GB489240A - Improvements in or relating to work gripping and driving devices - Google Patents

Abstract

489,240. Chucks and mandrels. BRADLEY, W. Feb. 5, 1937, No. 3397. [Class 83 (iii)] A work gripping or driving device for imparting rotation or reciprocation or both movements to solid or hollow work-pieces comprises resilient rings which are expanded or contracted by axial pressure and which are mounted between driving washers or discs splined on or within the driving member. The rotary spindle H journalled and located axially in a bearing I by a nut G has a central opening of polygonal section to receive a similar rod A. One end of the rod is screwed to take a hand wheel B and the other end is provided with a head U, whilst an outer cap M is pinned thereto at N. Resilient rings R of rubber &c. are located within a work-piece T and further rings R<1> are located outside the work, washers Q, Q<1> being placed between the rings and splined to the rod A and cap M. Axial pressure on the rod A produced by rotating the hand wheel B and reacting on the spindle H through a spring C, washer D and sleeve F, compresses the rings against an abutment O acting on the spindle through pins L, thereby expanding rings R and contracting rings R<1> against the work to grip it internally and externally. The sleeve F is splined to the rod A, and a sprocket E through which the work is rotated engages the sleeve by a screw-thread and has axial clearance at W so that the driving torque, in either direction, can cause further axial movement of the rod A to increase the grip on the work. For gripping hollow work internally, the inner rings R only may be used, the cap M then being dispensed with and the end washer Q then abutting on a thrust collar which engages the spindle H, and for gripping solid work externally the outer rings only are used. Ball thrust bearings may be placed on each side of the sprocket E and the extent of the grip provided by the drive may be regulated by varying the pitch of the thread on the sleeve F and by varying the degree of friction of the sprocket on its end surfaces.