Auto-Injector Apparatus

An auto-injector apparatus, comprising:

• a housing having a proximal end and a distal end;
• a container carriage reciprocably disposed in the housing, the container carriage including a cavity adapted to receive a medicant container, the container carriage being movable within the housing between first and second carriage positions;
• a roller disposed in the housing and positioned to roll proximally through the cavity of the container carriage to expel medicant from the container;
• and
• a main drive spring operably associated with the carriage to move the carriage proximally from its first position to its second position.

A method of auto-injecting a liquid medicant into a patient, comprising:

• (a) placing a proximal end of an auto-injector apparatus against the patient's body;
• (b) releasing a main drive spring;
• (c) driving a needle proximally within the apparatus with the main drive spring so that the needle extends out of the proximal end of the apparatus, thereby inserting the needle in the patient's body;
• and
• (d) creating relative motion between a pump and a flexible medicant container within the apparatus and thereby forcing the medicant out of the flexible medicant container through the needle into the patient's body.

An auto-injector apparatus, comprising:

• a flexible container containing a liquid medicant;
• a needle communicated with the container;
• a roller positioned to engage the flexible container and expel the medicant from the container upon relative movement in a displacement direction between the roller and the container, the roller having a rotational axis transverse to the displacement direction;
• and
• wherein the flexible container has a width transverse to the displacement direction, the width varying along the displacement direction.