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. 13, 1990
Filed:
Aug. 29, 1988
Michel A Pierrat, Boulder, CO (US);
Other;
Abstract
A fluid pump has two pairs of rectangular oppositely-disposed pistons. The pistons of each pair travel simultaneously in opposite directions at the same speed and over the same distance. Valving is provided by a reciprocating port plate, in face-to-face relation to the piston, driven in a circular path from two spaced crankpins and which in turn drives the associated piston. The sliding movement of the port plate controls the alignment of inlet and exhaust ports in the piston and port plate. The excursion or 'throw' of the pistons can be varied from zero to maximum. A crankpin throw-adjusting mechanism simultaneously adjusts the throw of each crankpin, some in one direction, some in the opposite, so that all chambers are automatically adjusted for varying, but always identical, displacements. Self-lubricated seals between the piston and chamber walls are spring loaded, by an elastomerically sealed structure having non-linear deflection-to-force characteristics.