US Patent 6971143 Magnetic detent for rotatable knob

A roller pump including a stator and a rotor assembly disposed within the stator. The rotor assembly includes a rotor hub, a first roller slide and a second roller slide slidingly disposed within the rotor hub. Each of the roller slides rotatably supports a roller. An occlusion adjustment knob for adjusting a radial position of the first and second roller slides and a magnetic detent assembly for providing an audible indicator as the occlusion adjustment knob is rotated.