Patents by Inventor Denise M. Caldwell

Denise M. Caldwell 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).

  • Fluid driven pump with improved exhaust port arrangement
    Patent number: 6962487
    Abstract: A fluid driven pump. One embodiment of the fluid driven pump may include first and second diaphragms supported within a housing assembly such that first and second fluidtight expansion chambers are defined within the housing. The pump may have a first exhaust valve movably supported in a first exhaust valve cavity in fluid communication with the first expansion chamber and an exhaust port in the housing assembly. In addition, the pump may have a second exhaust valve movably supported in a second exhaust valve cavity in fluid communication with the second expansion chamber and the exhaust port. A flow control system may be supported by the housing assembly and be couplable to a source of pressurized control fluid.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: November 8, 2005
    Assignee: Versa-Matic Tool, Inc.
    Inventor: Denise M. Caldwell