Patents by Inventor Howell Allen Hammond

Howell Allen Hammond 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).

  • Cyanoethyl-containing blocked development restrainers
    Patent number: 4009029
    Abstract: Photographic elements are disclosed which contain a blocked development restrainer which is designed to provide timely release of a development restrainer when the photographic element is processed with an alkaline processing composition. The photographic elements are especially useful in image-transfer film units where the blocked development restrainers will permit initial development to occur and, upon cleavage, will substantially restrain further development.
    Type: Grant
    Filed: June 20, 1975
    Date of Patent: February 22, 1977
    Assignee: Eastman Kodak Company
    Inventors: Howell Allen Hammond, Wilbert Jeptha Humphlett, Ilmari Fritiof Salminen