Patents by Inventor Marvin E. Holmgren

Marvin E. Holmgren 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: 4047412
    Abstract: A method of making a pipe fitting havin three or more legs arranged in any desired shape by deforming a malleable metal tube substantially filled with a constant volume filler material in a single step without the need for secondary bending while maintaining the filler material at constant volume to provide a fitting wherein the variation in wall thickness is less than about 10%.
    Type: Grant
    Filed: November 15, 1976
    Date of Patent: September 13, 1977
    Assignee: Elkhart Products Corporation
    Inventor: Marvin E. Holmgren
  • Patent number: 3944453
    Abstract: An improved hose construction and method of forming the same wherein a reinforcement layer is bonded to a thermoplastic core by a solventless bonding layer defining an inner thermal weld portion substantially autogenous with the outer surface portion of the core tube and an outer portion mechanically interlocked with the confronting inner portion of the reinforcement layer.The bonding layer is thermally formed to be autogenous with the outer surface portion of the core tube and may include an added layer of thermoplastic material which is concurrently fused to define the fused bonding layer. The added layer is compatible with the core tube outer surface portion and is preferably formed of similar thermoplastic material. The reinforcement layer is wrapped about the core tube under tension to provide an embedment thereof in the bonding layer to effect a positive mechanical interlocking therebetween.
    Type: Grant
    Filed: July 5, 1974
    Date of Patent: March 16, 1976
    Assignee: Imperial-Eastman Corporation
    Inventors: Anil H. Chudgar, Richard L. Fischer, Marvin E. Holmgren