AU2011201990B2 - Coupling for a support mechanism - Google Patents

Abstract

The present invention relates to a coupling for attaching a support mechanism to a vehicle. The invention has particular application in situations where the support mechanism is a jockey wheel and the vehicle is a trailer. The coupling 5 300 includes a first member 304 arranged for connection to the support mechanism (jockey wheel 400) and a second member 306 arranged for connection to the vehicle (trailer frame 500). The connection between the first member 304 and the second member 306 is arranged to enable translating movement of the first member 304 relative to the second member 306 between 10 an upper position and a lower position. In the upper position, the first member 304 is substantially prevented from pivoting relative to the second member 306 and in the lower position the first member 304 is free to pivot relative to the second member 306. ---- 6/6 Figure Sc 326 : o 5 304 -- 500 306 ----- - -- --- - - - - -- - -. 0 s 's - 404 Figure 5d

Description

P/00/011 Regulation 3.2 -1 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: COUPLING FOR A SUPPORT MECHANISM Applicant: MOVE YOURSELF TRAILER HIRE PTY LTD The following statement is a full description of this invention, including the best method of performing it known to me: -2 COUPLING FOR A SUPPORT MECHANISM FIELD OF THE INVENTION The present invention relates to a coupling for a support mechanism for a 5 vehicle. In a typical application the vehicle is a towed vehicle and the coupling is for a jockey wheel support mechanism. The jockey wheel may be arranged to support a beam or frame of the towed vehicle at a desired height relative to a supporting surface. 10 BACKGROUND TO THE INVENTION Towed vehicles such as trailers, caravans, horse floats and the like often include a support mechanism, such as a jockey wheel, attached to a front end of the towed vehicle's chassis near a hitching element. The hitching element may include, for example, a socket which is adapted for receiving a tow ball 15 fixed to a tow bar of a tow vehicle, such as a car or truck. When the towed vehicle is not in use, the support mechanism may be deployed to support the front-end of the towed vehicle so that the front-end rests on the support mechanism. In addition, some support mechanisms 20 include a ground engaging wheel which allows the towed vehicle to be more readily manoeuvred or steered. This is particularly useful when trying to hitch the towed vehicle to the tow ball of a tow vehicle. A a One conventional support mechanism which permits the towed vehicle to be 25 manoeuvred includes an adjustable jockey wheel mechanism. An adjustable jockey wheel mechanism (hereafter referred to as a "jockey wheel") typically includes an outer tube, a shaft located within the outer tube, a wheel connected to the lower end of the shaft and a crank handle. The crank handle, shaft and outer tube are arranged so that rotation of the crank handle in one 30 direction retracts the shaft into the outer tube and rotation of the crank handle in the other direction extends the shaft out of the outer tube. In this manner it will be appreciated that rotation of the crank handle by a user serves to either -3 raise or lower the wheel to bring it in and out of contact with the ground and thus change the height of the wheel relative to the chassis. The jockey wheel is typically connected to the chassis of the towed vehicle 5 (e.g. a trailer) using a coupling so that the shaft is located generally vertically. When the jockey wheel is not in use, for example when the trailer is under tow, and if the ground engaging wheel is not lifted away from the ground a sufficient distance, the jockey wheel is susceptible to damage. Damage typically occurs when the jockey wheel, more specifically the ground engaging wheel or the 10 shaft, is impacted or strikes an object such as the ground, a gutter or a part of a road surface. The impact force typically damages the jockey wheel so that the wheel can no longer be raised or lowered. In some instances the impact force may actually damage the coupling that connects the jockey wheel to the chassis. To mitigate this, some jockey wheels are arranged to be removable 15 from the trailer for storage when not in use. Unfortunately, removing the jockey wheel from the trailer may be difficult or simply inconvenient to some users. This is particularly the case when the user is not familiar with the proper use of jockey wheels, as is often the case with a user who infrequently hires a trailer from a hire service. 20 Figure 1 shows another coupling 100 for a support mechanism in the form of a jockey wheel 102. The coupling 100 is arranged to mount the jockey wheel 102 to the chassis 104 of a trailer (not shown). The coupling 100 is mounted to the chassis 104 using a coupling 100 that has a pivot joint 106 (Figure 2). 25 The pivot joint 106 permits the jockey wheel 102 to be rotated or swivelled between a stowed position (Figure 1) and a deployed position (Figure 2). As shown in Figure 1, in the stowed position the jockey wheel 102 is held so that the ground engaging wheel 108 does not extend substantially lower than the chassis 104 and is thus less susceptible to damage during towing due to 30 inadvertent impact. On the other hand, when the jockey wheel 102 is in the deployed position (Figure 2) it is locked in a generally upright configuration by a locking pin 110 or the like. Even though the jockey wheel 102 is rotatable to -4 a stowed position, the user is still required to unlock the locking pin 110 and to rotate the jockey wheel 102 to the stowed position. Accordingly, the jockey wheel 102 may still be susceptible to damage if the user neglects to move and lock the jockey wheel 102 in the stowed position or if the user simply uses the 5 crank handle 107 to raise the wheel 108 off the ground to provide some clearance prior to towing the trailer. There is a need for an improved coupling for a support mechanism used with towed vehicles, such as trailers. 