Patents by Inventor David B. Clifton

David B. Clifton 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: 6777823
    Abstract: A continuous power system assembly is provided that includes an integrated shaft-driven unit. The unit contains a turbine, an alternator, a flywheel and a feed pump, all of which are coupled to the shaft. During various modes of operation, any of the turbine, alternator or flywheel may provide the torque used to drive the shaft. When the alternator is not providing the necessary torque to drive the shaft, it is operated as a generator that provides back-up power to a load. The present invention also includes a unique nozzle design that improves the ease with the nozzles may be manufactured in comparison to known designs. The nozzle is manufactured as two halves which are mated as part of the manufacturing process. The individual nozzles may, because only half of the nozzle segments exist on either half of the nozzle block, be easily manufactured using conventional machining.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: August 17, 2004
    Assignee: Active Power, Inc.
    Inventors: Gail Roberts, Philip Keene, David Lowe, James Hunt, Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6512305
    Abstract: An uninterruptible power supply (UPS) system supplies power to computers, medical apparatus or other critical loads when primary power supply falters. The UPS system includes an electrical machine connected to a turbine that can be rotated by a motive fluid from a fluid supply. The electrical machine can be a dual purpose electrical machine (a motor/generator) or a two unit machine (one motor and one generator in a single housing or in separate housings) connected to the turbine. When power is supplied from the primary power supply to the critical load, the electrical machine acts as a motor to rotate the turbine and energy is stored by the turbine rotor in the form of rotational momentum. When power from the primary power supply falters, the rotational momentum of the turbine rotor initially rotates the electrical machine which acts as a generator to provide power to the critical load.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: January 28, 2003
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6463738
    Abstract: A continuous power system provides a continuous supply of power to a load in the event that primary power fails or is degraded. The continuous power system includes an electrical machine, a turbine and a flywheel coupled to a shaft. When utility power is present, the machine operates as a motor to drive the shaft. During outages, the electrical machine operates as a generator to provide power to the load. Kinetic energy stored in the flywheel drives the shaft during initial power interruptions. During further short-term interruptions, a thermal energy supply (or thermal storage device) is used to provide vaporized liquid to the turbine so that the turbine drives the shaft. If the power loss or failure is extended, the turbine is driven by vapor produced by an evaporator heated from an external fuel supply. Numerous methods and apparatus are also described for reducing system losses and improving overall performance.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: October 15, 2002
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton, Kenneth E. Nichols, Michael D. Forsha, James E. Dillard, William D. Batton
  • Patent number: 6255743
    Abstract: An uninterruptible power supply (UPS) system supplies electric power to computers, medical apparatus or other critical loads when a primary power supply fails. The UPS system includes an electrical machine drivingly connected to a turbine which can be rotated by a motive fluid from a fluid supply. The electrical machine can be a dual purpose electrical machine (a motor/generator) or a two unit machine (one motor and one generator in a single housing or in separate housings) drivingly connected to a turbine which can be rotated by a motive fluid supply. When power is supplied from the primary power supply to the critical load, the electrical machine acts as a motor to rotate the turbine, and energy is stored by the turbine rotor in the form of rotational momentum. When power from the primary power supply fails, the rotational momentum of the turbine rotor initially rotates the electrical machine which acts as a generator to provide power to the critical load.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: July 3, 2001
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6192687
    Abstract: Uninterruptible power supplies are provided that utilize a material to provide a source of thermal energy that may be converted to electrical energy to produce backup electrical power for a load. In some embodiments, a hot tank assembly is utilized to hold a liquid heated to a predetermined temperature. A closed-loop pipe containing, water for example, is immersed in the heated liquid. Upon the loss of primary power, the water flows into the heat exchanger where it is raised above its boiling temperature. The steam is then passed to a heat engine (e.g., a turbine-based system) that converts the heated steam to mechanical energy by causing the heat engine rotor to rotate. A generator is physically coupled to the heat engine so that the rotation of the heat engine rotor drives the generator. The generator produces AC power which is converted to DC and again back to AC before being provided to the load. In other embodiments, a solid mass, such as a block of iron, is heated to a predetermined temperature.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: February 27, 2001
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6124702
    Abstract: Electrical machine cycloconverter devices are provided that produce output signals in which the frequency, amplitude and phase are independent of rotor speed. The cycloconverters produce highly efficient increased output by providing multi-tap armatures that include multiple armature coils arranged such that at least two coils may be connected in series to an electrical load. Such configurations produce output signals that include multiple distinct voltage amplitude steps. In preferred embodiments, either rotating permanent magnets or field coils in conjunction with rotating steel teeth induce a voltage in the armature coils. The level of induced voltage is determined by the switching sequence of one or more armature coils that are switched ON and OFF in series, parallel, or series and parallel by semiconductor switches.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: September 26, 2000
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 5980193
