Abstract:
A vehicle having a first chassis and a second chassis movable relative to the first chassis includes a mechanism configured for moving the first chassis relative to the second chassis. The mechanism includes first and second connecting members, each connecting member connecting one side of the first chassis with an opposite side of the second chassis, and each connecting member being pivotable relative to the first or second chassis to allow the first chassis to move relative to the second chassis in a first direction about a point on a first side of the second chassis and in a second direction about a point on a second side of the second chassis.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    Not applicable. 
       FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND 
       [0003]    This disclosure relates generally to the field of vehicles. 
         [0004]    Tractors and other types of vehicles, such as articulated vehicles and skid loaders, are used in agriculture and construction works. To be more effective, such vehicles typically require increased maneuverability. 
         [0005]    Tractors, for example, are fitted with smaller front wheels compared to rear wheels for increased maneuverability. Articulated vehicles typically require a longer wheelbase between the front and rear wheels or smaller wheels to be more maneuverable. Some vehicles with short wheelbases, such as skid loaders, employ skidded steering for increased maneuverability, which can damage the ground as well as the tires. 
         [0006]    Embodiments of the invention provide a vehicle which provides increased maneuverability, overcomes or ameliorates one or more of the disadvantages or problems described above, or which at least provides the consumer with a useful or commercial choice. 
         [0007]    It will be clearly understood that any reference herein to background material or information, or to a prior publication, does not constitute an admission that any material, information or publication forms part of the common general knowledge in the art, or is otherwise admissible prior art, whether in Australia or in any other country. 
       SUMMARY 
       [0008]    According to one aspect of the invention, there is provided a vehicle comprising:
       a. a first chassis;   b. a second chassis movable relative to the first chassis; and   c. moving means for moving the first chassis relative to the second chassis;   d. the moving means comprising first and second connecting members, each connecting member connecting one side of the first chassis with an opposite side of the second chassis, and each connecting member being pivotable relative to the first or second chassis to allow the first chassis to move relative to the second chassis in a first direction about a point on a first side of the second chassis and in a second direction about a point on a second side of the second chassis.       
 
         [0013]    Advantageously, the connecting members enable the vehicle to be more maneuverable. In particular, the connecting members allow the first and second chassis to be freely movable with respect to one another such that the vehicle can easily move around tight bends and corners. An additional benefit is that steering slip may be reduced, typically resulting in less wear on tires and the ground. 
         [0014]    Each connecting member may be configured to be pivotable only relative to a respective one of the first or second chassis when the first chassis moves in the first direction or the second direction. 
         [0015]    The first connecting member may connect a first side of the first chassis to the second side of the second chassis opposite the first side of the first chassis, and the second connecting member may connect a second side of the first chassis to the first side of the second chassis opposite the second side of the first chassis. 
         [0016]    Typically, the connecting members are each disposed generally transversely between the first chassis and the second chassis with respect to a direction of travel along a straight path. Further, the first connecting member may be disposed above the second connecting member. In addition, the connecting members may be non-extendable elongate members. 
         [0017]    In one embodiment, the connecting members are pivotably connected to the first and second chassis by kingpins. The first connecting member may be pivotable about a first kingpin adjacent the second side of the second chassis to allow the first chassis to rotate about the first kingpin and move in the second direction relative to the second chassis. Similarly, the second connecting member may be pivotable about a second kingpin adjacent the first side of the second chassis to allow the first chassis to rotate about the second kingpin and move in the first direction relative to the second chassis. 
         [0018]    The moving means may further comprise actuating means for moving the first chassis relative to the second chassis. The actuator means may be adapted to change the angle between the first and second chassis to thereby steer the vehicle. 
         [0019]    Moreover, hydraulic cylinders may be used to push and/or pull the first chassis relative to the second chassis to change the angle therebetween. In particular, one hydraulic cylinder may be located between a first side of the first chassis and the first side of the second chassis and another hydraulic cylinder may be located between a second side of the first chassis and the second side of the second chassis to thereby move the first chassis relative to the second chassis. The hydraulic cylinders may be double acting hydraulic cylinders. 
