WO2006016195A1 - Vehicle wheel suspension system - Google Patents

Abstract

Wheel Suspension System for a four-wheel vehicle, whereby each side of the vehicle is raised independently of the other side. Concurrently, the leverage ratio of the suspension of each wheel is modified according to the currently selected vehicle side height. Each wheel of the vehicle is elastically linked to the other wheel on the same side of the vehicle, in such a manner that, whenever the suspension of one wheel is compressed, the suspension of the other one tends to expand. In a more sophisticated version, each wheel is additionally linked in an elastic fashion to the wheel located diagonally on the opposite side of the vehicle, in such a manner that, whenever the suspension of a wheel is compressed, the suspension of the diagonally opposite one tends to get compressed, too. Auxiliary arm levers located between the wheels and the corresponding elastic units modify the leverage ratio between wheels and elastic units, in conjunction with the current position of the suspension of each wheel.

Description

VEHICLE WHEEL SUSPENSION SYSTEM

The present invention concerns an original mechanism of elastic linkage between the suspension units of the wheels of a 4-wheel vehicle designed to compete in special off-road trials races. Such off-road terrain features locally great slope fluctuations, as well as extremely pronounced ground relief.

One of the aspects of the particular invention is its capacity to vary, selectively, the vehicle height on either of its sides, in order to achieve a safe passage over specific routes, without risking lateral overturning of the vehicle.

A second quality of the particular invention, attained via a geometrically unique linkage of the suspension units, is the capacity of the vehicle suspensions to behave as if they had "softer" coil springs on the raised side of the vehicle. And, correspondingly, as if they had "stiffer" coil springs on the lowered side of the vehicle.

A third property of the particular invention concerns the simultaneous increase of the available vertical "travel range" of the suspensions of the two wheels on the same vehicle side, when the specific side is raised to the degree chosen by the driver.

A fourth property concerns the capacity (applicable when the vehicle is raised above a certain degree) to restrict geometrically the travel distance of the suspensions on one or both vehicle sides, so that the vehicle may cross terrain with pronounced local rises.

All the above are accomplished by way, at first, of a mechanical, elastic linkage of the suspension of each pair of wheels located on the same side of the 4-wheel vehicle. The operating principle of this linkage (hereafter referred to as the primary linkage) originates in the technical level, and in effect whenever the suspension of a wheel is compressed, the suspension of the corresponding wheel on the same side tends to expand. A uniquely innovative aspect of this linkage (in contrast to the current technical level) is the usage of intermediate auxiliary arm levers in the elastic linkage arrangement of the wheels located on the same side, so as to achieve (during the compression stage of each wheel's suspension) great differentiations in the leverage ratio between wheel and suspension coil spring, as it will be described here below. The elastic linkage of the wheels on the same vehicle side, as described in the present invention, includes an utterly innovative method whereby the driver may alter, at will, the vehicle height from the ground. According to this section of the present invention, it is feasible to adjust the height of one side of the vehicle independently of the other side.

A part (although not inseparable) of the present invention is a supplementary, secondary arrangement of elastic linkage of the wheels, which acts in an auxiliary capacity to the primary one. Although the operational principle of this secondary arrangement is derived from the technical level, nevertheless, the specific application in the particular invention, as it will be illustrated here below, constitutes a true innovation that does not derive obviously from the technical level. The innovative version of this secondary arrangement is based on the use of auxiliary arm levers with the aim to achieve a specific mathematic function concerning the variation of leverage ratios between the diagonally placed vehicle wheels and an additional elastic unit, whenever the vehicle changes height and ground clearance at the driver's will.

According to this secondary arrangement, the wheels located diagonally opposite on the vehicle are elastically linked in pairs, in such a manner that whenever the suspension of a wheel is compressed, the suspension of the other one tends to compress as well.

A significant part of innovation is the concept by which the two elastic systems, primary and secondary, cooperate although their nature is, at first, counteractive against each other. In summary, the objective of the present invention is the creation of an innovative linkage arrangement between the suspensions of vehicle wheels, whereby the driver shall be able to selectively raise either side of the vehicle, while satisfying the following prerequisites: a) The linkage of the suspensions shall be exclusively mechanical, in order to prevent reduced reliability, as result of eventual malfunction of any hydraulic circuits or modules that might have comprised its vital components. b) The suspension on the raised side of the vehicle shall exert less resistance to downward movement (diving) of the vehicle body than the suspension of the non- raised side. In this fashion, further diving of the non-raised side of the vehicle is statistically prevented, and so is, consequently, avoided the probability of points on the non-raised side of the vehicle touching ground bumps when travelling over natural obstacles. c) The vertical adjustment of the vehicle height shall be achieved simultaneously for both wheels on each vehicle side and not for each wheel individually. Consequently, linkage arrangements are significantly simplified, reliability is increased and other important benefits emerge, as it will be detailed later on. d) Besides the selective raising of each vehicle side, it shall be possible to raise both sides of the vehicle at the same time, when negotiating high obstacles. e) The suspension of each one of the vehicle's four wheels is desirable to be based on at least one longitudinal arm (leading or trailing) in order to take full advantage of its ability to retain the wheel in vertical position when the vehicle body is in horizontal position, regardless of the transverse slope of the ground.

Definitions

The term "wheel suspension" or simply "suspension" shall hereafter mean the total of moving mechanical parts interposed between the wheel and the vehicle body, through which mechanical parts, each point of the wheel is forced to move within a predetermined geometric locus during its vertical (or "approximately vertical", depending on the type of suspension) motion, when the vehicle travels over ground irregularities.

The term "suspension compression" or "wheel compression" shall hereafter mean the vertical movement of the wheel (controlled by the suspension) during the vertical distance between the wheel centre and a stationary reference point on the vehicle body is reduced. The term "maximum compression" of the suspension shall mean the point beyond which the mechanical structure of the suspension or the peripheral components does not allow further upward movement of the suspension or wheel.

The terms "suspension expansion", "suspension extension", "wheel expansion", "wheel extension" shall hereafter mean the reverse of compression movement, hence the suspension movement towards a direction which increases the vertical distance between the wheel centre and the vehicle body. The term "maximum extension" of the suspension or the wheel shall mean the point beyond which the mechanical structure of the suspension or the peripheral components does not allow further expansion of the suspension or wheel.

The term "suspension travel range" or "maximum suspension travel", or equally "maximum wheel travel", shall hereafter mean the length of line segment traced by the wheel centre between the positions of maximum compression and maximum extension of the wheel.

The term "elastic unit" of the suspension shall hereafter mean the elastic body (spring, rubber cone, torsion bar, etc.) through which a resistance force is developed against the compression movement of each wheel of the vehicle, such force being a mathematic function of the magnitude of the suspension compression during the wheel movement. The term "leverage ratio" (LR) between the wheel and the elastic unit, shall hereafter mean the ratio of the magnitude of wheel compression movement over the magnitude of the corresponding deformation of the elastic unit caused by the compression movement.

In most types of already established suspensions of the technical level, the leverage ratio of the wheel does not remain constant within the entire wheel travel range but, on the contrary, it varies continuously depending on the then current relative geometric position between the moving and stationary parts of the suspension. The type of suspension introduced by the present invention is not an exception to this rule. Therefore, each different point on the wheel travel is subject to different leverage ratio. If at a point of the wheel travel, any further upward movement (z) by a very small magnitude (Δz) results in increased deformation of the elastic unit by a very small magnitude (Δx), then the Instant Leverage Ratio (ILR) is hereafter defined by the formula ILR=Δz/Δx.

An obvious consequence of the previous definition is that a suspension exerts the greater resistance against "upward movement of the wheel-downward movement of vehicle body", or equally, behaves the more "stiffly" at any point of its travel, the smaller the magnitude of ILR is at that point.

Particular mention concerning the present invention should be made to the definition of the vehicle height, as it varies on one or both of its sides, according to the driver's will.

In a vehicle equipped with ordinary type of conventional suspension, the distance of each point of its body from the ground is unilaterally determined by the degree of compression of each spring in the corresponding wheel suspension. On the contrary, in a vehicle equipped with at least one integral elastic unit linking the wheels (such as the one to be revealed in the present invention), the degree of compression of the spring interposed between two wheels on the same side, is not enough to determine the permissible upward movement of each wheel separately.

Moreover, when the system of vehicle-suspension described herein is resting on a horizontal level ground, the increase of the height on one side does not necessarily entail an equal increase of extension on the corresponding two wheels on the same vehicle side. The magnitude of the resultant extension of the suspension of each wheel is determined, among others, by the then current value of the Instant Leverage Ratio of each wheel, vis-a-vis the integral elastic units of both primary and secondary elastic linkages with the remaining - mutually interactive - wheels of the vehicle, as will be described here below. Figure 32 depicts the left-hand side of the vehicle and, on it, the reference points S_LF and S_LR, front and rear respectively. The reference points are defined, in this case, as the points on the vehicle body with the least vertical distance from the centre of each wheel. For every partial adjustment of the vehicle side height with the vehicle resting on horizontal ground, we define as vehicle side Reference Height (Y_ref), the mean distance of points S_LF and S_LR from the ground. Therefore, as suggested by drawing 32,

Yref = (S_LFlF + S_LRIR) / 2

Where I_F and I_R, are the contact points of front and rear wheel, respectively, with the ground.

