Patent GB-620614-A (GB)
Title: Improvements in or relating to automatic gramophones
IPC: G11B3/08
Filed: 1946-12-19
Abstract: 620,614. Gramophones. NAAMLOOZE VENNOOTSCHAP PHILIPS' CLOEILAMPENFABRIEKEN. Dec. 19, 1946, No. 37397. Convention date, Sept. 10, 1943. [Class 40 (ii)] In an automatic gramophone in which records are inserted edgeways through a vertical slit 2, a single control knob 5 effects, by a series of movements, centring and seating of a record 1 on a vertically-mounted turntable 9, and, by means of a rod 6 passing through the centre of the record 1 from the said control knob 5, controls the switching-on mechanism and the movements of the pick-up arm 32 enabling the stylus to be set down at the start of the record. When a ten-inch diameter record is inserted, it rests on a roller 3 on a spring-loaded lever 47, Fig. 2, and against a stop 41 on a member 50. Inward movement of the knob 5 brings a spring- loaded conical member 7 on ball-bearings 8 into contact with the central aperture 1a of the record 1 and serves to centre and hold it in contact with the turntable 9. At the same time a surrounding member 12 engages a bell-crank lever 13 which engages a strip 14 coupled to the lever 47 and moves it downwards so that the roller 3 disengages the edge of the record 1. The position of the stop 4 is such that the centring of the record 1 effects disengagement between the stop 4 and the record 1. The inner end of the rod 6 has a squared end 15 which passes through the centre of the record 1 and fits into a squared recess 16 in the end of a rod 17 so that when the knob 5 is rotated the rod 17, and the arm 22 and cams 19, 20, 21 thereon, are also rotated against the tension of a spring 42. A detent member 43 is provided which engages the cam 21 and prevents the shaft 17 returning to its initial position until the record has been played, while a bayonet-catch is provided on the knob 5 to prevent disengagement of the rods 6 and 17 owing to pressure of the spring 44. During the first part of the rotation of knob 5 the motor is thrown into gear by the arm 22. Upon further rotation of the knob 5, the stop 33 is withdrawn, so that the pick-up arm 32 is free to move towards the centre of the record. A small torsion spring 36 is provided to hold the pick-up arm 32 against a stop 34 until the stylus enters the start of the groove of the record 1. Further rotation of the knob 5 permits the pick-up arm 32 to be lowered on to the record, under the influence of a leaf-spring 4, by means of cam 20, arm 37, rod 38, arm 39 and rod 40. At the end of the playing of the record the detent member 43 is released, by means not shown, so that the mechanism is returned to the position shown in the Figures. A pushbutton may also be provided in order to release the detent member 43 at any time before the end of the record. In the event of a twelveinch diameter record being inserted, the edge of the record comes into contact with a stop 45 so that the lower part of the record moves the roller 3 to the position 3a. The resulting movement of the lever 47 causes the link 49 to move upwardly and rotate the member 50, carrying downwardly-directed stop 4 and upwardlydirected stops 34, 35, 90 degrees clockwise about a stop-member 51. The position of the record thus becomes limited by the stop 51 and the pick-up arm 32 comes to bear against stopmember 35 in the position 35a, after which all the operations are performed as previously described with reference to a ten-inch diameter record.