| 摘要 |
883,821. Screw-cutting; tool-holders. HOLZER, C., and BUSHE, M. VON, [trading as KIESERLING & ALBRECHT, TH.]. July 3, 1959 [Aug. 19, 1958], No. 23009/59. Class 83 (3). A method and apparatus for cutting serewthreads comprises the use of a tool-holder carrying a number of cutting elements which are brought successively into the cutting position by automatic means. The cutting tool is provided with three cutting faces 3a, 3b, 3c, Fig. 6, and mounted in a holder 2 rotatable in a casing head 1, Fig. 1. The end of the holder is splined in a sleeve 10 which carries a ratchet wheel 14, Fig. 2, for indexing the holder, by means of a pawl 13, through steps of 120 degrees. The pawl is carried on a sleeve 9 moved by a rack 8 forming part of a piston 7 in a cylinder 5. The lower part of the rack carries a cam strip 8a which operates a rack plunger 17 engaging a pinion 20. Rotation of the latter is transmitted to a locking plunger 24, Fig. 1, which thus releases the holder prior to indexing. A further spring- pressed plunger 25 locks the holder against rotation opposite to the indexing movement. |
