Metering injector for delivering liquid, and method of using same

An injector for delivering medicament, the injector comprising:

• a body having a proximal end, an opposing distal end, a longitudinal axis extending therebetween, and a track follower adjacent to the proximal end, track follower being a projection that extends at least slightly inwardly from an interior surface of the body;
• a plunger disposed at least partially within the body and movable with respect to the body along the longitudinal axis;
• an actuator positioned at the proximal end of the body and operably connected to the plunger, the actuator comprising a track configured to receive at least a portion of the track follower therein, the track comprising a first portion and a second portion, the first portion limiting travel of the actuator along the longitudinal axis to deliver a first predetermined amount of the medicament the second portion limiting travel of the actuator along the longitudinal axis to deliver a second predetermined amount of the medicament, the first predetermined amount being different than the second predetermined amount, the actuator being positionable to selectively control displacement of the plunger pursuant to the first portion or the second portion of the track;
• and
• a directionally limited sliding arrangement between the actuator and the plunger, wherein when the actuator is pulled outward to prepare for a dose being administered, the actuator is able to slide along the plunger without causing the plunger to be withdrawn or moved away from a piston, while when the actuator is pressed inward to deliver the dose, the plunger is fixed to the actuator such that movement of the actuator drives the plunger forward,
• wherein the track further comprises a third portion extending between the first and second portions, the third portion extending at least substantially perpendicularly to the first and second portions.

An injector for delivering liquid, the injector comprising:

• a body having a proximal end, an opposing distal end, a longitudinal axis extending therebetween, and a track follower adjacent to the proximal end;
• a plunger disposed at least partially within the body and movable with respect to the body along the longitudinal axis;
• an actuator positioned at the proximal end of the body and operably connected to the plunger, the actuator comprising a track including a first portion, a second portion, and a third portion, the first portion being spaced-apart from the second portion, the first portion extending at least substantially parallel to the second portion and the longitudinal axis, the third portion extending at least substantially perpendicularly to the first portion, the first portion limiting travel of the actuator along the longitudinal axis to deliver a first predetermined amount of the liquid, the second portion limiting travel of the actuator along the longitudinal axis to deliver a second predetermined amount of the liquid, the first predetermined amount being different than the second predetermined amount, the actuator being positionable to selectively control displacement of the plunger pursuant to the first portion or the second portion of the track, the actuator being rotatable in a first direction to align the track follower with the first portion of the track, the actuator being rotatable in a second direction to align the track follower with the second portion of the track, the first direction being opposite to the second direction;
• and
• a directionally limited sliding arrangement between the actuator and the plunger, wherein when the actuator is pulled outward to prepare for a dose being administered, the actuator is able to slide along the plunger without causing the plunger to be withdrawn or moved away from a piston, while when the actuator is pressed inward to deliver the dose, the plunger is fixed to the actuator such that movement of the actuator drives the plunger forward.