Patent GB-528867-A (GB)
Title: Improvements in or relating to lathes and tool holders therefor
IPC: B23B29/24
Filed: 1939-05-16
Abstract: 528,867. Lathes. SIMS, A. L. May 16, 1939, No. 14579. [Class 83 (iii)] A tool-holder for a lathe or like machine comprises a box-like unit having cam tracks controlling the movement of one or more pairs of followers having an outline similar to the cam tracks, each pair of followers being connected to a member which supports one or more tools. In one form a base frame 1 secured to a lathe rest 2 carries on either side of the centre line box-like units A and B consisting of plates 4, 5, having vertical flanges bolted together to form a cam track engaged by rectangular followers 7 secured to pin members 9 provided with lugs 8 to which one or more tools 8<SP>1</SP> may be secured. Extensions 10 of the followers engage in rectangular grooves 11 in the plates 4, 5, to maintain the followers against the cam track. Two or more tools may be supported on one follower so that they make successive cuts of different lengths or depths or successive cuts may be made by tools on different followers. In Fig. 1 two tools are mounted on each of two followers in unit A and a single tool is mounted on are one follower of unit B. The followers the moved round their tracks by slotted discs 12, 12<SP>1</SP> engaging the pins 9 and driven from a cross shaft 22 through worm gearing 21 and spur gearing 17. The plates 5 have threaded bosses 35 engaged by worms 36, 37 for adjusting each unit round a vertical axis to adjust its cam track relatively to the centre line of the lathe. The tools of unit A come into action while the follower engages the longitudinallyextending surface 23 of the cam track while unit B carries a parting tool which acts during the movement of the follower along the transverse surface 24. When the parting tool reaches the end of the ensuing longitudinal movement, Fig. 4, it may act as a stop to determine the feed of the work. By forming the front wall of the box with a suitable curvature, similar curved profiles may be formed on the work. The action may be made automatic by connecting the driving member to the lathe drive. In another modification, Fig. 5, the parting tool may be actuated from a handle 27 after the required cuts have been made by the tools of the unit A. In a further modification the followers may be actuated by an endless chain. By acting on stationary work key-ways, grooves or splines may be cut. Another modification, Fig. 6, provides means for cutting two tapers and also for parting off the work. In another modification Fig. 10 one of the tools may perform a shallow boring operation and the other a facing operation. Alternatively the tools may be arranged for deep internal turning. The mechanism may also be adapted for screw cutting, the slots in the discs being designed so that the speed of the followers is maintained constant and has the required relation to the spindle speed. Or the whole unit may be moved parallel to the lathe axis like an ordinary tool holder. In a further modification, Fig. 12, several groups of tools may be attached to successive followers so that each group deepens the cuts made by the preceding group.