EP0498737A1 — Dosing means for an injector

USPTO Abstract

A cartridge 4 is loaded into and unloaded from a cylindrical main body by a attaching/detaching member so that a piston 5 of the cartridge 4 can be pushed by a plunger 9. The plunger 9 is movable in a direction (direction D) to push the piston 5. Since the plunger 9 is locked with a return preventive member 7 which prohibits its reverse movement, it does not move backward. A pair of jaws 12, which are biased to be set in locked and unlocked states with and from a locking portion 9a of the plunger 9, are held by a jaw holder 13 so that the locked state can be set by a sleeve 10. The sleeve 10 is operated to unlock the jaws 12, and a setting dial 17 of a setting member is operated to set the shift amount of the jaw holder 13 in the longitudinal direction. The shift amount is displayed by a display member 16. A push member 20 for pushing the piston 5 is provided with a jaw holder 13 to be integrally movable with it in the longitudinal direction, and is moved by a biasing member 22 to move the jaw holder 13 toward the display member 16.