Abstract:
A multi-terrain vertical lift transporter for lifting and transporting loads over various soil conditions and terrain. The lift transporter has a laterally adjustable wheel base to allow it to accommodate loads of varying widths. Further, the lift transporter does not require a counter-weight as the center of gravity of the load is substantially within the wheel base.

Description:
FIELD 
     This invention relates to a self-propelled multi-terrain vertical lift transporter for lifting and transporting loads over various soil conditions and terrain. 
     BACKGROUND OF THE INVENTION 
     Forklift trucks are widely used in a variety of applications and come in many different shapes and sizes. In particular, many forklifts have been designed especially for light duty applications. However, these light duty forklifts typically have a fixed wheel base making it difficult to use them in narrow passageways and at the same time lack the requisite stability to avoid tipping or overturning in response to unbalanced loads or encountering variable terrain. 
     U.S. Pat. No. 4,571,139 issued Feb. 18, 1986 to Moseley et al. discloses a freight handling truck comprising a frame mounted on at least three wheels, a supporting mast, lifting forks and a motor. Of the three wheels, at least one is a driving wheel powered by the motor and the other two wheels are idler wheels, mounted on two horizontally pivotal wheel arms. The pivotal wheel arms are powered by the motor to pivot them laterally to either widen or narrow their lateral extent. The pivotal wheel arms are also telescopic, allowing them to extend or retract. In the freight handling truck disclosed by Moseley et al. the wheels mounted at the ends of the adjustable wheel arms are not capable of pivoting or re-orienting as the wheel arms pivot. Therefore, the wheels mounted on the adjustable wheel arms are parallel with the path of travel of the device for only one angle of the wheel arms. Thus increased friction occurs when the angle of the wheel arms is changed to different angles. Also, the freight handling truck, as disclosed by Moseley et al., cannot lower a load to the floor if the pivotal wheel arms are in the narrowed position. The freight handling truck disclosed by Moseley et al. is further limited in that it is incapable of performing a tight radius turn. 
     It is, therefore, an object of this invention to provide a lift transporter with improved stability and maneuverability. 
     It is a further object of this invention to provided a lift transporter which is capable of laterally adjusting its wheel base. 
     It is a further object of this invention to provide a lift transporter capable of performing a tight radius turn. 
     It is a further object of this invention to provide a lift transporter which is reduced in weight. 
     SUMMARY OF THE INVENTION 
     The lift transporter of this invention is constructed of a steel frame which houses a motor and the hydraulic systems. Four wheels, two front and two rear, are mounted onto the frame. The two front wheels are mounted on laterally adjustable outriggers which are arranged outside of the lifting forks. The separation of the laterally adjustable outriggers, through the operation of the hydraulic systems, can be widened or narrowed as required. The two rear wheels are mounted on a common axle which is journaled to a post. Thus, the rear wheels are locked together for improved traction and are hydraulically powered. The front and rear wheels are of a sufficient width and tread design to allow the lift transporter to move over various terrain including gravel, sand and mud. 
     The lift platform of the lift transporter may consist of lifting forks, or other lifting implements, all of which can be interchanged simply by lifting one implement off of the horizontal members of the lift carriage and replacing it with another implement. The lift carriage is hydraulically powered to be raised and lowered. 
     The lift transporter is steered utilizing a tiller handle. Mounted to the neck of the tiller handle are the controls for raising and lowering the lift assembly, moving the lift transporter forward and reverse, and widening and narrowing the laterally adjustable outriggers. Also, the tiller handle and the rear wheel assembly are constructed to pivot through a wide range thereby allowing the lift transporter to perform tight radius turns. 
     The improved lift transporter of this invention does not require a counter weight as the center of gravity of any load is substantially within the wheels and thus cannot tip the unit. 
     Other objects and advantages of the invention will become clear from the following detailed description of the preferred embodiment, which is presented by way of illustration only and without limiting the scope of the invention to the details thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention itself both as to organization and method of operation, as well as additional objects and advantages thereof, will become readily apparent from the following detailed description when read in connection with the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of the lift transporter with lifting forks as the lift platform; 
     FIG. 2 is a front view of the lift transporter with the outriggers in a narrowed position; 
     FIG. 3 is a front view of the lift transporter with the outriggers in a widened position; and 
     FIG. 4 is a rear view of the lift transporter with the outriggers in a narrowed position and the tiller handle has been removed for clarity. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Throughout the figures, like elements are indicated by like reference numbers. Referring to FIGS. 1 to  4 , the lift transporter  10  includes a frame  11  which houses a motor  18  and the hydraulic systems (not shown). Frame  11  is comprised of vertical support portions  12 , horizontal support portion  13 , mast portions  14  and base portion  16 . Slidably mounted to the underside of base portion  16  of frame  11  are laterally adjustable outriggers  22 . The rear wheel assembly  24  is pivotally mounted to the rear of base portion  16  of frame  11 . 
     The rear wheel assembly  24  comprises rear wheels  54 , wheel axle  56 , wheel post  58 , tiller plate  60 , tiller post  62  and tiller handle  64 . The rear wheels  54  are mounted on a common wheel axle  56  which is operatively coupled to the wheel post  58 . The wheel post  58  is mounted to the lower surface of the tiller plate  60 . The tiller post  62  is mounted on the upper surface of tiller plate  60 . The tiller post  62  is received in post receptacle  66  located at the rear junction of the base portions  16  of the frame  11 . The tiller post  62  is pivotally secured in the post receptacle  66  to allow the rear wheel assembly  24  to rotate about tiller post  62 . The tiller handle  64  is mounted on the upper surface of tiller plate  60  such that the rear wheels  54  and the tiller handle  64  are parallel. The control levers  70  are mounted on the neck of the tiller handle  64 . The control levers  70  operate to actuate the various cylinders that are used in the operation of the lift transporter  10 . The rear wheels  54  are operatively coupled to motor  18  by any suitable power transmission means. 
