Inertial mass, force multiplying device

Claim 2

A BULLDOZER PUSHER BALDE FORCE AUGMENTING MEANS COMPRISING AN INERTIAL MASS SUSPENDED BY MEANS OF PIVOTED LINKS TO SWING IN THE DIRECTION OF OPERATIVE MOVEMENT OF SAID PUSHER BLADE, A HYDRAULIC CYLINDER MOUNTED ON SAID PUSHER BLADE IN ALIGNMENT WITH THE PATH OF MOVEMENT OF SAID INERTIAL MASS, A PISTON CLOSELY FITTED WITHIN SAID CYLINDER, SAID PISTON HAVING A PISTON ROD EXTENDING OUTWARDLY FROM ONE END OF SAID CYLINDER AND ATTACHED TO MOVE WITH SAID INERTIAL MASS, THE TRANSVERSE PISTON AREA ON THE SIDE OF SAID PISTON ROD BEING LESS THAN THE TRANSVERSE PISTON AREA OPPOSITE SAID PISTON ROD, A HIGH PRESSURE HYDRAULIC SOURCE, A HYDRAULIC CONTROL VALVE HAVING AN ELEMENT MOVABLE BETWEEN EXTENDED AND RETRACTED POSITIONS AND HAVING HYDRAYLIC PASSAGES THEREIN WHICH CONNECT SAID HIGH PRESSURE HYDRAULIC SOURCE WITH BOTH ENDS OF SAID HYDRAULIC CYLINDER IN THE EXTENDED POSITION OF SAID ELEMENT AND WHICH IN THE RETRACTED POSITION CONNECTS ONE END OF SAID CYLINDER TO A LOW PRESSURE HYDRAULIC DRAIN WHILE THE OTHER END REMAINS CONNECTED TO SAID HIGH PRESSURE HYDRAULIC SOURCE, SAID CONTROL VALVE BEING CAPABLE OF HYDRAULICALLY SEALING SAID ONE END OF SAID CYLINDER INTERMEDIATE THE EXTENDED AND RETRACTED POSITIONS OF SAID ELEMENTS ACTUATING MEANS FOR ALTERNATELY MAINTAINING SAID ELEMENT IN ITS EXTENDED AND RETRACTED POSITIONS AND FOR CHANGING THE POSITION OF SAID ELEMENT WHENEVER THE POSITION AND VELOCITY OF SAID PISTON ATTAIN PREDETERMINED LIMITS, MEANS FOR MOUNTING SAID PUSHER BLADE TO SWING IN THE LONGITUDINAL DIRECTION OF A BULLDOZER BETWEEN FIXED LIMITS, AND HYDRAULIC PISTON AND CYLINDER MEANS OPERATIVE TO URGE SAID PUSHER BLADE FORWARDLY OF SAID BULLDOZER AGAINST ONE FIXED LIMIT CONTINUOUSLY WITH A FORCE SOMEWHAT LESS THAN THE FRICTIONAL GRIPPING FORCE OF THE TRACKS OF SAID BULLDOZER.