Automatic injection device

Claim 2

An automatic injection device comprising an assembly of a discharge mechanism, a cartridge holder and a cartridge which is slidably accomodated in the cartridge holder, the discharge mechanism comprising a sleeve which is open on one side, a plunger which is movable in the sleeve, a coil spring which acts on said plunger and tries to move same out of the open end of the sleeve outwards, a locking device which cooperates with said plunger so as to prevent undesired movement of the plunger, and, if desired, a safety device to block said locking device, the cartridge comprising a glass ampoule having an injection needle connected thereto, of which ampoule the part remote from the needle has the shape of a hollow cylinder having an entirely or substantially uniform inside diameter, in which is present a piston which can be moved by the plunger, and which ampoule comprises an injection liquid or various injection liquids separated from each other by stoppers, characterized in that a sheath of shrinkable plastic sheet is shrunk around the ampoule entirely or for the greater part.

Claim 3

An injection device as claimed in Claim 1, characterized in that an annular member of a slightly resilient material is present on the open end of the ampoule remote from the needle.

Claim 4

An automatic injection device, comprising an assembly of a discharge mechanism, a cartridge holder and a cartridge which is slidably accomodated in the cartridge holder, the discharge mechanism comprising a sleeve which is open on one side, a plunger which is movable in the sleeve, a coil spring which acts on said plunger and tries to move same out of the open end of the sleeve outwards, a locking device which cooperates with said plunger so as to prevent undesired movement of the plunger, and, if desired, a safety device to block said locking device, the cartridge comprising a glass ampoule having a needle connected thereto, of which ampoule the part remote from the needle has the shape of a hollow cylinder having an entirely or substantially uniform inside diameter, in which is present a piston which can be moved by the plunger, and which ampoule comprises an injection liquid or various injection liquids separated from each other by stoppers, characterized in that an annular member of slightly resilient material is present at the open end of the ampoule remote from the needle.

Claim 5

An automatic injection device, comprising an assembly of a discharge mechanism, a cartridge holder and a cartridge which is slidably accomodated in the cartridge holder, the discharge mechanism comprising a sleeve which is open on one side, a plunger which is movable in the sleeve, a coil spring which acts on said plunger and tries to move same out of the open end of the sleeve outwards, a locking device which cooperates with said plunger so as to prevent undesired movement of the plunger, and, if desired, a safety device to block said locking device, the cartridge comprising a glass ampoule having a needle connected thereto, of which ampoule the part remote from the needle has the shape of a hollow cylinder having an entirely or substantially uniform inside diameter, in which is present a piston which can be moved by the plunger, and which ampoule comprises an injection liquid or various injection liquids separated from each other by stoppers, characterized in that an annular member of slightly resilient material is present at the open end of the ampoule remote from the needle.

Claim 6

An injection device as claimed in Claim 2 or 3, characterized in that the annular member has approximately the same outside diameter as the ampoule, has a slightly smaller inside diameter than the end of the ampoule remote from the needle, and comprises a neck fitting within said end of the ampoule.

Claim 7

An injection device as claimed in any of the preceding Claims, in which the plunger comprises a head facing the piston and forming on the rear side an abutment for the coil spring, a central part of uniform circumference around which the spiral spring fits, and a furcated end part of reduced circumference remote from the piston, the resilient prongs or detent arms of which cooperate with the locking device, characterized in that a sleeve which is open at each end is provided around the end part, the outside diameter of said sleeve being approximately equal to that of the central part of the plunger.

Claim 8

An injection device as claimed in any of the preceding Claims, characterized in that the ampoule is manufactured from unhardened glass.