GB541777A - Improvements in lathes for turning shells and the like - Google Patents

Abstract

541,777. Turning projectiles. HEPBURN, J. T. Feb. 23, 1940, No. 3473. [Class 83 (iii)] A lathe for turning shells &c. has a driver operated by pneumatic means for gripping the inner bore of the shell and a tailstock also operated by pneumatic means to engage the work before actuation of the driver. The bed carries a headstock 22 whose spindle is fitted with a driver having jaws 25 which are expanded by means of a pneumatic cylinder 27. The tailstock 31 has a spindle 32 which is engaged with the work by a pneumatic cylinder 34. A saddle 36 longitudinally movable on the bed carries a transversely movable tool holder 37 operating as described in Specification 541,801. In operation, after positioning the shell over the driver a foot valve 76 is depressed to admit air to lines 78, 79. A retarding valve 74 is placed in line 78 so that the tailstock spindle 32 is moved up before the cylinder 27 actuates the driver. A switch 80 is then pressed to start the spindle driving mechanism (not shown). At the end of the operation valve 76 is actuated to admit pressure to lines 99, 100 and withdraw the tailstock and disengage the driver. A switch 17 is actuated to stop the shell rotation before the work is released. Specifications 541,799 and 541,800 also are referred to.