The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 18, 1994
Filed:
Mar. 10, 1993
Applicant:
Inventors:
Assignee:
Uniroc AB, Fagersta, SE;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
173133 ; 173128 ; 92177 ;
Abstract
Down-the-hole drilling machine comprising a housing in form of a tube (1), a hammer piston (6) being movable to-and-fro in the tube and intended for impacting a drill bit (5). The hammer piston is at its ends provided with end sections in form of polygons with rounded corners (51, 52). These end sections are turned relative to each other an angle which is half as large as the angle between two adjacent corners.