Straddle carrier

Claim 2

A straddle carrier consisting of a pair of spaced parallel elongated frame members adapted to straddle a load; a single vertically disposed arch member connecting said frame members together adjacent one end thereof; diagonally disposed leg members connecting the top of the arch member to said frame members intermediate the ends thereof forming an open ended vertically unobstructed bay between said frame members rearwardly of said arch member; ground wheels flexibly and steerably mounted on the undersides of the frame members; means for driving certain of said wheels; a rectangular load lifting beam disposed between the frame members; extensible upright support means spaced along each frame member, and flexible lifting means guided over the upper end of each support means and engaging the four corners of the lifting beam for raising and lowering the lifting beam; means at the four corners of the lifting beam for securing the same to a load; means adjacent the arch member for guiding the lifting beam during its ascent and descent; and means controlling the lifting beam raising and lowering means whereby the four corners of said beam will be simultaneously raised or lowered equal amounts notwithstanding the relative weights on said respective corners in order to maintain the beam always parallel with the said frame members.

Claim 3

A straddle carrier consisting of a pair of spaced parallel elongated frame members adapted to straddle a load; a single vertically disposed arch member connecting said frame members together adjacent one end thereof; diagonally disposed leg members connecting the top of the arch member to said frame members intermediate the ends thereof forming an open ended vertically unobstructed bay between said frame members rearwardly of said arch member; ground wheels flexibly and steerably mounted on the undersides of the frame members; means for driving certain of said wheels; a rectangular load lifting beam disposed between the frame members; extensible upright support means spaced along each frame member, and flexible lifting means guided over the upper end of each support means and engaging the four corners of the lifting beam for raising and lowering the lifting beam; means at the four corners of the lifting beam for securing the same to a load; means adjacent the arch member for guiding the lifting beam during its ascent and descent; and means controlling the lifting beam raising and lowering means whereby the four corners of said beam will be simultaneously raised or lowered equal amounts notwithstanding the relative weights on said respective corners in order to maintain the beam always parallel with the said frame members.

Claim 4

A straddle carrier consisting of a pair of spaced parallel elongated frame members adapted to straddle a load; a single vertically disposed arch member connecting said frame members together adjacent one end thereof; diagonally disposed leg members connecting the top of the arch member to said frame members intermediate the ends thereof forming an open ended vertically unobstructed bay between said frame members rearwardly of said arch member; ground wheels flexibly and steerably mounted on the undersides of the frame members; means for driving certain of said wheels; a rectangular load lifting beam disposed between the frame members; extensible upright support means spaced along each frame member, and flexible lifting means guided over the upper end of each support means and engaging the four corners of the lifting beam for raising and lowering the lifting beam; means at the four corners of the lifting beam for securing the same to a load; means adjacent the arch member for guiding the lifting beam during its ascent and descent; and means controlling the lifting beam raising and lowering means whereby the four corners of said beam will be simultaneously raised or lowered equal amounts notwithstanding the relative weights on said respective corners in order to maintain the beam always parallel with the said frame members.

Claim 5

In a carrier as set forth in claim 1, said driving means comprising drive motors mounted in the hubs of one end wheel of each frame member; an engine driven variable displacement pump mounted on one frame member, flexible piping connecting the pump with said motors respectively; a cab mounted on the outer face of the top of said arch member; and means in said cab for controlling said pump.

Claim 6

In a carrier as set forth in claim 1, said load lifting beam comprising a rectangular frame; a transverse guide bar extending through slotted openings in the lifting beam so as to be shiftable fore-and-aft and laterally with respect to the lifting beams; rollers carried by the ends of the guide bar; said guide bar being disposed near the end of the lifting beam adjacent to the arch member; an A-frame extending from the guide bar within the lifting frame and having its apex terminating adjacent the opposite end of the lifting beam; a double-acting hydraulic cylinder connecting the said opposite end of the lifting beam to the apex of the A-frame and adapted to impart relative movement of the A-frame and lifting beam in a fore-and-aft direction; other double-acting hydraulic cylinders connecting the guide bar and the adjacent end of the lifting beam adapted to impart relative movement of thE A-frame and lifting beam in a lateral direction; a cab mounted on the outer face of the top of said arch member; and means in said cab for controlling said cylinders.

Claim 7

In a carrier as set forth in claim 3, a lifting beam control comprising an hydraulic circuit including a tank, a pump, said first and other double-acting hydraulic cylinders, and normally closed hydraulic valves adapted when open to allow fluid to flow from one end of their respective double-acting hydraulic cylinders to the other end, and when closed to hold the lifting beam in adjusted position.

Claim 8

In a carrier as set forth in claim 4, said normally closed hydraulic valves having controls, an electric circuit including the controls of the normally closed hydraulic valves, and a single switch which when closed will cause the said controls to be energized simultaneously, thereby allowing the lifting beam to ''''float'''', and when open will allow the said controls to be operated individually.

