GB873741A - Drill pointer - Google Patents

Abstract

873,741. Drills; chucks. WINSLOW PRODUCT ENGINEERING CORPORATION. May 18, 1960 [May 25, 1959], No. 17519/60. Class 83 (3). [Also in Group XXIII] A drill is sharpened in a grinding machine, (Group XXIII), by mounting it in a holder 38 comprising a sleeve 102 housing both a removable bushing 108 for supporting the drill near its tip and a chuck 114 having jaws 130 for clamping the drill in position. The chuck is rotatable from an hydraulic motor through worm teeth 170 on its periphery meshing with a worm gear 172 on a vertical shaft 200 disposed within a tubular post 90 on which the holder is secured so that it can reciprocate and oscillate with the latter. The jaws 130 move in radial slots 120 in the chuck body and are urged to clamping position by an internally-flared sleeve 134 which acts through balls 124 and plungers 126 on the jaws when it is moved axially against springs 136 by pressure fluid operating against an annular piston 156 in a cylinder 154. At the end of one grinding operation and start of the next, the drill holder is at rest in an extreme upper position in which it is angularly positioned so as to be in alignment with a sleeve 448 constructed both for ejecting a finished drill and locating a new drill in position. The sleeve houses an ejector rod 456 operable by a fluidactuated cylinder-and-piston device and is constructed so as to receive a new drill as it is inserted in the chuck and, when the tip of the drill is forced manually against its end, rotates the drill to a predetermined angular position in the chuck. The resulting drill tip has a pronounced point P, Fig. 13, with concave reliefs R, Fig. 12.