Patents by Inventor David W. Bruce

David W. Bruce 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: 6457502
    Abstract: This invention relates to a method and apparatus for maintaining equal air pressure in a pair of tires on a work machine. The invention provides a valve body with a pair of piston chambers. A piston is reciprocatably positioned within each piston chamber, the pistons are biased toward a first closed end of the piston chambers. The closed end of each piston chamber is connected by a passageway to one of the tires. Each piston chamber is additionally fluidly connected to the other piston chamber. When the air pressure in each tire is above a predetermined amount the pistons are moved away from the closed end of the piston chamber and airflow is permitted between the piston chambers thereby balancing the tire pressures. If the pressure in either tire is below the predetermined minimum, the piston in that respective piston chamber moves toward the first end to block, airflow between the piston chambers.
    Type: Grant
    Filed: December 15, 2000
    Date of Patent: October 1, 2002
    Assignee: Caterpillar Inc
    Inventors: Douglas W. Bell, David W. Bruce, Jon R. Greiner, David R. Hinton
  • Publication number: 20020074069
    Abstract: This invention relates to a method and apparatus for maintaining equal air pressure in a pair of tires on a work machine. The invention provides a valve body with a pair of piston chambers. A piston is reciprocatably positioned within each piston chamber, the pistons are biased toward a first closed end of the piston chambers. The closed end of each piston chamber is connected by a passageway to one of the tires. Each piston chamber is additionally fluidly connected to the other piston chamber. When the air pressure in each tire is above a predetermined amount the pistons are moved away from the closed end of the piston chamber and airflow is permitted between the piston chambers thereby balancing the tire pressures. If the pressure in either tire is below the predetermined minimum, the piston in that respective piston chamber moves toward the first end to block, airflow between the piston chambers.
    Type: Application
    Filed: December 15, 2000
    Publication date: June 20, 2002
    Inventors: Douglas W. Bell, David W. Bruce, Jon R. Greiner, David R. Hinton
  • Patent number: 6360840
    Abstract: An apparatus for controlling temperature of fluid in a rear axle assembly includes a rear axle housing having an internal component chamber. The internal component chamber has a rear axle sump located therein. The apparatus also includes a temperature control operational pressure source coupled to the internal component chamber. The apparatus further includes a diverter valve coupled to the temperature control operational pressure source. The apparatus includes a heating fluid return line interposed between the diverter valve and the rear axle sump, and includes a cooling fluid return line interposed between the diverter valve and the rear axle housing. The temperature control operational pressure source is selectively operable between (i) a first rate mode in which it advances fluid from the internal component chamber at a first flow rate, and (ii) a second rate mode in which it advances fluid from the internal component chamber at a second flow rate.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: March 26, 2002
    Assignee: Caterpillar Inc.
    Inventors: Douglas W. Bell, David W. Bruce, David R. Hinton