| 摘要 |
<p>A drilling and/or coring tool intended for use particularly oil drilling and/or coring, comprising a body (2) with a substantially cylindrical peripheral surface (3) and an underside (4), as well as blades (5) extending from the underside (4) to the peripheral surface (3). Each of the blades has a leading edge (6) and, if applicable, cutting elements of PDC (7) located in at least one central area (15A) of the underside (4). The longitudinal axes of these elements are disposed at right angles to the rotation axis of the tool (1). Outside of the central area (15A) are situated the following: cutting elements that are secondary and/or made of PDC (10), each with a cutting-edge (8) and which together form the leading edge (6) of the blade (5). The longitudinal axis of these elements is at right angles to the rotation axis. At least one associated cutting element (10A) is located to the reat of at least one of the secondary and/or PDC cutting elements (10) and has a transversal portion of the same shape as that of the secondary or PDC cutting element (10), at least for the portion projecting over the blade (5). The associated cutting element (10) is disposed on the same blade (5).</p> |
