Disposable injector cap

1. An injector cap for an ampoule support, comprising:

a sliding sleeve mounted slidably on said ampoule support, wherein said sliding sleeve is initially forced by a pre-tensioning means into a first position in which the sliding sleeve covers a cannula, and wherein said sliding sleeve can be slid against the pre-tensioning means into a second position in which said cannula emerges from a front facing end of said sliding sleeve such that medication may be administered and wherein the sliding sleeve returns to the first position after the medication is administered; and

a blocking means for non-detachably blocking the sliding sleeve against sliding again into the second position when the sliding sleeve has been returned from the second position to the first position, wherein an inner surface of the sliding sleeve is provided with at least two protrusions protruding radially inwardly from the inner surface of the sliding sleeve, and wherein the blocking means includes a locking ring disposed inside and proximate at a front end of the sliding sleeve when the sliding sleeve is initially forced by the pre-tensioning means into the first position, and the locking ring is engageably moved along with the cannula back to the first a locking position, wherein the locking ring includes at least two locking elements protruding radially outward, and, upon return of the sliding sleeve to the first position, the at least two protrusions on the sliding sleeve abut the at least two locking elements on the locking ring to help block the sliding sleeve against sliding again into the second position when the sliding sleeve has been returned from the second position to the first position.

2. The injector cap as set forth in claim 1 , wherein said blocking means comprises locking means for locking locks said sliding sleeve relative to a fixed part of said ampoule support once the sliding sleeve has returned to said first position.

3. The injector cap as set forth in claim 1 , wherein the locking ring is slidably mounted in said sliding sleeve and locks in behind a locking protrusion of a cannula support fastened to said ampoule support when said sliding sleeve is slid into said second position.

4. The injector cap as set forth in claim 3 , wherein said locking ring comprises locking clips arranged circumferentially and converging inwards, said locking clips locking in behind said locking protrusion.

5. The injector cap as set forth in claim 3 , wherein said locking ring at least two locking elements comprises comprise spacer clipswhich said sliding sleeve pushes against, via elastic stays, once said sliding sleeve has returned to said first position.

6. The injector cap as set forth in claim 5 , wherein said sliding sleeve comprises a stopper for said spacer clips of said locking ring which, when said sliding sleeve is transferred from said first position to said second position, slides said locking ring over said cannula support until said locking clips lock in behind said locking protrusion.

7. An injector, comprising:

an ampoule support; and

an injector cap, said injector cap comprising:

a sliding sleeve mounted slidably on said ampoule support, wherein said sliding sleeve is initially forced by a pre-tensioning means into a first position in which the sliding sleeve covers a cannula, and wherein said sliding sleeve can be slid against the pre-tensioning into a second position in which said cannula emerges from a front facing end of said sliding sleeve such that medication may be administered and wherein the sliding sleeve returns to the first position after the medication is administered; and

a blocking means for non-detachably blocking the sliding sleeve against sliding again into the second position when the sliding sleeve has been returned from the second position to the first position, wherein an inner surface of the sliding sleeve is provided with at least two protrusions protruding radially inwardly from the inner surface of the sliding sleeve, and wherein the blocking means includes a locking ring disposed inside and proximate at a front end of the sliding sleeve when the sliding sleeve is initially forced by the pre-tensioning means into the first position, and the locking ring is engageably moved along with the cannula back to the first a locking position, wherein the locking ring includes at least two locking elements protruding radially outward, and, upon return of the sliding sleeve to the first position, the at least two protrusions on the sliding sleeve abut the at least two locking elements on the locking ring to help block the sliding sleeve against sliding again into the second position when the sliding sleeve has been returned from the second position to the first position.

8. The injector as set forth in claim 7 , wherein at least one of said injector cap and cannula support is attached to said ampoule support via a thread means.

9. An injector cap for use on an injection device, comprising:

a sliding sleeve movably mounted on a portion of the injection device, wherein the sliding sleeve is initially forced by a pre-tensioning member into a first position covering a needle carried by the injection device and can be moved against the pre-tensioning member into a second position in which the needle emerges from the sliding sleeve such that medication may be administered and wherein the sliding sleeve returns to the first position after the medication is administered; and

a lock which non-releaseably locks the sliding sleeve against moving back to the second position when the sliding sleeve has been returned from the second position to the first position, wherein an inner surface of the sliding sleeve is provided with at least two protrusions protruding radially inwardly from the inner surface of the sliding sleeve, and wherein the lock includes a locking ring disposed inside and proximate at a front end of the sliding sleeve when the sliding sleeve is initially forced by the pre-tensioning member into the first position, and the locking ring is engageably moved along with the needle back to the first a locking position, wherein the locking ring includes at least two locking elements protruding radially outward, and, upon return of the sliding sleeve to the first position, the at least two protrusions on the sliding sleeve abut the at least two locking elements on the locking ring to help block the sliding sleeve against sliding again into the second position when the sliding sleeve has been returned from the second position to the first position.

10. The injector cap according to claim 9 , wherein the sleeve slides.