Self boring rock bolt with expansion elements coupled to the drill head by a keyway and key

摘要

Disclosed is an self-drilling anchoring device or bolt for fastening in rock for mining. The anchoring bolt includes a drilling assembly including an elongate shaft with a drill head at one end, and another end configured to connect to a drilling apparatus; and at least one expansion element. The drill head and expansion element(s) are configured to cooperatively interlock with each other via a first engagement portion on the drill head cooperatively fitting with a second engagement portion on the expansion element to provide for directed movements of the drill head and expansion element(s) relative to a longitudinal axis of the shaft. Co-operating contact surfaces between the drill head and the expansion element(s) are configured such that relative longitudinal movement of the drill head with respect to the expansion element(s) displace(s) the expansion element(s) outwardly so the expansion element(s) can provide frictional contact with a borehole once inserted therein. The combination of first and second engagement portions form a dovetail arrangement.