| abstract |
The invention refers to an auto-injector for delivering a liquid medicament, comprising:n an elongate housing arranged to contain a syringe with a hollow injection needle and a stopper, wherein the syringe is slidably arranged with respect to the housing, spring means capable of, upon activation: pushing the needle from a covered position inside the housing into an advanced position for insertion into the injection site, operating the syringe to inject the dose of medicament, and advancing a needle shroud over the needle for providing needle safety, activating means arranged to lock and release the spring means,n nwherein the spring means is a single drive spring in the shape of a compression spring grounded distally in the housing and proximally bearing against a thrust collar arranged to transmit load from the spring means via a plunger to the syringe and/or the stopper for needle insertion and injection, wherein the plunger is engageable to the thrust collar for joint axial translation, wherein the plunger is disengageable from the thrust collar on relative rotation so as to allow the thrust collar to be advanced further by the drive spring in order to engage the needle shroud for advancing it over the needle. |