Breakaway pipe coupling with automatic shutoff
A pipe coupling for use with a fire hydrant or like has automatic shut-off features in the event of breakage of the fire hydrant. The breakaway pipe coupling includes an extension join to a valve body with a flow passage way extending through the extension and valve body. A shut-off valve is moveably mounted to the extension and is bois for movement toward a valve seat located in the valve body. A wedge extends between the extension and the shut-off valve, wedging the shut-off valve in a open position away from the valve seat. Extension and valve are separably joined together in that the extension includes a frangible portion which severs upon application of an impact force to pipe coupling. This allows the wedge to become dislodged, with the shut-off valve being urged in a position towards the valve seat.
1 . A pipe coupling having automatic shutoff, comprising: an extension including an extension body with opposed first and second ends, and a flow passageway defined between the first and second ends of said extension body; a valve including a valve body with opposed first and second ends, a valve seat associated with said valve body, and a flow passageway defined between the first and second ends of said valve body; a shutoff valve movably mounted to said valve body for movement toward and away from said valve seat; a bias member between said valve body and said shutoff valve, urging said shutoff valve toward said valve seat; a holding member having opposed first and second ends, extending between said extension body and said shutoff valve, holding said shutoff valve in an open position away from said valve seat; joining means joining said extension body to said valve body so as to bring the flow passageways of said extension body and said valve body into flow communication with one another; and separation means associated with said pipe coupling to separate the joinder of the valve body to at least a portion of the extension body upon application of an impact force to said pipe coupling so as to allow said holding member to move from a position between said extension body and said shutoff valve, allowing said shutoff valve to move toward said valve seat for seating engagement therewith, at least substantially blocking flow through said valve body.
2 . The pipe coupling of claim 1 wherein one end of said holding member is joined to said extension body.
3 . The pipe coupling of claim 1 wherein one end of said holding member is threaded and said extension body defines a threaded passageway which threading engages the holding member.
4 . The pipe coupling of claim 1 wherein said shutoff valve includes a contact surface engaging said holding member, wedging said holding member between said extension body and said shutoff valve.
5 . The pipe coupling of claim 1 wherein said shutoff valve includes a top wall with opposed first and second surfaces surrounded by an outer side wall, the side wall and the first surface cooperating to define a seating surface of the shutoff valve.
6 . The pipe coupling of claim 5 wherein said first surface and said side wall cooperate to define a concave recess.
7 . The pipe coupling of claim 6 wherein, with movement of said shutoff valve toward said valve seat, said concave recess faces the direction of flow through said pipe coupling, so that a flow force urges said shutoff valve into contact with said valve seat.
8 . The pipe coupling of claim 6 further comprising a cup member on said top wall opening in the same direction as said concave recess.
9 . The pipe coupling of claim 8 wherein said bias member comprises a coil spring having one end engaging said cup member.
10 . The pipe coupling of claim 9 wherein said coil spring includes an opposing free end, said coil spring travelling with said shutoff valve as said shutoff valve moves toward said valve seat.
11 . A pipe coupling having automatic shutoff, comprising: an extension including an extension body with opposed first and second ends, and a flow passageway defined between the first and second ends of said extension body; a valve including a valve body with opposed first and second ends, a valve seat associated with said valve body, and a flow passageway defined between the first and second ends of said valve body; a shutoff valve movably mounted to said valve body for movement toward and away from said valve seat; a bias member between said valve body and said shutoff valve, urging said shutoff valve toward said valve seat; a holding member having opposed first and second ends, extending between said extension body and said shutoff valve, holding said shutoff valve in an open position away from said valve seat; joining means joining said extension body to said valve body so as to bring the flow passageways of said extension body and said valve body into flow communication with one another; and one of said extension body and said valve body including a weakened portion which fails so as to separate the joinder of the valve body to at least a portion of the extension body upon application of an impact force to said pipe coupling so as to allow said holding member to move from a position between said extension body and said shutoff valve, allowing said shutoff valve to move toward said valve seat for seating engagement therewith, at least substantially blocking flow through said valve body.
12 . The pipe coupling of claim 11 wherein said extension body includes a line of weakness comprising said weakened portion.
13 . The pipe coupling of claim 12 wherein said line of weakness is located adjacent the second end of said extension body.
14 . The pipe coupling of claim 11 wherein said extension body is divided by a line of weakness, comprising a weakened portion, into a first weakened portion and second portion.
15 . The pipe coupling of claim 11 wherein the extension body is divided by a line of weakness, comprising said weakened portion, into first and second axially adjacent weakened portions with the second portion joined to said valve body.
16 . The pipe coupling of claim 11 wherein said shutoff valve includes a top wall with opposed first and second surfaces surrounded by an outer side wall, the side wall and the first surface cooperating to define a seating surface of the shutoff valve and said first surface and said side wall cooperate to define a concave recess.
17 . The pipe coupling of claim 16 wherein, with movement of said shutoff valve toward said valve seat, said concave recess faces the direction of flow through said pipe coupling, so that a flow force urges said shutoff valve into contact with said valve seat.
18 . The pipe coupling of claim 16 further comprising a cup member on said top wall opening in the same direction as said concave recess.
19 . The pipe coupling of claim 18 wherein said bias member comprises a coil spring having one end engaging said cup member.
20 . The pipe coupling of claim 19 wherein said coil spring includes an opposing free end, said coil spring traveling with said shutoff valve as said shutoff valve moves toward said valve seat.