Patents by Inventor Hung T. Du

Hung T. Du 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).

  • Publication number: 20110115314
    Abstract: A power tool has a motor having a stator made by separately forming pole pieces, return path pieces and field coils. The field coils are placed over necks of the pole path pieces and the return path pieces are affixed to the pole pieces. An armature having an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The field coils may be formed so that they extend beyond pole tips of the pole pieces.
    Type: Application
    Filed: January 14, 2011
    Publication date: May 19, 2011
    Inventors: Hung T. Du, Earl M. Ortt, Brandon L. Verbrugge, Garrett P. Mccormick, Michael A. Zemlock, Eric J. Samuelsen, Kevin M. Hogan, Jiaqi Zhang, Ren Hong Wang, Frank A. Mannarino, Allison A. Smith, Therese M. Rakosky, Kyle J. Wheaton, Antonios M. Nicolaidis, Shane Ashley Moll, Eric L. Bernstein
  • Patent number: 7893583
    Abstract: A power tool has a motor having a stator made by separately forming pole pieces, return path pieces and field coils. The field coils are placed over necks of the pole path pieces and the return path pieces are affixed to the pole pieces. An armature having an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The field coils may be formed so that they extend beyond pole tips of the pole pieces.
    Type: Grant
    Filed: March 6, 2006
    Date of Patent: February 22, 2011
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Earl M. Ortt, Brandon L. Verbrugge, Garrett P. McCormick, Michael A. Zemlock, Kevin M. Hogan, Jiaqi Zhang, Ren Hong Wang, Frank A. Mannarino, Spencer G. Maid, Shane Ashley Moll, James C. Benton
  • Publication number: 20110018370
    Abstract: An electric motor has a stator in which an armature is disposed. The armature has a lamination stack having slots in which magnet wires are wound. An armature shaft extends coaxially through the lamination stack and a commutator is disposed on the armature shaft to which ends of the magnet wires are electrically coupled. The magnet wires are at least partially encased in thermally conductive plastic. When the thermally conductive plastic is molded, a balancing feature is formed of the thermally conductive plastic. In aspects, the balancing feature can include a layer of the plastic from which plastic can be removed during balancing; one or more balancing rings adjacent axial sides of the lamination stack from which plastic can be removed to balance the armature; or one or more balancing rings having one or more pockets therein in which one or more weights are disposed to balance the armature.
    Type: Application
    Filed: September 30, 2010
    Publication date: January 27, 2011
    Inventors: Hung T. Du, Richard T. Walter
  • Patent number: 7814641
    Abstract: A method of forming a power tool includes forming and balancing an armature by securing a lamination stack having slots therein on an armature shaft securing a commutator on one end of the armature shaft, winding magnet wires in the slots in the lamination stack and securing ends of the magnet wires to the commutator, and molding plastic to at least partially encase the magnet wires in plastic and forming a balancing feature. Plastic is removed from the balancing feature during dynamic balancing of the armature. The armature is then disposed in a stator to form an electric motor and the electric motor is disposed in a power tool.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: October 19, 2010
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Richard T. Walter
  • Patent number: 7685697
    Abstract: A method of manufacturing a power tool includes forming an armature by placing an electrically insulative sleeve on an armature shaft, securing a lamination stack having slots therein on the armature shaft with the insulative sleeve disposed therebetween, securing a commutator on one end of the armature shaft with the insulative sleeve disposed therebetween, winding magnet wires in the slots in the lamination stack and securing ends of the magnet wires to the commutator, and molding thermally conductive plastic to at least partially encase the magnet wires in plastic. The armature is then disposed in a stator to form an electric motor and the electric motor is disposed in a power tool. In an aspect, electrically insulative plastic is molded in the slots of the lamination stack to form slot liners and around the ends of the lamination stack to form end spiders.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: March 30, 2010
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Joshua F. West, Richard T. Walter
  • Patent number: 7687964
    Abstract: An electric motor has a field assembly, such as a stator, for a dynamoelectric machine has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated with insulating sleeves or insulating slot liners. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assembled together with the field coils, which have also been separately formed.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: March 30, 2010
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Brandon L. Verbrugge, Earl M. Ortt, Michael J. Agnes, Michael A. Zemlock, Robert G. Kusmierski, David J. Smith
  • Publication number: 20100033036
    Abstract: An electric motor has a rotor and a stator. The rotor or the stator has arced permanent magnets that have essentially the same inner radius (IR) and outer radius (OR). In an aspect, the stator has a stator housing having a plurality of poles. Each pole includes a plurality of flat magnets affixed to an inner surface of the stator housing. In an aspect, flats on the outside of the stator housing key the stator assembly in a power tool housing. In an aspect, flat magnets are pre-magnetized, pre-assembled with alternating magnetic polarities, inserted into a stator housing, and remagnetized to a final, desired magnetic polarity configuration. In an aspect, pre-magnetized magnets and unmagnetized magnets are pre-assembled with unmagnetized magnets between magnetized magnets, the pre-assembled magnets inserted into a stator housing, and the unmagnetized magnets magnetized to a final, desired magnetic polarity configuration.
