| 摘要 |
<p>A needleless injector includes a barrel (5) for receiving an injectable liquid a nozzle (82) closing one end of the barrel (5) containing an injection orifice; a plunger (46) movable in the barrel (5) for forcing liquid out of the barrel (5); a piston (6); in the barrel (5) for forcing liquid out of the barrel (5); a piston (6) in the barrel (5) for movement under gas pressure to move the plunger (46); a valve (118) for admitting gas under pressure into the barrel (5) behind the piston (6); a trigger (116) for opening the valve (118) to cause said piston (6) to move against the plunger (46); and a magnet (10) for retaining the piston (6) in a rest position in said barrel (5) until acted upon by a gas under sufficient pressure to cause the piston (6) and plunger (46) to move to an extended, discharge position. For extra protection a sterile pad can be disposed between the injection orifice and the skin of a person or animal receiving an injection.</p> |
