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:
Aug. 14, 2001
Filed:
May. 19, 2000
Applicant:
Inventors:
Assignee:
Sandvik Tamrock Oy, , FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B25D 9/00 ; E21D 4/06 ;
U.S. Cl.
CPC ...
B25D 9/00 ; E21D 4/06 ;
Abstract
An arrangement in a rock drill comprising a shank and a percussion piston and lifting sleeve for moving the shank towards percussion piston, and a method of controlling rock drilling. The arrangement comprises a lifting sleeve around the shank and a plurality of cylindrical lifting pistons around the shank. In the method, upon downward drilling, the magnitude of the feed force of the rock drill is decreased as the number of extension rods increases, and a force is set to act on some lifting pistons to move the shank towards the percussion point.