Patent ID: 7857356

Claim:
A coupling comprising a first part and a second part connectable to each other in a male-female mating arrangement; said first part having a housing with a bore and a slide element, said slide element being arranged movable within said bore by connection and disconnection of said second part; a first transfer path in said housing having an open end in said bore and being in contact with a second transfer path in said second part when said second part is connected with said first part but otherwise closed by said slide element, said slide element being moveable from a closed to an open position by interaction with said second part; said slide element having a first and second end surface, said first end surface in abutment against said second part in a connected state of said coupling, said second end surface in a disconnected state of said coupling being exposed to a surrounding fluid around said coupling, a sum total of areas exposed to the surrounding fluid on said first end surface is at least equal to a sum total of areas exposed to the surrounding fluid on said second end surface; and at least one of said slide element and a surface of said bore having a circumferential groove communicating with said first transfer path in the disconnected state of said coupling; wherein said slide element having a one way valve arrangement connecting said first transfer path with the surrounding fluid in the disconnected state of said coupling, said valve arrangement allowing fluid to pass from said first transfer path to the surrounding fluid.