To load a complete copy of Patent 6,137,288 from the USPTO, click
HERE Go To Home Page
Several variations of this rotary position sensor are shown in the picture to the left.  These four parts were sold to TRD and TRD gave them back to me as a personal momento when they were finished with them.   The parts in the picture were designed between 1999 and 2001. 
Click here to view Rotary Angle Sensor Patent 5,444,369
A magnetic flux density plot from
sheet 7 of 14 in this patent.
Click here to view other patents that reference 6,137,288