10 The above discussion of the background to the invention is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge (in any country) as at the priority date of any of the claims. 15 SUMMARY OF INVENTION According to a first aspect of the present invention there is provided a coupling for attaching a support mechanism to a vehicle, the coupling including a first member arranged for connection to the support mechanism; a second member 20 arranged for connection to the vehicle; a connection between the first member and the second member, the connection arranged to enable translating movement of the first member relative to the second member between an upper position in which the first member is substantially prevented from pivoting relative to the second member and a lower position in which the first 25 member is free to pivot relative to the second member, and wherein the second member includes at least two abutment means arranged so that when the first member is located in the upper position the first member is located between the two abutment means so that the first member is substantially prevented from pivoting relative to the second member. 30 -5 By suitably configuring the first member and the second member, the support mechanism connected to the first member will be rotatable between a stowed (or inoperative) position and a deployed (or operative) position. In accordance with a particularly preferred embodiment of the invention, the support 5 mechanism is a jockey wheel and thus in the deployed (or operative) position of the first member, the jockey wheel adopts a generally upright orientation. In the stowed position the jockey wheel is preferably generally aligned with a supporting frame of the vehicle chassis. 10 It should be understood that the reference to the first member being substantially prevented from pivoting when in the upper position indicates the possibility of some very limited pivotal movement of the first member in the upper position. Such limited pivotal movement may occur in the event that there is a small gap between at least one edge of the first member and the 15 abutment means. The intention however is that when, for example, the support mechanism is a jockey wheel, the shaft of the jockey wheel extends substantially upright and is retained in that position when the first member is in the upper position. 20 The at least one edge for contacting an abutment means preferably includes a section of a side edge of the first member. In this form, when the first member is in the upper position each side edge section is juxtaposed to a respective abutment means of the second member which prevents pivotal movement of the first member in that position. In one embodiment, the first member has a 25 generally square configuration and the one or more side edge sections include portions of the opposite sides edges of the square configuration. However, it is possible that an edge section may include an entire edge, such as an entire top edge. 30 The first member preferably includes one or more support elements projecting outwardly from a surface of the first member and arranged for supporting and/or locating the support mechanism for connection to the first member. In -6 one embodiment each support element includes one or more folds. For example, the support elements may include one or more folded edges of the first member. In another embodiment the support elements may include a web or rib disposed on the surface of the first member. 5 Each support element may include a recess for receiving a part of the support mechanism. When the support mechanism is a jockey wheel, each recess is sized and shaped to receive a portion of an outer tube of the jockey wheel. 10 In one embodiment the first member includes support elements which extend substantially entirely between the opposite side edges of the first member. Preferably, the support elements are configured to position the support mechanism relative to the second member so as to provide a clearance between the support mechanism and the abutments means so that rotation of 15 the first member under certain conditions does not cause the support mechanism to contact the abutment means. The second member preferably includes a plate. The abutment means may be attached to the plate or they may be integrally formed with the plate. 20 It is preferred that the abutment means include a pair of spaced apart projections located to receive an upper portion of the first member during translating movement of the first member from the lower position to the upper position. The projections are preferably shaped to define a receiving channel 25 having a width which progressively narrows from a first width to a second width to provide a guide for directing the first member into the upper position during translating movement of the first member from the lower position to the upper position. Hence, each projection may include a guiding element, such as an edge, for guiding the first member into the second position during translating 30 movement from the lower position to the upper position.

