GB966844A - Fixture for holding workpieces - Google Patents

Abstract

966,844. Grinding. BARNES DRILL CO. July 17, 1963 [July 18, 1962], No. 28312/63. Heading B3D. A- fixture for holding a plurality of workpieces 11, Fig. 4, such as connecting rods each having a bore 12 to be honed, with the bores in alignment and axially spaced by a predetermined distance comprises a locator having an elongated member 43, Fig. 8, comprising annular parts 45 carried thereby and axially spaced along the member by the predetermined distance so that one part is disposed within each bore, the annular parts being radially expandible against the wall of the associated bore to centre the bores about the elongated member. The annular parts 45 are in the form of sleeves which have split skirts 44 at their lower ends and cam surfaces 64 at their upper ends and are disposed on the member 43 which is in the form of a sleeve having an upper cap 47. The sleeve acts as a movable cylinder on a piston 48 and fluid pressure can be supplied above or below the piston to move the sleeve from a lower inoperative position to the position shown in Fig. 4 wherein each annular part 45 is disposed with its skirt within a bore 12 of a workpiece, which may be a connecting rod. The cap 47 is chamfered at its upper end to assist its passage through the bores and is received in a bush 47 in an arm 37 projecting from a honing machine. The upper sleeve is also chamfered to engage a tapered portion of the sleeve 42 and as the tube 43 is urged upwardly by the fluid pressure, the skirts 44 are expanded to engage the bore and align the workpieces which are disposed between fixed clamping members 22 and annular members 21 movable by fluid pressure supplied from a pipe 32 to hold the workpieces in their aligned positions. The elongated member and annular parts 45 can then be retracted from the bores and the clamping member swung about an axis a by a fluid pressure motor 38 having a piston rod 39 formed with a rack engaging a pinion 40 on a shaft 34 journalled in the table 20 of the machine, the swinging movement positioning the clamped workpieces in alignment with the axis b of the honing tool of the machine and positioning previously-honed workpieces in line with the elongated member so that they can be unloaded and replaced with new workpieces which are then aligned and clamped while the previously aligned and clamped workpieces are being honed. When the elongated member is engaged in the bores of the workpieces, a device 61 prevents rotation of the clamping members about the axis a. Specification 966,845 is referred to.