GB567966A - Improvements in the method of, and apparatus for, forming the recess in the base of shells or like products - Google Patents

Abstract

567,966. Turning projectiles. HEPBURN, J. T. Jan. 5, 1939, No. 457. [Class 83 (iii)] For turning a recess in the base of a shell or the like, a tool with a cutting portion of width substantially equal to the radius of the recess is fed axially against the work to cut the recess. Four tools 29-32, Fig. 1, are provided on a cross-slide 35 of a lathe, the first two rough. turn the recess and outside of the base, while the second two perform the corresponding finishing operations, their operative positions being determined by the stops 20A and 20 respectively. The rough-recessing tool 29 is set in position by placing a finished shell in the chuck 14 and bringing the adjustable stop 21 against a pivoted gauge block 24, Fig. 2, which is previously swung over into the path of the stop 21 ; the tool is then clamped in a position where it just contacts the base of the shell. The tool slide is next moved across until it contacts the stop 20A, and the finish-recessing tool 31 set in a similar manner. The gauge block 24 is of a thickness equal to the required rough depth of the recess and when swung aside allows the tool 29 to cut the recess, the movement being limited by the stop 21 engaging the face 26 of the gauging device 27. The latter is then rotated slightly to move the stop piece 26 away from the gauge 21 an amount equal to the finishing cut, and the tool 31 moved into position to effect this cut. The tool 31 is also provided with a longitudinal cutting edge and after completing its axial movement it is moved slightly in a lateral direction to finish the walls of the recess. The tools 30 and 32 rough turn and finish, respectively, the base and riveting rib on the end of the shell during the roughing and finishing operations performed by the recessing tools.