Fuse assembly

Claim 2

A fuse assembly for use in association with a fluid conduit to prevent excessive fluid flow through the conduit, said fuse assembly comprising a fuse body adapted to be connected with the conduit, valve means disposed in said fuse body for blocking fluid flow through said fuse body in response to the occurrence of a predetermined pressure differential across said valve means, said valve means being movable relative to the fuse body under the influence of the predetermined pressure differential from an open position enabling fluid to flow through said fuse body to a closed position blocking fluid flow through said fuse body, and spring means disposed in said fuse body for biasing said valve means toward the open position, said fuse body including a first stop ring which circumscribes said valve means, said valve means including a second stop ring disposed downstream of said first stop ring and having an external diameter which is greater than an internal diameter of said first stop ring, said first and second stop rings being urged into abutting engagement with each other under the influence of said spring means when said valve means is in the open position, said second stop ring being disposed downstream of said first stop ring when said valve means is in the closed condition, said valve means including resilient means for enabling said second stop ring to be radially compressed to an external diameter which is no greater than the internal diameter of said first stop ring to enable said second stop ring to be moved through said first stop ring from a position upstream of said first stop ring to a position downstream of said first stop ring during assembly of the fuse assembly.

Claim 3

A fuse assembly for use in associate with a fluid conduit to prevent excessive fluid flow through the conduit, said fuse assembly comprising a fuse body adapted to be connected with the conduit, valve means disposed in said fuse body for blocking fluid flow through said fuse body in response to the occurrence of a predetermined pressure differential across said valve means, said valve means being movable relative to the fuse body under the influence of the predetermined pressure differential from an open position enabling fluid to flow through said fuse body to a closed position blocking fluid flow through said fuse body, and spring means disposed in said fuse body for biasing said valve means toward the open position, said valve means including a hollow valve body having a longitudinally extending side wall, means defining an inlet opening in said side wall for enabling fluid to flow transversely through side wall from the exterior to the interior of said hollow valve body when said valve means is in the open position and a valve head disposed on an upstream end portion of said valve body and projecting transversely outwardly of said longitudinally extending side wall, said fuse body including means for defining a valve seat circumscribing said valve body, said valve body being spaced from said valve seat when said valve means is in the open position to enable fluid to flow around said valve head and through said inlet opening and hollow valve body to a location downstream of said valve means, said valve head being disposed in abutting engagement with said valve seat when said valve means is in the closed position to block fluid flow around said valve head to said inlet opening.

Claim 4

A fuse assembly for use in associate with a fluid conduit to prevent excessive fluid flow through the conduit, said fuse assembly comprising a fuse body adapted to be connected with the conduit, valve means disposed in said fuse body for blocking fluid flow through said fuse body in response to the occurrence of a predetermined pressure differential across said valve means, said valve means being movable relative to the fuse body under the influence of the predetermined pressure differential from an open position enabling fluid to flow through said fuse body to a closed position blocking fluid flow through said fuse body, and spring means disposed in said fuse body for biasing said valve means toward the open position, said valve means including a hollow valve body having a longitudinally extending side wall, means defining an inlet opening in said side wall for enabling fluid to flow transversely through side wall from the exterior to the interior of said hollow valve body when said valve means is in the open position and a valve head disposed on an upstream end portion of said valve body and projecting transversely outwardly of said longitudinally extending side wall, said fuse body including means for defining a valve seat circumscribing said valve body, said valve body being spaced from said valve seat when said valve means is in the open position to enable fluid to flow around said valve head and through said inlet opening and hollow valve body to a location downstream of said valve means, said valve head being disposed in abutting engagement with said valve seat when said valve means is in the closed position to block fluid flow around said valve head to said inlet opening.

Claim 5

A fuse assembly as set forth in claim 1 further including bleed means for enabling fluid to flow at a very low rate from the upstream side of said valve means to the downstream side of said valve means when said valve means is in the closed position to tend to reduce the pressure differential across said valve means and enable saiD valve means to be moved from the closed position to the open position under the influence of said spring means.

Claim 6

A fuse assembly as set forth in claim 2 wherein said spring means includes a coil spring circumscribing said side wall of said valve body and extending between said valve head and said fuse body for urging said valve means to the open position.

Claim 7

A fuse assembly as set forth in claim 2 wherein said fuse body further includes a first stop ring which circumscribes said valve means, said valve means including a second stop ring disposed downstream of said first stop ring and having an external diameter which is greater than an internal diameter of said first stop ring, said first and second stop rings being urged into abutting engagement with each other under the influence of said spring means when said valve means is in the open position, said second stop ring being disposed downstream of said first stop ring when said valve means is in the closed condition.

Claim 8

A fuse assembly as set forth in claim 5 wherein said valve means includes resilient means for enabling said second stop ring to be radially compressed to an external diameter which is no greater than the internal diameter of said first stop ring to enable said second stop ring to be moved through said first stop ring from a position upstream of said first stop ring to a position downstream of said first stop ring during assembly of the fuse assembly.

Claim 9

A fuse assembly as set forth in claim 2 further including passage means extending through said valve head for enabling fluid to flow through said valve head when said valve means is in the closed position to tend to reduce a pressure differential across said valve head and enable said valve means to move from the closed position to the open position under the influence of said spring means.

