Patents by Inventor David C. Hoffman

David C. Hoffman 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: 6132466
    Abstract: A temporomandibular joint prosthesis is provided. The prosthesis includes the condyle component for attachment to the ramus of a temporomandibular joint to replace the natural condylar head. The condyle component is attached to the natural ramus by a fixation system that may include plasma-sprayed pegs or plasma-sprayed double screws. The prosthesis further includes a fossa component assembly having a metallic bone attachment member and a plastic bearing. The plastic bearing is disposed and configured for articular bearing engagement with the condyle component of the prosthesis.
    Type: Grant
    Filed: June 11, 1999
    Date of Patent: October 17, 2000
    Inventors: David C. Hoffman, Michael J. Pappas
  • Patent number: 5917719
    Abstract: An internally programmable power supply for use with an AC input voltage supplied to an input terminal for producing a DC output voltage. At least one power conversion module is providing having an input and an output. The input of the at least one power conversion module is adapted to be connected to the AC input. The at least one power conversion module includes rectifier means for converting the AC voltage to a DC voltage and a filter to provide the DC output voltage. A digital controller is connected to at least one power conversion module and includes a feedback network having a plurality of feedback components for forming a feedback loop. A microprocessor is provided and a keyboard accessible to the user is coupled to the microprocessor. A logic device is coupled to the microprocessor and is provided with a logic programming interface.
    Type: Grant
    Filed: August 11, 1997
    Date of Patent: June 29, 1999
    Assignee: Power Ten, Inc.
    Inventors: David C. Hoffman, Karl S. Johnson
  • Patent number: 5336022
    Abstract: A method is shown for stabilizing clay bearing soils in which a silica compound is incorporated into the soils in addition to the application of lime. The silica compound can be either an amorphous, silica fume, a crystalline silica, a silica gel, sodium silicate, potassium silicate, finely ground glass or combinations thereof. The silica compound promotes the formation of calcium silicate hydrates over the formation of calcium aluminate hydrates in the resulting pozzolanic reaction occurring in the clay bearing soils. The silica compound and lime can be incorporated into the soils in a single step.
    Type: Grant
    Filed: September 11, 1992
    Date of Patent: August 9, 1994
    Assignee: Chemical Lime Company
    Inventors: J. T. McKennon, Norman L. Hains, David C. Hoffman
  • Patent number: 5228808
    Abstract: A method is shown for stabilizing sulfate bearing soils in which a silica compound is incorporated into the soils with the soils being further stabilized by the application of lime. The silica compound can be either an amorphous, flume silica, a crystalline silica, a silica gel, sodium silicate, potassium silicate or combination thereof. The silica compound and lime can be incorporated into the soils in a single step.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: July 20, 1993
    Assignee: Chemical Lime Company
    Inventors: J. T. McKennon, Norman L. Hains, David C. Hoffman
  • Patent number: 5186742
    Abstract: A process is shown where an arc dust waste produced by an electric arc furnace is conducted to silos and converted to a reusable co-product by means of the addition of a special blend of high calcium and dolomitic quicklime, calcium stearate and pulverized waste paper. The mixture is compressed into compact pellets which, due to their impact integrity and improved shelf life can be pneumatically conveyed intact into storage silos for recycling of the waste electric arc flue dust into the furnace melt. Components of the arc dust deemed leachable and hazardous in landfills, such as zinc, lead and chromium are increased in concentration to a point where it is economical to extract them for resale.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: February 16, 1993
    Assignee: Chemical Lime Company
    Inventors: David C. Hoffman, Norman L. Hains
  • Patent number: 4783728
    Abstract: An uninterruptible power supply includes removable individual power modules, which for example may be 10 kilowatts each and are removable from the overall system without adversely affecting the remaining modules. Each module by means of pulse width modulated switching converts the line AC to DC where it is stored by use of capacitors or a battery and then inverted from DC back to AC. This is done on a three-phase basis without need of any low frequency transformer connection. Common input and output control units provide for the basic pulse width modulated switching signals and other necessary signals.The efficiency and speed of the system is enhanced by the use of cascode switches, saturable cores in transformers and inductors, and a proportional base drive to the switching transistors.
    Type: Grant
    Filed: July 8, 1987
    Date of Patent: November 8, 1988
    Assignee: Modular Power Corp.
    Inventor: David C. Hoffman
  • Patent number: 4772233
    Abstract: A low resistance connector includes a pin and mating socket. The socket includes a central bore sized for mating engagement with one end of the pin. The socket includes a number of longitudinal slots extending into and parallel with the central bore so the central bore is surrounded by a number of flexible fingers. Intimate electrical contact between the outer surface of the pin and the internal surface of the socket bounding the central bore is achieved by annealing the fingers of the socket to a dead soft condition and by the placement of resilient snap rings around the fingers to bias the fingers against the pin.
    Type: Grant
    Filed: September 19, 1983
    Date of Patent: September 20, 1988
    Assignee: Trilogy Computer Development Partners, Ltd.
    Inventor: David C. Hoffman
  • Patent number: 4691274
    Abstract: Electronic power supply comprising a framework having front and rear sides and top and bottom sides and having a vertically disposed space extending upwardly from the bottom of the framework through the top of the framework. It also is comprised of a plurality of power modules disposed in the framework and having heat sinks extending into the vertically disposed space. Fans are provided for forcing air in a vertical direction through the space.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: September 1, 1987
    Assignee: Modular Power Corporation
    Inventors: Anthony F. Matouk, David C. Hoffman, Donald M. Barrus
  • Patent number: D298616
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: November 22, 1988
    Assignee: Modular Power Corporation
    Inventors: Daniel Aschbacher, Tadao B. Warashina, Anthony F. Matouk, David C. Hoffman