MULTI-CARTRIDGE MEDICATION INJECTION DEVICE

摘要

A multi-cartridge dispenser (40) for delivering two liquid medications through a single needle (41). The dispenser includes independent dual channel metering mechanisms (58), dual channel drive mechanisms (68, 88, 118, 132), and dual channel lock and pullback mechanisms (138, 148). The wing (132) must be in its "up" position for metering to take place. The wing reciprocatingly moves a driver (118) between a pre-injection position and a post-injection position to reciprocatingly advance the leadscrews (118) upon an injection stroke. The dosage indicator (66) automatically rotates to its initial zero position upon the injection stroke. The lock and pullback mechanism automatically prevents rotation of the leadscrew upon metering and injection. It also locks out the cartridge retainers (188) so that the retainers can be removed from the housing (42) only while the wing is in its "down" position. The pullback sleeve (148) unloads a pullback key (138) during a cartridge (184) change in order to enable the leadscrew to be spun freely back to its home position.