GB2482688A

GB2482688A - A trolley which can collapse to have all the wheels in the same plane as the trolley

Info

Publication number: GB2482688A
Application number: GB1013384.1A
Authority: GB
Inventors: Trevor Neil Martin
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-08-09
Filing date: 2010-08-09
Publication date: 2012-02-15
Also published as: WO2012020241A1; GB201013384D0

Abstract

A foldable trolley 1 comprising a frame 7, a pair of main wheels 8 and an auxiliary wheel 2, the foldable trolley being movable between a folded and unfolded configuration, the auxiliary wheel 2 being movable between an in-use position where the plane of the auxiliary wheel is substantially parallel (as show in figure) to the planes of the pair of main wheels of the trolley in its unfolded configuration, and a stored / folded position where the plane of the auxiliary wheel is substantially parallel to a main plane of the trolley in its folded configuration (see figure 1). The cart / trolley further comprises a mechanism for moving / folding the auxiliary wheel, the mechanism requiring only a single operation to move the auxiliary wheel between the stored position and the in-use position. The operating mechanism may be actuated manually, or preferably connected such that collapsing the cart automatically operates it. The cart is preferably a golf trolley.

Description

A Foldable Trolley and an Auxiliary Wheel for a Trolley The invention relates to a foldable trolley, for example a golf trolley, and an auxiliary wheel for a foldable trolley that is provided with an actuating mechanism capable of moving the auxiliary wheel from a stored position to an in-use position where in the stored position the rotational plane of the wheel is parallel with a principle plane of the folded trolley so as to minimise the folded size, and in the in-use position the plane of the wheel is parallel with the in-use planes of the main wheels of the trolley. In so moving the auxiliary wheel between the two positions, the actuating mechanism causes the plane of the auxiliary wheel to be rotated through a predefined angle about a first axis and at the same time to pivot the auxiliary wheel about a second axis in order to move the auxiliary wheel clear of any mounting fixtures, and also to rotate the plane of the auxiliary wheel about a third axis that transects the second axis in order to move the plane of the wheel into the correct alignment. The second axis may transect the first axis.

Auxiliary wheel assemblies in general may be configured to be moved between stored and in-use positions without altering the rotational plane of the wheel, but this may limit the possibilities for space saving or limit the size of the auxiliary wheel in order to achieve targets for folded size. See for example US2008/252027 and US2005/121865. Alternatively, there are arrangements used where the auxiliary wheel is folded in stages to achieve a desired movement where the rotational plane is changed between the stored and in-use positions in order that a more compact folded size, in particular where a large wheel is used, is achievable. However this is often at the expense of more complex user procedure with multiple steps and/or where the user is expected to manipulate wheel components directly and this may be awkward or inconvenient, and components may be mud-covered. See for example US2009/066056 and US2010/176577.

According to the present invention there is provided a foldable trolley comprising a frame, a pair of main wheels and an auxiliary wheel; the foldable trolley being movable between a folded configuration and an unfolded configuration; the auxiliary wheel being coupled to a wheel support and being movable between a stored position and an in-use position; in the in-use position the plane of the auxiliary wheel is parallel to the planes of the pair of main wheels of the foldable trolley in its unfolded configuration; in the stored position the plane of the auxiliary wheel is parallel or substantially parallel to a principal plane of the foldable trolley in its folded configuration; the foldable trolley further comprises a mechanism for moving the auxiliary wheel, wherein the mechanism requires only a single operation to move the auxiliary wheel between the stored position and the in-use position.

In one embodiment the plane of the auxiliary wheel in its in-use position is orthogonal to the plane of the auxiliary wheel when in its stored position.

The mechanism may be a user-operable mechanism comprising a trigger, such as a lever, handle or similar, located remote from the auxiliary wheel such that movement of the auxiliary wheel between the stored position and the in-use position can be achieved by operation of said trigger without user contact with the auxiliary wheel.

Alternatively, the mechanism may be connected to a mechanism for moving the pair of main wheels of the foldable trolley between their folded configuration and their unfolded configuration so that an action of a user in moving the pair of main wheels also moves the auxiliary wheel between its stored position and its in-use position.

The wheel support may be substantially U-shaped and comprise a pair of sides defining therebetween a recess for receiving the auxiliary wheel when in its in-use position.

