Material handling machine

Abstract

A self-propelled, low profile material-handling vehicle mounted on a pair of front wheels and a pair of rear wheels. The vehicle supports an extendible boom rotatable around a horizontal pivot axis that is substantially located above the rear wheels. A cab for a driver is located on one side of the boom, and a load-carrying platform is located on the side of the boom opposite the cab. A well located in the vehicle body between the cab and the load-carrying platform is positioned lower than the pivot axis of the boom and is arranged to receive the boom when it is pivoted downward toward the front wheels so that a load can be maneuvered below grade level. The pivot axis is vertically located above the top of the wheels and below the top of a steering wheel located within the cab so that the driver's vision is substantially unobstructed when a load is carried by the boom close to the grade level.

What we claim is: 
     
       1. A self-propelled, low profile vehicle for enabling a driver to carry and maneuver a load over a grade surface comprising in combination: a vehicle body having a front end and a rear end;   front axle means coupled to the vehicle body and having first end portion, a second end portion, and an axis of rotation;   rear axle means coupled to the vehicle body substantially parallel to the front axle means and having a first end portion, a second end portion, and an axis of rotation, the axes of rotation of the .[.first.]. .Iadd.front .Iaddend.and .[.second.]. .Iadd.rear .Iaddend.axle means defining a first plane;   a first front wheel coupled to the first end portion of the front axle means and having an outer periphery defining a first circle having an upper point;   a second front wheel coupled to the second end portion of the front axle means and having an outer periphery defining a second circle having an upper point;   a first rear wheel coupled to the first end portion of the rear axle means and having an outer periphery defining a third circle having an upper point;   a second rear wheel coupled to the second end portion of the rear axle means and having an outer periphery defining a fourth circle having an upper point, the upper points of the first, second, third and fourth circles defining a second plane, and the points of the third and fourth circles closest to the front axle means lying in a third plane perpendicular to the second plane;   pivoting means defining a pivot axis located above the first plane and to the rear of the third plane, said pivot axis lying in a fourth plane parallel to the first plane;   a boom mounted on the pivot axis to rotate in an operating plane substantially perpendicular to the first plane, said boom extending cantilever-fashion from the pivot axis over the front axle means to a load-bearing end;   carrying means mounted on the load bearing end for carrying the load;   hydraulic means for moving the boom in the operating plane;   a source of power for moving the vehicle over the grade surface and for supplying power to the hydraulic means;   a cab for the driver positioned entirely on a first side of the operating plane;   a well in the vehicle body positioned below the boom, said well having a lower member extending below the fourth plane for receiving the boom when the boom is pivoted downward toward the front axle means, .[.whereby the load can be maneuvered below the grade surface.]. .Iadd.said pivoting means and said well cooperating to define means for enabling the load to be maneuvered below the grade surface.Iaddend.; and   a load-carrying platform positioned on the vehicle body above the first plane entirely on a second side of the operating plane opposite the first side of the operating plane, so that the well is positioned between the cab and the platform .[.and wherein the boom is extendible and retractable.]. .Iadd.said well further defining means for enabling the boom to be extensible and retractable therein.Iaddend. .   
     
     
       2. A vehicle, as claimed in claim 1, and further comprising steering means located within the cab and linked to at least two of the wheels for controlling the movement of the vehicle, said steering means having an upper point lying in a fifth plane parallel to the first plane. 
     
     
       3. A vehicle, as claimed in claim 2, wherein the pivot axis is positioned between the second plane and the fifth plane, whereby the vision of the driver is substantially unobstructed when the vehicle is used to carry the load adjacent the grade surface and the center of gravity is maintained at a low level. 
     
     
       4. A vehicle as claimed in claim 1, wherein the hydraulic means is located in part in the well, whereby the center of gravity of the vehicle is lowered. 
     
     
       5. A vehicle, as claimed in claim 1, wherein the source of power is located at least in part below the second plane, whereby the center of gravity of the vehicle is lowered. 
     
     
       6. A vehicle, as claimed in claim 5, wherein the source of power is located between the first wheel and the third wheel. 
     
     
       7. A vehicle, as claimed in claim 1, wherein the boom comprises: a fixed section;   a first movable section telescoped inside the fixed section;   a second movable section telescoped inside the first movable section;   a first pulley movable with the first movable section;   first chain means looped around the first pulley, said first chain means having a first end connected to the fixed section and a second end connected to the second movable section;   a second pulley movable with the first movable section;   second chain means looped around the second pulley, said second chain means having a first end connected to the second movable section and a second end connected to the fixed section;   hydraulic extension means having a first end connected to the fixed section and a second end connected to the first movable section for moving the first movable section outward and inward with respect to the fixed section, whereby the first pulley and first chain means simultaneously move the second movable section outward as the first movable section is moved outward and the second pulley and second chain means simultaneously move the second movable section inward as the first movable section is moved inward.  .[.8. A vehicle, as claimed in claim 1, wherein the carrying means comprises a support positioned at the load-bearing end of the boom, a fork and a drop block mounted on the support, and means for maintaining the drop block at a constant height above the grade surface as   
     