Known Technical Level

The elastic interlinking between front and rear wheels of a vehicle, through (in principle) an hydraulic arrangement, is part of the technical level already proposed quite some time ago, even with limited, at present, commercial applications, due to the questionable reliability of hydraulic systems, especially in "off-road" vehicles. One of the historically first proposals of elastic interlinking of front and rear wheels through hydraulic arrangement, is presented in US Patent 1647518 (Hawley) dating from 1923. The basic disadvantage of this arrangement is the insistence on, approximately, constant leverage ratios between the moving wheels and the elastic medium (which, in this case, is the air) throughout the entire wheel travel. Subsequent attempts at simulating the hydraulic interlinking of wheels through exclusively mechanical arrangements followed the same principle, failing to avoid the constant leverage ratios between wheels and elastic units. A typical arrangement is that described in US Patent 2099819 (Mercier), dating from 1934. In this case, an integral elastic unit forms a floating link with the suspension arms of the wheels on each vehicle end, thus is controlling the vehicle's nose and tail diving. Correspondingly, two longitudinal torsion bars, rotating in reverse direction to each other through a pair of gears, control the vehicle's inclination along the longitudinal axis, on each vehicle side. (The term "floating" suggests that both ends of each longitudinal elastic unit are linked to moving parts of the suspensions. In ordinary practice, on the other hand, one end of the elastic unit is linked to a moving part of the suspension mechanism, while the other end is articulated to a fixed point on the vehicle body.)

As can be observed by someone experienced in vehicle suspensions, the auxiliary arm levers to be revealed in the present invention are absent from the Mercier arrangement. As a result of this absence, the differentiation of the instant leverage ratio between points of full compression movement and full expansion of the suspension of each wheel is limited, a fact that does not facilitate fast vehicle travel over ground with pronounced surface fluctuations. Besides, the interlinking of longitudinal torsion bars through gears at a 1 :1 ratio, practically eradicates the differentiations in leverage ratios between the wheels on the same side. And it is evident that this kind of arrangement between wheels of the same vehicle end and the same vehicle side, does not allow the presence of an additional mechanism for selective rising or lowering of each vehicle side, as is the case with the present invention.

What has been stated above also applies to more recent proposals for mechanical interlinking of wheels, e.g. those described in US Patent 5839741 (Heyring). The multiple torsion bars of that mechanism are connected through gears at a 1:1 ratio. Obviously, the structure of this mechanism does not allow the selective differentiation of the height on each vehicle side, nor is it capable of increasing the leverage ratio of each wheel on the side that has been raised.

A very interesting application based on the Mercier technical level, is suggested by Lemaire through the document FR2453037. The main characteristic of this application is the usage of auxiliary arm levers in order to transfer the movement from the lever arms of the interconnected suspensions to a floating elastic unit built from a cone shaped elastomer material. A supplemental characteristic of this elastic unit is its "suspension" from the vehicle body through an oscillating arm, a fact which minimizes by one the degrees of freedom but doesn't remove the "floating" characteristic. From the review of the description and the drawings of this patent it is obvious that its inventor insisted a) on a linear relation between suspension movement and axial deformation of the rubber cone of the elastic unit and b) on a 1:1 ratio between the movement magnitude of each of the wheels compared to the other, when both wheels are in a distance from the ground under zero load. Characteristic are the linear mathematic functions that are presented by the inventor for the analysis of his linkage and the fact that the (apparently) second degree order of the function of the elastic unit resistance force (versus suspension movement), as it is presented in a diagram included in this document, derives from the linear compression of a rubber cone and not from the kinetic properties of the linkage synthesis.

Another application of the interconnected suspensions is described in FR2636570 (Stahl). Here, we have a floating unit which is connecting directly the two wheels of a prowled snow vehicle with eight wheels divided in two interconnected groups. A configuration like this adds a lot of inertia on the wheels due to the non-suspended mass of the elastic units. So, it is unacceptable for use in conventional four-wheeled, fast moving vehicles.

Another property of this linkage is its "physical instability" if it is used on a four- wheeled vehicle; when the suspension of one wheel is compressed to a certain amount the other interconnected wheel tends to extend to a comparatively lesser amount, causing a dive of the center of gravity and a deviation of the vehicle from its horizontal position. It is obvious, also, that during an increasing compression of the suspension of one wheel, this linkage causes the suspension to acquire an even more "softer" mechanical leverage in relation to the elastic unit. And, respectively, the extending suspension of the other interconnected wheel to become "harder", while, in a four-wheeled vehicle we need exactly the opposite. Another property of this certain interconnected suspension is its ability to vary the height of the vehicle. According to the description, the increase of the height may result either geometrically with the increase of the overall longitude of the elastic unit or dynamically by increasing the preload of the spring. In both cases, we have a reduction of the resilience of the suspension and of the maximum wheel travel due to the leverage changes that accompany the increase of the vehicle's height.

In our invention we achieve exactly the opposite which we consider more desirable for the purposes of the off-road motion.

In view of the foregoing, it becomes evident that our proposal, through the exclusive use of auxiliary arm levers (and a linking arrangement that causes magnitude-wise favourable changes to the leverage ratios), constitutes an innovation, although it partially takes advantage of known technical level elements. Furthermore, by combining auxiliary arm levers and "floating" linkage of a variable length elastic unit, it resolves successfully in a unique fashion the technical problem of selective fluctuation of a vehicle side height, which no-one had dealt with, so far. Types Of Suspension In Use

The most common choice of suspension system for off-road vehicles are the rigid axles, whose main feature is their ability to maintain the wheels of each axle constantly parallel to each other and perpendicular to the road surface.

A flaw of the rigid axles in vehicles taking part in off-road races becomes obvious when the mandatory route traverses a steep gradient slope. In that case the danger of the vehicle overturning becomes severe (fig. 1) when the vertical axis passing through the vehicle's gravity centre (CG) meets the ground outside the vehicle's footprint, defined by the contact points of the wheels with the ground.

The innovative solution chosen by the proponent of the present invention for the particular technical problem, was the addition of a mechanism for selective, temporary increase or decrease of the height of only one vehicle side, in order for the vehicle to remain approximately horizontal, regardless of the transverse ground slope. In this manner increased vehicle stability became possible, as shown graphically in fig. 2. Nevertheless, the particular solution could offer the maximum benefits if it could get rid of two drawbacks of the rigid axle. The first drawback is that due to the rigid axle, the distance between the tyre contact points with the ground remains fixed and equal to the wheelbase, regardless of the ground slope. The second is that the constant keeping of the wheels perpendicular to the sloping ground surfaces does not assist in maximising the tyre's available cross-section grip with the ground.

For all the above reasons, the optimum suggested implementation of the present invention was based, preferably, on a type of wheel suspension originating from the technical level, the main feature of which is that it maintains all four wheels constantly parallel to each other, when the vehicle moves straight. This suspension system is conventionally called "longitudinal arms suspension". These longitudinal arms are articulated onto an axle perpendicular to the vehicle's longitudinal axis and are classified into two types (as shown in fig. 3). When the articulation of such an arm (2) on the vehicle body (100) is located in front of the wheel (3) it is called a "trailing arm", whereas when the articulation (4) of the arm (5) is located behind the wheel (6) it is called a "leading arm". In this event the kingpin (9) around which rotates the front (steering) wheel when the vehicle changes direction, is permanently linked to the leading arm (5).

As a rule, the trailing arms suspend the rear wheels regardless if they are driving wheels or not. On the contrary, the leading arms suspend front wheels, but only if the latter are driving wheels. Fig. 4 depicts a special case of double trailing arms that has been used on front wheels of specific cars with rear wheel drive. In this case there are two trailing arms (5) for each wheel, the upper trailing arm and the lower trailing arm, at whose ends is articulated the kingpin (9) around which rotates each front wheel. The objective of this arrangement is to control the changes in caster angle of the kingpin in the entire travel range, by way of an articulated "4-link" mechanism. The form of this articulated quadrangle projected onto a plane longitudinal to the vehicle and perpendicular to the ground is graphically depicted in fig. 5. We observe that this quadrangle is composed of the active lengths of (7 and 8) of the two trailing arms, the kingpin (9) and the fixed distance, on the vehicle body, of articulations (11 and 12) of the two trailing arms, respectively. Angle α, formed between the projection of the kingpin (9) on the vertical longitudinal plane and the vertical axis, is the caster angle. The particular double trailing arm arrangement allows the control of the changes in the caster angle during the operation of the suspension, as opposed to the case of simple arms. In the latter case, as the kingpin is rigidly fixed to the arm, the caster angle changes equally with the angular movements of the arm.

Fig. 6 graphically depicts the behaviour of a vehicle equipped with an imaginary system for selective rising of one of its sides, similar to that of fig. 2, except that the rigid axle of fig. 2 has been here replaced by independent suspensions comprising longitudinal arms.

In this case the vehicle is extremely stable given that, when the body is horizontal, the axis of the vehicle's gravity centre passes exactly in the middle of the distance defined by the tyre contact points with the ground. Another favourable aspect of the specific suspension system is shown in fig. 7, where the magnitude of the transverse footprint length (FL) is clearly larger than the wheelbase (WB), thus providing greater vehicle stability when crossing inclined ground in a transverse direction to the slope.

Flexible Unit

The flexible element which in accordance with one of the feasible implementations under the present invention, has been selected from the technical level for the flexible support on either side of the vehicle and simultaneously for the flexible interconnection of the wheels on either side of the vehicle, is incorporated into the Common, Axially Flexible Unit, henceforth known as the CAFU. Through the CAFU, the suspensions for the two wheels of the same side of the vehicle are flexibly inter-connected in such a manner so that when the suspension of one wheel is compressed it tends to extend the suspension of the other wheel. Or equivalently when neither of the two wheels on the same side is touching the ground, then the forced upward motion of one wheel shall result in the downward motion of the other. The vehicle shall provide two CAFU, one on each side. One basic element of the specific CAFU, which constitutes an essential element in the structure of the present invention, is the fact that none of its sections are connected to a fixed point on the vehicle body but rather, its terminals, and only those, are connected with moving arm levers so that the spring in the CAFU shall be axially compressed simultaneously by both its terminals.