-7 The connection between the first member and the second member is preferably in the form of a pivot joint adapted to connect the first member and second member and to permit translating movement of the first member relative to the second member. Preferably the translating movement is a 5 sliding movement with the first member sliding along the second member between an upper position and a lower position and vice versa. In the upper position the one or more abutment means are located to substantially prevent rotation of the first member and in the lower position the pivot joint supports the first member for rotation. 10 Preferably the pivot joint connects the first member and the second member in a connection arrangement which forms cooperating planar surfaces such that the sliding movement involves the cooperating planar surfaces. More specifically, it is preferred that the pivot joint positions a planar surface of the 15 first member in sliding contact with a planar surface of the second member, so that the surfaces are thus cooperating planar surfaces in which the surface of the first member is in a coplanar relationship with the surface of the second member and which allows the first member to slidably move along the second member between the lower position and the upper position. 20 In one embodiment, the pivot joint includes a slot and pin arrangement. The pin includes a shank that is arranged for translation along the length of the slot and to rotate there within. In accordance with a preferred embodiment, the pin is attached to or extends from the first member and the second member 25 incorporates the slot. The slot preferably extends from an upper portion of the second member towards a lower portion of the second member to define an axis of translation or motion. It is preferred that the slot is disposed symmetrically of, and extends lengthwise along, a central axis of the second member. 30 -8 In accordance with an embodiment of the invention the second member may include two slots that are aligned so as to both receive respective portions of the shank of the pin. 5 It is anticipated that embodiments of the present invention will be suitable for use with different types of support mechanisms, such as a support mechanism which includes a fixed length support or a variable length support. An example of a fixed length support is a simple post or stand. However, it is envisaged that the present invention will be particularly suited for use with support 10 mechanisms having a variable length support like that of a conventional jockey wheel or jack. Another aspect of the present invention provides a support for a vehicle, the support including: a support mechanism; and a coupling including a first 15 member arranged for connection to the support mechanism; a second member arranged for connection to the vehicle; a connection between the first member and the second member, the connection arranged to enable translating movement of the first member relative to the second member between an upper position in which the first member is substantially prevented from 20 pivoting relative to the second member and a lower position in which the first member is free to pivot relative to the second member, and wherein the second member includes at least two abutment means arranged so that when the first member is located in the upper position the first member is located between the two abutment means so that the first member is prevented from 25 pivoting relative to the second member. An embodiment of the present invention may be suitable for use with a trailer, such as a boat trailer, box trailer or a caravan. Preferably the second member is located on a beam of the vehicle chassis. In use, the support mechanism 30 may be actuated to raise the beam to, or maintain the beam at, a required height relative to the ground. For example, in an embodiment in which the support mechanism is used for a trailer or caravan, the support mechanism -9 may aid positioning of a hitch cup at or near a height for lowering onto a tow ball of a towing vehicle. When hitched, the first member may be rotated to position the support mechanism in the stowed position. Hence an embodiment of the present invention provides a support mechanism which is rotatable 5 between a first position, which is the deployed position, and a second position which is the stowed position. In the stowed position the support mechanism is less likely to be damaged by inadvertent impact. Furthermore, when the first member is in the lower position with the pin in contact with a lower end of the slot, the first member and hence the attached support mechanism is free to 10 rotate. Hence, if the support mechanism is inadvertently impacted or inadvertently strikes an object it is able to rotate (i.e. pivot) upwardly towards the chassis of the vehicle to hopefully avoid or at least minimise impact damage. 15 Before turning to a general description of the invention, clarification needs to be provided for some of the terms that have been used. It will be noted that the terms "upper" and "lower" are used. These terms are used with reference to an in situ coupling. Thus a reference to a member or part being an "upper" member or part (for example) will be a reference to a member or part that is 20 normally above (but not necessarily immediately above) another member or part in situ. Other terms that may additionally require clarification will be further explained below. BRIEF DESCRIPTION OF THE DRAWINGS 25 The following detailed description of a preferred embodiment of the invention will be better understood when read in conjunction with the appended drawings. The present invention is illustrated by way of example and not limited by the accompanying figures, in which like references indicate similar elements. 30 Figure 1 is a perspective view of a prior art coupling with the support mechanism in a stowed position; -10 Figure 2 shows the support mechanism of Figure 1 in a deployed position; Figure 3 is a perspective view of a coupling according to an embodiment of the present invention with a support mechanism in the form of a jockey wheel; 5 Figure 4 is an exploded perspective view of the coupling of Figure 3; and Figures 5a to 5d are side views of the coupling shown in Figures 3 and 4 during operation of the jockey wheel. 10 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION It should be noted that although the following embodiments will be described with reference to a support mechanism in the form of a jockey wheel it is not 15 essential that the support mechanism adopt such a form. The support mechanism may adopt other forms such as, for example, a jack or a post. It should thus be understood that the present invention is not limited to use with a support mechanism in the form of a jockey wheel. 20 Referring to Figure 3 there is illustrated a coupling 300 in accordance with an embodiment of the present invention for coupling a support mechanism to a towed vehicle (not shown). The support mechanism is a jockey wheel 400. The individual components of the coupling 300 are best illustrated in Figure 4. 25 The coupling 300 includes a first member 304, a second member 306 and a connection, in the form of a pivot joint 308, arranged to connect the first and second members 304, 306 together. The jockey wheel 400 includes an outer tube 402, a shaft 404, a ground engaging wheel 406 and a crank handle 408. As per the previously described prior art jockey wheel, the shaft 404 can be 30 extended from and retracted into the outer tube 402 by selective directional rotation of the crank handle 408.

