DRUG INJECTION DEVICE WITH CARTRIDGE HOLDER AUTOMATICALLY OPERATING CLUTCH ALLOWING RESET OF DRIVE MECHANISM AND DRIVE SPRING RE-LOADING UPON CARTRIDGE EXCHANGE

摘要

Injection device for setting and dispensing of a dose of a medicament from a replaceable drug cartridge, the device comprising: - an elongated main housing (11) accommodating the cartridge (6) filled with the medicament and defining an axial direction (3, 4), - a piston rod (130) arranged inside the main housing (11) and extending in axial direction along a first axis (3) to operably engage with a piston of the cartridge (6), - a drive sleeve (100) rotationally coupled to the piston rod and rotationally biased by a torsion drive spring (126), - a reset member (40) axially displaceable inside the main housing (11) between a proximal operating position (O) and a distal reset position (R) along a second axis (4) radially offset from and parallel to the first axis (4) to switch the device between a reset mode and an operating mode, - a cartridge holder (140) releasably attachable to a distal end of the main housing (11) via a bayonet type coupling along the first axis (3), wherein the cartridge holder (140) comprises a sidewall portion (147) with a radially outwardly protruding lock member (144) to axially engage with and shift the reset member (40) located radially adjacent the cartridge holder (140), the reset member thus forming part of a clutch which together with a ratchet member (60), a dispensing member (30), the drive sleeve (100) and a dose dial (20/32) allows the drive mechanism to be reset and the torsion drive spring to be manually re-loaded after an empty drug cartridge has been removed from the device.