Patents by Inventor Alan D. Bull

Alan D. Bull 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).

  • Apparatus for controlling addition of replenishment solution to a photographic processor
    Patent number: RE30123
    Abstract: An apparatus for controlling make-up and addition of replenishment solution to a photographic processor, having one or more reservoirs and metering pumps for selecting make-up solution concentrates, and electronic controls for determining the volume of replenishment solution. Replenishment can be accomplished taking into consideration all of the operating variables such as film size, replenishment rate, and percent exposure, as well as the cumulative effect of any additions and aerial oxidation of the solution while not in use.
    Type: Grant
    Filed: July 6, 1976
    Date of Patent: October 23, 1979
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: John A. Crowell, Alan D. Bull