Hydraulic self-leveling device for a front mounted bucket type material loader

Claim 1

A DEVICE FOR AUTOMATICALLY CONTROLLING THE LEVEL OF THE WORK BUCKET OF A MATERIAL LOADER HAVING (A) A WORK BUCKET SUPPORTED FORWARDLY OF THE LOADER BY A BOOM STRUCTURE MOUNTED ON THE FRAME THEREOF FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS EXTENDING TRANSVERSELY OF SAID BOOM STRUCTURE ADJACENT ONE END THEREOF, SAID BOOM STRUCTURE BEING MOUNTED ADJACENT ITS OPPOSITE END FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS ON THE FRAME OF SAID LOADER, AND (B) HYDRAULIC POWER OPERATED MECHANISM OPERATIVELY ASSOCIATED WITH A SOURCE OF HYDRAULIC POWER ON SAID LOADER, SAID MECHANISM COMPRISING A FIRST HYDRAULIC CYLINDER FOR ACTUATING SAID BOTTOM STRUCTURE TO RAISE AND LOWER SAID BUCKET UNDER CONTROL OF A BOOM VALVE, AND A SECOND HYDRAULIC CYLINDER FOR ACTUATING SAID BUCKET UNDER CONTROL OF A BUCKET VALVE, SAID FIRST CYLINDER BEING MOUNTED ADJACENT ITS PISTON ROD END FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS ON SAID LOADER FRAME AND HAVING ITS HEAD END PIVOTALLY CONNECTED ADJACENT ITS OUTER EXTREMITY TO SAID BOOM STRUCTURE IN PREDETERMINED SPACED RELATION WITH SAID HORIZONTAL AXES OF SAID BOOM STRUCTURE AND SAID BUCKET, SAID SECOND CYLINDER BEING MOUNTED ADJACENT IS HEAD END FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS ON SAID BOOM STRUCTURE AND HAVING ITS PISTON ROD PIVOTALLY CONNECTED ADJACENT INTS OUTER EXTREMITY TO SAID BUCKET IN PREDETERMINED SPACED RELATION WITH SAID BOOM STRUCTURE, SAID DEVICE COMPRISING AUXILIARY HYDRAULICALLY RATED MECHANISM OPERATIVELY ASSOCIATED WITH SAID SOURCE INCLUDING (C) A SINGLE-ACTING THIRD HYDRAULIC CYLINDER (D) A FIRST RELIEF, ANTI-CAVITATION VALVE, AND (E) A SECOND RELIEF, DIVERTER VALVE SAID THIRD CYLINDER BEING OF THE SLAVE TYPE, SAID THIRD CYLINDER AND SAID RELIEF VALVES BEING IN OPERATIVE HYDRAULIC COMMUNICATION WITH ONE ANOTHER AND WITH SAID SECOND CYLINDER AND ARRANGED TO OPERATE WHEREBY UPON OPERATION OF SAID FIRST CYLINDER TO RAISE SAID BOOM STRUCTURE AND SAID BUCKET, SAID THIRD CYLINDER AND SAID FIRST RELIEF VALVE ARE OPERATED TO APPLY FLUID UNDER PRESSURE TO SAID SECOND CYLINDER OPPOSING RETRACTION OF THE PISTON ROD THEREOF THEREBY TO PREVENT PIVOTING OF THE BUCKET ABOUT THE SAID HORIZONTAL AXIS THEREOF, SAID THIRD CYLINDER AND SAID RELIEF VALVES BEING FURTHER ARRANGED TO OPERATE WHEREBY UPON OPERATION OF SAID FIRST CYLINDER TO LOWER SAID BOOM STRUCTURE AND SAID BUCKET, SAID THIRD CYLINDER AND SAID SECOND RELIEF VALVE ARE OPERATED TO APPLY FLUID UNDER PRESSURE TO SAID SECOND CYLINDER ENABLING RETRACTION OF THE PISTON ROD THEREOF THEREBY TO PREVENT PIVOTING OF THE BUCKET ABOUT THE SAID HORIZONTAL AXIS THEREOF.

