GB332307A - Improvements in or relating to lathes for cutting-off bar-stock - Google Patents

Abstract

332,307. Jacobowitz, A., and Mars-Werke Akt.-Ges. April 26, 1929. Latches; steady-rest.-a cutting-off lathe, particularly for producing roller-pins from barstock, the stock is fed by known means against a gauging-stop, a blank is severed by a high-speed friction saw and the edge of one blank and the adjacent edge of the succeeding blank are bevelled by a turning-tool. The blank is supported over the greater part of its length during cutting by means of a sleeve surrounding the gauging-stop. The lathe comprises a bed 1 supporting an electric motor 3 which rotates the friction saw 4 and also drives the actuating cams by means of a belt 5, Fig 3, and shafts 18, 16. A saddle 7, Figs. 2 and 3, slidable transversely on ways 6 on the bed, supports a supplementary slide. 8 carrying the bevelling-cutter 10 on a longitudinal slide. The hollow-spindle. 30 which receives the barstock 41 is rotatable by means of spur gears 26 - - 28, bevel gears 25 and the shaft 18 and is mounted in a casing 29 supported on the saddle 7. A chuck 30<1> on the spindle is operated by levers 31 and a cone 32 under the control of a lever 33 and a cam 21 on a shaft driven bv a bevel gearing 20 from the shaft 18. The saddle 7 is actuated by a cam 15 on the shaft 16 and the tool slide 8 by an adjustable lever 23 and a cam 22. In operation, the stock is fed against the gauging-stop 37, Figs. 3 and 5, and the chuck is then closed. The saddle 7 is next traversed towards the saw 4 to sever a blank, carrying with it the stop 37 and causing a roller on a lever 36 pivoted to the saddle to engage a fixed cam slot 12. thereby rocking the lever and moving a sleeve 35, surrounding the stop 37, over the end of the work to support it during cutting as shown in Fig. 7. When a blank has been partially severed a dwell on the cam 15 allows the saddle, to remain stationary or recede slightly whilst the cam 22 feeds forward the slide 8 to enable the tool 10 to bevel both sides of the groove cut by the saw, as shown in Fig. 7. The slide 8 is then retracted by a spring 8<1> and the saddle is advanced to complete the severance. On the return motion of the saddle the lever 36 withdraws the sleeve 35 and allows the stop 37 to eject the severed blank. During the advance of the saddle the rear end of the stop 37 is pressed by a spring 37<1> into contact with a stop 39 adjustably mounted on a bracket 38 fixed to the bed 1 to enable accurate gauging of the stock to be accomplished. The outer end of the stock is supported by a bracket 40 on the saddle and the roller of the lever 33 is disengageable from its cam to allow the chuck to be opened by hand for setting the machine or introducing new stock. In an alternative construction the saddle 7 and the work remain stationary while the motor and saw are fed to sever a blank, the tool-slide. 8 and the sleeve 35 then being operated by the movement of the saw carriage. In order to ensure the cut-off end of the blank having a smooth surface the setting stop 39, Fig. 10. has an oblique face, d so that as the saddle 7 advances during cutting from a to b, the gauging stop 37 may be retracted by its spring through a distance c and so relieve the end of the work from axial thrust during severance. On the return of the saddle the face d restores the stop 37 to its position for gauging the feed of the stock 41.