Preferably the mechanism comprises a linkage coupling the auxiliary wheel to the wheel support, wherein the linkage comprises an actuator rotatable relative to the wheel support about a first axis and a wheel arm assembly extending between the actuator and the auxiliary wheel, wherein rotation of the actuator about the first axis causes the plane of the auxiliary wheel to rotate about said first axis and also causes the wheel arm assembly to move to thereby pivot the plane of the auxiliary wheel about a second axis and to further rotate the plane of the auxiliary wheel about a third axis.

Preferably the single operation causes rotation of the actuator about the first axis.

Preferably the wheel arm assembly comprises a wheel-end to which the auxiliary wheel is rotatably mounted and an actuator-end which is pivotably mounted to the actuator such that the wheel arm assembly is pivotable about the second axis.

Preferably the actuator-end of the wheel arm assembly is mounted to the actuator to also be rotatable relative to the actuator about the third axis; wherein the second and third axes are perpendicular to each other.

Preferably the actuator end of the wheel arm assembly comprises a cam arrangement which interacts with a cam abutment surface to cause the wheel arm assembly to rotate about the third axis as the wheel arm assembly rotates about the first axis.

Preferably the cam abutment surface is provided by one or more of the wheel support and the wheel arm assembly.

Preferably the wheel arm assembly is provided with a crank along its length so that the third axis is other than coincident with the rotational axis of the auxiliary wheel.

Preferably the foldable trolley further comprises a surface along which the wheel arm assembly rides on rotation of the actuator about the first axis; wherein the profile of the surface causes the wheel arm assembly to pivot about the second axis.

Preferably the wheel arm assembly comprises at least one cam which is brought into and out of contact with the surface on rotation of the auxiliary wheel about the third axis.

The wheel arm may comprise at least one cam and the surface comprise at least one planar surface at an oblique angle to the first axis such that the at least one cam is brought into and out of contact with the at least one planar surface as the actuator rotates about the first axis.

Preferably pivoting of the wheel arm assembly about the second axis provides rotational clearance between the auxiliary wheel and the sides of the wheel support.

The foldable trolley may be a foldable golf trolley.

The present invention also provides an auxiliary wheel for a foldable trolley of the type described above.

The invention disclosed provides an improved design whereby an auxiliary wheel for a trolley can be moved between a stored position and an in-use position, allowing for the rotational plane of the wheel to be moved through an angle of 90 degrees, when actuated with a single-step user operation that can be made by lever or other mechanism positioned at a convenient place on the trolley remote from the auxiliary wheel, or made to be integral with the movement of the main wheels of the trolley.

An embodiment of the present invention will now be described, by way of example only, with reference to the following drawings, in which: Figure 1 is a perspective view of a trolley in the folded position; Figure 2 is a partial perspective view of the trolley in the in-use position; Figure 3 is a side elevation of the trolley shown in figure 1; Figure 4 is a side elevation of the trolley shown in figure 2; Figure 5 is an exploded view of the auxiliary wheel assembly in the folded position; and Figure 6 is an exploded view of the auxiliary wheel assembly in the in-use position.

A trolley 1 is provided with an auxiliary wheel assembly 2 so that in-use the trolley 1 is supported on, and can be manoeuvred on, the auxiliary wheel together with the main wheels 8 of trolley 1. Auxiliary wheel assembly 2 comprises a wheel assembly 3, a wheel arm assembly 4, a wheel actuator assembly 5 and a wheel support 6. The auxiliary wheel assembly 2 may be connected to a frame 7 or any other structure of trolley 1.

Wheel assembly 3 comprises a tyre 11 and a wheel 12 and is operably connected to wheel arm assembly 4. Wheel arm assembly 4 comprises a wheel arm 13, a hub 14 and an axle 15. Hub 14 is connected to wheel arm 13 at one end 16 of wheel arm 13 and axle 15 is connected to hub 14 whereupon wheel assembly 3 is rotatable about axle 15. Wheel arm 13 is provided with a crank 18 partway along its length. Crank 18 is arranged such that a plane can be defined to contain axis 20 of wheel arm 13 which is always parallel with the rotational plane of wheel assembly 3, and axle 15 is normal to both planes. Although this is not essential, it is convenient for defining the required movement of wheel arm 13 such that the plane of wheel assembly 3 will move between the stored alignment and the in-use alignment. Furthermore, by altering the angle and direction of crank 18 and/or the lengths of wheel arm 13 sections defined by axes 19 and/or 20, the characteristics of the actuator assembly can be optimised. At end 17 wheel arm 13 is connected to wheel actuator assembly 5.

