Infusion Device Having a Drive Mechanism for Driving a Pusher Device

An infusion device for administering a medical fluid to a patient, comprising:

• a housing having a receptacle for receiving a syringe,
• a pusher device which is movable along a pushing direction for acting onto a piston of a syringe received on the receptacle, and
• a drive mechanism for driving the pusher device, the drive mechanism comprising
• a first drive element,
• a second drive element being in threaded engagement with the first drive element, the second drive element being translationally movable with respect to the first drive element by rotating the first drive element, and
• an electric drive for rotating the first drive element,
• wherein one of the first drive element and the second drive element is a spindle having an outer threading and the other of the first drive element and the second drive element is a spindle nut being in threaded engagement with the outer threading of the spindle,
• wherein the drive mechanism comprises a brake mechanism for rotationally fixing, in a brake state, the second drive element such that a rotation of the first drive element causes a translational movement of the second drive element, and for rotationally releasing, in a release state, the second drive element to allow a rotation of the second drive element with respect to the first drive element while the first drive element is at standstill.