Patents by Inventor Roberto Viazzi

Roberto Viazzi 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).

  • Sliding stem seal, particularly for valve stems
    Patent number: 4993379
    Abstract: A seal for the stem of an internal combustion engine intake or exhaust valve; which seal presents a first portion mounted integral with an element supporting the stem; and a second portion inside which are formed two annular lips cooperating in contacting manner with the stem and defining, together and with the stem, an annular chamber inside which part of the lubricating oil supplied when the engine is running is trapped when the engine is idle, thus preventing the sealing lips from drying and sticking to the valve stem.
    Type: Grant
    Filed: November 2, 1989
    Date of Patent: February 19, 1991
    Assignee: RFT S.p.A.
    Inventor: Roberto Viazzi