Patents by Inventor Robert Lewis Smith

Robert Lewis Smith 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).

  • Piston valve
    Patent number: 4011889
    Abstract: A valve having separate closures for its inlet and its outlet respectively comprises a housing having the inlet in an elongated tubular wall and the outlet at an annular valve seat. A piston constituting one closure is movable coaxially within said wall so as to open and close the outlet. A sleeve constituting another closure is movable coaxially over the piston and within said wall so as to open and close the inlet. The piston and the sleeve are associated for interdependent movement.
    Type: Grant
    Filed: December 11, 1975
    Date of Patent: March 15, 1977
    Assignee: Chemetron Corporation
    Inventor: Robert Lewis Smith