Patent ID: 8608684

Claim:
A jet expelling assembly, comprising: a housing, a reservoir adapted to contain a fluid drug and comprising an outlet, and an impulse chamber assembly comprising: a chamber portion defining a cavity having a general axis, a piston slidably received in the cavity along the general axis and comprising a fluid inlet and a fluid outlet, the cavity and the piston in combination defining a variable-volume impulse chamber, the inlet comprising a generally straight conduit protruding from the piston and arranged generally in parallel with the general axis, the conduit being adapted to slidably engage the reservoir outlet during relative movement therebetween, and a fluid outlet nozzle in fluid communication with the impulse chamber, wherein the reservoir outlet comprises a self-sealing septum, and the conduit comprises a pointed proximal end adapted to penetrate the self-sealing septum, wherein the self-sealing septum is adapted to reseal itself, and wherein when expelling an amount of drug from the reservoir to the impulse chamber via the inlet the chamber portion is arranged stationary relative to the reservoir, and the piston moves towards the reservoir, the impulse chamber thereby receiving the expelled amount of drug.