Abstract: The present invention provides a pressure sensing device for sensing pressure which is adapted to provide an electrical indication of a sensed pressure. The pressure sensing device has a top lamination, a middle lamination, and a bottom lamination. A pressure sensor is located within an aperture defined in the middle lamination. First and a second electrical connectors, being exposed by the aperture, make electrical connection with the pressure sensor when pressure or compression is applied to the pressure sensing device. An output electrical signal indicative of the applied pressure is produced when the pressure sensor has electrical contact with the electrical conductors.

Abstract: An electromagnetic actuator for an electromagnetically actuated valve is disclosed. The actuator includes an electromagnet and an armature, the armature having a normally biased initial spaced apart first position distal from the electromagnet when the electromagnet is off and a second fixed stop position in abutment with the electromagnet when the electromagnet is on. In addition, the actuator includes a resilient member adapted to bias the armature in the normally biased initial spaced apart first position, and a compliant member operably connected to the armature. The armature approaches the electromagnet when the electromagnet is on and compresses the compliant member until the armature reaches the fixed stop position.

Abstract: The present invention is directed towards an electronic valve having a filter for filtering particulate matter from a fluid. The apparatus comprises a solenoid coil, an armature slidably disposed for limited axial sliding movement in response to current passing through the solenoid coil, a stator fixed relative to the solenoid coil, a bore extending toward the armature, a pin slidably disposed in the bore, a cage defining a cage aperture, and an edge filter disposed within the cage aperture.

Abstract: In one aspect of the present invention, an automatic screed temperature control is disclosed. The control senses the screed temperature and compares the screed temperature to a lower set point. In response to the screed temperature being less than the lower set point, the control causes fuel to dispense into the combustion chamber and subsequently causes the fuel to ignite in order to heat the screed. The screed is heated until the screed temperature becomes greater than an upper set point.

Abstract: An apparatus for controlling the load of an engine associated with a hydrostatic drive system is disclosed. The apparatus includes a variable displacement pump rotatably driven by the engine. The apparatus modifies a pump displacement command signal in response to the actual and desired engine speed acceleration. The modified pump displacement command signal is used to control the displacement of a variable pump in order to regulate the load on the engine to achieve optimum efficiency.

Abstract: An armature assembly is provided for use in a solenoid actuator assembly having an energizable coil. The solenoid actuator assembly includes a housing and a bore disposed in the housing. The armature assembly has an outer surface and is positioned in the bore for axial sliding movement. The armature assembly has an outer surface which is of a diameter significantly less than a diameter of the bore and defines a fluid passage through the bore. Sleeve bearings are positioned at preselected spaced locations within the bore and extends about and in contact with a shaft of the armature assembly.

Abstract: A control system for lubricating a work machine is provided. The control system includes a lubricant distribution system, a charging system adapted to drive the lubricant distribution system, a sensor for determining the operating state of the charging system, and a device for calculating a time interval being dependent upon a previous lubricating event. The control also includes a device for producing a lubrication signal in response to the time interval reaching a predetermined interval constant.

Abstract: An apparatus for communicating with an electronic control module on an engine of a machine from a remote location is disclosed. The apparatus includes an electronic controller associated with a power supply on the electronic control module. A sensor is connected to the electronic controller for sensing an engine parameter indicative of the operating state of the engine. A communications interface for transmitting and receiving a communication signal is associated with the electronic controller. An ignition switch is connected to the power supply, such that when the ignition switch is in the off position, the electronic controller is powered down. The electronic controller is subsequently powered up if a communication signal is received from the remote location.

Abstract: An apparatus for improving the power dissipation of a semiconductor device surface mounted on a printed circuit board having at least a top printed circuit board layer and a bottom printed circuit board layer is provided. The apparatus includes a first pad of metallic material connected to a top surface of the top printed circuit board layer. The semiconductor device is connected to the first pad. A second pad of metallic material is connected a to the top surface of at least one of the top and bottom printed circuit board layers, wherein the second pad is electrically isolated from the semiconductor device. The apparatus also includes at least one thermal via for heat transfer through the printed circuit board layers thermally coupled to the thermal pad. A heat sink is thermally coupled to the at least one thermal via.

Abstract: An electromagnetic actuator is disclosed. The actuator includes a core having an inner and outer pole that defines a pole face. A coil of windings is disposed in the core and produces a magnetic field. An armature is moveable between first and second positions in response to the force produced by the magnetic field. A stroke elongation device is disposed adjacent to the outer pole piece and closely spaced from the armature. The stroke elongation device increases the pull-in force of the electromagnetic actuator.

