Vehicle trailer arrangement

Abstract

Trailer (1) has roll control suspension arrangement (2) with load support member or frame (3) to support a load (6) and is pivotally connected to an undercarriage (7) by roll pivot (8) having roll pivot axis (9). Frame roll adjuster (41) acts between the undercarriage (7) and the load support member or frame (3), such that, as the frame roll adjuster contracts, the load support member or frame (3) and the load (6) roll to the left about the roll pivot axis (9), i.e. the left side of the load support member or frame (3) and the load (6) move closer towards the undercarriage. As the frame roll adjuster extends, load support member or frame 3 and load 6 roll to the right about roll pivot axis (9), i.e. the right side of the load support member or frame (3) and the load 6 move closer towards the undercarriage.

Description

VEHICLE TRAILER ARRANGEMENTTECHNICAL FIELD

[0001] The present invention relates to trailers that are towed by vehicles and in particular to trailers with adjustment of roll attitude.BACKGROUND

[0002] The control of the roll attitude of trailers is generally passive and results for example when turning left with a roll to the right due to centrifugal force. The roll is limited by from the heave stiffness of the support spring(s) on the left wheel(s) which are extending and the heave stiffness of the support spring(s) on the right wheel(s) which are contracting or compressing. Additionally anti-roll bars can be used which are substantially laterally extending torsion bars activated by motion of the left wheel(s) relative to the right wheel(s). Anti-roll bars provide roll stiffness without heave stiffness.

[0003] Active suspension for vehicles is known for providing roll attitude adjustment such as roll angle compensation (reducing or preventing roll of the vehicle body relative to the ground) or roll-in (driving the roll angle of the vehicle body to towards the inside of the turn). This is usually performed by either adjusting the support springs or the anti-roll bar. In either case the support springs or the anti-roll bar are provided between the suspension arms of the wheels the chassis or body. Adjusting the support springs can be performed by changing a fluid volume in fluid support springs or in actuators parallel to the support springs to extend or contract the springs as disclosed in European patent number 0569429 or alternatively it can be by adjusting the mounts between the support springs and the body as disclosed in United States patent number 6,249,728. An example of actively adjusting the antiroll bar is shown in Figure 7 of International Patent Application Publication Number W02009 / 064640.

[0004] Adjusting the springs, either by changing the fluid volume in a fluid support spring or by adjusting the spring mount between spring and body is that the rollangle adjustment possible of the vehicle body is directly related to an increase in spring length or required wheel travel to maintain a minimum desired wheel extension / compression motion at any time. This leads to difficulty in fitting the active adjustment arrangements into a vehicle and this is particularly difficult in trailers where the load volume restricts the space available for suspension components.

[0005] It would therefore be desirable to provide a suspension arrangement to permit active adjustment of roll angle of a load receiving portion of a trailer that overcomes one or more disadvantages of the prior art.

[0006] It is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.SUMMARY

[0007] According to a first aspect of the invention there is provided a suspension arrangement for a trailer, the trailer including: a load support member or frame for supporting a load; at least one left wheel and at least one right wheel; the at least one left wheel and at least one right wheel being connected to the load support member or frame by the suspension arrangement, wherein the suspension arrangement further includes: an undercarriage, the load support member or frame being pivotally connected to the undercarriage by a roll pivot having a pivot axis oriented or extending in at least a longitudinal direction; at least one left suspension arm to locate the at least one left wheel relative to the undercarriage and at least one right suspension arm to locate the at least one right wheel relative to the undercarriage; a respective support means for each respective at least one left and at least one right suspension arm for supporting the undercarriage above the least one left and at least one right wheel.

[0008] Another aspect of the present invention provides a suspension arrangement for a trailer, the trailer including: a load support member or frame for supporting a load; at least one left wheel and at least one right wheel; the at least one left wheeland at least one right wheel being connected to the load support member or frame by the suspension arrangement, wherein the suspension arrangement further includes: an undercarriage pivotally connected to the load support member or frame by a roll pivot having a pivot axis oriented or extending in at least a longitudinal direction; at least one left suspension arm to locate the at least one left wheel relative to the undercarriage and at least one right suspension arm to locate the at least one right wheel relative to the undercarriage; at least one left support means for at least partially supporting the undercarriage above the at least one left wheel and at least one right support means for supporting the undercarriage above the at least one right wheel.

[0009] The suspension arrangement may include at least one frame roll adjuster connected between the load support member or frame and the undercarriage to adjust or drive a roll position of the load support member or frame relative to the undercarriage.

[0010] The suspension arrangement may include an undercarriage roll adjustment arrangement connected between the undercarriage and the wheels or between the undercarriage and the suspension arms.

[0011] The frame roll adjuster may be an electro-magnetic actuator, a fluid ram such as a hydraulic ram or any other form of master cylinder.

[0012] The suspension arrangement may include an undercarriage roll adjustment arrangement to adjust or drive a roll position of the undercarriage relative to the wheels.

[0013] The at least one frame roll adjuster may be controlled by a trailer roll controller. A roll angle of the undercarriage relative to the wheels or relative to ground may be adjusted by roll adjusting the at least one left support means and the at least one right support means, said roll adjustment of the support means being controlled by the trailer roll controller. Alternatively, a roll angle of the undercarriage relative to the wheels or relative to ground may be adjusted by roll adjusting the at least one left support means and the at least one right support means, said rolladjustment of the support means being driven by, or controlled at least in part in dependence on, the roll position of the load support member or frame relative to the undercarriage.

[0014] The roll adjustment of the support means may include at least one left support adjustable mount for effectively adjusting the length of the at least one left support means and may include at least one right support adjustable mount for effectively adjusting the length of the at least one right support means. The left and right support adjustable mounts may be part of the undercarriage roll adjustment arrangement.

[0015] An anti-roll bar may be provided between the at least one left wheel and the at least one right wheel, the anti-roll bar being rotatably mounted to the undercarriage to permit heave motion of the undercarriage relative to the at least one left and at least one right wheel whilst providing a resistance to roll motions of the undercarriage relative to the at least one left and at least one right wheel, an undercarriage roll adjuster being provided in, on or in series with the anti-roll bar to provide roll adjustment of the undercarriage controlled by the trailer roll controller. The undercarriage roll adjuster may be an adjustable mount. The undercarriage roll adjuster may be part of the undercarriage roll adjustment arrangement.

[0016] At least one slave roll ram may be provided in parallel with the at least one frame roll adjuster, the at least one slave roll ram being connected between the load support member or frame and the undercarriage, the slave roll ram being driven by rotation of the load support member or frame relative to the undercarriage; the at least one slave roll ram including a left roll slave volume and a right roll slave volume; each respective at least one left and at least one right support means including a respective support compression chamber, the or each left support compression chamber forming a left support compression volume, the or each right support compression chamber forming a right support compression volume; the left roll slave volume being connected to the right support compression volume, the right roll slave volume being connected to the left support compression volume.

