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:
Jun. 26, 2001
Filed:
Feb. 10, 1999
Alan W. Johnson, Ames, IA (US);
Sauer-Danfoss Inc., Ames, IA (US);
Abstract
A filled hydraulic piston assembly includes a piston body having first and second ends and a compartment in the piston body extending inwardly from the second end toward the first end. The piston is filled with an insert element which is inserted into the compartment of the piston and then held therein by pushing an annular lip on the second end of the body inwardly and against the adjacent end of the insert element. The insert element is comprised of a material that is less dense than the material of the body but has a higher bulk modulus than hydraulic oil. Oil channels can be formed in a variety of shapes on or around the insert so that oil may flow through the filled piston. The piston insert element can be formed from a variety of materials, such as plastic, magnesium, aluminum or other nonferrous metals. The body is generally comprised of steel.