Self-injection device

A method, comprising

• providing a body of a medicament delivery device;
• providing a reservoir in the body, the reservoir having a movable portion;
• and
• providing a plurality of plungers, each plunger having at least one axially extending member with and engaging structure thereon, the engaging portion being engagable with one of the body and a plate within the body, a length of the at least one axially extending member of a plunger differing from the length of the axially extending member of at least one of the remaining plungers, and each plunger corresponding to a reduction of fillable volume of the reservoir to one of a number of predetermined volumes.

A method, comprising:

• providing a body of a medicament delivery device;
• providing a reservoir in the body, the reservoir having a movable portion;
• and
• providing a plurality of plungers, each plunger having at least one axially extending member with an engaging means thereon, the engaging means being engagable with one of the body and a plate within the body, a length of the at least one axially extending member of a plunger differing from the length of the axially extending member of at least one of the remaining plungers, and each plunger corresponding to a reduction of fillable volume of the reservoir to one of a series of predetermined volumes.

A method, comprising:

• providing a body of a medicament delivery device;
• providing a reservoir in the body, the reservoir having a movable portion;
• providing a pressurization system comprising a pressurization spring and a plunger, the plunger having an engaging structure for retaining the plunger against a force of the pressurization spring in an initial position contacting and compressing the reservoir;
• and
• changing the initial position of the plunger relative to the movable portion to provide to a desired fillable volume.

A method, comprising:

• providing a body of a medicament delivery device;
• providing a reservoir in the body, the reservoir having a movable portion;
• providing a pressurization system comprising a pressurization spring and a plunger, the plunger having an engaging structure for retaining the plunger against a force of the pressurization spring in an initial position contacting and compressing the reservoir;
• and
• changing the amount of compression of the spring to correspond to a desired fillable volume.