Patent GB-665834-A (GB)
Title: Improvements in or relating to gramophones
IPC: G11B17/02
Filed: 1948-04-12
Abstract: 665,834. Automatic gramophones. MILTON, A. J. April 12, 1948 No. 10118/48. Class 40 (ii). In an automatic gramophone of the kind described in Specification 656,826, [Group XXIV], the cycling cam-disc 9, Fig. 1, has a pair of bevelled driven surfaces 7 and 8 engaged by similarly bevelled surfaces of constantly rotating driving members 4 and 5, respectively, the upper surface 7 having a notch 18 to interrupt engagement with the member 4 at the end of an automatic cycle, and the lower member 5 being controlled by a spring member 14 for completing or interrupting engagement with the lower surface 8 by means of an appropriate cam-surface on cam-disc 9, or by means operated by movements of the pick-up arm. During the playing of a record the member 4 idles in the notch 18 in the surface 7 of the cam-disc, and member 5 is held out of engagement with the surface 8 by means of a pin 19 on the spring member 14, and an intercepting arm 28 swinging on a spindle 24, Fig. 8. At the end of the playing of the record, a spring member 20 on the end of a lever 21 rigid with the pick-up arm shaft engages the teeth 22 on a quadrant 23 mounted securely on the spindle 24, so that the arm 28 is moved away from the pin 19 on the spring member 14, and the member 5 is permitted to engage the surface 8 of the cam-disc 9 to start a new automatic cycle. As soon as the cam-disc 9 has been set in motion the drive is maintained, and the automatic cycle completed, by means of the engagement of the member 4 with the surface 7. During a later period in the automatic cycle, when the pick-up arm has been swung outwardly, a cam 26, Fig. 6 (not shown) on the cam-disc 9 presses the end 15 of the spring member 14 downwardly, so that the member 5 is disengaged from the surface 8 and the arm 28 is moved once more into engagement with the pin 19 under the influence of a spring 40 on an arm 25 mounted on the spindle 24. An automatic cycle may also be initiated during the playing of a record by means of a knob above the platform controlling a spring-loaded trip rod 41 which moves the lever 25 to release the pin 19 and effect re-engagement between the member 5 and the surface 8. Means are provided for switching off the driving motor, after the last record from the magazine has been played, operated by a feeler member 67, Figs. 3 and 4, which is mounted on a sliding pillar 68 and rests on the upper record of the stack in the position shown in full lines in Figs. 3 and 4. The pillar 68 controls a lever 45 which may be tilted about a pivot 69 from the full line position shown in Fig; 4 to the chain dotted position. The lever 45 carries a lever 48 which is pivoted at a point 50 and is held back against. the tension of a spring 70, Fig. 8, during the playing of records, by a spring-loaded latch 51 pivoted at 71. When the last record drops, the pillar 68 and lever 45 move to the chain dotted positions. At the end of the playing of the record when the pick-up arm has been swung outwardly beyond the edge of the record, the cam plate 62, Fig. 8, attached to the pick-up arm shaft, strikes a bellcrank lever 60 which moves a spring-loaded plunger 54 longitudinally to strike the arm 64 to release the latch 51 and lever 48. The lever 48 carries a pin 49, Fig. 4, which operates the tumbler 47 of a switch 46 whereby the motor circuit is broken. When the arm 67 is returned to the position shown in Fig. 3, the pillar 68 is lifted again by means of a pin 76 and an arcuate slot 77 11 in a member 78, and is retained in that position by a spring-loaded catch 80 so that the pin 76 can only move horizontally along the ledge 79. When the arm 67 is swung inwardly again over the stack of records an arm 75 on the pillar 68 engages a knob 73 on the end of lever 48 to move it to the operative position where it is held, until released, by the latch 51. The turntable 1 is carried on a shaft 2 which rotates in a bearing in the platform 3. The members 45 are free to slide up and down the shaft 2 in splines 6. Specification 656,455 also is referred to.