Chrysler Corporation

Hi-stat Manufacturing Company, Inc.

Robert W Eshelman

Frederick W Crall

Robert P Benjey

A speed and distance sensor comprises a circular magnet supported on a shaft journaled on a housing. The magnet is polarized at regular circumferential intervals and is accurately axially located within the housing. A reed switch is disposed adjacent the rotating magnet and is coupled with the varying magnetic field produced by the rotating magnet so that the reeds open and close as the magnet rotates. The reed switch is mounted within the housing on a retainer, and the retainer is selectively positionable via an adjustment screw for precisely positioning the reed switch in relation to the magnet to achieve a degree of coupling which produces a desired duty cycle characteristic in the opening and closing of the reed switch. A wiring harness is connected with the leads of the reed switch to provide for connection with an external electronic circuit. The wires and leads are accurately located by means of locators formed in the housing to promote convenient assembly. In another embodiment the reed switch mounts on the housing by means of its own lead wires, and a compensator on the housing is operable to control the amount of flux from the magnet which acts on the reed switch.

Speed and distance sensor

A pressure transducer comprises a bellows as the pressure sensing element and a variable inductance coil whose inductance is made to vary as a function of pressure sensed by the bellows. Motion is transmitted between the bellows and a plunger associated with the coil by means of a bent lever mechanism. The mechanical advantage of the bent lever is adjustable, after assembly of the transducer, to set the span to a desired value.

Pressure transducer

A pressure transducer comprises a series-connected helical coil spring and bellows assembled into the bore of a housing by anchoring the spring and bellows at locations which place them in a state of tension. Expansion and contraction of the bellows reacts against the spring and correspondingly positions a ferrite slug within an inductance coil to cause the inductance thereof to be a function of the pressure differential acting on the bellows. One end of the coil spring is threaded onto a threaded fitting secured to one end of the bellows, and slope calibration of the transducer is accomplished by setting the amount of engagement of the spring with the threaded fitting. Offset calibration can be performed by either of two disclosed techniques, and the offset and slope calibrations can be independently made.

Growing community of inventors

Ann Arbor, MI, United States of America

Robert W Eshelman