| 摘要 |
<p>An elongate cutter 14 for a drag-type drill bit includes a stud defining one end thereof and a cutting formation comprising a cutting face 16 generally adjacent the other end. Length extends from one end to the other, depth extends generally transverse to the cutting face 16, as well as transverse to the length, and width extends transverse to both length and depth. The stud has a cross section transverse to its length such that the cross section cannot be circumscribed by a reference circle C1 whose diameter is equal to the maximum width of the cross section. The cross section also has an assumed section modulus, in the direction of depth, greater than that of the reference circle. The leading side of the cutter 14 may comprise a first planar zone adjacent the one end and a second planar zone adjacent the other end, and on which the cutting formation is carried. The maximum lateral dimension of the leading side is generally greater than or equal to the maximum width of the cutter.</p> |
