Patent ID: 7651291

Claim:
A dispenser for dispensing a substance, comprising: a body defining a variable-volume storage chamber for storing the substance; a dispensing portion connected with the body and defining a compression chamber connectable in fluid communication with the storage chamber for receiving substance therefrom, and an outlet aperture coupled in fluid communication with the compression chamber; a one-way valve including an axially-extending valve seat and an axially-extending flexible valve cover overlying the valve seat and defining a normally-closed, axially-extending seam therebetween forming a fluid-tight seal between the valve cover and valve seat, wherein the flexible valve cover is movable relative to the valve seat and the seam is connectable in fluid communication with the outlet aperture to allow the passage of a predetermined amount of substance through the seam and out of the dispenser; a manually engageable actuator adjacent to the compression chamber and defining a manually depressible portion movable between first and second positions and normally biased in the direction from the second position toward the first position, wherein (i) during movement of the manually depressible portion from the second position toward the first position the compression chamber is in fluid communication with the variable-volume storage chamber for permitting substance to flow from the variable-volume storage chamber into the compression chamber, and (ii) during movement of the manually depressible portion from the first position toward the second position the compression chamber is not in fluid communication with the variable-volume storage chamber and a portion of the of the manually depressible portion extends at least partially into the compression chamber to pressurize the substance within the compression chamber above an opening pressure of the one-way valve and, in turn, dispense the substance through the normally closed seam of the one-way valve and out of the dispenser; and a piston slidably received within the body and forming a substantially fluid-tight seal therebetween, wherein the variable-volume storage chamber is formed between the piston and the compression chamber, and the piston is movable toward the compression chamber upon dispensing a dosage from the storage chamber to reduce the volume of the storage chamber in an amount approximately equal to the volume of the dose dispensed.