Patents by Inventor David A. Merrell

David A. Merrell 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).

  • Expanding helical seal for pistons and the like
    Patent number: 4333661
    Abstract: A seal 34 formed of a resilient helical coil 42 which is stressed at its small end to form a stationary seal in its groove 36 and stressed to unwind at its large end 44 to form a dynamic seal against the cylinder wall 22. A helical coil 56 of low friction material can be interleaved to supply dry lubricant.
    Type: Grant
    Filed: December 5, 1980
    Date of Patent: June 8, 1982
    Assignee: Hughes Aircraft Company
    Inventor: David A. Merrell