Infusion pump

A drive mechanism for an infusion pump, the drive mechanism adapted to linearly move a syringe plunger within a syringe barrel supported by the pump, the mechanism comprising:

• a motor;
• a lead screw rotatably connected to the motor;
• a slide assembly having a threaded member supported thereon, the threaded member including first and second threaded portions of a rotary nut coupled to threads of the lead screw;
• an arm having one end connected to the slide assembly and one end adapted to be engaged with the syringe plunger;
• the threaded member being in biased engagement with the lead screw, wherein upon rotation of the lead screw by the motor, the slide assembly linearly moves the arm wherein the arm is adapted to move the syringe plunger within the syringe barrel;
• and
• a disengagement rod pivotable to linearly move and engage and rotate the rotary nut to a disengaged position, wherein the threaded portions are not in engagement with the lead screw.