Wheel actuator assembly 5 comprises pivot arm 21, rotor 22, spring 23, pin 24, actuator 25, housing 26 and sleeve 27. Wheel arm 13 at end 17 is fixedly connected to end 31 of pivot arm 21 of wheel actuator assembly 5.

Towards end 32, pivot arm 21 is operably connected to rotor 22 about axis 33 on pin 24 so that pivot arm 21 can rotate about axis 33 relative to rotor 22 to provide a pivotal movement in a plane parallel with faces 39 and 40 of pivot arm 21 at all times. Torsion spring 23 is received into recess 42 of pivot arm 21 and interacts with both pivot arm 21 and rotor 22 to provide a biasing force that urges pivot arm 21 to rotate relative to rotor 22 in a counter-clockwise sense about axis 33 when viewed in direction of arrow 67, and return it to a rest position once any force acting to cause pivotal movement has been removed. In a preferred arrangement, the rest position is such that pivot arm 21 and rotor 22 are coaxial, but other arrangements are possible. Towards end 31, pivot arm 21 is provided with cylindrical surface 34 and cam 35 that both cooperate with wheel support 6 to provide for the pivotal movement of pivot arm 21 in a clockwise sense about axis 33 against the biasing force of spring 23. Further, surface 34 cooperates with wheel support 6 to define the rest position that pivot arm 21 assumes under the biasing action of spring 23, although a mechanical stop (not shown) provided between pivot arm 21 and rotor 22 could otherwise be used to achieve this.

Rotor 22 is provided with cylindrical surface 53 that is received into bore 71 of actuator 25 such that rotor 22 can rotate about axis 59 within actuator 25. Flange 55 of rotor 22 abuts with shoulder 72 of actuator 25 and prevents rotor 22 from moving axially in direction shown by arrow 60 relative to actuator 25. Rotor 22 is provided with cam 61 that cooperates with both housing 26 and sleeve 27 to influence the rotation of rotor 22 within actuator 25. Cam 61 comprises a cylindrical portion 62 with surface 64 that cooperates with housing 26 and an elongated portion 63 towards one side with surface 65 that cooperates with sleeve 27.

Actuator 25 is provided with cylindrical surface 73 that is received into bore 81 of housing 26 such that actuator 25 can rotate about axis 90 within housing 26.

Actuator 25 is provided with a raised ring 76 and face 77 of ring 76 abuts with face 84 of housing 26 to prevent axial movement of actuator 25 in direction of arrow 91 with respect to housing 26. Rotor 22 is provided with spherical surface 58 towards end 52 and with centre coincident with intersection of axis 59 of rotor 22 and axis 90 of actuator 25, so that two lines of contact are maintained between surface 58 and bore 81 of housing 26 at all times. Thus rotor 22 is permitted to rotate within actuator 25 and therefore within housing 26 also, but is prevented from moving axially on axis 59 in a direction opposite to arrow 60. Rotor 22 is positioned within actuator 25 such that in an initial state, surface 64 of cam 61 is in contact with face 85 of housing 26 and rotation of actuator 25 within housing 26 in a counter-clockwise sense about axis 90, when viewed in direction of arrow 91, is not possible. Surface 64 of cam 61 is also in contact with face 83 of housing 26.

