7740. Boudet, E. E. L. March 30. Lathes; screwing; tapping.-Full automatic turret lathes have a stop-motion operating on the exhaustion of the stock, a two-speed cam shaft, traversing and parting slides, and a laterally moving turret-slide with screwing, tapping, and drilling apparatus. A hollow spindle 35, Fig. 1, has a chuck operated at 36 and an internal feedsleeve 38 operated by a slide 40 with cam-bowl 42. When the'stock is exhausted, the slide 40 is moved back against a stop 46 by a weight 43, thus withdrawing the bowl from the path of the cams. It is stated that the weight 43 may also be employed to disengage the intermediate gearing described below. The cam-drum is driven from a speed cone 120, Fig. 2, on a shaft carrying an oil-pump pulley 119, through a clutch 116, bevel-gearing 112, and worm-gearing 110. The casing 113 contains epicyclic gearing operated from the disk 11 to give a fast or slow speed as required. A siddle 47 with slides 48, 49 is controlled by cams 16, 17 and though normally fixed on the bed may be connected with the traversing-bar 53 of a corresponding saddle 52 by a bolt at 61. In this case the cams 16, 17 are connected at 22 to slide with the cams 20, 21 as controlled by the bracket 19 on the saddle 52. The turret-slide 62 is traversed laterally at 105 by a spring-controlled cam-lever 100 and is locked in position by an index bolt 89 passing through holes in the slide and in a tempered steel plate 98 let into its bottom face. The screwing or tapping spindle 71 is splined to an internal hollow spindle 79 which carries the die or tap holder and is provided with an adjustable abutment screw for the cam-lever 64 and with a screwed sleeve 82 for operating the clutch 76. The initial position of the cam-lever 64 is determined by a spring 66 and stop 65, and the return movement of the spindle 79 by the spring 84 is limited by a stop 81. Rings 78 prevent end movement of the spindle 71 which is driven in the same direction as the constantly rotating spindle 35 by a clutch 76, operable by a cam-lever 86 to engage pulleys 72, 73. The pulley 73 runs slower than, and the pulley 72 faster than, the spindle 35. The development of the clutch faces is shown in Fig. 6. The clutch 74 of the pulley 72 has only one tooth, formed by a helical projection occupying the whole circumference, to enable the pulley to be gradually thrown into gear during a revolution. The other face has a double projection, the part 121 driving initially and the part 122 preventing overrunning due to the drag of the faster-running work spindle during the tbreading-operation. When the required length has been threaded, the sleeve 82 engages internally projecting pins 77 and frees the spindle, which rotates with the work until the lever 86 throws the clutch over to the pulley 72 for unscrewing, after which it returns it to the pulley 73. The tool spindle 94 is similarly arranged, except that it does not rotate. The turret-slide may be arranged to carry more than two spindles, and additional traversing-slides may be provided. The improvements may be applied to a lathe which is not entirely automatic but which is adapted for finishing forgings, castings, and other articles.