公开(公告)号：US3824026A

公开(公告)日：1974-07-16

申请号：US34238173

申请日：1973-03-19

Applicant: GASKINS T

Inventor： GASKINS T

IPC: B23B51/02

CPC classification number: B23B51/02 ,  B23B2251/18 ,  B23B2251/201 ,  Y10T408/898 ,  Y10T408/901 ,  Y10T408/909 ,  Y10T408/9097

Abstract: Improved drill bit lead end constructions which more particularly provide for sharp cutting lead or center point constructions to enhance the efficiency and effectiveness particularly of relative small diameter bits. The sharpened lead points include an axially disposed cutting edge which axially offsets a pair of inclined radial cutting edges which normally correspond to or are disposed upon the usual cone segment lips of a regular twist drill. One of the inclined radial cutting edges may be considered a hypotenuse relative to the axial cutting edge to thereby form a generally right triangular shape or profile to the lead end in some forms. Drill bits with these improved cutting lead ends provide at least a generally centering action while assuring essentially instantaneous cutting commencing from the initial contact of the drill bit with the material being drilled.

Abstract translation: 改进的钻头引线端构造，其更特别地提供锋利的切割引线或中心点结构，以增强特别是相对小直径位的效率和有效性。 锋利的引导点包括轴向设置的切割边缘，其轴向偏移一对倾斜的径向切割边缘，其通常对应于或者设置在常规麻花钻的通常的锥形部分边缘上。 一个倾斜的径向切割边缘可以被认为是相对于轴向切割边缘的斜边，从而以某种形式形成到引导端的大致正确的三角形形状或轮廓。 使用这些改进的切割引线端的钻头提供至少一般的定心作用，同时确保从钻头与被钻探材料的初始接触开始基本上瞬时切割。