Patent ID: 7306007
Filing Date: 2007-12-11
Classification: F16L,Y10T

Abstract:
1. A pipe coupling comprising: a socket and a plug that have an appropriate lock mechanism and are detachably connected to each other; said socket having a socket fluid passage that is opened or closed with a ball valve incorporated therein, said socket fluid passage having a primary fluid passage portion through which a fluid is supplied into said socket, said primary fluid passage portion being provided therein with a cylindrical seal member in pressure contact with said ball valve to seal between said ball valve and an inner wall of said socket fluid passage, and said ball valve being rotatable to open when said socket and said plug are locked to each other by said lock mechanism; wherein said ball valve is provided with a sub-valve bore that allows the fluid in the primary fluid passage portion of said socket fluid passage to be delivered to a secondary fluid passage portion of said socket fluid passage through said ball valve before a valve bore of said ball valve opens into said socket fluid passage when said ball valve is rotated; wherein the secondary fluid passage portion of said socket fluid passage is provided with a movable valve that retracts to open said secondary fluid passage portion when it is pushed by a distal end of said plug as inserted into said socket, and when said plug is removed from said socket, said movable valve advances to close said secondary fluid passage portion; said ball valve having a ball rotating shaft to rotate it, said ball rotating shaft being formed with a purge passage having a purge inlet that opens into a secondary space formed in said secondary fluid passage portion between said ball valve and said movable valve, said purge passage further having a purge outlet that opens outside said socket fluid passage, said purge outlet being capable of assuming either of two positions, including one where said purge outlet communicates with a fluid recovery passage provided in said socket, and another where it does not, according to a difference in rotation angle of said ball rotating shaft, wherein when the rotation angle of said ball rotating shaft coincides with an angle at which the valve bore of said ball valve is open into said socket fluid passage, the purge outlet is not in communication with the fluid recovery passage, whereas when the rotation angle of said ball rotating shaft is such that the valve bore of the ball valve is not open into said socket fluid passage, the purge outlet is in communication with the fluid recovery passage.