Patent GB-254715-A (GB)
Title: Improvements in and relating to talking machines
IPC: G11B3/08
Filed: 1926-06-28
Abstract: 254,715. Compagnie GÚnÚrale des Machines Parlantes PathÚ FrÞres. July 3, 1925, [Convention date]. Void [Published under Sect. 91 of the Acts]. Feed mechanism; turntables; sound-boxes, raising, positioning, and lowering; tone-arm joints; records.-In a sound-recording and reproducing machine of the disc type, adapted especially for dictation purposes and the like, the sound-arm for recording is provided with a stud or point coacting with a spiral guiding groove on the lower face of the record carrying turntable, or of the record disc itself. The machine shown, which is of the portable type, comprises separate sound-arms 5, 6, provided with recording and reproducing sound-boxes 26, 51 respectively. Both sound-arms are pivoted on a plate 3, below which are the motor 8, and compartments for storing records and accessories. The sound-arm 5 carries below it a flexible arm 27, Fig. 5, provided with a point 28 which is adapted to engage a spiral guiding groove 19 in the underside of the turntable 4, Fig. 4, to cause the sound-box to be traversed across the wax blank on the turntable when the recording stylus 47 is operative. The turntable may be made of galalith. In order to lower the sound-box 26 on to the blank simultaneously with the bringing of the point 28 into engagement with the guiding-groove 19. a pivoted cam 29 is provided on the arm 5. This cam acts both upon the arm 27 and, through a transverse pin 34. upon a rod 35 attached to the tubular part 36 on which the sound-box 26 is mounted. This part 36 is pivoted between screws 25 on a T-shaped portion of the sound-arm 5. The latter also carries a pointer 42, the end of which moves over a scale 43. This device facilitates the placing of the sound-box at the correct starting-point, and the setting of the sound-arm 5 in any definite position required. Instead of allowing the soundbox 26 to bear on the blank by its weight alone, it may be subjected to pressure by a spring. The reproducing sound-box 51 is carried by the soundarm 6 which is mounted in a holder 53, pivoted on a pin 54, Fig. 9. This pin is supported on a forked part 55, itself rotatably carried by a pin engaging a bearing 52. A weighted balancing arm 57 extends from the member 55 under the sound-arm 6. The end of the arm 6 near the pivot is bent obliquely, and is adapted to receive a detachable horn 23. The same horn can be used for recording, by fitting it on to the end part 22 of the sound-arm 5. A flexible horn of cellulose acetate or the like is preferably used. Instead of using a horn for sound-reproduction, a rubber tube 60 fitted with ear-pieces 61 may be attached to the sound-arm 6. The tube 60 may be provided with a metal clip 62 adapted to engage with a fixed plate 63. Instead of providing the guiding groove 19 on the turntable itself, it may be formed on a separate plate mounted below the turntable; or the groove may be formed in the underside of the record blank consisting of a metal base having a coating of record composition and carrying a. small tube for fitting on the motor spindle. The reproducing sound-arm may, like the recording-arm, be provided with a guiding arm coacting with a groove on the turntable.