GB414091A - Improvements in and relating to means for driving the turntables of talking machines - Google Patents

Abstract

414,091. Variable speed epicyclic gearing. ELECTRIC & MUSICAL INDUSTRIES, Ltd., Blyth Road, Hayes, Middlesex. Jan. 27, 1933, No. 2698. Convention date, Feb. 27, 1932. [A Specification was laid open to inspection under Sect. 91 of the Acts, July 28, 1933.] [Class 80 (ii).] Relates to speed-change gearing for gramophone turntables, of the kind described in Specification 414,090, and consists in providing in combination with a constant-speed spindle, having the turntable mounted thereon, mechanism to enable the spindle to rotate the turntable at different desired speeds, and means carried by the turntable and operable for controlling the speed-change mechanism. The controlling member, in the construction shown, consists of a slide 39 mounted on the turntable and having a finger-piece 40 projecting through a slot 38. The slide has a slotted inclined end 43, adapted to engage a member 45 which is pivotally attached to the outer ball-race 22 of speed-reduction gearing, which gearing is similar in construction to that shown in Fig. 9 of Specification 414,090. The member 45 has a resilient detent 30 attached thereto, the pronged end 35 of which is adapted to dig into the surface of the motor-board 1. With the parts in the positions shown, the outer raceway 22 is restrained by the detent 30 against rotation, and the turntable is driven at a low speed relatively to the spindle 3 through the rolling action of the balls 23. In order that the turntable may be driven at the same speed as the spindle 3, the slide 39 is pushed inwards, so that the raceway 22 is locked to the turntable by engagement of the parts 45, 43. In a modification, the pivoted member 45 is replaced by a spring - controlled vertically - slidable restraining member, adapted to be engaged at its upper end by a slide on the turntable, and having teeth at its lower end for engaging, when required, with the motor-board.