Patents by Inventor John C. Caldwell

John C. Caldwell 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).

  • Automatic liquid mixing device
    Patent number: 4018685
    Abstract: A device for mixing a plurality of liquid components in preselected proportions to form a mixture of the liquid components. The device includes a separate liquid component storage reservoir for each liquid component, a pump, means to successively connect the suction of the pump to each reservoir, and proportioning means to control the switching of the pump suction to each storage reservoir for a short, controlled time interval during each of a series of operating cycles which are repeated throughout the mixing operations.
    Type: Grant
    Filed: October 24, 1975
    Date of Patent: April 19, 1977
    Assignee: Union Oil Company of California
    Inventors: Dennis L. Saunders, John C. Caldwell