Patents Represented by Attorney, Agent or Law Firm Robert E. Muir
  • Patent number: 4887454
    Abstract: Off-highway trucks generally rely on a suspension system which employs a plurality of gas-over-liquid type struts. These struts are critical to proper operation of the vehicle such that a single collapsed strut can have serious manifestations in structural damage, tire wear, and payload monitor accuracy. These consequences can be mitigated by an accurate and reliable strut monitor. Pressure type sensors are disposed on each of the struts and their pressure is monitored during three critical phases of operation. These phases include static, loading, and roading modes and each mode requires a distinct method for detecting a collapsing strut. The presence of a collapsing strut, detected by any of the three methods, is communicated to the vehicle operator whereby operation can be immediately suspended. The system avoids the serious consequences of vehicle operation with a collapsed strut by providing the operator with immediate and positive feedback on the condition of the struts.
    Type: Grant
    Filed: January 9, 1989
    Date of Patent: December 19, 1989
    Assignee: Caterpillar Inc.
    Inventors: Christos T. Kyrtsos, F. Paul Lutgen, Adam J. Gudat
  • Patent number: 4866419
    Abstract: In the field of off-highway trucks, tires represent a significant portion of operating expenses. Underinflated tires wear more quickly than properly inflated tires. This invention pertains to an apparatus for detecting an underinflated tire of a work vehicle (12) and displaying the information to the operator or service personnel. The apparatus senses internal pressures of preselected struts (16,18), and converts these signals into an indication of relative inflation pressures of the associated tires (32). When a tire is underinflated relative to another tire by a preselected amount, an underinflation signal is transmitted to a display. The display indicates to the operator that a tire is underinflated.
    Type: Grant
    Filed: November 3, 1987
    Date of Patent: September 12, 1989
    Assignee: Caterpillar Inc.
    Inventors: Christos T. Kyrtsos, Gregory E. Long
  • Patent number: 4858576
    Abstract: The present invention pertains to a control system for igniting devices (28,30,32,34,36,38) used in an internal combustion engine (24). In order to ignite alcohol fuel in a diesel engine, the fuel must be heated before or during compression. Glow plugs (28,30,32,34,36,38) conveniently provide heat, but have a short life in such continuous applications. Glow plugs must be accurately controlled to prevent overheating, which leads to open-circuiting. Individual constant voltage controls attempt to provide this function, but are only moderately successful. They are costly and complex, and provide only moderate protection from overheating. Since glow plug resistance correlates to glow plug temperature, resistance control provides better protection against glow plug overheating. Therefore, an apparatus (20) monitors the resistance of a single glow plug (28), and controls the resistance of each glow plug to a preselected resistance value.
    Type: Grant
    Filed: November 27, 1987
    Date of Patent: August 22, 1989
    Assignee: Caterpillar Inc.
    Inventors: James R. Jeffries, Michael R. Verheyen
  • Patent number: 4858818
    Abstract: A method is provided for use with non-contacting torque sensors. Many torque sensors use a sheet of magnetostrictive material wrapped about the shaft whose torque is to be measured. The methods used to wrap and affix the sheet of magnetostrictive material induce a prestress into the sheet, which leads to early saturation of the magnetostrictive material. The prestress diminishes the useful range of the torque sensor. As a solution, a method is provided for bonding a magnetostrictive material sheet to a shaft while minimizing stress of the magnetostrictive sheet. By bending a magnetostrictive material sheet and a carrier sheet about the mandrel and bonding the sheets together at a first preselected temperature, cooling them to form a cylinder having a magnetostrictive material outer layer and a carrier inner layer, and bonding the cylinder to a shaft at a second predetermined temperature, the stresses induced in the magnetostrictive sheet are minimized.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: August 22, 1989
    Assignee: Caterpillar Inc.
    Inventors: Lawrence D. Knox, Izrail Tsals
  • Patent number: 4852657
    Abstract: Agricultural vehicles have heretofore lacked an adaptive implement hitch control and have correspondingly suffered from poor controllability of the hitch when the mass of the implement is varied significantly. The apparatus employs a sensor connected to and movable with the hitch such that a variable magnitude electrical signal is delivered which corresponds to the instantaneous hitch position. This signal is electronically differentiated to produce a signal indicative of actual hitch velocity. The hitch position and velocity signals are both used as feedback signals to close the control loop of the control and thereby provide an adaptive hitch velocity control.
