GB568039A - Milling and like machine tool - Google Patents

Abstract

568,039. Variable-speed gearing. TANDLER, W. S., and WALKER, D. S. March 10, 1943, No. 3886. [Class 80 (ii)] Also in Groups XXII. XXXVII and XL] In a milling &c. machine for producing shaped work-pieces, the work-table is traversed continuously and the cutter slide is given a transverse movement relatively thereto under control of two rotating cylinders driven in synchronism with the respective feeds and carrying light-reflecting indicia which operate through photo-electric cells. The work-table 22, Fig. 1, carries a feed screw 84, Fig. 3, engaged by a nut 82 driven by toothed gearing 80, 74, worm gearing 70 and pick-off gears driven through shaft 60, from an electric motor 56. Rapid traverse may be given to the table by disengaging the gear 74 from the wormwheel 72 and clutching it to spiral gears 64 driven directly from the shaft 60, the clutch being operated by a rod 86 actuated through lever 96 by a solenoid 90. The cutter 32, Fig. 1, is driven by a motor 30 through pickoff and bevel gears 42, 48 and is carried in a head 26 vertically adjustable on a column 24 by a screw 108 which is driven through worm gearing 106, Fig. 6, from a motor 100 on the column. A controlling cylinder 149 carrying light-reflecting indicia is mounted on a frame 148 screwing at 152 on a stationary pin 150 so as to have an axial motion during its rotation and cause the scanning beam of light to traverse a helical path thereon. The frame carries an internal gear 158 adapted to be driven from the worm-wheel 106 always in the same direction in spite of reversals of the feed screw 108. the gear meshing with a pinion 160, secured to one side-wheel 164 of a differential train. The other side-wheel 166 is driven by the screw 108 and the planet pinions 170 are mounted in a carrier 174 keyed within a sliding clutch sleeve 182. Upward motion of the latter causes it to be held stationary against a socket 184 of the machine framing 24, in which case the bevel gears 164, 166 rotate in opposite directions and the cylinder 149 rotates in the opposite direction to the screw 108, whilst downward movement of the sleeve 182 clutches it at 180 to the worm-wheel 106, the epicyclic train being then locked and the cylinder 149 rotating in the same direction as the screw 108. The clutch sleeve is moved axially by a yoke 190 actuated through yielding linkage from a solenoid, provision being made for locking it by hand in an intermediate position to disconnect the drive from the cylinder 149. This allows the cylinder to be rotated by hand for rapid return to starting position, or allows the machine to be used for normal milling operations without rotation of the cylinder. The second control cylinder 112, Fig. 1, is driven through bevel gearing and shaft 126 from the gear 80 which the table traversing nut 82.