Foil sealed syringe

Claim 1

A syringe unit, comprising a cylindrical liquid container with a push-out piston, movable in said liquid container between a container-full position and a container-empty position, and an actuating device for moving said push-out piston so as to push out liquid, said actuating device beint detachably connected to said liquid container and said push-out piston, and comprising a sleeve, one end of said sleeve detachably connected to said liquid container, an actuating rod guided in said sleeve, one end of said actuating rod in engagement with said push-out piston, a helical coil compression spring supported in said sleeve and acting with said actuating rod, a locking-slide passing axially through said sleeve, said locking-slide having an aperture, said actuating rod having a shoulder interacting with said aperture so as to pass through said aperture when said locking slide is in a releasing position and to be retained when said locking slide is in a retaining position, the compression spring being compressed when said shoulder is retained, the outer end of said liquid container being sealed by pierceable foil, said actuating rod being adapted to pierce said foil and engage said push-out piston when in a released position.