Patents by Inventor Frederick R. Duffield

Frederick R. Duffield 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).

  • Reusable type hose end fitting
    Patent number: 4400021
    Abstract: A reusable type hose end fitting comprising a through-bored stem portion and a ferrule portion which is removably screw-coupled to the stem portion. The stem portion has a first zone which is formed with a male screw thread and a second zone which locates within the bore of a hose. The ferrule portion has a first zone which is formed with a female thread for engagement with the male thread of the stem portion and a second zone which locates about the second zone of the stem portion to define a generally annular space in which an end portion of the hose locates when the fitting is assembled to the hose. The second zone of the stem portion is formed with four tapered regions and with cylindrical lands which separate adjacent ones of the tapered regions.
    Type: Grant
    Filed: August 6, 1981
    Date of Patent: August 23, 1983
    Assignee: Frederick Duffield Pty. Limited
    Inventor: Frederick R. Duffield