Patents Represented by Attorney, Agent or Law Firm David M. Masterson
  • Patent number: 5586538
    Abstract: In one aspect of the present invention, a method for correcting an engine map for use in an electronic control system that regulates the quantity of fuel that a hydraulically-actuated injector dispenses into an engine. The engine map stores a plurality of engine operating curves. The method modifies at least one of the engine operating curves in response to the engine temperature, which is indicative of the temperature of the actuating fluid used to hydraulically actuate the injector. Consequently, the engine map curves are corrected to compensate for changing engine temperatures to insure that the hydraulically-actuated fuel injectors dispense a desired quantity of fuel.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: December 24, 1996
    Assignee: Caterpillar Inc.
    Inventor: Travis E. Barnes
  • Patent number: 5580332
    Abstract: The present invention is directed toward determining when a clutch of an automatic transmission substantially fills with fluid. Once it is accurately determined when a clutch fills with fluid, then control over the transmission shifting may reliably be performed. The present invention determines when an on-coming speed clutch substantially fills with fluid in response to determining when an off-going speed clutch releases. Further, the present invention determines when an on-coming direction clutch substantially fills with fluid in response to determining when the torque converter output torque suddenly changes.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: December 3, 1996
    Assignee: Caterpillar Inc.
    Inventors: Randall M. Mitchell, Todd D. Creger, James R. Talbott, Gregory L. Williamson, Richard B. League
  • Patent number: 5578904
    Abstract: An apparatus for determining the position of an armature of an electromagnetic actuator having a coil, the armature being movable to and between first and second positions in response to a current flowing in the coil. The apparatus includes circuitry for measuring the magnitude of current in the coil and producing a magnitude signal, measuring the rate of change of current in the coil and producing a rate of change signal, and measuring the derivative of flux linkage versus current in the coil in response to the rate of change signal and producing a flux linkage signal. The apparatus additionally includes circuitry for determining the position of the armature with respect to the coil in response to the magnitude and flux linkage signals.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 26, 1996
    Assignee: Caterpillar Inc.
    Inventors: Tony L. Marcott, Andrew H. Nippert, Matthew G. Branch
  • Patent number: 5576962
    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.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: November 19, 1996
    Assignee: Caterpillar Inc.
    Inventors: Alan L. Ferguson, Conrad G. Grembowicz, Larry E. Kendrick
  • Patent number: 5576704
    Abstract: In one aspect of the present invention, a joystick is disclosed. The joystick includes a control shaft having an operator handle and a base. A cardan joint is provided to pivotally mount the control shaft to the base. An actuating body is rigidly attached to the control shaft. Advantageously, a plurality of electrically non-contacting sensors is provided to sense the relative position of the shaft relative to the base. The sensors include a pair of spaced apart electrodes establishing an electrostatic capacity with each other, and a dielectric body being disposed between the electrode pair. Accordingly, as the control shaft pivots, the actuating body engages the dielectric body which moves the dielectric body relative to the electrode pair thereby modifying the capacitance of the sensor.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: November 19, 1996
    Assignee: Caterpillar Inc.
    Inventors: Thomas M. Baker, Michael Furlong, John F. Szentes, Jay Tschetter
  • Patent number: 5575583
    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.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: November 19, 1996
    Assignee: Caterpillar Paving Products Inc.
    Inventors: Conrad G. Grembowicz, Keith R. Schmidt, Alan L. Ferguson
  • Patent number: 5568748
    Abstract: In one aspect of the present invention, a method of effecting shifts in a vehicle is disclosed. The method modifies the transmission shiftpoints in response the wheel power of the vehicle in order to optimize vehicle shifting, while reducing the potential for shift cycling.
    Type: Grant
    Filed: January 11, 1995
    Date of Patent: October 29, 1996
    Assignee: Caterpillar Inc.
    Inventors: Douglas A. Carlson, Todd D. Creger
  • Patent number: 5568992
    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.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: October 29, 1996
    Assignee: Caterpillar Paving Products Inc.
    Inventors: Conrad G. Grembowicz, Alan L. Ferguson, Wade D. Samson, Keith R. Schmidt
  • Patent number: 5560431
    Abstract: Apparatus and method for automatically controlling the position of an earthmoving implement of an earthmoving machine in response to varying ground profiles.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: October 1, 1996
    Assignee: Caterpillar Inc.
    Inventor: Kenneth L. Stratton
  • Patent number: 5551930
    Abstract: The present invention relates to an adaptive control method for an automatic transmission. The method includes the steps of:(a) commanding a predetermined clutch to fill in accordance with a plurality of clutch fill parameters;(b) determining the actual time to completely fill the clutch;(c) comparing the actual fill time with a predetermined fill time; and(d) adjusting at least one of the plurality of clutch fill parameters in response to the comparison in order to modify the clutch fill period during subsequent shifts to the predetermined clutch. Accordingly, the present invention adapts future shifts based on past shifts to improve the shift quality of the transmission.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: September 3, 1996
    Assignee: Caterpillar Inc.
    Inventors: Todd D. Creger, Richard B. League, Randall M. Mitchell, David M. Spurlock, James R. Talbott, Gregory L. Williamson
  • Patent number: 5535124
    Abstract: An anti-spin apparatus for a machine is disclosed. The machine is articulated and has at least one axle set with at least two driven wheels. The anti-spin apparatus includes braking mechanisms which controllably apply braking forces to each of the driven wheels. A controller produces a slip signal having a value responsive to the difference in rotational velocity between the wheels of the axle set. A transducer produces an articulation signal having a value responsive to the angle of articulation of the machine. Further, a microprocessor receives the slip signal and the articulation signal, and produces a braking control signal. One of the braking mechanisms receives the braking control signal and responsively applies the braking forces to the faster rotating wheel.
