BACKGROUND OF THE INVENTION Conventional coil carriers must lift and carry steel coils which are relatively large and heavy. While exact coil size may vary, a steel coil is typically on the order of 2.2 meters in diameter and 2.2 meters in width and weighs on the order of 30 to 40 tons. When maneuvering heavy loads, such as steel coils, the vehicle must be designed such that it will not tip under the weight of the heavy load.

In order to prevent tipping, conventional coil carriers typically employ a relatively long wheelbase and substantial dead vehicle weight to counterbalance the load. As a result, conventional coil carriers require substantial room to maneuver into position to engage, lift, and stack coils. Rows or stacks of coils must be spaced apart a sufficient distance to provide an aisle of a width which permits such extensive maneuvering of the carrier into appropriate contact with the coils.

OBJECTS OF THE INVENTION It is a primary aim of the present invention to provide a vehicle which may be operated in a relatively narrow aisle to lift and retract a load such as a steel coil. A related object is to facilitate a relatively dense pack of coil stacks to minimize storage space and costs associated therewith.

An additional object is to provide a vehicle which may be readily maneuvered by an operator.

A further object is to provide a vehicle that may be used to lift objects either to the side or to the front of the vehicle and which may be used to move the load over a broad range of motion.

SUMMARY OF THE INVENTION The present invention provides a load handling vehicle having a mainframe supported on a plurality of wheels and a lift apparatus which is rotatably coupled to the mainframe by a turntable. The turntable supports a counterweight and the lift apparatus which may be used to engage and lift a load, such as a coil. Inasmuch as the lift apparatus is pivotable relative to the main frame, the lift apparatus can lift and engage a load disposed forward the vehicle when the lift apparatus is in a position substantially parallel to the mainframe, or a load disposed alongside the vehicle when the lift apparatus is positioned substantially perpendicular to the mainframe. The lift apparatus is coupled to upright supports secured to the turntable and includes a pair of lift arms pivotally coupled to the upright supports at one end and to a mast and engagement probe at the opposite end.

Movement of the lift arms and, accordingly, the mast and engagement probe in a vertical plane is provided by means of a pair of hydraulic lifting cylinders coupled to the lift arms, respectively. The tilt angle of the mast is controlled by a second pair of hydraulic cylinders pivotally coupled to the upper end of the mast at one end and to the upright support on the turntable at the other end.

According to an important feature of the invention, the engagement probe is retractably mounted in the mast by a rack and pinion gear controlled by a hydraulic motor. Thus, the engagement probe may be fully retracted within the mast and the mast positioned within the footprint of the wheelbase of the vehicle. Accordingly,

the vehicle may be advanced in an aisle between two stacks of coils with the turntable rotated such that the mast disposed to the side or front of the vehicle, while maintaining the mast and engagement probe within the footprint of the vehicle. The mast may then be raised to an appropriate level adjacent the coil, the engagement probe advanced to engage the coil, the coil lifted, and the turntable rotated, if desired, to move the mast and coil to an alternate position for transportation. In this way, the vehicle offers versatility in handling coils, and may be effectively utilized in an area requiring a minimal amount of floor space beyond the footprint of the wheelbase. As a result, the coils may be stacked in relatively close rows, minimizing the floor space required for storage or more efficiently utilizing the floor space available, and, accordingly, minimizing storage costs.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view of a load handling vehicle constructed in accordance with teachings of the invention showing the lift apparatus in the lowered position in solid lines and in the raised position in phantom lines.

FIG. 2 is a top plan view of the vehicle of FIG. 1 showing the lifting apparatus in the forward position in solid lines and the side, perpendicular position in phantom lines.

FIG. 3 is a fragmentary view of the vehicle and lifting apparatus of FIG. 1 showing the mast and engagement probe in the vertical position in solid lines and in the rearward tilting or carrying position, and the forward tilting or unloading position, both in phantom.

FIG. 4 is a fragmentary front view of the vehicle of FIG. 1 showing the lifting apparatus in the lowered, side position with the engagement probe extended in solid lines and the engagement probe in the retracted position

in phantom lines, and the lifting apparatus in the raised, side position in phantom lines.

FIG. 5A is a front view of the mast.

FIG. 5B is a fragmentary cross-sectional view of the lifting apparatus taken along line 5B-5B IN FIG. 5A.