Claim 9

In a carrier as set forth in claim 1, said load lifting beam comprising a rectangular frame; a transverse guide bar extending through slotted openings in the lifting beam so as to be shiftable laterally with respect to the lifting beams; rollers carried by the ends of the guide bar; said guide bar being disposed near the end of the lifting beam adjacent to the arch member; an A-frame extending from the guide bar within the lifting frame and having its apex terminating adjacent the opposite end of the lifting beam; double-acting hydraulic cylinders connecting the lifting beam to the apex of the A-frame and to the transverse guide respectively adapted to impart relative movement of the A-frame and transverse guide in a lateral direction; a cab mounted on the outer face of the top of said arch member; and means in said cab for controlling said cylinders.

Claim 10

In a carrier as set forth in claim 1, said means for guiding said lifting beam comprising telescoping tracks on the arch diagonal leg members receiving rollers on the lifting beam, said tracks being movable vertically in guides disposed adjacent the tops of the leg members, said tracks being of such height that as long as the lifting beam is operating below the top of the arch member no movement of the tracks will occur, but when the lifting beam is elevated above the arch member the rollers will engage caps at the tops of the tracks and will elevate the tracks in their guides with the lifting beam; and sockets on the carrier frame members below the tracks normally receiving the lower ends of the tracks.

Claim 11

In a carrier as set forth in claim 1, said lifting beam raising and lowering means comprising independent free double-acting hydraulic cylinders having their lower ends connected by self-aligning bearings to the frame members adjacent the corners of the lifting beam; said cylinders adjacent the arch member being loosely confined in and extending freely through openings therefor in the upper ends of the diagonal brace members; channel-shaped columns extending upwardly from the frame members at the end opposite from the arch member, said channels loosely confining the said cylinders at the end of the frame members opposite from the arch member, and having straps across their upper ends for preventing the related cylinders from falling inwardly under no-load conditions; upwardly movable rams in said cylinders respectively; pulleys mounted on the upper ends of the rams respectively; cables connected with the four corners of the lifting beam respectively and extending over said pulleys with their outer ends adjustably secured to anchors on the brace members and said columns respectively, whereby as the rams are simultaneously activated the corners of the lifting beam will be simultaneously correspondingly vertically moved; said cylinders and rams normally leaning inwardly at their upper ends, and being free to equalize the forces acting on the lifting beam and anchors through said cables without subjection to any bending loads.

Claim 12

In A carrier as set forth in claim 1, said controlling means comprising a fluid circuit including a fluid tank, a pump, an operator-controlled valve, and a flow divider; said divider dividing the fluid delivered thereto into four substantially equal parts each of which parts is delivered to a related check valve at the lowe end of its related flexibly mounted hydraulic cylinder to move its related ram; said check valves having pilot pistons therein adapted to open when fluid is passing thereto, said fluid escaping through said check valves and passing back to the tank, and said pistons closing when no fluid pressure is exerted thereon, thereby stopping movement of the related ram; said check valves discharging into the upper and lower ends of the hydraulic cylinders, electric control means for maintaining equal ram extension when ascending, descending or when stationary; whereby the operator may control the speed of ascent and descent of the lifting beam by controlling the speed of the pump.

Claim 13

In combination with a carrier as set forth in claim 9, means for sensing uneven extensions of the rams due to variations in load on the four corners of the lifting beam, comprising cables each having one end connected to a ram respectively, said cable being threaded through a sheave at the base of the related cylinder through a sensor, through a second sheave at the base of an adjacent cylinder, over a third sheave at the top of the ram of the adjacent cylinder, and under a fourth sheave attached to the adjacent corner of the lifting beam, its other end being attached to the ram of the adjacent cylinder, whereby as the lifting beam is elevated the cable will be paid out between the fourth and third sheaves twice as fast as the increase in distance between the third and second sheaves, the tension on the cable remaining constant as long as the rams extend equal amounts, but if one ram should extend more than the other, the variation in tension on the cable will be detected by the sensor and the related valve will open allowing fluid to escape from the related cylinder, allowing the related ram to move until the cable tension changes thereby permitting the sensor to return to neutral position.

Claim 14

In a carrier as set forth in claim 10, said sensor comprising a base, a swingable lever pivoted at one end on the base, a pair of spaced pulleys journaled on the lever; said cable passing under one pulley, between and over the other pulley; microswitches on the base disposed at opposite sides of the lever one of which is adapted to be actuated as the lever is swung from central neutral position by variation in tension in the cable to a position over said one microswitch; spring means normally urging the lever to overcome the cable tension; said valves being solenoid controlled valves; and an electric circuit including a battery, said valves, and said microswitches.