    Type: Grant
    Filed: December 9, 1993
    Date of Patent: July 9, 1996
    Assignee: Caterpillar Inc.
    Inventors: Javad Hosseini, Michael A. Cobo, Noel J. Rytter, Andrew G. Verheyen
  • Patent number: 5529044
    Abstract: In one aspect of the present invention, a method is disclosed for controlling the fuel injection rate of a hydraulically-actuated fuel injector. A desired actuating fluid pressure is determined based on the engine speed and temperature. The desired actuating fluid pressure is used to control the fuel injection rate to result in quick engine starting.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: June 25, 1996
    Assignee: Caterpillar Inc.
    Inventors: Travis E. Barnes, Brian E. Uhlenhake
  • Patent number: 5528843
    Abstract: In one aspect of the present invention, an automatic control system for loading a bucket of a wheel loader is disclosed. The system includes a pressure sensor that produces pressure signals in response to the hydraulic pressures associated with one of the lift and tilt cylinders. A microprocessor receives the pressure signals, compares at least one of the pressure signals to a predetermined one of a plurality of pressure setpoints, and produces lift and tilt command signals in response to the pressure comparisons. Finally, an electrohydraulic system receives the lift command signals and controllably extends the lift cylinder to raise the bucket through the material, and receives the tilt command signals and controllably extends the tilt cylinder to tilt the bucket to capture the material.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: June 25, 1996
    Assignee: Caterpillar Inc.
    Inventor: David J. Rocke
  • Patent number: 5528928
    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.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: June 25, 1996
    Assignee: Caterpillar Inc.
    Inventors: Thomas M. Baker, George Codina, John W. Crayton
  • Patent number: 5523684
    Abstract: In one aspect of the present invention, an electromagnetic actuator is disclosed. The electromagnetic actuator includes a plunger adapted to move between first and second positions, a pull coil adapted to receive electrical energy and responsively produce a high electromagnetic force causing the plunger to move from the first position to the second position, and a hold coil adapted to receive electrical energy and responsively produce a low electromagnetic force for maintaining the plunger at the second position. A sensing device is included to detect the magnetic flux density produced by the coils and responsively produce a position signal having a magnitude responsive to the position of the plunger. Advantageously, signal conditioning circuitry receives the position signal, and de-energizes the pull coil in response to the position signal indicating that the plunger is at the second position.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: June 4, 1996
    Assignee: Caterpillar Inc.
    Inventor: Daniel E. Zimmermann
  • Patent number: 5509520
    Abstract: An electrohydraulic control device for a drive train of a machine is disclosed. The drive train includes an engine, a transmission, and a torque converter having a rotating housing. The torque converter is drivingly connected between the engine and the transmission. The torque converter also includes an impeller element. An impeller clutch connects the impeller element to the rotating housing. An impeller clutch electrohydraulic valve produces fluid flow to the impeller clutch to controllably engage and disengage the impeller clutch. A torque converter speed sensor senses the output speed of the torque converter and responsively produces a torque converter speed signal.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: April 23, 1996
    Assignee: Caterpillar Inc.
    Inventors: William C. Evans, Daniel E. Henderson, Robert A. Herold, Noel J. Rytter
  • Patent number: 5509293
    Abstract: A method for dynamically measuring and indicating payload weight for a machine having at least one lift cylinder for elevating a payload carrier is provided. The method includes the steps of lifting a load of known mass during calibrating and sensing a calibration lift cylinder velocity during calibration. To determine payload, lift cylinder hydraulic pressure and lift cylinder extension are sensed during a lifting operation of the machine. A first estimate of the payload is determined as a function of the lift cylinder hydraulic pressure and extension. The method further includes the steps of determining an operating lift cylinder velocity during the lifting operation and determining a velocity correction factor as a function of the calibration lift cylinder velocity and the operating lift cylinder velocity. A second estimate of the payload is calculated as a function of the first estimate and the velocity correction factor.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: April 23, 1996
    Assignee: Caterpillar Inc.
    Inventor: Arundhati Karumanchi
  • Patent number: 5505100
    Abstract: In one aspect of the present invention, a method for controlling an interrupted shift for a powershift transmission is disclosed. The method first determines which clutches are active and then classifies each of the active clutches. Thereafter, the method calculates the timing associated with the engagement and disengagement of the classified active clutches to result in a smooth transition to the final selected gear.
    Type: Grant
    Filed: September 29, 1994
    Date of Patent: April 9, 1996
    Assignee: Caterpillar Inc.
    Inventors: Randall M. Mitchell, Alan L. Stahl, James R. Talbott
  • Patent number: 5506508
    Abstract: In one aspect of the present invention, an apparatus detects a shorted winding condition of a solenoid coil. The apparatus includes a reference solenoid that is connected to a test solenoid. A sine generator drives the reference solenoid with a sinusoidal waveform to cause an induced voltage across the test solenoid. A meter determines the voltage difference between the solenoids and compares the voltage difference to a predetermined value.
    Type: Grant
    Filed: June 12, 1995
    Date of Patent: April 9, 1996
    Assignee: Caterpillar Inc.
    Inventor: Daniel E. Zimmermann
  • Patent number: 5502378
    Abstract: 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.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: March 26, 1996
    Assignee: Caterpillar
    Inventors: Lonnie D. Atteberry, Timothy A. Boston, John W. Crayton, Jeffrey J. Riebschlager, Noel J. Rytter