GB660781A - Improvements in or relating to lathes - Google Patents

Abstract

660,781. Lathes. VICTORIA MACHINE TOOL CO., Ltd., FRYE, J., and SELBY, J. Dec. 29, 1947 [Nov. 27, 1946], No. 35174/46. Class 83 (iii). Feed mechanism for the apron and saddle unit of a lathe comprises a mechanical transmission through which the unit may be power fed longitudinally, means operated by the engagement of a trip element disposed on the unit with a stop to interrupt the feed transmission on the unit reaching a given limit and hand means by which the longitudinal feed may be continued for a small distance subsequent to the interruption of the transmission until the unit is brought to a positive stop on reaching a further limit. The longitudinal feed of the apron and saddle unit 3, Figs. 1 and 4, is effected from the usual feed shaft 7 and a sliding pinion 14 thereon to another pinion 15 on a parallel shaft 16 with. in the unit. This shaft carries a worm 17, engaging a large worm wheel 18 integral with which is a pinion 19 driving a relatively large toothed wheel 20. The latter revolves loosely on a transverse shaft 21 when the feed is disengaged, a pinion 8 being secured to the rear end of this shaft meshing with a rack 9 secured to the machine bed. A cap 22, Fig. 4, fits over the outer end of shaft 21 and serves through thrust bearings and against the pressure of springs 30, to bring a clutch face 24 on an intermediate splined sleeve 23 into engagement with a clutch face 25 provided on the wheel 20, thus inward movement of the cap-piece 22 engages the longitudinal feed. The wheel 20 is also connected through gearing and similar clutch members 41, 42, Fig. 6, to operate a screw controlling the transverse feed of the tool, in this case the clutch members are operated by a cap-piece 39. The latter is operated by a lever 48 provided with a camend and an anti-friction roller which rotates loosely about a shaft 27. A similar cam-piece and roller is secured to this shaft to operate the cap-piece 22 and longitudinal feed. The latter is tripped by an adjustable stop 58 on the bed contacting a plunger 56 on the apron unit the latter being in wedge connection with a cross-rod 60, Fig. 6, for rotating the shaft 27. After disconnection of the automatic feed the saddle may be moved by a hand wheel 62 until the head of the trip plunger engages a hardened shoulder 65 carried by the apron unit which acts as a limit stop. A lead screw 12 with a split-nut in the apron is provided for screwing and the control handle 51 therefore is interlocked with the shaft 27 so that screwcutting and automatic feed cannot be simultaneously engaged. A shaft 71, Fig. 1, runs the length of the machine and a lever 72, slidably keyed thereto is mounted in a gate at the side of the apron and controls the start, stop, and reverse of the driving motor for the machine.