    Type: Application
    Filed: October 12, 2007
    Publication date: February 11, 2010
    Applicant: BLACK & DECKER INC.
    Inventors: Earl M. Ortt, Hung T. Du, Sankarshan Murthy
  • Patent number: 7602137
    Abstract: A power tool having an electronically commutated DC motor capable of providing various operating modes ranging from a maximum efficiency operating mode to a maximum power operating mode. The motor has a rotor having permanent magnets mounted in recesses in a back iron of the rotor. In one embodiment the motor has three phase windings, each having at least a pair of coils. The phase windings are connected in either a delta or a wye configuration via electromechanical or electronic switching components, or a combination of both, by a controller within the tool. The coils in each phase winding can also be switched between series and parallel configurations to configure the motor to provide its various operating modes. In one embodiment a dual wound motor is disclosed that has its phase coils dynamically or statically switchable between series and parallel configurations.
    Type: Grant
    Filed: February 19, 2007
    Date of Patent: October 13, 2009
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Uday S. Deshpande, Joshua D. West, Bhanuprasad V. Gorti, Shailesh Waikar
  • Publication number: 20090206783
    Abstract: A power tool has an electric motor with field windings. In an aspect of the invention, each field winding includes two coils wound with the same number of turns of the same gauge magnet wire. When the motor is first energized, the two coils of each field winding are connected in series, reducing in-rush current. Upon expiration of a soft start period, which can be after the motor reaches a predetermined speed or upon expiration of a predetermined time period, the two coils of each field winding are connected in parallel. In another aspect of the invention, an electric motor used in a power tool includes field windings that are connected in series with a separate start winding when the motor is first energized. Upon expiration of the soft start period, the start winding is bypassed. In another aspect of the invention, the separate start winding includes two sub-windings.
    Type: Application
    Filed: July 10, 2006
    Publication date: August 20, 2009
    Applicant: Black & Decker Inc.
    Inventors: Peter Zhao, Hung T. Du, Garrett P. McCormick
  • Publication number: 20090200891
    Abstract: An electric motor has a field assembly, such as a stator, for a dynamoelectric machine has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated with insulating sleeves or insulating slot liners. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assembled together with the field coils, which have also been separately formed.
    Type: Application
    Filed: April 17, 2009
    Publication date: August 13, 2009
    Applicant: Black & Decker Inc.
    Inventors: Hung T. Du, Brandon L. Verbrugge, Earl M. Ortt, Michael J. Agnes, Michael A. Zemlock, Robert G. Kusmierski, David J. Smith
  • Patent number: 7528520
    Abstract: An electric motor has a field assembly, such as a stator, for a dynamoelectric machine has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated with insulating sleeves or insulating slot liners. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assembled together with the field coils, which have also been separately formed.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: May 5, 2009
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Brandon L. Verbrugge, Earl M. Ortt, Michael J. Agnes, Michael A. Zemlok, Robert G. Kusmierski, David J. Smith
  • Publication number: 20090101379
    Abstract: A cordless power tool (300) has a transmission (12) having multiple speed ranges In the light torque range, the speed of a motor (8) of the cordless power tool is held constant to hold an output speed of the transmission (12) constant until motor power reaches a predetermined percentage of the maximum watts out of the motor.
    Type: Application
    Filed: March 2, 2007
    Publication date: April 23, 2009
    Inventors: Hung T. Du, Josh West
  • Patent number: 7494035
    Abstract: A pneumatic compressor capable of supplying compressed gas to a pneumatic tool. The compressor can be powered alternatively by either a battery or an AC power source. The compressor comprises a permanent magnet DC electric motor and circuitry for converting the AC power source to DC power. The compressor includes a receptacle for accommodating one or more of a plurality of batteries and includes circuitry for using batteries having different voltages. The AC power source may also be used to charge a battery connected to the compressor.
    Type: Grant
    Filed: May 2, 2006
    Date of Patent: February 24, 2009
    Assignee: Black & Decker Inc.
    Inventors: J. Michael Weaver, Barbara A. Rose, Mark W. Wood, Daniel U. Goodwin, Hung T. Du, Alan G. Phillips, C. Kerwin Braddock, James A. Patton, Michael A. Lagaly, Patrick G. Barry, Julie L. Jones, Deborah L. Harr
  • Publication number: 20090021090
    Abstract: A power tool has a motor having a stator made by separately forming pole pieces, return path pieces and field coils. The field coils are placed over necks of the pole path pieces and the return path pieces are affixed to the pole pieces. An armature having an outside diameter of at least 0.625 the outside diameter of the stator is placed in the stator. The field coils may be formed so that they extend beyond pole tips of the pole pieces.
