Patents by Inventor Mark R. Corbin

Mark R. Corbin 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).

  • Patent number: 5229024
    Abstract: The invention relates to seals on equipment used to make concrete pipe. Such equipment includes two generally vertical cylindrical surfaces, a core and a mold, with upper and lower end forming rings. The lower end forming ring, a pallet, has inner and outer vertical surfaces. Seals of the present invention are formed by using two hollow tubes of soft rubber. The tubes are housed in lower portions of the core and the mold so that they are in alignment with the inner and outer surfaces of the pallet. The tubes are pressurized into tight engagement with the pallet to prevent the outward flow of slurry from the space between the core and the mold.
    Type: Grant
    Filed: July 19, 1991
    Date of Patent: July 20, 1993
    Assignee: International Pipe Machinery Corp.
    Inventor: Mark R. Corbin