Patent GB-190520311-A (GB)
Title: Improvements in Engine Lathes.
Inventor: HARTNESS JAMES
Filed: 1905-10-07
Granted: 1906-10-06
Abstract: 20,311. Hartness, J. Oct. 7. Lathes; tools; tool-holders.-A lathe, specially designed for turning bar stock, and having novel types of bed, slide-rest, tailstock, steady rest, and traversing- mechanism, is shown in the Figures. The headstock and bed are cast in one, the latter consisting of an oil pan 51 and a box 52, 53, open only at the bottom, on which the rests &c. slide. The steady rests and tailstock slide in a dovetailed groove 56, from which oil and chip holes 290 lead to the back of the box. The front of the box has a longitudinal groove 230a of rather more than semicircular section for the reception of worm boxes 231, and a groove 58 for the reception of the fixed rack 205 and the pinions 204 on the toolrests 170, 171, 172, 173. The rests embrace the rectangular part 57 of the box, have screw-adjusted gibs 177, Fig. 9, at the back and underside of the part 57, and can be moved past the steady rests and tailstock. The tools 192, Fig. 10, slide in angular holes in bushes 191, and are shouldered and connected at 200 to the shouldered ends of adjusting-screws 196, the bushes 191 being securely held in holes in the rests by pins 193 and cam shafts 194. The rests are shown as being connected in pairs by right and left handed screws 210 which are locked by pins 212 and screws 214, Fig. 10, and, although all the rests have handles 207 for hand traversing, only one of each pair, namely, the rests 171, 172, has power-traversing mechanism. This mechanism comprises spur gearing 227, 226, Fig. 12, and a worm.wheel 228, all carried by a rest, and a worm 229 in a worm box 231. A driven shaft 130, concentric with the groove 230a, passes through each box'231 and carries a splined wheel 232, while the shaft 230 carrying the worm 229 and a wheel 233 is eccentrically mounted in a bushing 235 having arms in which is pivoted an idle wheel 234 always gearing with the wheel 233. In one position of the bushing, the wheels 232, 233 are in gear as shown in Figs. 5 and 12, and the rest is traversed in one direction, while in the other position of the bushing the wheel 234 is brought into action, as shown in Fig. 19, and the rest is traversed in the opposite direction. A latch 637, pivoted on the shaft of the wheel 234, engages a pin 240 on the worm box or hooks over the shaft 130 in one or other position of the bushing. Each box 231 has a handle 642, and when raised is retained by a narrow spring bolt 245 which may be withdrawn by rotating the cam disk 250. When the resistance to the traverse of the rest is excessive, the worm 229 and the box move axially against the action of spring-pressed pins 252 uotil the catch 244 is free of the bolt 245, when the box falls and disengages the worm and wheel 229, 228. The tailstock has a tapered gib 265 adjusted by a screw 266, is secured in the groove 56 by V-blocks 269 and bolts 270, and has a prismatic centre-carrier 273 which is operated by a screw and handle 286 and locked by sliding blocks 277 and bolts 278. The steady rest shown in Fig. 12 comprises rollers 313, 314 mounted in adjustable blocks in a bracket 305 pivoted to a base 301 secured in the groove 56 by a V-block 302 and a bolt 303, the bracket being secured by a pin to the base when the rest is in use. The steady rest shown in Fig. 5 is pivoted at 336 to a slide 331 on the top of a slide-rest, the bracket 335 being locked by an eccentric pin 339 when the rest is in use.