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:
Dec. 06, 2011
Filed:
Jul. 21, 2008
Francisco Green, Dayton, OH (US);
Francisco Green, Dayton, OH (US);
Caterpillar Trimble Control Technologies, LLC, Dayton, OH (US);
Abstract
A control is provided for a machine that applies a material to a subgrade and pulls a floating screed over the top surface of the material behind the machine. The floating screed is attached to the machine by at least one tow arm at a tow point on the tow arm. The vertical height of the tow point is controlled by a hydraulic cylinder on the machine in response to a valve control signal applied to a hydraulic valve. The screed determines the thickness of the material on the subgrade as it is manipulated by adjusting the height of the tow point such that the top surface of the material follows a reference surface. A first sensor is mounted on the machine, adjacent the front of the machine, for sensing the relative height of the reference surface and providing a first sensor output related thereto. A second sensor for senses the height of the tow point relative to the machine and provides a second sensor output related thereto. This can be accomplished directly, or by sensing the height of the tow point with respect to the reference surface and subtracting the portion of the this sensed height attributable to changes in the reference surface. A control circuit, responsive to the first sensor output and the second sensor output, provides a valve control signal to the hydraulic valve for control of said hydraulic cylinder.