Abstract: A hydraulic system for moving a drilling head in a rectilinear motion between a mast crown and a mast table on a drilling machine includes a double rod hydraulic cylinder connected at a bottom end to a mast table and at a top end to a traveling sheave block; first and second flexible connector members for connecting a drilling head to the mast through the sheave block; and hydraulic feed circuitry for actuating the cylinder to move the sheave block and drilling head alternately in a first pulldown direction and in a second pullback direction.

Abstract: This dust control system is mounted on a drill tower. A housing with an open bottom is used for drawing air into the housing. A side air outlet is used for drawing the dust and chips from the housing to a skimmer. The housing is provided with a pair of longitudinally separated flexible seals with central holes adapted to flexibly receive the drill bit and drill string. The dust hood is movable longitudinally with respect to the drill tower so that the dust hood may be adjusted to a predetermined height above the top of the hole. The hood may be swung from a position aligned with the drill bit and drill string to a position laterally spaced from the side of the drill tower and vice-versa.