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:
Nov. 27, 2007
Filed:
Jun. 05, 2001
Thomas H. Stockmann, Ingersoll, CA;
Thomas H. Stockmann, Ingersoll, CA;
Saf-Holland Equipment Limited, Norwich, Ontario, CA;
Abstract
A hydraulic platform lift, having hydraulic pump means and first and second hydraulic cylinders each having a piston member therein, each operatively coupled to a respective side edge of a platform to permit raising and lowering of the platform. A positive displacement valve is further provided, with the hydraulic platform lift and comprises a pair of juxtaposed cylinder members, each containing a longitudinally-movable piston, such pistons operatively coupled to each other so that movement of one piston causes an equal movement of the other. The positive displacement valve is adapted, when the pump means provides pressurized hydraulic fluid via a respective aperture to a first side of each of the pistons, to cause the pistons to be displaced an equal distance causing an equal egress of hydraulic fluid from the cylinder members via a respective aperture.