[0017] For example, the left and right roll slave volumes and the left and right support compression volumes may be fluid volumes, so as the load support member is rolled to the left (by the at least one frame roll adjuster) relative to the undercarriage, the left roll slave volume is compressed, transferring fluid into the right support compression volume, extending the right support means and rolling the undercarriage to the left relative to the wheels. As the left roll slave volume is compressed as the frame pivots relative to the undercarriage, the right roll slave volume is extended, drawing fluid from the left support compression volume, contracting the left support means which also rolls the undercarriage to the left relative to the wheels (and ground). Conversely, as the load support member is rolled to the right (by the at least one frame roll adjuster) relative to the undercarriage, the right roll slave volume is compressed, transferring fluid into the left support compression volume, extending the left support means and rolling the undercarriage to the right relative to the wheels. As the right roll slave volume is compressed as the frame pivots relative to the undercarriage, the left roll slave volume is extended, drawing fluid from the right support compression volume, contracting the right support means which also rolls the undercarriage to the right relative to the wheels and therefore the ground.

[0018] The slave ram(s), the left and right slave ram volumes and conduits connecting the left and right slave ram volumes to the left and right support compression volumes may be or form at least part of the undercarriage roll adjustment arrangement.

[0019] The respective left or right support means may be a respective double-acting ram, the or each of the respective left double acting rams including the respective left support compression chamber and a respective left support rebound chamber; the or each of the respective right double acting rams including the respective right support compression chamber and a respective right support rebound chamber; the or each respective left support compression chamber and right support rebound chamber being interconnected forming the left support compression volume and the or each respective right support compression chamber and left support rebound chamber being interconnected forming the right support compression volume.

[0020] The at least one slave roll ram may be in parallel with the frame roll adjuster.

[0021] The at least one slave roll ram may be a double-acting slave ram including the left roll slave volume opposing the right roll slave volume. Alternatively, the at least one slave roll ram may be a single-acting left roll slave ram including the left roll slave volume and a single-acting right roll slave ram including the right roll slave volume.

[0022] The frame roll adjuster may be a linear actuator or two single-acting fluid actuators or one double-acting fluid actuator.

[0023] The at least one left wheel may be a first left wheel and a second left wheel longitudinally spaced from the first left wheel; the at least one right wheel may be a first right wheel and a second right wheel longitudinally spaced from the first right wheel; the at least one left suspension arm including a first left suspension arm for at least partially locating the first left wheel relative to the undercarriage; and a second left suspension arm for at least partially locating the second left wheel relative to the undercarriage; the at least one right suspension arm including a first right suspension arm for at least partially locating the first right wheel relative to the undercarriage; and a second right suspension arm for at least partially locating the second right wheel relative to the undercarriage.

[0024] The at least one left support means may comprise a first left support means connected between the first left suspension arm and the undercarriage, and a second left support means connected between the second left suspension arm and the undercarriage; the at least one right support means may comprise a first right support means connected between the first right suspension arm and the undercarriage, and a second right support means connected between the second right suspension arm and the undercarriage.

[0025] The or each at least one left suspension arm and / or the or each at least one right suspension arm may be a respective radius arm or radius rod. Alternatively, the at least one left suspension arm may be a respective left suspension arm of a left multi-link suspension geometry (or location) arrangement of a respective left wheel,and similarly, the at least one right suspension arm may be a respective right suspension arm of a right multi-link suspension geometry (or location) arrangement of a respective right wheel. Advantages of the radius arm or radius rod is that as the undercarriage is rolled into a turn, the wheels lean into the turn, i.e. the outside wheel gains negative camber and the camber of the inside wheel is increased. So for a simple, easy to package wheel location geometry, the radius arm or radius rod maintains the wheels vertical relative to the undercarriage, resulting in wheels that have zero camber when the undercarriage is level, then negative camber (relative to ground) for the wheel on the outside of a turn and positive camber (relative to ground) for wheels on the inside of a turn.

[0026] Each respective support means may be connected between the respective suspension arm (such as a radius arm or radius rod) whereby motion of the suspension arm relative to the undercarriage corresponds to compression and / or extension of the respective support means.

[0027] The pivot axis of the roll pivot may lie in a vertical longitudinal plane. For example, the vertical longitudinal plane may be positioned equidistant from a centre of a contact patch of the or each of the at least one left wheel and a centre of a contact patch of the or each of the at least one right wheel.

[0028] The pivot axis of the roll pivot may be substantially horizontal. Alternatively, the pivot axis of the roll pivot may be inclined either upwards or downwards towards a front of the trailer. For example, the inclination may be at an angle of less than 2 degrees, less than 5 degrees or less than 10 degrees, or less than 20 degrees.

[0029] In one or more forms of the present invention, the trailer may include a hitch for connection to a towing vehicle. The hitch may be located on or relative to the load support member or frame. Alternatively, the hitch may be located on or relative to the undercarriage.

[0030] In one or more forms of the present invention, a roll attitude of the load support member or frame may be controlled by a trailer roll controller, including: a trailer speed sensor or input, and / or a trailer yaw rate sensor or input.

[0031] Additionally, the trailer roll controller may include a frame roll adjuster position sensor. Additionally or alternatively, the trailer speed sensor or input may include at least one wheel speed sensor or at least one input for a wheel speed sensor.

[0032] It will be convenient to further describe the invention by reference to the accompanying drawings which illustrate preferred aspects of the invention. Other embodiments of the invention are possible and consequently particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] One or more embodiments or examples of the present invention will hereinafter be described with reference to the accompanying Figures, in which:

[0034] Figure 1 is a schematic view of a trailer with suspension arrangement according to at least one embodiment of the present invention.

[0035] Figure 2 is a schematic view of a modification of the trailer with suspension arrangement of Figure 1 .

[0036] Figure 3 is a schematic view of an alternative modification of the trailer with suspension arrangement of Figures 1 and 2.

[0037] Figure 4 is a perspective view of an underside of a trailer with suspension arrangement according to at least one embodiment of the present invention.

[0038] Figure 5 is a perspective partial view of the suspension arrangement of Figure 4.

[0039] Figure 6 is a perspective view of an underside of the horsebox of the trailer of Figure 4.

[0040] Figure 7 is a perspective view of the suspension arrangement of the trailer of Figure 4.

[0041] Figure 8 is a perspective front three-quarter view of the trailer of Figure 4 rolling to the right.

[0042] Figure 9 is a perspective front three-quarter view of the suspension arrangement of the trailer of Figure 8.

[0043] Figure 10 is a perspective front three-quarter view of the trailer of Figure 8 with zero roll angle.

[0044] Figure 11 is a perspective front three-quarter view of the suspension arrangement of the trailer of Figure 10.

[0045] Figure 12 is a perspective front three-quarter view of the trailer of Figure 8 rolling to the left.

[0046] Figure 13 is a perspective front three-quarter view of the suspension arrangement of the trailer of Figure 12.

[0047] Figure 14 is a schematic view of a hydraulic arrangement of at least one embodiment of the present invention.

[0048] Figure 15 is a schematic view of a combined hydraulic and electromechanical arrangement of at least one embodiment of the present invention.

