Eldec Corporation

Ted M Daniels

Bernard J Burreson

William R Little

A variable reluctance saturable core proximity sensor assembly comprising a target and a sensor. The target consists of a magnet having a high field strength, a base plate having a high relative permeability, and a nonmagnetic metal housing surrounding the magnet and base plate. The sensor consists of a core made from a material having a high relative permeability, a coil surrounding the core and a housing made from a nonmagnetic material surrounding the core and coil. At its distal end of the core is a flux director that intercepts the magnetic field produced by the target. The flux director comprises a plurality of radially extending arms having the same permeability as the core. The flux director has a cross-sectional area selected so that the flux director and core saturate at substantially the same time. The sensor assembly may be used in either a slide-by or head-on mode.

Saturable core proximity sensor including a flux director and a magnetic

A fiber optic sensor for determining the position of a shaft 10 that is supported by a bearing 12 includes a sensor circuit 14 and at least one fiber 16 that extends from the sensor circuit to a point proximate but slightly separated from the shaft surface, with a portion of the optical fiber extending through and being carried by the bearing. Target areas 18, 20 and 22 are located on shaft 10 so as to correspond to the positions to be determined. Each target area consists of an angled recess that is constructed and arranged, relative to the numerical aperture and orientation of the optical fiber, so as to substantially nonreflective insofar as the optical fiber is concerned, thus providing a sharp contrast to the highly reflective background of the shaft surface.

Fiber optic position sensor

Fluid under pressure is routed through an input port to a bore provided within a housing. A piston is disposed within the housing for movement within the bore. A target member includes a piston portion which frictionally engages, and is received within, the wall of a bore provided in the piston, causing the piston and target to move as a unit. A proximity sensor mounts to the housing in a location to switch to its activated state in response to displacement of the target member to a position corresponding to a predetermined fluid pressure level. Spring packs, exhibiting a predetermined wear characteristic, resiliently bias the piston to resist displacement due to applied fluid pressure. Compensation for spring pack wear and bearing contact wear is automatically provided by increased penetration of the target member piston portion into the piston bore upon application of a fluid pressure substantially in excess of the switching level, whereby the proximity sensor is activated at a set fluid pressure level substantially independent of spring pack system wear.

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Edmonds, WA, United States of America

Ted M Daniels