Vehicle mounted material-handling equipment

Claim 1

IN COMBINATION WITH THE FRAME OF A TRACTOR VEHICLE, A BOOM PIVOTED THERETO FOR VERTICAL SWING MOVEMENT ABOUT A TRANSVERSE HORIZONTAL AXIS WHICH LIES TO THE REAR OF A DRIVER''S STATION AT THE APPROXIMATE HEAD LEVEL OF A DRIVER OCCUPYING THE STATION, A MATERIAL-HANDLING HEAD PIVOTALLY SUPPORTED FROM THE OUTER END OF THE BOOM FOR VERTICAL SWING MOVEMENT ABOUT A TRANSVERSE HORIZONTAL AXIS, A GRASSHOPPER LINKAGE PIVOTALLY ATTACHED BY ITS TWO ENDS ONE END TO THE BOOM AND THE OTHER END TO THE HEAD AT POINTS THEREON PROXIMAL TO BUT OFFSET FROM THE PIVOTAL AXIS OF THE HEAD, AND INDEPENDENT DOUBLE-ACTING HYDRAULIC JACKS FOR OPERATING SAID BOOM AND FOR OPERATING THE HEAD ONE JACK EXTENDING BETWEEN THE VEHICLE AND THE BOOM AND THE OUTER JACK EXTENDING BETWEEN THE BOOM AND THE ELBOW JOINT WHICH CONNECTS THE TWO LINKS OF THE GRASSHOPPER LINKAGE, THE BOOM COMPRISING COMPANION MATCHING ARMS ONE LYING AT ONE SIDE AND THE OTHER AT THE OTHER SIDE OF THE VEHICLE, SAID ARMS, WHEN THE BOOM OCCUPIES A LOWERED POSITION, EXTENDING FORWARDLY FROM THE PIVOT AXIS IN A GENERALLY HORIZONTAL PLANE ELEVATED ABOVE THE DRIVER''S STATION AND THENCE REACHING DOWNWARDLY ON A STEEP INCLINATIN TO CONTACT THE GROUND AT A POINT CLOSELY ADJACENT TO A PERPENDICULAR DROPPED FROM THE FORWARD EXTREMITY OF THE FRAME, SAID BOOM HAVING ITS TWO SIDE ARMS JOINED BY CROSS-MEMBERS LOCATED AT EACH OF THE TWO ENDS OF SAID HORIZONTAL PORTION OF THE BOOM ARMS AND HAVING A CANOPY EXTENDING BETWEEN SAID CROSS-MEMBERS IN SPANNING RELATION TO THE SIDE ARMS.