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:
Apr. 15, 1997
Filed:
Mar. 17, 1995
Dwight B Stephenson, Burnsville, MN (US);
Kenneth G Rasmussen, Maple Grove, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A fluid controller (17) is disclosed of the type including a relatively rotatable valve spool (95) and valve sleeve (97) which define a series of variable control orifices (71-76) during normal steering operations. Fluid flow to a control port (27) is controlled by a variable control orifice (74). During small steering corrections, at relatively small valve displacements, the present invention provides an additional variable control orifice (155), which opens before the control orifice (74) opens. A form of check valve (153) is in series with the additional orifice (155), and downstream thereof, to prevent reverse flow from the control port (27) through the controller. The invention is especially beneficial in controllers of the dynamic load signal type including a load signal drain orifice (76) which is open to the system reservoir (R) at the relatively small displacements.