GB300093A - Improvements in sound reproducing machines - Google Patents

Abstract

300,093. Hosoi, I. May 2, 1928. Driving.-A gramophone turntable 1 is driven at a gradually increasing speed to effect. constant tracking speed of the stylus by a friction wheel 2 which is splined on and traversed along a spindle 4 driven by pinions 7, 8 from a governorcontrolled spring motor, the. spindle 4 which extends radially of the turntable being mounted in a frame 5 mounted on horizontal pivots 10 in alignment through the contacting pitch surfaces of the pinions 7, 8 and pressed upwardly at its outer end by a spring 13. The friction wheel 2 is traversed along the spindle 4 by a, member 15 guided along a fixed rod 20 and a screw 21 driven from the turntable spindle 29 and carrying a fork 17 engaging the wheel boss 3 and a nut member 16 normally raised by a spring into engagement with the screw 21. The wheel 2 can be moved out of driving engagement, with the turntable by depressing a button 30 acting on the outer end of the pivoted frame 5, the nutmember 16 being thereby depressed out of engagement with the screw 21. Adjustment of the nut-carrying member 15 and of the wheel 2 can then ba effected by turning a knob 39 geared with a pivoted segment 35 engaging the guide sleeve 18 of the member 15. If adjustment is made so that the nut member 16 is brought over a non-threaded part. at the inner end of the screw 21, the machine can be used for playing the usual records. The knob 39 may carry a pointer moving over a graduated dial 41, and the tone-arm may carry a pointer moving over a graduated dial around its mounting. These dials may be calibrated so' that similar readings correspond to adjustment of the friction wheel immediatelv below the stylus.