Patent ID: 8920374

Claim:
An automatic injector adapted to receive a cartridge including a barrel, a needle, and a plunger assembly including a plunger seal, the cartridge defining a longitudinal axis, the injector comprising: a housing, a cartridge carrier adapted to receive at least a portion of the cartridge, the cartridge carrier being disposed for movement relative to the housing in a direction parallel to the longitudinal axis of the cartridge, a plunger carrier disposed for movement relative to the cartridge carrier, the plunger carrier being disposed to confront and impart movement at least a portion of the plunger assembly, at least one transfer instrument disposed to selectively couple the cartridge carrier to the plunger carrier for movement therewith, an elongated drive device coupled to the plunger carrier, the elongated drive device being disposed to provide movement of the plunger carrier in a direction parallel to the longitudinal axis of the cartridge, at least one or the plunger carrier and the cartridge carrier including an opening that selectively receives the at least one transfer instrument to removably couple the cartridge carrier to the plunger carrier, a motor, and a transmission assembly coupling the motor to the elongated drive device.