As it has already been mentioned, this manner of connection of a flexible unit to its environment defines the unit as "floating", in accordance with the prevailing terminology of the technical level. The selection of the "floating" connection for the flexible unit, in the specific implementation of the present invention, renders the CAFU not only as a simple bearer for the axially compressed spring, but it also provides it with the capacity to move in the space with multiple degrees of freedom so that it continually alters the momentary lever relations between the two wheels on the same side, to a pre-determined mutual interaction between them, as we shall see further on.

The major innovative element in the present invention, as it shall be subsequently revealed, is the method for the exploitation of the specific CAFU so that, through the monitored increase and decrease of its total length, the desired variation in the height of the vehicle shall be achieved with the simultaneous variation in the values of the momentary lever relations for the corresponding wheels. The increase and decrease in the length of the CAFU is achieved through a Length Adjusting Device, henceforth known as LAD, which is serially connected to the CAFU and is either incorporated in it or is outside of it. Figure 8 indicatively depicts the structure of a CAFU (15) which contains a cylindrical spring (16), that is axially compressed between two bearers (13, 14) that slide one against (and. inside) the other. Out of the two sliding CAFU bearers, one terminates at a joint (17) whilst the other contains the LAD (18) through which it is possible to regulate the distance between joints 17 and 20, in accordance with the desire of the operator. In the specific snap shot, the CAFU is schematically represented as being partially compressed due to the external forces that are applied to it. Its spring is also correspondingly compressed to the length ^.

The spring (16) has an available length I₀ >=li where I₁ is its length when the spring is installed into the CAFU (15) without subjecting it to an external compression load. This potential differentiation between the available length of the spring and its final length, after its installation into the CAFU, is due to the fact that the CAFU, as a result of its planned structure, is unable, after its assembly, to extend beyond a predetermined limit. Dependent upon this limit, in relation to the selected available length of the spring, shall determine whether the spring shall be pre-loaded or not, after its installation into the CAFU.

In accordance with the above it can be deduced that the proposed shape of the CAFU for the present invention may have the shape of a typical telescopic motor vehicle absorber, similar to those that are commercially available, where the spring is located in a co-axial position, under a pre-loading state. It follows that the specific CAFU shape is not the only one which may operate in accordance with the needs of the present implementation. Consequently, it may be replaced by whatever other shape with corresponding operation, without detracting from the essence of the present invention.

The manner in which the LAD in the CAFU alters its length (and accordingly the total length of the CAFU), may be whatever known method that is proposed by the existing technical level or that arises from it in an evident manner, without it limiting the scope for the implementations of the present invention. The requirement from such a mechanism is simplicity, credibility and especially the capacity to maintain its initially selected length, after its adjustment, regardless of the magnitude of the forces that are transmitted through it. There are indicatively mentioned two methods for the implementation of the mechanism both of which utilise an electric motor without also excluding the use of whatever other mechanical, electric-mechanical, electric-pneumatic or electric-hydraulic arrangement, which may arise in an evident manner from the technical level. In figures 9 and 10 is depicted a CAFU (15) of a structure that is similar to that of the typical telescopic absorber with the co-axially installed spring (16). The increase and decrease of its overall length is achieved through the rotation of the bolt (18a) by the electric motor (18b) in the LAD either directly or through a worm screw unit (18γ).

The previously mentioned individual applications are only presented as examples without excluding the capacity for developing from the present invention whatever other suitable system that may arise from the more general technical level. The adjustment of the LAD length, by the direct intervention of the driver, may be carried out, according to one version of the present invention, through an electric switch that is activated for as long as it is required until the completion of the process for the alteration of the LAD length by the corresponding mechanism. The specific switch may in another potential version of the present invention be, for example, hydraulic, where the differentiation in the LAD length is conducted through a hydraulic piston - even where this is not recommended, for reasons of reliability. In a more composite version of the present implementation, the intervention of the driver may be momentary and, simply, relate to the adjustment of the desired alteration by the switch. Thereafter the LAD is activated by comparing through a suitable sensor, its then momentary length to the final desired length, where it shall also be automatically immobilized. In more composite versions, the activation of the LAD may also occur without the intervention of the driver, through a development of the sensor signal which records the angle of the vehicle's tilt around the longitudinal axis and / or the implemented acceleration upon the transverse axis of the vehicle. Systems that permit, through suitable algorithms, the implementation of the previously mentioned scenarios for the activation of the LAD, are already known and belong to the technical level of the active and the semi-active vehicle suspensions.

As it was also previously mentioned in the introductory section of the present description, one additional advantage that defines the invention is the inherent capacity of the "floating" CAFU to alter, in accordance with the selected length of the LAD, the alteration function of the Instant Leverage Ratio of the wheels, for the entire range in the transposition of their suspension. In order to comprehensibly present the qualities of this "floating" arrangement on a series of an existing CAFU/LAD coupling, we shall initially consider that the auxiliary arm levers that suitably vary the performance of the suspension for the purpose of achieving the best possible result by that suspension are absent. In this case, we shall only rely on the presence of the main arm levers, which are located upon the suspension arms for each wheel. In due course, the presence and the qualities of the additional, auxiliary arm levers that constitute a section of the innovation of the present invention shall be revealed.

In figure 11 is indicatively depicted a simplified assembly of the flexible interconnecting suspension that constitutes the basis for the development of the elements that comprise the kinetic performance of the present invention.

In the vehicle of that specific illustration, the front wheels (6) are suspended by leading arms (5) that are housed in the corresponding joints (4) whilst the rear wheels (3) are suspended by trailing arms (2) that are housed in the corresponding, rear joints (1). A CAFU (15) intervenes between the suspensions on either side of the vehicle, in the specific example, that is joined at points 17 and 20 of the arm levers 105 and 102 correspondingly which shall henceforth be simply known as, "arm levers". The CAFU (15) carried on it one LAD (18) through which it is possible to increase the total distance between joints 17 and 20.

In figures 12 (a, b, c, d) are schematically depicted the mode for the operation of the flexible interconnection of the wheels on one side of the vehicle by the simplified partial implementation of one of the elements, in the present invention. In order to further simplify the drawings and the explanatory text, we shall consider that the front arm lever (105) forms a right angle with the leading arm (5) and that the rear arm lever (102) forms a right angle with the trailing arm(2).

Finally, and always for the purpose of simplifying the designs and explaining the principle for the operation of the invention, we shall assume that the active lengths of the front and the rear arm lever (105 and 102, correspondingly) are equal between themselves, as the active lengths of the leading and the trailing arm (5 and 2, correspondingly) are also equal between themselves. We shall determine as the active arm lever length the distance in the end joints of their terminals (17 and 20, correspondingly) from the joints around which these arm levers rotate (4 and 1 , correspondingly). We shall determine as the active leading lever length (R) the distance of joint 4 from the centre of the wheel, and correspondingly we shall also determine the length (R) of the trailing arm.

In figure 12a we have the case where the LAD (18) on one side has been adjusted at the minimum value of m = rrti and simultaneously both wheels on this side carry a null load, thus allowing the spring (16) to extend up to the maximum permissible length Ir The length I₁, in the specific CAFU example, has been pre¬ determined through the selection of the geometrical dimensions of the axial sliding bearers (13 and 14) and the selection of the relevant positions for the inhibitors (131 and 141) that are located upon the bearers 13 and 14, correspondingly, and which limit their motion in relation to the others.

In the case that is schematically described by figure 12a, the distance of the lower section of the body (100) of the vehicle from the ground is u_A. In figure 12b, where the adjustment of a length of the LAD (18) remains at the value m = m-i, there is schematically described the continuation in the state of figure 12a, when both wheels on the same side are equivalents loaded so that, correspondingly, their suspensions are equivalents loaded until the spring (16) is compressed to its minimum permissible length h- The further compression of the spring 16 is averted as a result of the "termination" in the motion of bearer 13, in the interior of bearer 14 without also limiting any other method for the limitation in the compression of the spring that may be proposed by the existing technical level.

Where, for the purpose of simplifying the explanations, we have accepted that the two wheels on this side have been equivalents compressed, it follows that the angular relocation of each of the longitudinal arms, leading and trailing (5 and 2, correspondingly), in relation to their initial position that was described in figure 12a, shall be equivalent to φ.

Consequently, the path that shall be followed by the centre of each wheel, from the initial position in figure 12a up to the final position in figure 12b, shall be equivalent to the length of the arc φ*R. Where, in figure 12b, u_B is the distance of the vehicle from the ground and we accept that the perpendicular relocation of the wheel, from the case in figure 12a to the case in figure 12b, is approximately equal to the length of the arc that was followed from the centre of the wheel, then we have the function:

UA - UB = φ*R

In figures 12c and 12d we have the corresponding cases to those in figures 12a and 12b however, now the LAD (18) is adjusted by the vehicle operator to its maximum length, m = Pi₂. In figure 12c we have the case of the complete extension of the suspensions and the wheels, under a null load and the admission that both wheels have been equivalents extended. In figure 12d we have the case where the suspensions of both wheels have been equivalents compressed, up to the point where the spring (16) has been compressed until its length reaches the minimum value of I₂.

