GB2359528A

GB2359528A - Chassis structure for a land vehicle

Info

Publication number: GB2359528A
Application number: GB0103732A
Authority: GB
Inventors: Charles Peter Henry Morgan; Christopher John Lawrence
Original assignee: MORGAN MOTOR Co Ltd
Current assignee: MORGAN MOTOR Co Ltd
Priority date: 2000-02-25
Filing date: 2001-02-15
Publication date: 2001-08-29
Anticipated expiration: 2021-02-15
Also published as: GB2359528B; DE10108034B4; GB0004349D0; GB0316715D0; DE10108034A1; GB0103732D0

Abstract

A land vehicle is disclosed which includes a chassis (100) having at least two interconnected sections (200, 300), a first section defining a forward end of the vehicle and the second section defining a more rearward part of the vehicle chassis. One section (100, 200) has portions (201, 202) that overlap corresponding portions (301, 302) of the other and connecting means are provided for connecting the two sections together in normal use. The connecting means may comprise one or more fastenings which break on impact to permit the two portions to slide relative to one another. A suspension assembly (400) is also disclosed which is adapted to support a road wheel of the vehicle. The assembly has an upper linkage (401) and a lower linkage (402) which support a wheel carrier (403) and a spring/damper assembly (408) is connected to both the upper and the lower linkages and is worked by both the suspension linkages (401, 402).

Description

2359528 1 IMPROVEMENTS RELATING TO VEHICLES This invention relates to

improvements in vehicles, more particularly land vehicles. It especially relates to a chassis structure for a land vehicle. It also relates to a suspension assembly for a land vehicle.

For many years vehicles have been produced which comprise a separate chassis onto which a passenger compartment is located. The role of the chassis is to support the major components or subassemblies that make up the complete vehicle, such as the engine, gearbox, suspension, bodywork etc. The passenger compartment is typically attached to the chassis through resilient rubber bushes. These help prevent shock being transmitted from the suspension through the chassis to the passenger compartment as well as isolating engine vibration from the passenger compartment.

Recent trends in vehicle design have moved away from providing a separate chassis. In an alternative arrangement, land vehicles have been produced which use a chassisless monocoque construction. In these vehicles there is no separate chassis. However, it is common to provide a sub frame which is attached to the monocoque and which supports the suspension and even a subframe to support the engine. These subframes help to isolate road shocks from the passengers.

To meet present safety legislation, particularly for crash protection of passengers, the chassis or monocoque needs to be designed in such a way as to absorb the energy of impact. Typically this is achieved by providing areas of the chassis or monocoque which are intended to collapse in a 2 controlled manner in the event of a crash. As the areas collapse energy is absorbed in deforming the material.

A problem with both conventional chassis and monocoque vehicles is that such collapse due to an accident often results in the vehicle being written off. To repair the vehicle a whole new monocoque or complete chassis may be needed. In most cases such a repair is uneconomical. At best, a section of the chassis must be cut away and a new section welded in place It is an object of one aspect of this invention to provide a vehicle having an improved structure for absorbing impacts.

It is an object of a further aspect of this invention to provide a vehicle having an improved structure that allows for more flexible vehicle design.

According to a first aspect the invention provides a land vehicle having a chassis which comprises at least two interconnected sections, a first section defining a forward end of the vehicle chassis and a second section defining a more rearward part of the vehicle chassis, one section having portions which are adapted to overlap corresponding portions of the other section, and connecting means for connecting the two sections together relative to one another during normal operation of the vehicle.

By providing a chassis having two sections which overlap and are secured together by connecting means, several advantages are readily realised.

Firstly, it is possible to adjust the length of the chassis to accommodate different size or styles or bodywork. In the past this has required a completely different set of chassis to be provided if more than one length of vehicle is to be built. In the present invention, the amount of overlap 1 3 may be varied to alter the length of the chassis during assembly before securing the two sections together with the connecting means.

Secondly, it is possible to provide for the two sections to displace relative to one another in the event of an impact. The two sections may be adapted to slide relative to one another in an impact.