As actuator 25 rotates within housing 26 in a clockwise sense about axis 90, and rotor 22 rotates with actuator 25, surface 64 of cam 61 remains in sliding contact with face 83 of housing 26, and this prevents counter-clockwise rotation of rotor 22 within actuator 25 about axis 59 when viewed in direction of arrow 60. As actuator 25 continues to rotate within housing 26, a point is reached at which surface 64 of cam 61 abuts with face 86 of housing 26. From this point, further clockwise rotation of actuator 25 within housing 26 causes rotor 22 to rotate within actuator 25 in a clockwise sense about axis 59. As actuator 25 continues to rotate within housing 26 and rotor 22 rotates within actuator 25, cam 61 describes an arc about axis 59 and surface 64 of cam 61 moves away from face 83 of housing 26 until cylindrical portion 62 of cam 61 is vertical with respect to axis 59 and has rotated through an angle a. As actuator 25 continues to rotate within housing 26 and rotor 22 rotates within actuator 25, cam 61 continues to follow the path of the arc and surface 64 of cam 61 moves back towards face 83 of housing 26. At an angle of 2a, surface 64 of cam 61 is once again in contact with face 83 of housing 26, and if actuator and housing 26 are constrained to prevent axial movement relative to one another, no further rotation of rotor 22 within actuator 25 is possible and therefore no further rotation of actuator 25 within housing 26 is possible either.

In a preferred arrangement, the axis 59 of rotor 22 and the axis 90 of actuator 25 are orthogonal and the angle 2a can be defined from trigonometric relationships to be the angle required to rotate wheel assembly 3 about axis 19 of wheel arm 13 and so move the plane of the wheel assembly 3 from the stored plane to the in-use plane following rotation of the wheel arm assembly 4 about axis 90 between the stored position and the in-use position. For this reason it is also convenient to position the wheel actuator assembly 5 so that axis 90 of actuator 25 is normal to a plane that is defined by the three points given by the intersect of axes 19 and 20 of wheel arm 13 in firstly the stored position 19' and 20', point A, and secondly the in-use position 19'' and 20'', point B; and point C given by the intersect of axis 59 of rotor 22 and axis 90 of actuator 25. Clearly other arrangements could be used.

Actuator 25 is also provided with cylindrical surface 74 that is coaxial with surface 73 and is received into bore 92 of sleeve 27 such that actuator 25 can rotate about axis 90 within sleeve 27. Face 78 of ring 76 abuts with face 95 of sleeve 27 to prevent axial movement of actuator 25 in direction opposite to arrow 91 with respect to sleeve 27.

-10 -Sleeve 27 is provided with cut-outs 96 and 97 in face 95 to accommodate cam 61 of rotor 22 as rotor 22 rotates within actuator 25 and cam 61 traces an arcing path about axis 59 of rotor 22. Sleeve 27 is positioned to be in fixed alignment with housing 26 with face 86 of housing 27 offset a small distance form face 98 of cut-out 96, such that when rotor 22 has rotated through an angle of 2cc, elongated portion 63 of cam 61 is received into cut-out 96 and surface of cam 61 is positioned against face 98 of cut-out 96.

Cut-out 97 is provided to accommodate the vertical displacement of cylindrical portion 62 of cam 61 as cam 61 traces the arcing path.

If actuator 25 is now rotated in a counter-clockwise sense about axis 90 when viewed in direction of arrow 91 within sleeve 27 (and housing 26), face 98 of cut-out 96 will act on surface 65 of cam 61 and cause rotor 22 to rotate within actuator 25 in a counter-clockwise sense about axis 59. As rotor 22 rotates, cam 61 will again trace the arcing path described above, but in the opposite direction.

Once rotor 22 has rotated through an angle of 2cr, surface 64 of cam 61 will again rest on face 83 of housing 26, and elongated portion 63 of cam 61 will be positioned such that surface 65 is coincident with face 95 of sleeve 27.

Therefore actuator 25 can now continue to rotate freely within sleeve 27 (and housing 26) and any further rotation of rotor 22 is prevented as cam 61 is guided between face 83 of housing 26 and face 95 of sleeve 27. Actuator 25 can continue to rotate in a counter-clockwise sense about axis until face 64 of cam 61 once again abuts with face 85 of housing 26. In this way the rotary movement of rotor 22 and hence the positioning of wheel assembly 3 onto the correct in-use plane can be controlled to occur within a small part -11 -of the total movement of the wheel arm assembly 4 between the stored position and the in-use position.

Housing 26 is provided with cut-out 89 to accommodate the complex movement of pivot arm 21 as pivot arm 21 pivots relative to rotor 22 and rotor 22 rotates within actuator 25 about axis 59 and rotor 22 also rotates with actuator 25 within housing 26 about axis 90. At one end of cut-out 89 is face 87 and at the other end of cut-out 89 is face 88.