-11 The first member 304 of the coupling 300 includes two spaced apart supporting portions 318 (Figure 3) arranged in a parallel relationship. In the present case, each supporting portion 318 extends across the width of the first member 304. 5 The supporting portions 318 include folded sections which project from an outwardly facing surface 322 of the first member 304. Each supporting portion 318 includes a recess 324 (Figure 4) which is sized to receive a respective portion of the outer tube 402 of the jockey wheel 400. Referring to Figure 4 it 10 can be seen that in the illustrated embodiment the outer tube 402 is cylindrical and each recess 324 is sized according to the diameter of the respective portion of the outer tube 402. The recesses 324 are positioned and aligned with respect to each other so as to receive the outer tube 402 and to align the shaft 404 of the jockey wheel 400 centrally with respect to the first member 15 304. The outer tube 402 is attached to the supporting portions 318 by welding to thus rigidly connect the jockey wheel 400 to the first member 304. In other embodiments it is possible that the jockey wheel 400 may be attached to the 20 first member 304 using a fastening means such as a clamp (such as a "U clamp"), or suitable fasteners so that the jockey wheel 400 is removable from the first member 304. As shown in Figure 4, the first member 304 includes opposite side edges 326, 25 328 and a back or inwardly facing planar surface 330 (Figure 4) on the rear of the first member 304. A locking pin 332 is located and supported by a pin support arrangement in the first member 304. The locking pin 332 is biased by a biasing means in the form 30 of spring 336. The spring 336 biases the locking pin 332 so that when the locking pin 332 aligns with a locking hole 340 in the second member 306, the spring 336 urges the locking pin 332 into the locking hole 340. The locking pin -12 332 also includes a gripping end 342 for a user to release the locking pin 332 from the locking hole 340 using a pulling action. The role of the locking pin 332 and the locking hole 340 will be described in more detail later. 5 The second member 306 includes a front plate 343 and a rear plate 344. The shape of the front plate 343 is best depicted in Figures 5a to 5d and may be described as adopting a generally inverted "L" shape. This shape has been adopted to ensure that the first member 304 can rotate to the stowed position when first member 304 is in the lower position. The illustrated shape provides 10 the necessary clearances. Other shaped front plates 343 may however be adopted. The front plate 343 and rear plate 344 are spaced apart using supporting webs 345 to provide a gap therebetween in the form of a clearance. However, it is 15 possible that the second member 306 may be manufactured with a single plate. The front plate 343 includes an outwardly facing generally planar surface 347 that extends throughout a top or upper portion and a bottom or lower portion. 20 The front or outwardly facing surface 347 is adapted to cooperate with the back surface 330 of the first member 304 to permit sliding movement of the back surface 330 of the first member 304 along the outwardly facing surface 347 of the second member 306. This movement will be described in more detailed later. 25 Referring again to Figure 4, aligned elongate apertures are formed in the front plate 343 and rear plate 344 of the second member 306. Each elongate aperture is in the form of a slot 362. Each slot 362 includes parallel side walls 364 located symmetrically about a centre line of the second member 306 that 30 extend between an upper rounded end 366 and a lower rounded end 368.

