Patent ID: 8105272

Claim:
A needle-free injection device comprising: a drug delivery system including a nozzle having a drug chamber and an outlet orifice, the drug delivery system adapted to expel a volume of liquid from the drug chamber through the outlet orifice; an actuation system including: an injection force assembly comprising a source of pressurized gas adapted to transmit a driving force to the drug delivery system, and a spring-driven hammer member adapted to engage the source of pressurized gas with the drug delivery system by urging the source of pressurized gas towards a pierce pin to release the pressurized gas; a trigger assembly adapted to operatively couple the actuation system with the drug delivery system, the trigger assembly including a retaining member adapted to limit activation of the injection force assembly; and a recoil restriction system adapted to limit movement of the injection force assembly and including a recoil member having a first end coupled to the hammer member and a second end adapted to engage with the retaining member.