Patents by Inventor Robert H. Ritzie

Robert H. Ritzie 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).

  • Mechanical seal assembly with flushing means
    Patent number: 4130287
    Abstract: A reliable, long-wearing mechanical seal for a shaft entering a vessel is prepared employing two bellows seals in tandem and providing a path for a flushing fluid between the bellows seals.
    Type: Grant
    Filed: November 23, 1977
    Date of Patent: December 19, 1978
    Assignee: The Dow Chemical Company
    Inventor: Robert H. Ritzie
  • Injection molding machine and method of operation thereof
    Patent number: 3985349
    Abstract: Improved mixing is obtained in a reciprocating screw injection molding machine by providing an axial passage within the screw. The passage provides communication between the discharge end of the screw and an upstream location. A valve is disposed within the passage to provide selective communication. Recirculation of melt within the passage and about the screw provides improved mixing.
    Type: Grant
    Filed: March 6, 1975
    Date of Patent: October 12, 1976
    Assignee: The Dow Chemical Company
    Inventor: Robert H. Ritzie