    Type: Grant
    Filed: July 2, 1986
    Date of Patent: August 1, 1989
    Assignee: Caterpillar Inc.
    Inventors: Gerald D. Hardy, John P. Hoffman, Larry E. Kendrick
  • Patent number: 4852674
    Abstract: In the field of off-highway trucks, overloading and disproportionate load placement lead to undesirable vehicle stresses. The present invention pertains to an apparatus for displaying the distribution of the load, in an off-highway truck, to both the truck operator and the loader operator. The information is conveyed to the operators using displays having varying color ranges generally indicative of the load in portions of the dump body of the truck. Using this tool the truck operator attains optimum positioning of the truck prior to and during the loading cycle, while the loader operator directs loads to portions of the dump body having lower displayed loads.
    Type: Grant
    Filed: September 14, 1988
    Date of Patent: August 1, 1989
    Assignee: Caterpillar Inc.
    Inventor: Adam J. Gudat
  • Patent number: 4845975
    Abstract: Off-highway trucks generally rely on a suspension system which employs a plurality of gas-over-liquid type struts. These struts are critical to proper operation of the vehicle such that a single collapsed strut can have serious manifestations in structural damage, tire wear, and payload monitor accuracy. These consequences can be mitigated by an accurate and reliable strut monitor. Pressure type sensors are disposed on each of the struts and their pressure is monitored during three critical phases of operation. These phases include static, loading, and roading modes and each mode requires a distinct method for detecting a collapsing strut. The presence of a collapsing strut, detected by any of the three methods, is communicated to the vehicle operator whereby operation can be immediately suspended. The system avoids the serious consequences of vehicle operation with a collapsed strut by providing the operator with immediate and positive feedback on the condition of the struts.
    Type: Grant
    Filed: March 2, 1988
    Date of Patent: July 11, 1989
    Assignee: Caterpillar Inc.
    Inventors: Christos T. Kyrtsos, F. Paul Lutgen, Adam J. Gudat
  • Patent number: 4835719
    Abstract: A payload monitoring system of a work vehicle includes a software controlled method of predicting when one additional bucketload of material will properly fill the vehicle to its rated capacity. The system calculates the actual magnitude of each bucketload of material and adds that value to the present payload to predict the future payload resulting from an additional bucketload of material. When the predicted future payload encompasses the rated capacity, the system signals the operators of both the work vehicle and the loading vehicle that one additional pass will complete the loading process.
    Type: Grant
    Filed: August 3, 1987
    Date of Patent: May 30, 1989
    Assignee: Caterpillar Inc.
    Inventor: Giles K. Sorrells
  • Patent number: 4829956
    Abstract: A method detects the magnitude of knock in an internal combustion engine. Each knock is quantified into a discrete level which gives an indication of the operating condition of the engine. The discrete level signals provide information helpful during engine calibration and engine monitoring. After a predetermined number of level signals indicative of preselected magnitudes of knock are received, an engine shutdown signal is delivered which ceases engine operation.
    Type: Grant
    Filed: November 2, 1987
    Date of Patent: May 16, 1989
    Assignee: Caterpillar Inc.
    Inventors: Bryce H. Rehn, Ronald J. Penick, Daniel W. Esters, Harold A. Baker
  • Patent number: 4806847
    Abstract: A sensor for sensing the level of oil or transmission fluid under both normal and extreme temperature conditions. The only active components of the sensor have input and leakage currents substantially lower than those of diodes and current sources under high temperature conditions. The sensor has a probe, including a pair of electrodes forming a level detecting capacitor, adapted to extend in the vessel to detect the level of the liquid. A reference capacitor is included which has a capacitance substantially the same as the capacitance of the level detecting capacitor when no dielectric liquid is present between the electrodes of the level detecting capacitor. Circuitry is provided for measuring the capacitance of each capacitor and for deriving from the capacitance measurements a signal proportional to the level of the dielectric liquid at the sensor. Circuitry is also provided for testing whether the reference capacitor is operating properly.
    Type: Grant
    Filed: December 9, 1986
    Date of Patent: February 21, 1989
    Assignee: Caterpillar Inc.
