Slingline arrangement for oil well masts

Claim 1

IN AN OIL OIL WELL DRILLING STRUCTURE, THE COMBINATION WITH A BASE, DRAWWORKS MOUNTED THEREON, A GIN POLE MOUNTED ON SAID BASE, A RECLINING MAST HINGED TO THE BASE IN FRONT OF THE GIN POLE AND EXTENDING FORWARD AWAY FROM IT, A LINE EXTENDING FROM THE DRAWWORKS UP OVER THE GIN POLE AND FORWARD TO THE FRONT END OF THE MAST AND THEN BACK INSIDE THE MAST, A TRAVELLING BLOCK CONNECTED WITH THE LINE INSIDE THE MAST NEAR THE GIN POLE, AND A PAIR OF LATERALLY SPACED SUBSTANTIALLY VERTICAL SHEAVES MOUNTED AT THE TOP OF THE GIN POLE; OF A PAIR OF LATERALLY SPACED SUBSTANTIALLY VERTICAL SHEAVES MOUNTED AT THE BOTTOM OF THE GIN POLE BELOW SAID TOP SHEAVES, A PAIR OF LATERALLY SPACED SHEAVES CONNECTED TO THE UPPER PART OF THE RECLINING MAST, AND A SLINGLINE HAVING ENDS SECURED TO THE UPPER PART OF THE GIN POLE, THE SLINGLINE BEING DOUBLED ON ITSELF AND EXTENDING FROM THE GIN POLE FORWARD AND AROUND SAID MAST SHEAVES AND THEN BACK OVER THE TOP GIN POLE SHEAVES AND DOWN UNDER THE BOTTOM GIN POLE SHEAVES AND FORWARD INTO THE MAST TO FORM A LOOP THEREIN FOR CONNECTION TO THE TRAVELING BLOCK, WHEREBY WHEN SAID DRAWWORKS IS OPERATED TO PULL THE TRAVELLING BLOCK FORWARD IN THE RECLINING MAST THE SLINGLINE WILL PULL ON SAID MAST SHEAVES AND THEREBY HELP TO SWING THE MAST UPWARD AND BACKWARD TOWARD THE GIN POLE TO UPRIGHT POSITION.