GB190826756A - Improvements in or relating to Sound Recording and Reproducing Apparatus. - Google Patents

Abstract

26,756. Turner, W. J., and Watts, G. Dec. 10. Gramophones.-The turntable is rotated at a constantly varying speed from a constant-speed motor by means of a driving-cone and friction wheel in order to produce a constant linear velocity under the stylus. The driving-cone 8 is rotated through gears 4, 3 from the motor spindle 1. The turntable spindle 35 is driven by gears 34, 33 from the cone 8 by a friction-wheel 9 which is traversed along a keyed spindle 12. A saddle 14, carrying the stylus holder 16, is traversed on its frame 22 by means of a feed-nut on the screwed shaft 24, which shaft is rotated from the shaft 12 through gears 28, 29, a shaft 30, and gears 31, 32. The saddle 14 is provided with vertical and horizontal adjustments. The cone 8 can be moved radially about a centre 7 against the action of a spring 38 which normally holds it against the friction wheel. An arm 25 on the saddle 14 has a bifurcated end 25<a> loosely engaging a pulley 9<b> attached to the friction-wheel 9, and thus feeds this wheel along the cone 8, as the saddle 14 traverses the stylus across the record. When the stylus is being set by rotating a handle on the screw shaft 24, a nut 27 may be slacked to loosen the gear-wheel 32 and thus avoid its rotation. In a modification, the turntable-operating shaft 12 is hollow and contains a feed-screw which is clutched through a slot by a movable half-nut.