| 摘要 |
A drilling tool with rotating conical rollers, such as a bicone, a tricone, etc. wherein each roller is fitted with several circular rows of teeth 22 made of tungsten carbide or the like. Each tooth has at its end, successively in the direction where it rolls on the rock, a rear or impact zone 24, a central zone 28 with a rounded shape, and a forward zone 30 which is last to come into contact with the rock. The teeth are fitted with diamond-charged elements 32, 34 on the forward zone and optionally on the central zone, but not on the rear zone.
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