Randy D Porter

US Patent:

54463769, Aug 29, 1995

Filed:

Oct 22, 1993

Appl. No.:

8/139675

Inventors:

Randy D. Porter - Greene NY
Matthew W. Pankow - Buffalo NY

Assignee:

The Raymond Corporation - Greene NY

International Classification:

G01P 352
G01P 1300
G08B 2100

US Classification:

324165

Abstract:

The present invention features a method and an apparatus for sensing the speed and the direction of rotation of a motor. The apparatus of the invention has a timing wheel disk that is attached to the rotational shaft of a motor and has a number of slots. Opposite the timing wheel are mounted two spaced-together proximity sensors that are a given or a fixed distance apart. The sensors are spaced to read within each slot of the disk at any given point during in the rotation of the timing wheel. When the sensors detect the edges of each slot of the rotating wheel, signals are generated. The sensors respectively define sensing channels A and B. A microcontroller contains a logic program that calculates the motor's speed and direction. Speed is determined by measuring the time that it takes for a point (the edge of a rotating disk's slot) to travel across both sensors. Direction is determined by storing the logic level of the first sensor (channel A) while a generated exclusive OR signal is high, and then analyzing the level of channel A when the exclusive OR is low.