Patent GB-917158-A (GB)
Title: Improvements in stock-feeding mechanism for automatic lathes
IPC: B23B13/00
Filed: 1959-07-24
Abstract: 917,158. Automatic lathes; bar-stock feeds. USINES TORNOS, FABRIQUE DE MACHINES MOUTIER S.A. July 24, 1959 [July 26, 1958], No. 25447/59. Class 83 (3). Bar-stock feeding mechanism for sliding- headstock type automatic lathes includes a guiding device behind the headstock to support a stock bar, pusher-means within the guiding device which prevent backward movement of the stock on rearward movement of the headstock, driving- means to move the pushermeans rearwardly and gripping-means on the pushermeans for holding a waste end of stock for moving it backwardly for disposal when the pusher means is in the rearmost position. The sliding headstock 3, Fig. 1, carries a stock-bar 49 which is supported by a centre-rest 50 mounted in a frame 4 carrying a " fan " arrangement of cutting tools 51. Further endworking tools are carried in an auxiliary head 5. The feed of the headstock-tools and stock is controlled by an independent-drive cam-shaft 7, Fig. 4, arranged at the back of the machine and driven through a pulley 60, gears 62, 63, clutch 63a, 63b, worm 58 and wormwheel 59. The headstock is moved by a lever 9, Fig. 1, operated from the cam-shaft 7, which moves a bell-crank lever 12 carrying an adjustablestroke fulcrum-pin 14 which engages a vertical face on a block carried by the headstock. Spindle and chuck. The headstock spindle 16, Fig. 2, driven independently by the pulley 20, is hollow to accommodate the axial-fed bar-stock and has a taper-closing collet chuck 21 which is closed by a taper - ended sleeve 22. A spring 44 tends to " open " the chuck and closure is effected by a further sleeve 23 operated by the ends 25a of double-armed levers 25. The latter are moved to close the chuck by a further two-part sleeve 27 sliding on the outside of the spindle 16 and having the outer part 29 rotatable through a ball-race 30 relative to the inner part. The outer part is moved by pins 34 carried by a bell-crank lever 31, the outer arm 31b of which has a pin 35 engaging a groove 36 in a rocking member 37. The latter is moved to open and close the chuck by tappet members 41, 43, on the cam-shaft 7 engaging projections on the rocking member 37. Bar-stock feed. Bars 155, Fig. 15, are fed one-at-a-time through an escapement 156, 159 from an inclined magazine 154 to a tubular support 109, 110, in alignment with the spindle. A pusher 69, carried by a rod 65 supported in the inner member 109, Figs. 5 and 7, is operated by a weight 70, Fig. 1, and pulley system to feed the stock through the support and spindle, the cutting-off tool being used as a stock-stop for a new length of bar. The part 110 is rotatable relative to the part 109 and is cammed by the pusher in its rearmost position to bring slots in the members into correspondence to provide gaps 109a, 110a, Fig. 10, for entry of a new stock-bar and gap 109b, 110b for discharge of a waste end of bar by gravity. The stock-bars have prepared ends 114, 115, 116, Fig. 14, which fit into a recess in the end of the pusherbar 65. The latter has spring-ends 112 which make the waste end of the bar to be drawn back when it is no longer held by the chuck. When the pusher-bar 65 reaches a forward position where the remaining length of stock is insufficient for another workpiece it operates against a stop member 79 which controls a mechanical linkage and switchgear to stop the cam-shaft and set in operation an electric motor 75, Fig. 1, which pulls back the pusher 69 and the waste end of stock, at the same time raising the weight 70. The motor is stopped and the controls for a new cycle started when the pusher contacts a switch 105, Fig. 5. Specification 827,417 is referred to.