Non-dosing cartridge for an injection device

摘要

A device for automatically injecting a material into the body is disclosed. The device includes a drive assembly and a disposable assembly including a syringe which is mounted to the drive assembly. The drive assembly includes a drive rod, a driver releasably coupled to the drive rod, and a spring which urges the drive rod towards the syringe assembly. The spring first urges the coupled drive rod and driver along the axis of the device, causing the skin to be penetrated by the needle of the syringe assembly. The drive rod is then decoupled from the driver. The spring continues to urge the drive rod in the axial direction, whereby the drive rod engages a piston in the syringe assembly and causes the displacement of the material therein. A cap is removably mounted to the disposable assembly. Locking members on the cap and disposable assembly prevent removal of the cap until the disposable assembly is moved to the firing position within the drive assembly. A lock release assembly including cooperating elements on the drive assembly and disposable assembly causes disengagement of the locking members upon rotation of the disposable assembly with respect to the drive assembly.