Through a comparison of the cases in figures 12a and 12c it is apparent that further to an increase in the length of LAD by Δm = m₂ - Pn₁, the angular relocation of the longitudinal arms is equivalent to ω, when both the wheels are equivalents extended under a null load. Accordingly, the distance of this side of the vehicle from the ground, becomes uc and the difference uc - UA is approximately equivalent to ω^*R. Through a comparison of the cases in figures 12b and 12d it is apparent that further to an increase in the length of LAD by Δm = m₂ - mi, the distance on the side of the body (100) of the vehicle from the ground is increased by u_D - U_B for the complete compression of the spring (16) up to length I₂, as for case 12b. This applies, under the pre-condition for the equidistant compression of the suspensions on the same side. The difference UD - u_B is approximately equivalent to ψ*R.

In relation to the magnitude of the suspension paths, this increases, under certain pre-conditions, when the length of the LAD increases. The sum Ci for the angular relocations in the longitudinal arms of the wheels on the same side, where the spring is compressed from the initial length I₁ to the final length I₂ and where the LAD is adjusted at the value m-i, in accordance with figures 12a and 12b is: Ci = 2*φ The corresponding sum C₂, of the angular relocations in the longitudinal arms of the wheels on the same side, where the LAD is adjusted at the value m₂, in accordance with figures 12c and 12d is: C₂ = 2 (φ + ω - ψ)

The suitable selection of the total length of the CAFU as well as of the parameters mi and m₂ for the LAD must be conducted in such a manner where the angle ω (Figure 12c) to be substantially greater than the angle ψ (figure 12d). In this manner one of the requirements of the present invention is assured; and this requirement is that, as the value m in the adjustment of LAD increases, where mi < m <= m₂, there is a greater increase in the perpendicular path of the wheels on this side of the vehicle, in order for the spring (16) in the CAFU to bθ compressed from its initial length I₁ to its final length I₂.

An additional potential for the specific arrangement in figures 12c and 12d arises in the case where we continue to increase the value of m beyond the upper initial limit m₂. There is a value m = m_CR where m_CR > m₂ in relation to which the angles ψ and ω are equal. Accordingly, for every subsequent value m > m_CR, the angle ψ shall be rendered greater than ω. This implies that, as the LAD is adjusted at values constantly greater than the value m = m_CR, the specific side of the vehicle shall continue to be extended, whilst simultaneously, the range of the perpendicular relocation of the wheels which is determined by the terminal values I₁ and I₂ for the length of the CAFU spring shall be reduced.

This property is exceptionally useful during the passage of the vehicle through terrain with pronounced elevations, since, in this manner the minimum distance U_D is increased at a significantly greater degree than the distance u_c. In summary, from the moment that we adjust the LAD to the values m > ITI_CR, we gain the advantage in being able to increase the distance of the vehicle from the ground (u_D), when the wheels are under a full load, without requiring an equivalent elevation, with the danger of a significant reduction in stability, the initial height of the vehicle (u_c) when the wheels are load free. This property is best exploited, when the driver chooses to elevate, simultaneously, both sides of the vehicle, in order to travel over a large protrusion in the terrain which is located between the trails of his wheels.

Total Instant Leverage ratio It is apparent that in an arrangement such as that in figures 12 (a, b, c, d) the leverage ratio between one wheel and its corresponding CAFU spring is not stable throughout the range of the movement of the suspension for the said wheel. In fact, an essential element of the specific arrangement whose improvement is achieved through the present invention, is the multiple degrees of freedom that are incorporated in the continual alteration of the leverage ratio between the wheel and the spring, during the compression of the corresponding suspension due to the "floating" arrangement of the CAFU with the mechanisms that intervene between it and both wheels of the same side of the vehicle.

As we have characteristically seen in the simplified example of figures 12 (a, b, c, d), the increase in the length of LAD from mi to m₂, results in an increase of the travel of each of the wheels of the same side of the vehicle.

This implies that on each of these wheels an increase in the length of LAD results to an increase of its Instant Leverage Ratios in relation to the CAFU spring, and in fact for the whole of the wheel's travel or at least for a very large section thereof. Consequently it is evident that the alteration in the length of LAD results, in relation to the specific invention, to a source of an additional degree of freedom relative to the alteration of the Instant Leverage Ratios between the wheel and the spring in relation to the rate of the suspension compression or extension for the specific wheel.

In the simplified example of the figures (12 a, b, c, d) an assumption was made that the suspensions for both wheels on the same side were simultaneously and equivalently compressed between themselves. In reality, that certainly does not occur, due to the fact that each compression of the suspension on each wheel is dependent upon its corresponding instant load, which it is transmitted from the corresponding wheel, in conjunction with the Instant Leverage Ratio of the specific wheel in relation to the CAFU spring. It is however evident that the Instant Leverage Ratio of a wheel, in the present invention, is furthermore dependent also upon the instant position of the suspension of the other wheel, on the same side. In the simplified example at figure 13 (a, b) is schematically depicted the one side of a vehicle with the flexibly interconnected wheels of the same side, in accordance with the spirit of the present invention, and for one accepted, pre-selected, entire length of the CAFU.

In order to simplify the explanations, the LAD has been omitted and furthermore we shall consider that the suspensions of the wheels on this side are comprised of equal length longitudinal arms (5 and 2) in relation to the front and the rear wheel, correspondingly, to which arms there are steadily adapted, at a right angle, the equal length arm levers 105 and 102. Correspondingly, at the terminals (17 and 20) of the arm levers, is joined the axially compressed cylindrical spring (16), through which the two wheels are flexibly connected. In the case in figure 13a, we have the hypothetical case where the two suspensions have been loaded in such a manner so that when the longitudinal arms are in a parallel position with the longitudinal symmetrical axis of the vehicle body (100), each of the corresponding arm levers, 105 and 102, shall be located in a position that shall form a right angle to the axis for spring 16. In the situation in figure 13b we have precisely the same vehicle as that in figure 13a only now however the distribution of the loads onto the two wheels on the same side is different. In the specific hypothetical snap shot, the suspension of the rear wheel has been extended at the equivalent of the angular relocation ω of the corresponding longitudinal arm (2), always in comparison to the case in figure 13a. However, the front longitudinal arm (5) continues to be parallel to the implied longitudinal symmetrical axis of the body (100) of the vehicle. As we note, the angle that is now formed between the arm lever (105) for the front suspension and the axis of the spring (16), no longer forms a virtual right angle but an angle k < 90°.

It is apparent that despite the fact that the front longitudinal arm (5) continues to be located in the same relative position in relation to the body (100) of the vehicle, nevertheless, its Instant Leverage Ratio in relation to the spring has been altered, in comparison to that in figure 13a; and this occurs due to the fact that the instant position of the suspension of the rear wheel has altered in relation to the vehicle body.

Further to this, with the fact that the momentary position of the suspension for one wheel affects the Instant Leverage Ratio of the other wheel on the same side of the vehicle, we define that the Total Instant Leverage Ratio of a wheel is its Instant Leverage Ratio, when the suspension of the other wheel on the same side of the vehicle is fixed in a specific position.

Kinetics for flexibly interconnected same-side wheels

In whatever conventional vehicle that is equipped with suspensions at the already existing technical level and with the very use at or adjacent to the vehicle of the present invention, the limit for the complete extent of the suspension shall be determined by the corresponding limit for the extent of the telescopic hydraulic absorber which, in accordance with the rule, coexists with the flexible unit of the suspension for each wheel. Correspondingly, the limit for the maximum compression of the suspension is usually determined by the position of a flexible rubber-like cone which inhibits any further compression of the suspension and which cone is installed either between the vehicle body and the suspension or directly upon the telescopic hydraulic absorber, inhibiting its further compression beyond a pre determined limit. It is evident that in suspensions that are planned at this technical level, the maximum travel for the suspension of each wheel, is totally independent of the momentary position on any other wheel of the vehicle.

Conversely, in the case of the present invention, the parameter that determines the paths of the wheels is the individual lengths of the CAFU on each side both for its maximum compression as well as for its maximum extent. Through this admission it is evident that the maximum path of each wheel is dependent not only upon the momentary position of the other wheel on the same side but also upon the predetermined alterations in the leverage ratio for the suspension of the two wheels on the same side in relation to the CAFU. And as it has already been mentioned, one parameter for the alteration in the Leverage Ratios of the wheels on the same side is each adjustment in the height for the specific side of the vehicle, through the LAD.

In figures 14 (a, b, c) is schematically presented one arrangement for the leading arm and the trailing arm of the front and the rear wheel, correspondingly, on the same side of a vehicle, in accordance with a simplified implementation of the present invention.

The front leading arm is the side AOF of the front triangle ABO_F in figure 14a. This triangle rotates around the apex O_F, which apex is joined to a fixed point on the body (100) of the vehicle. The centre of the front wheel is adapted to the apex A of the previously mentioned rotating triangle.

The trailing arm is the side DO_R for the rear triangle CDOR in figure 14a. This triangle rotates around the apex O_R, which apex is joined to a fixed point on the vehicle body. The centre of the rear wheel is adapted to the apex D in the previously mentioned rotating triangle.

