Patent GB-860719-A (GB)
Title: Method and apparatus for supporting and feeding the work in lathes
IPC: B23Q7/00
Filed: 1958-05-15
Abstract: 860,719. Lathes. ERNAULT-BATIGNOLLES, H. May 15, 1958 [May 20, 1957], No. 15690/58. Class 83 (3). A lathe for operating on chucked work is provided with a rotary and axially - movable hollow auxiliary spindle to receive the work, the spindle having gripping-means for the work and fluid-operated means to move it towards and away from the chuck, and abutment means on the spindle operating valve-mechanism to control the movement towards the chuck. The auxiliary spindle 2, Fig. 1, is arranged opposite the main chuck 102 in place of the usual tailstock, and carries fluid-operated grip-. ping means driven through a freewheel device and pick-off gears from a motor 31. The spindle is movable axially by fluid-pressure within a casing 1, and the movements are automatically controlled by stops 89 to give the required cycle-of-movement. Process cycle.- Considering the first workpiece 100, Fig. 6 (A), ready to be parted from the end of a bar 101, held by the chuck 102, the auxiliary gripping-means 38 is brought into position adjacent the parting- tool 104. Prior to gripping the workpiece, the chuck 38 is rotated by its own motor at a speed slightly less than that of the main spindle, but on gripping the work the main chuck-drive takes over rotation of the auxiliary gripping-means or chuck as permitted by the freewheel drive. The first turning stage, Fig. 6 (B), for a new workpiece is then made by tool 103, and next the finished workpiece is parted off, Fig. 6 (C). The auxiliary chuck 38 then moves automatically towards the main chuck and takes up a new supporting-position, Fig. 6 (D), predetermined by the stops referred to above. After a succession of supporting positions, the auxiliary chuck 38 reaches the end of the exposed bar, Fig. 6 (E). The main chuck 102 is then opened and the chuck 38, still gripping the work, is returned to its initial position, Fig. 6 (F), thus drawing with it a fresh length of bar-stock for a new series of workpieces. Auxiliary spindle; chucks.-The spindle 5, Fig. 2, is supported by bearings 3, 4, in a quill 2 slidable within the fixed supporting-frame 1. The front end of the spindle carries a chuck with radial sliding-jaws 38 moved by cranked levers 36 connected to a rod 35 of a fluid-piston 34. The latter is supplied with pressure-fluid for opening and closing the chuck from a fluid slip-ring device 41, 42, supply-lines 47, 48 and a reversing-valve 99. The near end of spindle 5 is splined to engage a sleeve 8 which is supported in the rear of the casing 1, and carries a freewheel sprocket 20, 21, which is driven by pick-off gears from the electric motor referred to above. The spindle quill is moved by differential fluid-pressure cylinders 13, 14, controlled by a piston-valve 51. The latter is moved, either by an electromagnetic device 67, 68, or by the stops 89 on an extension 72 of the piston valve and co-operating with a stop 90 moving with the quill. Gauging-devices.-The stop-rod 72 is indexible to bring different stops into position by a rack- and-pinion arrangement 74, 75, operated by fluid-pressure.