Methods of attaching a shank to a body of an earth-boring tool including a load-bearing joint and tools formed by such methods

摘要

Earth-boring rotary drill bits may include a bit body attached to a shank assembly at a joint. The joint may be configured to carry at least a portion of any tensile longitudinal and rotational load applied to the drill bit by mechanical interference at the joint. The joint may be configured to carry a selected portion of any tensile longitudinal load applied to the drill bit. Methods for attaching a shank assembly to a bit body of an earth-boring rotary drill bit include configuring a joint to carry at least a portion of any tensile longitudinal and rotational load applied to the drill bit by mechanical interference. The joint may be configured to carry a selected portion of any tensile longitudinal load applied to the drill bit by mechanical interference.

主权项

1. An earth-boring rotary drill bit comprising:
a bit body comprising a first connection portion; a shank assembly comprising a second connection portion, the shank assembly comprising two or more separate members located at different radial positions around the first connection portion, the two or more separate members being secured together around the first connection portion; and an intermediate material interposed between the bit body and the shank at a threadless joint, the threadless joint configured to carry at least a portion of any tensile longitudinal load applied to the earth-boring rotary drill bit by mechanical interference between the bit body and the shank assembly at the threadless joint, wherein at least one surface of the first connection portion is oriented at a first acute angle with respect to a longitudinal axis of the bit body and at least one surface of the second connection portion is oriented at a second acute angle with respect to the longitudinal axis of the bit body, the first acute angle and the second acute angle being less than or equal to the arc-cotangent of a static coefficient of friction exhibited between the at least one surface of the first connection portion and the at least one surface of the second connection portion.