Patent ID: 6113477
Filing Date: 2000-09-05
Classification: B24B

Abstract:
A drill abrasive apparatus which is capable of grinding a candle-shaped drill requiring Z-type thinning, characterized by comprising a whetstone (1), a drill holder (5), a drill adjustable pedestal (2), a drill abrasive pedestal (3) and a drill thinning pedestal (4), wherein an abrasive surface of said whetstone is composed of a parallel surface (11) formed parallel with a rotating axis of said whetstone, a relief surface (12) for a chisel portion at a central portion of the drill formed in front of said parallel surface, a slanted surface (13) for a thinning process formed behind said parallel surface so as to have a predetermined angle, and a second parallel surface (14) formed behind said slanted surface so as to be parallel with the rotating axis of said whetstone, said drill holder is composed of a cylindrical drill insertion portion (51), and a holder ring (52) which has a guide groove (52e) for regulating a rotating angle of said drill holder and is mounted to one end of the drill insertion portion so as to have a cutting edge-shape, said drill adjustable pedestal is composed of a fitting hole (21a) into which the drill insertion portion can be fitted, an adjustable base pedestal (21) having a latch projection for determining an angle and position of said drill holder, and a stopper (22) which is mounted on a forward side of the fitting hole so as to be integral with the adjustable base pedestal, said drill abrasive pedestal is composed of a fitting hole (31) into which the drill insertion portion can be fitted and when the drill insertion portion is inserted into the fitting hole until the holder ring of said drill holder comes in contact with a peripheral edge portion of the fitting hole, the cutting edge of the drill comes in contact with the abrasive surface of said whetstone and a latch projection (31a), which is inserted into the guide groove with a play existing therebetween, is provided on the peripheral edge portion, said drill thinning pedestal is composed of a fixing leg (41) fixed to a base (8) and a fitting portion (42) which is mounted to the fixing leg and has a fitting hole (42a) into which the drill insertion portion can be fitted, said fitting portion has a latch projection for determining the angle and position of said drill holder and can be slanted towards said whetstone within a predetermined angle range.