Sprocket and chain drive

Claim 1

IN A CRAWLER TRACTOR HAVING A POWER OUTPUT AXLE AND A APIR OF ENDLESS TRACKS POSITIONED ON OPPOSITE SIDES OF SAID CRAWLER TRACTOR AND DRIVEN BY SAID OUTPUT AXLE, EACH OF SAID TRACKS HAVING A SEPARATE ENDLESS CHAIN PORTION COMPRISING A PLURALITY OF LINKS HAVING SPACED SIDE MEMBERS WITH TRANSVERSE, CYLINDRICAL, EQUALLY SPACED, SPROCKET ENGAGING BUSHINGS OF A SINGLE UNIFORM DIAMETER EXTENDING BETWEEN SAID SIDE MEMBERS, THE IMPROVEMENT COMPRISING A PAIR OF DRIVE SPROCKETS MOUNTED ON SAID POWER OUTPUT AXLE AND EACH ENGAGING THE CHAIN PORTION OF ONE OF SAID TRACKS, EACH OF SAID SPROCKETS HAVING FIRST AND SECOND SIDE SURFACES AND A PLURALITY OF TEETH EVENLY SPACED ALONG THGE OUTER PERIPHERY THEREOF, ADJACENT TEETH PARTIALLY DEFINING BUSHING RECEIVING RECEPTACLES, SAID RECEPTACLES BEING FURTHER DEFINED BY A PAIR OF PART-CYLINDRICAL SURFACES OF SAID UNIFORM DIAMETER EXTENDING BETWEEN SAID FIRST AND SECOND SIDE SURFACES OF SAID SPROCKET, SAID PART-CYLINDRICAL SURFACES HAVING SEPARATE SPACED PARALLEL AXES, SAID AXES BEING SPACED ON OPPOSITE SIDES FROM A PLANE EXTENDING RADIALLY OUTWARDLY FROM THE CENTER OF ROTATION OF SAID BISECTING SAID RECEPTACLE, SAID AXES FURTHER BEING SITUATED SUBSTANTIALLY PARALLEL TO THE CENTER OF ROTATION OF SAID SPROCKET, A PLANE ROOT SURFACE TANGENT TO EACH OF SAID PARTCYLINDRICAL SURFACES AND SITUATED SUBSTANTIALLY NORMAL TO SAID RADIAL PLANE, AND A PAIR OF OUT ER PLANE FACES, EACH TANGENT TO ONE OF SAID PART-CYLINDRICAL SURFACES EXTENDING OUTWARDLY AT AN ANGLE OF NOT MORE THAN 22 DEGREES WITH RESPECT TO SAID RADIAL PLANE, THE EFFECTIVE PITCH OF SAID SPROCKET BEING LESS THAN THE PITCH OF ITS MATING CHAIN.