Caterpillar Inc.

Timothy A Boston

John W Crayton

Bruce E Unger

Paul C Gottshall

David A Betts

Noel J Rytter

Rolland D Scholl

Kevin Dee Ehrenhardt

Darrel W Berglund

Lonnie D Atteberry

Jeffrey J Riebschlager

Zachary A Kauk

Lisa A Creger

A sensor for detecting particles in a fluid including a housing having a cavity associated therewith, a magnet disposed adjacent the cavity to attract particles into the cavity, first and second coils wound around the outer surface of the cavity, the induction of the first coil being responsive to the particle accumulation within the cavity, the inductance of the second coil being responsive to the temperature of the fluid and being independent of the particle accumulation within the cavity, a first microprocessor coupled to the first and second coils for processing the signals received therefrom and for outputting signals indicative of the particle accumulation within the cavity, an rf transmitter for converting the signals received from the first microprocessor into rf signals, and an rf antenna for transmitting the processed signals to a remote location. The signals outputted from the first microprocessor are encoded with an identification code to identify and distinguish such signals. A second rf antenna and receiver are positioned at a remote location for receiving the transmitted rf signals. The receiver decodes and processes such transmitted rf signals back into an electrical signal indicative of the particle accumulation within the cavity and inputs such signal into a second microprocessor or electronic controller which stores and monitors such information for diagnostic, prognostic and trend analysis purposes.

Fluid particle sensor apparatus and method for transmitting data to a remote receiver

A sensor apparatus for detecting both ferrous and non-ferrous particles in a fluid including a housing adapted for insertion into a fluid line, the housing having a collection cavity formed therewithin for trapping and holding metallic particles which are suspended in the fluid as the fluid passes through the sensor. A first coil wound below the collection cavity and a second coil wound about the collection cavity, the inductance of the first coil being responsive to the temperature of the fluid passing through the sensor and the inductance of the second coil being responsive to the ferrous and non-ferrous particle accumulation within the collection cavity. An electromagnetic coil is spaced above the second coil to attract ferrous particles away from the vicinity of the second coil. Based upon eddy current principles and because eddy currents are a function of material conductivity, a first energization of the second coil generates a signal indicative of the total ferrous and non-ferrous particle accumulation within the collection cavity and a second energization of the second coil with the electromagnetic coil likewise energized generates a signal indicative of just the non-ferrous particle accumulation within the collection cavity. A microprocessor coupled to the coils calculates the percentage of ferrous and non-ferrous particles in the collection cavity and outputs such information for diagnostic, prognostic and trend analysis purposes.

Fluid particle sensor apparatus and method for detecting ferrous and non-ferrous metals

An inductive spool displacement sensor for determining the position or displacement of a spool within a particular hydraulic valve including a sensor housing having a cavity formed therein adapted for mounting within the hydraulic valve, the sensor housing being positioned such that at least a portion of the valve spool is disposed to enter the sensor cavity during certain operations of the valve. The sensor further includes a sensing coil wound about the housing cavity and a reference coil wound about the housing and spaced from the sensing coil, the inductance of the sensing coil being responsive to movement of the spool within the cavity and the inductance of the reference coil being responsive to the temperature of the fluid passing through the hydraulic valve. Based upon eddy current principles and because eddy currents are a function of material conductivity, the sensing coil, when energized, generates a signal indicative of that portion of the spool present within the housing cavity. Electronic circuitry, including a microprocessor, are coupled to the coils for receiving signals therefrom, the microprocessor determining the position of the spool relative to the cavity, or some other predetermined reference point, and outputting a signal proportional to the position or displacement of the spool within the hydraulic valve. The reference coil is provided to compensate for changing inductance values due to changing fluid temperature.

Inductive spool displacement sensor

An apparatus is provided for sensing an angular position of a shaft or other rotatable body. The apparatus preferably includes a first and second housing portion. A circuit connected to a circuit board is housed in the housing and includes a plurality of proximity sensors. A rotatable member is rotatably attached to the circuit board and includes a position indicator. The circuit produces a signal as a function of the position of the rotatable member.

Angular position sensor having no physical electrical contact between a

An apparatus for sensing the level of fluid, including a two electrode device being disposed in the fluid and a microprocessor. The microprocessor being connected to the two electrode device and delivering alternating current thereto. The microprocessor reads the voltage across the device, compares the voltage to a predetermined voltage level, and produces a warning signal in response to the fluid level being below a predetermined fluid level.

Fluid level sensing apparatus

In one aspect of the present invention, a sensor detects particles within a fluid. The sensor includes a housing that defines a cavity. A magnet is disposed adjacent the cavity bottom to attract particles into the cavity. A first coil is wound about the outer surface of the cavity. The induction of the first coil is responsive to the particle accumulation within the cavity. A second coil is wound about the magnet. The induction of the second coil is responsive to the temperature of the fluid and independent to the particle accumulation within the cavity.

Fluid particle sensor including a container, a first coil and a second

In one aspect of the present invention, an apparatus for measuring the height of liquid contained in a storage tank is disclosed. A tube is disposed inside the tank. A float is disposed inside the tube and is buoyed on the surface of the liquid. An ultrasonic transducer is disposed inside the tube. The ultrasonic transducer emits ultrasonic pulses toward the float, receives the reflected ultrasonic pulses, and responsively produces an echo signal. The float has a top portion and a bottom portion separated by a cylindrical portion. The bottom portion including an spherical surface which receives the ultrasonic pulses. The spherical surface has a predetermined radius which is a function of the inside diameter of the tube, the height of the cylindrical portion of the float and the outside diameter of the cylindrical portion of the float. A temperature sensor monitors the temperature of the liquid and produces a thermometric signal in response to the liquid temperature. A microprocessor receives the echo and thermometric signals, determines the speed of the ultrasonic pulse traveling in the liquid, and responsively determines the liquid height.

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Tremont, IL, United States of America

Timothy A Boston