Abstract:
An apparatus and method for maneuvering a trailer having jockey wheel assembly comprising a ground engaging wheel ( 33 ) rotatably mounted on an axle ( 34 ). The apparatus comprising a link member ( 20 ) which is adapted to be pivotally mounted on the jockey wheel assembly adjacent the axle ( 34 ) and a lever assembly ( 10 ) removably securable to said link ( 20 ) and adapted to engage a peripheral surface ( 39 ) of said wheel ( 33 ), whereby movement of said lever ( 10 ) rotates said wheel ( 33 ).

Description:
RELATED APPLICATION 
   This application claims priority to Australian Application No. 2005902847, filed Jun. 2, 2005, the content of which is incorporated herein by reference in its entirety. 
   FIELD OF THE INVENTION 
   The present invention relates to an alignment aid for the manual alignment of the towing hitch of a trailer, caravan, boat trailer, horse float or the like with the tow-ball of a vehicle. In particular although not exclusively the present invention relates to a trailer alignment apparatus suited to a jockey wheel assembly which temporarily supports the towing hitch of the trailer. 
   BACKGROUND ART 
   Typically trailers, caravans, boat trailers, horse floats and the like are provided with a jockey or manoeuvring wheel assembly. The wheel assembly is provided to facilitate movement of the trailer over relatively short distances. The wheel assembly typically includes a raising and lowering mechanism for both levelling of the trailer, and the engagement of and/or removal of the towing hitch from the tow-ball. 
   Manually manoeuvring of the trailer via the jockey wheel is relatively simple when the trailer is carrying a light load. However in instances where the trailer is carrying a large load, manual manoeuvring the trailer can be exceedingly difficult. In such situations the trailer may escape the control of a person manoeuvring the trailer and start to freewheel. This freewheeling can result in the trailer colliding into the towing vehicle, or worse still running down the person manoeuvring the trailer. Accordingly, a number of jockey wheel manufacturers have implemented several arrangements in order to aid manoeuvring and to reduce the risk of freewheeling. 
   One such arrangement is disclosed in WO 2004037567 entitled ‘Jockey Wheel Assembly’, which describes a jockey wheel assembly having a drive system including a crank coupled to a rotatable shaft which is inturn coupled to the wheel hub. Rotation of the crank causes rotation of the shaft, this rotation then being translated into linear movement by the wheel, in a forward or reverse direction depending on the direction of rotation of the crank. The assembly is also provided with a tiller which enables the user to control the direction the wheel is facing and thus control the direction of movement of the trailer. The problem with such an arrangement is that it utilises a number of gears and these gears under the strain of moving such large loads are prone to wear, sheering and slippage, which can lead to a momentarily loss of control over the trailer. This momentary loss of control may be all that is required to cause the trailer to freewheel. 
   Another example of such a jockey wheel assembly is disclosed in AU 2002100165 to Ark Engineering Pty Ltd entitled ‘Jockey Wheel’. The assembly includes a frame mountable on a trailer, a wheel frame and a lever arm. The lever includes a ratchet arm which mates with a corresponding pawl mounted on the frame. The pawls being operable upon pivotal movement of the lever to selectively move or restrain rotation of the wheel in the frame. Again such an arrangement utilises a complex mechanical arrangement which is prone wear to shearing and slippage. 
   Furthermore in both the above arrangements the tyre of the jockey wheel is prone to slip on the wheel hub when the hub is mechanically driven. Such a slippage again can lead to the trailer freewheeling. If the tyre is a pneumatic tyre this slippage can tear out the valve stem leading to deflation of the tyre requiring the replacement of the stem or entire inner tube. 
   Clearly it would be advantageous to provide an alignment apparatus which substantially ameliorates one or more of the aforementioned problems and that is relatively simple to manufacture and use. 
   SUMMARY OF THE INVENTION 
   Accordingly in one aspect of the invention there is provided an apparatus for manoeuvring a trailer having a jockey wheel assembly comprising a ground engaging wheel rotatably mounted on an axle said apparatus comprising:
         a lever assembly adapted to engage the peripheral surface of said wheel, whereby movement of said lever thereby rotates said wheel.       

