Needleless injector accessories

A nozzle assembly for use on the discharge end of the barrel of a needleless injector comprising a holder for mounting in the discharge end of the barrel and a disposable nozzle for mounting on the holder,

• The holder including:
• a tubular holder body having a central, longitudinally extending passage therethrough permitting the passage of fluid from the injector barrel to the disposable nozzle;
• an externally threaded holder nozzle at the front, discharge end of the holder body;
• a cylindrical sleeve on the holder body around the rear end of said externally threaded holder nozzle;
• and
• at least one first notch in a front, free end of the sleeve;
• the disposable nozzle including:
• a tubular, internally threaded nozzle body having external threads for mounting the disposable nozzle on the front end of the holder;
• an annular recess with inner and outer walls in a rear end of the nozzle body for receiving the sleeve of the holder when the disposable nozzle is mounted on the holder, and
• a resilient, frangible detent extending outwardly at an acute angle from said inner wall of said recess into the path of travel of the holder sleeve when the disposable nozzle is being threaded onto the holder,
• whereby, when the disposable nozzle is rotated in one direction while being threaded onto the holder, the detent is deflected towards said inner wall of the recess, and when the disposable nozzle is fully on the holder, the detent extends into the at least one first notch and reverse rotation of the disposable nozzle results in breaking of the detent.