-13 As mentioned previously, the first and second members 304, 306 are connected together by pivot joint 308. The pivot joint 308 includes a pin 372 having a shank 370 that passes through, and thus is contained within, each of the elongate slots 362. 5 The pin 372 includes a head 374 and an end 376. The shank 370 of the pin 372 passes through a hole 378 located at the centre point of the first member 304 so that the shank 370 projects perpendicularly from the back surface 330 of the first member 304. 10 As shown in Figure 3, the underside of the head 374 of the pin 372 rests against the outwardly facing surface 322 of the first member 304 to secure the pin 372 to oppose tension applied to the shank 370. In the embodiment illustrated, the head 374 is welded to the outwardly facing surface 322 to 15 secure the pin 372 to the first member 304. It will of course be appreciated that different pin configurations could be used. For example, another suitable pin may include a thread adjacent to the head 374 for insertion into a correspondingly threaded hole to thereby secure the pin to the first member 304. It will also be appreciated that it is not essential that the pin 372 includes 20 a head, nor that the pin 372 be inserted through a "through hole" in the first member 304, since the pin 372 could just as easily be secured to, for example, the hole 378, or to the back surface 330 of the first member, or to a "blind hole" located on the back surface 330. 25 The shank 370 has a length which is sufficient to allow it to pass through the slots 362 in each of the front and rear plates 343, 344 of the second member 306 and so that the threaded end 376 protrudes from the slot 362 in the rear plate. A retainer 379, for example a lock nut or a washer welded to the pin 372, is used to secure the pin 372 with the second member 306. It is not 30 essential that the pin 372 include a nut since other configurations may be used to secure the pin 372 to the second member 306.