The sides BOF and CO_R of the front and the rear triangle, correspondingly, represent the arm levers of the front and the longitudinal arm, correspondingly, with the angles BO_FA and CORD having been selected at less than 90°. At the apexes B and C of the two triangles are joined the two terminals of one CAFU whose length, when it is at full extent, is equal to the distance BC. The length of this CAFU, at full compression, is equal to B'C, as it appears in the same figure. In figures 14b and 14c we have the relevant positions for the two triangles when these are rotated about the points O_F and OR, correspondingly, under the pre condition that the compression load of the CAFU spring does not exceed the force which it has been pre loaded, after its installation in the CAFU. Namely,

In interpreting the figures 14a and 14b we conclude that, with a fixed length of the CAFU, the specific joined rectangle OFBCO_R with the rotation points O_F an_d

OR, cannot be moved to the left beyond a limit which is dependent upon the geometry for the mechanism with the four joined rods, as there is no point, located within the circumference of the circle (O_R, ORC) that is located to the left of point Ci and whose distance from whatever point of the circle (OF_, O_FB) is equivalent to BC. Evidently, the points Ai and Di constitute the limits for the relocation of the apexes A and D, when the two arm levers O_FB and O_RD execute left turn angle relocation.

Correspondingly, by comparing the figures 14a and 14c, we conclude for the same previously mentioned reasons, that the points A₂ and D₂ constitute the limits for the relocation of the apexes A and D, when the arm levers of the mechanism execute right turn angle relocation.

In accordance with the above, we conclude that, in the previously mentioned mechanism, the maximum path that the front wheel may travel, without further compressing the CAFU spring, is determined from the length of the implied arc AiA₂ with the centre O_F. Correspondingly, the maximum path, under the same conditions, which the rear wheel may travel, is determined by the length of the implied arc D₁D₂ with the centre O_R.

From the moment however when the force through which the CAFU spring is compressed exceeds the value with which is has been pre loaded, it is evident that the mechanism in figure 14 may move in a range that is greater than that which has been pre determined by the previously mentioned limits.

So, where the arm lever O_RC is compelled to turn to the left, beyond the position ORC_I in figure 14b, the kinetic resistance that shall be exercised by the triangle ABO_E shall result in the compression of the CAFU spring. When the spring is compressed up to the maximum degree that is provided in the CAFU structure, the apex C shall have been relocated up to the position d^" in figure 14b and apex B shall have been relocated up to the position B₁' so that B₁Oi' = BC. Finally, apex A shall have been relocated up to the point

beyond which the mechanism is unable to kinetically proceed, to a further left turn angle relocation of the arm levers, whilst apex D shall result at position D₁ ^'.

Conversely, by moving the mechanism in a right turn as in figure 14c, the apexes A and D shall result at the positions A₂ ^'και D₂ ^', correspondingly, when the CAFU spring shall have undergone the maximum permissible compression. In accordance with the above it can be deduced that, in the specific form at figure 14, of the present invention, the maximum path that the centre of a wheel can theoretically travel, is equivalent to the length of the arc that the centre of the wheel records during its complete kinetic range for the operation of the specific mechanism, when the CAFU spring is at its maximum permissible compression. Accordingly, the maximum theoretical path for the front wheel shall be the arc Ai'A₂ ^' and for the rear, correspondingly, the arc Di^'D₂ ^".

The sequence of the relevant positions of points A and D during the movement of the corresponding arms, is schematically depicted, in figure 14d.

In accordance with the above, it is perceived that during the interconnection of the wheels on the same side, as it is described by the present invention, it is not necessary for both wheels to touch the ground in order for one of them to cause, through its suspension, a compression in the spring that is suspended relative to the load that it carries. The snap shots in figure 15 constitute a realistic figure of the movements of the wheels, corresponding to those of the group of figures at 14. From the moment when the front wheel leaves the ground, that side of the vehicle is supported upon the rear wheel (figure 15a) whose suspension compresses the spring as the rear wheel moves along the range of points between Di and D-T, in figure 14b.

When both wheels are in the air, under a null load, (figure 15b), the momentary positions of the wheels shall constitute a section in the arcs AiA₂ and D₁D₂, in figure 14c, for the front and the rear wheel correspondingly

Finally, when the front wheel encounters the ground (figure 15c) and for whatever period the rear wheel is in the air, we shall have a right turn angle relocation of the mechanism, similar to that which is described in figure 14c. The front wheels shall move, initially, from any position Ax (that is located lower than A₂) up to position A₂ without having caused in the meantime a compression in the spring. The compression of the spring shall commence from the moment when the compression of the front suspension exceeds point A₂ in a direction towards point A₂ ^'.

At this point is stressed an advantage in the mechanism of the present invention, where during the movement of the ascending wheel from any initial position up to position A₂, the suspension of the rear wheel extends up to position D₂, without the absorption of energy by the spring, thus permitting the speedier restoration of the ground contact of the rear wheel of the vehicle.

The maximum path that every wheel may separately travel, in the specific arrangement, is dependent in accordance with science, upon the momentary position of the other wheel on the same side. Accordingly the maximum range for the path of the front wheel in figure 14d is the arc AiA₂ ^', when the rear wheel is compelled to travel the arc D₂D₂ ^'. Conversely, the maximum range for the path of the rear wheel is D₂D₁ ^' when the front wheel is compelled to travel the arc A₁Ai^'.

In the case with flexible interconnected wheels on the same side, we hence forth determine as the Inactive Path for each wheel, its maximum possible path, when both this wheel and the other on the same side, are moving vertically, under a null load or under a load that is smaller than the one that may activate the compression in its CAFU pre loaded spring. In the example at figure 14d, the

Inactive Path for the front wheel is the space A₁A₂ and the rear, correspondingly, D₁D₂.

In a special uses vehicle, such as that which is referred to in the present invention, the meaning of the Inactive Path constitutes an exceptionally useful property whose exploitation, in the given circumstance, constitutes an innovation that is exclusively dependent upon the present invention, granted that it has never, been developed, up till now, at a technical level. During the jumping of the vehicle when it is travelling quickly over a ground with large protrusions, where for the time being, one or more wheels are not touching the ground, it is feasible, through the existence of the Inactive Path, to absorb large quantities of energy through the hydraulic absorbers that are installed between the suspension in the wheels and the vehicle body. The absorption of this kinetic energy by the suspension is achieved, initially, without a compression of the CAFU spring and this constitutes, for those that have experience in those types of applications, a significant advantage for the present invention. In a vehicle with conventional suspensions at the known technical level, the meaning of the Inactive Path is non existent, due to the fact that the perpendicular movement of the wheel, along the entire range for its up and down movement, it is always accompanied by alterations in the compression of the corresponding suspension spring.

In the case of the arrangement of the vehicles at 14 (a, b, c), we note that only within the intervals A₂A₂ ^' and DiD₁ ^', for the front and the rear wheel correspondingly, there are any alterations present in the compression of the CAFU spring, during the vertical relocation of a wheel, when the other wheel on the same side is not in contact with the ground.

Further to this, we determine as the Active Path (AP) for a wheel the interval that the centre of the wheel travels, during its compression, from the point of commencement of the CAFU spring compression, up to the point where the spring undergoes its maximum permissible compression under the pre condition that, throughout this whole interval, the other wheel on the same side of the vehicle, is either exercising minimal force on the ground or is not in contact with the ground. Accordingly, as the Average Active Leverage Ratio for a wheel (AALR) we hence forth determine the ratio of the length of the Active Path of the wheel in relation to the magnitude in the alteration of the length of the spring, from the initial length that it has when it is installed in the CAFU, up to its maximum permissible compression. Thus, where I₁ and I₂ is the initial and the final length of the spring when it is installed in the CAFU, then

AALR = AP / (I₁ - 1₂)

Considering with all that has been previously mentioned, an increase in the length of the LAD in accordance with the present invention, results in a simultaneous increase in the AP. Granted that the difference Δl = Ii - I₂ remains stable, it follows that an increase in the length of the LAD is accompanied by an increase in the AALR. This property constitutes an axiomatic element of the present invention. Progressive Interconnection

The main difference between the two arrangements illustrated in Fig. 13a and 14a respectively, is the angles formed between the elastic unit and each one of the corresponding lever arms. In Fig. 13a the magnitude of this angle is approximately equal to the right angle but, as we can see, the same angles are substantially smaller in Fig. 14a. In practice, there is a bigger difference to the behaviour of these two (almost similar) linkages if, for a moment, we suppose that the wheels of the vehicle in Fig. 13a are under null load.

Let us assume, now, that we have a vehicle with two interconnected wheels, as previously described. Let us assume, additionally, that we have the vehicle immobilized in such a manner that both of these interconnected wheels are not touching the ground and we are moving one of these two wheels from the full extension point to the point of full compression. Obviously, the other wheel will be moving to the opposite direction without any load transfer to or from the elastic unit which, under these circumstances, acts as a simple link.

Let us suppose that, at a certain point of their movement, the two (of equal length) lever arms (102, 105 of Fig. 13a) form, simultaneously, a right angle with the elastic unit (16). In such a case we will have the undesirable condition of an articulated parallelogram with the two lever arms moving with exactly the same angular displacement. And if the suspension amis have equal length, then the wheels will move in equal displacements in opposite directions.

Contrary to this presented situation, we are convinced that is absolutely beneficial to have a certain differentiation between the magnitude of the relative movements of the two connected wheels, especially when one of them is approaching its maximum compression point. In this case, there are many practical advantages if, for a small displacement of the wheel approaching its maximum compression point, the other wheel "responds" with an extension of bigger displacement.

The embodiment illustrated in Fig. 14a complies fully with this desirable condition due to the (much lesser than the right angle) magnitude of the angles formed between the elastic unit BC and each one of the arm levers O_FB and O_RC. In a situation similar to that previously described, with both of the interconnected wheels in a distance from the ground, the behaviour of the linkage of Fig 14a will be very different.

