Attachment for material moving vehicles such as graders and the like

Claim 1

IN COMBINATION WITH A MOBILE GRADING MACHINE OF THE TYPE HAVING AN ANNULAR REVOLVABLE BLADE MOUNTING STRUCTURE, AND A BLADE MOUNTED ON SAID ANNULAR MOUNTING STRUCTURE FOR MOVEMENT THEREWITH, AN ATTACHMENT DEVICE INCLUDING A GENERALLY RECTANGULAR GATE STRUCTURE HAVING A SUBSTANTIALLY STRAIGHT LOWER EDGE, AN ELONGATE LINK STRUCTURE HAVING ONE END CONNECTED TO SAID GATE STRUCTURE AND HAVING THE OTHER END THEREOF PIVOTALLY CONNECTED TO SAID ANNULAR BLADE MOUNTING STRUCTURE FOR VERTICAL SWINGING MOVEMENT RELATIVE THERETO BETWEEN AN ELEVATED INOPERATIVE POSITION ABOVE THE BLADE AND A LOWERED OPERATIVE POSITION WHEREIN THE LOWER PERIPHERAL EDGE OF THE GATE STRUCTURE IS DISPOSED IN ENGAGING RELATION WITH THE SURFACE OF THE GROUND, SAID GATE AND LINK STRUCTURES BEING BODILY MOVABLE WITH THE ANNULAR BLADE MOUNTING STRUCTURE DURING REVOLVING MOVEMENT OF THE LATTER, SAID GATE STRUCTURE WHEN IN SAID LOWERED POSITION BEING DISPOSED IN TRANSVERSELY EXTENDING OBSTRUCTION RELATION WITH RESPECT TO THE DISCHARGE END OF THE BLADE TO THEREBY PREVENT THE DISCHARGE OF MATERIAL THEREFROM, A MAST STRUCTURE MOUNTED ON SAID ANNULAR BLADE MOUNTING STRUCTURE AND EXTENDING UPWARDLY THEREFROM ADJACENT THE AXIS OF PIVOT OF SAID LINK STRUCTURE, AND AN ACTUATOR MECHANISM EXTENDING BETWEEN AND RESPECTIVELY CONNECTED TO THE UPPER END PORTION OF SAID MAST STRUCTURE AND SAID GATE STRUCTURE AND BEING OPERABLE FOR SELECTIVELY CAUSING VERTICAL SWINGING MOVEMENT OF SAID GATE STRUCTURE BETWEEN SAID OPERATIVE AND INOPERATIVE POSITIONS INDEPENDENTLY OF ANY MOVEMENT OF THE GRADING MACHINE BLADE RELATIVE TO THE ANNULAR BLADE MOUNTING STRUCTURE.