The first section may therefore be connected to the second portion by one or more fastenings which are adapted to break or deform to permit relative movement of the two sections in the event of an impact.

The fastenings may comprise shear bolts. Alternatively, the fastenings may comprise adhesive joints which are adapted deliberately to fail above a preset force generated in an impact.

The fastenings are preferably releasable to permit separation of the two sections. This is advantageous as it allows one section to be easily replaced following an impact, of course, in an alternative the fastenings may not be releasable, and could be cut - away to allow separation of the two sections but this is less convenient.

The overlapping portions of the forward most section of chassis may comprise at least two elongate elements which are adapted to extend longitudinally at least partially along opposing sides of the chassis. The elongate elements may be received within respective channels define by the second rearmost section of chassis. They may be slidingly received to allow insertion into the channels on assembly as well as movement in an impact. Alternatively, the rearmost section may include rails which overlap channels defined by the front section.

4 The two elongate elements may be identical but opposite handed. They preferably do not extend completely along the whole length of the channels in the second section. They may extend along, say, 80% or less, or less than 90% of the length of the channels.

The channels in the second section may also be located towards the outside of the chassis to define part of the sills of the vehicle. Such a structure can be used to provide safety for passengers in the event of a side impact.

The channels may extend along substantially the entire length of the second section. The rails may be received within substantially the entire length of the channels.

To provide for movement between the first section and the second section in an impact the portions which overlap preferably extend substantially longitudinally of the chassis.

The second section of the chassis may comprise one or more folded panels which are shaped to define the side channels. They may also define the floorpan of a passenger compartment, side walls, rear underbody and at least part of a bulkhead for the vehicle. The panels may be fixed together after folding by adhesive, rivets or other fastening means. Some additional shaping after they are fixed together may be permitted.

The front section of the chassis may comprise two elongate rails which may extend from a front most portion of the vehicle in front of an engine to the second section. One or more transverse cross members may interconnect the elongate elements. The cross member or members may provide mounting points for the engine and/or a gearbox of the vehicle.

The first section may further include a second pair of elongate members or rails which are spaced apart on either side of the chassis. They may be substantially parallel to and above the first pair of elongate members. They may be connected at a rearmost end to a bulkhead defined by the second section of chassis. The other ends may extend forward of the engine. These may also provide supports for the engine.

The two elongate elements on each side may be connected to a respective vertical side panel. These panels holds the elements together and may form the sides of an engine compartment. The side panels may also provide a profiled support for one or more bodywork panels. Additional cross members may extend transversely to link the elements together and provide supports for the drive train andlor suspension of the vehicle.

It is most preferred that both the first section and the second section of chassis are made of aluminium. The elongate elements of the first section may comprise box-section aluminium elements. The second section may comprise sheets of aluminium. This produces a strong, light weight, recyclable vehicle. An aluminium intensive vehicle (AIV) can be produced using such a chassis.

Of course, the two sections could be produced from other materials as appropriate.

The vehicle may comprise a motor car, such as a two seater motor vehicle.

In accordance with a second aspect the invention provides a chassis 30 having at least first and second chassis sections which at least partially 6 overlap, the amount of overlap being adjustable during assembly of the chassis so as to alter the length of the chassis prior to securing the two sections together.

By providing such a chassis it is easy to cater for a range of bodystyles and engine sizes by varying the overlap during assembly.

After the amount of overlap has been set, fixing holes may be drilled through both the first and second sections, each hole accommodating a fastening to prevent relative movement of the two sections. Alternatively, the holes may be produced prior to overlapping the sections. A number of such holes may be produced on one section and at least one hole in the other section. Depending on the chosen overlap, different holes will overlap to receive the fasteners.

The chassis may have more than two sections if desired. However, it is preferred that only two sections are provided.

It will be appreciated that the chassis of the second aspect will provide the 20 chassis for a vehicle in accordance with the first aspect of the invention.