    Inventors: Kim W. Atherton, Charles R. Clow, Patrick H. Mawet
  • Patent number: 4804893
    Abstract: An apparatus for an electric drive vehicle which provides linear deceleration via electrical braking. The apparatus monitors vehicle speed and adjusts the duty cycle of a chopper circuit according to look-up tables. These table correlate vehicle speed and desired deceleration rate to braking torque, thereby enabling the apparatus to maintain a preselected deceleration through the entire stopping distance and to precisely position the vehicle.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: February 14, 1989
    Assignee: Caterpillar Industrial Inc.
    Inventor: Grant C. Melocik
  • Patent number: 4800721
    Abstract: A control lever is provided for effecting positional control of a work implement. An actuator means applies a force to the control lever in response to a sensed load being applied to the work implement. The force applied to the implement control lever is in proportion to the load being applied to the work implement, thereby giving the operator a feel for the load being applied to the implement.
    Type: Grant
    Filed: February 13, 1987
    Date of Patent: January 31, 1989
    Assignee: Caterpillar Inc.
    Inventors: Richard A. Cemenska, Marvin P. Schneider, Thomas J. Buege
  • Patent number: 4792995
    Abstract: A self guided vehicle has a roller deck controllably powered by an electric motor to accept and deliver loads on both the left and right side of the vehicle. An infrared communication system is employed to coordinate the overall transfer of these loads between the vehicle and a docking station. The communication system performs the multiple functions of locating the docking station relative to the left and right side of the vehicle, determining the direction the load is to be transferred, and controlling the direction of motor rotation to effect such a transfer.
    Type: Grant
    Filed: August 19, 1987
    Date of Patent: December 20, 1988
    Assignee: Caterpillar Industrial Inc.
    Inventor: Joseph J. Harding
  • Patent number: 4791583
    Abstract: A method for generating a plurality of points that lie on the surface of a blended solid model. These points are obtained from the unblended solid model by a numerical solution to a convolution integral, wherein the convolution integral includes a spherically symmetric blending function with a size responsive to the blend radius desired for each of one or more regions on the solid model. For example, the spherical blending function may possess a constant value everywhere inside a sphere of radius R, and a value of zero outside (here called a "hard sphere"), or it may be represented by other functions of the radial direction, more specifically, the gaussian bell curve, in which case it will be called a "gaussian sphere". The numerical solution to the convolution integral is performed iteratively by placing the blending sphere at a plurality of locations along each of a set of rays that are defined substantially normal to and intersecting the solid model surface.
    Type: Grant
    Filed: May 4, 1987
    Date of Patent: December 13, 1988
    Assignee: Caterpillar Inc.
    Inventor: Stephen Colburn
  • Patent number: 4787964
    Abstract: Gas diffusion electrodes, gas generating or consuming electrochemical cells utilizing such electrodes, and a method of preparing such electrodes are disclosed. The electrode comprises an electronically conductive porous body defining respective gas and electrolyte contacting surfaces. The electrode is prepared by forming the porous body, disposing the electrolyte contacting surface in contact with an electrolyte, and contacting the gas contacting surface with a gaseous atmosphere. Current is passed through the porous body at a degree of electrode polarization much higher than normal whereby modification of the electrode material is effected. If desired, a catalyst may be incorporated in the electrode and is subjected to pretreatment as well. The inventive electrodes exhibit superior voltage performance under oxygen polarization conditions.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: November 29, 1988
    Assignee: Caterpillar Industrial Inc.
    Inventors: Arnold Z. Gordon, Ernest B. Yeager, Donald A. Tryk, M. Sohrab Hossain
  • Patent number: 4745893
    Abstract: An oil level sensor includes a sensor body adapted to be mounted to the block or casing of an oil-containing reservoir. A probe including a pair of electrodes forming a capacitor extends from the sensor body so that the capacitor will be at least partially immersed in the oil to detect the level thereof. At least one of the electrodes is insulated so that the apparent capacitance of the capacitor is relatively insensitive to any change in the conductivity of the oil at high temperatures. Circuitry is provided in response to the capacitance of the capacitor for signalling the level of the oil, which capacitance is a function of the oil level. The sensor body is mounted to the block by external threads on the probe. The electrodes of the probe extend proximally past the threads to provide an increased capacitance for the sensor. The electrodes of the probe are concentric and the inner electrode is supported at both ends to reduce fatigue.
    Type: Grant
    Filed: December 3, 1986
    Date of Patent: May 24, 1988
    Assignee: Caterpillar Inc.
