Patent ID: 8668117

Claim:
A fluid dispenser for containing and dispensing metered amounts of fluid, the fluid dispenser comprising: a reservoir for containing fluid; a chamber positioned substantially within the reservoir for containing a quantity of the fluid; a piston moveable within the chamber to draw fluid into the chamber when the piston is moved in a first direction with respect to the chamber, and to discharge fluid from the chamber when the piston is moved in a second direction opposite the first direction; a user-manipulatable control coupled to the piston and movable to move the piston with respect to the chamber; a pawl movable with respect to the piston to selectively permit and inhibit movement of the piston in at least one of the first and second directions; and a protrusion in slidable mating engagement with respect to a first aperture defined in at least one of the piston and a wall of the chamber to control movement of the piston with respect to the chamber.