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US 2004/0000658 A1Published application
Valve assembly
AssigneeGeneral Motors Corporation
InventorsKevin R. Wayman, Drew A. Crafton, Joel E. Mowatt
Life of this patent
Estimating the term…
Abstract
A valve assembly has a valve body with a bore formed therein. A valve spool is slidably disposed in the valve body. The valve spool has a plurality of valve lands that closely engage the valve bore to form substantially leak-free interfaces. The leading land has a diameter less than the land immediately adjacent thereto in a range of 0.34 mm to 0.17 mm, and a recess formed between the leading land and the first adjacent land. The recess has an inner diameter at least 0.75 mm less than said diameter of said leading land.
Claims3
A valve assembly comprising:
- a valve body including a valve bore and a plurality of fluid passages substantially perpendicular to and intercepting said valve bore;
- a valve spool slidably disposed in said valve bore having a plurality of land portions with sealing diameters, at least one valley portion between adjacent land portions, a leading land portion formed on one end of said valve spool having a diameter smaller than said sealing diameter on a first land adjacent thereto in a range of 0.34 mm to 0.17 mm, and a recess formed between said leading land and said first adjacent land, said recess having an inner diameter at least 0.75 mm less than said diameter of said leading land;
- and
- a spring disposed between said valve spool and a spring retaining member to urge the valve spool into the valve bore.
1 more element
Dependencies are inferred from the claim text.