초록 ▼

A needleless injector for injecting medication through the skin of a patient includes a vial which holds a volume of liquid medication. The vial includes a vial piston which moves to force the liquid medication out of the vial. A power mechanism applies force to the vial piston. The power mechanism

A needleless injector for injecting medication through the skin of a patient includes a vial which holds a volume of liquid medication. The vial includes a vial piston which moves to force the liquid medication out of the vial. A power mechanism applies force to the vial piston. The power mechanism includes a power piston which has a plurality of ratchets. A spring is positioned to apply force to the power piston. A trigger engages the ratchets on the power piston to hold the power piston in place against the force applied by the spring. The trigger selectively releases the power piston so that the power piston moves in response to the force applied by the spring. The power piston applies the force to the vial piston to cause the vial piston to force the liquid medication out of the vial. A cocking mechanism applies force to the power piston to move the power piston against the force of the spring to engage the ratchets. A travel adjustment mechanism is moveable to position the spring within the power mechanism to control the movement of the power piston and to thereby control the volume of liquid ejected from the vial.

대표청구항 ▼

[ What is claimed is:] [1.] A needleless injector which injects medication through the skin of a patient, the needleless injector comprising:a vial which holds a volume of liquid medication, said vial comprising a vial piston which moves to force said liquid medication out of said vial; anda power m

[ What is claimed is:] [1.] A needleless injector which injects medication through the skin of a patient, the needleless injector comprising:a vial which holds a volume of liquid medication, said vial comprising a vial piston which moves to force said liquid medication out of said vial; anda power mechanism which applies force to said vial piston, said power mechanism comprising:a power piston having a length and opposite sides, said power piston having ratchets formed in a symmetrical arrangement alone said opposite sides;a spring having a first end and a second end, said first end of said spring positioned to apply force to said power piston;a pair of independent triggers on opposite sides of said piston, each of the triggers independently engaging said ratchets on said power piston to hold said power piston in place against a force applied by said spring and which selectively release said power piston in response to the concurrent oppression of said triggers, the power piston being released to move in response to said force applied by said spring, said power piston applying said force to said vial piston to cause said vial piston to force said liquid medication out of said vial;a cocking mechanism, said cocking mechanism applying force to said power piston to move said power piston against the force of said spring to engage said ratchets, so that the inadvertent release of said power piston is avoided by requiring the concurrent oppression of the opposing triggers before the volume of liquid is ejected from said vial.