NEEDLE-LESS INJECTOR OF MINIATURE TYPE

摘要

Needleless injectors for liquids are known from the art in a variety of designs that are adapted to different conditions of application. The inventi ve needle- less injector is designed as a hand-held device. It comprises a lockable tensioning system, an energy-storing spring (36), a hollow piston (37) displaceable within a cylinder (38), and a nozzle (39). The hollow piston is provided with a valve body on its one end. The storage container (44) for the liquid is disposed within the hous- ing. The lockable tensioning system is tensioned by counterrotating the two housing parts (31; 32), thereby withdrawing the hollow piston (37) from the cylinder (38). At the same time the amount of liquid required for the injection is withdraw n from the storage container (44) and transported through the hollow piston to the pump chamber (34). When the lockable tensioning system is released, the amount of liq- uid is ejected from the pump chamber through the nozzle. The needleless injector is easy and reliable to handle also for unpracticed people. It is used for intracutaneous injections of a medical liquid into biological tissue, for injecting a liqui d containing an active substance into a plant or for injecting a liquid through a membran e into the space behind said membrane. <IMG>