Patents by Inventor David S. Krafsur

David S. Krafsur 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: 7219447
    Abstract: A sole assembly for an article of footwear comprises a midsole, a sole having a heel region, and a first wave spring disposed within a vacuity located within the heel region. The wave spring includes a top surface and a bottom surface. A plate, resting upon the top surface of the wave spring, is unsecured to the midsole and sized to permit movement within the vacuity along with the wave spring responsive to a rolling footstrike.
    Type: Grant
    Filed: January 31, 2005
    Date of Patent: May 22, 2007
    Inventors: Francis E. LeVert, David S. Krafsur
  • Patent number: 7159338
    Abstract: A fluid flow system for a spring-cushioned shoe is disclosed. The sole of the shoe includes a vacuity, a spring disposed within the vacuity, and a fluid passageway in fluid communication with the vacuity. The fluid flow passageway allows fluid, such as air, to escape the vacuity when the volume of the vacuity is reduced during a foot strike.
    Type: Grant
    Filed: January 31, 2005
    Date of Patent: January 9, 2007
    Inventors: Francis E. LeVert, David S. Krafsur
  • Patent number: 6886274
    Abstract: A sole assembly for an article of footwear comprises a sole having a heel region and a ball region. A first multi-turn wave spring disposed within the sole comprises an upper turn and a lower turn. The upper turn is in pivotal contact with the lower turn to define a first side and an opposing second side of the multi-turn wave spring. Compression of the first side causes expansion pressure on the second side and compression of the second side causes expansion pressure on the first side to provide cushioning and energy return responsive to a rolling footstrike.
    Type: Grant
    Filed: February 20, 2003
    Date of Patent: May 3, 2005
    Assignee: Shoe Spring, Inc.
    Inventors: David S. Krafsur, Francis E. LeVert
  • Patent number: 6865824
    Abstract: A fluid flow system for a spring-cushioned shoe is disclosed. The sole of the shoe includes a vacuity, a spring disposed within the vacuity, and a fluid passageway in fluid communication with the vacuity. The fluid flow passageway allows fluid, such as air, to escape the vacuity when the volume of the vacuity is reduced during a foot strike.
    Type: Grant
    Filed: May 14, 2003
    Date of Patent: March 15, 2005
    Inventors: Francis E. Levert, David S. Krafsur
  • Patent number: 6665957
    Abstract: A fluid flow system for a spring-cushioned shoe is disclosed. The sole of the shoe includes a vacuity, a spring disposed within the vacuity, and a fluid passageway in fluid communication with the vacuity. The fluid flow passageway allows fluid, such as air, to escape the vacuity when the volume of the vacuity is reduced during a foot strike.
    Type: Grant
    Filed: October 18, 2001
    Date of Patent: December 23, 2003
    Assignee: Shoe Spring, Inc.
    Inventors: Francis E. Levert, David S. Krafsur
  • Publication number: 20030192201
    Abstract: A fluid flow system for a spring-cushioned shoe is disclosed. The sole of the shoe includes a vacuity, a spring disposed within the vacuity, and a fluid passageway in fluid communication with the vacuity. The fluid flow passageway allows fluid, such as air, to escape the vacuity when the volume of the vacuity is reduced during a foot strike.
    Type: Application
    Filed: May 14, 2003
    Publication date: October 16, 2003
    Inventors: Francise E. Levert, David S. Krafsur
  • Publication number: 20030163933
    Abstract: A sole assembly for an article of footwear comprises a sole having a heel region and a ball region. A first multi-turn wave spring disposed within the sole comprises an upper turn and a lower turn. The upper turn is in pivotal contact with the lower turn to define a first side and an opposing second side of the multi-turn wave spring. Compression of the first side causes expansion pressure on the second side and compression of the second side causes expansion pressure on the first side to provide cushioning and energy return responsive to a rolling footstrike.
    Type: Application
    Filed: February 20, 2003
    Publication date: September 4, 2003
    Applicant: Shoe Spring, Inc.
    Inventors: David S. Krafsur, Francis E. LeVert
  • Publication number: 20020088142
    Abstract: A fluid flow system for a spring-cushioned shoe is disclosed. The sole of the shoe includes a vacuity, a spring disposed within the vacuity, and a fluid passageway in fluid communication with the vacuity. The fluid flow passageway allows fluid, such as air, to escape the vacuity when the volume of the vacuity is reduced during a foot strike.
    Type: Application
    Filed: October 18, 2001
    Publication date: July 11, 2002
    Inventors: Francis E. Levert, David S. Krafsur
  • Patent number: 6353656
    Abstract: A radioisotope based x-ray residual stress analysis apparatus having a shielded, monoenergetic radioisotopic source to emit x rays for measurement of the stress state of a polycrystalline material. The isotropic source is selected from spontaneously emissive radioisotopes emitting photons in the 5-100 keV energy range. The emissions of the source assembly are measured using either a conventional, solid-state, position sensitive detector or a gas filled position sensitive proportional counter (PSPC). In addition to normal residual stress analysis, the use of a PSPC allows the identification of characteristic photons emitted by particular isotopes to identify trace elements within a sample. As a result of the minimal shielding required for the source assembly and the small size of the isotropic source, the x-ray residual stress analysis apparatus of the present invention is uniquely suited to be configured with an area detector.
    Type: Grant
    Filed: July 22, 1999
    Date of Patent: March 5, 2002
    Assignee: Technology for Energy Corporation
    Inventors: Francis E. LeVert, David S. Krafsur, E. Beth Pardue, V. Carol Bailey
  • Publication number: 20010049888
    Abstract: A spring cushioned shoe is disclosed. The shoe includes a sole assembly that has a first spring disposed within a vacuity in the heel portion of the assembly, and a second spring disposed within a vacuity in the ball portion of the assembly. The springs are, e.g., wave springs that extend vertically from the upper to the lower internal boundaries of the vacuities.
    Type: Application
    Filed: July 10, 2001
    Publication date: December 13, 2001
    Inventors: David S. Krafsur, Francis E. LeVert
  • Patent number: 6282814
    Abstract: A spring cushioned shoe is disclosed. The shoe includes a sole assembly that has a first spring disposed within a vacuity in the heel portion of the assembly, and a second spring disposed within a vacuity in the ball portion of the assembly. The springs are, e.g., wave springs that extend vertically from the upper to the lower internal boundaries of the vacuities.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: September 4, 2001
    Assignee: Shoe Spring, Inc.
    Inventors: David S. Krafsur, Francis E. LeVert