FIG. 6 is a fragmentary front view of the vehicle of FIG. 1 showing the lifting apparatus in a side, slightly raised position with the probe extended in solid lines and the probe retracted in phantom lines, and the lifting apparatus and a coil in a raised position with the mast vertical and tilted backwards in phantom lines.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning to FIG. 1 of the drawings, there is shown a vehicle 20 embodying the teachings of the invention. The vehicle 20 includes a cab 40 supported on a mainframe 22 comprising a forward frame portion 24 supported on a plurality of wheels 26a, 28a, 26b, 28b, and a rearward frame portion 30 supported on wheels 32a, 32b. For ease of understanding, components, subassemblies and the like which have a symmetrical counterpart on an opposite side of the vehicle are numbered such that from the perspective of the driver (i. e., looking forward from the cab, as will be described below), the right side is denoted by the lowercase letter"a"and the left side by the lowercase letter"b."Because of the relatively heavy loads intended to be lifted and to provide enhanced weight carrying capability, each support point is preferably arranged as a dual-wheel system, having a wheel pair with conventional air inflated tires mounted thereon. As may be seen in FIG. 2, the forward wheels 26a, 28a, 26b, 28b, and rearward wheels 32a, 32b are preferably arranged in pairs.

Returning to FIG. 1, the forward and rearward frame portions 24,30 are pivotally coupled by joints 36 along the steering pivot axis 38. Referring again to FIG. 2, the rearward wheels 32a, 32b are spaced relatively close

as compared to the pairs of forward wheels 26a, 28a, 26b, 28b. Thus, the mainframe 22 is designed such that the forward wheelbase is arranged as an isosceles triangle configuration with the steering pivot axis 38. The rearward frame portion 30 is preferably designed to pivot about the steering pivot axis on the order of 50° from center in either direction (as indicated by arcs A and B) in order to steer and direct the forward frame 24. A pair of hydraulic steering cylinders (not shown) are disposed between the forward and rearward frame portions 24,30 to steer the vehicle 20 by methods known to those in the art.

In the currently preferred embodiment, the vehicle 20 is intended to be completely self-propelled. To this end, the rear wheels 32a, 32b are preferably driven through a suitable gear train and transmission in a conventional manner from a self-contained engine operated from the operator's cab 40. Nevertheless, it can be readily appreciated that such a vehicle 20 could, if desired, be towed in a tractor trailer arrangement.

Referring to FIG. 1, the vehicle 20 is further provided with a lift apparatus 50 for engaging, lifting, and carrying a load, such as a steel coil. According to an important feature of the invention, the vehicle may be disposed between adjacent stacks of coils, as shown in FIG. 6, when the operator engages and lifts the coil. In order to permit this operation in relatively close conditions, the lift apparatus 50 is coupled to the mainframe 22 by a turntable 52. A support 54 is secured to the turntable 52 and extends upward therefrom as shown in FIGS. 1,4, and 6. The lift apparatus 50 is coupled to the upwardly extending support such that, as the turntable is rotated, the lift apparatus 50 may be pivoted to the side of the vehicle 20, as shown in FIGS.

4 and 6.

The lift apparatus 50 includes a pair of substantially longitudinally extending lift arms 56a, 56b

which may be rigidly connected together near their centers by a stabilizing crossbeam (not shown) to form an H-shaped lift frame. The lift arms 56a, 56b are pivotally coupled to the upright support 54 by pivot pins 58a, 58b or the like at one end. The opposite ends of the lift arms 56a are coupled to a mast 60 by pivot pins 62a, 62b. In order to engage, lift and carry a coil, an engagement pin 61 is coupled to the mast 60 and extends outwardly therefrom as shown in FIG. 1.

Turning now to consideration for the primary lifting capabilities of the lift apparatus 50, i. e., the raising and lowering of the lift arms 56a, 56b and the mast 60 coupled thereto, a pair of hydraulic lifting cylinders 64a, 64b are trunion mounted to the corresponding right and left lift arms 56a, 56b along their central area by pivot pins 66a, 66b, or the like. The pistons of the lifting cylinders 64a, 64b are pivotally mounted by pivot pins 67a, 67b or the like at surfaces 68a of the upright support 54. Accordingly, as these lift cylinders 64a, 64b are extended, the downward force presses on the surfaces 68a, 68b and a corresponding upward force raises the lift arms 56a, 56b to swing the front or distal end of the lift arms 56a, 56b and the mast 60 vertically upwards, the rear or proximal end of the lift arms 56a, 56b pivoting at pivot pins 58 at the support 54.

Conversely, as the lifting cylinders 64a, 64b are retracted, the lift arms 56a, 56b swing downwardly, lowering the mast 60.

