Patents by Inventor Donald G. McKenzie

Donald G. McKenzie 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).

  • Patent number: 4842016
    Abstract: A two position four-way switching valve has two inputs and two outputs. In one position of the valve, each input is connected to a defined one of the outputs, while in a second position the outputs are reversed. In a specific embodiment, the valve includes an inner cylindrical member enclosed within an outer casing having an opening forming an outlet. The other outlet and the two inlets are formed by tubes that extend inwardly through the casing and communicate with ports in the inner cylindrical member. The ports include first, second and third ports are spaced axially along the cylindrical member. Fluid entering through the inlets is routed to the outlets by plug-type valves including seals carried by an axially movable stem extending through the cylindrical member.
    Type: Grant
    Filed: February 22, 1988
    Date of Patent: June 27, 1989
    Assignee: Delta Projects Inc.
    Inventor: Donald G. McKenzie