Patent ID: 9707356
Date: 2017-07-18
CPC Classifications: A61M

Claim:
1. An auto-injector for administering a dose of a liquid medicament, comprising: an elongate housing; a syringe in the elongate housing, the syringe comprising a hollow needle and a stopper for sealing the syringe and displacing the medicament, the housing having a distal end and a proximal end with an orifice intended to be applied against an injection site, wherein the syringe is slidably arranged with respect to the housing; a spring capable of, upon activation: pushing the syringe from a retracted position inside the housing into an advanced position through the orifice and past the proximal end, operating the syringe to supply the dose of medicament, and retracting the syringe with the needle into the retracted position after delivering the medicament; a trigger arranged to lock the spring in a pressurized state prior to manual operation and capable of, upon manual operation, releasing the spring for injection, wherein the spring comprises a single drive spring in the shape of a compression spring, the drive spring having a proximal end, a distal end, and a ground, and the drive spring being arranged to have its ground in the housing at the distal end of the drive spring for advancing the needle and for injecting the dose of medicament via a plunger and arranged to have its ground in the housing switched to the proximal end of the drive spring for retracting the syringe; an interlock sleeve that is telescoped in the proximal end of the housing, the interlock sleeve translatable in a longitudinal direction between a proximal position and a distal position and biased in a proximal direction in a manner to protrude from the housing in the proximal position, wherein in its proximal position the interlock sleeve is arranged to be coupled to the syringe in the syringe's retracted position, and wherein the interlock sleeve in its distal position is arranged to be decoupled from the syringe; and a syringe carrier holding the syringe and supporting a proximal end of the syringe, the syringe carrier being configured to be telescoped in the interlock sleeve, and the syringe and the syringe carrier being arranged for joint axial translation.