Magnetic detent and position detector for fluid pump motor

Abstract

A medical infusion pump (10) including an improved electric motor assembly (256). The medical infusion pump (10) includes a pumping mechanism (250) and a pump chamber (132) in an operative position with respect to the pumping mechanism (250), the pumping mechanism (250) manipulating the pump chamber (132) to pump liquid through the pump chamber. An electric motor (256) having a rotatable drive shaft (316) is operably linked to the pump driving mechanism (250) and the pump driving mechanism (250) pumps a select amount of liquid through the pump chamber (132) on each rotation of the electric motor drive shaft (316). The improved electric motor assembly (256) includes a motor having a portion of a drive shaft (388) extending therefrom. A magnet (392) is attached to the extending portion of the drive shaft for rotation with the drive shaft. A flux gatherer (396) is spaced from and magnetically coupled to the magnet (392) for biasing the poles of the magnet in a select orientation relative to the flux gatherer (396) so as to stop the pump driving mechanism (250) in a select position. A magnetic position detector (400) is spaced from and magnetically coupled to the magnet (392) for emitting an electrical signal each rotation of the drive shaft (388).

Dependencies are inferred from the claim text.