Coupling for transferring fluids, method for closing the fluid duct of such a coupling, and preferred use of this coupling

A coupling for transferring fluids, having a housing and a nipple which can be fixed thereon, which can be separated from the housing when a predetermined axial tensile force is exceeded while overcoming a spring force, and having a fluid channel which passes through the housing and the nipple, in the course of which a housing-side and a nipple-side non-return valve are arranged, and which is guided in a radially directed manner around a vented cylindrical interior of the nipple, and in which a closure mechanism comprises a housing-side pin and a nipple-side pin and a sleeve arranged between said pins, which is arranged in an axially movable manner in the interior of the nipple, and can be locked by means of spring-pressure-mounted locking elements with the housing-side pin, such that when the nipple is fixed the non-return valves are held open against their spring force, and when the nipple is released the housing-side non-return valve is completely closed and the nipple-side non-return valve is at least partially closed, and in which the sleeve engages around a housing-side piston, and via the locking elements can be fixed thereto and can be separated therefrom against the spring force, and the housing-side pin is guided in an axially movable manner in the piston], and is supported in an open state of the housing-side non-return valve against the locking elements.