Suction nozzle

Claim 1

IN COMBINATION, A NOZZLE COMPRISING A HOLLOW BODY INCLUDING FRONT AND REAR SPACED WALLS HAVING BOTTOM LIP PORTIONS DEFINING A SUCTION INLET NORMALLY MOVABLE FORWARD AND BACKWARD ON THE SURFACE, THE NOZZLE BODY HAVING AN OUTLET AND FURTHER INCLUDING WALL MEANS DEFINING A CHAMBER OF CYLINDRICAL FORM WHOSE AXIS IS SUBSTANTIALLY PARALLEL TO THE DIRECTION THE NOZZLE IS NORMALLY MOVED FORWARD AND BACKWARD ON THE SURFACE, THE CHAMBER BEING REMOVED FROM THE INLET AND FORMING A PART OF THE PATH OF FLOW FOR AIR FROM THE INLET TO THE OUTLET, THE EFFECTIVE SIZE OF THE INLET BEING THE SAME WHEN THE NOZZLE IS MOVED FORWARD AND REARWARD IN THE NORMAL DIRECTION WITH ITS SUCTION INLET IN CONTACT WITH THE SURFACE, THE CHAMBER WALL MEANS BEING APERTURED TO PROVIDE AN OPENING THEREIN, A SLEEVE VALVE MEMBER COMPRISING A HOLLOW CYLINDRICAL ELEMENT WHICH IS AXIALLY MOVABLE IN THE CHAMBER AT THE IMMEDIATE VICINITY OF ITS WALL MEANS, THE HOLLOW ELEMENT BEING APERTURED TO ESTABLISH COMMUNICATION BETWEEN THE INLET AND THE INTERIOR OF THE CHAMBER AND TO PROVIDE A PATH OF FLOW INTO THE INTERIOR OF THE CHAMBER FOR AIR PASSING THROUGH THE OPENING IN THE CHAMBER WALL MEANS, STRUCTURE INCLUDING SAID VALVE MEMBER FOR DECREASING THE SIZE OF THE OPENING DURING FORWARD MOVEMENT OF THE NOZZLE RESPONSIVE TO FORWARD THRUST APPLIED THERETO WHILE ITS INLET IS IN CONTACT WITH THE SURFACE AND FOR INCREASING THE SIZE OF THE OPENING DURING REARWARD MOVEMENT OF THE NOZZLE RESPONSIVE TO A PULLING FORCE THEREON WHILE ITS INLET IS IN CONTACT WITH THE SURFACE, AND FIRST AND SECOND RESILIENT MEANS DISPOSED IN THE CHAMBER, SAID FIRST AND SECOND RESILIENT MEANS BEING SO FORMED AND ARRANGED THAT SAID FIRST RESILIENT MEANS IS COMPRESSED RESPONSIVE TO MOVEMENT OF THE HOLLOW ELEMENT IN ONE DIRECTION DURING FORWARD MOVEMENT OF THE NOZZLE AND SAID SECOND RESILIENT MEANS IS COMPRESSED RESPONSIVE TO MOVEMENT OF THE HOLLOW ELEMENT IN THE OPPOSITE DIRECTION DURING REARWARD MOVEMENT OF THE NOZZLE.