    Inventors: Kim Wesley Atherton, A. Brinkley Barr, Thomas M. Harmon, Michael M. Van Schoiack, Marvin E. Vandehey, Richard D. Weyerts, Charles R. Clow, Patrick H. Mawet
  • Patent number: 4740778
    Abstract: In the field of automated guided vehicles it is particularly important that speed and steering angle feedbacks be accurate and reliable. Any deviations in these feedback signals should be promptly detected and used to alter operation of the vehicle. An apparatus constantly monitors the time varying output signals of a pair of resolvers respectively associated with wheel rotation and steering angle. The loss of either of the resolver signals for more than a preselected duration of time related to the excitation frequency and vehicle speed results in the power delivered to an electric drive motor being discontinued and the vehicle brakes being applied.
    Type: Grant
    Filed: June 15, 1987
    Date of Patent: April 26, 1988
    Assignee: Caterpillar Industrial Inc.
    Inventors: Joseph J. Harding, Victor E. Noviski
  • Patent number: 4737705
    Abstract: Known linear position sensors suffer from inaccuracies owing to severe environmental conditions, such as temperature and humidity. Physical damage to sensors exposed to rugged work conditions is a limiting factor in the expected life of sensors used, for example, in the heavy equipment industry. A pair of loop antennas mounted internal to an extensible coaxial cavity respectively transmit and receive electromagnetic signals in the radio frequency range exciting a transverse electromagnetic field in the cavity when the frequency of the signal corresponds to the resonant frequency of the cavity. The resonant frequency of the cavity is primarily dependent upon the longitudinal length of the cavity. Therefore, a voltage controlled oscillator acts under the control of a sawtooth voltage waveform of a function generator to controllably deliver a variable frequency signal to the first loop antenna. An RF detector monitors the second loop antenna for an indication that the resonant frequency has been reached.
    Type: Grant
    Filed: November 5, 1986
    Date of Patent: April 12, 1988
    Assignee: Caterpillar Inc.
    Inventors: Ali Bitar, Adam J. Gudat, Brian D. Huggins, Wesley E. Jacobson, John F. Szentes
  • Patent number: 4731347
    Abstract: A glass frit comprising about 60% by weight of glass formers, 30% by weight of monovalent fluxes and 10% by weight of divalent fluxes; the glass formers consisting essentially of SiO.sub.2 and B.sub.2 O.sub.3 ; the monovalent fluxes consisting essentially of Li.sub.2 O, Na.sub.2 O and K.sub.2 O; the divalent fluxes being selected from the group consisting of CaO, SrO, BaO and PbO; and trace elements not exceeding 10% by weight. Preferably the glass frit has the following composition, in terms of oxides:______________________________________ SiO.sub.2 49% B.sub.2 O.sub.3 12% Li.sub.2 O 3.6% Na.sub.2 O 14.4% K.sub.2 O 11.4% CaO 5% SrO 1.85% BaO 2.75% ______________________________________The glass frit has a coefficient of thermal expansion of 7.2.times.10.sup.-6 /.degree. F. (13.times.10.sup.-6 /.degree. C.) over the range from room temperature to 600.degree. F. (316.degree. C.). It is useable to make a slip where it can be fired at temperatures around 950.degree. F. (510.degree. C.
    Type: Grant
    Filed: March 21, 1986
    Date of Patent: March 15, 1988
    Assignee: Solar Turbines Incorporated
    Inventor: Alvin R. Stetson
  • Patent number: 4726333
    Abstract: The present invention pertains to a control system for igniting devices used in an internal combustion engine. In order to ignite alcohol fuel in a diesel engine, the fuel must be heated before or during compression. Glow plugs conveniently provide heat, but have a short life in such continuous applications. Glow plugs must be accurately controlled to prevent overheating, which leads to open-circuiting. Individual constant voltage controls attempt to provide this function, but are only moderately successful. They are costly and complex, and provide only moderate protection from overheating. Since glow plug resistance correlates to glow plug temperature, resistance control provides better protection against glow plug overheating. Therefore, an apparatus monitors the resistance of a single glow plug, and controls the resistance of each glow plug to a preselected resistance value.
    Type: Grant
    Filed: November 28, 1986
    Date of Patent: February 23, 1988
    Assignee: Caterpillar Inc.
    Inventor: Michael R. Verheyen