[0049] Figure 16 is a control flow diagram of a possible control of at least one embodiment of the present invention.

[0050] Figure 17 is a schematic view of a portion of a possible control of at least one embodiment of the present invention.

[0051] Figure 18 is a diagrammatic representation of an alternative support means of at least one embodiment of the present invention.

[0052] Figure 19 is a diagrammatic representation of another alternative support means of at least one embodiment of the present invention.

[0053] Figure 20 is a diagrammatic representation of another alternative support means of at least one embodiment of the present invention.

[0054] Figure 21 is a diagrammatic representation of an alternative undercarriage roll adjustment arrangement of at least one embodiment of the present invention.

[0055] In the drawings, like or equivalent features are allocated like reference numerals.DESCRIPTION OF PREFERRED EMBODIMENT(S)

[0056] Referring initially to Figure 1 , there is shown a schematic diagram of a trailer 1 . The trailer has a suspension arrangement 2 including the load support member or frame 3 for supporting the load 6. The load support member or frame 3 is pivotally connected to the undercarriage 7 by the roll pivot 8 which has a roll pivot axis 9.

[0057] Left wheel 11 is connected to the undercarriage 7 by a left suspension arm 21 such as the shown radius arm 27 or other suitable wheel locating geometry of which there are many known types. Left support means 31 is mounted between the undercarriage 7 and the left suspension arm 21 such that it extends as the left wheel 11 drops relative to the undercarriage and compresses or contracts as the left wheel moves upwards relative to the undercarriage as shown in Figure 2.

[0058] Similarly, right wheel 15 is connected to the undercarriage 7 by a right suspension arm 25 such as the shown radius arm 27 or other suitable wheel locating geometry. Right support means 35 is mounted between the undercarriage 7 and the right suspension arm 25 such that it extends as the right wheel 15 drops relative to the undercarriage as shown in Figure 2 and compresses as the right wheel moves upwards relative to the undercarriage.

[0059] One advantage of the radius arm or radius rod is that as the undercarriage is rolled into a turn, the wheels lean into the turn, i.e. the outside wheel gains negative camber and the camber of the inside wheel is increased. So, for a simple, easy to package wheel location geometry, the radius arm or radius rod maintains the wheels vertical relative to the undercarriage, resulting in wheels that have zerocamber when the undercarriage is level, then negative camber (relative to ground) for the wheel on the outside of a turn and positive camber (relative to ground) for wheels on the inside of a turn.

[0060] Frame roll adjuster 41 is mounted between the undercarriage 7 and the load support member or frame 3 such that as the frame roll adjuster is contracted as shown in Figure 2, the load support member or frame 3 and the load 6 rolls to the left about the roll pivot axis 9, that is the left side of the load support member or frame 3 and the load 6 move closer towards the undercarriage. Similarly, as the frame roll adjuster is extended, the load support member or frame 3 and the load 6 rolls to the right about the roll pivot axis 9, that is the right side of the load support member or frame 3 and the load 6 move closer towards the undercarriage.

[0061] The frame roll adjuster 41 can be situated on the opposite side of the trailer, in which case extension of the frame roll adjuster would roll the load to the left and contraction of the frame roll adjuster would roll the load to the right. Alternatively, a left and a right single-acting frame roll adjuster ram (not shown) can be mounted on the respective left or right side of the suspension arrangement.

[0062] The slave roll ram 46 can be provided so that the roll angle ‘a’ shown in Figure 2 of the support member or frame 3 relative to the undercarriage can be related to the roll angle ‘P’ of the undercarriage 7 relative to the ground 5. The roll angle ‘9’ of the suspension arrangement is the total roll angle of the load 6 or the load support member or frame 3 relative to the ground 5.

[0063] As the frame roll adjuster 41 drives rotation of the load support member or frame 3 relative to the undercarriage 7 about roll pivot axis 9 through roll pivot 8, the slave roll ram 46 is driven.

[0064] In Figure 1 , the slave roll ram 46 is located towards the right side of the trailer, so extends during a roll motion to the left and compresses during a roll motion to the right. Therefore, in Figure 1 the left roll slave chamber 47 is the rebound chamber of the slave roll ram 46, and the right roll slave chamber 48 is the compression chamber of the slave roll ram.

[0065] However, in Figure 2, the slave roll ram 46 is located towards the left side of the trailer. In this case, the slave roll ram compresses during a roll motion to the left and extends during a roll motion to the right. Therefore, in Figure 2 the left roll slave chamber 47 is the compression chamber of the slave roll ram 46, and the right roll slave chamber 48 is the rebound chamber of the slave roll ram. When the slave roll ram 46 is located on the same side of the trailer as the frame roll adjuster 41 , the slave roll ram 46 can be in parallel with the frame roll adjuster 41 , or as shown in Figure 2, the slave roll ram 46 and the frame roll adjuster 41 can be located at different lateral distances from the roll pivot axis 9.

[0066] In Figure 3 the one double-acting slave roll ram is replaced with two singleacting slave roll rams 46. The left single-acting slave roll ram 49 located towards the left side of the trailer compresses during a roll motion to the left, so its compression chamber is the left roll slave chamber 47. The right single-acting slave roll ram 50 located towards the right side of the trailer compresses during a roll motion to the right, so its compression chamber is the right roll slave chamber 48.

[0067] It should be noted that the frame roll adjuster 41 can be any form of actuator, so although it is shown as a double-acting fluid ram in Figures 1 , 2 and 3, it too can be two single-acting fluid rams, one located on each side of the trailer. The frame roll adjuster can also be a linear actuator such as an electro-magnetic ram.

[0068] Figure 4 shows an example of a trailer 1 of the present invention, in the form of a horse float, viewed from the underside to display the suspension arrangement 2. The load (not shown) that is loaded into or onto the trailer for potential transportation to and unloading at a destination, would in this example, be at least one horse. The load support member or frame 3 is supporting or part of the horsebox 56. For example, the horsebox can form the load support member or frame. Often horses are transported in pairs, so the horsebox can potentially accommodate multiple horses. The hitch 57 for connecting the trailer 1 to a towing vehicle (not shown) is connected to the drawbar 58 which is fixed to the horsebox 56.

[0069] The suspension arrangement 2 of the trailer 1 or horse-float in Figure 4 corresponds to the schematic suspension arrangement shown in Figure 2. Mudguards 59 are connected to the undercarriage?, the wheels 11 , 12, 15, 16 moving relative to the undercarriage 7. The load support member or frame 3 and the horsebox 59 are rotatably connected to the undercarriage 7 by the roll pivot 8. However, the left wheel is now first and second left wheels 11 , 12 and the right wheel is now first and second right wheels 15, 16. The left suspension arm is therefore now a first left suspension arm 21 for the first left wheel 11 and a second left suspension arm 22 for the second left wheel 12.

[0070] The suspension arrangement of Figure 5 is shown viewed from above in Figure 5. The rest of the horse float is omitted, as if the first right wheel, to allow the other suspension arrangement components to be seen. The first and second left wheels 11 , 12 are located by respective first or second left suspension arms 21 , 22.

