Patents by Inventor Donald Friedland

Donald Friedland 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).

  • System for controlling density of liquids
    Patent number: 3952761
    Abstract: A system for accurately controlling the density of liquids in a processing system employing a chamber having a finned hydrometer with control activation mechanism floating in a reservoir of continuous sample solution, and having a plurality of chambers so constructed so as to create a liquid stream feeding the zone containing the hydrometer and imparting rotational motion thereto. The height of the hydrometer is sensed as measuring the density of the liquid sample. Appropriate corrections are made to the processing system.
    Type: Grant
    Filed: March 25, 1974
    Date of Patent: April 27, 1976
    Inventor: Donald Friedland