GB847682A - Lathe chucks - Google Patents

Abstract

847,682. Chucks. WICKMAN Ltd. Nov. 3, 1958 [Nov. 15, 1957], No. 35741/57. Class 83 (3). A lathe-chuck for gripping a hollow workpiece comprises a body for securing to the lathespindle, a hollow nosepiece extending through the body and carrying a pair of oppositelydisposed jaws at its forward end which are actuated by an axially-slidable spindle, and a second pair of jaws at right-angles to the first jaws actuated by an axially-slidable sleeve on the spindle. A body 10, Fig. 1, is secured to a lathe spindle 11 and carries a hollow nose-piece 12 having jaws 15 mounted in guides 14 and actuated by a spindle 18. Jaws 17, Fig. 2, move radially in grooves 16 and are actuated by a sleeve 21. The work 13 is placed on the jaws, and the spindle 18 is moved to the right until a collar 26 contacts a collar 23, and further movement compresses a spring 24 which moves the sleeve 21, thus expanding the jaws 17 to grip the rear end of the work. Continued movement of the spindle 18 expands the jaws 15 to grip the forward end of the work. By this means the greatest gripping-force is exerted on the strongest part of the work by the jaws 15, as the force exerted by the jaws 17 is governed by the rate of the spring 24. In a modification, the sleeve 21 may be actuated by separate means, such means being co-ordinated with the movements of the spindle 18 to ensure that the jaws 17 grip the work before the jaws 15. A chuck is described wherein the jaws are secured to resilient cantilever arms attached to the body, and are sprung into and out of engagement with the work by a spindle and sleeve, as described above. Specification 145,814 is referred to.