         [0020]    According to another aspect of the invention, there is provided a vehicle comprising:
       a. a first chassis;   b. a second chassis movable relative to the first chassis; and   c. moving means for moving the first chassis relative to the second chassis;   d. the moving means comprising first and second connecting members, each connecting member connecting one side of the first chassis with an opposite side of the second chassis, and each connecting member being pivotable relative to the first or second chassis to allow the first chassis to move relative to the second chassis.       
 
         [0025]    Typically, the first connecting member is pivotable about a first point adjacent one side of the second chassis to allow the first chassis to rotate about the first point and move in one direction relative to the second chassis, and the second connecting member is pivotable about a second point adjacent an opposite side of the second chassis to allow the first chassis to rotate about the second point and move in an opposite direction relative to the second chassis. 
         [0026]    According to a further aspect of the invention, there is provided a mechanism for assisting the movement of a vehicle assembly having a first chassis and a second chassis, the mechanism comprising:
       a. a first connection member for connecting a first side of the first chassis with a second side of the second chassis opposite the first side of the first chassis, and   b. a second connecting member for connecting a second side of the first chassis with a first side of the second chassis opposite the first side of the first chassis,   c. each connecting member being pivotable relative to the first or second chassis to allow the first chassis to move relative to the second chassis.       
 
         [0030]    Advantageously, the mechanism may be used to assist the movement of vehicle assemblies of any size. For example, the mechanism may be used in small vehicle assemblies having closely aligned adjacent wheels on each side of the vehicle assembly, such as four wheel drives, tractors, bobcats or the like. The mechanism may also be used assist the movement of a vehicle assembly comprising a motor vehicle and a trailer. Further, the mechanism allows the vehicle to easily move around bends and corners without external steering and actuating means such as differential gears and hydraulic rams. Of course, the mechanism may also be used to assist the maneuvering of large vehicles such as trucks or lorries without the need for differential gears between the drive axles. Preferably, actuating means such as hydraulic rams are used to assist the steering of such large vehicles. 
         [0031]    Typically, the connection members are connected to the first and second chassis by kingpins. The kingpins may be low friction kingpins. The mechanism may further include bearings to assist movement of the connection members about the kingpins. The roller bearings may be tapered roller bearings. 
         [0032]    Further, the connecting members are non-extendable elongate members. The first connecting member may be disposed above the second connecting member. 
         [0033]    Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    One or more preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
           [0035]    a.  FIG. 1  is a top view of a vehicle in accordance with an embodiment of the invention, showing a 45 degree turn in an anti-clockwise direction. 
           [0036]    b.  FIG. 2  is a top view of a vehicle in accordance with an embodiment of the invention, showing a 90 degree turn in a clockwise direction. 
           [0037]    c.  FIG. 3  is a partial side view of a vehicle in accordance with an embodiment of the invention, showing a 90 degree turn in an anti-clockwise direction. 
           [0038]    d.  FIG. 4  is a perspective view of the vehicle of  FIG. 1  with parts of the vehicle removed for additional clarity, showing a 45 degree turn in a clockwise direction. 
           [0039]    e.  FIG. 5  is a perspective view of the vehicle of  FIG. 1  with parts of the vehicle removed for additional clarity, showing a 45 degree turn in an anti-clockwise direction. 
           [0040]    f.  FIG. 6  is a schematic top view of the vehicle as shown in  FIG. 2  including actuating means according to one embodiment of the invention. 
           [0041]    g.  FIG. 7  is a schematic top view of the vehicle as shown in  FIG. 2  including actuating means according to another embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0042]    With reference to  FIG. 1 , there is shown a vehicle  10  turned in an anti-clockwise orientation. The vehicle  10  comprises a front (i.e. first) chassis  12  and a rear (i.e. second) chassis  14 . The vehicle further comprises a central moving means  19  for moving the front chassis  12  relative to the rear chassis  14 . The moving means  19  is configured so that it can move the front chassis  12  relative to the rear chassis  14  in an anti-clockwise direction about a point in the form of a kingpin  22  on the left side of the vehicle  10 . The front chassis  12  is connected to the rear chassis  14  by the moving means  19 . 