Abstract: In one aspect of the present invention, an apparatus for detecting particles within a fluid is disclosed. A bobbin defines a debris collection chamber. Spaced apart first and second coils are wound about the bobbin in the proximity of the debris collection chamber, wherein the inductance of the coils are responsive to the particle accumulation within the collection chamber. An electromagnet is wound about the second coil to attract ferrous particles into the proximity of the second coil. A reference coil is wound about the bobbin to compensate for the changing temperature of the fluid. An oscillator is coupled to the first, second and reference coils for selectively producing an oscillating waveform at a frequency that induces eddy currents in the particles. The frequency of the oscillating waveform is indicative of the amount of accumulation of both the ferrous and non-ferrous particles.

Abstract: In one aspect of the present invention, an apparatus for detecting particles within a fluid is disclosed. A bobbin defines a debris collection chamber. A first coil is wound in a helix about the bobbin in the proximity of the debris collection chamber, wherein the induction of the first coil is responsive to the particle accumulation within the collection chamber. A reference coil is wound in a helix about the bobbin to compensate for changing fluid temperature. An oscillator is coupled to the first and reference coils for selectively energizing the coils with an oscillating waveform at a frequency that induces eddy currents in the particles. The frequency of the oscillating waveform is indicative of the amount of accumulation of both the ferrous and nonferrous particles.

Abstract: In one aspect of the present invention, an automatic screed temperature control is disclosed. The control senses the screed temperature and compares the screed temperature to a lower set point. In response to the screed temperature being less than the lower set point, the control causes fuel to dispense into the combustion chamber and subsequently causes the fuel to ignite in order to heat the screed. The screed is heated until the screed temperature becomes greater than an upper set point.

Abstract: An apparatus for controlling a material feed system of a paver is disclosed. The material feed system includes a feeder conveyor and a spreader auger. The apparatus includes a sensor that monitors the amount of material at the edge of the screed and responsively produces an actual material height signal. A rotary switch produces a desired material height signal indicative of a desired amount of material at the edge of the screed. A controller receives the actual and desired material height signals, determines a desired rotational speed of the auger in response to the difference between the signal magnitudes, and produces a command signal to rotate the auger at the desired speed. An electrohydraulic system receives the command signal and rotates the auger at the desired rotational speed.

Abstract: An apparatus for controlling the load of an engine associated with an hydrostatic drive system is disclosed. The apparatus modifies a pump displacement command signal in response to the actual and desired engine acceleration. The modified pump displacement command signal is used to control the displacement of a variable pump in order to regulate the load on the engine to achieve optimum efficiency.

Abstract: In one aspect of the present invention, a control system for a floating screed assembly for an asphalt paving machine is disclosed. The screed assembly includes a main screed and extension screed unit. An electrohydraulic device extends and retracts, as well as, raises and lowers the extension screed unit relative to the main screed unit. The electrohydraulic device additionally pivots the extension screed unit relative to the main screed unit about a horizontal axis. Position sensors produce position signals in response to the position of the extension screed unit. A controller receives the position signals and produces command signals to control the extending, retracting, and pivoting of the extension screed unit to a desired position.

Abstract: An apparatus is provided for indicating a fault condition in a machine having a plurality of parameters each having levels being dependent upon machine performance. The apparatus includes a sensor adapted to produce an electrical signal in response to the level of one of the of parameters; and a processor for identifying a trend in the parameter level in response to the electrical signal, calculating the duration and slope of the trend; and determining whether a first warning threshold is exceeded in response to the duration and slope of the trend, the first warning threshold being a function of duration and slope.

Abstract: A driver circuit for controllably connecting an inductive load to a source of electrical power in response to an input control signal is provided. The inductive load includes an inductive winding of a solenoid. The driver circuit controllably connects and disconnects the inductive load to and from the source in response to a first control signal and controllably provides a discharge path for a flyback current of the inductive load in response to a second control signal. The driver circuit senses both the energizing current and the flyback current and responsively provides an energization path and a flyback discharge path in a non-overlapping manner.

Abstract: In one aspect of the invention, an apparatus for sensing a plurality of operating parameters of an internal combustion engine is disclosed. An energy source supplies electrical energy to the pistons, whereby each piston forms a variable capacitor with the engine housing. The capacitance value of each variable capacitor changes as a function of the relative position of the piston to the housing. An oscillator circuit produces a capacitive signal that is indicative of the capacitance value of each variable capacitor. A microprocessor receives the capacitive signal and responsively determines one of a plurality of operating parameters of the engine.