Patent GB-113668-A (GB)
Title: Improvements in and relating to Stop Mechanism for Talking and other Machines.
IPC: G11B17/02
Filed: 1917-03-03
Abstract: 113,668. Marks, E. C. R., (American Graphophone Co). March 3, 1917. Periodic.-Talking machines are automatically arrested at the end of a reproduction by means of a travelling tripping-gear, one element of this gear being traversed by the driving-mechanism of the machine and the other by the tone-arm; and the stop mechanism is released and the tripping- gear re-set by returning the tone arm to starting position. The stop mechanism comprises a rotating disk driven by the record support and an element frictionally driven thereby, and arrested on the release of the tripping gear. Fig. 1 is a plan of the machine, Fig. 4 a plan of the mechanism with the parts 40, 41 removed, and Fig. 6 an elevation showing the stop in action. A rubber-rimmed disk 18 carried on a vertical pin 14 is normally pressed by a spring into driving-engagement with the turntable 2, and has a frictional connexion to an arm 20, the arrest of the turntable being effected gradually when a stop 39 is placed in the path of this arm. The pin 14 is mounted in a frame 10, 11, 12 pivoted on a pin 9, and carries a worm rigidly coupled to the arm 20 and gearing into a worm wheel 24 on a horizontal threaded shaft 25. A part-nut 28 engaging the screw 25 is carried on a lever 27 pivoted on, and sliding along, a rod 26. A pin 46 provided with a shoulder 46' projects upwardly from the lever 27 and forms one member of the tripping- gear, the other member comprising a hinged extension 41 of an arm 40 pivoted on the pin 9. During the playing of a record, the pin 46 moves proportionally to the speed of the turntable, while the co-operating slot 45 in the extension 41 of the arm 40 is advanced proportionally to the feed movement of the tone arm which carries a rod 51 engaging a forked projection 50 on a disk frictionally coupled to the arm 40. On the completion of the record, the feed movement ceases and the turntable movement continues, so that the arm 41 falls over the pin 46 and a lug 43 depresses the stop 36 and arrests the turntable, the stop 39 being carried on a tilting frame 34 pivoted on the pin 26 and balanced so that normally the stop is raised. At the same time, the outer end of the extension 41 strikes the end of the lever 27 and disengaged the part-nut 28. In order to restart the machine, the tone-arm is moved outwardly, causing the arm 40, 41 and the lever 27 to be returned to initial position. A further movement of the tone-arm causes a pin 54 to engage the fork 55 of a lever 56 pivoted on a pin 57 to the frame 10. The opposite arm 62 of this lever is thus moved into engagement with a bevel surface 38 formed on an extension of the tilting frame 34, the stop 39 being thereby withdrawn and the arm 41 raised by means of the lug 43. The part-nut 28 is then free to fall into engagement with the screw 25. A slight further movement of the tone arm brings a lug 58 on the lever 56 into engagement with a fixed stop 59, which acts as a fulcrum and causes the frame 10. 11, 12 and the disk 18 to be moved away from the turntable which then starts to rotate. The needle having been placed on the initial record groove, the tone-arm begins to move inwardly and the frame 10 and lever 56 gradually return to normal position under the influence of a spring 60; also the arm 40 and its extension 41 are moved to place the edge of the slot 45 over the shoulder 46<1>. The disk 18, having re-engaged the turntable rim, is driven thereby, and the pin 46 and the co-acting member 41 are moved jointly, until tripped at the end of the record.