         [0043]      FIG. 2  shows the vehicle  10  turned in a clockwise orientation. The moving means  19  is configured so that it can move the front chassis  12  relative to the rear chassis  14  in a clockwise direction about a point in the form of a kingpin  20  on the right side of the vehicle  10 . The front chassis  12  comprises an axle  30 . Two wheels  32 ,  34  are attached to the axle  30 . The rear chassis  14  comprises an axle  40 . Two wheels  42 ,  44  are attached to the axle  40 . 
         [0044]    With reference to  FIG. 3 , the moving means  19  of the vehicle  10  comprises an upper (i.e. first) connecting member  16  and a lower (i.e. second) connecting member  18  for connecting the front chassis  12  to the rear chassis  14 . The upper connecting member  16  is rotatably connected to the front chassis  12  on a right side thereof by a kingpin  20  and is also rotatably connected to the rear chassis  14  on a left side thereof by a kingpin  22 . In particular, the upper connecting member  16  is rotatably connected to a U-shaped bracket  50  on the front chassis  12  on a right side thereof and to a U-shaped bracket  52  on the rear chassis  14  on a left side thereof. The lower connecting member  18  is rotatably connected to the front chassis  12  on a left side thereof by a kingpin ( 24 ) and is also rotatably connected to the rear chassis  14  on a right side thereof by a kingpin  26  (not shown, best seen in  FIG. 1 ). In particular, the lower connecting member  18  is rotatably connected to a U-shaped bracket  54  on the front chassis  12  on a left side thereof and to a U-shaped bracket  56  on the rear chassis  14  on a right side thereof. The brackets  50 ,  52  are adapted to provide support to the upper connecting member  16 . The brackets  54 ,  56  are adapted to provide support to the lower connecting member  18 . Bearings  21 , such as tapered roller bearings, are used in the connection between the connecting members  16 ,  18  and the kingpins  20 ,  22 ,  24 ,  26  to assist the rotational movement of the connecting members  16 ,  18  about the kingpins  20 ,  22 ,  24 ,  26 . 
         [0045]    With reference to  FIG. 4 , the vehicle  10  is shown with the rear chassis removed to provide a better view of the connecting members  16 ,  18 . The front chassis  12  is orientated at 45° in a clockwise direction relative to the rear chassis  14  (not shown, best seen in  FIG. 2 ). In this orientation, the kingpins  20 ,  26  are substantially close or aligned (in a vertical direction). The upper connecting member  16  is substantially aligned with bracket  52  (not shown in  FIG. 4 ; best seen in  FIG. 3 ) and the lower connecting member  18  is substantially aligned with bracket  54 . 
         [0046]    With reference to  FIG. 5 , the vehicle  10  is shown with the rear chassis removed to provide a better view of the connecting members  16 ,  18 . The front chassis  12  is orientated at 45° in an anti-clockwise direction relative to the rear chassis  14  (not shown in  FIG. 5 ; best seen in  FIG. 1 ). In this orientation, the kingpins  22 ,  24  are substantially close or aligned (in a vertical direction). Also in this orientation, the upper connecting member  16  is substantially aligned with bracket  50  and the lower connecting member  18  is substantially aligned with bracket  56  (not shown in  FIG. 5 ; best seen in  FIG. 3 ). 
         [0047]    In use, the moving means  19  (as seen in  FIG. 1 ) typically comprises actuator means (not shown) to move the front chassis  12  relative to the rear chassis  14 . 
         [0048]    When the vehicle  10  turns from a straight position (not shown) to the left (as seen in  FIGS. 1 ,  3 ,  5 ), the upper connecting member  16  (as seen in  FIG. 3 ) moves relative to the rear chassis  14  about the kingpin  22  and remains substantially motionless relative to the front chassis  12 . In addition, the lower connecting member  18  moves relative to the front chassis  12  about the kingpin  24  and remains substantially motionless relative to the rear chassis  14 . The upper connecting member  16  is substantially parallel to the bracket  50  on the front chassis  12  and the lower connecting member  18  is substantially parallel to the bracket  56  on the rear chassis  14 . Kingpin  24  and kingpin  22  are aligned in a vertical orientation or close to alignment. 