[0071] Respective first or second left support means 31 , 32 are mounted between the undercarriage 7 and the respective first or second suspension arms 21 , 22. Similarly on the right side of the suspension arrangement, respective first or second right support means 35, 36 are mounted between the undercarriage 7 and the respective first or second suspension arms 25, 26.

[0072] The frame roll adjuster 41 is provided between the undercarriage 7 and a bracket that is part of the load support member or frame 3, to adjust the roll rotation about the roll pivot 8 of the load support member or frame 3 relative to the undercarriage 7. The slave roll ram 46 is adjacent to and in parallel with the frame roll adjuster, being also connected between the undercarriage 7 and a bracket that is part of the load support member or frame 3.

[0073] Figure 6 shows the horsebox 56 in the same orientation as Figure 4 but without the suspension arrangement. The suspension arrangement 2 including the load support member or frame 3 are shown in the same orientation in Figure 7.

[0074] Figure 8 shows the horse-float example of the trailer 1 from Figures 4 to 7 from a front three-quarter view. The trailer 1 is rolled to its right-hand side to roll into a right turn. As the horsebox 56 obscures most of the suspension arrangement 2 inFigure 8, the suspension arrangement 2 is shown alone in the same orientation in Figure 9 in the right roll position.

[0075] The undercarriage 7 including the mudguards 59 is rolled to the right relative to the wheels 11 , 12, 15, 16 and ground (not shown). The first and second left support means 31 , 32 have extended and the first and second left suspension arms (21 and not shown) have rotated downwards relative to the undercarriage 7. The first and second right support means (not shown) have contracted or compressed and the first and second right suspension arms (not shown) have rotated upwards relative to the undercarriage 7. The load support member or frame 3 is rolled to the right relative to the undercarriage 7 and mudguards 59. The frame roll adjuster 41 has extended as it is on the left-hand side of the vehicle. Similarly, the slave roll ram 46 in parallel with the frame roll adjuster 41 has extended.

[0076] Figure 10 shows the same horse-float example of the trailer 1 of Figure 8 from the same front three-quarter view, but in a zero-roll angle position. As the horsebox 56 obscures most of the suspension arrangement 2 in Figure 10, the suspension arrangement 2 is shown alone in the same orientation in Figure 11 in the same zero roll angle position.

[0077] The undercarriage 7 including the mudguards 59 is not rolled relative to the wheels 11 , 12, 15, 16 and ground (not shown), so the vertical gap between the left wheels 11 , 12 and the guard 59 on the left side of the suspension arrangement is the same as the vertical gap between the right wheels 15, 16 and the guard 59 on the right side of the suspension arrangement. The first and second left support means 31 , 32 and the first and second right support means (not shown) are in a neutral or ride height position, as are the first left suspension arm 21 and the second left, first right and second right suspension arms (not shown). The load support member or frame 3 is level relative to the undercarriage 7 and mudguards 59. The frame roll adjuster 41 is in a neutral position which is preferably at or near a mid-stroke position. Similarly, the slave roll ram 46 in parallel with the frame roll adjuster 41 in in a neutral position, which is again preferably at or near a mid-stroke position.

[0078] Figure 12 shows the same horse-float example of the trailer 1 of Figures 8 and 10 from the same front three-quarter view but rolled to its left-hand side to roll into a left turn. As the horsebox 56 obscures some of the suspension arrangement 2 in Figure 12, the suspension arrangement 2 is shown alone in the same orientation in Figure 13 in the right roll position.

[0079] The undercarriage 7 including the mudguards 59 is rolled to the left relative to the wheels 11 , 12, 15, 16 and ground (not shown). The first and second left support means 31 , 32 have contracted or compressed and the first and second left suspension arms 21 , 22 have rotated upwards relative to the undercarriage 7. The first and second right support means (not shown) have extended and the first and second right suspension arms (not shown) have rotated downwards relative to the undercarriage 7. The load support member or frame 3 is rolled to the left relative to the undercarriage 7 and mudguards 59. The frame roll adjuster 41 has contracted or compressed as it is on the left-hand side of the vehicle. Similarly, the slave roll ram 46 in parallel with the frame roll adjuster 41 has contracted or compressed.

[0080] The hydraulic schematic of Figure 14 shows the preferred arrangement of the support means 31 , 32, 35, 36. In this example, each of the respective first left, second left, first right and second right support means 31 , 32, 35, 36 is a respective double-acting support ram including a respective support compression chamber 61 , 62, 65, 66, and a respective support rebound chamber 71 , 72, 75, 76. In Figure 14, the slave roll ram 46 in on the left side of the trailer as shown in Figure 2.

[0081] The first left support compression chamber 61 , the second left support compression chamber 62, the first right support rebound chamber 75 and the second right support rebound chamber 76 are connected by the left support compression conduit 77a, the right support rebound conduit 78b and the first cross-connecting conduit 79 to form the left support compression volume 81 . The first right support compression chamber 65, the second right support compression chamber 65, the first left support rebound chamber 71 and the second left support rebound chamber 72 are connected by the right support compression conduit 78a, the left supportrebound conduit 77b and the second cross-connecting conduit 80 to form the right support compression volume 82.

[0082] Left support accumulator 83 is connected to the left support compression volume 81 to provide resilience to the left support compression volume. Right support accumulator 84 is connected to the right support compression volume 82 to provide resilience to the right support compression volume. The rod extending through the rebound chamber of each support means provides a larger effective piston area to the compression chambers than that of the rebound chambers. The lateral cross-connection of the support compression and rebound chambers with their differential effective piston areas and the resilience from the accumulators provides an arrangement having a higher roll stiffness than heave stiffness.

[0083] Flow into and / or out of the left support accumulator 83 and the right support accumulator 84 can be damped by providing a respective damper valve (not shown) between the respective accumulator and the respective compression volume. Additionally or alternatively, the support means can be individually damped by providing a respective damper valve between the respective support compression chamber and the respective support compression conduit and / or by providing a respective damper valve between the respective support rebound chamber and the respective support rebound conduit.

[0084] Damper valves are shown for both the compression and rebound chambers in Figure 14. So, the first left support compression damper valve 93a is shown between the first left support compression chamber 61 and the left support compression conduit 77a and the first left support rebound damper valve 93b is shown between the first left support rebound chamber 71 and the left support rebound conduit 77b. The second left support compression damper valve 94a is shown between the second left support compression chamber 62 and the left support compression conduit 77a and the second left support rebound damper valve 94b is shown between the second left support rebound chamber 72 and the left support rebound conduit 77b. The first right support compression damper valve 95a is shown between the first right support compression chamber 65 and the rightsupport compression conduit 78a and the first right support rebound damper valve 95b is shown between the first right support rebound chamber 75 and the right support rebound conduit 78b. The second right support compression damper valve 96a is shown between the second right support compression chamber 66 and the right support compression conduit 78a and the second right support rebound damper valve 96b is shown between the second right support rebound chamber 76 and the right support rebound conduit 78b.

