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US 4,694,977 AGranted
Fluid dispenser
AssigneeIng. Erich Pfeiffer GmbH
InventorsLothar Graf, Leo Maerte, Thomas Skorka
Life of this patent
Estimating the term…
Abstract
A vacuum-tight and pressure-tight closed storage space in a container is constructionally combined with a thrust piston pump projecting thereinto and a drag piston slidably guided therein and in the initial position of the thrust piston pump is hermetically sealed by an exhaust valve mechanically closed in forcibly controlled manner. The drag piston is adapted to the thrust piston pump in such a way that the storage space can be emptied substantially free with the thrust piston pump.
Claims12
A fluid dispenser, comprising:
- a storage container defining a storage space extending between two opposite ends of the storage container;
- a drag piston displaceable in the container and tightly sealing the storage space at one of its ends by means of a piston ring sealing said drag piston against the storage container;
- a piston pump having a pump cylinder in a cylinder casing with an external shape arranged in the container at the end of the storage space opposite to the drag piston in said storage space, means defining a fluid discharge outlet leading from said pump cylinder to an area outside of the dispenser, a fluid inlet for said pump cylinder, said fluid inlet being connected to the storage space, and a pump piston displaceable in the pump cylinder along a pump axis between a pump stroke end and an initial end of a piston stroke by a handle, the piston pump forcing fluid from the fluid inlet to the fluid discharge outlet, the pump cylinder being substantially axially parallel to the drag piston, the drag piston having an inner side facing the piston pump and an outer side facing away from said inner side, said inner side defining a cup-like cavity with an internal cross-section for receiving a portion of the piston pump extending into the storage space, such that said portion of the piston pump fills the cavity of the drag piston when the storage space is empty, wherein the fluid inlet and the cylinder casing of the piston pump project into the storage space, defining a projecting cylinder casing portion thereof, the drag piston having an adapting cup forming the cavity, said cavity having an internal cross-section substantially precisely adapted to an external shape of the projecting cylinder casing portion, such that said cylinder casing portion fills the cavity of the drag piston when the storage space is emptied, said adapting cup being disposed radially inside the piston ring and extending axially past the outer side of the piston ring.
Dependencies are inferred from the claim text.