         [0049]    When the vehicle  10  turns from a straight position (not shown) to the right (as seen in  FIGS. 2 ,  4 ), the upper connecting member  16  (as seen in  FIG. 4 ) moves relative to the front chassis  12  about the kingpin  20  and remains substantially motionless relative to the rear chassis  14  (as seen in  FIG. 2 ). In addition, the lower connecting member  18  (as seen in  FIG. 4 ) moves relative to the rear chassis  14  (as seen in  FIG. 2 ) about the kingpin  26  (as seen in  FIG. 4 ) and remains substantially motionless relative to the front chassis  12 . The upper connecting member  16  is substantially parallel to the bracket  52  (as seen in  FIG. 2 ) on the rear chassis  14  and the lower connecting member  18  (as seen in  FIG. 4 ) is substantially parallel to the bracket  54  on the front chassis  12 . Kingpin  20  and kingpin  26  are aligned in a vertical orientation or close to alignment. 
         [0050]    As shown in  FIG. 6 , the vehicle  10  includes hydraulic rams  23   a ,  23   b  as actuating means for assisting the movement between the front and rear chassis  12 ,  14 . A first hydraulic ram  23   a  is pivotally connected between the front chassis  12  and the upper connecting member  16 . A second hydraulic ram  23   b  is pivotally connected between the rear chassis  14  and the lower connecting member  18 . 
         [0051]    To move the vehicle  10  in the clockwise direction as shown in  FIG. 6 , the first hydraulic ram  23   a  is extended and the second hydraulic ram  23   b  is retracted. To move the vehicle  10  in an anti-clockwise direction (see  FIG. 1 ), the first hydraulic ram  23   a  is retracted, and the second hydraulic ram  23   h  is extended. 
         [0052]    In an alternative embodiment as shown in  FIG. 7 , first and second hydraulic rams  27   a ,  27   b  are pivotally connected between the front chassis  12  and the rear chassis  14 . To move the vehicle  10  in the clockwise direction as shown in  FIG. 7 , the first hydraulic ram  27   a  is extended and the second hydraulic ram  27   b  is retracted. To move the vehicle  10  in an anti-clockwise direction (see  FIG. 1 ), the first hydraulic ram  27   a  is retracted and the second hydraulic ram  27   b  is extended. 
         [0053]    In practice, the vehicle in the drawings may also incorporate a number of other components which have not been shown. For example, the vehicle may have a body and “running gear,” such as engine, transmission, driveshaft, differential, suspension and/or the like. 
         [0054]    In another embodiment the vertical placement of the connecting members could be interchanged. 
         [0055]    In a further embodiment, to increase the maneuverability of the vehicle  10 , two sets of moving means  19  may be connected side by side with one another in a cascading arrangement. In this embodiment, the total turning angle between the front and rear chassis  12 ,  14  would be the sum of the turning angle for each moving means  19 . Alternatively, the connection members  16 ,  18  may be significantly longer than the width of the front and rear chassis  12 ,  14  such that an end portion of each connection member  16 ,  18  is connected to an intermediate portion of a side rail disposed on either side of the rear chassis  14 . Such arrangements may be particularly suitable for embodiments in which the front chassis  12  forms part of a motorized vehicle such as a car, and the rear chassis  14  forms part of a trailer. 
         [0056]    The foregoing embodiments are illustrative only of the principles of the invention, and various modifications and changes will readily occur to those skilled in the art. The invention is capable of being practiced and carried out in various ways and in other embodiments. It is also to be understood that the terminology employed herein is for the purpose of description and should not be regarded as limiting. 
         [0057]    In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers unless the context of use indicates otherwise. 
         [0058]    Reference throughout this specification to “one embodiment”, or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. 
         [0059]    The invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described, since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims.