Patent ID: 7131559

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 fluid communication with said reservoir, said fluid-collecting chamber including a dose-control portion which encompasses a volume defined by two dimensions; a piston disposed to reversibly slide within at least said dose-control portion so as to selectively displace at least a portion of fluid collected in said dose-control portion, wherein, with the pump being in a quiescent state, said piston is spaced from said dose-control portion; a nozzle, wherein said nozzle is located such that fluid displaced by said piston from said dose-control portion is generally urged towards said nozzle; and, at least one check valve disposed between said dose-control portion and said nozzle to selectively control flow, wherein said reservoir has a reduction in volume in response to reduction in fluid accommodated therein.