    Abstract: A magnetically levitated transport device provides levitation and propulsion of a vacuum carriage. An air carriage is moved by conventional means through both linear and angular displacements. Non-magnetic coils mounted on the air carriage interact with permanent magnets mounted on the vacuum carriage to magnetically link the carriages together using Lorentz forces. The non-magnetic coils, which are exposed to the fields generated by the permanent magnets, produce the Lorentz forces when driven by drive currents in response to inputs received from position sensors. In one embodiment, power requirements are reduced by adding permanent magnets to the air carriage that interact with some of the permanent magnets on the vacuum carriage to provide forces that substantially levitate all of the static load.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: November 9, 1999
    Assignee: Magnetic Bearing Technologies, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton
  • Patent number: 5969457
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: October 19, 1999
    Assignee: Active Power, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton
  • Patent number: 5955816
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: September 21, 1999
    Assignee: Active Power, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton
  • Patent number: 5932935
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: August 3, 1999
    Assignee: Active Power, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton, James A. Andrews, Scott R. Little
  • Patent number: 5929548
    Abstract: A high inertia inductor-alternator energy storage device provides backup energy in a simple, compact device. The inductor-alternator stores an acceptable level of energy via an improved rotor that provides a high level of rotational inertia. The improved rotor can be manufactured at a reduced cost due to reduced milling requirements. Moreover, the inductor-alternators of the present invention have reduced complexity and increased reliability as a result of the geometry of the improved rotor.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: July 27, 1999
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 5920138
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: July 6, 1999
    Assignee: Active Power, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton, James A. Andrews, Scott R. Little
  • Patent number: 5905321
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: May 18, 1999
    Assignee: Active Power, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton, James A. Andrews, Scott R. Little
  • Patent number: 5731645
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: March 24, 1998
    Assignee: Magnetic Bearing Technologies, Inc.
    Inventors: David B. Clifton, Joseph F. Pinkerton, James A. Andrews, Scott R. Little
  • Patent number: 5525848
    Abstract: A magnetic bearing system has a magnetic bearing and an electric generator for activating the magnetic bearing. The various components of the system are mounted respectively on a rotor and a stator. The magnetic bearing is of the magnetic attraction type or of the Lorentz force type. It has first and second subassemblies, one of which is on the rotor and the other of which is on the stator. The generator has at least one magnet subassembly and at least one loop subassembly, one of which is on the rotor and the other of which is on the stator. The magnet subassembly has field magnets for creating magnetic fields. The loop subassembly has loops which travel through the magnetic fields.
    Type: Grant
    Filed: April 12, 1994
    Date of Patent: June 11, 1996
    Assignee: Magnetic Bearing Technologies, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 5471105
    Abstract: A magnetic bearing system has magnets for producing magnetic fields, and a member which carries loop portions of electrically conductive material. The member and magnets are relatively rotatable about an axis of rotation so that the loop portions travel along a prescribed circular path relative to and through the magnetic fields. The magnetic fields subject the loop portions to magnetic flux to produce electromotive forces in the loop portions when the loop portions deviate from the prescribed circular path. This induces an electrical current in the loop portions. The direction of this electrical current is such that, in the presence of the magnetic fields, Lorentz forces are exerted on the loop portions and the loop-carrying member in directions which are lateral with respect to the circular path. To avoid undesired current flow when the member is rotating on its prescribed axis, at least the first and second loop portions are electrically interconnected to form a closed loop.
    Type: Grant
    Filed: April 6, 1994
    Date of Patent: November 28, 1995
    Assignee: Magnetic Bearing Technologies, Inc.
    Inventors: David B. Clifton, Scott R. Little, Joseph F. Pinkerton
  • Patent number: 5345128
    Abstract: An alternating current electromagnet is used in a magnetic bearing in which one or more electrically conductive loops travel on a prescribed path through a magnetic field produced by the electromagnet. An electrical current is induced in the loop whenever it deviates from its prescribed path. A power supply drives the electromagnet(s) at a frequency at which the magnetic field interacts with the currents induced in the loop to force a deviant loop laterally toward the prescribed path. Capacitors may be connected in series with the loops to provide them with the desired reactances.
    Type: Grant
    Filed: July 23, 1993
    Date of Patent: September 6, 1994
    Assignee: Magnetic Bearing Techologies, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton, Scott R. Little
  • Patent number: 5208844
    Abstract: Discrete, contained charged particle bundles are converted into heat energy for driving a load. In one embodiment the bundles propagate between a cathode and anode in a gap between a pair of solid dielectric members, which gap has a dimension between a pair of facing surfaces of the dielectric members equal approximately to the diameter of a group of such bundles propagating together. The bundles are derived in response to high voltage short duration pulses derived from a modified Blumlein switch. The bundles are periodically derived and converted to current that flows in a circuit having a resonant frequency equal to the frequency of the bundles. In another embodiment the bundles are derived from a cathode including a liquid metal pool in contact with a solid dielectric surface along which the bundles propagate to an x-ray emitting target or an anode that is heated by the bundles, to convert the x-rays into useful emission and/or the heat into useful work.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: May 4, 1993
    Assignee: Jupiter Toy Company
    Inventors: Harold E. Puthoff, George W. Church, Jr., David B. Clifton, Scott R. Little