   In another aspect of the invention there is provided an apparatus for manoeuvring a trailer having a jockey wheel assembly a ground engaging wheel rotatably mounted on an axle, said apparatus comprising:
         a link member pivotally mounted on the jockey wheel assembly adjacent the axle; and   a lever assembly removably securable to said link and adapted to engage a peripheral surface of said wheel, whereby movement of said lever rotates said wheel.       

   In a further aspect of the present invention there is provided a method of manoeuvring a trailer having a jockey wheel assembly comprising a ground engaging wheel rotatably mounted on an axle, said method comprising the steps of:
         positioning a lever assembly on a peripheral surface of said wheel;   applying a force to said lever assembly whereby said lever assembly grips the peripheral surface of said wheel thereby causing rotation of said wheel.       

   In another aspect of the invention there is provided a method of manoeuvring a trailer having a jockey wheel assembly comprising a ground engaging wheel rotatably mounted on an axle, said method comprising the steps of:
         pivotally mounting a link on the wheel assembly adjacent the axle;   coupling a lever assembly to said link, such that said lever assembly engages a peripheral surface of said wheel; and   applying a force to said lever assembly, so as to cause said lever to rotate said wheel.       

   In a further aspect of the present invention there is provided an alignment apparatus for manoeuvring a trailer having jockey wheel assembly comprising a ground engaging wheel rotatably mounted on a hollow axle, said apparatus comprising:
         a link member coupled to a lever assembly adapted to engage a peripheral surface of said wheel, said link member adapted for insertion into said hollow axle to thereby pivotally mount the link member and lever assembly on the jockey wheel assembly; and   whereby, upon insertion of the link member into said hollow axle, lateral movement of the lever assembly directs the wheel on a desired direction of travel and, upon the lever assembly engaging said wheel, rotation of the lever about the pivotal mount acts to rotate the wheel for manoeuvring the trailer in the desired direction of travel.       

   Preferably the lever assembly includes a handle and a wheel engagement portion disposed at one end of the handle. The lever assembly may be manufactured from high grade carbon steel, or other such suitable material capable of withstanding the shear forces generated during movement of a heavily laden trailer or the like. Suitably the handle has a plurality of apertures disposed at a predetermined distance from the pad. 
   The wheel engagement portion may be in the form of a pad. The pad may be any suitable closed shape such as a square, rectangle, hexagon, pentagon, triangle or circle. Most preferably the pad is substantially circular in shape. Suitably the pad may be coated with a material having a relatively high co-efficient of friction such as vulcanised rubber or the like. The pad may be provided with a formation, such as series of grooves that match the shape of the peripheral surface wheel to further increase the frictional engagement therebetween. 
   Alternatively the wheel engagement portion may take the form of a tooth or the like wherein said tooth is shaped for complementary engagement with the peripheral surface of the wheel. Suitably the peripheral surface of the wheel is in the form of a treaded tyre. 
   Suitably the link member is pivotally mounted on the outside of the wheel assembly, or on the inside wheel assembly between the wheel mount and the wheel by any suitable fastening means such as a bolt or cotter pin. Preferably the link is mounted adjacent the axle. Most preferably the link is mounted on the axle of the wheel assembly. 
   Preferably the link is a single elongate member. Alternatively the link may be formed from a plurality of interlinked members. The link may include one or more mounting plates secured the end of the link. In the case where the axle is hollow the link member is preferably in the form of a rigid C-shaped bar wherein one arm of the bar is coupled to the lever assembly and the remaining arm is adapted for insertion into the hollow axle. 
   Preferably the link extends about a portion of the wheel forming a space therebetween into which the lever can be inserted. The link may have a pin slideably mounted thereon, said pin being inserted into one of the plurality of apertures provided in the handle, to thereby secure the lever assembly to the link in a removable manner. 
   Alternatively the link may extend from the frame adjacent the wheel, the lever then being positioned on the wheel and adjacent the link. The link may also include a plurality of apertures through which a pin may be inserted, the pin then being passed through a corresponding aperture provided on the handle of the lever assembly, to thereby secure the lever assembly to the link in a removable manner. 
   The apparatus may further include a braking assembly mounted on the frame that is selectively engagable with the peripheral surface wheel. Suitably the braking assembly includes a brace and a plate. The plate may include a tail for engagement with the brace and a tip for engagement with the peripheral surface wheel. Preferably the plate is positioned within the wheel mount. The brace may include a lever coupled to a pin. Suitably the pin is U-shaped with one arm of said U passing through the wheel mount. 

