Patent ID: 8210399

Claim:
A dispenser comprising: a housing having a sidewall with a first axial end and a second axial end; a container having a first end portion and a second end portion, the second end portion of the container being engaged with the housing such that the container extends from the first axial end of the housing, wherein the container defines an interior cavity adapted for containing a product; a plunger disposed in the interior cavity of the container, the plunger including a base having a first side and a second side, wherein the interior cavity of the container and the first side of the base cooperatively define a product cavity and the interior cavity of the container and the second side of the base cooperatively define an air cavity; a valve mechanism in engagement with the second end portion of the container, wherein the valve mechanism includes a nozzle defining an orifice and an accumulator defining a pumping chamber, the nozzle and accumulator cooperatively defining a pressure chamber, the pressure chamber being adapted to receive a portion of the product from the product cavity of the container; and a piston selectively slidable within the pumping chamber, the piston being disposed between the product cavity and the pressure chamber, wherein displacement of the piston in one direction within the pumping chamber causes a portion of the piston to compress the portion of the product in the pressure chamber, thereby increasing a fluid pressure of the portion of the product in the pressure chamber to a target fluid pressure for causing the portion of the product to be expelled from the dispenser via the orifice defined by the nozzle, wherein the pressure chamber is disposed between the piston and the orifice defined by the nozzle.