    Type: Application
    Filed: March 6, 2006
    Publication date: January 22, 2009
    Applicant: BLACK AND DECKER INC.
    Inventors: Hung T. Du, Earl M. Ortt, Brandon L. Verbrugge, Garrett P. McCormick, Michael A. Zemlock, Eric J. Samuelsen, Kevin M. Hogan, Jiaqi Zhang, Ren Hong Wang, Frank A. Mannarino, Allison A. Smith, Spencer G. Maid, Therese M. Rakosky, Kyle J. Wheaton, Antonios M. Nicolaidis, Shane Ashley Moll, James C. Benton, Eric L. Bernstein
  • Patent number: 7464455
    Abstract: A method for forming an armature for an electric motor includes securing a lamination stack having slots therein on an armature shaft. A commutator is secured on one end of the armature shaft. Magnet wires are wound in the slots in the lamination stack and ends of the magnet wires are secured to the commutator. Plastic is molded around the lamination stack, commutator and magnet wires. Excess plastic is machined off. The magnet wires can have a layer of heat activated adhesive that is activated when the plastic is molded. Slots in the lamination stack can include slot liners formed of thermally conductive plastic. A fan can be formed when the thermally conductive plastic is molded to encapsulate the magnet wires.
    Type: Grant
    Filed: August 10, 2005
    Date of Patent: December 16, 2008
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Richard T. Walter, Michael R. Sell, Joshua F. West
  • Patent number: 7233091
    Abstract: An electric motor has a field assembly, such as a stator, has field coils that are wound to a net shape. Lead wires are brought out from the ends of each field coil. The field coils are insulated. The field coils are assembled with stator core pieces, such as pole pieces and return path pieces, into the stator. The stator core pieces are formed prior to being assembled with the field coils. In an aspect of the invention, the pole pieces and return path pieces are separately formed and then assembled together with the field coils, which have also been separately formed. The pole pieces and return path pieces are formed with mating features that are mated to hold the pole pieces and return path pieces together.
    Type: Grant
    Filed: September 3, 2004
    Date of Patent: June 19, 2007
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Brandon L. Verbrugge, Earl M. Ortt, Michael J. Agnes, Michael A. Zemlok, Robert G. Kusmierski, David J. Smith
  • Patent number: 7215048
    Abstract: An electric motor has an armature and a stators. The armature has a lamination stack having slots therein. An internal shaft extends coaxially through the lamination stack. A plurality of magnet wires are wound in the slots of the lamination stack. A commutator is disposed on the armature shaft to which ends of the magnet wires are electrically coupled. The internal is shaft coupled to an external pinion and bearing journal by an insulated coupling. The magnet wires are at least partially encased in thermally conductive plastic. The magnet wires can have a layer of heat activated adhesive that is activated when the plastic is molded. Slots in the lamination stack can include slot liners formed of thermally conductive plastic. A fan can be formed when the thermally conductive plastic is molded to encapsulate the magnet wires. A power tool has the electric motor.
    Type: Grant
    Filed: August 10, 2005
    Date of Patent: May 8, 2007
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Richard T. Walter, Michael R. Sell, Joshua F. West
  • Patent number: 7211920
    Abstract: An electric motor, power tool using the electric motor, and method of making the electric motor includes making a stator that includes pole portions that have axial lengths less than an axial length of a back iron portion. Alternatively, or in addition, the pole portions have axially opposed ends that decrease in width. Alternatively, or in addition, the pole portions have dovetail features that are received in corresponding recesses of the back iron portion.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: May 1, 2007
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Brandon L. Verbrugge, Earl M. Ortt, Garrett P. McCormick
  • Patent number: 7205696
    Abstract: An electric motor, power tool using the electric motor, and method of making the electric motor includes making a stator that includes pole portions that have axially opposed ends that gradually decrease in width. The pole portions may also have dovetail features that are received in corresponding recesses of the back iron portion.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: April 17, 2007
    Assignee: Black & Decker Inc.
    Inventors: Hung T. Du, Brandon L. Verbrugge, Earl M. Ortt, Garrett P. McCormick
  • Patent number: 7181830
    Abstract: A method of manufacturing a flux ring for an electric motor which has a ring with an anchoring mechanism. The ring is placed inside of a die. A first isotropic magnetic material is added into the die such that the anchoring mechanism secures the first isotropic magnetic material onto the ring. A second anisotropic magnetic material is added into the die adjacent the first isotropic magnetic material. The anchoring mechanism secures the second anisotropic magnetic material onto the ring.
    Type: Grant
    Filed: October 8, 2004
    Date of Patent: February 27, 2007
    Assignee: Black & Decker Inc.
    Inventor: Hung T Du