   
     BRIEF DETAILS OF THE DRAWINGS 
     In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings, which illustrate preferred embodiments of the invention, and wherein: 
       FIG. 1  is a schematic diagram showing one possible arrangement of a lever and a pin of a trailer alignment apparatus according to an embodiment of the present invention; 
       FIG. 2  is a schematic diagram depicting the trailer alignment apparatus according to one embodiment of the present invention in position on a jockey wheel assembly; 
       FIG. 3  is a schematic diagram depicting the trailer alignment apparatus of  FIG. 2  during the driving stroke; 
       FIG. 4  is a schematic diagram depicting the trailer alignment apparatus of  FIGS. 2 and 3  during the return stroke upon completion of the driving stroke; 
       FIG. 5A  is a schematic diagram depicting the alignment aid mounted on a jockey wheel assembly according to a further embodiment of the present invention; 
       FIGS. 5B to 5G  depict the stages in operation of another arrangement of a braking mechanism for use with the trailer alignment apparatus of the present invention; 
       FIG. 6  is a schematic diagram depicting a still further embodiment the trailer alignment apparatus mounted on a jockey wheel assembly according to the present invention; 
       FIG. 7A  is a perspective view of a link member according to one embodiment of the present invention; 
       FIG. 7B  is a schematic view of a link member according to a further embodiment of the present invention; 
       FIG. 7C  is a perspective view of a link member according to a still further embodiment of the present invention; and 
       FIGS. 8A to 8C  illustrate stages in operation of a further embodiment of the trailer alignment apparatus of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to  FIG. 1  there is illustrated an embodiment of the lever  10  for an alignment apparatus of the present invention. The lever includes handle  11  and pad  12  and a plurality of apertures  13   a - d  disposed along the handle at varying locations. Apertures  13   a - d  are provided so as to allow a pin  14  to be inserted therethrough. Pin  14  is adapted to pass through an aperture  21  in link  20  (see  FIGS. 2 and 7A ) thereby securing the lever  10  in a removable manner to link  20 . The amount of purchase on the tyre  39  of the wheel  33  imparted by lever  10  is proportional to the distance of the pad to the aperture  13   a - d  at which the pin  14  is inserted. For example the maximum available purchase is provided when the pin  14  is inserted into the furthermost aperture  13   a.    
   Pad  12  may be any suitable shape such as a square, rectangular, hexagonal, pentagonal or circular. However the pad  12  is most preferably substantially circular in shape. Providing a circularly shaped pad allows the lever  10  to be utilised through a wider range of angles θ to the vertical (see  FIG. 6 ). This is particularly the case as discussed below in relation to  FIG. 6  when the link is in the form of a tensile cable  23 . In addition the pad may be provided with a frictional coating on its engagement face in order to increase the amount friction between the pad  12  and wheel  33  when engaged, thereby further increasing the amount of purchase on the wheel  33  during the lever&#39;s movement stroke. Alternatively the face of the pad  12  may be provided with a series of grooves that match or at least co-operate with the peripheral surface of the wheel  33 . Upon engagement the pad with the wheel  33  the pad  12  is inserted within the corresponding groove thereby further increasing the amount of purchase on the wheel  33  during the movement stroke. 
     FIG. 2  depicts the trailer alignment apparatus of one embodiment of the present invention positioned on a jockey wheel assembly  30  which is attached to the trailer&#39;s A frame (not shown). The wheel assembly  30  includes wheel  33  having a treaded tyre  39  supported on axle  34  within a wheel mount  32  and an extendable support  31 . Link  20  is pivotally mounted at point  22  on wheel mount  32  adjacent the axle  34 . In use lever  10  is positioned adjacent the link  20  with pad  12  engaging the periphery of wheel  33 , namely the treaded surface of tyre  39 . Pin  14  is then inserted through aperture  21  in link  20  into one of the corresponding apertures  13   a - d  in handle  11  (in this instance aperture  13   b ). 
