Patent ID: 6096002
Filing Date: 2000-08-01
Classification: A61M

Abstract:
A needle-less hypodermic jet injection device comprising:a hand piece assembly having a body for holding a drug injection cartridge with medication cylinder, injection nozzle, and drug-injection piston; said hand piece assembly defining a first bore within said body for movably receiving a gas-power piston, a gas power piston movably received in said bore and having a ram portion extending into said drug injection cartridge to abut with said drug-injection piston, said body and gas-power piston cooperating to define a first variable-volume chamber in said first bore;said body also defining an elongate second bore in gas communication with said first bore and separated therefrom by a center wall portion of said body, said body carrying a sealing member circumscribing said second bore and disposed along the length thereof so as to be sealingly engageable with a cylindrical gas capsule when said capsule is received into said second bore, said gas capsule having a penetrable wall section disposed toward said center wall, and said sealing member cooperating with said gas capsule to define a second variable-volume chamber in said second bore the volume of which varies in response to movement of said gas capsule in said body relative to said center wall;said center wall carrying a penetrator means to penetrate said penetrable wall section of said gas capsule, and said hand piece assembly carrying a discharge mechanism including a trigger outwardly disposed on said body and a hammer movable in said body in response to actuation of said trigger to forcefully move said gas capsule in said second bore so as to impale said gas capsule at said penetrable wall section thereof upon said penetrator and to communicate pressurized gas to said first chamber;whereby, said pressurized gas in said first chamber drives said gas-power piston to effect a hypodermic jet injection from said drug injection cartridge, and pressurized gas communicated from said gas capsule into said second chamber moves said gas capsule sealingly relative to said sealing member to push back said hammer and reset said trigger.