GB200510A - Improvements in the driving mechanism of disc sound recording and reproducing apparatus - Google Patents

Abstract

200,510. Ingram, W. H., Ingram, J., and Atkinson, E. J. R. July 4, 1922, [Convention date]. Void [Published under Sect. 91 of the Act]. Speed, regulating. - In sound-recording and reproducing machines of the kind in which a constant linear speed of the record under the stylus is produced, the position of the brake member associated with the governor is automatically varied by means actuated by the rotary movement of the tone-arm. The tone-arm, in the construction shown, is mounted in a rotatable socket 6b, to which is secured, by resilient arms (not shown), a sector-shaped plate 9. The underside 10 of the plate is inclined as shown, and against it is adapted to bear a pad 13 on a rod 12, the opposite end of which carries the brake-pad 11 with which the governor disc 14 contacts. A spring 18 may be provided to tend to raise the rod 12. The vertical position of the brake-pad 11 is varied bv the incline 10 as the tone-arm travels, thus causing the angular speed of the turntable to be increased progressively during the inward movement of the stylus. In order that the machine may be used with ordinary records, run at a constant angular velocity, the rod 12 is adapted to be moved laterally by means of a fork 20 projecting from a rotatable rod 21, so that the pad 11 may be clear of the disc 14. An arm 28 on the rod 21 carries a second brake-pad 27 which moves into operative position over the governor disc 14 when the pad 11 is shifted aside, to enable the speed to be regulated by hand in the usual way. This regulation is affected by adjusting the disc 14 vertically through the action of a cam-plate 29 on the governor spindle 17<a>. By turning a knob 33 on a spindle 31 which carries the cam-plate, the governor can be raised bodily, thus varying the normal position of the disc 14 relatively to the pad 27. The sector plate 9 may bear against rollers 38 mounted on the framework. The plate 9 may be so disposed as to move in a plane at any angle to the plane of movement of the tone-arm. If the plate is arranged vertically, the rod 12 may be controlled through a bell-crank lever or the like, or the governor spindle may be arranged horizontally. Instead of the plate 9 with an inclined plane surface, a cam with a curved surface eccentric to the tone-arm axis may be used.