   In order to align the towing hitch of the trailer with the tow ball the wheel  33  is inched forward by drawing down handle  11  as shown in  FIG. 3 . As handle  11  is drawn down by a user through a driving stroke in the direction of arrow  35 , pad  12  grips the tyre  39  of wheel  33  thereby forcing it against the hub. Link  20  in turn pivots with the movement of lever  10  thereby causing pad  12  to rotate wheel  33  in the desired direction  36  to draw the trailer linearly in this case the forward direction. 
   Upon the lever  10  reaching the apex of the driving stroke (i.e. pad  12  is brought into contact with the ground), the pressure is released form handle  11  and pad  12  is removed from the tyre see  FIG. 4 . The lever  10  and link  20  are then returned to their positions prior to the commencement of the downward stroke  35  as illustrated in the dashed outline. The lever  10  may then be engaged with the wheel  33  ready for the next downward driving stroke  35 . This process is then repeated until the towing hitch is positioned above or at least adjacent to the tow ball. 
   With the arrangement of the alignment apparatus as discussed with reference to  FIG. 1 to 4 , lever  10  may also be used to brake the wheel  33 . By applying a sufficient downward force on handle  11 , pad  12  is wedged against the tyre  39  forcing it against the hub preventing movement of wheel  33 . Applying this type of braking to the wheel  33  steadies the trailer and reduces unwanted movement until the wheels of the trailer can be chocked. Once the chocks are in position the force may be released from handle  11  thereby disengaging pad  12  from wheel  33 . The lever  10  and link  20  may then be returned to their initial position ready for the next downward stroke  35  as discussed above. 
   In a further embodiment the jockey wheel assembly may alternatively be fitted with braking mechanism  37  as shown in  FIG. 5A . The braking mechanism is engaged with the wheel  33  prior to removal of pad  12 . Upon re-engagement of the pad  12  with wheel  33  at the top of the movement stroke (shown in dashed outline) brake  37  is released, and handle  11  drawn downward to impart movement of wheel  33  in the desired direction  36 . 
     FIGS. 5B to 5F  illustrate another possible arrangement of the braking mechanism for use with the alignment aid of the present invention. In this instance the braking mechanism includes a brace  40  and plate  38  which in the present case is positioned within the wheel mount  32 . Brace  40  is includes a lever  41  which is coupled U-shaped pin  42 . The plate  38  as shown includes a tail  45  for engagement with the brace, a tip  44  for engagement with the surface of the tyre  29 . The tip being connected to the main body of the plate  38  via neck  43 . 
   In  FIGS. 5B and 5C  the braking mechanism is shown in the locked position with tail  45  positioned over both arms of the u-shaped pin  42 . In this position the main body of the plate  38  is free to rest upon the tyre  29  with the tip being elevated above the tyre  29  see  FIG. 5C . In the locked position the breaking mechanism allows the wheel to move in the forward direction only. Any movement of the wheel in the opposing direction forces the plate  38  back toward the wheel mount  32  forcing tail  45  away from the external arm  42   a  of pin  42  see  FIG. 5B . This causes the neck  43  to engage the wheel mount  32  forcing tip  44  to bite down onto the surface of the tyre  29  thereby braking the wheel  33 . 
     FIGS. 5D to 5F  illustrate the various stages of releasing the brake mechanism to enable free motion of the wheel  33 . In the initial stage of release the lever  41  of brace  40  is drawn upward forcing the external arm  42   a  of pin  42  downward and away from plate  38  ( FIG. 5E ). Plate  38  may then be manually drawn forward so that the tail  45  engages the internal arm  42   b  (not pictured) of the pin  42 . Lever  41  is then pushed downward to its lowest most extent positioning the external arm  42   a  against the wheel mount  32  and drawing the internal arm  42   b  of pin  42  into engagement with tail  45  thereby wedging the plate against the stirrup of the wheel mount  32 . This wedging action inturn raise the remainder of the plate including the neck  43  and tip  44  clear of the surface of the tyre  29  allowing wheel  33  to run free (see  FIGS. 5G and 5F ). 
