Patents by Inventor Ronald P. Mackwood

Ronald P. Mackwood 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).

  • Plug for pier hole
    Patent number: 4911586
    Abstract: An inflatable, stretchable plug for obstructing a hole drilled in the ground for a foundation pier comprises a sturdy elastic envelope having an air valve mounted in the wall thereof for connection with outside supply of pressurized air and a handle bonded to upper portion of the envelope for easy removal of the plug from the hole before concrete mixture is poured in to produce the pier.
    Type: Grant
    Filed: January 18, 1989
    Date of Patent: March 27, 1990
    Assignee: Mark R. Kelley
    Inventors: Mark R. Kelley, Ronald P. Mackwood, John M. Broderick