GB1193415A - Drill Point Grinding Machines - Google Patents

Abstract

1,193,415. Grinding drills. Z. BRIERLEY Ltd. 25 Jan., 1969, No. 4337/69. Heading B3D. A drill point grinding machine comprises a motor-driven grinding wheel 11 and a workhead including a main housing 16 pivotally arranged on a support 14 and carrying a chuck 20 for a drill to be ground, the housing embodying a mechanism 21 which effects rotation of the chuck, axial reciprocation of the chuck, and swivelling of the housing, the axial reciprocation being effected by pivotal movement of a push bar 26 which extends chordally relative to a thrust ring 32 rotatably arranged on the spindle 18 of the chuck and engages a stylus 40 carried by the ring for ransmitting thrust from the push bar to the thrust ring. The support 14 can be adjusted about a pivot 15 along an aromatic track 13 and locked in position according to the taper to be ground on the drill's point. The main housing swivels relative to the support 14 also about the pivot 15 upon actuation of the mechanism 21 by a handle 22, the mechanism also rotating and axially reciprocating the chuck. The reciprocation is effected by rotation of a face cam 25 which is engaged by a follower 29 on one end of the push-bar 26 which has its other end mounted on a pivot 30 adjacent a bearing 17 for the spindle 18 of the chuck 20. The thrust ring 32 is rotatably adjustable on the spindle and bears by way of a thrust bearing against an end disc 19 on the spindle. The stylus 40 is located without a hole in the thrust ring and bears against the push bar so that as the face cam is rotated, the rocking of the bar 26 is imparted by the stylus to the thrust ring and, hence, the chuck. The amplitude of the reciprocation of the chucks is varied by rotating the ring 32 to positions determined by engagement of a spring-pressed plunger 35 with one or other of detents 38 formed in the ring to vary the distance between the stylus and pivot 30.