Improvements in drilling devices

摘要

599,469. Drilling; drills. ANDREASSON, R. W. Sept. 18, 1945, No. 24060. [Class 83 (iii)] Oil is supplied under pressure to recesses in the lands of a fluted drill by a device comprising a body member having a close-fitting bore in which the drill can slide, oil passages communicating with the recesses in the lands, but sealed from the flutes, and means for preventing rotation of the body member with respect to the drill. As applied to a rotating drill 22, Fig. 3, having spiral flutes 26 and recesses 30 in the lands, the body member 34 has a bore 36 and, to ensure its rotation with the drill, a cap 44 secured by screws to the body has a bore with projections 52, Fig. 5, which engage the recesses 30, as shown, or the flutes or both. The cap also has ears 48 engaging slots 42 arranged in the body member in alignment with the helix of the recesses 30. A sleeve 64, to which an oil supply pipe 76 is connected, is rotatably fitted on the body member and forms an oil chamber sealed by washers 68, 70 and communicating with the recesses 30 through holes 62 in the ears 48. Leather sealing strips 82 secured to the cap 44 are fitted to prevent oil flowing upwards towards the drill shank. To permit the discharge of cuttings and oil flowing upwards from the drill point, radial slots 86 are cut in the body member in alignment with the flutes the slots act as a centrifugal pump aiding the withdrawal of cuttings and oil. The device may be pressed against the work by a spring 60. In a modification, Fig. 10, the recesses 30<11> are of semicircular form, the communicating holes 62<11> from the oil chamber are drilled in the body member and the sealing means comprises balls 102 in holes 100 slightly restricted at the inner ends so that the balls can project sufficiently to seat in the recesses 30<11> under the oil pressure acting through apertured plugs 104 ; the cap 44", which has no ears, has projections modified to fit the semicircular recesses. As applied to rotating work, Fig. 8, the sleeve 64 is omitted and fluid is supplied through branch pipes 94 connected to a flexible tube 98 that permits a small amount of rotation of the body as the drill is fed into the work. When. the device is used as a drill bush by setting it in a jig, roller bearings may be fitted between the sleeve 64 and body 34.