Patent GB-738449-A (GB)
Title: Talking machine
IPC: G11B17/02
Filed: 1953-09-01
Abstract: 738,449. Automatic gramophones. THORENS SOC. ANON. Sept. 1, 1953 (Oct. 13, 1952], No. 24120/53. Class 40 (2). A gramophone for automatically playing single records placed thereon is provided with manual control members connected to the motor switch and to movable stops defining the starting position of the pick-up arm for three standard sizes of records. The automatic movements of the pick-up arm Pare controlled in a well known manner by a camdisc 8 mounted on the same shaft as a toothed wheel 6 driven by the turntable shaft 5 through a movable intermediate wheel 38. This wheel is brought into the operative position following the functioning of a tap-tap lever 46 which during its rapid inward movement carries a hook 48 beyond a lug 49 on a spring-loaded b.ell-crank 44 so that on the return movement of the hook 48 the said bell-crank 44 is moved counterclockwise out of the path of a pin 42 on a plate 39 carrying the intermediate wheel 38. The automatic cycle thus commenced proceeds until the pick-up arm is swung to its outermost position, upon which a pin 50 on wheel 6 engages a pin 51 on a latch lever 52 and releases the switch arm 55. After the placement of a fresh record on the turntable, the motor is restarted by the operation of one of the push buttons 68, 69 or 70, Fig. 6, which moves a bell-crank 80 and relatches switch arm 55 through the medium of arm 83 and rod 86. At the same time, a further arm 87 is set to a position which causes a stop member 26 to be set, via a link 92, corresponding to the size of record to be played. The pick-up arm is swung horizontally by means of a pin 18 engaging a window 19 in the end of an arm 20 hinged on a fixed axis 11 on which the cam follower arm 10 also pivots. Arms 10 and 20 are coupled by a spring 21 which normally maintains them in the relationship shown in Fig. 2. Arm 20 carries a further arm 30 hinged at 36 and having an edge 31 to engage pin 18, and an abutment 32. Arms 20 and 30 are coupled by a spring 34 to maintain them in the position shown in Fig. 2. Lever 20 also has an abutment 37. When button 68, Fig. 6, is pressed, the appropriate bell-crank 80 passes beneath a raised part 88 of the arm 87, and the stop member 26 remains in the position shown, so that during inward movement of the pick-up arm by the edge 31 the abutment 37 is advanced until it encounters the surface 28 of the member 26. Such position corresponds to the setting down position for a smallest size record. When the button 69 is pressed, the appropriate bell-crank 80 moves the member 26 so that surface 28 intercepts abutment 32, whereby arm 30 is held back and edge 25 of window 19 moves the pin 18 to a position corresponding to a medium size record. When button 70 is pressed, surface 29 intercepts both abutment 32 and 37, and arm 30 is held back to a position corresponding to a large size record. When each press-button is operated it is held inthe down position by the arm 83 which engages the appropriate shoulder 94. The remaining buttons cannot be operated, because the arm 83 engages slots 95. A record may be rejected during playing by merely pressing again the button already in the operative position. Such action moves a lever 100 a small amount to trip the bell-crank 44 and engage the intermediate wheel 38 to start another automatic cycle. Specifications 607,600 and 638,749 are referred to.