     
        the boom is extended and retracted..]. 9. A vehicle, as claimed in claim 1, wherein the steering means comprises a steering wheel positioned so that the driver normally faces toward the front end of the vehicle body, so that the line of sight between the driver and the load is substantially unobstructed irrespective of the manner in which the boom is moved in the 
     
     
        operating plane. 10. A vehicle, as claimed in claim .[.8.]. .Iadd.23 .Iaddend.wherein the carrying means further comprises means for maintaining the fork substantially parallel to the grade surface as the 
     
     
        boom is raised and lowered. 11. A vehicle, as claimed in claim .[.8.]. .Iadd.23 .Iaddend.wherein the carrying means comprises means for pivoting the fork around a substantially vertical axis so that the load can be 
     
     
        supported simultaneously on the fork and the load-carrying platform. 12. A vehicle, as claimed in claim .[.8.]. .Iadd.23 .Iaddend.wherein the fork is 
     
     
        fixed about a vertical axis. 13. A vehicle, as claimed in claim 1, wherein the source of power comprises an internal combustion engine located below 
     
     
        the well. 14. A vehicle, as claimed in claim 13, and further comprising a service compartment located under the cab and accessible from the outside of the vehicle to one side of the cab, whereby the oil level of the engine can be checked without lifting the well to expose the engine.  .Iadd.15. A self-propelled, low profile vehicle for enabling a driver to carry and maneuver a load over a grade surface comprising, in combination: a vehicle body having a front end and a rear end;   first axle means coupled to the vehicle body and having a first end portion, a second end portion, and an axis of rotation;   second axle means coupled to the vehicle body substantially parallel to the first axle means and having a first end portion, a second end portion, and an axis of rotation, the axes of rotation of the first and second axle means defining a first plane;   a first wheel coupled to the first end portion of the first axle means and having an outer periphery defining a first circle having an upper point;   a second wheel coupled to the second end portion of the first axle means and having an outer periphery defining a second circle having an upper point;   a third wheel coupled to the first end portion of the second axle means and having an outer periphery defining a third circle having an upper point;   a fourth wheel coupled to the second end portion of the second axle means and having an outer periphery defining a fourth circle having an upper point, the upper points of the first, second, third and fourth circles defining a second plane, and the points of the third and fourth circles closest to the first axle means lying in a third plane perpendicular to the second plane;   pivoting means defining a pivot axis located above the first plane and to the rear of the third plane, said pivot axis lying in a fourth plane parallel to the first plane;   a boom mounted on the pivot axis to rotate in an operating plane substantially perpendicular to the first plane, said boom extending cantilever-fashion from the pivot axis over the first axle means to a load-bearing end;   carrying means mounted on the load bearing end for carrying the load;   hydraulic means for moving the boom in the operating plane;   a source of power for moving the vehicle over the grade surface and for supplying power to the hydraulic means;   a cab for the driver positioned entirely on a first side of the operating plane;   a central depressed portion defined in the vehicle body positioned below the boom, said central depressed portion having a lower member extending below the fourth plane for receiving the boom when the boom is pivoted downwardly said pivoting means and said central depressed portion cooperating to define means for enabling the load to be maneuvered below the grade surface; and   a frame structure positioned on the vehicle body above the first plane entirely on a second side of the operating plane opposite the first side of the operating plane, so that the central depressed portion is positioned between the cab and the frame structure said central depressed portion further defining means for enabling the boom to be extensible and retractable therein. .Iaddend.  .Iadd.16. A vehicle, as claimed in claim 15, and further comprising steering means located within the cab and linked to at least two of the wheels for controlling the directional movement of the vehicle, said steering means having an upper point in a fifth plane and wherein the pivot axis is positioned between the second plane and the fifth plane, whereby the vision of the driver is substantially unobstructed when the vehicle is used to carry a load adjacent the grade surface and the center of gravity is maintained at a low level. .Iaddend. .Iadd.17. A vehicle, as claimed in claim 15, wherein the hydraulic means is located at least partially in the central depressed portion, and wherein the source of power is located at least partially below the second plane, whereby the center gravity of the vehicle is lowered. .Iaddend. .Iadd.18. A vehicle, as claimed in claim 15, wherein the boom comprises a fixed section; a first movable section telescoped inside the fixed section; a second movable section telescoped inside the first movable section; a first pulley movable with the first movable section; first chain means looped around the first pulley, said first chain means having a first end connected to the fixed section and a second end connected to the second movable section; a second pulley movable with the first movable section; second chain means looped around the second pulley, said second chain means having a first end connected to the second movable section and a second end connected to the fixed section; hydraulic extension means having a first end connected to the fixed section and a second end connected to the first movable section for moving the first movable section outward and inward with respect to the fixed section, whereby the first pulley and first chain means simultaneously move the second movable section outward as the first movable section is moved outward and the second pulley and second chain means simultaneously move the second movable section inward as the first movable section is moved inward. .Iaddend.  .Iadd.19. A self-propelled, low profile vehicle for enabling a driver to carry and maneuver a load over a grade surface comprising, in combination:   a vehicle body having a front end and a rear end;   first axle means coupled to the vehicle body and having a first end portion, a second end portion, and an axis of rotation;   second axle means coupled to the vehicle body substantially parallel to the first axle means and having a first end portion, a second end portion, and an axis of rotation, the axes of rotation of the first and second axle means defining a first plane;   a first wheel coupled to the first end portion of the first axle means and having an outer periphery defining a first circle having an upper point;   a second wheel coupled to the second end portion of the first axle means and having an outer periphery defining a second circle having an upper point;   a third wheel coupled to the first end portion of the second axle means and having an outer periphery defining a third circle having an upper point;   a fourth wheel coupled to the second end portion of the second axle means and having an outer periphery defining a fourth circle having an upper point, the upper points of the first, second, third and fourth circles defining a second plane, and the points of the third and fourth circles closest to the first axle means lying in a third plane perpendicular to the second plane;   pivoting means defining a pivot axis located above the first plane and to the rear of the third plane, said pivot axis lying in a fourth plane parallel to the first plane;   a boom mounted on the pivot axis to rotate in an operating plane substantially perpendicular to the first plane, said boom extending cantilever-fashion from the pivot axis over the first axle means to a load-bearing end;   carrying means mounted on the load bearing end for carrying the load, said carrying means comprising a support position at the load bearing end of the boom, a fork and a drop block mounted on the support and means for maintaining the drop block at a constant height above the grade surface as the boom is extended and retracted;   hydraulic means for moving the boom in the operating plane;   a source of power for moving the vehicle over the grade surface and for supplying power to the hydraulic means;   a cab for the driver positioned entirely on a first side of the operating plane;   a central depressed portion defined in the vehicle body positioned below the boom, said central depressed portion having a lower member extending below the fourth plane for receiving the boom when the boom is pivoted downwardly whereby the load can be maneuvered below the grade surface; and   a frame structure positioned on the vehicle body above the first plane entirely on a second side of the operating plane opposite the first side of the operating plane, so that the central depressed portion is positioned between the cab and the frame structure and wherein the boom is   
     