[0085] The interconnection of the first and second left support compression chambers 61 , 62, the interconnection of the first and second right support compression chambers 65, 66, the interconnection of the first and second left support rebound chambers 71 , 72 and the interconnection of the first and second right support rebound chambers 75, 76 allows for free flow between the support means during pitch and warp motions of the trailer wheels relative to the undercarriage. So, the support means 31 , 32, 35, 36 arranged into the left and right support compression volumes 81 , 82 provide substantially zero pitch stiffness and substantially zero warp stiffness, while providing a higher roll stiffness than heave stiffness.

[0086] The fluid volume in the left and the right support compression volumes can vary, for example due to changes in load on the support means or due to temperature changes. Left support pressure transducer 85 can be used to monitor the pressure in the left support compression volume 81. Similarly, right support pressure transducer 86 can be used to monitor the pressure in the right support compression volume 82. While these pressure transducers are optional, they can be used to ensure correct operation of the suspension arrangement and to calculate the weight of the load carried by the trailer.

[0087] The variations in fluid volume can result in a change in height of the trailer, so each respective first left, second left, first right and second right support means 31 , 32, 35, 36 can include a respective first left, second left, first right or second right support position sensor 87, 88, 89, 90. A support fluid pressure supply arrangement 91 (or undercarriage levelling arrangement) including a fluid reservoir 92 is shown toprovide a source of pressurised fluid to the left support compression volume in (or up) valve 101 and to the left support compression volume in (or up) valve 102 and to provide a receiving reservoir for fluid released from the left support compression volume out (or down) valve 103 and to the left support compression volume out (or down) valve 104.

[0088] The support fluid pressure supply arrangement 91 is provided for maintenance of the height and roll attitude of the undercarriage by controlling the left and right heights of the undercarriage of the trailer. However, controlling the roll attitude of the undercarriage by driving the position of the left and right support means 31 , 32, 35, 36 while the trailer is in motion transporting a load, i.e. active control of the roll attitude of the undercarriage (which it should be understood is the same as active control of the left and right support means 31 , 32, 35, 36) requires larger flow rates and / or pressures.

[0089] While the left and right support means 31 , 32, 35, 36 can be controlled separately from the roll of the load support member or frame relative to the undercarriage, as one significant benefit of the present invention is to split the roll angle of the load support member or frame relative to ground into two components, being firstly a roll angle of the load support member or frame relative to the undercarriage and secondly a roll angle of the undercarriage relative to ground (or the average of the left wheels versus the average of the right wheels).

[0090] Using the slave roll ram 46 between the load support member or frame and the undercarriage and connecting left and right roll slave chambers to the appropriate left or right support compression volume can provide a direct relation between the roll angle of the load support member or frame relative to the undercarriage and the roll angle of the undercarriage relative to ground. This slave roll ram 46 and the connections to the left and right support compression volumes 81 , 82 by the left roll conduit 97 and the right roll conduit 98 effectively form an undercarriage roll adjustment arrangement 99. Then by actively controlling the roll angle of the load support member or frame relative to the undercarriage using a frame roll adjuster 41 , both the first roll angle being the roll angle of the load supportmember or frame relative to the undercarriage (a in Figure 2) and the second roll angle, being the roll angle of the undercarriage relative to ground ([3 in Figure 2) are controlled simultaneously, in proportion and with control of only the frame roll adjuster 41 being required.

[0091] So, in Figure 14, the slave roll ram 46 is on the left side of the trailer and the left roll slave chamber 47, which will reduce in volume during a left roll into a left turn, is connected to the right support compression volume 82 by the left roll conduit 97, so that during a left turn, fluid from the left roll slave chamber 47 is transferred through left roll conduit 97 into the right support compression volume 82, providing an extension motion to the right support means 35, 37 and a compression motion to the left support means 31 , 32 rolling the undercarriage towards the left. Similarly, the right roll slave chamber 48, which will reduce in volume during a right turn, is connected to the left support compression volume 81 by the right roll conduit 98, so that during a right turn, fluid from the right roll slave chamber 48 is transferred through right roll conduit 98 into the left support compression volume 81 , providing an extension motion to the left support means 31 , 32 and a compression motion to the right support means 35, 37. This arrangement is the connectivity that would be used in the trailer shown in Figure 2 and in Figures 4 to 13. The slave roll ram 46, the left and right slave roll chambers 47, 48 and the left and right roll conduits 97, 98 form the undercarriage roll adjustment arrangement 99.

[0092] The position of the frame roll adjuster (or the roll angle of the load support member or frame relative to the undercarriage which is an equivalent measurement when scaled) is sensed by a frame roll adjuster position sensor 110, which can be used as an input into control of the frame roll adjuster 41 which can be driven by a frame roll adjuster fluid supply arrangement 111. When such a hydraulic type frame roll adjuster is used, the frame roll adjuster fluid supply arrangement can use its own reservoir or use the fluid reservoir 92 of the support fluid pressure supply arrangement 91 . The mechanical connection, via structures on the frame and structures on the undercarriage, ensure that adjustments made by the frame roll adjuster drive the undercarriage roll adjustment arrangement 99.

[0093] However, as shown in Figure 15, the frame roll adjuster 41 can be an electrical or electro-mechanical device such as a linear actuator. The hydraulic support means 31 , 32, 35, 36, slave roll ram 46, the support fluid pressure supply arrangement 91 and the left and right support compression volume in and out valves 101 , 102, 103, 104 are retained as the slave roll ram provides a robust function in controlling the roll angle of the load support member or frame relative to the undercarriage (a in Figure 2) in proportion to the roll angle of the undercarriage relative to ground ([3 in Figure 2).

[0094] A further advantage of controlling the fluid volumes in the left and right support compression volumes 81 , 82, is that the height of the trailer can be lowered. This can be beneficial for unloading the trailer because if the hitch remains fixed to the towing vehicle or otherwise supported at a height, lowering the trailer at the support means results in a lowering of the rear of the trailer. This lowering is amplified at the rear of the trailer due to the larger distance of the rear of the trailer from the hitch compared to the distance of the support means from the hitch. Such a lowering of the rear of the trailer can be highly beneficial, allowing any ramp to ground to be nearer horizontal relative to ground. For example, the lower the angle of the ramp, the easier it is to load and unload horses or low ground clearance vehicles. In order to provide increased travel for larger roll-in angles and heave travel for comfort, the load support member or frame is preferably higher than the frame of a conventional trailer when in transit, but the ability to lower the suspension to reduce the height of the rear of the trailer above ground when transferring loads into / onto or out / off the trailer can negate this height increase or even provide for easier loading and unloading than a conventional trailer.