It is another object of the invention to provide a suspension assembly for a road vehicle.

In accordance with a third aspect the invention provides a suspension assembly for a land vehicle comprising a wheel carrier which is adapted to support a road wheel, upper and lower suspension linkage which are adapted to support the wheel carrier relative to the body of the vehicle so as to permit movement of the wheel carrier relative to the vehicle, and a spring/damper assembly which is adapted to control movement of the 7 wheel carrier, and is connected to both the upper and lower linkages so that the spring/damper assembly is worked by both suspension linkages.

In the prior art, it is known to provide a suspension assembly in which one end of the spring/damper assembly is worked by either the upper linkage (or arm) or lower Linkage (or arm) whilst the other end is fixed to the vehicle body or a sub frame. In the present invention, it is preferred that the spring/damper assembly is connected to the suspension arms so that on movement of the road wheel carrier in one direction (i.e. upwards) both the lower linkage and the upper linkage act to compress the spring/damper assembly. Thus, compared to a prior art arrangement in which only one linkage works the spring/damper assembly more compression can be achieved for a given wheel travel. This provides superior wheel control.

The upper linkage may comprise a wishbone or substantially v-shaped or ushaped arm. The lower linkage may also comprise a wishbone or substantially v-shaped or u-shaped arm. The two arms may be spaced apart one above the other to form a dual - wishbone suspension. The linkages may comprise welded tubular portions or may be forged or machined or pressed to form a single rigid component.

Each linkage may define a base portion at one end and a pair of spaced apart arms at the other defining three take off points. The take off point at the base may be pivotally connected to the wheel carrier. The take off points on the arms may connect to the vehicle body or a sub frame to allow the arm to rotate about an axis which passes through the take-off points of the two arms. This axis is preferably substantially horizontal and longitudinal substantially of the vehicle.

The arms may connect directly to the vehicle body or to a sub frame which is in turn attached to the vehicle body. This may be through rubber bushes or roller bearings or rose joints.

The lower linkage may be longer than the upper linkage. The axis about which the lower linkage rotates may therefore be spaced further from the wheel carrier than the axis of rotation of the upper linkage.

The spring/damper assembly may connect to the upper linkage and lower linkage at a point along the linkage spaced from the pivot axis of rotation of the linkages. Movement of the wheel carrier relative to the vehicle body therefore causes the linkage to act as a lever to work the spring/damper assembly.

The spring/damper assembly may be connected at a first end to a portion of the lower suspension linkage that is spaced between the axis of rotation of the linkage and the wheel carrier whilst the other end connects to a portion of the upper linkage which is spaced on the opposite side of the axis of rotation of the upper linkage away from the wheel carrier. The upper linkage may therefore have an extended portion that extends from the axis of rotation away from the wheel carrier to support the spring/damper assembly.

In both cases, the distance from spring/damper to the pivot axis relative to the distance from wheel carrier to the axis should be chosen to ensure the ratio of movement of the wheel carrier to movement of the spring/damper assembly is optimised for a particular vehicle.

9 The spring/damper assembly may comprise a spring which is located concentrically around a damper unit. Other arrangements are, of course, envisaged. Indeed, the spring and the damper may connect to the suspension arms at different locations if desired. Also, either the spring or the damper may be omitted if required.

The suspension assembly may be provided at the front or the rear of a vehicle for front or rear wheels.

In accordance with a fourth aspect, the invention provides a land vehicle which includes a suspension assembly according to the third aspect of the invention.

The land vehicle may include a rear axle driving two rear wheels. On each side of the vehicle, a suspension assembly according to the third aspect of the invention may be associated with each rear wheel.

The land vehicle may include a chassis in accordance with the second aspect of the invention.

The two suspension assemblies may be independent from each other in their operation.

