Patents by Inventor Alan L. Litman

Alan L. Litman 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).

  • Wet-dry cementable coupling for plastic pipe
    Patent number: 4281856
    Abstract: A cementable coupling for plastic pipe, that may be employed whether the parts are wet or dry, including cementable fitting and sleeve members that initially provide a dry seal near the end of the pipe, permitting initial drying of the pipe upstream of the dry seal, and enable later cementing of these members together and to the pipe at a location upstream of the dry seal.
    Type: Grant
    Filed: July 28, 1978
    Date of Patent: August 4, 1981
    Inventors: Alan L. Litman, James P. Strode