DR. DAVID W HANSON, M.D.
Osteopathic Medicine at Shea Blvd, Scottsdale, AZ

4902903, Feb 20, 1990

Oct 27, 1988

7/263652

Eugene E. Segerson - Tempe AZ
David L. Vowles - Phoenix AZ
David D. Hanson - Scottsdale AZ

G01N 2186

250561

An improved vehicle height sensor and automotive leveling system are described using, in a preferred embodiment, two optical emitter-receiver pairs mounted in the sidewall or dust cover of a standard automotive air shock. The emitter-receiver pairs are arranged to operate by reflecting light from the central shaft of the shock absorber. Each emitter-receiver pair provides a light path that lies in a plane substantially perpendicular to the extension direction of the shock. The two emitter receiver pairs are spaced apart along the extension direction of the shock. Movement of the internal piston of the shock successively interrupts (by absorption) the light paths of the emitter-receiver pairs so as to provide a positive indication of the location of the movable piston and hence the height of the shock and the height of vehicle body above the road. The emitter-receiver pairs are mounted in a common assembly and seal to the shock dust cover through a single hole. They are convenient to manufacture in a single module which includes the control logic needed to add to remove fluid from the shock to maintain it in reference position independent of the vehicle load.