There will now be described by way of example only, two embodiments of the present invention of which:

Figure 1 is a plan view of a first section of a chassis for a vehi in accordance with one aspect of the present invention; cle Figure 2 is a plan view of a second section of a chassis for a vehicle in accordance with the invention; Figure 3 is a side view of the first section of chassis illustrated in Figure 1; Figure 4 is a side view if the second section of chassis illustrated in Figure 2; Figure 5 is a side view of the two sections of Figures 1 to 4 when assembled to form a complete chassis; Figure 6 is a plan view of the complete chassis shown in Figure 5; Figure 7 is a front view of the chassis of Figures 5 and 6 of the accompanying drawings; Figure 8 is a rear view of the complete chassis; Figure 9 is an isometric view of an embodiment of a suspension assembly for a road vehicle in accordance with a further aspect of the present invention; Figure 10 is a front view (looking back along the vehicle) of the suspension assembly of Figure 9; Figure 11 is a plan view of the suspension assembly of Figure 9; and Figure 12 is an end view of the suspension assembly of Figure 9.

A chassis for a land vehicle in accordance with the invention is illustrated in Figures 6 to 8 of the accompanying drawings. Figures 5 to 8 show the chassis assembled prior to the addition of bodywork, drivetrain and suspension and other components. Figures 1 to 4 show the chassis in two sections during assembly. Where possible, the reference numerals are used to indicate identical components in the drawings to improve clarity.

As can best be seen in Figures 4 to 8 the chassis 100 is produced in two sections 200, 300 which when assembled overlap and are secured together to form the complete chassis.

A first (forwardmost) section 200 shown in Figures 1, 3, 5 and 6 comprises two main side rails 201, 202 which are spaced apart on opposing sides of the section 200 and extend longitudinally of the chassis. Two subsidiary side rails 203, 204 are also provided which again are provided on opposite sides of the section and extend longitudinally. Two vertically disposed longitudinal side panel portions 205, 206 are provided which connect the main rails and subsidiary rails on a respective side together with the subsidiary rails spaced vertically above the main rails. The rails 201, 202, 203, 204 are secured to the side panels 205, 206 by rivets as shown, although adhesive may be used to bond the rails to the panels.

First forwardmost ends 207, 208 of each of the main rails 201, 202 are interconnected by a transverse cross member 209 which again is held in place by rivets or could be held by adhesive.

12 Working backward along the main rails from the front most ends two further transverse cross members 210, 211 are provided which connect the rails together. Again the connection is made using rivets.

Additional cross-bracing is provided to hold the top edge of the side panels 205, 206 and the subsidiary rails in position relative to one another. This comprises a sheet or panel 212 which connect the forwardmost ends of the subsidiary rails together and provides a location point for a suspension turret.

Finally, to complete the front section, a vertical panel 213 (best seen in Figure 7) extends across the front of the first section set back from the forwardmost portion of the side panels 205, 206 to connect the frontmost end of the main rails to the side panels 205, 206 and the forwardmost upper cross bracing 212. This, together with the side panels (and the bulkhead formed by the second section) defines a compartment into which an engine can be located.

The side panels 205, 206, when viewed from the side, have a flat base 214 and a convex curved portion 215 starting at the front of the section and extending around to the top of the side panel. This defines the shape of an inner wheel arch. Openings in the side panel permit a steering linkage and other components such as brake lines to pass from the engine compartment into the wheel arch of the finished vehicle.

The side panels 205, 206 therefore extend forward of the front ends of the main rails and the subsidiary rails. In the event of a frontal impact, energy is therefore initially absorbed by deformation of the side panels 205, 206.

13 As can be seen in Figures 1 and 3 of the accompanying drawings, the main rails 201, 202 initially extend longitudinally of the first chassis section from its front most end. They then bend outwards slightly before continuing longitudinally towards the rear of the completed chassis. The subsidiary rails 203, 204 do not extend as far rearwards, and are not bent outwards to any extent. They do, however, bend upwards slightly towards their rearmost end.

Both the side panels 205, 206 and the rails 204, 202, 203, 204 are made of aluminium. The rails are aluminium box section, whilst the side panels are shaped sheet material. Of course, other material could be employed.

