Patent GB-891244-A (GB)
Title: Improvements in or relating to grinding devices
IPC: B24B41/06
Filed: 1959-12-17
Abstract: 891,244. Grinding drills. WURM-RElTH-MEYER, A. Dec. 17, 1959 [Dec. 24, 1958], No. 42943/59. Class 60. Apparatus for grinding the cutting edges of drills having cylindrical shanks comprises a clamping ledge with slots arranged side by side, the inclination of the slots to the longitudinal extent of the clamping ledge corresponding to the cutting angle of the drill, and a grinding device which covers the width of all the slots. This enables a batch of drills to be ground simultaneously. A base plate 1 has guide rails 2, 3, 3, stops 4, 5, a brake spring 6, and a clamping ledge 7 provided with slots running obliquely. A grinding device 10 covers the width of all the slots. Accurate alignment of the cutting edges of the drills 9 to be ground is effected by members 11 engaging in the flutes of the drills: The drills are held in the slots by a pivoted clamp 12 closed, against a spring 21, by cam plates 19 on a spindle operated by a handle 17. A gripping device has a base member 21 the front end of which carries a fixed vice part 22 comprising a front bar 26 with slots similar to those in the clamping ledge 7 and a rear stop bar 27 with oblique stops corresponding to the inclination of the slots. A pivoted vice part 25 has a projection 29. A pivoted lever 31 co-operates with a screw 33 carried by the part 25 and has a roller 37 co-operating with a tapered member 35 on a rod 34 moved axially by a handle 36. The part 25 is urged to open position by a spring 38. The base member 21 carries adjustable stop rods 38a, 38a, which co-operate with the stops 4, 5 on the base plate 1 when the base member 21 is mounted on the guide rails 2, 3, 3 of the base plate 1. A magazine comprising a base plate 41, side walls 43, 43 and longitudinal walls 44, 44 is loaded with drills 9. Displacement of a thrust plate 46 pushes a batch of drills on to a ramp 40. The gripper device is then pushed up so that the ends of the drills opposite to the ends which are to be ground are engaged by the vice part 22, whereupon the rod 34 is pulled out to operate the vice part 25 so that the drills are gripped and their front ends lifted from the ramp 40. The gripper device thus charged with drills is pushed on the guides 2, 3, 3 of the base plate 1 so that the drills lie over the slots in the clamping ledge 7. The rod 34 is then pushed in to open the vice. The gripping device is then advanced, the guide members 11 engaging sooner or later in the flutes of the drills so that at the end of the forward movement the cutting edges to be ground are in alignment. The drills are then clamped in ledge 7 by operating the handle 17 and grinding effected by relative traverse of the base plate 1 and grinding device 10. The drills are then unclamped, the vice 22, 25 closed and the gripping device pulled back. The vice 22, 25 is opened and the gripping device pushed forward, the guide members 11 causing rotation of the drills through 180 degrees from their previous positions. The drills are again clamped in ledge 7 and grinding effected. Modifications of the details of construction are described.