic cycle by a segmental gear 58, under the influence of a cam 35 on a cycling shaft 33, to a position determined by an arm 85 which engages one of the rods 87, Fig. 11, on a selector dial 90, Fig. 4. A spring-box 71 enables lost-motion to be effected between the shaft 56 and the pinion 57 when the arm 85 is intercepted by one of the rods 87 and rotation of the shaft 56 is arrested. The selected carrier is swung to a position over the turntable 19 by a rod 52 actuated by cam 36. The turntable 19 is then elevated through the central aperture of the carrier to lift the record and bring it into contact with the stylus of a pick-up 22, which is supported and held back in its outermost position by a spring-loaded pin 137, Fig. 2. The turntable 19 is elevated by means of a spring 160, Fig. 5, acting on parallel link connections 159 under the control of a cam-follower arm 165 which is linked to the upper link connection 159 and is moved by the cam 34 on the cycling cam-shaft 33, the cam-follower arm 165 being held in contact with the cam 34 by a spring 164. Movement of the cycling cam-shaft 33 is initiated at the end of a record by the eccentric terminal groove which causes a pawl 148, Fig. 5, on an arm 145 on the tonearm shaft 146 to engage a notched rod 149 on a latch 150 which releases a spring-loaded lever 152 on a shaft 154 carrying a clutch-release lever 158. The clutch 174 effects engagement between the cam-shaft 33 and a toothed wheel 32 driven by a worm-wheel 31 on a shaft 25 coupled to the motor 24. A further wormwheel 26 on the said shaft 25 drives the turntable shaft 30. The tone-arm 20 is swung outwardly, at the end of a record, to its initial position by means of a link 180, Fig. 4, attached to the yoke 46. The rods 87 of the selector dial 90 are released by means of armatures 92 operated by solenoids 93, the circuits through which are completed by push-button switches on a selection panel on the front of the case 10, Fig. 1 (not shown). As each automatic cycle is completed, the particular rod 87 engaging the arm 85 is restored to its latched position by the longitudinal movement of shaft 56 under the control of a lever 106 and cam 108. The arm 85 then becomes free to hunt round the selector dial 90 to the next protruding rod 87. When the last rod 87 is returned to the latched position, the plate 97 and plunger 99 are released under the tension of spring 100 to open a switch 105 controlling the motor 24. The motor is started by the closing of switch 105 following the operation of any one of the press switches controlling current to one of the solenoids 93.