| 摘要 |
<p>1,062,671. Boring earth &c. INGERSOLLRAND CO. May 20, 1965 [May 28, 1964], No. 21360/65. Heading E1F. A rotary-percussive, drill for reaming holes comprises fluid actuated percussive drills 6, 7 mounted parallel to a tube 3 and having drill bits 11 which are prevented from digging into the bottom of the hole by rotary cones 25 carried by the tube. When used for "push reaming" the drill rod is fixed to the tube at the end remote from the socket 32 which carries an auger for forcing debris through the pilot hole. When used upwardly as a "pullreamer" the drill is inverted and the rod is fixed to the socket whilst the remote end is plugged. Reference has been directed by the Comptroller to Specification 966,286.</p> |
