Patents by Inventor Douglas W. Hartford

Douglas W. Hartford 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).

  • Process for extruding low density foam using water blowing agent
    Patent number: 5788889
    Abstract: In a process for extruding a low density foam, a foamable thermoplastic elastomer such as a thermoplastic rubber is selected. The selected thermoplastic elastomer is then fed into a heated extruder barrel where it is compressed and melted by the action of a screw. A blowing agent consisting of water is introduced into the melted thermoplastic elastomer. The melted thermoplastic elastomer and the water are thoroughly mixed and then cooled to a uniform, predetermined temperature. The mixture is then forced through a die to form an extruded foam profile.
    Type: Grant
    Filed: March 3, 1997
    Date of Patent: August 4, 1998
    Assignee: Amesbury Group, Inc.
    Inventors: Alan J. DeMello, Douglas W. Hartford, Peter E. Mertinooke, Dan C. Muessel, Louis Halberstadt
  • Process for extruding low density foam using water as a blowing agent
    Patent number: 5607629
    Abstract: In a process for extruding a low density foam, a foamable thermoplastic elastomer such as a thermoplastic rubber is selected. The selected thermoplastic elastomer is then fed into a heated extruder barrel where it is compressed and melted by the action of a screw. A blowing agent consisting of water is introduced into the melted thermoplastic elastomer. The melted thermoplastic elastomer and the water are thoroughly mixed and then cooled to a uniform, predetermined temperature. The mixture is then forced through a die to form an extruded foam profile.
    Type: Grant
    Filed: June 7, 1994
    Date of Patent: March 4, 1997
    Assignee: Amesbury Group Inc.
    Inventors: Alan J. DeMello, Douglas W. Hartford, Peter E. Mertinooke, Dan C. Muessel, Louis Halberstadt