[0095] In the control diagram in Figure 16, the inputs used to the required roll angle are trailer speed and trailer yaw rate. The trailer speed input 122 is provided by at least one trailer speed sensor 121 . Using more than one wheel speed sensor can allow average speed to be calculated between the wheels for example, or a difference between left and right wheel speeds can be used to calculate turning radius, yaw rate and / or lateral acceleration. Preferably, however, the trailer yaw rate input 124 is provided by a trailer yaw rate sensor 123. These two types of input(speed and yaw rate) can be used to generate a lateral acceleration of the trailer. Simply measuring lateral acceleration or even two vertically spaced lateral accelerations can be inaccurate as roll inputs such as single-wheel bumps provide unwanted lateral accelerations and damping the lateral acceleration input(s) to improve unwanted influences will reduce response time of the controller. Using at least a left and a right wheel speed can allow the wheel speeds to be averaged, can provide redundancy and can allow for additional turning radius calculations to be made if desired.

[0096] A look-up table 125 or a calculation based on speed and yaw rate and / or on lateral acceleration is then used to find a target roll angle. This can be a target roll angle of the load support member relative to ground, but in this example is a target frame roll adjuster position 126, which is related to the roll angle of the load support member or frame relative to the undercarriage.

[0097] The comparison 127 is made between the target frame roll adjuster position 126 and the actual frame roll adjuster position measurement 141 . This comparison is used by a controller (of a type such as a Proportional Integral Derivative or PID controller) to generate a signal for a motor controller 131 . The motor controller can use multiple inputs including feedback 136 from the motor to generate one or more control signals for the motor 137. The motor may directly drive the position of the frame roll adjuster 41. In this example, the motor drives a bi-directional hydraulic pump which in turn adjusts the position of the frame roll adjuster 41 .

[0098] The position of the frame roll adjuster is detected by the frame roll adjuster position sensor 110 to generate the frame roll adjuster position measurement 141 used in the comparison 127.

[0099] Figure 17 shows an example of how a Kalman filter 180 can be used to generate the trailer speed input 122 and the trailer yaw rate input 124 used in the control shown in Figure 16. The benefit of using more inputs together with a Kalman filter is that the control input signals required, in this case the trailer speed input 122 and the trailer yaw rate input 124, can ultimately be obtained with very low noise.

[0100] The vehicle speed sensor(s) 121 are shown as a trailer left wheel speed sensor 151 producing a trailer left wheel speed measurement 152 and as a trailer right wheel speed sensor 153 producing a trailer right wheel speed measurement 154. Where at least two left wheels and two right wheels are provided, while a single left wheel speed sensor can be used on one of the left wheels and a single right wheel speed sensor can be used on one of the right wheels, more wheel speed sensors can alternatively be provided.

[0101] A three-axis accelerometer 155 is provided comprising a trailer longitudinal acceleration sensor 156 producing a trailer longitudinal acceleration measurement 157, a trailer lateral acceleration sensor 158 producing a trailer lateral acceleration measurement 159 and a trailer vertical acceleration sensor 160 producing a trailer vertical acceleration measurement 161.

[0102] A three-axis gyroscope 162 is provided comprising a trailer roll rate sensor 163 producing a trailer roll rate measurement 164, a trailer pitch rate sensor 165 producing a trailer pitch rate measurement 166 and a trailer yaw rate sensor 123 producing a trailer yaw rate measurement 168.

[0103] Preferably the three-axis accelerometer is mounted to the trailer, so the measurements are oriented with respect to the trailer rather than absolute. Similarly, preferably the three-axis gyroscope is mounted to the trailer so that measurements are oriented with respect to the trailer. However, where a combined three-axis accelerometer and thee-axis gyroscope is used, the accelerations and rotation rates measurements output can be absolute (relative to the ground) rather than relative to the trailer.

[0104] The support position sensors 169 include at least the first left support position sensor 87 producing a first left support position measurement 171 and the first right support position sensor 89 producing a first right support position measurement 175. Preferably the support position sensors 169 additionally include the second left support position sensor 88 producing a second left support position measurement 173 and the second right support position sensor 90 producing a second right support position measurement 177.

[0105] Also shown is the frame roll adjuster position sensor 110 producing the frame roll adjuster position measurement 141 . Where more than one frame roll adjuster is provided, corresponding additional frame roll adjuster position sensors can be provided producing corresponding additional frame roll adjuster position measurements.

[0106] All the measurements are input into the Kalman filter 180, i.e. the left and right wheel speed measurements 152, 154, the trailer linear acceleration measurements 157, 159, 161 , the trailer rotational rate measurements 164, 166, 168, the support position measurements 171 , 173, 175, 177 and the frame roll adjuster position measurement 141 . As is known, a Kalman filter can use a series of measurements over time, predicting behaviour of the trailer with the aid of a physical model (in this case a dynamic model of the trailer), comparing the predicted behaviour to the (potentially noisy) measurements and then providing estimates of variables (in this case the trailer speed and yaw rate) that are lower noise and therefore more accurate for use in control. The estimates of the variables are updated after a subsequent measurement using a weighted average. The Kalman filter is typically a mean squared error minimiser, but other versions are also known and can be equally applicable.

[0107] The Kalman filter can provide the two inputs (trailer speed and yaw rate 122, 124) into the controller of Figure 16. Alternatively, the Kalman filter algorithm can include the functionality of the trailer roll controller or even include feedback from the motor and provide control of the motor of the at least one frame roll adjuster or otherwise provide control of the at least one frame roll adjuster where the frame roll adjuster does not specifically include a motor.

[0108] Wherever the term measurement is used, the measurement can be a signal indicative of a measurement, the signal needing conditioning, scaling and / or interpreting to provide an actual measurement. The controllers and / or Kalman filter do not necessarily need the actual measurement, but rather the signal indicative of a measurement.

[0109] One significant advantage of the control outlined in Figures 16 or 17 is that no control signals or inputs are required from the vehicle. So, no special sensors or connectors need to be fitted to a suitable towing vehicle. Conventional connectors with power and lights signals (running lights, indicators, reversing lights, brake lights and possibly fog lights) are sufficient for use of the trailer on the road. All the inputs for the roll-in control are preferably obtained on the trailer. Similarly, the power used to drive the control can be obtained from the trailer. This can be from a battery on the trailer that is topped up by the vehicle power connection, a trailer-mounted solar cell, a dynamo or other known charging device on one or more of the vehicle wheels. For example, if the trailer wheels have electrical brakes, they may be used for generating power when braking.

[0110] The frame roll adjuster 41 while shown as a linear electrical actuator or double-acting fluid ram can be any equivalent device. For example, the frame roll adjuster can be two laterally spaced single-acting fluid rams, one on either side of the roll pivot. Electro-mechanical versions of the frame roll adjuster can include electro-hydraulic actuators which can include self-contained motor, pump, tank and hydraulic cylinder.

[0111] Although the undercarriage roll adjustment arrangement of Figures 14 and 15 shows direct adjustment of the fluid volume within the support means, the undercarriage roll adjustment arrangement 99 can be provided by adjustable mounts 190 provided in series with or as part of the support means 3T as shown in Figures 18 to 20.

