Hydraulic coupling device

A coupling arrangement comprising a coupling device and a connector, the coupling device being constituted by a cylindrical casing, a plurality of plug pins housed within the casing, and a holder within said casing for holding the plug pins, and means for retaining said holder within said casing, and the connector being provided with a plurality of sockets which, in use, receive and mate with the plug pins of the coupling device, the plug pins each being connectible to a respective one of a plurality of high-pressure hydraulic conduits which are bunched together to form a multi-core duct, the connector being constituted by two detachably interconnected parts which meet in a plane that lies transversely to the axial direction of the sockets and that passes through the sockets axially spaced from the open ends of said sockets, resilient sealing rings located at said plane to constitute a seal between each respective plug pin and socket when the coupling arrangement is mated, and means for rigidly fastening said two detachably interconnected parts of said connector together which applies compression force to said sealing rings when said two parts are assembled, wherein said plug pins enter said sockets and pass through the compressed sealing rings when said coupling device and connector are mated to form said coupling arrangement without requiring application of axial force between said coupling device and connector to compress said sealing rings, and means to retain said coupling device and connector in mating engagement.