-14 The described arrangement of the pin 372 and slots 362 form a connection that enables the shank 370 of the pin 372 to rotate or pivot, in certain positions to be explained later, about a pivot axis collinear with the central longitudinal axis of the shank 370. Accordingly, the connected first member 304 can rotate 5 similarly. Additionally, the shank 370 of the pin 372 can be translated along the length of the slots 362 between the lower and the upper positions. Abutment means in the form of a pair of projecting portions 352 are located at laterally opposed edges 353 of the second member 306. Each projecting 10 portion 352 projects outwardly relative to the plane of the outwardly facing surface 347 and includes an edge 354 (Figure 3) for providing an abutment surface juxtaposed to a respective side edge 326, 328 of the first member 304 when the first member 304 is located at the second or upper position, It will be appreciated that some embodiments of the present invention need not include 15 projecting portions but may nevertheless include a second member 306 which is adapted to substantially prevent rotation of the first member 304 when the first member 304 is located in the upper position. The projecting portions 352 depend downwardly from a top edge 356 of the 20 second member 306 from the upper portion towards the bottom portion so that a section of each opposite side edges 326, 328 of the first member 304 is able to be juxtaposed with a respective projecting portion 352 throughout some part of the travel of the first member 304 between the lower and upper positions. In the present case, the projecting portions 352 overlap with the opposite side 25 edges 326, 328 of the first member 304 over that part of the travel so as to substantially prevent rotation of the first member 304 over that travel distance. A clearance may be provided between the opposite side edges 326, 328 of the first member and the and the edges 354 of the projecting portions 352 so that 30 the projecting portions 352 allow the first member 304 to move freely between the upper position and the lower position when the shaft 404 is orientated to align with the axis of movement. However, when the first member 304 is - 15 located in the upper position, the edges 354 of the projecting portions 352 will abut with he opposite side edges 326, 328 of the first member 304 if rotation of the first member 304 is attempted. In other words, when the first member 304 is located at the upper position, the projecting portions 352 prevent rotational 5 movement of the first member 304. As depicted, the projecting portions 352 are welded onto the surface 322 and located proximal to a section of the edges 353 located at the top portion of the second member 306. However, in other embodiments the projecting portions 10 352 may be provided by forming the second member 306 from a folded metal plate or machined construction. Furthermore, although in the present embodiment the projecting portions 352 form abutment means located at the side edges of the top portion of the second member 306 it is possible that other configurations may be suitable. For example, another suitable projecting 15 portion may include a stud, bolt, pin, or boss which is attached or otherwise secured to the top portion to provide the abutment means. As shown in Figure 5c and Figure 5d, the projecting portions 352 are shaped to guide the first member 304 into the upper position during movement of the 20 first member 304 along the second member 306 into and out of the upper position. In other words, the projecting portions 352 are shaped to progressively restrict the extent of permissible rotational movement of the first member 304 as the first member 304 moves into the upper position. 25 In accordance with the illustrated embodiment, the outwardly facing surface 347 of the second member 306 is retained generally in contact with the back surface 330 of the first member 304 in a cooperating relationship which permits the first member 304 to slide along the second member 306 between the lower position and the upper position. The pivot joint 308 only allows the first 30 member 304 to freely rotate when the first member 304 is located at the lower position. In the lower position the shank 370 of the pin 372 rests against the lower rounded end 368 of each slot 362 and rotational movement is permitted -16 because the first member 304 when rotating does not abut the abutment means (projecting portions 352). When the first member 304 is in the lower position and the wheel 406 of the jockey wheel 400 is off the ground, the weight of the first member 304 and the connected jockey wheel 400 is 5 supported by the second member 306. When the first member 304 is located in the upper position, the upper rounded end 366 of the slot 362 abuts against the shank 370 to prevent further upward movement and rotation of the first member 304 is prevented by contact with the abutment means (projecting portions 352). 10 It is to be noted that the slot 362 and pin 372 may be otherwise configured to allow the first member 304 to slide along the second member 306 into and out of the upper position such that in the lower position the first member 304 is rotatable about the longitudinal axis of the pin, and in the upper position the pin 15 372 and the slot 362 cooperate to prevent rotation of the first member 304. Such an embodiment may alleviate the need to include the projection portions 352. To assist with the explanation of the coupling 300, example operation 20 sequences of the coupling 300 when used with a jockey wheel 400 are set out below. Example 1: Deploying a Jockey Wheel from a Stowed Position Referring to Figures 5a and 5b it can be seen that the jockey wheel 400 has 25 been mounted onto a trailer frame 500 using the coupling 300. The jockey wheel 400 is orientated to a stowed position with the coupling 300 fully supporting the weight of the jockey wheel 400. In this position the locking pin 332 is engaged within the hole 340 (Figure 3) in the second member 306 to prevent rotational movement of the first member 304 (and thus the attached 30 jockey wheel 400). The shank 370 of the pin 372 rests against the lower rounded end 368 of the slot 362.

