GB711660A - An improved automatic bar-cutting lathe - Google Patents

Abstract

711,660. Vertical lathes. GUHRING, O., GUHRING, A., and GUHRING, M. April 30, 1952, No. 10894/52. Class 83 (3) A vertical automatic barlathe with one or more hollow spindles rotating in fixed bearings, is characterized in that a common motor drives the spindles through a continuously regulable transmission and also drives, through a stepped transmission, a cam shaft with cams which control the number of strokes per minute of the tool slide or slides and enables the amount of the stroke to be varied by using different cams, independent control means being provided so that spindle speed, tool strokes per minute and amount of stroke may be varied. The machine is similar in general arrangement to that described in Specification 463,592 and comprises two spindles 2, 3, Fig. 1, carried in fixed bearings 50 supported on the vertical column 1 of the machine. The spindles are belt-driven from an electric motor 23 and the speed is variable by a stepless transmission arranged in a casing 21 and controlled by a hand-lever 59. Two slides 5, 6, one for each spindle, are moved up to the work for the cutting operation by levers 8, 9 secured to a common pivotal rod 10 to which a single lever 11 is fixed. The latter carries a follower 13, Fig. 2, which engages one of a series of cams 14 on a shaft 15 driven by worm gearing 17. The shaft 15 may be moved along by a hand lever 16 to position whichever of the cams 14 is required according to the tool-stroke desired. The speed of rotation of the shaft 15 may also be varied by belt pulleys 20, Fig. 2, or a two-speed toothed gear-drive 33 controlled by a hand-operated dog clutch 57. The spindle drive motor 23 is also used for driving the feed gearing. Bar-feed, stock stops.-A drum rotatably mounted above the machine on a vertical shaft 34, Fig. 3, is charged with stock bars in tubes 35. The drum is rotated stepwise by a weight 44 and ratchet mechanism coupled to the machine movement and a catch is released, when a bar is over a hollow machine spindle, to allow the bar to fall into place against a resilient stock stop 72, Fig. 1. A supplementary stock stop 87, Fig. 2, is used when the bars are required to be arrested with only a short piece extending from the chucks. Stop-motions.-If a tool 27, Fig. 2, encounters undue resistance to cutting the slide-actuating lever 8 compresses a spring 26 and a screw stop 54 engages a rod 28 which rocks a lever 29 and operates switchgear (not described) to stop the machine.