Faces 87 is arranged to be coplanar with face 40 of pivot arm 21 when actuator 25 is rotated fully in a counter-clockwise sense about axis 90 when viewed in direction of arrow 91. Face 88 is arranged to be coplanar with face 39 of pivot arm 21 when actuator is rotated fully clockwise.

In this way pivot arm 21 is locked in both the stored and the in-use positions and the orientation of the wheel assembly 3 on the desired planes can be precisely controlled.

Wheel actuator assembly 5 is received into one end 106 of wheel support 6 and housing 26 and sleeve 27 are fixedly connected to wheel support 6 such that actuator 25 is free to rotate between housing 26 and sleeve 27 but axial movement on axis 90 is minimised. Wheel support 6 is provided with cut-outs 101 and 102 to receive pivot arm 21 of wheel actuator assembly 5 in the stored position and the in-use position respectively. Cut-outs 101 and 102 are connected by ramped surfaces 103 and 104 with apex 105. The angles of the ramped surfaces 103 and 104 are determined to ensure that the wheel assembly 3 can be moved between the stored and the in-use positions without being impeded by the wheel support 6 or other fixtures. If actuator 25 of wheel actuator assembly 5 is rotated within housing 26 and sleeve 27, surface 34 of pivot arm 21 makes contact with ramped -12 -surfaces 103 or 104 and pivot arm 21 is forced to move in a pivotal sense relative to rotor 22. As surface 34 of pivot arm 21 moves across surface 103 or 104 and beyond apex 105, biasing force of spring 23 urges pivot arm 21 towards, and causing it to remain in contact with, the opposing ramped surface 104 or 103. In this way, while the pivot arm 21 is moved between cut-outs 101 and 102, between the stored position and the in-use position or vice versa, pivot arm 21 is also made to move pivotally and wheel assembly 3 moves clear of the wheel support 6 or other fixtures. In practice, either or both ramped surfaces 103 and 104 may comprise more than one ramped surface with different angles to change the rate of pivotal movement of pivot arm 21 and thus reducing the effort required to rotate actuator 25.

Furthermore, ramped surfaces 103 and 104 could be replaced with curved surfaces to achieve a similar affect, or a combination of ramped and curved surfaces.

Cut-outs 101, 102 of wheel support 6 may either or both be provided with an undercut 112 such that when wheel assembly 3 is in the stored position and/or the in-use position, and pivot arm 21 is received into cut-outs 101 and/or 102, pivotal movement of pivot arm 21 against the biasing force of spring 23 is prevented by undercut 112.

Thus spring 23 only performs a function when wheel assembly 3 is being moved between the stored position and the in-use position and the duty rating of spring 23 can be specified accordingly.

Pivot arm 21 is also provided with cam 35 which cooperates with ramped surfaces 103 and 104 to increase the pivotal movement particularly as pivot arm 21 moves across ramped surfaces 103 and 104 in the region of apex 105 and as pivot arm 21 moves across apex 105. As actuator 25 is -13 -rotated in a clockwise sense about axis 90, surface 34 of pivot arm 21 moves across ramped surface 103, but because ramped surface 103 is at an oblique angle to axis 90, the line of contact between surface 34 and ramped surface 103 moves around the circumference of surface 34. (From a viewpoint on end 31 of pivot arm 21 this would appear as though pivot arm 21 is rotating on ramped surface 103 in a counter-clockwise sense.) Therefore by suitably positioning cam 35 on surface 34 of pivot arm 21, at some point before pivot arm 21 reaches apex 105, surface 36 of cam 35 will come into contact with ramped surface 103 and from this point forward the line of contact will transfer to cam 35, and cam 35, not surface 34, will define the pivotal movement of pivot arm 21 relative to rotor 22. As pivot arm 21 moves over apex 105, surface 38 of cam 35 will sweep around apex until surface 37 of cam 35 comes into contact with ramped surface 104. As actuator 25 continues to rotate in a clockwise sense, the line of contact between surface 37 of cam 35 and ramped surface 104 will move down surface 37 and at some point between apex 105 and cut-out 102, surface 34 of pivot arm 21 will come into contact with ramped surface 104 and the line of contact will transfer back to surface 34. From this point forward surface 34, not cam 35, will define the pivotal movement of pivot arm 21 relative to rotor 22. As actuator 25 is rotated in a counter-clockwise sense about axis 90, and pivot arm 21 moves first across ramped surface 104, the reverse sequence of events will be observed. In this way it is possible to generate much greater pivotal movement than would be possible using just a simple cylinder acting on a ramped surface, and this enables the angles of ramped surfaces 103, 104 to be reduced thus reducing the effort required to rotate actuator 25. This is -14 -particularly useful because the plane of pivotal rotation (that can be defined by faces 39, 40 of pivot arm 21) is necessarily caused to move towards the ramped surfaces at either extremes of rotation of actuator 25. Therefore at the start of the rotation of actuator 25 the effective cam angle formed between pivot arm 21 and either ramped surface 103 or 104, can be very steep as the angle between face 39, of pivot arm 21 and ramped surface 103, 104 tends to be small. As the rotation continues, the effective cam angle formed between face 39, 40 of pivot arm 21 and either ramped surface 103 or 104 reduces and the use of cam 35 with pivot arm 21 takes advantage of this phenomenon. Therefore the rate of pivotal rotation of pivot arm 21 is variable and is reduced when the mechanism is least able to deliver this movement and increased when the mechanism is most able to deliver the movement.

