Patents by Inventor William W. Hargreaves

William W. Hargreaves 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).

  • Photographic film developer
    Patent number: 4208119
    Abstract: A developer unit for sheet film in which individual sheets are moved through processing tanks by holders moved by an elevator from tank to tank and thence the sheets are disposed from the developer, the holders are recovered in the developer after disposal of the sheet film and are conveyed via a holder store to a film reception station where sheets are loaded individually with the holders for processing.
    Type: Grant
    Filed: September 27, 1978
    Date of Patent: June 17, 1980
    Inventors: Harry A. H. Spence-Bate, William W. Hargreaves