Inclined plate 360 degree absolute angle sensor

• US 5,887,351 A
• Filed: 01/13/1997
• Issued: 03/30/1999
• Est. Priority Date: 01/13/1997
• Status: Expired due to Term

• Current Assignee: Lord Corporation (Parker-Hannifin Corporation)
• Original Assignee: MicroStrain, Inc. (Spectris PLC)
• Inventors: Arms, Steven W., Townsend, Christopher P., Mundell, Steven W.
• Primary Examiner(s): BENNETT, GEORGE B
• Application Number:
  US08/782,393
• Time in Patent Office: 806 Days
• Field of Search: 33/1 N, 33/1 PT, 33/511, 33/512, 33/534, 33/465, 33/471, 33/504, 33/784, 33/366
• US Class Current: 33/1.0PT
• CPC Class Codes: G01B 7/30 for measuring angles or tapers; for testing the alignment of axes

Abstract

The novel inclined plate 360 degree absolute angle sensor is designed to measure the absolute angle created by a base and a rotating surface. The assembly contains a metal inclined plate positioned above four coils so that coils one and two are at the minimum and maximum distance from the plate respectively, while at the same time, coils three and four are equidistant from the inclined plate. Rotation of the plate around a centerline, changes the distance that all four coils with respect to the inclined plate which, in turn, creates a change of the inductance of the coils. This change in inductance may be measured with alternating current bridge technologies in order to provide a measure of absolute angular position of a rotating surface with respect to the base.

Claims

1. An inclined plate 360 degree absolute angle sensor, for use in medical, industrial, commercial and personal applications to measure a relative or rotational angle, comprising:

a housing;

said housing having a base;

said base having at least one non contacting sensor;

said housing further having a rotating surface;

said rotating surface comprising an inclined plate with the relative rotation of said inclined plate and said non contacting sensor causing the distance between said inclined plate and said non contacting sensor to be varied; and

said housing further having signal sending means from said sensor.

2. An inclined plate 360 degree absolute angle sensor, according to claim 1, wherein:

said base of said housing comprises a primary arm unit; and

said rotating surface of said housing comprises a secondary arm unit.

3. An inclined plate 360 degree absolute angle sensor, according to claim 2, wherein:

said arms units having a reference point a distance "L" from the vertex whereby an analyzing unit can calculate the distance "D" between the reference points on said primary and said secondary arm units.

4. An inclined plate 360 degree absolute angle sensor, according to claims 1, wherein:

said housing comprises a unit of rigid construction;

said unit of rigid construction comprises a transparent material; and

said unit of rigid construction further comprises an opaque material with a transparent viewing means.

5. An inclined plate 360 degree absolute angle sensor, according to claim 2, wherein:

said primary arms unit having slot receiving means for allowing passage of said secondary of said arm unit to pass in close proximately thereby and allow said second of said arm unit to move in a complete three hundred and sixty degree rotation.

6. An inclined plate 360 degree absolute angle sensor, according to claim 2, wherein:

said sensor comprises inductive means;

said inductive means comprises a plurality of coils positioned equidistant apart and mounted within said primary of said arm units;

said sensor comprises capacitive means; and

said capacitive means comprises a plurality of printed electrodes positioned equidistant apart and mounted within said primary of said arm units.

7. An inclined plate 360 degree absolute angle sensor, according to claim 2, wherein:

said inclined plate comprises targeting means positioned within a recess within said secondary arm unit;

said inclined plate having a rotating cuff housing positioned within said recess within said secondary arm unit and attached thereto; and

said inclined plate further having a restraining ring positioned over said rotating cuff housing and attached to said primary arm unit.

8. An inclined plate 360 degree absolute angle sensor, according to claim 7, wherein:

said inclined plate comprising a unit of conductive material; and

said inclined plate comprising a unit of ferrous material.