   With reference to  FIG. 6  there is shown an alternative embodiment of link  20  and the manner in which it is pivotally mounted on the jockey wheel assembly  30 . In this instance link  20  is in the form of a tensile cable  23  coupled to mounting plates  22 . The plates  22  are mounted on the axle  34  between the wheel mount  32  and wheel  33  such that cable  23  extends between opposite ends of the axle  34  and is positioned about the wheel  33  creating a space  38  therebetween. Pin  14  is slidably mounted on the cable  23 . In operation lever  10  is positioned in the space  38  between the cable  23  and the wheel  33 . Pin  14  is then inserted into the desired aperture  13   a - d  thereby removably securing lever  10  to link  20 . Lever  10  may then be engaged with the wheel  33  in the manner discussed above in order to move wheel  33  in the desired direction. With this arrangement the position of the lever can be varied from vertical through a range of angles θ as illustrated by the lever positions shown in broken lines. Accordingly the user need not be directly in front of the jockey wheel assembly in order to use the lever  10  but can be to one side of the jockey wheel without a losing purchase on wheel  33 . 
     FIGS. 7A to 7C  illustrate in greater detail a number of possible configurations of the link  20 .  FIG. 7A  depicts a rigid link  20  in the form of a single bar  23  not unlike that discussed above in relation to  FIGS. 2 to 5 . Bar  23  includes a number of apertures  21   a - c  through which pin  14  can be inserted, this enables the position at which lever  10  is secured to the bar  23  to be selectively varied. Bar  23  also includes a mounting aperture  22  via which the link  20  is pivotally mounted to the wheel mount  32  or on axle  34  and is held in position by a suitable fastening means such as a bolt, cotter pin or CER-clip. 
     FIG. 7B  shows the link  20  in this instance in the form of rigid U or C shaped bracket  23 , upon which pin  14  is slidably mounted. The bracket  23  includes mounting apertures  22  via which the link  20  is pivotally mounted to the wheel mount  32  or on the axle  34  by a suitable fastening means. 
     FIG. 7C  depicts a flexible link  20  in the form of a tensile cable  23 . Cable  23  is attached to a pair of mounting plates  22  having apertures  24  via which the link  20  is pivotally mounted on the axle  34  of wheel  33 . The cable  23  may be attached to the mounting plates  22  via any suitable means e.g. the ends may be swagged to the plates. An alternative arrangement for mounting the cable  23  to the axle  34  is the simply for a loop at end these loops are then secured back to the main cable  23  by a swagged connector. 
     FIGS. 8A to 8C  illustrate a further embodiment of the alignment apparatus of the present invention. In this instance the link  20  is in the form of a rigid C shaped bar with end  20   a  coupled to the lever  10  at a predetermined distance from the wheel engagement portion  12 . End  20   b  of the link  20  is adapted to be pivotally mounted within hollow axle  34 . Lever  10  is secured to link in such a manner so as to enable the lever  10  to be pivoted about end  20   a . The wheel engagement portion  12  in this particular case includes at least one tooth  12   a , said tooth being shaped for complementary engagement with the peripheral surface  39  of the wheel  33 . As shown in  FIG. 8   a  link  20  and lever  10  are designed to be removable from the jockey wheel assembly. As lever  10  can be pivoted about end  20   a  the link  20  may be conveniently fold against the lever  10  for easy of storage. 
     FIG. 8B  shows the link  20  and lever  10  mounted in situ on the jockey wheel assembly with end  20   b  being mounted within hollow axle  34 . Applying a driving force  35  in the direction of arrow  35  cases the tooth  12   a  of wheel engagement portion  12  to grip the tyre  39  rotating the wheel in the direction of arrow  36 . 
     FIG. 8C  shows the reverse angle of the apparatus as shown in  FIG. 8B  by applying a lateral force in either of the directions indicated by arrow  82  directs the wheel in a desired direction of travel. Once the wheel is positioned in the desired direction of travel a driving force is applied in the direction of arrow  35  cases the tooth  12   a  of wheel engagement portion  12  to grip the tyre  39  to rotate the wheel to thereby move the trailer in the desired direction of travel. At the base of the drive stroke a force is applied in the direction of arrow  81  causing lever  10  to pivot about end  20   a  of link  20  thereby releasing tooth  12   a  from tyre  39 . Upon release a user may then change the direction of the tyre if required or simply return the lever to the top of the drive stroke if further movement in the desired direction is required. 
   It is to be understood that the above embodiments have been provided only by way of exemplification of this invention, and that further modifications and improvements thereto, as would be apparent to persons skilled in the relevant art, are deemed to fall within the broad scope and ambit of the present invention described herein.