Fluid dispenser
AssigneesGlaxo Group Limited, MeadWestvaco Calmar, Inc.
InventorJames Terence Collins
Life of this patent
Estimating the term…
Abstract
One aspect of the invention provides a component for a fluid dispenser which defines a dosing chamber for a piston member to stroke in and has an end adapted for engaging a fluid outlet of the fluid dispenser or a seal which overlies the fluid outlet to selectively close and open the fluid outlet or seal. Other aspects are disclosed herein.
Claims50
A fluid dispenser for use with a fluid supply, the dispenser having a dosing chamber, a fluid outlet, and a piston member which is arranged to sealingly stroke in the dosing chamber (i) in a first direction for filling the dosing chamber with fluid from the supply, and (ii) in a second direction to dispense fluid from the dosing chamber towards the fluid outlet, wherein the dosing chamber has first and second sections of different widths, the first section is narrower than the second section and located in the second direction relative to the second section, and the piston member is in constant sealing contact with the second section as it strokes in the first and second directions, but only in sealing contact with the first section in a portion of the strokes in the first and second directions.
A fluid dispenser for use with a fluid supply having a dosing chamber, a piston mounted to reciprocate forwardly and rearwardly in the dosing chamber, the piston having a seal to sealingly slide on a wall of the dosing chamber, wherein a rearward stroke of the piston enables the dosing chamber to fill with fluid from the fluid supply and a forward stroke of the piston pumps fluid present in front of the piston out of the dosing chamber, and wherein the seal is adapted in use to come out of sealing contact with the dosing chamber wall during the rearward stroke to enable fluid to flow forwardly past the seal into the dosing chamber in front of the piston.
A fluid dispenser for use with a fluid supply having a dosing chamber having an outlet, a valve biased to close the outlet, a piston mounted to reciprocate forwardly and rearwardly in the dosing chamber, wherein a rearward stroke of the piston enables the dosing chamber to fill with fluid from the fluid supply and a forward stroke of the piston pumps fluid present in the dosing chamber through the outlet in the dosing chamber, wherein the dispenser is configured and arranged such that the valve is kept open against the valve bias at the end of the forward stroke of the piston member.
Dependencies are inferred from the claim text.