Claim 10

A fuse assembly for use in association with a fluid conduit to prevent excessive fluid flow through the conduit, said fuse assembly comprising a tubular fuse body member defining a longitudinally extending valve chamber having an inlet at an upstream end portion of said fuse body member and an outlet at a downstream end portion of said fuse body member, said valve chamber including an inlet portion extending downstream from said inlet and having a first cross sectional area in a first transverse plane, an intermediate portion extending downstream from said inlet portion and having a second cross sectional area which is smaller than said first cross sectional area in a second transverse plane which is disposed downstream of and extends parallel to said first transverse plane, surface means for forming a valve seat adjacent to the junction between said inlet and intermediate portions, a stop element at a downstream end of said intermediate portion and having a third cross sectional area which is smaller than said second cross area in a third transverse plane which is disposed downstream of and extends parallel to said second transverse plane, and an outlet portion extending downstream from said stop element to said outlet and having a fourth cross sectional area which is larger than said third cross sectional area in a fourth plane which is disposed downstream of and extends parallel to said third plane, said fuse assembly further including valve means disposed in said valve chamber and movable from an open position enabling fluid to flow through said fuse body to a closed position blocking fluid flow through said fuse body in response to a predetermined pressure differential across said valve means, said valve means including a head portion disposed in said inlet portion of said valve chamber and having a transverse cross sectional area in a plane extending parallel to said first plane which is smaller than said first cross sectional area and larger than said second cross sectional area, said valve head portion being disposed upstream of said valve seat when said valve means is in the open position and being disposed in sealing engagement with said valVe seat when said valve means is in the closed position, a valve body connected with and extending downstream of said head portion through said stop element and intermediate portion of said valve chamber and having a cross sectional area in a plane extending parallel to said second plane which is smaller than said third cross sectional area, and stop means connected with a downstream end portion of said valve body and having a cross sectional area in a plane extending parallel to said second plane which is larger than said third cross sectional area and smaller than said fourth cross sectional area, said stop means being disposed in abutting engagement with a downstream surface of said stop element when said valve means is in the open position and being spaced from said stop element when said valve means is in the closed position, said valve body including a tubular wall connected with said head portion and defining a longitudinally extending central passage which is connected in fluid communication with said outlet portion and a transversely extending inlet opening to said central passage, said inlet opening being at least partially disposed in said inlet portion of said valve chamber when said valve means is disposed in the open position to enable fluid to flow from said inlet portion of said valve chamber through said inlet opening and central passage to said outlet portion of said valve chamber, said inlet opening being disposed in said intermediate portion of said valve chamber when said valve means is in the closed position to block fluid flow through said inlet opening by sealing engagement of said head portion with said valve seat.

Claim 11

A fuse assembly for use in association with a fluid conduit to prevent excessive fluid flow through the conduit, said fuse assembly comprising a tubular fuse body member defining a longitudinally extending valve chamber having an inlet at an upstream end portion of said fuse body member and an outlet at a downstream end portion of said fuse body member, said valve chamber including an inlet portion extending downstream from said inlet and having a first cross sectional area in a first transverse plane, an intermediate portion extending downstream from said inlet portion and having a second cross sectional area which is smaller than said first cross sectional area in a second transverse plane which is disposed downstream of and extends parallel to said first transverse plane, surface means for forming a valve seat adjacent to the junction between said inlet and intermediate portions, a stop element at a downstream end of said intermediate portion and having a third cross sectional area which is smaller than said second cross area in a third transverse plane which is disposed downstream of and extends parallel to said second transverse plane, and an outlet portion extending downstream from said stop element to said outlet and having a fourth cross sectional area which is larger than said third cross sectional area in a fourth plane which is disposed downstream of and extends parallel to said third plane, said fuse assembly further including valve means disposed in said valve chamber and movable from an open position enabling fluid to flow through said fuse body to a closed position blocking fluid flow through said fuse body in response to a predetermined pressure differential across said valve means, said valve means including a head portion disposed in said inlet portion of said valve chamber and having a transverse cross sectional area in a plane extending parallel to said first plane which is smaller than said first cross sectional area and larger than said second cross sectional area, said valve head portion being disposed upstream of said valve seat when said valve means is in the open position and being disposed in sealing engagement with said valVe seat when said valve means is in the closed position, a valve body connected with and extending downstream of said head portion through said stop element and intermediate portion of said valve chamber and having a cross sectional area in a plane extending parallel to said second plane which is smaller than said third cross sectional area, and stop means connected with a downstream end portion of said valve body and having a cross sectional area in a plane extending parallel to said second plane which is larger than said third cross sectional area and smaller than said fourth cross sectional area, said stop means being disposed in abutting engagement with a downstream surface of said stop element when said valve means is in the open position and being spaced from said stop element when said valve means is in the closed position, said valve body including a tubular wall connected with said head portion and defining a longitudinally extending central passage which is connected in fluid communication with said outlet portion and a transversely extending inlet opening to said central passage, said inlet opening being at least partially disposed in said inlet portion of said valve chamber when said valve means is disposed in the open position to enable fluid to flow from said inlet portion of said valve chamber through said inlet opening and central passage to said outlet portion of said valve chamber, said inlet opening being disposed in said intermediate portion of said valve chamber when said valve means is in the closed position to block fluid flow through said inlet opening by sealing engagement of said head portion with said valve seat.

Claim 12

A fuse assembly as set forth in claim 8 further including spring means circumscribing said valve body and extending between said head portion of said valve means and said stop element for urging said valve means to the open position.

Claim 13

A fuse assembly as set forth in claim 9 wherein said valve body includes resilient means for enabling said stop means to be compressed inwardly to a cross-sectional area which is at most equal to said third cross-sectional area to facilitate assembling of said fuse assembly.

Claim 14

A fuse assembly as set forth in claim 9 further including passage means extending through said heat portion for enabling fluid to flow from ustream of said head portion through said passage means and central passage to said outlet portion of said valve chamber to tend to reduce the pressure differential across said valve means and enable said spring means to move said valve means to the open position when said valve means is in the closed position.