Patent GB-678913-A (GB)
Title: Improvements in single spindle automatic lathes
IPC: B23B7/04
Filed: 1947-07-07
Abstract: 678,913. Lathes. FAIRWEATHER, H. G. C. (National Acme Co.). July 7, 1947, No. 17894/47. Class 83 (iii). [Also in Group XXIV] A single-spindle automatic hydraulically - controlled lathe, convertible for use as a bar or chucking machine, comprises cross-slides 10... 12, Fig. 1, disposed about the spindle 21, an indexible slide-carrying tool-turret 9 having its axis parallel to the spindle, and hydraulicallycontrolled stock feeding and chucking means. Beds and framings; cuttings, removing; headstocks; reversing - mechanism.-The lathe is completely enclosed and a chip-clearing space 20 is provided. An electric motor 5, an electric motor 6 driving a hydraulic pump and an oil sump 7 are grouped at the rear of the bed. The motor 5 rotates the spindle 21, Fig. 5, carried in roller bearings, by a chain 29, Fig. 2, change gears 32, 33, gears on shafts 34, 37 and a gear 38. A clutch on the shaft 34 is controlled by a valve actuated from a camshaft 68, to give two spindle speeds. The spindle may be reversed by replacing a gear on the shaft 37 and interposing an idle wheel in the drive from the shaft 34. A gear 47 on the shaft 34 rotates, through worm-gearing which incorporates a friction safety device and a slow-feed clutch, a cam-disc 59, Fig. 2, which feeds a cross-slide 10 through an adjustable cam 60 and a lever 61. The disc 59 is linked by an idle-gear 63 to a cam-disc 67 on the shaft 68 controlling the movements of a cross-slide 11. A fast idle-movement of the cam-discs is provided by the motor 6 driving through its shaft 153, Fig. 10, gear 156, shaft 157, fastreturn clutch 158 and a tensioned chain-drive 160, (see Group XXIV), to a shaft 55 forming part also of the slow-feed drive. The shaft 68 also carries a cam-drum controlling, through follower-levers, a gang of four hydraulic valves. One of these valves controls a piston which actuates, in unison, the slow-feed and fastreturn clutches. Cutting-off mechanism; adjustments for wear.-A second valve supplies fluid to a piston 78, Fig. 8, which feeds a top-slide 12, carrying a cutting-off tool, against a spring 79 in slides adjusted for wear by a gib 80. The feed is regulated by a cam which moves with the slide and actuates a hydraulic valve, The cross-slide 10 may be used instead for cutting- off. A fourth slide may be fitted at 18, Fig. 1. Turrets; selector mechanisma.-A third valve controls a piston 85, Fig. 22, which feeds the turret-slides by means of a collar 82 on a rod 84, prevented from rotating by an arm 104 fixed thereto, engaging a member 83 on the appropriate slide. Mounted on a shaft 99, Fig. 24, parallel to the rod 84 is a selector bar 98 carrying dogs 97. The bar is advanced with each slide by a yoke member 106 pivoted at 108 and moved by the arm 104. Each dog 97 actuates a valve V7<SP>1</SP> to regulate the feedmotion of each slide. The turret is indexed by a hydraulic motor 15, Fig. 19, driving, through gearing, a gear 122 keyed on a hollow shaft supporting the rod 84. A valve actuated by the cam-shaft 68 advances a piston 110 to withdraw a locking-bolt 114 from a recess 115 in a disc 116 and to allow rotation of the motor 15. The face X of the disc 116 curves inwardly towards the entry of each recess 115 so that the locking-bolt, urged by a spring 123, progressively moves the piston 110 as the next station is approached. The piston 110 is notched to cut-off the pressure to the motor 15 gradually until the bolt seats in the recess and the motor is stopped. The selecto-bar 98 is indexed with the turret by a chain engaging sprockets 100, 102, Figs. 22 and 24. Barfeed; chuck8; gauging-devices.-A fourth valve controls a piston 147, Fig. 18, and, through a by-pass valve, a piston 130. The piston 147 moves a block 145 engaging a yoke 141 actuating a sleeve T, Fig. 5, to expand toggle-links B<SP>9</SP>, thus sliding a sleeve X to close a bevelled collet Z. The piston 130 then retracts a carriage 127 which is moved forward after the next cycle by a spring 131 to feed the stock by means of a member V through an amount determined by a rear-stop 134 and a stock-stop 22, Fig. 1, on the turret guides. Lubricating cutting tools.-A pump 176, Fig. 10, driven by the shaft 157, supplies cutting- oil.