Shield Lock for Spring Driven Injection Device

摘要

The present invention relates to an injection device for automatic torsion spring driven injection of a liquid drug. The injection device is of the type wherein a telescopically movable needle shield (20) activates the release of the torque of the torsion spring to drive the injection when the needle shield is moved from its extended position to a retracted position. The injection device is provided with a needle interface (30) carrying the injection needle, which needle interface is provided with means (32) preventing axial movement of the shield when no injection needle is mounted. Further, other means are provided to restrain the needle shield in the retracted position when the injection device is its “zero” position such that a user has access to the injection needle in order to exchange the injection needle.

主权项

1. A spring driven drug delivery device for delivering set doses of a liquid drug comprising:
a housing fixating a cartridge containing the liquid drug to be injected, a needle interface to which an injection needle is mountable, a needle shield for covering the injection needle during use, wherein, the needle shield under influence of a spring is axially slidable relatively to the needle interface and which needle interface is provided with a number of flexible arms preventing axial movement of the needle shield when no injection needle is mounted on the needle shield and which arms are activated when an injection needle is mounted on the needle interface thereby allowing the needle shield to move axially relatively to the needle interface.