| abstract |
Needle-less injectors for liquids are known in many different forms which are adapted to different conditions of use. The needle-less injector according to the invention is in the form of a hand-held unit. It includes a locking stressing mechanism, an energy-storing spring ( 36 ), a hollow plunger ( 37 ) displaceable in a cylinder ( 38 ) and a nozzle ( 39 ). At its one end, the hollow plunger is provided with a valve body ( 42 ). The supply container ( 44 ) for the liquid is arranged within the housing. When the locking stressing mechanism is stressed by rotation of the two housing portions ( 31, 32 ) relative to each other the hollow plunger ( 37 ) is drawn out of the cylinder ( 38 ); at the same time the amount of liquid required for an injection is conveyed out of the supply container ( 44 ) through the plunger into the pump chamber ( 43 ). After the locking stressing mechanism is triggered the amount of liquid is expelled from the pump chamber through the nozzle. The needle-less injector can be safely and easily handled, even by unskilled persons. It is used for the intracutaneous injection of a medicament-bearing liquid into biological tissue, for the injection of an active substance-bearing liquid into a plant, or for the injection of a liquid through a membrane into the space behind the membrane. |