[0112] In Figure 18 a single support means 3T is shown including an adjustable mount 190 comprising an adjuster device 191 and a resilient portion 192. The adjuster device 191 is part of the undercarriage roll adjustment arrangement 99 and can be any form of adjuster including a linear actuator, an electro-mechanical actuator, electro-hydraulic actuator or a fluid ram. The resilient portion 192 of the adjustable mount is connected between the undercarriage (not shown) and the spring damper arrangement 194. While the spring damper arrangement shown in Figure 18 comprises a coil spring 195 and a damper (commonly known as a shockabsorber) 196, any known form of spring damper arrangement can be used including a hydraulic ram with a fluid pressure accumulator and damper valving between the two. A self-levelling type of resilient support such as a Nivomat ram may also be used as an alternative. A resilient mount 198 is shown at the opposite end of the spring damper arrangement 194 to the adjustable mount 190.

[0113] In Figure 19, the adjuster device 191 is shown between the resilient portion 192 of the adjustable mount and the body (not shown). This can improve the sensing of the position of the adjuster device 191 , but can lead to increased sideloading on the adjuster device 191 as the spring damper arrangement 194 rotates with suspension travel in use, out of alignment with the adjuster device which is fixed to the undercarriage.

[0114] Figure 20 shows the same adjustable mount 190 as in Figure 18, but the spring damper arrangement comprises an air spring 195’ in place of the coil spring. As in Figures 18 and 19, the respective adjustable mount 190 in Figure 20 can be provided for each respective support means present, the respective adjustable mounts together forming at least part of the undercarriage roll adjustment arrangement 99.

[0115] The use of an adjustable mount in series with a single spring as shown in Figures 18 to 20 provides the supports with the same roll stiffness as heave stiffness, whereas ideally, the roll stiffness is higher than the heave stiffness. Therefore, the geometry can include a roll stiffness, such as being a torsion or twist beam axle between left and right wheels, the axle rotating relative to the undercarriage in heave but providing a stiffness in roll. Alternatively, an anti-roll bar as used on most automobiles can be used. Preferably however, where separate roll stiffness is provided by a torsion beam or anti-roll bar for example, the adjustable mounts in series with the supports are not used and instead, the undercarriage roll adjustment arrangement takes the form of at least one adjustable mount between the undercarriage and the torsion beam or anti-roll bar as shown in Figure 21 .

[0116] In Figure 21 the anti-roll bar 200 has a lateral portion 201 , a left end portion 202 and a right end portion 203, each end portion being connected at a distal end toa respective left or right wheel assembly (not shown). The lateral portion 201 is mounted to the undercarriage (not shown) by an adjustable mount 190 and a fixed length mount 204 such as the drop link shown. The adjustable mount 190 forms at least part of the undercarriage roll adjustment arrangement 99.

[0117] Alternatively, providing an anti-roll bar including a roll adjustment as is also known from automobiles such as the linear cylinder and lever arrangement or the rotary actuator arrangements used in actively adjusted anti-roll bars in automobiles. In this case, the linear actuator and lever arrangements or the rotary actuator arrangement is the undercarriage roll adjuster arrangement. The undercarriage roll adjuster arrangements using anti-roll bars may be said to effectively be in parallel with the support means.

[0118] The undercarriage roll adjuster arrangements using anti-roll bars can by driven independently from the frame roll adjuster, in dependence on the frame roll adjuster, or by an interconnection to at least one slave roll ram.

[0119] The hitch can be fixed at least indirectly to the load support member or frame. For example, the hitch can be fixed in relation to the load support member through being fixed by the drawbar to a horsebox or other part of the load support member or frame. This means that the hitch must rotate with the load support frame which is the largest rotation angle of the trailer relative to the ground.

[0120] Alternatively, the hitch can be fixed at least indirectly to the undercarriage. For example, the hitch can be fixed to the undercarriage by the drawbar. In this way the rotation of the hitch will correspond to rotation of the undercarriage, so the rotation of the hitch relative to ground can be less than rotation of the load relative to ground, requiring less roll rotation between the hitch and the towing vehicle than if the hitch was fixed to the support member or frame.

[0121] The load can be anything such as one or more horses, a car, delicate instrumentation or machinery or a container. The horse or horses would be transported in a horsebox, so the load support frame could be a horsebox, or thehorsebox could be fixed to the load support member of the suspension arrangement as shown in many of the Figures of the present invention.

[0122] Horses can have difficulty when accelerations act on them in multiple directions such as when braking and turning at the same time. So, for example, braking increases the load on the front legs and decreases the load on the back legs the back legs of the horse, whereas cornering to the left reduces the load on the left legs and increases the load on the right legs of the horse to react the centrifugal force acting to the right in a left turn. To significantly reduce the effect on the horse of cornering, the difference between the change in left legs force versus the change in right legs force, the horsebox can be rolled into the turn with the ideal roll-in angle being determined by a “coordinated turn”.

[0123] In a coordinated turn, the line of action of the resultant of the centrifugal force (due to lateral acceleration during a turn) and the gravitational force acting on the horse should remain vertical relative to the horse. So, the horse box is rotated so that all cornering forces only produce an increase in the weight felt by the horse, which can be combined with braking with less detrimental effect on the horse. But a true coordinated turn requires large roll angles, i.e. 11+ degrees for only 0.2g lateral acceleration. The roll angle of the load vs ground is distributed to a first roll angle between frame and undercarriage and a second roll angle between undercarriage and wheels I ground.

[0124] Additionally, the roll angle of the box may be limited to less than a coordinated turn angle while still being rolled into a turn. For example, the roll angle of the box or load support frame may be controlled during operation to be a portion of the roll angle required for a coordinated turn, such as at least fifty percent or preferably at least seventy percent, or more preferably at least eighty-five percent and most preferably at least ninety percent of the roll angle required for a coordinated turn. Even then the roll angle can only be adjusted up to a predetermined roll angle due to travel limitations in the suspension arrangement, beyond which the horse will experience a lateral acceleration related to the incremental increase in lateral acceleration.

[0125] Alternatively, the roll angle of the box or load support frame can be controlled to an ideal coordinated turn up to a predetermined roll angle due to travel limitations in the suspension arrangement, beyond which the horse will experience a lateral acceleration related to the incremental increase in lateral acceleration.

[0126] The at least one roll slave ram 46, when it is one double-acting ram, can be a through-rod fluid ram to provide equal effective piston areas for the left roll slave chamber and the right roll slave chamber.

[0127] The support means and the slave roll ram can each be a respective fluid ram that is air or gas-filled, i.e. pneumatic, or can be liquid filled, i.e. hydraulic. The fluid can be a compressible fluid such as silicone or can be relatively incompressible such as oil.

[0128] The frame roll adjuster and the undercarriage roll adjustment arrangement can be mechanically interconnected using the slave ram arrangement for example. Alternatively, the frame roll adjuster and the undercarriage roll adjustment arrangement can be individually controlled, preferably by the trailer roll controller.

[0129] The trailer roll controller can include a Kalman filter able to output control signals for the frame roll adjuster and for the undercarriage roll adjustment arrangement.

