Patents by Inventor Eli Blumenau

Eli Blumenau 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: 5123776
    Abstract: A manhole cover comprises a top having a top surface and an edge portion, a depending portion having a sidewall and a bottom surface, and an interior chamber. The manhole cover is fabricated from a first material, while the interior chamber is at least partially filled with a second material. The manhole cover preferably includes recessed handles which are recessed into the top and extend downwardly through the bottom surface. Cooperative engagement means in the form of inter-fitting indentations and protuberances are provided in the top surface and the bottom surface respectively. The bottom surface includes a first surface portion which includes a peripheral edge portion and a bracing portion. The bracing portion includes a plurality of brace members each of which have a lower brace surface and a brace sidewall.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: June 23, 1992
    Assignee: Advanced Drainage Systems, Inc.
    Inventors: Timothy J. Lang, Mark Stuhlreyer, Eli Blumenau