Patent GB-191517178-A (GB)
Title: Improvements in and relating to Talking Machines.
Inventor: ADAIR MONTAGUE
Filed: 1915-12-07
Abstract: 17,178. Adair, M. Dec. 7. Starting and stopping; returning sound-box to starting-point; brushing records; raising and lowering sound - boxes.- A stop-mechanism for a r r e s t i n g the recordcarrier of talking- machines at the termination of a record comprises a brake carried by the sound-box and brought automatically into engagement with the record when the needle reaches the last groove of the record, whatever may be the extent of the zone of grooves. Alternatively, the sound-box may carry an obliquely-mounted roller, which, when allowed to fall on the rotating record, applies the brake indirectly by moving the tone-arm beyond its playing position. Figs. 1 and 3 are elevations of the mechanism in normal position, Figs. 4 and 5 show the mechanism with the brake in action, and Figs. 8, 9, and 12 show modifications. A ring- shaped frame 9, placed around and secured to the sound-box 6<a>, has an arm 10 which projects upwards in front of the diaphragm and forms a pivot for the brake lever 13. One arm of the brake lever is normally retained in vertical position by a catch 25, and the other arm is formed with an eccentric sector carrying a rubber block 15 and a leather or like block 14. The catch 25 is secured to a vertical sleeve 19 arranged to turn on an horizontal pin 20 carried in a bracket 12 on the frame 9. Through the sleeve 19 passes a rod 21 with a weight 23 at its upper end and a flat brush 22 or the like at its lower end. The bristles are cut obliquely, as shown in Fig. 3, and the brush is so placed that the stylus either precedes or follows the engaging point of the brush as it moves inwards during the playing of a record, the weight 23 tending to keep the parts in the position shown. During this inward movement of the tone-arm, it engages the vertical arm 34 of a counterweighted lever 31, and when the needle reaches the last groove of the record, the counterweight is sufficient to prevent further inward movement. As the brush 22, however, is still fed inwardly by the grooves, the sleeve 19 and rod 21 are tilted into the position shown in Fig: 4, thereby withdrawing the catch 25 and allowing the brake to fall on to the record. As the rubber block 15 engages, the needle, sound-box, and goose-neck are raised, and the record is subsequently arrested by the friction of the block 14. In order to reset the device, the goose-neck is turned about its pivot by grasping finger-pieces 24, 24<a> secured to the frame 9 and sleeve 19 respectively. With the sound-box in inverted position, the arm 13<a> of the brake lever engages behind the latch 25, and the weighted rod 21 slides through its sleeve 19. When starting another record, the rod 21 is held with the brush raised by a spring projection 24<b> on the fingerpiece 24<a>, thus allowing a clear sight of the needle. When the machine is inoperative, the tone-arm is supported on a ledge 29 carried on a lever 28<a>, which is pivoted on a pin 27 and carries at the end of its horizontal arm a brake block engaging the underside of the turntable. In order to return the tone-arm automatically into position on the ledge 29 at the completion of a record, the braking- block 14 may be replaced by an obliquely-mounted roller 14<a>, Figs. 8 and 9, which rolls on the rotating record when droppe thereon, and so traverses the tone-arm outwards. When the tone-arm is over the ledge 29, the roller reaches the turntable rim and runs on to a ledge 28 for ned on the brake lever 28<a>. Alternatively, the roller may arrest the table by its frictional resistance before it reaches the rim. The roller 14<a> may be mounted obliquely in the opposite direction, and its rolling action then causes the tone-arm to move further inwards, thereby bringing brake blocks into engagement with the turntable rim. In the arrangement shown in Fig. 12, an inwardly-running roller 14<b> is used, and the tone-arm is fitted with a bracket 39 carrying two brake blocks 35, 38, which engage the turntable rim when the tone-arm is moved in either direction beyond the playing position. A weighted bell-crank lever 41 pivotally mounted on the bracket 39 offers a resistance to the inward movement of the tone-arm when its vertical arm engages a fixed stop 37.