     
        extensible and retractable. .Iaddend. .Iadd.20.  A vehicle, as claimed in claim 15, wherein the steering means comprises a steering wheel positioned so that the driver normally faces toward the front end of the vehicle body, so that the line of sight between the driver and the load is substantially unobstructed irrespective of the manner in which the boom is moved in the operating plane. .Iaddend. .Iadd.21. A vehicle, as claimed in claim 19, wherein the carrying means further comprises means for maintaining the fork substantially parallel to the grade surface as the boom is raised and lowered. .Iaddend.  .Iadd.22. A vehicle, as claimed in claim 19, wherein the fork is fixed about a vertical axis. .Iaddend. .Iadd.23. A self-propelled, low profile vehicle for enabling a driver to carry and maneuver a load over a grade surface comprising in combination: a vehicle body having a front end and a rear end;   front axle means coupled to the vehicle body and having first end portion, a second end portion, and an axis of rotation;   rear axle means coupled to the vehicle body substantially parallel to the front axle means and having a first end portion, a second end portion, and an axis of rotation the axes of rotation of the front and rear axle means defining a first plane;   a first front wheel coupled to the first end portion of the front axle means and having an outer periphery defining a first circle having an upper point;   a second front wheel coupled to the second end portion of the front axle means and having an outer periphery defining a second circle having an upper point;   a first rear wheel coupled to the first end portion of the rear axle means and having an outer periphery defining a third circle having an upper point;   a second rear wheel coupled to the second end portion of the rear axle means and having an outer periphery defining a fourth circle having an upper point, the upper points of the first, second, third and fourth circles defining a second plane, and the points of the third and fourth circles closest to the front axle means lying in a third plane perpendicular to the second plane;   pivoting means defining a pivot axis located above the first plane and to the rear of the third plane, said pivot axis lying in a fourth plane parallel to the first plane;   a boom mounted on the pivot axis to rotate in an operating plane substantially perpendicular to the first plane, said boom extending cantilever-fashion from the pivot axis over the front axle means to a load-bearing end;   carrying means mounted on the load bearing end for carrying the load, said carrying means comprising a support position at the load bearing end of the boom, a fork and a drop block mounted on the support and means for maintaining the drop block at a constant height above the grade surface as the boom is extended and retracted;   hydraulic means for moving the boom in the operating plane;   a source of power for moving the vehicle over the grade surface and for supplying power to the hydraulic means;   a cab for the driver positioned entirely on a first side of the operating plane;   a well in the vehicle body positioned below the boom, said well having a lower member extending below the fourth plane for receiving the boom when the boom is pivoted downward toward the front axle means, whereby the load can be maneuvered below the grade surface; and   a load-carrying platform positioned on the vehicle body above the first plane entirely on a second side of the operating plane opposite the first side of the operating plane, so that the well is positioned between the cab and the platform and wherein the boom is extendible and retractable. .Iaddend.