Patent GB-667768-A (GB)
Title: Improvements in automatic gramophone record playing apparatus
Inventor: BOYLE SYDNEY JAMES
IPC: G11B17/02
Filed: 1948-10-07
Abstract: 667,768. Automatic gramophone. apparatus. ELECTRIC & MUSICAL INDUSTRIES, Ltd. Oct. 6, 1949. [Oct. 7, 1948] No. 26109/48. Class 40 (ii). Automatic gramophone record playing apparatus in which records are fed singly to the turntable from a pile, and the pick-up is lifted and swung out after each record, comprises driving means to move a member 35 in one direction to effect a predetermined inswing of the pick-up, and means for moving the member in a transverse direction during the automatic cycle whereby it is not engaged by the first driving means, so that it is not moved inwardly. Figs. 1 and 4 show vertical sections of the apparatus and Fig. 2 shows an under plan view. The record pile is supported on a shoulder of a central spindle 4, and on a side support, either 7 or 8 according to the size of the record, as described in Specification 617,864. A control disc 20 is provided, which rotates once at the end of each record playing to control the automatic cycle. The disc is provided with a recess but is otherwise in frictional engagement with a hollow shaft 15 which encloses spindle 3, so that after an initial movement, the disc is rotated for one revolution. At the end of a record playing, the inner position of pick-up 17 mounted on shaft 18 causes lever 26 to engage projection 47 to start disc 20 which is then rotated for one revolution by shaft 15. Alternatively, if the record is provided with an eccentric groove, the oscillations of pick-up 17 are transmitted to a pawl 72 by means of levers 69 and 70, which engages the surface of disc 20 to initiate the rotation. During the rotation of disc 20 the following operations occur : (i) Cam 21<SP>1</SP> rotates lever 23 about pivot 24 to operate pushrod 25 which raises the pick-up from the record. (ii) Pin 32 on disc 20 engages lever 29 which is pivoted at 30, which via levers 27 and 26, moves the pick-up outwardly. (iii) Lever 33, which is pivoted on pin 32, rotates spindle 3 via lever 34, to release the lowermost record on to the turntable. (iv) Pin 44 on the upper surface of disc 20 engages arm 57 so that it slides longitudinally. This has no effect except when, as described below, the last record has been played. (v) Pin 44 engages lever 35, which rotates about pivot 38 and engages pin 45 on lever 27, to move the pick-up in to the starting position. (vi) Cam 21<SP>1</SP> allows lever 23 to release push rod 25 so that the pick-up is lowered on to the record. (vii) A lug on lever 73, Fig. 9 (not shown), mounted on the top of disc 20 engages lever 35 against the action of a light spring, so that the pick-up is gently moved into the first record groove. When the last record is released, an arm 12, which rests on top of the record pile, drops and tends to depress a rod 61, Fig. 5 (not shown), against the action of a spring (not shown). The end of rod 61 passes through a slot in arm 57 having a narrow portion, so that rod 61 may descend only when arm 57 has been displaced by the action of pin 44. When disc 20 rotates after the playing of the last record, rod 61 thus descends and engages end 43 of lever 35, which is also pivoted about a horizontal axis 36, so that the other end of lever 35 is moved clear of pin 44 and the pick-up is not moved inwards but is lowered on to a rest 63, Fig. 3 (not shown), so that it depresses a rod 64. The lower end of rod 64 then engages a resilient switch arm 66, to break the motor circuit. The apparatus is adjusted for dealing with 10 inch or 12 inch records as follows. Support 8 is pivoted and is placed in the lower or horizontal position to support a pile consisting entirely of 10 inch records, but may be raised to a vertical position to allow a pile of 12 inch records to be supported on support 7. The vertical pivot 38 of lever 35, which controls the inward movement of the pick-up, is mounted on an arm 39 which is pivoted at 39<SP>1</SP> to a fixed support plate 31. Support 8 is coupled to a rod 50, Figs. 5-8 (not shown), so that when the support is raised, rod 50 is depressed which rotates a lever 51 having a lug 53, Fig. 8 (not shown), which rotates arm 39 so that the pivot 38 is moved to the right of slot 40 in Fig. 2. When lever 35 is then rotated by pin 44 during the rotation of disc 20, the displacement of its pivot 38 causes a reduced movement to be given to lever 27 so that the pick-up is moved in only the amount necessary for a 12 inch record. Instead of adjusting the position of pivot 38, a modification allows for the disc 20 to be provided with two pins, the second being nearer the centre and higher than the first, so that the outer pin controls the movement for a 10 inch record, and for a 12 inch record additional means are provided to adjust the position of lever 35 in the vertical plane so that it is clear of the outer pin but is swung through a smaller angle by the inner pin. Alternatively, one edge of lever 35 may be provided with a projecting lug, so that a single pin on disc 20 may be caused to engage either edge of lever 35 by rocking lever 35 in the vertical plane, thereby to provide the required two inward movements. In all cases, the adjustment of lever 35 may be effected by movement of support 8, or if a mixed pile of records is used, by a feeler or other device operated by the record fed to the turntable. The apparatus may be started by means of a knob 76, Fig. 3 (not shown), which rotates lever 77, which in conjunction with levers 78 and 80, and pawl 81, rotates disc 20 and raises the pick-up rest rod 64 to switch on the motor. Operation of knob 76 during the playing of a record initiates the automatic cycle to play the next record. Single records may be played by placing the pick-up manually, whereby the motor is switched on, and the pick-up returned to the rest automatically. A dog clutch is provided in shaft 18 to prevent damage if the pick-up is moved beyond its normal angular range. Specification 617,864: is referred to.