Patent ID: 7261224

Claim:
A pump for administering doses of fluid, said pump comprising: a reservoir formed to accommodate at least one of the doses of fluid; a fluid-collecting chamber in communication with said reservoir; a piston disposed to reversibly slide within at least a dose-control portion of said fluid-collecting chamber, wherein, with the pump being in a quiescent state, said piston not sealing or substantially sealing said dose-control portion from other portions of said fluid-collecting chamber, wherein, upon actuation of the pump, said piston seals or substantially seals said dose-control portion from other portions of said fluid-collecting chamber with said piston sliding within said dose-control portion, and wherein said piston being configured to displace a volume of fluid from said sealed or substantially sealed dose-control portion which is approximately equal to or greater than the volume of one of the doses of fluid; an actuator engageable to cause movement of said piston and actuation of said pump, said actuator being configured to be engaged at a location spaced from said piston to cause movement of said piston; a nozzle, wherein said nozzle being located such that fluid displaced by said piston from said dose-control portion is generally urged towards said nozzle; and a regulator disposed between said dose-control portion and said nozzle to selectively control flow therebetween, wherein, upon actuation of the pump, said regulator being initially in a closed state.