GB1200116A - Drill grinding machine - Google Patents

Abstract

1,200,116. Grinding drills. MICRON ETABS. 20 Nov., 1967 [28 Nov., 1966], No. 52609/67. Heading B3D. A drill grinding machine comprises a grinding wheel 3, a drill holder 9 arranged on a frame 1 so that the drill can be moved opposite the grinding wheel, a support part 22 for engaging the end of the drill to prevent deformation and vibration of the drill during grinding, a mount 7a on which the support part is mounted in a movable manner so as to engage the drill when the latter is in its initial grinding position, and an electrical warning device of which the supply circuit passes through the drill and support part so that the device functions when the support part contacts the drill to signal to an operator that the contact is released in order to avoid the operator straining or breaking the drill by untimely continuation of the approach movement of the support part. The grinding wheel is bell-shaped and mounted in the frame which has a transverse slide 4 on its front face, the slide supporting a carriage 5 for moving a drill 10 mounted in a holder 9 on the carriage between a stop plate 12 and the operative surface 11 of the grinding wheel. The holder 9 is carried by a sleeve 15 indexable in a sleeve 8a, the holder also being axially adjustable by a micrometer screw to bring the point of the drill into engagement with the stop plate. The sleeve 8a is carried by a support 8 extending from a sleeve 7a mounted by an arm 7 on the carriage 5. The support part 22 is carried in the sleeve 7a by insulating bushes 20, 21. The holder 9 and arm 8 are rotable about the axis of the sleeve to adjust the cutting and clearance faces of the drill to the plane of the stop 12 and grinding plane 11. The part 22 is rotatable by a pin and slot 25, 26 with the arm 8. The end of the part 22 is formed with a concave part and V-groove 32 to receive the end of the drill, the opposite end of the part being formed as an electrical connector 22a. In operation, the drill is mounted in the holder 9 which is adjusted to engage the drill point with the stop 12. The support part 22 is then advanced by a micrometer screw 23, 24 until it contacts the drill and completes the circuit of a warning light 35. Thereafter, the carriage 5 is moved to engage the drill with the grinding wheel while the drill is supported by the part 22. In addition, a light 36 may be operated when the drill is initially adjusted to engage the stop 12. The arm 7 is adjustably secured to the carriage 5 by a bolt 6 the axis of which is in the plane of the grinding wheel.