Improvements in Drilling Machines for Drilling Holes in Rock or Coal for Blasting or similar Purposes.

摘要

6984. Burnside, G. April 3. Rock drills, rotary. Ratchet drills for coal &c. are held in a short hole in the face by wedges B and plates A attached to the frame, thus avoiding the use of a separate support. The twisted drill I fits on to either end of the feed-screw D, which is worked through the feed-nut E by the ratchet handle P. The feed-nut is held on the frame C by pins K, so that it can be taken out and reversed when changing drills. This drill may also be used with a support, the end A B being held against it and the drill being fitted to the outer end of the screw. In that case, the inner end of the screw may carry a guide-piece, which works on the sides of the frame C.