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:
Mar. 21, 1995
Filed:
Jul. 01, 1993
Applicant:
Inventor:
Hans E Edlund, Roanoke, VA (US);
Assignee:
Reedrill, Inc., Denison, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21C / ; E21B / ;
U.S. Cl.
CPC ...
173206 ; 173210 ; 92209 ;
Abstract
In an impact drilling apparatus, an impact hammer is provided that includes a body portion and a piston head on the body portion. The piston head has a larger outer periphery than the body portion. The body portion and the piston head have substantially the same cross-sectional area at all points along a longitudinal axis of the hammer. The piston head is disposed at one end of the body portion and is funnel-shaped.