Patents by Inventor Donna J. Murr

Donna J. Murr has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6204772
    Abstract: The present invention provides a method and apparatus for monitoring the operation of a mobile machine. The machine includes a mobile communicator adapted to communicate with a remote monitoring station. The method includes the steps of receiving a configuration message from the remote monitoring station via a wireless communication link, comparing at least one of a current machine position to the configuration information a current machine time of operation to the configuration message, and sending an alarm message to the remote monitoring station in response the comparison.
    Type: Grant
    Filed: December 16, 1999
    Date of Patent: March 20, 2001
    Assignee: Caterpillar Inc.
    Inventors: Rodney W. DeMay, David B. Vernon, Daniel C. Wood, Donna J. Murr
  • Patent number: 6152702
    Abstract: An apparatus and method for sensing a parameter of a hydraulic pump. The hydraulic pump includes a housing and an input shaft. The shaft is rotationally driven relative to the housing and electrically coupled to the housing. The hydraulic pump forms a variable capacitor. The apparatus includes an electrode portion positioned adjacent to the input shaft and is electrically isolated from the housing and input shaft. The electrode portion and the input shaft form a fixed capacitor. The fixed capacitor and the variable capacitor are coupled. The apparatus supplies electrical energy to the electrode portion and produces a capacitive signal indicative of the capacitance value of the variable capacitor. The apparatus further applies a filter to the capacitive signal and produces a filtered capacitive signal. The parameter of the hydraulic pump is determined as a function of the filtered capacitive signal.
    Type: Grant
    Filed: March 24, 1999
    Date of Patent: November 28, 2000
    Assignee: Caterpillar Inc.
    Inventors: George Codina, Donna J. Murr
  • Patent number: 5808907
    Abstract: A method for providing information relating to a machine to a user is provided. The method includes the steps of sensing predetermined events relating to the machine and producing corresponding event signals, delivering the event signals to a remote site, comparing the event signals to a profile of events corresponding to the user, and delivering a notification signal to the user if the event signals match the profile.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: September 15, 1998
    Assignee: Caterpillar Inc.
    Inventors: Satish M. Shetty, David R. Schricker, Donna J. Murr
  • Patent number: 5672831
    Abstract: An apparatus for measuring the flow rate of a liquid in a line includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: September 30, 1997
    Assignee: Caterpillar Inc.
    Inventors: George Codina, Chandrasekar Ramamoorthy, Donna J. Murr
  • Patent number: 5670721
    Abstract: An apparatus for measuring the pressure of a liquid in a container includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the elapsed time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference and thus, the pressure within the container.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: September 23, 1997
    Assignee: Caterpillar Inc.
    Inventors: George Codina, Chandrasekar Ramamoorthy, Donna J. Murr
  • Patent number: 5668309
    Abstract: An apparatus for detecting particles within a hydraulic system having a hydraulic line includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the elapsed time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference. A controller receives the pulse width modulated signal and detects particles by comparing the duration of each pulse with a reference pulse.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: September 16, 1997
    Assignee: Caterpillar Inc.
    Inventors: George Codina, Chandrasekar Ramamoorthy, Donna J. Murr
  • Patent number: 5646539
    Abstract: An apparatus for sensing two parameters of a hydraulic system having a hydraulic line includes a pair of electrodes contained within the line and oppositely spaced, forming a capacitor. The apparatus alternately produces first and second charging currents having first and second constant magnitudes, respectively, and charges the capacitor to respective first and second predetermined voltages. The apparatus detects the time needed to charge to the first and second predetermined voltages and produces a pulse width modulated signal having a series of alternating first and second pulses. The first and second pulses are indicative of the first and second parameters, respectively. The first pulse is defined by the time required to charge the capacitor to the first predetermined voltage. The second pulse is defined by the time required to charge the capacitor to the second predetermined voltage. The apparatus determines the two parameters as a function of the pulse width modulated signal.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: July 8, 1997
    Assignee: Caterpillar Inc.
    Inventors: George Codina, Chandrasekar Ramamoorthy, Donna J. Murr
  • Patent number: 5631568
    Abstract: An apparatus for determining the remaining life of hydraulic fluid in a hydraulic system having a hydraulic container includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the elapsed time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit also produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference. A controller receives the pulse width modulated signal and determines the life of the hydraulic fluid.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: May 20, 1997
    Assignee: Caterpillar Inc.
    Inventors: George Codina, Donna J. Murr, Chandrasekar Ramamoorthy