Device for drilling wells

Claim 1

A DEVICE FOR DRILLING A WELL WHICH COMPRISES, IN COMBINATION, A HOLLOW DRILL STEM CONNECTED AT ITS LOWER END TO A DRILL BIT, A DRILL COLLAR ARRANGED WITHIN SAID DRILL STEM PROVIDED WITH A PASSAGEWAY FOR DRILLING FLUID, A STATIONARY VALVE HOUSING ARRANGED IN THE PASSAGEWAY IN SAID DRILL COLLAR HAVING PORTS FOR PASSAGE OF DRILLING FLUID THERETHROUGH, A ROTATABLE VALVE ELEMENT ARRANGED IN SAID VALVE HOUSING, SAID ROTATABLE VALVE ELEMENT BEING PROVIDED WITH PORTS INCLINED TO THE AXIS OF THE DRILL COLLAR FOR PASSAGE OF DRILLING FLUID AND OPPOSED SURFACES ALSO INCLINED TO THE AXIS OF THE DRILL COLLAR, SAID VALVE ELEMENT BEING OF A GENERAL CYLINDRICAL SHAPE HAVING OPPOSITE PERIPHERAL SEGMENTAL RECESSES PROVIDING SAID OPPOSED INCLINED SURFACES, FLOW OF DRILLING FLUID THROUGH THE DRILL COLLAR PASSAGEWAY IMPINGING AGAINST SAID INCLINED SURFACES TO ROTATE SAID VALVE ELEMENT RELATIVE TO THE PORTS OF SAID VALVE HOUSING TO RESTRICT SAID FLOW OF DRILLING FLUID TO FLOW THROUGH SAID PORTS IN THE ROTATABLE VALVE ELEMENT WHEN SAID ROTATABLE VALVE ELEMENT IS ROTATED INTO POSITION TO CLOSE THE PORTS IN THE VALVE HOUSING, A KEYWAY ARRANGED IN SAID DRILL STEM, AND A KEY ON SAID DRILL COLLAR SLIDABLY ARRANGED IN SAID KEYWAY TO PREVENT UPWARD TRAVEL OF VIBRATIONS CREATED BY RESTRICTION OF FLOW OF SAID DRILLING FLUID WHEREBY ROTATION OF SAID ROTATABLE VALVE ELEMENT IS MAINTAINED AND SAID VIBRATIONS ARE TRANSMITTED DOWNWARDLY ON SAID DRILL STEM ON RESTRICTION OF FLUID FLOW THROUGH THE PASSAGEWAY IN SAID DRILL COLLAR TO FLOW THROUGH SAID PORTS IN THE ROTATABLE VALVE ELEMENT.