GB134738A - - Google Patents

Abstract

134,738. Wade, H., (ãolian Co.). March 11, 1919. Returning sound-box to starting-point; raising, lowering, and positioning sound-boxes.-In a repeating-device for gramophones &c., the tone-arm is lifted at the end of a reproduction by the engagement of a driving-roller beneath a curved platform secured to the tone-arm, and the frictional contact of the driving-roller returns the tone-arm to starting position. The driving-roller is mounted on a tilting shaft controlled by an electro-magnet, which is energized at the end of a reproduction, and is de-energized after the return of the tone-arm, by switches actuated by the tone-arm. Fig. 1 is a plan of the mechanism with the top-plate removed, Fig. 2 is an elevation, and Fig. 6 shows a detail of the switch-actuating device. A bent rod 12 secured to the tone-arm 4 projects through, a slot in the cover-plate 2 and carries at its lower end a curved platform 14. Beneath the platform lies a roller 21 mounted on a shaft 19 which has its bearings in a yoke 16 pivoted on pins 17 to fixed pillars 15. The other end of the shaft 19 carries a friction roller 20 lying over the upper face of a toothed wheel 8 which forms part of the driving-gear between the spring motor and the turntable spindle 9. An arm 22 on the yoke 16 is pivoted to the core 54 of a solenoid 23, a spring 24 normally holding the core in its outer position, and maintaining the roller 20 out of engagement with the wheel 8. At the end of a reproduction, the tone-arm engages a switch-actuating member 39 and closes a switch 27 in the circuit of the solenoid, which thereupon attracts its core 54 and tilts the yoke 16. The roller 21 engages and lifts the platform 14, thus raising the sound-box off the record. The roller 20 engages and is rotated by the wheel 8 and the platform 14 is thus moved in a horizontal direction, returning the sound-box and tone-arm to its starting-position. Meanwhile the solenoid circuit is maintained through a hold-on contact carried by an armature beneath the solenoid. The holdon contact is in series with a normally-closed switch 30, and when the tone-arm reaches the starting-position, the contacts 30 are opened, the solenoid de-energized, and the sound-box lowered on to the record. The core 54 moves in a cylinder with an air-escape hole in its base, thus cushioning the descent. The switch-actuating members for each switch comprise a horizontal slidable rod 38 with an upturned end 39 pressed towards the tone-arm by a spring 46. The movable switch spring 27 or 30 is carried by an arm 33 pivoted at 34. The rod 38 passes through an oval hole in a vertical pin 36 which slides in the vertical direction through the arm 33. A spring 40 presses the pin 36 downwards and gives a frictional grip between the arm 33 and the rod 38. This grip may be released by depressing a plunger 43 connected by a lever 41 to the lower end of the pin. The rods 38 can thus be adjusted to the points for starting and finishing a reproduction.