Patent GB-155641-A (GB)
Title: Improvements in sound reproducing machines
IPC: G11B17/16
Filed: 1919-09-22
Abstract: 155,641. Kenny, W. R. Sept. 22, 1919. Multiple machines; driving; stopping; feed motions: returning sound-box to starting point; turntables; raising and lowering sound-boxes.- In an electrically-driven gramophone, records played in succession by the same reproducer are fed from above on to a turntable, which is lowered step by step to receive each record. The records arrive in position with an initial spin. Means are provided for automatically resetting the reproducer by carrying it through a complete circle, for raising and lowering the sound-box automatically without shock, for stopping the driving-motor and manually resetting the turntable when the record-magazine is empty, for replaying any desired record, and for omitting part of any record. Feed of tone arm. The tone arm 41, Fig. 1, rotates through a complete circle for every record played. During performance, the reproducer is moved by the record groove through a small arc of a circle. At the end of the record, a central clamp 36, Fig. 10, of conducting-material makes contact with a member 85 on the tone arm, and closes a circuit through the electro-magnet 96 and motor 49, by way of a brush 72 and a slip-ring 62 carried by the tone arm. The electro-magnet 96, when energized, raises the needle from the record, and the motor 49 carries on the rotation of the tone-aim through the remaining major arc of a circle. When the contact at 36, 85, is broken, the circuit of the magnet 96 and motor 49 is still maintained closed by a conducting-segment on the slip-ring 61 carried by the tone-arm, the slip-ring being connected to the conductor 75 and making contact with a brush 71. The brush 71 eventually reaches a non-conducting segment on the slip.ring, this segment corresponding approximately with the playing part of the tonearm's movement. The circuit of the magnet 96 and motor 49 is still kept closed for a short time, however, by contact of the wiper 85 on the tone arm with a conducting-clamn 34 on the periphery of the record. When this contact is broken, the magnet 96 is de-energized and the lever 97, Fig. 3, rises and lowers the reproducer which is integral with it, the motion being checked by a dash-pot 101. At the same time the motor 49 stops and the tone-arm, which is connected to the motor by a free-wheel clutch, is carried on by the needle engaging in the record groove. The central and peripheral conducting clamps 36 and 34 may be wide enough to cut out parts of a record. Any part may also be cut out by closing the switch 87, which completes the circuit of the feed-motor 49 and reproducer-controlling magnet 96 through the brush 70 and slip-ring 61. Drive of turntable. The turntable 12 is integral with a sleeve 13 which is capable of vertical motion and is keyed by pin-and-slot to the shaft 14. The sleeve has a floating pinion 50 which is constantly in gear with the shaft of the driving motor 55. The latter can be stopped by opening a hand-operated switch, and it is automatically stopped by the switch 91, 92, Fig. 1, when the turntable reaches its lowest position at the emptying of the record-magazine. The pinion 50 also drives a speed-governor through gearing 56. Record-changing device. The records are stored above the turntable on a screw-threaded magazine-spindle 39. They are held by peripheral clips 29 which are successively tripped by the Z-shaped rod 28. The records reach the turntable'with an initial spin due to the screw-thread 38. The rod 28 is raised one step by the pinion 25 whenever this is rotated by the rack 19. The rack 19, turntable 12, and part 91 of the stopping- switch fall one step whenever the escapement 20 is actuated by the rod 22, which is depressed at the proper moment by a hinged member 24 on its engagement with a roller 102 carried by the tone-arm. At the end of a performance the turntable can be raised manually by pulling out and rotating a shaft 110 which then gears with a rack on the sleeve 17. To replay any record, the member 24 is turned back out of engagement with the rod 22.