Cam 35 of pivot arm 21 may also be used to locate pivot arm in the stored position and/or the in-use position by receiving cam 35 into recesses (not shown) provided in wheel support 6 at either end of ramped surfaces 103 and/or 104. In this way, pivot arm 21 can be accurately located in the stored position and/or the in-use position and the orientation of the wheel assembly 3 on the desired planes can be precisely controlled. This feature can be used in combination with, or to replace the function of faces 87 and 88 of cut out 89, housing 26 to locate on faces 40 and 39 of pivot arm 21 in the stored position and in-use position respectively.

Wheel support 6 is provided with recess 108 to provide clearance for wheel assembly 3 when moving between stored position and in-use position and in the in-use position. At ends 106 and 107 of wheel support 6 are provided faces 109 -15 -and 110 respectively that are arranged to be coplanar with most extreme part of tyre 11 of wheel assembly 3 when in the stored position so that faces 109 and 110 and tyre 11 act together to provide a stable 3-point platform on which trolley 1 can stand when folded.

Wheel support 6 may be provided with a boot or other flexible seal arrangement (not shown) with an opening to accept pivot arm 21 and/or wheel arm 13 and so allow movement of wheel arm assembly 4 between the stored position and the in-use position whilst preventing ingress of dirt and water into actuator assembly 5.

Wheel support 6 has openings ill for receiving members of tubular frame 7 of trolley 1 and is fixedly connected to frame 7. Frame 7 carries the main wheels 8 and a mechanism (not shown) for folding the main wheels 8.

In a simple arrangement, actuator 25 of actuator assembly 5 may be provided directly with lever 9 connected to actuator 25 and capable of imparting the rotary force needed to move the auxiliary wheel assembly 2 between the stored position and the in-use position. In a preferred arrangement, the actuator 25 of the actuator assembly 5 may be connected to a mechanism remotely so that auxiliary wheel assembly 2 can be operated by a remote lever or other device, and using some type of bi-stable arrangement, the wheel assembly 3 may be secured in both the stored position and the in-use position. In an alternative arrangement, the mechanism may be connected to be integral with the mechanism (not shown) that moves the main wheels 8 of trolley 1 from the stored position to the in-use position so that wheel assembly 3 of auxiliary wheel assembly 2 moves in unison with main wheels 8 between the two states.

-16 -In the stored position the plane of the auxiliary wheel is parallel or substantially parallel to a principal plane of the foldable trolley in its folded configuration. In the embodiment as illustrated in Figure 1, the principal plane of the foldable trolley is the plane perpendicular to the axles of both of the main wheels 8 in their stowed configuration as shown in Figure 1. Figure 3 is a view of the foldable trolley viewed along the principal plane of the foldable trolley.

