Patent GB-593047-A (GB)
Title: Improvements in automatic record changing mechanisms for gramophones
IPC: G11B17/02
Filed: 1945-04-28
Abstract: 593,047. Pause mechanism for record-changing devices. AKTIEBOLAGET GYLLING & CO. April 28, 1945, No. 10770. Convention date, Oct. 28, 1943. [Class 40 (iij] A record-changing device for a phonograph has a pro-set pause mechanism for automatically extending the time period between successive records, comprising a speedreduction gear operating between the motor and a cycling cam of the normal type in which one complete revolution is made during a record-changing cycle. A shaft 7, fitted with a knob 8, is mounted to rotate in a fixed sleeve 6 on a mounting plate 1. Rings 9 and 11, and a spring washer 10, are provided to enable any setting of the shaft 7 to be retained by friction. The lower end of the shaft 7 has a housing 27 fixed to it containing a flat-section spiral spring 28, the outer end of which is connected to the housing 27 and the inner end to a ring 23, which, although not fixed to the shaft 7, is restricted in its rotation by an initial set in the spring 28 which thereby retains pins 25 and 26 in contact. The ring 23 is connected by a coupling 19, Fig. 4, to a ring 17 which has a large amount of side play on the shaft 7 and has a toothed inner circumference 18 and a notch 22, Fig. 3. Within the recess 18, mounted freely on the sleeve 6, and having an outer toothed surface 16, Fig. 3, is a ring 52 which is coupled by a spring-clutch 14 to the lever 12 in such a manner that a drive is effected, by the lever 12, in a counterclockwise direction only. The lever 12 is held by a spring 55, Fig. 1, against an eccentric disc 13<1> mounted on a shaft 3 driven by the motor. A sliding bar 29, mounted for engagement with the notch 22, is fitted with a roller 32 which engages an arcuate spring 33 on the cycling disc 2 at an appropriate moment during the cycle. At the free end of the spring 33 is an element 34 which is movable radially in a recess in the periphery of the cycling disc 2. During a cycle when no pause is required, the end of the bar 29 rests in the notch 22, so that no engagement is effected between the toothed surfaces 16 and 18, and the arcuate spring 33 is thereby permitted to remain pressed against a stop 54 throughout the cycle so that the element 34 preserves the continuity of the periphery of the disc 2 and thus maintains an uninterrupted drive by a friction-roller 4 on the shaft 3. When a pause between records is required, the knob 8 is rotated to a suitable indication on the mounting plate 1, Fig. 1, so that the shaft 7 rotates'the ring 17, via coupling 19, to a position in which the bar 29 cannot enter the notch 22, but is held back to a position in which the roller 32 subsequently engages the spring 33 and sets the element 34 away from the periphery of the cycling disc 2 sufficiently to interrupt the direct drive between the shaft 3 and the cycling disc 2. At the same time, pressure of the bar 29 displaces the ring 17 so that the toothed surfaces 16 and 18 are brought into engagement. When the sector of the cycling disc 2 containing the. element 34 reaches the friction-roller 4, direct drive is interrupted until the lever 12, oscillated by the eccentric 13<1>, has rotated the ring 17 counterclockwise, via the spring-clutch 14, sufficiently for the bar 29 to re-engage the notch 22. At this moment engagement between the toothed surfaces 16 and 18 is broken and direct drive is restored. When the arcuate spring 33 has moved clear of the roller 32 following the rotation of the cycling disc 2, the ring 17 is restored to its original setting, determined by the co-operating pins 25 and 26, owing to the action of the coiled spring 28 which has become tensioned by the step-by-step movement caused by the lever 12 and spring-clutch 14. Provision is made to effect operation of the pause mechanism between alternate records only, by means. of a movable post 30, a cog 44 and a cam 45, and a lug 36 on the cycling disc 2, the function of these components being to effect an alternative raising and lowering of the arm 29 for corresponding disengagement and re-engagement of the roller 32 with the arcuate spring 33.