Firstly, there will be a point (hereinafter called "point of equalization") in the path of the opposite moving wheels where a very small displacement ΔZF of the front wheel will be practically equal to the displacement ΔZ_R (to the opposite direction) of the rear wheel. After this critical point of equalization, every small displacement of the wheel moving in the direction of compression causes a bigger magnitude of displacement for the wheel moving in the direction of extension.

Hereinafter, we call as "progressively interconnected" the two wheels of the same side of the vehicle which are linked via an elastic interconnecting linkage and this linkage has this specific property: "If both of the interconnected wheels are in the air, then there is a point in the path of each of the two wheels that beyond this, every displacement of the wheel moving in the direction of compression cause a displacement of bigger magnitude to the wheel which is moving in the direction of extension".

Complete form of the first half of the invention The simplified linkage in figures 12 (a, b, c, d) and 14 (a, b, c) relates to the comprehension of the operating principle for the present invention in both its core elements; the CAFU/LAD combination and the progressive interconnection. In fact, a more composite linkage is required between the wheels on the same side and the corresponding CAFU in order that the correlation in the altering Leverage Ratios between each of the two wheels and the CAFU to be as functional as possible, in accordance with the needs for the output of the vehicle suspension under its realistic operating conditions.

All the various indicative embodiments that will be presented hereinafter are following the concept of the linkage presented schematically in Fig. 14a and the progressive interconnection properties that it delivers. The deviation of the original linkage of Fig. 14a is forced either due space restrictions or due our need to benefit from only a pre-selected part of the whole Leverage Ratio Variation mathematical function it "produces". In certain circumstances, the partial deviation of the original linkage is preferred in favour of a modified mathematic function that is more compatible with our specific needs. Conclusively, all these aforementioned needs are forcing us to adapt more composite linkages than the original but without a deviation from its basic, "progressive" concept. One such example of a composite arrangement, in the spirit of the invention, is depicted in figure 16, where the auxiliary rotating arm levers are revealed (42, 43) which constitute an essential element of the present invention and which are determined as the rotating arms around a instant or fixed axis of the vehicle body and are interposed, in series, between the arm of the wheel suspension and the CAFU, which are connected to each other, either directly or indirectly. As it is apparent, the longitudinal arms 5 and 2 for the front and rear wheel correspondingly, are not directly connected to the CAFU (15). Conversely, the compression in the CAFU spring (16) is monitored by the rotating auxiliary arm levers (42, 43) that are joined to the vehicle body and which auxiliary arm levers are connected to the arms (5 and 2 correspondingly) of the wheel suspensions, through push-pull connecting rods (41 ). In this case, as in every other alternative assembly under the spirit of the present invention and arising from it, the definitions for the Active Path and the Average Active Leverage Ratio shall apply, for each wheel, as they have already been formulated in the cases of the simplified assemblies in figures 12 (a, b c d) and 14 (a, b, c).

In figure 17 is depicted an alternative form of the flexible interconnection of the wheels, in the spirit of the present invention. The front suspension is comprised of two trailing arms (5, 5A) whilst the rear suspension is comprised of a trailing arm (2) with its arm lever (102) installed in an inverted position in relation to the previous versions. The «floating» CAFU (15) is compressed on either side, by two auxiliary arm levers (42, 43) each of which is connected through push-pull rods (41 ) to the suspension of the corresponding wheel. In figure 18 is depicted another potential assembly which is based on the spirit of the present invention. Here, between the auxiliary arm levers (42, 43) only the CAFU spring (16) is extended. The LAD (18) is not in direct contact with the CAFU but continues to be connected to it in series, in order that the synthesis maintains all the properties that have already been mentioned.

In figure 19, the specific shape Inverted CAFU (15A) is connected to the suspension arms of the two wheels exclusively and only through the traction rods (41). The compression of the spring (16) is realized by the movement in the CAFU axial sliding bearers which has an inverted direction in relation to the previous, whilst the adjustment of the height of the side of the vehicle is realised by a negative increase in the length of the LAD, namely by a reduction in the length. This case is presented to demonstrate the variety of connections through which it is possible to realize the implementation of the present invention; and it is possibly the single case of flexible interconnection of two same side wheels where even without the existence of auxiliary rotating arm levers, it is possible to achieve a satisfactory fluctuation in the leverage ratio of the wheel suspension relative to its path.

Two alternative proposed linkages are presented in figures 20 (a, b). In that case, the auxiliary arm lever (42) is not joined directly to the vehicle body rather it constitutes the connection of a mechanism which in the technical terminology is known as a "4-Link Mechanism" and which rotates around a momentary and not a fixed rotation axis. The other two links in the 4-Link Mechanism are the arm lever (105) as a first crank and the crank-follower (44), in the case of figure 20a or the two crank- followers (44) in the case of figure 20b; in both cases, the fourth link is taken to be that linear section of the vehicle body that intervenes between the joints on the vehicle for the two cranks.

Through the mechanism in figure 20 (a, b) we have two choices which, under certain preconditions, may be even simultaneously satisfied, where this is desirable. The first is that this linkage is utilised as a "generator for a linear path" in order that the joint (17) between the auxiliary arm lever (42) and the CAFU (15) moves in a satisfactory approximation upon the axis for the compression - extension of the CAFU or parallel to it where the CAFU has a certain specific form.

The second is that this assembly is utilised as a "function generator" between the suspension arm (5) and the CAFU so that the alteration in the Instant Leverage Ratio of the wheel shall follow our more composite requirements.

To date, through the development, in an obvious manner, of the technical level of the joined rods mechanism, multiple versions of the combination for the mechanism of the present invention with longitudinal arm suspensions have been presented. Despite these, it does not also preclude the capacity for the development of the present invention in vehicles that provide a different type of suspension at the known technical level. The mechanism of the present invention may be installed in a vehicle either at manufacture or at a later stage (retrofit), thus providing to it the advantages that are described in figure 2, however not those that are described in figures 6 and 7, unless it is accompanied by longitudinal arm suspensions.

In figure 21 is depicted one version of the combination of the present invention with a suspension system comprised of two rigid axles (39), one at each end of the vehicle. For the purpose of simplifying the plan, the figure of the vehicle body has been omitted together with the wheels and the CAFU with the corresponding assembly on the left side. On the right side of the vehicle is illustrated an indicative version of the auxiliary arm levers (42, 43) which are joined in such a manner so that they rotate about the axes that are vertical in relation to the vehicle body. In the specific case, the longitudinal arms (5, 2) for the front and the rear wheel, correspondingly, are not connected directly to the wheels but, through the corresponding, for each wheel, rigid axle. In figure 22 is depicted an indicative version of the present invention where the wheels are suspended on transverse arms (52, 53) which are connected through the corresponding auxiliary arm levers (42, 43) for the CAFU (15) through push-pull rods (41); and again, for the purpose of simplifying the plan, the figure of the right wheels for the vehicle and their corresponding flexible interconnection has been omitted.

Nose dive - tail dive

Nose dive is the rotation of the vehicle body about the transverse in relation to the vehicle axis. It is caused by the tendency for the compression of the entire front section of the vehicle and the extension of the rear, as a result of the reduction in the vertical load by the rear wheels and the simultaneous increase in that of the front wheels, as for example, occurs during the braking of the vehicle. Conversely, tail dive is the reverse, to that of the nose dive, rotation of the vehicle about the transverse axis and it is caused by the transfer of the vertical load from the front to the rear wheels, for example, during acceleration. The flexible interconnection, in accordance with the present invention, of the front with the rear wheel on either side, permits the display of some initial amounts of nose dive and tail dive during deceleration and acceleration, correspondingly. One innovation, that is inherent of the present invention, constitutes the fact that the initial appearance of nose dive and tail dive results in the alteration of the Instant Leverage Ratios between the wheels on either side with the result of the "automatic" retardation in the further increase of the phenomenon.

This phenomenon is due to the fact that the structure of the mechanism, as it has already been presented, provides to each wheel an Instant Leverage Ratio which has a large value during the complete extension of the wheel and which tends to continually drop during the compression that follows.

This implies that the suspension of the wheel exhibits minor resistance during its initial compression and all the greater, thereafter.

It is this evident that, further to the commencement of the nose dive phenomenon, the further compression of the front wheels shall tend to be less than the extent of the rear wheels, of which their Instant Leverage Ratio shall tend to be continually reduced. The reduction in the Instant Leverage Ratio of the rear wheels shall have as a consequence the compression of their suspension, despite the reduction in the vertical load due to the braking. The final result, in a vehicle that is equipped with the suspension mechanism of the present invention, is to exhibit a tendency for the total lowering of the vehicle body which, in most cases, is more pronounced than the tendency of the vehicle to simply deviate, from the horizontal position and to exhibit nose dive. Corresponding phenomena are also exhibited immediately further to the initial tail dive, during acceleration.

These favourable phenomena of the self - balancing of the vehicle are that much more apparent, from manufacture, for the larger "initial" Instant Leverage Ratios of its wheels (during the complete extent of their suspension) in comparison to the "final" Instant Leverage Ratios (that appear when the suspension approaches the limit for their maximum compression, within the limits of the Active Path for each of them.) Out of those that have been previously mentioned to this point it is concluded that when one side of the vehicle has been adjusted to the minimum possible height from the ground, the mechanism under the present invention has a limited capacity of resistance to the nose dive and the tail dive, granted that during the commencement of the rotation of the vehicle body about the transverse axis, the Instant Leverage Ratios between the front and the rear wheels, are not sufficiently differentiated. This phenomenon constitutes, potentially, a problem in the case where the LADs of the CAFUs on both sides of the vehicle are adjusted in such a way that the vehicle, in its entirety, is situated at its lowest possible height. For example, during movement along a level asphalt mat, the initial requirement is a minimisation of the height of the gravity centre.

