Drug injection device with automatic needle retraction after injection

摘要

An automatic medication injection device including a driver (95), a retractor (190, 230) and a blocking member (180). Upon device triggering the driver is shifted proximally to move a device syringe, expel medication from the syringe0, and then to disengage itself from the syringe plunger. The driver and the blocking member have a complementary camming configuration by which the blocking member, during the driver shifting, is automatically rotated from a first rotational orientation to a second rotational orientation. The blocking member blocks retraction of the retractor when disposed in the first rotational orientation, and permits retraction of the retractor when disposed in the second rotational orientation, which retractor retraction withdraws the device syringe from an injecting position to a retracted position.