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:
Nov. 17, 2020
Filed:
Apr. 12, 2019
Applicant:
Caterpillar Inc., Deerfield, IL (US);
Inventors:
Nathan A. Ruetten, Peoria, IL (US);
Carl J. Moberg, Dunlap, IL (US);
Assignee:
Caterpillar Inc., Peoria, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 44/02 (2006.01); E21B 19/086 (2006.01); E21B 7/02 (2006.01);
U.S. Cl.
CPC ...
E21B 7/022 (2013.01); E21B 19/086 (2013.01); E21B 44/02 (2013.01); E21B 7/025 (2013.01);
Abstract
A control system for a drilling machine includes a vertically movable and rotatable drill string having a drill bit at a distal end, a hydraulic cylinder coupled to the drill string to provide a motive force for the vertical movement of the drill string, the hydraulic cylinder having an extend chamber and a retract chamber, a counterbalance valve selectively opening to fluidly couple the retract chamber to a drain, and a holdback valve selectively controlled to adjust the opening of the counterbalance valve based on a weight of the drill string.