Further to this, it has been demonstrated to be extremely useful, in parallel to the flexible interconnection for same side wheels through CAFU, and the co¬ existence of an additional mechanism which shall henceforth be known as the Longitudinal Stability Mechanism. Through this mechanism is realised a secondary flexible assembly for the interconnection of the wheels of the vehicle for the purpose of augmenting the resistance in the arrangement for each CAFU during nose dive and tail dive. One specific requirement by this additional mechanism is that it has a differentiated degree of reaction, in accordance with the then selected height of the vehicle.

Thus, the more that one side of the vehicle is raised, through the adjustment of the LAD, then the reaction of the additional mechanism must be that much less, in order not to nullify the previously mentioned requirement for an increase in the Leverage Ratio for each wheel on the raised side, in comparison to those on the non raised side.

One (low quality, in terms of output) auxiliary system of the flexible interconnection of the wheels which belongs to the technical level and which operates as a Mechanism for Longitudinal Stability through which the already described problem is solved, is presented as an example, in figure 23. For the purpose of simplifying the plan, the CAFU and its connection to the suspension arms of the wheels is not illustrated, which in the specific example are transverse. Similarly, for reasons of simplification, the illustration of the two right wheels and their flexible interconnection has been omitted.

The transverse arms (52, 53) that suspend the wheels on the left side are connected between themselves by a torsion bar that is comprised of two sections (61 A, 61B) that move independently from one another, when the height of the left side has been adjusted from one size and above. When however, through the LAD in the CAFU, the height of the side has been adjusted from one size and below, the coupler (62) that is interposed between the two sections of the torsion bar is activated and connects the two halves of the rod, compelling them to move simultaneously at the point of their engagement. In this manner, the compelled compression of one wheel, results in a deformation of the torsion bar and compulsion for compression for the other wheel on the same side. It is evident that the extent in each deformity of the torsion bar is dependent upon the resistance that the CAFU spring applies to the simultaneous compression of both wheels on the same side. The method for the activation of the coupler (62) may be either mechanical or electromagnetic or hydraulic, through a typical mechanism of the existing technical level. The mechanical, electrical or hydraulic input signal of the coupler activation mechanism is the then adjustment of the LAD through which the height for the specific side of the vehicle is determined.

In order to avoid the complexity in the operation of the already described mechanism of an even balanced flexible interconnection of the wheels on the same side, in figure 23, another mechanism is proposed, which shall henceforth be known as the Mechanism for the Diagonal Flexible Support, which constitutes an element of the present invention and whose operation is described hereunder.

Second half of the invention: Diagonal Flexible Support with variable leverage ratio

The already presented (example) mechanism for an even balanced flexible lateral interconnection in figure 23 does not provide any other advantage than the resistance to nose dive and tail dive when both sides of the vehicle have been adjusted, through the corresponding LAD, to a height which is in the "region" of the least permissible.

However, as it has been experimentally demonstrated, the basic linkage of the present invention (suspension through floating CAFU), may take maximum advantage where instead of a balanced lateral support, such as that in figure 23, preference is given to a balanced diagonal flexible support; and with this term we imply the flexible interconnection, per two, of the wheels that are located at the diagonal positions of a four wheel vehicle, and in such a manner so that the compression in the suspension of one wheel shall tend to also cause a compression in the other.

Through the assembly of the diagonal flexible support that shall be described subsequently, it is possible, beyond the monitoring of nose dive and tail dive, to provide additional increased capabilities for traction to the three wheels of the vehicle, where the fourth passes over a protrusion in the terrain with a great height, as described in figure 24.

In figure 24 we have a vehicle with CAFU suspensions whose rear left wheel (RL) passes over a protrusion in the terrain with a great height. As it is evident, the suspension for the rear left wheel shall be compressed, as well as that for the front right (FR). Due to a transfer of the loads, the suspension on the rear right (RR) wheel shall also be significantly compressed whilst, conversely, that on the front left (FL) shall be extended. In many cases, such as that in the previously mentioned illustration, it is possible, that despite whatever extension in its suspension, the specific wheel (FL) shall lose its contact with the ground, as in the illustration. The theoretical solution, in such a difficult case, would be to reduce, through a suitable flexible interconnection in the wheels, the compression in the suspension of the front right wheel (FR) or, correspondingly, to increase the compression in the rear left (RL). In this manner, the tilt to the right (around its longitudinal axis) of the vehicle would be reduced. As a result, there would be the benefit of maintaining ground contact by the front left (FL) wheel.

The flexible interconnection of the front right wheel (FR) and the rear left (RL) in such a manner that, when the suspension is compressed in one of the two it shall compel to a corresponding (but evidently not equivalent) compression of the suspension in the other, constituted the response, to the specific problem. As it was also demonstrated by an experimental implementation of this method, we had a significant reduction of the tendency of the vehicle to rotate to the right about an axis vertical in relation to the diagonal axis that is determined by the points of contact with the ground by the wheels FR and RL. The final result being, a reduction in the potential for the raising of the wheel FL, from the terrain surface It follows that, for reasons of symmetry, the corresponding diagonal flexible interconnection of the wheels FL and RR is also required, in order that this arrangement shall "protect" all the wheels of the vehicle from a potential elevation from the terrain surface. Usually, the diagonal flexible interconnection of the wheels of a vehicle is achieved through a hydraulic system, which, as it has been previously stated, is not desirable in the present invention.

A method for the diagonal flexible support, through an exclusively mechanical arrangement was proposed in 1961 in the patent document US3147990

(Wettstein), where in pairs, the wheels of the vehicle located in diagonals, are connected with longitudinal torsion bars, through arm levers, in such a manner that the compression of the suspension of one wheel results in a tendency for compression of the suspension of the wheel that is located in the diagonal position on the vehicle.

However, as an expert on suspension can deduce, this assembly, despite of its any advantages, is destined to a small range of suspension travel, which is destined to be used on an exclusively smooth road surface. This is also demonstrated by the assembly of the dual transverse uneven (and short) length arms that have been selected for the specific application. A suspension arrangement best suited for suspensions with limited wheel travel range, used almost exclusively on "on-road" vehicles. Furthermore, regardless of the selection of uneven length transverse arms, this assembly is unable to operate in conjunction with the mechanism for the selected 00027

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increase of the height of one side of the vehicle. Where, for example, the left side of the vehicle is raised, the diagonal interconnection of the wheels shall also result in an elevation, of one part, of the right side, which is an undesirable occurrence.

The mechanical assembly for the even balancing of the diagonal flexible support that is proposed by us, whilst it follows, the basic principle for the operation the arrangement that is proposed by patent document US3147990 (Wettstein) it has however been significantly varied with the assistance of intermediary auxiliary rotating arm levers, in such a manner that, through innovative arrangement, it shall achieve the following advantages:

A) A monitoring of the tendencies to nose dive and tail dive by the vehicle throughout the entire range of movement of the wheels suspension as well as throughout the entire range of the magnitude for the selected elevation of one or the other side of the vehicle, which is achieved through the adjustment of the LAD for the primary flexible interconnection of the wheels that has already been described. B) A minimisation of the resistance forces that are emitted by the diagonal flexible support mechanism in the case of an increase of the height on one side of the vehicle and a reduction in the height on the other side.

The basic principle for the diagonal flexible support between the two wheels of the vehicle, for example, on the front left and the rear right, are depicted in figure 25a, from which, for reasons of simplicity, has been omitted the illustration of the remaining wheels, the two CAFU and the corresponding assemblies.

The front left trailing arm (5) is rigidly connected to the corresponding bearing axis (255) which rotates according to the motion of the wheel, upon bearings that are rigidly adapted to the body (100) of the vehicle. Upon the housing axis (255) the front arm lever (205) is rigidly adapted so that it follows the angular motions of the housing axis (255). Correspondingly, on the rear right wheel, the right trailing arm (2) is joined through its rotating axis (222) to bearings that are rigidly adapted to the body (100) of the vehicle. The rear arm lever (202) is rigidly adapted to the axis (222).

Between the front and the rear arm lever (205 and 202, correspondingly) a flexible unit (215) is interposed which shall henceforth be known as the Diagonal

Flexible Unit (DFU) which is connected to the corresponding arm levers through the push-pull rods (241). The principle for the operation of the DFU (215) is depicted in figure 25b. The one connecting terminal (218) is connected to a piston (217) on either side of which there are two springs (216A, 216B), that are compressed between the piston and the body of the DFU, to which body is connected the other connecting terminal (219). From the illustration it is evident 27

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that through the DFU is flexibly transmitted the motion tendency of each wheel on the same direction as that of the other wheel.

In figure 26, the DFU has the shape of a torsion bar (220) which flexibly transmits the vertical relocation of one wheel to the other, through push-pull rods (241 ).

Let us now consider that both wheels in figure 25a are not in contact with the ground and that one of those is located in a random position during the compression of its suspension. The further slight increase (Ab₁) in the suspension's compression shall result in a corresponding increase (Ab₂) in the compression of the other. Under the previously mentioned assumptions, we determine as the Instant Diagonal Leverage Ratio (IDLR) for a wheel, the ratio of an increase in its displacement (Ab₁) in relation to the corresponding increase in the displacement (Δb₂) which, through the diagonal connection, is caused to the other wheel, without any deformation in the spring of the DFU. Namely,

IDLR = AbW Ab₂

As one will note, when (through the LAD) the height on one side of the vehicle is increased, the assembly for the diagonal flexible support of the wheels shall also result in the partial elevation of that side of the vehicle that we do not desire to raise.

