NEEDLE-LESS INJECTOR

摘要

A needle-less injector comprises a cartridge (3) prefilled with liquid (9), which cartridge contains a free sliding piston (32) and an injection orifice (10). A ram (22) is urged by a pre-loaded spring (24) for striking the said piston to cause the injections. Adjusting means (6) can be provided to vary the volume injected. A trigger device (26, 30) initiates injection only when the optimum contact pressure is reached between the discharge orifice (1) and epidermis of the subject. The initial loading of the power spring (24) is sufficient to dispense all of the contents of the medicament cartridge in one dose or multiple sequential doses. Disposable and reusable embodiments are described.