Patents by Inventor David B. Crafts

David B. Crafts 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).

  • Method and apparatus for replacing underground pipe
    Patent number: 11009174
    Abstract: A pipe bursting system and method, and components thereof, are described wherein a bursting head assembly pulled by a cable employs a relatively small pneumatic impactor (hammer) and a relatively large cable tension to impose a cyclical stress on the pipe being burst to cause fatigue failure of the pipe, resulting in lower size and power requirements, and higher efficiency for a given set of job requirements.
    Type: Grant
    Filed: February 12, 2020
    Date of Patent: May 18, 2021
    Inventors: Robert Ward Carter, David B Crafts, Maxwell Frank Darrow
  • METHOD AND APPARATUS FOR REPLACING UNDERGROUND PIPE
    Publication number: 20200284389
    Abstract: A pipe bursting system and method, and components thereof, are described wherein a bursting head assembly pulled by a cable employs a relatively small pneumatic impactor (hammer) and a relatively large cable tension to impose a cyclical stress on the pipe being burst to cause fatigue failure of the pipe, resulting in lower size and power requirements, and higher efficiency for a given set of job requirements.
    Type: Application
    Filed: February 12, 2020
    Publication date: September 10, 2020
    Inventors: Robert Ward Carter, David B. Crafts, Maxwell Frank Darrow
  • Method and apparatus for replacing underground pipe
    Patent number: 10598306
    Abstract: A pipe bursting system and method are described wherein a bursting head pulled by a cable employs a relatively small pneumatic hammer and a relatively large cable tension to impose a cyclical hoop stress on the pipe being burst to cause fatigue failure of the pipe, resulting in lower size and power requirements, and higher efficiency for a given set of job requirements.
    Type: Grant
    Filed: February 22, 2018
    Date of Patent: March 24, 2020
    Inventors: Robert Ward Carter, David B Crafts, Maxwell Frank Darrow
  • METHOD AND APPARATUS FOR REPLACING UNDERGROUND PIPE
    Publication number: 20180245726
    Abstract: A pipe bursting system and method are described wherein a bursting head pulled by a cable employs a relatively small pneumatic hammer and a relatively large cable tension to impose a cyclical hoop stress on the pipe being burst to cause fatigue failure of the pipe, resulting in lower size and power requirements, and higher efficiency for a given set of job requirements.
    Type: Application
    Filed: February 22, 2018
    Publication date: August 30, 2018
    Inventors: Robert Ward Carter, David B. Crafts, Maxwell Frank Darrow
  • Apparatus for removing a surface layer from a floor or the like
    Patent number: 5641206
    Abstract: An apparatus for removing at least one surface layer from a floor or the like comprises a machine body having a longitudinal axis, rear weight-bearing guide wheels, and a front weight-bearing wheel. A front weight-bearing scraping apparatus is pivotable with respect to the machine body by a cylinder located between the machine body and the front weight-bearing scraping apparatus.
    Type: Grant
    Filed: August 17, 1995
    Date of Patent: June 24, 1997
    Assignee: Innovatech Products & Equipment Co.
    Inventor: David B. Craft