The second (rearmost) section 300 of the chassis is shown in Figures 2, 4, and 6. It is made entirely from sheets of aluminium material which are folded into predetermined shapes and secured to one another by rivets.

Again, adhesive could be used as an alternative.

The rearmost section 300 comprises two 'U-shaped side channels which extend from the front of the second section 300 towards the rear longitudinally of the vehicle chassis. The channels are arranged so that the open side of the channel faces downwards. The channels 301, 302 are at the outside edges of the second section and are so spaced apart that they can accommodate the rear facing portion of the main rails 201, 202 of the front section 200. These channels 301, 302 define inner sills of a passenger compartment and together with the main rails 201, 202 located therein provide protection in the event of a side impact.

Between the side channels 301, 302 sheets of material form two floor panels 303, 304 and a raised U-shaped central tunnel 305 which extends 14 longitudinally of the second section 300 to accommodate a gearbox and a propshaft.

At the rear of the second section 300 vertical panels are provided which extend upwards and backwards from the side channels 301, 302 to define rear inner wheel arches. A further cross panel 308 connects these panels together to provide structural rigidly and serves both to form the top of the rear wheel arches and act as a boot floor and seat back if required.

A bulkhead 310 is defined at the front of the second section. This essentially consists of vertical panels 311 that extend transversely across the second section at its front most end to form a firewall. Side panels connect the edges of the firewall to the side channels 301, 302 and help to define the final shape of the sides of the vehicle.

As for the first section 200, the second section 300 is made of aluminium, although as seen in the embodiment it is entirely made from folded sheets of aluminium alloy. Again, other materials could be used instead of aluminium or its alloys.

The complete assembled chassis can be seen in Figures 5 to 8 of the accompanying drawings.

Although not visible, the rearmost portion of the main rails 201, 202 is accommodated inside the side channels 301, 302 of the second portion 300. It is fixed in place by a number of bolts 304 that pass through the walls of the side channels into the main rails. The main rails actually extend along almost the entire length of the channels.

The subsidiary rails 203, 204 are fixed at their rearmost ends to the bulkhead 310 of the second section 300 of chassis. It is notable that both the main rails 201, 202 and subsidiary rails 203, 204 are secured towards the outermost edges of the chassis. This ensures that in the event of a severe front impact they are not pushed back into the passenger compartment.

The point at which the main rails 201, 202 are secured to the channels 301, 302 may be altered to allow the chassis length to be varied. This is simply achieved by overlapping more (or less) of the rails 201, 202 within the side channels 301, 302. The resultant change in length of the chassis enables different lengths and engine (andlor gearbox) to be accommodated.

A further advantage of the chassis illustrated in the accompanying drawings is that by connecting the first section 300 to the second section using a fixing, such as a shear bolt, that is intended to break under load, the first section 200 may be allowed to move backwards on impact towards the second portion to absorb energy. The fixings may allow a progressive resistance against movement so as to control energy and help to dissipate energy. In addition to providing for the front most portions of the rails to collapse to absorb energy this further increases the chassis safety levels. It also allows for simple repairs as the rear section 300 can be easily separated from the front section 200.

In the final assembled vehicle, a rear suspension may be provided which is mounted on a subframe that is in turn connected to the second chassis section, whilst a spaceframe of either wood or other material may be fixed to the chassis to support external bodywork.

16 The chassis illustrated in Figures 1 to 8 supports a rear suspension assembly 400 which forms a second aspect of the invention. An embodiment of such a suspension assembly 400 in accordance with the invention is illustrated in Figures 9 to 12 of the accompanying drawings. Whilst specifically for the chassis illustrated it could, of course, be readily applied to any other land vehicle.

Figure 9 is a perspective illustration of one half of a rear axle suspension set-up. Only the suspension assembly associated with a drivers side rear wheel is therefore illustrated. It will, of course, be readily understood that the assembly for the far-side rear wheel is simply a mirror image of that shown. Also, the suspension is shown without the presence of a roadwheel or the vehicle body to aid clarity. Other views of the assembly are provided in Figures 10 to 12 of the accompanying drawings.

