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. 19, 2002
Filed:
Dec. 17, 2001
Bobby E. Rogers, San Diego, CA (US);
Kevin S. Nason, Menlo Park, CA (US);
Gino Kang, Newport Beach, CA (US);
Mission Medical Devices, Inc., San Diego, CA (US);
Abstract
An injection valve includes a housing having an inlet, an outlet, and a fluid channel extending between the inlet and the outlet. A piston is slidable within a bore of the housing between a first position wherein the piston is relatively far from the closed end and a second position wherein the piston is relatively near to the closed end. A biasing spring biases the piston toward the first position. The piston closes and seals the inlet when the piston is in the first position and allows fluid to pass from the inlet to the fluid channel to the outlet when the piston is in the second position. A piston seal is formed between the piston and a wall of the bore, dividing the bore into a unsealed chamber and a sealed chamber adjacent to the closed end. There is no vent between the sealed chamber and an exterior of the housing. Pressure differences between the unsealed chamber and the sealed chamber that adversely affect performance may be minimized by providing a deformable membrane or a gas accumulator communicating with the sealed chamber, or providing an initial pressure differential wherein a gas pressure within the sealed chamber is less than a gas pressure within the unsealed chamber, when the piston is in its first position.