Underwater mechanical brush

Claim 1

A UNITARY BRUSHING DEVICE FOR UNDERWATER CLEANING OF THE SURFACE OF AN IMMERSED STRUCTURE, COMPRSING A BRUSH ELEMENT AND A SHAFT ON WHICH SAID ELEMENT IS MOUNTED, A HYDRAULIC MOTOR FOR ROTATING THE SHAFT, MEANS FOR SUPPLYING THE MOTOR WITH A PRESSURE LIQUID, MEANS FOR WITHDRAWING SUCH LIQUID AFTER ITS PASSAGE THROUGH THE DEVICE, MEANS FOR CONTROLLING THE LIQUID DISTRIBUTION CONDITIONS IN THE DEVICE TO CONTROL THE SPEED OF ROTATION OF THE BRUSH ELEMENT, THE LAST-MENTIONED MEANS COMPRISING A VALVE COOPERATING WITH THE SUPPLY MEANS AND THE DISCHARGE MEANS TO RECEIVE THE SUPPLIED LIQUID AND DIRECT THE SAME TOWARDS THE DISCHARGE, THE MOVING PART OF THE VALVE BEING OPERABLE TO A MOTOR STOP POSITION WITHOUT THE FLOW OF LIQUID BETWEEN THE SUPPLY AND THE DISCHARGE BEING INTERRUPTED, SAID VALVE BEING OF THE KIND COMPRISING A PLUG ROTATING IN A BORE IN A CASING, AT LEAST ONE SUPPLY LINE FOR THE DRIVING LIQUID TO THE DEVICE TERMINATING IN AN ORIFICE IN THE SAID BORE, AT LEAST ONE DISCHARGE LINE FOR THE DRIVING LIQUID LEAVING THE DEVICE COMMUNICATING WITH AT LEAST ONE PORT IN THE BORE PERIPHERY, SAID PLUG HAVING, AT