Rotary drill bit and roller cutter for rock drilling
AssigneeSandvik AB
InventorLennart Karlsson
Life of this patent
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Abstract
A rotary rock drill bit includes a bit body and three conical roller cutters rotatably mounted thereon. Each roller cutter has at least first, second, and third circumferential rows of buttons spaced apart in the direction of rotation of the roller cutter. The three rows of buttons are arranged successively from a rear end toward a front end of the roller cutter. The buttons of each of the first and second rows have lengths of attack which are longer in a direction of rotation of the roller cutter than in a direction perpendicular thereto. Those longer lengths of attack are also longer than a length of attack of the buttons of the third row in the rotational direction.
Claims10
Rotary drill bit for the rotary crushing drilling of rock, said bit comprising a bit body and three roller cutters, each roller cutter being rotatably mounted on a journal protruding from the bit body, each roller cutter including a roller body having a generally conical shape with a rear end facing generally towards the periphery of the drill bit and a front end facing generally towards a rotational center of the drill bit, wherein a number of rock-crushing buttons are provided in each roller body to form at least first, second and third circumferential rows of buttons, the first, second and third rows of buttons being arranged successively from the rear end toward the front end of the roller cutter, each button having a working end which projects from the roller body and which during rotation of the roller cutter comes into engagement with the rock, wherein each button of the first and second rows having a length of attack which is longer in a direction of rotation of the roller cutter than in a direction perpendicular thereto, the buttons of the third row having a length of attack in the rotational direction which is shorter than the lengths of attack of the buttons of the first and second rows in the rotational direction.
A roller cutter for use in a rotary rock drill bit, the roller cutter including a roller body defining an axis of rotation and having a generally conical shape with a large rear end and a smaller front end, a number of rock-crushing buttons mounted in the roller body to form at least first, second, and third circumferential rows of buttons, the first, second, and third rows of buttons being arranged successively from the rear end toward the front end of the roller cutter, each button having a working end projecting from the roller body for engaging rock during rotation of the cutter body, wherein the button of each of the first and second rows having a length of attack which is longer in a direction of rotation of the roller cutter than in a direction perpendicular thereto, the buttons of the third row having a length of attack in the rotational direction which is shorter than the lengths of attack of the buttons of the first and second rows in the rotational direction.
Dependencies are inferred from the claim text.