-17 To deploy the jockey wheel 400 the user first releases the locking pin 332 from the hole 340 by pulling outwardly against the bias of the spring 336. As shown in Figure 5b, upon release of the locking pin 332 the first member 304 is released to rotate about the pivot axis extending collinear with the central 5 longitudinal axis of the shank 370 of the pin 372. The amount of rotation achievable will depend upon the height of the coupling 300 above the ground 504 (Figure 5c) relative to the distance between the pin 372 and the bottom most part of the wheel 406, as determined by the length of the shaft 404. 10 The user allows the first member 304 to rotate until the wheel 406 of the jockey wheel 400 contacts the ground 504. The user then rotates the crank handle 408 of the jockey wheel 400 to adjust the extension of the shaft 404 from the outer tube 402 so as to position the wheel 406 properly in contact with the ground 504 and with the shaft 404 in a generally vertical or upright orientation 15 as per Figure 5c. It should be noted that positioning the shaft 404 of the jockey wheel 400 in a generally vertical or upright orientation with the wheel 406 in contact with the ground 504 may require the user to operate the crank handle 408 to retract 20 (that is, shorten) the shaft 404 depending on the height of the coupling 300 relative to the ground and the length of the shaft 404 upon deployment. For example, the length of the shaft 404 may be such that the shaft 404 may adopt the generally vertical or upright orientation with the wheel 406 either 25 suspended above the ground 504, or just in contact with the ground 504 without operating the crank handle 408. In either of these cases, the pin 372 will rest on the lower rounded end of the slot 362. However, the length of the shaft 404 may be such that the jockey wheel 400 30 may not be able to adopt the generally vertical or upright orientation. For example, the length of the shaft 404 may mean that the wheel 406 engages the ground 504 with the shaft 404 inclined or angled to the extent that a side -18 edge of the first member 304 abuts with a bottom portion of a projection means 352 thus preventing the first member 304 from further rotation. In this case, the shaft 404 will need to be retracted into the outer tube 402 of the jockey wheel 400 to thus allow the shaft 404 to adopt the generally vertical or upright 5 orientation and with the first member 304 in the lower position. Upon the shaft 404 having adopted the above described generally vertical or upright orientation, the user then operates the crank handle 408 to extend the shaft 404 out of the outer tube 402 so that the amount of shaft 404 between 10 the wheel 406 and the pin 372 is lengthened. As the shaft 404 is extended, the first member 304 is displaced upwardly (i.e. translated along the slots 362) and slides along second member 306 towards the upper position, at which position a section of each of the side edges 326, 328 of the first member 304 is juxtaposed with the respective projecting portions 352. During the upward 15 displacement of the first member 304, the pin 372 travels along the slots 362 and holds the first member 304 to the second member 306 in a manner which permits the sliding movement therebetween. The above operative sequence is best illustrated in Figures 5c and 5d. In 20 Figure 5c, the pin 372 is resting on the lower rounded edge 368 of the slot 362 and the jockey wheel 400 is orientated in the upright configuration with the wheel 406 in contact with the ground 504. In Figure 5d, crank handle 408 has been operated to cause upward displacement of the first member 304 along the second member 306 until the pin 372 bears against the upper rounded end 25 366 of the slot 362. At this point, a compression force caused by the coupling 300 supporting the weight of the trailer on the jockey wheel 400 holds the first member 304 in the upper position at which position the projecting portions 352 prevent rotation of the first member 304, and thus the shaft 404. The jockey wheel 400 is thus locked in this upright position. This is the operative position 30 of the jockey wheel 400 when used as a support mechanism (i.e. to hold the trailer in the correct orientation or manoeuvre the trailer when it is not hitched to a vehicle.) - 19 Example 2: Stowing a Jockey Wheel from a Deployed Position Referring initially to Figure 5d, it can be seen that the jockey wheel 400 is orientated in the deployed position with the coupling 300 supporting the weight 5 of the trailer on the jockey wheel 400. In this position, and as previously explained, the first member 304 is located at the upper position and thus restricted from rotation by the projecting portions 352. To stow the jockey wheel 400 when the trailer is mounted on a vehicle (or 10 other support means) the user first operates the crank handle 408 to retract the shaft 404 into the outer tube 402, and thus reduce the distance between the pin 372 and the bottom of the wheel 406. As the shaft 404 is retracted into the outer tube 402 the pin 372 will translate or 15 slide downwardly along the slots 362 and in so doing direct the first member 304 towards the lower position. Hence at least initially the wheel 406 will remain grounded due to the downward translation of the pin 372 and attached first member 304. This movement of the pin 372 along the slots 362, and thus downward movement of the first member 304, continues until the pin 372 20 bears against the lower rounded end 368 of each slot 362. At this point further operation of the crank handle 408 to retract the shaft 404 into the outer tube 402 will cause the wheel 406 to be raised off the ground 504. Once the pin 372 is bearing against the lower rounded end 368 of the slot 362, the first member 304, and thus the shaft 404 and attached wheel 406 are free to rotate. 25 The jockey wheel 400 can then be rotated to the stowed position shown in Figure 5a. Rotating the jockey wheel 400 to the stowed position aligns the locking pin 332 with the hole 340. The locking pin 332 can then be engaged with the hole 340 30 to secure the jockey wheel 400 in the stowed position. In this position the jockey wheel 400 is not likely to be damaged by inadvertent impact.

