GB548533A - Improvements in or relating to machines for drilling diamonds - Google Patents

Abstract

548,533. Drilling machines. GRODZINSKI, P. March 10, 1941, No. 3247. [Class 83 (iii)] A diamond drilling machine comprises an axially movable rotary spindle 10 carrying a needle 15 and a work spindle 3 rotating in the opposite direction to the tool, both spindles being driven by belt gearing arranged to avoid lateral strains on the spindles. A lower extension of the column 1 carries a bushing 4 coned internally to coact with corresponding cones on the work-spindle 3 which is feathered to an inturned flange on a driving pulley 9 mounted on a ballbearing 8. The needle spindle is journalled in two long bearing bushes 11, 12, which jointly form a bearing for a driving pulley 14 carrying a key engaging a long keyway on the spindle the bushes have taper portions engaging corresponding parts on the frame and are adjusted by nuts 13a, 13b. The pulleys are driven in opposite directions by a continuous belt 21 from a driving shaft 20, Fig. 5. The axial reciprocation of the tool is controlled by a collar 16 on the spindle coacting with a loose sleeve pivoted to a lever 25 operated through an adjustable connection 28 from a lever 23 actuated by a cam 19 driven from the shaft 20. The movement of lever 23 may be limited by a screw 27. In a modification the machine may be arranged horizontally, Fig. 6, the tool and work spindles being driven by open and crossed belts from a countershaft 29. In another modification the axial movement of the spindle may be produced by an intermittentlyacting solenoid.