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. 02, 2026
Filed:
Oct. 02, 2024
Wanner Engineering, Inc., Minneapolis, MN (US);
Richard D. Hembree, Port Coquitlam, CA;
WANNER ENGINEERING, INC., Minneapolis, MN (US);
Abstract
A pump includes a cylindrical plunger chamber having an inward projecting radial seal. A plunger moves with a reciprocating stroke within the cylindrical plunger chamber, the plunger having a first diameter, and a second diameter less than the first diameter, the radial seal engaging the plunger at the second diameter for an entire length of the stroke of the plunger. A pressure balancing valve is in fluid communication with the pumping chamber and the hydraulic oil chamber. A fluid passage connects to the plunger chamber at a position between the radial seal and the first diameter of the plunger and leads to the pressure balancing valve. A radial clearance is between the cylinder and the second diameter, and a seal between the first portion and the cylinder having a clearance smaller than the radial clearance allows hydraulic fluid to escape past the seal during a plunger stroke.