GB712620A - Improvements in centreless work-holding attachments for lathes, grinding machines and similar machine tools - Google Patents

Abstract

712,620. Lathes; work-rests. SILBERSTEIN, V., and AIRCRAFT STEEL STRUCTURES, Ltd. May 26, 1952 [Feb. 26, 1951], No. 4658/51. Class 83 (3). [Also in Group XXIII] A centreless work-supporting and driving attachment for a lathe or grinding machine comprises a group of three rollers rotatably mounted at one end and so disposed that an end portion of a cylindrical rod can be held and rotated thereby, an axial thrust being exerted on the rod to feed it against an end-stop and maintain it there during operation of the tool. Two of the rollers 5, Fig. 1, are carried on spindles 4 in a block 1, Fig. 3, secured to a base 2. The axes of these rollers are parallel and the spindle ends opposite the rollers carry worm wheels 6 which engage a long worm 7 carried on a cross shaft 8 driven by a pulley 19 from a belt 20 and electric motor. The upper roller 12, Fig. 1, has its axis at a small angle to, but, in a plane parallel to, that of the other two and is preferably shaped to maintain line contact with the work. The third roller 12 is carried in an upper block 10, and is similarly driven by worm gearing and a pinion 16 meshing with a pinion 9 on the cross-shaft 8. These pinions have deeply meshing teeth to allow the upper roller 12 to be moved a limited amount away from the other rollers for insertion of the work parallel to spindles 4, a spring, 25 forcing the block 10 and hence the roller 12 downwardly when a lever 17 is released. An adjustable stop 22 is provided to limit the distance through which the workpiece may be inserted between the rollers.