GB343350A - Improvements in and relating to gramophones - Google Patents

Abstract

343,350. Brakes applied by special responsive means. ROBERTS, J. H. T., Dashwood House, Old Broad Street, London. March 17, 1930, No. 8597. [Class 103 (i).] A governor adapted to maintain a .substantially constant angular velocity of a gramophone record is fitted with a wheel 2 which is arranged to engage the edge of the turntable or record or the upper surface of the record, and the mounting of the governor is such that it is adapted to be shifted into or out of operative position in engagement with the turntable or record. The wheel 2, Figs. 1 and 2, has a rubber tyre 3 engaging the edge of the turntable 1 and is adapted to drive the governor spindle through gearing 12, 13. The governor mechanism is contained within a case 4 which is adapted to be moved about a screw or rivet 5, and a spring 7 mounted on a pillar 8 is adapted to engage the case and hold the wheel 2 in contact with the turntable 1. The governor may be held out of the operative position by a clip. Instead of the gear wheel 12, 13, a disc mounted on the governor spindle may engage frictionally with the wheel 2. Alternatively, the wheel 2 may be mounted on the governor spindle and engage with the upper surface of the record, the device being pivoted so as to be movable both vertically and horizontally. In a further modification, the governor may be of centrifugal type comprising weights 19, Fig. 4, on spring arms 25 carried by a rotary member 18 driven either by gearing or otherwise from a friction wheel in contact with the record or turntable, and co-operating with a collar 20 adjustable in diameter by a screw 21 and block 23. The governor device described is intended to be used in addition to the usual governor employed with the gramophone and to be operative when a record is to be driven at a substantially different speed, say 30 revolutions per minute, from that of normal working.