Claim 15

In a wheeled vehicle, a load lifting beam comprising a rectangular frame; a transverse guide bar extending through slotted openings in the lifting beam so as to be shiftable fore-and-aft and laterally with respect to the lifting beams; rollers carried by the ends of the guide bar; said guide bar being disposed near one end of the lifting beam; an A-frame extending from the guide bar within the lifting frame and having its apex terminating adjacent the opposite end of the lifting beam; means for guiding said lifting beam; means for raising and lowering the lifting beam; a double-acting hydraulic cylinder connecting the said opposite end of the lifting beam to the apex of the A-frame and adapted to impart relative movement of the A-frame and lifting beam in a fore-and-aft direction; other double-acting hydraulic cylinders connecting the guide bar and the adjacent end of the lifting beam adapted to impart relative movement of the A-frame and lifting beam in a lateral direction; and means for controlling said cylinders.

Claim 16

In a wheeled vehicle, a load lifting beam comprising a rectangular frame; a transverse guide bar extending through slotted openings in the lifting beam so as to be shiftable fore-and-aft and laterally with respect to the lifting beams; rollers carried by the ends of the guide bar; said guide bar being disposed near one end of the lifting beam; an A-frame extending from the guide bar within the lifting frame and having its apex terminating adjacent the opposite end of the lifting beam; means for guiding said lifting beam; means for raising and lowering the lifting beam; a double-acting hydraulic cylinder connecting the said opposite end of the lifting beam to the apex of the A-frame and adapted to impart relative movement of the A-frame and lifting beam in a fore-and-aft direction; other double-acting hydraulic cylinders connecting the guide bar and the adjacent end of the lifting beam adapted to impart relative movement of the A-frame and lifting beam in a lateral direction; and means for controlling said cylinders.

Claim 17

In a vehicle as set forth in claim 12, said means for guiding said lifting beam comprising tElescoping tracks on vehicle receiving said rollers, said tracks being movable vertically in guides and being of such height that as long as the lifting beam is operating below the tops of the tracks no moment of the tracks will occur, but when the lifting beam is elevated above the tops of the tracks the rollers will engage caps at the tops of the tracks and will elevate the tracks in their guides with the lifting beam; and sockets on the carrier vehicle below the tracks normally receiving the lower ends of the tracks.

Claim 18

In a vehicle as set forth in claim 12, said lifting beam raising and lowering means comprising independent upwardly disposed free double-acting hydraulic cylinders having their lower ends connected by self-aligning bearings to the vehicle adjacent the corners of the lifting beam; said cylinders at one end of the vehicle being loosely confined in and extending freely through openings therefor in the upper end of the vehicle frame; channel-shaped columns extending upwardly from the vehicle at the opposite end of the lifting beam, said channels loosely confining the said cylinders at the said end of the vehicle, and having straps across their upper ends for preventing the related cylinders from falling inwardly under no-load conditions; upwardly movable rams in said cylinders respectively; pulleys mounted on the upper ends of the rams respectively, cables connected with the four corners of the lifting beam respectively and extending over said pulleys with their outer ends adjustably secured to anchors on the frame and the said columns respectively, whereby as the rams are simultaneously activated the corners of the lifting beam will be simultaneously correspondingly vertically moved; said cylinders and rams normally leaning inwardly at their upper ends, and being free to equalize the forces acting on the lifting beam and anchors through said cables without being subjected to any bending loads.

Claim 19

In a vehicle as set forth in claim 12, said controlling means comprising a fluid circuit including a fluid tank, a pump, an operator-controlled valve, and a flow divider, said divider dividing the fluid delivered thereto into four substantially equal parts, each of which parts is delivered to a related check valve at the lower end of its related hydraulic cylinder to move its related ram; said check valves having pilot pistons therein adapted to open when fluid is passing thereto, said fluid escaping through said check valves and passing back to the tank, and said pistons closing when no fluid pressure is exerted thereon, thereby stopping movement of the related ram; said check valves discharging into the upper and lower ends of the hydraulic cylinders whereby the operator may control the speed of ascent and descent of the lifting beam by controlling the speed of the pump.

Claim 20

In combination with a vehicle as set forth in claim 15, means for sensing uneven extensions of the rams due to variations in load on the four corners of the lifting beam, comprising cables each having one end connected to a ram respectively, said cable being threaded through a sheave at the base of the related cylinder through a sensor, through a second sheave at the base of an adjacent cylinder, over a third sheave at the top of the ram of the adjacent cylinder, and under a fourth sheave attached to the adjacent corner of the lifting beam, its other end being attached to the ram of the adjacent cylinder, whereby as the lifting beam is elevated the cable will be paid out between the fourth and third sheaves twice as fast as the increase in distance between the third and second sheaves, whereby the tension on the cable will remain constant as long as the rams extend an equal amount, but if one ram should extend more than the other, the changed tension on the cable will be detected by the sensor and the related valve will open allowing fluid to escape from the related cylinder, allowing the related ram to move until the cable tension changes, thereby permitting the sensor to return to Neutral position.