Patent GB-449642-A (GB)
Title: Needle-changing device for sound reproducers, such as gramophone sound-boxes and pick-ups
IPC: G11B3/46
Filed: 1935-06-20
Abstract: 449,642. Gramophones. BOUSSEL, A., 8, Rue Saint-Guillaume, Courbevoie, Seine France. June 20, 1935, No. 17696. Convention date, June 20, 1934. [Class 40 (ii)] Relates to needle-changing devices for sound-reproducers, such as gramophone sound-boxes and pick-ups comprising a needle holder, the grip of which is controllable, a needle magazine mounted on the support for the device and an inserter feeding needles from the magazine to the needleholder. According to the invention, the needle-holder has a double control, one control causing ejection of the used needle as the reproducer is lowered towards the inserter and the other control causing, by abutment of the reproducer against the inserter at the end of its downward displacement, instantaneous gripping of a needle fed by the inserter. As shown in Fig. 1, the pick-up casing 4 is movable by a handle 6 about a pivot 5 on one end of an arm 1 pivoted at 3 on a vertical spindle 2. The needle 7 is held in a split tube 8 the parts 8<1>, 8<2>, Fig. 4, of which are mounted on pins 9<1>, 9<2> carried respectively by levers 10, 11 pivoted at 12 and 15 respectively. Adjacent ends of the levers are connected by a link 13 and the levers are adapted to be held in the closed position by a spring 16 and in the open position by a detent 17 which engages the end 11<1> of lever 11. A bell-crank lever 20 is pivoted at 21 on the casing 4, the nose of the lever engaging with a, ratchet 23 on the spindle 5, a spring-controlled pawl 24 holding the ratchet during pivoting of the casing 4 in the direction f<4>. After playing a record, the casing 4 is brought above a needle inserter 30, Fig. 6, and the handle 6 turned in the direction f<4> so as to move the casing 4 about its pivot 5. Such movement causes the lever 20 to be moved by one of the ratchet teeth acting as a cam so as to act on the lever 10, thus opening the levers 10. 11 and allowing the needle 7 to be ejected by a spring, the levers being retained in their open position by the detent 17. The casing 4 is then pressed downwardly, the whole of the arm 1 turning in the direction f<2>, Fig. 1, about the pivot 3 until a lateral pin 40 on the casing engages a guide groove on the needle inserter and a hole in the base of the casing is engaged by a lug 43, Fig. 6, on the inserter. Towards the end of its downward movement, the casing depresses a spring pressed plunger 34 which carries a pivoted catch 35 which in its turn depresses a spring pressed plunger 32 in a passage 38 in which a new needle is placed point downwards by a magazine 31. After the catch 35 has been moved downwards a certain distance it is engaged by a stop-pin 36 and is rocked thereby free of the plunger 32 which is urged upwards by the spring 33 so as to insert the new needle into the holder 8. At this moment the tail of the detent 17 encounters the face of the inserter so as to release the levers 10. 11 and close the holder 8. In modified constructions, movement of the levers 10, 11 into the open position may operate a bell-crank lever pivoted on the holder or a spring-pressed plunger slidably mounted in the holder to bring about ejection of a used needle. To facilitate insertion of a needle, the entrance to the holder may be internally countersunk and the upper end of the needle may be cone-shaped. The plunger 34 may also act on one end of a pivoted lever having the plunger 32 pivotally connected to its other end. The magazine 31 containing the fresh needles may be of flattened U-section, Fig. 9, the needles bearing by their body portions on longitudinal flanges 46<1>, 46<2> therein. The needles are held in the magazine before same is placed in position by removable end plugs and bands. The magazine fits at one end into the inserter 30 and is held in place by a spring-controlled sliding clasp 47 engaging over its other end. A spring-controlled retractible thrust member 48 carried by a rod 49 projects into the magazine so as tu engage against the last needle therein. Various minor modifications in the construction of such a magazine are described. According to further modifications, each needle may be formed with a flange engaging in longitudinal. grooves in the magazine, notches in the needles may be engaged by longitudinal flanges in the magazine or the points of the needles may rest on a band of soft material on the bottom of the magazine. The magazine may also be formed with several longitudinally extending parallel compartments each containing a row of needles, one compartment replacing another by suitable displacement of the magazine. A needle reservoir, Fig. 23 (not shown), may, alternatively, be employed. Fig. 22 shows a still further modification in which the needles 7 are carried by a band 80 adapted to unwind from a bobbin 81 over a roller 82 on to a spring wound bobbin 84, each needle abutting against a stop 91 until it is expelled by the inserter plunger 32.