Rear-mounted ripper

Claim 1

IN GROUND-WORKING EQUIPMENT, (A) A TRACTOR, (I) ALIGNED FRONT AND REAR SPROCKETS ON EACH SIDE OF SAID TRACTOR ADAPTED TO ENGAGE CONTINUOUS TRACKS TO PROPEL THE TRACTOR OVER THE GROUND, (II) SAID TRACTOR HAVING A CENTER OF GRAVITY BETWEEN SAID FRONT AND REAR SPROCKETS AND ADJACENT SAID REAR SPROCKETS, (B) A FORWARDLY-EXTENDING FRAME ON SAID TRACTOR, SAID FRAME INCLUDING (I) A PAIR OF PUSH ARMS EACH PIVOTALLY MOUNTED ON SAID TRACTOR AT THE REAR END THEREOF, (II) A DOZER BLADE PIVOTALLY MOUNTED ON SAID ARMS AT THE FORWARD ENDS THEREOF FOR DOZING ACTION UPON FORWARD TRACTOR MOVEMENT, (III) A BRACE BAR PIVOTALLY AND DIAGONALLY INTERCONNECTED BETWEEN SAID ARMS AND SAID DOZER BLADE, (IV) A CYLINDER AND PISTON ROD UNIT PIVOTALLY INTERCONNECTED BETWEEN SAID DOZER BLADE AND TRACTOR TO VARY THE INCLINATION OF SAID BLADE, AND (C) A REARWARDLY-EXTENDING BRACKET ON SAID TRACTOR, SAID BRACKET INCLUDING (I) AN ELONGATED BEAM CONNECTED TO SAID TRACTOR REARWARDLY OF SAID REAR SPROCKETS AND EXTENDING TRANSVERSELY OF SAID TRACTOR, (II) A PAIR OF BRACKET PUSH ARMS EACH PIVOTALLY MOUNTED ON SAID BEAM AT THE FORWARD ARM END, (III) A CROSS BAR EXTENDING BETWEEN SAID BRACKET ARMS AT THE REARWARD ARM ENDS, (IV) A PLURALITY OF RIPPER TEETH MOUNTED IN SAID CROSS BAR FOR RIPPER ACTION UPON REARWARD TRACTOR MOVEMENT, AND (V) A CYLINDER AND PISTON ROD UNIT PIVOTALLY INTERCONNECTED BETWEEN SAID CROSS BAR AND SAID BRACKET TO VARY THE DEGREE OF GROUND PENETRATION OF SAID RIPPER TEETH.