Claim 2

A DEVICE FOR AUTOMATICALLY CONTROLLING THE LEVEL OF THE WORK BUCKET OF A MATERIAL LOADER HAVING (A) A WORK BUCKET SUPPORTED FORWARDLY OF THE LOADER BY A BOOM STRUCTURE MOUNTED ON THE FRAME THEREOF FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS EXTENDING TRANSVERSELY OF SAID BOOM STRUCTURE ADJACENT ONE END THEREOF, SAID BOOM STRUCTURE BEING MOUNTED ADJACENT ITS OPPOSITE END FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS ON THE FRAME OF SAID LOADER, AND (B) HYDRAULIC POWER OPERATED MECHANISM OPERATIVELY ASSOCIATED WITH A SOURCE OF HYDRAULIC POWER ON SAID LOADER, SAID MECHANISM COMPRISING A FIRST HYDRAULIC CYLINDER FOR ACTUATING SAID BOTTOM STRUCTURE TO RAISE AND LOWER SAID BUCKET UNDER CONTROL OF A BOOM VALVE, AND A SECOND HYDRAULIC CYLINDER FOR ACTUATING SAID BUCKET UNDER CONTROL OF A BUCKET VALVE, SAID FIRST CYLINDER BEING MOUNTED ADJACENT ITS PISTON ROD END FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS ON SAID LOADER FRAME AND HAVING ITS HEAD END PIVOTALLY CONNECTED ADJACENT ITS OUTER EXTREMITY TO SAID BOOM STRUCTURE IN PREDETERMINED SPACED RELATION WITH SAID HORIZONTAL AXES OF SAID BOOM STRUCTURE AND SAID BUCKET, SAID SECOND CYLINDER BEING MOUNTED ADJACENT IS HEAD END FOR PIVOTAL MOVEMENT ABOUT A GENERALLY HORIZONTAL AXIS ON SAID BOOM STRUCTURE AND HAVING ITS PISTON ROD PIVOTALLY CONNECTED ADJACENT INTS OUTER EXTREMITY TO SAID BUCKET IN PREDETERMINED SPACED RELATION WITH SAID BOOM STRUCTURE, SAID DEVICE COMPRISING AUXILIARY HYDRAULICALLY RATED MECHANISM OPERATIVELY ASSOCIATED WITH SAID SOURCE INCLUDING (C) A SINGLE-ACTING THIRD HYDRAULIC CYLINDER (D) A FIRST RELIEF, ANTI-CAVITATION VALVE, AND (E) A SECOND RELIEF, DIVERTER VALVE SAID THIRD CYLINDER BEING OF THE SLAVE TYPE, SAID THIRD CYLINDER AND SAID RELIEF VALVES BEING IN OPERATIVE HYDRAULIC COMMUNICATION WITH ONE ANOTHER AND WITH SAID SECOND CYLINDER AND ARRANGED TO OPERATE WHEREBY UPON OPERATION OF SAID FIRST CYLINDER TO RAISE SAID BOOM STRUCTURE AND SAID BUCKET, SAID THIRD CYLINDER AND SAID FIRST RELIEF VALVE ARE OPERATED TO APPLY FLUID UNDER PRESSURE TO SAID SECOND CYLINDER OPPOSING RETRACTION OF THE PISTON ROD THEREOF THEREBY TO PREVENT PIVOTING OF THE BUCKET ABOUT THE SAID HORIZONTAL AXIS THEREOF, SAID THIRD CYLINDER AND SAID RELIEF VALVES BEING FURTHER ARRANGED TO OPERATE WHEREBY UPON OPERATION OF SAID FIRST CYLINDER TO LOWER SAID BOOM STRUCTURE AND SAID BUCKET, SAID THIRD CYLINDER AND SAID SECOND RELIEF VALVE ARE OPERATED TO APPLY FLUID UNDER PRESSURE TO SAID SECOND CYLINDER ENABLING RETRACTION OF THE PISTON ROD THEREOF THEREBY TO PREVENT PIVOTING OF THE BUCKET ABOUT THE SAID HORIZONTAL AXIS THEREOF.