Improvements in the Construction of Die Heads or Die Holders and Chasers or Dies of Screwing Machines, and in the Attachment and Fitting of the said Chaser or Dies to such Heads or Holders

摘要

1279. Wharton, H. Jan. 19. Screwing.-A self-opening die head for a screwing-machine has shank c, on which is rather freely fitted a head a having bowls a10 sliding in slots c3 in the shank so that the head rotates With the shank. Levers e, pivoted at e3 in the head, engage at their ends e5 with slides d, moving radially on the face of the head and carrying chasers h, set up by coned screws i and clamped by coverplates m secured to the slides. The bead is normally drawn back against a collar c5 on the shank by springs g, and in this position bowls e4 on the levers e ride on the collar, holding the dies in the closed position. When a sufficient length of the work has been screwed, the head is drawn forward independently of the shank, the howls e4 leaving the collar and being drawn inwards by springs (not shown) connecting the rear ends of the levers, opening the dies and releasing the work. A bandle and hooked levers (not shown) are provided to press the slides d in wards, allowing the head to be drawn back by the springs g to reset the dies.