The undesired elevation of the specific side shall be that much greater as "harder" as the DFU spring or DFU torsion bar is, and as lesser, per compression grade, as the IDLR is, for the wheel that is located in the side of the desired elevation.

Further to the above, the restriction in the elevation of that side where the elevation is undesirable may be achieved in two ways; Either through the selection of a very "soft" spring or torsion bar for the DFU or through the selection, per case, of a suitable leverage ratio of the linkage between the diagonally interconnected wheels. As it is rendered apparent in accordance with the previously mentioned, where the IDLR for a wheel increases as it extends, correspondingly, where it decreases as it moves upwards, then the specific (per two wheels), diagonal evenly balanced interconnection for the four wheels of a vehicle, shall have the following favourable results: a) The minimisation of the undesired elevation of the low side of the vehicle, when the other side is selectively raised, through the adjustment of the LAD b) The minimisation of the additional resistance in the upward motion of the wheels for the raised side of the vehicle, during the operation of their suspension, which is promoted, through the diagonal flexible connection, by the CAFU on the "low" side of the vehicle. As someone that is experienced in the kinetics of mechanisms can verify, the fluctuation in the IDLR for each of the wheels that are diagonally interconnected, in figures 25α and 26, remains close to the unit throughout the entire range of the extension or the compression of the suspension for the specific wheel. Conversely, in accordance with everything that has been previously mentioned, the fluctuation in the IDLR for a wheel must commence from a high value at the point of its maximum extent and tend to continually reduce as the compression of its suspension increases. In figure 27 are depicted certain hypothetical graphic representations (A, B, C, D) in the desired alteration of the IDLR in relation to the compression of the suspension for the wheel. The value 0, on the horizontal axis, delineates the point for the maximum extension of the wheel and the value IDLRo the minimum desired value for the IDLR for a wheel at its full compression. These curves are simply indicative in relation to their desired shape which is characterised by the negative prefix of the first derivative during the entire practical alteration range of the corresponding function or at least, for its larger section, without of course excluding any other curve which also follows in the spirit for the specific implementation.

In order to render possible the "implementation" of a specific, suitable shape for the IDLR alteration curve, we submit the innovative use of auxiliary arm levers, of a specific form, of which arm levers, at least one shall be interposed, in series, between the DFU and one of the two wheels diagonally connected, through it. The requirement of the specific innovation is the forming of a suitable function of IDLR variation during the movement of each wheel in such a manner that it shall accept values of a large magnitude when the wheel is moving towards its complete extension. And, conversely, small magnitude values when it is moving towards its complete suspension compression. These special auxiliary arm levers, henceforth to be known as, the diagonal auxiliary arm levers, are joined to the vehicle body, whilst at least one of their points, located at a distance from their joint, is interposed in series to the diagonal interconnection mechanism of the two wheels of the vehicle. In the where the DFU is of a torsion rod form with a ¹Tl" shape, the diagonal auxiliary arm levers may also be and the limbs of the rod itself, shaped in a specific manner.

In figures 28-31 are depicted various indicative versions of the diagonal flexible support between the front left (FL) and the rear right (RR) wheel of a vehicle, without also excluding any other, in accordance with the spirit of the present invention. For the purpose of simplifying the specific figures, some of which represent the front left (FL) and the rear right (RR) wheel as if they are on the same level, a fact that does not actually exist. This clarification is made to avoid potential confusion. In figure 28, the diagonal auxiliary arm lever (242) is interposed between the push-pull rod (241) coming out of the front left suspension and the DFU (215) in such a manner so as to impose a relatively minor differentiation between the maximum and the minimum IDLR of each wheel, at complete extent and at complete compression, correspondingly. In figure 29, the diagonal auxiliary arm lever (242) is joined at a point that is different to those of its terminals. In that case, the terminals in the arm lever are those which are interposed, in series, onto the flexible interconnection mechanism between the front left (FL) and the rear right (RR) wheel. In figure 30 is depicted an arrangement with two diagonal auxiliary arm levers (242A, 242B) between which is interposed the DFU (215). This arrangement provides an increased difference between the maximum and the minimum values in the IDLR for each wheel at its complete extend and complete compression, correspondingly.

In figure 31, the DFU has a torsion bar shape (220) whilst its limbs (220A, 220B) constitute the diagonal auxiliary arm levers. The depicted initial angle of the non co-rotating limbs in relation to the vertical and transverse level to the schema, is such that, in conjunction with the specific shape of the longitudinal arms (5, 2) and the angle of the arm levers (205, 202) at the front left (FL) and the rear right (RR) wheel, correspondingly, they provide an exceptionally high value IDLR, for each wheel, when it is at its full extent. Obviously, in this special arrangement, we consider the straight part of the bar as the DFU and the "twisted" limbs as auxiliary arm levers.

It is evident that the thus far proposed, in the present application, assemblies for the diagonal flexible support are simply indicative of the manner for the development of one or more diagonal auxiliary arm levers, in order to achieve the desired mathematical function for the IDLR values during the suspension travel of a wheel.

However, as anyone who has the relative experience in the composition of mechanisms can verify, it is possible to compose an infinite number of linkage shapes for the diagonal support, by remaining austerely within the terms of the spirit of the present invention and by developing, in an obvious way, the existing technical level of the joined mechanisms. However, out of all these potential alternative assemblies, those that are in a position to provide desirable shape of the IDLR function have one common point which also constitutes an axiomatic element of the present invention: and this is the existence of at least one auxiliary diagonal arm lever, of any suitable shape, that is interposed in series between the DFU and one of the diagonally interconnected wheels.

In conclusion, the unknown in this specific part of the present invention was to discover an original method so as to render possible the incorporation of the qualities of technical level US3147990 into the environment of the main body of the revealed innovation that relates to the simultaneous alteration of the height and the leverage ratio variation through the CAFU / LAD couple between same side wheels of a vehicle. As it has already become evident, these two "competitive" systems (two flexible interconnections, one for same side wheels and one for diagonal wheels) may render possible, through the suitable calculations, the compatibility to one another and co-operation between them, throughout the entire spectrum of the operation of wheels suspension and the entire range of the alteration of the LAD length and height on either side of the vehicle. With the revelation of the innovation of the interposition of the diagonal auxiliary arm levers in series to each of the two DFU, for the first time, the phenomenon of the non-compatible co-existence of "same side - counter momentum" and the "diagonal - similar momentum" flexible interconnection of the wheels became possible, through an exclusively mechanical method. This was made possible by the flexibility that was provided to the designer by the presence of the diagonal auxiliary arm levers in order that he may suitably transform the mathematical function of IDLR values during the independent movement of every wheel.

Further to all of the above, it is undoubtedly evident that the mathematical calculation of the kinetic alteration in the whole of the moving members both the collaborating mechanisms and, simultaneously, of the relative deformities in the interposed flexible units (CAFU and DFU) it becomes a relatively simple matter for whoever has the relative experience in kinetic analysis and the composition of simple joined mechanisms and especially for those that compose vehicle suspensions.

Claims

1. Wheel Suspension System for a four-wheel vehicle comprising of longitudinal (2, 5) or transverse (52, 53) arms, or combination of longitudinal and transverse arms, each of which is articulated onto the body (100) of the vehicle and is linked to the corresponding wheel (3, 6) at its end. Moreover, on each side of the vehicle, two of these four arms, one per wheel, are linked elastically with each other through a floating CAFU (Common, Axially Flexible Unit) (15) and at least one rotating auxiliary arm lever (42, 43, 44), placed in series, so that whenever the suspension of a wheel is under compression, the suspension of the other wheel on the same vehicle side tends to expand in a progressive interconnection manner, whilst the CAFU of each vehicle side is linked in series to a LAD (Length Adjusting Device)(18). The System is characterized by that the Reference Height of each vehicle side is variable and depends on the then current length of the LAD of the corresponding CAFU and by that, whenever the length of the LAD on one vehicle side ranges between two marginal values μi and μ₂, then the increase of Reference Height of the said side entails a concurrent increase of the Active Travel and the Mean Active Leverage Ratio of each of the corresponding wheels of this vehicle side.

2. Wheel Suspension System, according to claim 1 , characterized by that the Total Instant Leverage Ratio of each wheel is greater than its Mean Active Leverage Ratio, when its individual suspension is fully expanded, and less than its Mean Active Leverage Ratio, when its individual suspension is fully compressed.

3. Wheel Suspension System, according to claims 1 and 2, characterized by that a rigid axle (39) is placed between, at least, one arm (2, 5) and the corresponding wheel.

4. Wheel Suspension System, according to claim 1, characterized by that each pair of wheels located diagonally opposite on the vehicle are linked elastically by way of a DFU (Diagonal Flexible Unit) (215) and at least one rotating diagonal auxiliary arm lever (242), placed in series, so that whenever the suspension of a wheel is compressed, the suspension of the wheel located diagonally opposite also tends to be compressed.

5. Wheel Suspension System, according to claims 1 and 4, characterized by that each of the four wheels displays greater Instant Diagonal Leverage Ratio when fully expanded and lesser when fully compressed.

6. Wheel Suspension System, according to claims 1 and 2, characterized by that the raising of the vehicle side is effected by way of negative length increase of the LAD connected, in series, with Reverse CAFU (15A), and no auxiliary lever arm is placed in series within the arrangement of elastic linkage between two wheels on the same vehicle side.

7. Wheel Suspension system, according to claim 6, characterized by that at least one auxiliary arm lever is placed in series between the Reverse CAFU (15A) and one of the two wheels on the same vehicle side.