Material-handling vehicle

Claim 1

IN COMBINATION WITH THE FRAME OF AN AUTOMOTIVE VEHICLE, A MATERIAL-HANDLING HEAD, A FOLDING BOOM STRUCTURE EXTENDING BETWEEN THE VEHICLE FRAME AND THE HEAD COMPRISED OF HEEL AND REACH SECTIONS CONNECTED BY AN INTERVENING ELBOW JOINT, BOTH OF SAID SECTIONS COMPRISING A SET OF PARALLEL-MOTION LINKS, THE LINKS OF THE HEEL SECTION EXTENDING UPWARDLY FROM THE FRAME TO THE ELBOW OF THE ELBOW JOINT WITH THE PARALLEL SWING MOTION BEING ABOUT LONGITUDINALLY SPACED TRANSVERSE HORIZONTAL AXES, THE LINKS OF THE REACH SECTION EXTENDING FORWARDLY FROM THE ELBOW TO THE HEAD WITH THE PARALLEL SWING MOTION BEING ABOUT VERTICALLY SPACED TRANSVERSE HORIZONTAL AXES, AT LEAST ONE LINK OF EACH OF SAID SECTIONS HAVING A WIDE BEARING AT EACH OF ITS TWO PIVOTED ENDS, AND INDEPENDENT POWER-OPERATED MEANS ONE FOR SWINGING THE HEEL SECTION OF SAID BOOM RELATIVE TO THE FRAME AND ONE FOR SWINGING THE REACH SECTION RELATIVE TO THE HEEL SECTION, THE MEANS FOR SWINGING THE REACH SECTION RELATIVE TO THE HEEL SECTION COMPRISING A HYDRAULIC JACK HAVING ONE END CONNECTED TO THE FRAME AND THE OTHER END CONNECTED TO ONE OF THE LINKS OF THE REACH SECTION AT A POINT THEREON DISTAL TO THE AXIS ABOUT WHICH THE LATTER SWINGS, THE POWER-OPERATED MEANS FOR SWINGING THE HEEL SECTION ALSO COMPRISING A HYDRAULIC JACK, SAID LATTER JACK BEING PIVOTED AT ONE END TO THE FRAME AT A POINT THEREON SPACED A SUBSTANTIAL DISTANCE TO THE FRONT OF THE BOOM''S FRAME PIVOTS AND AT THE OTHER END TO THE BOOM STRUCTURE AT A POINT THEREON PROXIMAL TO THE ELBOW.