To control the angle of the mast 60 relative to the lift arms 56a, a pair of hydraulic cylinders 70a, 70b are connected at their piston ends to the upper end of the mast 60 at pivot pins 72a, 72b. The opposite ends of these reach and retract cylinders 70a, 70b are coupled to the upper end of the upright support 54 via pivot pins 74a, 74b. Accordingly, extending and retracting the pistons of the cylinders 70a, 70b varies the vertical angle of the mast 60 as shown in FIG. 3. Preferably, the

upper end of the mast 60 may be tilted on the order of 10° toward the rear of the vehicle to tilt the engagement probe 61 upward to lift and move a coil as shown by arc C and in phantom lines. Conversely, the mast 60 may preferably be tilted forward in the order of 5° to tilt the engagement probe 61 downward for disengagement of a coil as shown by arc D and in phantom lines.

According to another important feature of the invention, the vehicle 20 may be advanced in an aisle between relatively close stacks of coils, as shown in FIG. 6. In order to facilitate this movement, the engagement probe 61 may be fully retracted to the position shown in phantom at 61a in FIGS. 4 and 6. It will thus be appreciated by those skilled in the art that the stacks of coils may be disposed closer than has been typically possible, providing for much more dense storage and more efficient utilization of storage space.

In order to retract the engagement probe 61 into and through the mast 60, a rack and pinion mechanism is provided. As shown in FIGS. 5A and 5B, a rack 80 is provided along one longitudinal surface of the probe 61.

An engaging pinion gear 82 is rotatably mounted in the mast 60 to engage the rack 80. Rotation of the pinion gear 82, and, accordingly, the rack 80 and probe 61, is provided by a hydraulic motor 84, which may be controlled by the operator from the cab 40 of the vehicle.

It will thus be appreciated that the lift apparatus 50 may be used to engage and lift a coil when the engagement probe 61 is in the forward portion of the vehicle, as shown in FIGS. 1 and 2, or when the lift apparatus is substantially perpendicular to the forward frame portion 24, as shown in FIGS. 4 and 6. In a preferred form of operation, the vehicle 20 may be advanced in an aisle between two stacks of coils 90a, 90b, as shown in FIG. 6. In this regard, the aisle may be relatively narrow inasmuch as the engagement probe 61 may be fully retracted into the mast 60 (as shown in

phantom position 61a in FIG. 4) during the maneuvering of the vehicle 20.

Once in a desired position adjacent a coil 92 to be moved, the hydraulic lifting cylinder 64a, 64b may be actuated to lift the lift arms 56a to a required height to engage the coil 92, as shown in FIG. 6. The hydraulic motor 84 may then be actuated to rotate the pinion gear 82 engaging the rack 80 to extend the engagement probe 61 into the hole of the coil 92 (i. e., from the position shown as 61a in FIG. 6 to the position shown in solid lines). The hydraulic lifting cylinders 64a, 64b may then be further actuated to lift the coil 92 (shown as 92a) to the position in phantom in FIG. 6. For purposes of transporting the coil 92, hydraulic cylinders 70a, 70b may then be actuated to tilt the mast 60 and engagement probe 61 upward and rearward to more securely hold the coil 92 for transport (as shown in phantom 92b).

Once the coil 92 is in a desired location for unloading, the hydraulic cylinders 70a, 70b may be actuated to return the mast 60 to vertical and the engagement probe 61 to horizontal. The hydraulic lifting cylinders 64a, 64b may then be lowered to lower the lift arms 56a, 56b, mast 60 and engagement probe 61 to lower the coil 92 into position. The hydraulic cylinders 70a, 70b may then be actuated to lower the tip of the engagement probe 61 for unloading. Alternately, the hydraulic motor 84 may be actuated to rotate the pinion gear 82 engaging the rack 80 to retract the engagement probe 61 within the mast 60.

In order to effectively counterbalance the weight of the coil 92 on the turntable 52, regardless of the rotated position of the lift apparatus 50 on the turntable, the a counterweight 94 is preferably provided.

As may be seen in FIGS. 1,4 and 6, the counterbalance 94 is preferably coupled to the upright support 54 on the turntable 52 and extends from the upright support 54 in the direction opposite the lift apparatus 50. In the

embodiment illustrated, the cab 40 is conveniently located over the counterweight 94, such that the cab 40 and the operator's own weight likewise provide counterbalance to a coil 92. While the cab 40 might be disposed in an alternate location on the vehicle 20, when provided in the position shown, providing the operator a good vantage point from which he can readily view the movements of the lift apparatus 50 and engagement of the probe 61 with a coil 92.