Patent GB-760299-A (GB)
Title: Improvements in or relating to chuck arbors
IPC: B23B31/02
Filed: 1954-11-04
Abstract: 760,299. Mandrels. WOODWORTH CO., N. A. Nov. 4, 1954 [Nov. 5, 1953], No. 31943/54. Class 83 (3). A work-holding mandrel for internallysplined work comprises axially-spaced members 20, 22, Fig. 1, with splined portions 30, 32 for work 34, resilient torsion means coupling the members together with the splines either in or out of alignment, one member being capable of being turned relatively to the other to misalign or align the splines to grip or receive the work respectively, the resilient means restoring the members, when released, to their normal positions. The means consists of a shaft 24 with an axial-bore 42 and slotted longitudinally to provide four or more radial ribs 46 in its central region of enlarged diameter. The smaller end regions 52, 54 have slots for pins 26, 28, which secure members 20, 22 to the shaft. The ends 60, 62 of the members are shaped, e.g. hexagonal, to receive spanners for aligning the splines, and are recessed as at 72, 74 for mounting between centres 68, 70. A pin 64 protruding from member 22 engages a slot 66 in member 20 thereby to limit the amount of relative turning between the members. Members of varying diameters may be provided for selective mounting on a common shaft 24 to cater for work of different sizes. In another arrangement the torsion means is separate from the shaft and consists of rods equally spaced apart and engaging bores in the members, a locating collar for the work extending from a flange on one member. In another arrangement the members are interconnected by axial ribs adjacent the periphery, which ribs constitute the torsion means. In a modification, the members 180, 182, Fig. 14, are interconnected by bars or ribs 188 with their splines in alignment. The ribs extend obliquely to the mandrel-axis and cause relative turning of the members as they are moved towards one another. This movement is incurred by a bolt 192 having its head 196 locked by pin 198 to member 180 and extending through bore 194 in the members to engage a nut 204 and washer 202 bearing against the end of member 182. Thus, tightening of the nut moves the splines out of alignment to grip the work. A work-locating collar 208 is provided and a shoulder 206 on the bolt limits the extent to which the nut may be tightened. In another arrangement, member 130, Fig. 11, having splines 134, has a bore 138 receiving a cylindrical extension 146 of member 132 which has splines 136. The splined portions are spaced apart by a sealing-ring 148, and a lubricantreservoir 142 for the extension is formed by reduced-part 140 thereof. The extension has a part 154 formed by removing segments from each side thereof, the part constituting the torsion means and being succeeded by a threaded part 156 engaging threaded part 158 of bore 138 and being locked by a counterscrew 162. Turning of member 132 to align the splines is resisted by part 154, which subsequently urges members 130, 132 to grip the work. Work-locating collar 166 is provided, and for securing closed-end work, member 132 may terminate flush with the splines 136, turning thereof relatively to member 130 being effected by gripping the work. Alternatively, means may be affixed to part 154 and extend outwardly through a slot in member 130.