Patent GB-261360-A (GB)
Title: Automatic lathe
IPC: B23B7/02
Filed: 1926-10-29
Abstract: 261,360. Mulka, F. Nov. 16, 1925, [Convention date]. Lathes; chucks.-In an automatic lathe, the tools are radially arranged on a fixed head and are moved towards the work by means of cams mounted on a rotating feedring. The bed 2 is mounted on an under-frame 1 and carries the fixed head 3 which supports the front end of the hollow work-spindle 5 driven by a belt passing over guide-pulleys 6 and driving pulley a. The tools are carried on the head in holders 12 - - 12<c> of which the holders 12, 12<a> carry forming tools, and the holders 12b, 12<c> parting-tools. The tools are fed simultaneously by means of a feed ring 4 which is driven through gearing 9 from a beltdriven shaft 8 and which is provided with grooves 4<a> - - 4d adapted to receive the adjustable toolactuating cams 11 - - 11<c>. The turret 14 is mounted on a slide 13 actuated by a rod 15 which carries a series of cams 18 - - 18b which may coact with rollers 17 - - 17<c> adjustably mounted in a series of holes in the feed ring, to reciprocate the turret slide, the return movement being effected by a spring 19. At the end of the withdrawal movement of the turret one of the pins 41 engages an arm 42 thus compressing a spring 43. At the same time a pivoted lever 44 engages a stop 45 to withdraw the locking-bolt against a spring. The spring 43 then acts to rotate the turret and at the commencement of the forward movement the locking-bolt is released to engage the next notch. For cutting screw-threads the adjustable cam-member 18<b> is used to traverse the turret at the required speed. The driving-pulley a of the work-spindle embodies epicyclic, twospeed gearing. The planet pinions c, c<1> engage an eleven-tooth wheel d keyed to the workspindle, and a ten-toothed wheel f secured to the cone e. For the direct drive at high speed the cone is engaged with the pulley by means of a ring i acting through levers h while for a 10: 1 reduction the cone is disengaged from the pulley and held stationary by a pawl g engaging a toothed rim g'. The ring i is operated through a rod 21 by rollers 20, 20<a> adjustably mounted on the feed-ring extension 40. The shaft 8 which drives the feed-ring is also operated through a two-speed epicyclic gear operated through a sliding rod 26 by rollers on the feed-ring. The work gripper comprises chuck-jaws 30 which are closed to grip the work by a conical member 29 moved axially by a sleeve 28 operated through bell-crank levers 24<a> from a fork 24. The latter is actuated by a roller on the feed ring acting through an axially sliding rod. When the chuck jaws are opened the work advances by gravity up to a stop fixed in the turret and is then moved backwards to the working position by the advance of the turret, this arrangement ensuring that there is a sufficient length of stock for the chuck to grip firmly when the end of the stock-bar is reached. The Specification as open to inspection under Sect. 91 (3) (a) states that the fixed head may accommodate a copying-member 31 and, at 32, an arm for holding a centring sleeve, stay guide &c. This subject-matter does not appear in the Specification as accepted.