The suspension assembly 400 as shown comprises of an upper suspension linkage or arm 401 and a lower suspension linkage or arm 402. Each arm is a substantially U-shape with the base of the U connecting to a wheel carrier 403 through a pivot 404, 405. The two ends of each of the arms respectively define two take-off points for connection to a vehicle subframe (or directly to the body). An axis X-X' and Y-Y' connecting the two take-off points defines the axis about which each of the suspension arms may rotate. The arms are made from welded tubular bar although they could in fact be forged or pressed from sheet material if required.

The lower arm is longer than the upper arm (or wishbone) and so the axis Y-Y' about which it rotates is both lower than and also inboard of the vehicle compared to the rotation axis X-X' of the upper arm. The connection from the arms 401, 402 to the wheel carrier 403 is such that at 17 rest the wheel carrier 403 is held vertically to support the road wheel (not shown) vertically. The difference in length of the arms 401, 402 help eliminate tilt of the wheel carrier 403 under deflection and helps keep the caster angle constant.

For increased rigidity, each arm includes a respective tubular cross beam which connects the two take off points of each arm, and the arms connect to the subframe through spherical joints (not shown). The axis of rotation therefore passes through each cross beam 406, 407.

A spring/damper assembly 408 is provided which connects at one end 409 to the upper arm 401 and at the other end 410 to the lower arm 402. The assembly 408 compares a spring 411 which is located concentrically around a damping strut 412. Movement of the ends 409, 410 of the assembly 408 together is resisted by the spring and movement of the ends is damped by fluid in a chamber of the damping strut 412. This provides for control of the suspension.

The lower end of the spring/damper assembly 408 connects to the lower arm at a point spaced between the axis Y-Y connecting the vehicle body (or subframe) take off points and the wheel carrier. It is actually closer to the rotation axis than the wheel carrier. The lower arm therefore acts as a lever so that when the wheel carrier moves up to absorb a bump in a surface the end of the spring/damper unit 408 also moves up but by a smaller distance.

The other end of the spring damper unit 408 connects to the upper arm at a point spaced from the axis X-X' connecting the vehicle body (or subframe) take off points opposed to the wheel carrier 403. In practice, this is achieved by extending a portion of the upper arm beyond the axis 18 and correcting the spring/damper to this extended portion. This can be clearly seen in Figure 10 of the accompanying drawings.

The upper arm 401 also acts as a lever so that in the case when the wheel carrier 403 moves upwards the top of the spring/damper assembly 408 actually moves in the opposite direction, i.e. downwards.

It can therefore be seen that both ends of the spring/damper assembly 408 are worked by the suspension arms. More compression can therefore be achieved for a given travel of the wheel carrier 403 when compared to prior art arrangements in which one end of the spring/damper assembly connects to the vehicle body.

The characteristics of the suspension assembly can be altered by varying the ratio of the distance between the pivot axis of the arms, the point of connection of the wheel carrier and the point of connection of the spring/damper assembly.

The arms 401, 302 connect to the vehicle body through a subframe (not shown) that is connected to the rear of the chassis. Resilient rubber or elastomer mountings can be used to isolate vibration caused by the movement of the subframe from the chassis and hence passengers.

However, since the spring damper assembly connects to the arms rather than the vehicle body an extremely comfortable ride has been found to be possible even at high wheel load rates.

It will, of course, be understood that the present invention is not limited to either of the embodiments illustrated in the drawings which simply serve to illustrate examples of assemblies within the scope of the invention.

19

Claims

1. A land vehicle having a chassis which comprises at least two interconnected sections, a first section defining a forward end of the vehicle chassis and a second section defining a more rearward part of the vehicle chassis, one section having portions which are adapted to overlap corresponding portions of the other section, and connecting means for connecting the two sections together relative to one another during normal operation of the vehicle.

A land vehicle according to claim 1 in which the two sections of chassis are adapted to slide relative to one another in an impact.

