Patents by Inventor Mark S. Sisco

Mark S. Sisco 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: 5531541
    Abstract: A manhole cover is seated on a flange in a frame from which depends a skirt forming an access opening to a cavity. A cover lifting mechanism external the access opening includes an arm secured to the cover and a tubular cylinder fixed to the skirt, the cylinder including internal aligned journal bushings. A tubular shaft depends from the arm into the journal and axially displaces and rotates about the journal axis. The shaft has an axially extending central bore with a threaded portion. A threaded rod in the central bore rotates about the shaft axis and is captured to a bearing secured to the cylinder lower end. The rod upper end is squared to receive a socket wrench for manually turning the rod with a mechanical advantage which lifts the shaft, the arm and thus the cover out of its seat. Once lifted, the cover is readily rotated away from the access opening by rotating the shaft in the journal while the threads remain engaged.
    Type: Grant
    Filed: March 22, 1995
    Date of Patent: July 2, 1996
    Assignee: Fairfield Industries
    Inventors: Daniel S. Clover, Mark S. Sisco