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.

Date of Patent:
Jun. 19, 2012

Filed:

Jan. 23, 2008
Applicant:

Kurt Andersson, Tyresö, SE;

Inventor:

Kurt Andersson, Tyresö, SE;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A method for controlling a fluid operated percussive device, which inside an axially extending cylinder room () of a housing () of the percussive device includes a to and fro moveable percussive piston (), which is adapted for performing strikes in a striking direction (A) and which includes a signal portion () for controlling a main valve (), which is adapted to intermittently transmit pressure fluid to at least one driving chamber () for the percussive piston. An auxiliary valve () is controlled for transmitting fluid contact between at least one auxiliary channel means () with a channel opening in the cylinder room (), and the main valve () over the signal portion (), for switching the main valve () before the percussive piston, in operation, has reached at least one of said regions. The invention also concerns a percussive device and a rock drilling machine.


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