3. A land vehicle according to claim 2 in which the first section is connected to the second section by one or more fastenings which are adapted to break or deform to permit said relative movement of the two sections in the event of an impact.

4. A land vehicle according to claim 3 in which the fastenings are preferably releasable to permit separation of the two sections.

5. A land vehicle according to any preceding claim in which the overlapping portions of the forwardmost section of chassis comprise at least two elongate elements which are adapted to extend longitudinally at least partially along opposite sides of the chassis and are received within respective channels defined by the second rearmost section of chassis.

6. A land vehicle according to claim 5 in which the channels on the second section are located towards the outside of the chassis to define part of the sills of the vehicle.

7. A land vehicle according to claim 5 or claim 6 in which the channels extend along substantially the entire length of the second section and the rails may be received within substantially the entire length of the channels.

8. A land vehicle according to any one of claims 5 to 7 in which the second section of the chassis comprises one or more folded panels which are shaped to define the side channels, the floorpan of a passenger compartment, side walls, rear underbody and at least part of a bulkhead of the vehicle.

9. A land vehicle according to claim 8 in which the front section of the chassis comprises two elongate rails which extend from a frontmost portion of the vehicle in front of an engine to the second section and one or more transverse cross members which interconnect the elongate elements that provide mounting points for the engine andlor a gearbox of the vehicle.

10. A land vehicle according to any preceding claim in which the first section and second section of chassis are made of aluminium.

11. A land vehicle substantially as described herein with reference to and as illustrated in Figures 1 to 8 of the accompanying drawings.

A chassis having at least first and second chassis sections which at 30 least partially overlap, the amount of overlap being adjustable during 21 assembly of the chassis so as to alter the length of the chassis prior to securing the two sections together.

13.

A chassis substantially as described herein with reference to and as 5 illustrated in Figures 1 to 8 of the accompanying drawings.

14. A suspension assembly for a land vehicle comprising a wheel carrier which is adapted to support a road wheel, upper and lower suspension linkages which are adapted to support the wheel carrier relative to the body of the vehicle so as to permit movement of the wheel carrier relative to the vehicle, and a spring/damper assembly which is adapted to control movement of the wheel carrier, and is connected to both the upper and lower linkages so that the spring/damper assembly is worked by both suspension linkages.

15. A suspension assembly according to claim 14 in which the spring/damper assembly is connected to the suspension arms so that on movement of the road wheel carrier in one direction both the lower linkage and the upper linkage act to compress the spring/damper assembly.

16. A suspension assembly according to claim 14 or claim 15 in which the upper linkage comprises a wishbone or substantially v-shaped or u-shaped arm and the lower linkage comprises a wishbone or substantially v-shaped or u-shaped arm.

17. A suspension assembly according to claim 16 in which each linkage comprises a base portion at one end and a pair of spaced apart arms at the other defining three take off points, the take off point at the base being pivotally connected to the wheel carrier and the take off points on the 22 arms being connected to the vehicle body or a sub-frame to allow the arm to rotate about an axis which passes through the take-off points of the two arms.

18. A suspension assembly according to claim 17 in which the lower linkage is longer than the upper linkage and the axis about which the lower linkage rotates is spaced further from the wheel carrier than the axis of rotation of the upper linkage, and further in which the spring/damper assembly is connected to the upper linkage and lower linkage at a point along the linkage spaced from the pivot axis of rotation of the linkages.

19. A suspension assembly according to any one of claims 14 to 18 in which the spring/damper assembly is connected at a first end to a portion of the lower suspension linkage that is spaced between the axis of rotation of the linkage and the wheel carrier whilst the other end of the spring/damper assembly connects to a portion of the upper linkage which is spaced in the opposite side of the axis of rotation of the upper linkage to away from the wheel carrier.

20. A suspension assembly substantially as described herein with reference to and as illustrated in Figures 9 to 12 of the accompanying drawings.

21. A land vehicle including a suspension assembly according to any one of claims 14 to 20.