Drill rod and drilling apparatus

摘要

A drill rod assembly for use in rotary drilling in a mine roof includes a plurality of releasably engageable drill rod members connected in end to end relation. One end of the assembly receives a cutting bit and the opposite end is drivingly connected to a drill chuck of a drill head. Each drill rod member includes a shank end portion, a socket end portion and a body portion extending between the shank end portion and the socket end portion. The shank end portion of each drill rod member is releasably engageable in the socket end portion of an adjacent drill rod member. The length of the drill rod assembly is progressively expanded to the length required for drilling a bore hole of a preselected depth into a mine roof. The shank end portion of each drill rod member is twisted in a helical pattern forming a plurality of helical faces around the axis of the shank end portion. The socket end portion of each drill rod member has an internal bore formed by a plurality of helical faces. The helical faces of the socket end portion have a lead that corresponds to the lead of the helical faces on the shank end portion. The shank end portion of a drill rod member is insertably received in the socket end portion of an adjacent drill rod member where the respective helical faces are positioned in abutting parallel relation. The application of torque to the drill rod assembly urges the abutting helical faces of the connected drill rod members into increasing frictional engagement to prevent separation of the connected drill rod members as the drill rod assembly is retrieved from the drilled bore hole.