Claims

-17 -Claims: 1. A foldable trolley comprising a frame, a pair of main wheels and an auxiliary wheel; the foldable trolley being movable between a folded configuration and an unfolded configuration; the auxiliary wheel being coupled to a wheel support and being movable between a stored position and an in-use position; in the in-use position the plane of the auxiliary wheel is parallel to the planes of the pair of main wheels of the foldable trolley in its unfolded configuration; in the stored position the plane of the auxiliary wheel is parallel or substantially parallel to a principal plane of the foldable trolley in its folded configuration; the foldable trolley further comprises a mechanism for moving the auxiliary wheel, wherein the mechanism requires only a single operation to move the auxiliary wheel between the stored position and the in-use position.
2. A foldable trolley as claimed in claim 1 wherein the mechanism is a user-operable mechanism comprising a trigger, such as a lever, handle or similar, located remote from the auxiliary wheel such that movement of the auxiliary wheel between the stored position and the in-use position can be achieved by operation of said trigger without user contact with the auxiliary wheel.
3. A foldable trolley as claimed in claim 1 wherein the mechanism is connected to a mechanism for moving the pair of main wheels of the foldable trolley between their folded configuration and their unfolded configuration so that an -18 -action of a user in moving the pair of main wheels also moves the auxiliary wheel between its stored position and its in-use position.
4. A foldable trolley as claimed in any preceding claim wherein the wheel support is substantially U-shaped and comprises a pair of sides defining therebetween a recess for receiving the auxiliary wheel when in its in-use position.
5. A foldable trolley as claimed in any preceding claim wherein the mechanism comprises a linkage coupling the auxiliary wheel to the wheel support, wherein the linkage comprises an actuator rotatable relative to the wheel support about a first axis and a wheel arm assembly extending between the actuator and the auxiliary wheel, wherein rotation of the actuator about the first axis causes the plane of the auxiliary wheel to rotate about said first axis and also causes the wheel arm assembly to move to thereby pivot the plane of the auxiliary wheel about a second axis and to further rotate the plane of the auxiliary wheel about a third axis.
6. A foldable trolley as claimed in claim 5 wherein the single operation causes rotation of the actuator about the first axis.
7. A foldable trolley as claimed in claim 5 or claim 6 wherein the wheel arm assembly comprises a wheel-end to which the auxiliary wheel is rotatably mounted and an actuator-end which is pivotably mounted to the actuator such that the wheel arm assembly is pivotable about the second axis.

-19 -
8. A foldable trolley as claimed in claim 7 wherein the actuator-end of the wheel arm assembly is mounted to the actuator to also be rotatable relative to the actuator about the third axis; wherein the second and third axes are perpendicular to each other.
9. A foldable trolley as claimed in claim 7 or claim 8 wherein the actuator end of the wheel arm assembly comprises a cam arrangement which interacts with a cam abutment surface to cause the wheel arm assembly to rotate about the third axis as the wheel arm assembly rotates about the first axis.
10. A foldable trolley as claimed in claim 9 wherein the cam abutment surface is provided by one or more of the wheel support and the wheel arm assembly.
11. A foldable trolley as claimed in any of claims 5 to 10 wherein the wheel arm assembly is provided with a crank along its length so that the third axis is other than coincident with the rotational axis of the auxiliary wheel.
12. A foldable trolley as claimed in any of claims 5 to 11 further comprising a surface along which the wheel arm assembly rides on rotation of the actuator about the first axis; wherein the profile of the surface causes the wheel arm assembly to pivot about the second axis.
13. A foldable trolley as claimed in claim 12 wherein the wheel arm assembly comprises at least one cam which is -20 -brought into and out of contact with the surface on rotation of the auxiliary wheel about the third axis.
14. A foldable golf trolley as claimed in claim 12 wherein the wheel arm comprises at least one cam and the surface comprise at least one planar surface at an oblique angle to the first axis such that the at least one cam is brought into and out of contact with the at least one planar surface as the actuator rotates about the first axis.
15. A foldable trolley as claimed in any of claims 5 to 14 when dependent on claim 3 wherein pivoting of the wheel arm assembly about the second axis provides rotational clearance between the auxiliary wheel and the sides of the wheel support.
16. A foldable trolley as claimed in any preceding claim wherein the foldable trolley is a foldable golf trolley.
17. An auxiliary wheel for a foldable trolley of any preceding claim.
18. A foldable trolley or an auxiliary wheel for a foldable trolley substantially as hereinbefore described with reference to and as shown in the accompanying drawings.