Power couplings

Claim 1

IN AN AUTOMATIC POWER COUPLING FOR A TRACTOR HAVING HITCHING MEANS, A LINKAGE MOVABLE IN A GENERALLY UP AND DOWN DIRECTION BY OPERATION OF POWER MEANS ON THE TRACTOR AND A POWER TAKE-OFF SHAFT, AND AN IMPLEMENT HAVING HITCHING MEANS FOR CO-OPERATION WITH THE TRACTOR HITCHING MEANS AND A POWER DRIVE SHAFT, THE COMBINATION OF A FIRST SHAFT ASSEMBLY ADAPTED TO BE CONNECTED TO SAID POWER TAKE-OFF SHAFT THROUGH A FIRST UNIVERSAL JOINT, A SECOND SHAFT ASSEMBLY FOR SLIDABLE COUPLING ENGAGEMENT WITH SAID FIRST SHAFT ASSEMBLY AND ADAPTED TO BE CONNECTED TO SAID POWER DRIVE SHAFT THROUGH A SECOND UNIVERSAL JOINT, A SUSPENSION DEVICE COMPRISING FRAME MEANS MOUNTED ON SAID TRACTOR LINKAGE AND MOVABLE WITH SAID LINKAGE ON OPERATION OF SAID POWER MEANS, AND RESILIENT MEANS SUSPENDING SAID FIRST SHAFT ASSEMBLY FROM SAID FRAME BEING SO CONSTRUCTED AND ARRANGED THAT SAID FIRST SHAFT ASSEMBLY IS MOVABLE IN A GENERALLY UP AND DOWN DIRECTION WITH SAID FRAME MEANS TO BRING IT INTO SUBSTANTIAL ALIGNMENT WITH SAID SECOND SHAFT ASSEMBLY PRIOR TO ENGAGEMENT OF SAID SHAFT ASSEMBLIES AND THAT SAID FIRST SHAFT ASSEMBLY IS PERMITTED A FREE AND UNRESTRICTED MOVEMENT WITH SAID SECOND SHAFT ASSEMBLY WHEN SAID SHAFT ASSEMBLIES ARE IN ENGAGEMENT, AND MEANS FOR MAINTAINING SAID SECOND SHAFT ASSEMBLY IN SUBSTANTIAL ALIGNMENT WITH SAID POWER DRIVE SHAFT PRIOR TO ENGAGEMENT OF SAID SHAFT ASSEMBLIES.