Patent ID: 9220845
Filing Date: 2015-12-29
Classification: A61B,A61M,G01D

Abstract:
1. A medication injector apparatus comprising: a housing; a medicine-filled container mounted to said housing and including a movable piston at one end and an outlet at the other end; a drive member advanceable within said housing in a distal direction to move said piston toward said outlet for forcing medicine from said container; a drive sleeve around and operatively connected to said drive member, said drive sleeve rotatable to advance said drive member distally; a barrel around said drive sleeve and movable in said distal direction within said housing by engagement with said drive sleeve from a first axial position to a second axial position, said barrel being freely rotatable relative to said housing at said first axial position and rotatably fixed relative to said housing at said second axial position; a dose setting element including a manually rotatable portion external to said housing, said dose setting element keyed with said barrel within said housing to be axially movable and rotatably fixed relative to said barrel, said dose setting element in threaded engagement with said drive sleeve; said manually rotatable portion being rotatable in a first direction such that said dose setting element rotates and moves proximally along said drive sleeve due to the threaded engagement therebetween, whereby said dose setting element moves from a plunged position to a plungeable position at which said dose setting element projects farther proximally from said housing than at said plunged position; and whereby when said dose setting element is in said plungeable position, application of a force in a distal direction on said dose setting element first translates distally and without rotation said dose setting element and said drive sleeve and said barrel relative to said housing until said barrel shifts from said first axial position to said second axial position, and then, until said dose setting element reaches said plunged position, translates distally and without rotation said dose setting element relative to said housing while thereby rotating without translation said drive sleeve to advance said drive member distally within said housing.