- 20 From the above description it will be appreciated that it is desirable for the user to return the jockey wheel 400 to the stowed position (Figure 5a) when it is not in use. However, it will also be appreciated that if the user only returns the jockey wheel to the position shown in Figure 5c (i.e. the user retracts the shaft 5 404 to move the wheel 406 off the ground until the shank 370 of the pin 372 bears against the rounded lower end 368 of each slot 362) then the jockey wheel 400 may better avoid damage due to inadvertent impact. This is because in this position, the jockey wheel 400 is free to pivot about the axis of the pin 372 and thus if it strikes an object (e.g. a raised portion on a road way) 10 then it will be able to pivot upwardly towards the chassis 502 of the trailer and thereby hopefully move over the object in a manner that avoids or at least minimises impact damage to the jockey wheel 400. In conclusion, it must be appreciated that there may be other variations and 15 modifications to the configurations described herein which are also within the scope of the present invention.

Claims (20)

1. A coupling for attaching a support mechanism to a vehicle, the coupling including a first member arranged for connection to the support mechanism; a 5 second member arranged for connection to the vehicle; a connection between the first member and the second member, the connection arranged to enable translating movement of the first member relative to the second member between an upper position in which the first member is substantially prevented from pivoting relative to the second member and a lower position in which the 10 first member is free to pivot relative to the second member, and wherein the second member includes at least two abutment means arranged so that when the first member is located in the upper position the first member is located between the two abutment means so that the first member is substantially prevented from pivoting relative to the second member. 15

2. A coupling according to claim 1 wherein each of the abutment means is arranged to contact an edge section of the first member when in the upper position to substantially prevent pivoting of the first member. 20

3. A coupling according to claim 2 wherein the first member has a generally square configuration and the edge sections include portions of the opposite sides edges of the square configuration.

4. A coupling according to any one of the preceding claims wherein the 25 first member includes one or more support elements projecting outwardly from a surface of the first member and arranged for supporting and/or locating the support mechanism.

5. A coupling according to claim 4 wherein each support element includes 30 one or more folds or a web or rib disposed on the surface. - 22

6. A coupling according to any one of the preceding claims wherein the second member includes a plate and the abutment means are attached to the plate or are integrally formed with the plate. 5

7. A coupling according to any one of the preceding claims wherein each abutment means includes a projection shaped so that the two abutment means define a receiving channel having a width which progressively narrows from a first width to a second width to provide a guide for directing the first member into the upper position during movement of the first member from the lower 10 position to the upper position.

8. A coupling according to any one of the preceding claims wherein the connection includes a pivot joint adapted to connect the first member and second member and to permit sliding movement of the first member along the 15 second member between an upper position and a lower position.

9. A coupling according to claim 8 wherein the pivot joint includes a slot and pin arrangement, the pin being able to translate along the length of the slot. 20

10. A coupling according to claim 9 wherein the slot defines an axis of motion of the pin.

11. A coupling according to claim 9 or claim 10 wherein the pin is attached 25 to the first member and the second member incorporates the slot.

12. A coupling according to any one of claims 9 to 11 wherein the slot extends from an upper portion of the second member towards a lower portion of the second member to define an axis of translation or motion. 30 - 23

13. A coupling according to claim 9 wherein the pin extends from the first member and the second member incorporates a pair of aligned slots, each slot arranged to receive a portion of a shank of the pin. 5

14. A support for a vehicle, the support including: a support mechanism; and a coupling including a first member arranged for connection to the support mechanism; a second member arranged for connection to the vehicle; a connection between the first member and the second member, the 10 connection arranged to enable translating movement of the first member relative to the second member between an upper position in which the first member is substantially prevented from pivoting relative to the second member and a lower position in which the first member is free to pivot relative to the second member, and wherein the second member includes at least two 15 abutment means arranged so that when the first member is located in the upper position the first member is located between the two abutment means so that the first member is prevented from pivoting relative to the second member.

15. A support for a vehicle according to claim 14 wherein the coupling is in 20 accordance with any one of claims 1 to 13.

16. A support for a vehicle according to claim 14 or claim 15 wherein the support mechanism is a jockey wheel. 25

17. A trailer fitted with a support according to any one of claims 14 to 16.

18. A trailer fitted with a coupling and a support mechanism including a jockey wheel and substantially as hereinbefore described with reference to Figures 3 to Figure 5d of the accompanying drawings. 30 -24

19. A coupling for attaching a support mechanism to a vehicle chassis substantially as hereinbefore described with reference to Figure 3 to Figure 5d of the accompanying drawings. 5

20. A support for a vehicle chassis substantially as hereinbefore described with reference to Figure 3 to Figure 5d of the accompanying drawings.