| 摘要 |
1,134,719. Deep-hole drills. F. E. SANBORN. 15 April, 1966, No. 16749/66. Heading B3C. A deep hole drill comprises a round section rod 10, Fig. 1, having a round shank portion 11, an intermediate portion 13 of semicircular crosssection, and a cutting end portion 12 of circular cross-section having a quarter section removed. Portion 12, has a wall 17 which is arranged at an angle to the axis of the drill, Fig. 2, and connects the cutting edge 19 with a point 18 on the drill periphery. Wall 17 may form a right, acute, -or obtuse angle with surface 16, in cross section and may be flat or convex. The edge 19 extends radially for at least the radius of the drill, Fig. 9, and the drill may provide a peripheral clearance from point 23 to point 24. End 12 may be flat or conical, and cutting edge 19 may have a positive, zero, or negative rake. |
