Patents by Inventor Daniel C. Duggan

Daniel C. Duggan 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).

  • Backflow preventer valve
    Patent number: 4321942
    Abstract: A backflow preventer valve including a housing structure having inlet and outlet ports therethrough for attaching to system conduits, a chamber formed in the housing, a pair of spaced valve seats associated with one of the ports including a space formed between the valve seats, a movable valve assembly including a first member hingedly attached to the valve housing structure for movement in the chamber between a closed position adjacent to the valve seats and an open position angularly related to the closed position, the valve assembly having a clapper portion defined by relatively movable inner and outer members, a flexible valve member including first and second portions and separate members for attaching the flexible valve member respectively to the inner and outer clapper members, the first portion of the flexible valve member being engageable with one of the pair of spaced valve seats in the closed position thereof and the second portion being engageable with the other of the pair of valve seats in the c
    Type: Grant
    Filed: April 8, 1980
    Date of Patent: March 30, 1982
    Inventor: Daniel C. Duggan
  • Backflow preventer valve
    Patent number: 4249568
    Abstract: A backflow preventer valve including a housing structure having inlet and outlet ports therethrough for attaching to system conduits, a chamber formed in the housing, a pair of spaced valve seats associated with one of the ports including an air space formed between the valve seats, and a movable valve assembly including a first member hingedly attached to the valve housing for movement in the chamber between a closed position adjacent to the valve seats and an open position angularly related to the closed position, and the valve assembly having a clapper portion defined by relatively movable inner and outer members, a flexible valve member including first and second portions and separate members for attaching the flexible valve member respectively to the inner and outer clapper members, the first portion of the flexible valve member being engageable with one of the pair of spaced valve seats in the closed position thereof and the second portion being engageable with the other of the pair of valve seats in th
    Type: Grant
    Filed: October 2, 1978
    Date of Patent: February 10, 1981
    Inventor: Daniel C. Duggan