Patent ID: 8444607

Claim:
A delivery device for delivering an infusion medium to a user, the device comprising: first and second housing portions adapted to be carried by a user and configured to be selectively engaged together for operation and selectively separated from each other; a reservoir supported by the first housing portion, the reservoir including a reservoir housing having an axis extending along an axial dimension of the reservoir and an interior defining a volume, a plunger head moveable relative to the reservoir housing along the axial dimension within the reservoir interior to selectively change the volume of the reservoir interior, and a plunger shaft extending from the plunger head to a position outside of the reservoir housing, the plunger shaft being fixed to the plunger head when the first and second housing portions are engaged together and when the first and second housing portions are separated from each other; a rotatable lead shaft supported by the second housing portion for rotation about the axis of the reservoir when the first and second housing portions are engaged; a nut member having an open side, the nut member being supported in a fixed relation with the plunger shaft of the reservoir for movement along the axis of the reservoir with movement of the plunger head along the axial dimension, the nut member being fixed to the plunger shaft when the first and second housing portions are engaged together and when the first and second housing portions are separated from each other, the nut member having a structure for engaging the rotatable lead shaft in any one of a plurality of positions along the axis of the reservoir; the rotatable lead shaft being supported by the second housing portion in a position to be inserted in a direction transverse to the axis of the reservoir through the open side of the nut member to threadably engage with the nut member, as the first and second housing portions are brought together for operative engagement, the rotatable lead shaft being rotatable when threadably engaged with the nut member, to move the nut member relative to and along the length of the rotatable lead shaft with rotation of the lead shaft.