GB386435A - Improvements in or relating to mandrels for use in machining and other operations - Google Patents

Abstract

386,435. Mandrels. LOCKHEED HYDRAULIC BRAKE CO., Ltd. and SHERWOOD, W. J., Brock House, Langham Street, London. Jan. 8, 1932, No. 616. [Class 83 (iii).] A mandrel for cylindrical and tapered work-pieces of the type comprising a number of rollers held in spaced relation in recesses around the periphery of a bar, the rollers being arranged to grip the work upon relative movement of the latter with respect to the mandrel, is provided with springs which tend to move the rollers to the deepest parts of their grooves. A rod 12, one end 11 of which is adapted to fit a lathe or like machine, has recesses 13 which decrease in depth in a clockwise direction, Fig. 3, so that rollers 16 carried therein are forced outwards when rotated across the recesses ; springs 23, 25 normally keep the rollers in the deepest part of a recess, and inserts 21 and an end-piece 26 embrace the reduced roller ends 19, 20 to suitably restrict their movement. A work-piece, of interior diameter sufficient just to slip over the rollers in their neutral position when rotated in a clockwise direction relative to the mandrel, is gripped by the rollers with increasing intensity. The base of the recess may be normal to the radius of the rod so that the rollers are innermost in a central position, Fig. 5, and a modification consists in arranging the rollers in a rotatable cage the ; mandrel may also be adapted to work between centres.