Patent ID: 6196908
Filing Date: 2001-03-06
Classification: B24D,Y10T

Abstract:
A drill for drilling a hole in a composite material, the drill comprising:a shank; anda pair of prongs diametrically opposed from one another and extending axially from the shank, each of the prongs having a tip for initiating the hole, each of the prongs further having a grinder disposed axially adjacent to the tip for grinding the hole, each of the grinders having a tapered cylindrical surface axially tapering toward the tip and grinding means on the tapered cylindrical surface, each of the prongs further having a reamer disposed axially between the grinder and the shank for finishing the hole, each of the reamers having a constant diameter cylindrical surface and reaming means on the constant diameter cylindrical surface, wherein each of the prongs further have a tapered cylindrical transition step disposed between the tapered cylindrical surface of the grinder and the constant diameter cylindrical surface of the reamer for providing a step less change between the grinding means and the reaming means.