Self venting plunger
AssigneeSunoco Products Company
InventorDavid E. Boring
Life of this patent
Estimating the term…
Abstract
A self-venting cartridge plunger including openings defined therein and forming through air passages, each opening having an associated valve flap hinge-joined to the plunger and movable to close the opening upon the plunger encountering a greater resistance to movement than the flow of evacuating air.
Claims15
A self-venting plunger for use in the dispensing of viscous material contained within a dispensing tube, said plunger comprising a leading panel, a peripheral wall integral with and extending rearward of said leading panel, at least one vent opening defined through said plunger forward of said peripheral wall and defining an air path through said plunger for free discharge of air therethrough as said plunger is moved inwardly within a dispensing tube toward contained viscous material, and a valve flap mounted on said plunger and movable between a forward open position remote from said at least one opening for free flow of air thereby and through said at least one opening, said valve flap being selectively movable to a second closed position closing said at least one opening upon encountering resistance to inward movement of said plunger greater than that of an air flow thereby.
An air-venting plunger for a dispensing tube for viscous materials, said plunger comprising a leading face and a peripheral wall extending rearward from said leading face for a plunger-guiding engagement within a dispensing tube with said leading face forwardly directed for selected movement into dispensing engagement with a tube-contained viscous material, air venting means in said plunger for unencumbered air flow rearwardly through said plunger relative to said leading face upon forward movement of said plunger, valve means adjacent said venting means for closing said venting means, and means both for retaining said valve means in an open position remote from said venting means for allowing air flow through said venting means, and for allowing movement of said valve means to a closed position closing said venting means upon encountering a material of greater resistance to flow than air.
Dependencies are inferred from the claim text.