Butterfly valve

Claim 2

A butterfly valve, comprising: a. an annular valve body with an internal wall surrounding and defining a flow passage through the valve, said internal wall having an annular bedgroove for accepting and holding a valve seat rib; b. an annular valve seat of resilient material surrounding the flow passage and positioned against the internal wall of the valve body, said seat having a pair of diametrically opposed and generally semicircular locking ribs extending radially outwardly into the valve body''s bedgroove to prevent distortion of the seat, the ribs having a radial dimension less than the depth of the bedgroove to provide a void between them and the bedgroove for receiving seat material displaced outwardly when the valve is closed; c. a valve disc supported within the seat by shaft means passing through the seat into the valve body; and d. a pair of rigid backup segments intermediate the seat and the valve body where the shaft means passes through the seat, each of said segments being bonded to the seat and having a radial locking rib extending outwardly into the valve body''s bedgroove to prevent movement of the segment and distortion of the seat bonded thereto when the valve is opening or closing, said segments interfitting with the valve seat so that the ribs of the segments and of the seat are coextensive.

Claim 3

A butterfly valve according to claim 1 wherein the backup segments have radially outer arcuate surfaces that extend between the corresponding outer surfaces of the valve seat and the disc-supporting shaft means.

Claim 4

A butterfly valve, including: a. a valve body having a circular internal wall surrounding a flow passage through the body, the internal wall of said valve body being formed with an annular bedgroove centrally located in the internal wall and opposed mounting faces having a peripheral locking groove formed in each face, b. an annular resilient seat positioned against the internal wall of the valve body, said seat having a central annular rib that engages the bedgroove in the valve body, said annular rib on said seat being not as deep as said bedgroove thereby providing a void therebetween to permit expansion of the resilient seat into the void upon rotation of the disc into the closed position, said seat also having a U-shaped cross section formed by radial flanged having locking lugs engaging the peripheral locking grooves in the faces of the valve body, c. a valve disc within the seat, said disc being supported by shaft means passing through the seat into the valve body at its top and bottom, and d. rigid backup segments between the seat and the valve body where the shaft means passes through the seat, said segments being bonded to the seat and having a centrally located rib that engages the annular bedgroove and is coextensive with the seat''S central annular rib to prevent movement of said segments and distortion of the seat bonded thereto during opening or closing of the valve.

Claim 5

A butterfly valve, including: a. a valve body having a circular internal wall surrounding a flow passage through the body, the internal wall of said valve body being formed with an annular bedgroove centrally located in the internal wall and opposed mounting faces having a peripheral locking groove formed in each face, b. an annular resilient seat positioned against the internal wall of the valve body, said seat having a central annular rib that engages the bedgroove in the valve body, said annular rib on said seat being not as deep as said bedgroove thereby providing a void therebetween to permit expansion of the resilient seat into the void upon rotation of the disc into the closed position, said seat also having a U-shaped cross section formed by radial flanged having locking lugs engaging the peripheral locking grooves in the faces of the valve body, c. a valve disc within the seat, said disc being supported by shaft means passing through the seat into the valve body at its top and bottom, and d. rigid backup segments between the seat and the valve body where the shaft means passes through the seat, said segments being bonded to the seat and having a centrally located rib that engages the annular bedgroove and is coextensive with the seat''S central annular rib to prevent movement of said segments and distortion of the seat bonded thereto during opening or closing of the valve.