EP0615762A1 — Dosing seringe

USPTO Abstract

A medication dispensing device (20) comprising a cartridge (24) for containing an injectable product therein and an injector (22) attached to the cartridge. The injector includes a drive mechanism comprising a dosage sleeve (78,81) having a dosage knob (88) at the proximal end thereof and a threaded rod (72) coupled to the sleeve and axially advanceable into the cartridge upon clockwise rotation of the knob for dialing up a desired dosage to be injected. A ratchet mechanism (150) is disposed in the injector housing and includes a rotatable piece (152) secured to the dosage sleeve for rotation therewith and a locking seat (168) in engagement with the rotatable piece. The ratchet mechanism permits rotational movement of the sleeve (78) in the clockwise direction only. A disengaging mechanism (200) is secured to the housing of the LCD assembly (70) and includes a pin (206) that extends into and engages the rotatable piece (152) of the ratchet mechanism such that axial movement of the pin causes corresponding axial movement of the stationary piece. Upon depressing the outer surface (204) of the disengaging mechanism, the pin and the rotatable piece are moved axially away from the seat sufficiently enough to permit a user to rotate the dosage knob (88) in a counterclockwise direction to accurately dial back an accidental overdose measurement without removing the cartridge from the injector.