| 摘要 |
917,159. Lathes; chucks. USINES TORNOS, FABRIQUE DE MACHINES MOUTIER S.A. Nov. 5, 1959 [Nov. 6, 1958], No. 37530/59. Class 83 (3). An automatic lathe comprises a sliding headstock 3 for feeding and rotating a stock bar 6, tools 17 arranged in front of a fixed or moving sleeve 20 through which the stock is fed, and guiding and pushing means for controlling the stock. The headstock 3 is carried on a slide 7 moved against a spring by a cam, on a shaft at the rear of the lathe, acting through a lever 8, a crank 9, carrying a pin 12, and a block 13. The pin 12 and block 13 are adjustable to vary the position and stroke of the headstock. The tools 17 are fed by levers 18 carrying adjusting screws. A support 5 carries additional tools, such as drills or taps, on a rocker arm or turret, the tools being indexed and fed by a cam on the cam-shaft. These tools may be non-rotary or may be rotated or counter-rotated relatively to the work. When a piece has been machined, it is parted off, released, and the headstock is then moved back to grip a new piece of stock. The stock-bars are carried in tubes of a turret 25, the uppermost tube carrying the operative bar. Each tube has a pusher 26, Fig. 5, that in the upper tube being continuously urged forwards by a pivoted arm 27b on an endless chain 28 moved by a continuouslyenergized motor 31. When a stock-bar has been used as far as possible, the chain returns the pusher and stock-end to the other end of its tube where the arm 27b is released by a ramp 96 and a projection 27a trips a lever 97 to enable a weight 33 on a cord 104 to index the turret. A spring-pressed rod 34, acting on a pawl lever, assists the motor 31 in controlling movements of the stock-bar. Thus, when the stockbar end should be removed and if the friction is too great to enable the motor 31 to withdraw it, in succeeding non-cutting cycles of the lathe, the rod repeatedly moves the stock back twice the distance it is moved forward until the end is free of the frictional holding points, such as the sleeve 20, and can be withdrawn easily by the motor. When all the stock has been used, the stock ends are removed from the turret and replaced by new bars. In a similar way to that described in Specification 917,158, the chuck jaws 71, Fig. 2, are closed by tubular abutting sections 44, 45, 46 moved axially by levers 47 actuated by a rocking lever 53 through a conical sleeve 49, The lever 53 is rocked to close or release the chuck by a cam-grooved lever 59 acted upon by projections 63, 66 on a cam 64 on the cam-shaft 65, the chuck being held by friction in either of its two positions. In a modification, the rod 34 actuates rack-andpinion gearing instead of a pawl lever. |
