Patents by Inventor David Erfer

David Erfer 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).

  • Writing instrument with self-closure
    Patent number: 4218154
    Abstract: A writing instrument includes a self-closure provided by a plurality of segment members which, when operably disposed, form a protective enclosure for the writing tip and, when not operably disposed, retract within the barrel of the instrument.
    Type: Grant
    Filed: June 26, 1978
    Date of Patent: August 19, 1980
    Inventor: David Erfer