     Mounted at the distal ends of the laterally adjustable outriggers  22  are the idler wheels  30 . The idler wheels  30  are preferably mounted on a fixed axis and so do not turn to either side. The laterally adjustable outriggers  22  are operatively coupled to the hydraulic cylinder  32 . Hydraulic cylinder  32  operates to widen and narrow the laterally adjustable outriggers  22 . 
     The lift assembly  34  comprises the lift carriage  36 , hydraulic cylinder  38 , chain  40 , rotatable sprocket  68  and lift implement  42 . The lift carriage  36  is I-shaped with upper horizontal member  44 , lower horizontal member  46  and vertical member  48  being mounted between the upper and lower horizontal members  44  and  46 . The lift carriage  36  is slidably mounted to mast portions  14  of frame  11 . Mounted on the ends of horizontal members  44  and  46  are front and rear guide rollers  50  which engage mast portions  14 . Rollers (not shown) which are mounted inside each end of the upper and lower horizontal members  44  and  46 , protrude slightly to roll over the inside of the mast portions  14 . A rotatable sprocket  68  is mounted to the top of hydraulic cylinder  38  with a chain  40  engaging the rotatable sprocket  68 . One end of chain  40  is secured to the vertical member  48  of the lift carriage  36 , and the other end of chain  40  is secured to the horizontal support portion  13  of frame  11 . Thus, the lift carriage  36  is raised and lowered through the operation of hydraulic cylinder  38 . 
     The lift implement  42  is detachably secured to the horizontal members  44  and  46  of the lift carriage  36  by upper and lower hook braces  52   a  and  52   b . The lift implement  42  may take on a variety of forms, including, but not limited to forks, a bucket and a large planar surface. A lift implement of one form may be substituted for a lift implement of another form by lifting hook braces  52   a  and  52   b of lift implement  42  from horizontal members  44  and  46 , respectively, and placing the hook braces of an alternate lift implement onto horizontal members  44  and  46 . 
     The motor  18  is sufficiently powerful to drive either the rear wheels  54  while under a load of about 500 lbs, the hydraulic systems (not shown) to operate the laterally adjustable outriggers  22  to widen or narrow them when the lift transporter  10  is under a load of about 500 lbs, or the hydraulic systems to allow the lift transporter  10  to raise a load of about 500 lbs. 
     In operation, a user steers the lift transporter  10  through tiller handle  64 . Tiller handle  64  can be pivoted in the horizontal plane parallel to the ground through a range of about 220°. A user utilizes control levers  70  to actuate the various hydraulic cylinders necessary to operate the lift transporter  10 . Hydraulic cylinder  38  is actuated to raise and lower the lift carriage  36  and hydraulic cylinder  32  is actuated to widen and narrow the laterally adjustable outriggers  22 . The control levers  70  also regulate the speed and direction of the lift transporter  10  when engaging the power transmission means of the rear wheels  54 . The control levers  70  are designed such that only one of the rear wheel assembly  24 , the laterally adjustable outriggers  22  or the lift assembly  34 , may be in operation at one time. 
     To lift a load, the lift transporter  10  is directed using tiller handle  64 . The rear wheels  54  are engaged, through the control levers  70 , to propel the lift transporter  10  to the target location. At any point, the rear wheels  54  may be disengaged and the laterally adjustable outriggers  22  may be widened or narrowed. The laterally adjustable outriggers  22  may be narrowed to accommodate a narrow load or pass through a narrow space, or the laterally adjustable outriggers  22  may be widened to accommodate a wider load. The adjustment of the laterally adjustable outriggers is effected through the actuation of hydraulic cylinder  32  through the control levers  70 . Once the lift implement  42  has been positioned under the load, the user utilizes control levers  70  to raise the load. Hydraulic cylinder  38  is actuated to extend its piston, thereby raising the lift carriage  36  to which the lift implement  42  is detachably secured. When the load has been raised to the appropriate height, the laterally adjustable outriggers  22  may be adjusted once again. The load on the lift implement  42  is within the wheel base of the lift transporter  10 , preventing tipping of the lift transporter  10  by an imbalance in the load. 
     It will be appreciated by those skilled in the art that the lift transporter of this invention is distinguished by its versatility, simplicity, and efficiency. Moreover, the design of the lift transporter precludes the need for a counter-weight thereby decreasing the weight of the lift transporter making it easier to maneuver and control. 
     Furthermore, it will be understood that the motor, hydraulic cylinders, hydraulic systems, etc. used throughout this invention may be of any desired design according to the knowledge of those skilled in the art and operate in conventional fashion to achieve the intended result. Indeed, the hydraulic cylinders, may be replaced with electric or pneumatic equipment, if so desired. 
     Although the present invention has been described in detail with reference to one preferred embodiment, it will be clearly understood that this is by way of illustration only. Many variations and alternative embodiments of the invention will now be apparent to those skilled in the art, and are not to be excluded from the scope of the invention, which is to be determined only by the appended claims, as set forth below.