[0130] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

[0131] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising”, where used, is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Claims

CLAIMS:1 . A suspension arrangement for a trailer, the trailer including: a load support member or frame for supporting a load; at least one left wheel and at least one right wheel; the at least one left wheel and at least one right wheel being connected to the load support member or frame by the suspension arrangement, wherein the suspension arrangement further includes: an undercarriage pivotally connected to the load support member or frame by a roll pivot having a pivot axis oriented or extending in at least a longitudinal direction, at least one left suspension arm to locate the at least one left wheel relative to the undercarriage and at least one right suspension arm to locate the at least one right wheel relative to the undercarriage; at least one left support means for at least partially supporting the undercarriage relative to the at least one left wheel and at least one right support means for supporting the undercarriage relative to the at least one right wheel.

2. A suspension arrangement for a trailer as claimed in claim 1 , wherein the suspension arrangement includes: at least one frame roll adjuster connected between the load support member or frame and the undercarriage to adjust a roll position of the load support member or frame relative to the undercarriage.

3. A suspension arrangement for a trailer as claimed in claim 2, wherein the at least one frame roll adjuster is controlled by a trailer roll controller.

4. A suspension arrangement for a trailer as claimed in claim 3, wherein a roll angle of the undercarriage relative to ground is adjusted by roll adjusting the at least one left support means and the at least one right support means, said roll adjustment of the support means being controlled by the trailer roll controller.

5. A suspension arrangement for a trailer as claimed in any of claims 3 and 4, wherein a roll angle of the undercarriage relative to ground is adjusted by roll adjusting the at least one left support means and the at least one right support means, said roll adjustment of the support means being driven by, or controlled at least in part in dependence on, the roll position of the load support member or frame relative to the undercarriage.

6. A suspension arrangement for a trailer as claimed in claim 4 or claim 5, wherein the roll adjustment of the support means includes at least one left support adjustable mount for effectively adjusting the length of the at least one left support means and includes at least one right support adjustable mount for effectively adjusting the length of the at least one right support means.

7. A suspension arrangement for a trailer as claimed in claim 3 wherein an anti-roll bar is provided between the at least one left wheel and the at least one right wheel, the anti-roll bar being rotatably mounted to the undercarriage to permit heave motion of the undercarriage relative to the at least one left and at least one right wheel whilst providing a resistance to roll motions of the undercarriage relative to the at least one left and at least one right wheel, an undercarriage roll adjuster being provided in, on or in series with the anti-roll bar to provide roll adjustment of the undercarriage controlled by the trailer roll controller.

8. A suspension arrangement for a trailer as claimed in claim 2 or as claimed in claim 3, wherein at least one slave roll ram is provided in parallel with the at least one frame roll adjuster, the at least one slave roll ram being connected between the load support member or frame and the undercarriage, the slave roll ram being driven by rotation of the load support member or frame relative to the undercarriage; the at least one slave roll ram including a left roll slave volume and a right roll slave volume; each respective at least one left and at least one right support means including a respective support compression chamber, the or each left supportcompression chamber forming a left support compression volume, the or each right support compression chamber forming a right support compression volume, the left roll slave volume being connected to the right support compression volume, the right roll slave volume being connected to the left support compression volume.

9. A suspension arrangement for a trailer as claimed in claim 8, wherein the respective left or right support means is a respective double-acting ram, the or each of the respective left double acting rams including the respective left support compression chamber and a respective left support rebound chamber; the or each of the respective right double acting rams including the respective right support compression chamber and a respective right support rebound chamber; the or each respective left support compression chamber and right support rebound chamber being interconnected forming the left support compression volume and the or each respective right support compression chamber and left support rebound chamber being interconnected forming the right support compression volume.

10. A suspension arrangement for a trailer as claimed in claims 8 or 9, wherein the at least one slave roll ram is in parallel with the frame roll adjuster.11 . A suspension arrangement for a trailer as claimed in any of claims 8 to 10, wherein the at least one slave roll ram is a double-acting slave ram including the left roll slave volume opposing the right roll slave volume.

12. A suspension arrangement for a trailer as claimed in any of claims 8 to 10, wherein the at least one slave roll ram is a single-acting left roll slave ram including the left roll slave volume and a single-acting right roll slave ram including the right roll slave volume.

13. A suspension arrangement for a trailer as claimed in any of claims 2 to 12, wherein the frame roll adjuster is a linear actuator, or an electro-mechanical actuatoror an electro-hydraulic actuator or two single-acting fluid actuators or one doubleacting fluid actuator.

14. A suspension arrangement as claimed in any preceding claim, wherein: the at least one left wheel is a first left wheel and a second left wheel longitudinally spaced from the first left wheel; the at least one right wheel is a first right wheel and a second right wheel longitudinally spaced from the first right wheel; the at least one left suspension arm including a first left suspension arm for at least partially locating the first left wheel relative to the undercarriage; and a second left suspension arm for at least partially locating the second left wheel relative to the undercarriage; the at least one right suspension arm including a first right suspension arm for at least partially locating the first right wheel relative to the undercarriage; and a second right suspension arm for at least partially locating the second right wheel relative to the undercarriage.

15. A suspension arrangement as claimed in claim 14 wherein: the at least one left support means comprises a first left support means connected between the first left suspension arm and the undercarriage, and a second left support means connected between the second left suspension arm and the undercarriage; the at least one right support means comprises a first right support means connected between the first right suspension arm and the undercarriage, and a second right support means connected between the second right suspension arm and the undercarriage.

16. A suspension arrangement as claimed in any preceding claim wherein the or each at least one left suspension arm and / or the or each at least one right suspension arm is a respective radius arm or radius rod.

17. A suspension arrangement as claimed in claim 16 wherein each respectivesupport means is connected between the respective suspension arm whereby motion of the suspension arm relative to the undercarriage corresponds to compression and / or extension of the respective support means.

18. A suspension arrangement as claimed in any preceding claim wherein the pivot axis of the roll pivot lies in a vertical longitudinal plane.

19. A suspension arrangement as claimed in claim 18 wherein the pivot axis of the roll pivot is substantially horizontal.

20. A suspension arrangement as claimed in claim 18 wherein the pivot axis of the roll pivot is inclined either upwards or downwards towards a front of the trailer.

21. A suspension arrangement as claimed in any preceding claim wherein the trailer includes a hitch for connection to a towing vehicle, the hitch being located on or relative to the load support member or frame.

22. A suspension arrangement as claimed in any of claims 1 to 20 wherein the trailer includes a hitch for connection to a towing vehicle, the hitch being located on or relative to the undercarriage.

23. A suspension arrangement as claimed in claim 1 wherein a roll attitude of the load support member or frame is controlled by a trailer roll controller, including: a trailer speed sensor or input, a trailer yaw rate sensor or input.

24. A suspension arrangement as claimed in claim 23 wherein the trailer roll controller additionally includes a frame roll adjuster position sensor.

25. A suspension arrangement as claimed in claim 23 or 24 wherein the trailer speed sensor or input includes at least one wheel speed sensor or at least one input for a wheel speed sensor.

Images