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. 29, 2011
Filed:
Nov. 30, 2007
Hong-chin Lin, Glenview, IL (US);
James Eugene Schimpf, Plainfield, IL (US);
James Thomas Ferrier, Elgin, IL (US);
Hong-Chin Lin, Glenview, IL (US);
James Eugene Schimpf, Plainfield, IL (US);
James Thomas Ferrier, Elgin, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
Apparatus and methods are provided for controlling a double-acting hydraulic cylinder during a load-induced rod-extending operation. The apparatus includes a activation circuit and valve for providing a flow path from a pump to the cylinder head end; a flow regeneration circuit and valve fluidly connecting the cylinder rod end and the cylinder head end and configured for providing flow from the rod end to the head end during rod extension; and a controller responsive to rod-extending rate demands and rod-position sensor signals, and operatively connected to the regeneration flow valve and the activation valve. The activation valve also includes a return valve part to control flow from the rod end to the fluid reservoir during rod extension. Both the activation valve and the return valve part are controllable by the controller independently from the regeneration flow valve.