GB511097A - Improvements in chucking and feed devices for lathes and allied machines - Google Patents

Abstract

511,097. Turning; chucks. FORKARDT, R. July 26, 1938, No. 22246. Convention date, July 26, 1937. [Class 83 (iii)] Bar-feed spindles.-In a lathe or like machine having a bar-feed through a hollow spindle, feed members and clamping jaws are mounted in the chuck adjacent the working point and are both operated by fluid-pressure pistons within a cylinder located at the rear end of the spindle. The machine spindle 1 carries a chuck 2 having jaws 12 operated by bevelled surfaces or an axially sliding ring 10 which is attached to a sleeve 13 within the spindle and carrying a piston 8. Radially movable yielding plungers are located in the chuck between the jaws 12 and are coupled thereto by levers &c. so as to engage feed fingers 19 and press them against the work when the chuck is opened. The fingers 19 are removably attached to a sleeve 20 within the sleeve 13 which carries a piston 9. The pistons 8, 9 are slidable within a double cylinder 3 attached at 4 to the spindle 1 and supplied with fluid by either of the pipes 6, 6a leading to a distributor 5 and a four way cock 7. In operation, when fluid is admitted to the pipe 6 it flows by passages 21 first, to the space C to open the chuck and apply the fingers 19 to the work, and then by restricted passages 22 to the space A to feed the work forwards until the piston 9 engages the end of its cylinder or the work engages a stop. Actuation of the cock 7 then connects the pipe 6 to exhaust and the pipe 6a to supply, whereby fluid first flows by passage 23 to space D to close the chuck and release the fingers 19 and then by restricted passages 24 to space B to withdraw the fingers axially. The restricted passages 22, 24 ensure the sequential operation of the gripping and feeding means. If the stroke of the piston 9 is insufficient to feed the work the requisite amount, more than one stroke may be made and the plungers which actuate the fingers 19 radially may be operated directly from the sliding ring 10 instead of through levers. The stationary distributor 5 may be located at the left of the cylinder 3.