Patent GB-124727-A (GB)
Title: Improvements in and relating to Automatic Stopping & Repeating Means for Graphophones.
Inventor: BROOKS CLIFFORD COLLIER
IPC: G11B19/22
Filed: 1919-03-15
Abstract: 124,727. Brooks, C. C., and Klemm, E. O. March 15, 1918, [Convention date]. Returning sound-box to starting-point; starting and stopping, raising, lowering, and positioning sound-boxes. -Gramophones are provided with automatic control mechanism whereby a record may be repeated any desired number of times, or indefinitely, without attention on the part of the operator other than the initial setting of the mechanism. The mechanism is also adapted for machines on which either verticai-cut or lateral-cut records may be reproduced. Fig. 1 is a perspective view of the whole apparatus. Fig. 2 is a plan of the mechanism in the position it assumes when the machine has just been stopped; Fig. 6, a similar plan view, showing the position at the commencement of a reproduction; Fig. 8 shows the brake control, and Fig. 9 is a perspective view of a part of the apparatus. The tonearm E has a universal connexion to the socket 1, and is frictionally gripped by a circular portion 17 of a trip arm 8, the outer end 8<a> of which is bent downwardly to co-operate w i t h inclined planes 16<a>, 16<b>, 16<c> and oblique surfaces 10, 11 for the purpose of controlling the movement of the tone-arm. A horizontal rock-shaft 13, Fig. 9, has secured to it a vertical plate 9 with its upper portion bent into a horizontal plane and shaped as shown. A member 16 consisting of three inclined planes 16a, 16<b>, 16<c> rising to a central apex is attached by a screw 15 to the plate 9. A notch 7 in the part 10 is engaged by the hooked end of a link 4, the other end 5 of which is also hook-shaped to engage pins 3 on a rotary disk 2 driven from the turntable spindle C. The rock-shaft 13 has an arm 37 engaging the end 36 of a sliding spring-controlled rod 35, the opposite end of which is adapted to engage and tu turn a. ratchet-wheel 27 one tooth at a time. The ratchet wheel is adjustable by a handle 30 on its spindle, and a pointer can thus be placed opposite any one of a series of indications on a fixed disk 32. The ratchet wheel has one deep tooth 28 which, when opposite the rod 35, renders this inoperative to turn the wheel. A brake lever 25 operating on the governor disk 23 co-operates at its end 25<a> with the ratchet wheel 27. The placing of the deep tooth 28 under the end 25<a> causes the machine to be stopped. With the parts in the position shown in Fig. 2, the machine is at rest with the sound-box held in an elevated position over the final record groove, by the leg 8<a> resting on the upper portion of the inclined plane 16<a>. The operator swings the tone-arm towards the record centre (to the left in Fig. 2), causing the leg 8<a> to engage the oblique face 10 and pushing it towards the disk 2, thereby disengaging the hook 5 from the pin 3. A spring-controlled arm 40 thereupon moves the hook 5 to the left so that as the tone-arm is moved to the right, the link 4 and plate 10, 11 are advanced by a spring 38 until the leg 8<a> falls into a notoh 12. The tone-arm is now placed so that the needle lies in the final record groove, the frictional. connexion of the ring 17 allowing the leg 8<a> to remain locked in the notch 12. The starting-point indicator 19 is then placed opposite the starting groove of the record. This indicator is frictionally mounted on the tone-arm socket 1 and carries a stop member 20 at one end which co-operates with a lug 22 on the tone-arm forming a limit stop for the outward swing of the tonearm The setting-handle 30 is next moved from the stop position to a position in which the pointer indicates the number of reproductions desired, or to a point marked " continuous." This movement operates the brake lever 25 and per. mits the motor to start. The disk 2 thereupon rotates and a pin 3 engages the hook 5 and draws forward the link 4 and the parts mounted on the rock-shaft 13. The leg 8a is thus disengaged from the notch 12 and rides up the inclined plane 16<a>, thus lifting the sound-box. The leg then slides down the inclined plane 16<b>, and causes the tonearm to swing outwards and to fall until the stops 20, 22 engage, whereupon the needle engages the record at the starting-point and the record is played. After approximately half a rotation of the disk 2 the driving-pin 3 leaves the hook 5, and the spring 42 returns the link 4 to a position shown in dotted lines in Fig. 6, in which the pins 3 do not engage the hook 5. As the record is being played, the leg 8<a> rides on the oblique surface 11 and finally reaches the notch 12. The link 4 then takes up a position in which the pin 3 engages the hook 5 and the link 4 and parts 10, 11 are again drawn forward into the position shown in Fig. 2. During the forward movement of tho link 4, the arm 37 on the rock-shaft 13 engages the rod 35 and steps the ratchet-wheel one tooth forward. If the pointer has been set for one or more repetitions this does not bring the deep tooth 28 under the brake lever 25, and the motor therefore continues to operate. The leg 8<a> rides up the incline 16<a> and down the incline 16<b>, thus raising the sound-box and swing- ing it to the starting-point. After the last repetition, the deep tooth 28 is brought under the brake lever and the machine is stopped with the tone-arm elevated over the last groove, and the leg 8<a> in the position shown in Fig. 2. If continuous repetition is desired, the deep tooth 28 is placed opposite the end of the rod 35, so that the reciprocation of this rod does not operate the ratchet-wheel 27. The repeating mechanism may be rendered inoperative by placing a handcontrolled stop 46 behind the arm 37 on the rockshaft 13, and under these circumstances the brake may be brought into action when desired by turning the knob 30. The movement of the link 4 is controlled by a fixed pin 49 engaging sloping surfaces 4a on the link. When the soundbox is so mounted that it can be turned from a position suitable for lateral-cut records to a position suitable for vertical-cut records, a head 21 provided on the stop-pin 20; and this head is removed when playing vertical-cut records so as to compensate for the different position of the needle relatively to the centre-line of the tonearm.