FR3100009A1 - Extension wheel and mobility system implementing one or more extension wheels - Google Patents

Abstract

"Extension wheel and mobility system implementing one or more extension wheels" Extension wheel comprising a rim receiving a tread, and a coaxial inner circular part connected to said rim by a plurality of spokes. The inner circular part comprises adjustable means for removably enclosing an initial wheel of diameter smaller than that of said extension wheel, so that the extension wheel performs a rolling function and the initial wheel performs a function of hub. Mobility system comprising one or more extension wheels according to the invention. See figure 1

Description

Extension wheel and mobility system implementing one or more extension wheels

Field of invention

The present invention relates to an extension wheel for enlarging the diameter of an initial wheel. It also relates to mobility systems equipped with such extension wheels.

There is currently a strong demand for scalable mobility systems adapted to the diversity of needs and contexts. In particular, the question arises of reducing the space and the cost of these individual mobility systems by making them scalable, in a context of soft mobility.

In particular, the question arises of changing the diameter of the wheels of mobility systems. Technological proposals for wheels of variable diameter do not exist and do not provide a simple and inexpensive solution to implement.

Mention may in particular be made of an adjustable-diameter wheel technology proposed for robotic vehicles, disclosed in the document US6,860,346B2. However, the wheel obtained with this technology cannot have a rim and even less a tread.

Furthermore, another object of the present invention is to propose a wheel which can also be folded up in order to allow it to be transported under conditions of optimum compactness.

There have already been technical proposals for folding wheels with spokes, such as the one invented by Lucien Champion and disclosed in patent n°678.098 which had as its object an extendable rim divided into several segments. This rim consisted of several segments linked together which thus allowed an extension of this rim. However, the rim thus disclosed only allowed an extension and was not attached to a pneumatic part. Duncan Fitzsimons also invented a spoked folding wheel, disclosed in EP2164714. However, the wheel thus disclosed has in folded mode a length substantially equal to the unfolded diameter.

Patent EP 33444472, proposes a folding wheel whose pneumatic segments are connected on themselves but each concept has independent treads that can be separated from each other during folding without the possibility of quick disassembly.

The object of the present invention is thus to propose a wheel technology providing an extension of the diameter of an initial wheel, which offers interchangeability without dismantling the energy transmission chain, thus providing possibilities of evolution of the utilization of a vehicle far greater than that obtained with current systems. Another goal is to propose that this extension wheel is also foldable.

This objective is achieved with an extension wheel comprising a rim receiving a tread, and a coaxial inner circular part connected to said rim by a plurality of spokes.

According to the invention, the inner circular part comprises adjustable means for removably enclosing an initial wheel of diameter smaller than that of said extension wheel, so that the extension wheel performs a rolling function and that the wheel initial provides a hub function.

When the extension wheel according to the invention is implemented for the extension of an initial wheel provided with a tread, the adjustable means can advantageously comprise a strapping piece to grip this tread.

The adjustable clamping means may comprise manually operable lever means, and means for axially locking the strapping part with respect to the tread of the initial wheel.

The strapping piece may include patterns in relief on its inner face in contact with the tread of the initial wheel.

The extension wheel according to the invention may further comprise motorization means arranged in the inner circular part and in mechanical interaction with the initial wheel. These motorization means may for example comprise a plurality of drive rollers arranged between the inner circular part and a rim of the initial wheel

The drive rollers can also be arranged between the inner circular part and a tread of the initial wheel.

The motorization means can also comprise an electromagnetic coupling system comprising a rotor part connected to the inner circular part and a stator part integrated into a rim of the initial wheel.

The extension wheel according to the invention may further comprise energy storage means provided to supply the motorization means. These energy storage means can be arranged in the inner circular part.

In a particular form of the invention, the extension wheel according to the invention can be foldable.

The rim of the extension wheel may be composed of rim segments each provided with a tread segment movable in rotation relative to the rim segments and means for locking the rim so that two adjacent rim segments are locked. These locking means can for example comprise magnetic locking means.

Each rim segment can be connected to the inner circular part by means of a first spoke and a second spoke having outer ends connected to both ends of the rim segment and inner ends connected to the inner circular part at two points diametrically opposed.

The extension wheel can be arranged so that in folded mode, the rim segments are arranged on either side of the inner circular part in two sets of rim segments having a diameter substantially equal to or less than that of the inner circular room. Each set of rim segments may include non-adjacent rim segments.

According to another aspect of the invention, there is proposed a mobility system adapted to receive at least one extension wheel according to the invention.

For a mobility system according to the invention, of the wheelchair type, the latter then comprises a seat and an axle fitted at its two ends with two initial wheels intended to be coupled to two extension wheels according to the invention.

The axis can be equipped with a Segway placed under the seat and comprising two directional actuators driving the two initial wheels, each coupled to an extension wheel.

The two directional actuators of the Segway can advantageously be controlled by means of the armrests of the chair.

For a mobility system according to the invention, of the draisienne type comprising a frame and two pairs of initial wheels parallel on two axes respectively front and rear, the frame is extensible and provided to receive extension wheels according to the invention in coupling with the initial wheels.

For a mobility system according to the invention, of the single-arm bicycle type comprising a frame and two initial wheels, these two initial wheels are provided to receive two extension wheels according to the invention.

For a mobility system according to the invention, of the scooter type comprising a first rear part constructed on a bicycle base and a rear wheel and a second front part comprising a base and two front wheels on a common front axle, the two front wheels are provided to receive two extension wheels according to the invention. The rear wheel can be provided to receive an extension wheel according to the invention. The front axle can be motorized by means of a gyropod driving two initial wheels, and the rear part based on a bicycle can be decoupled from the front part.

Description of figures

The invention will be better understood on reading the following description of some preferred embodiments:

Figure 1 shows a first example of an extension wheel according to the invention, coupled to a first example of an initial wheel;

FIG. 1a illustrates a strapping part implemented in an extension wheel according to the invention, in the released position and in the locked position;

Figure 2 shows the extension wheel of Figure 1, in which the hoop piece has been unlocked;

Figure 2a shows a first example of an initial wheel;

FIG. 3 represents the extension wheel of FIG. 1, not coupled to an initial wheel;

Figure 4 illustrates the extension wheel of Figure 3, coupled to a second example of an initial wheel;

Figure 4a shows a second example of an initial wheel;

Figure 4b illustrates a second example of an extension wheel according to the invention, provided with a motorization system;

Figure 5 shows an example of a Segway (overboard) implemented in mobility systems according to the invention;

Figure 6 schematically shows a wheelchair equipped with two extension wheels according to the invention;

Figure 7 schematically illustrates a child's bicycle that can receive two extension wheels according to the invention;

Figure 8 schematically shows the bicycle of Figure 7, equipped with two extension wheels according to the invention;

FIG. 9a schematically represents a first example of a mobility system of the scooter type, coupled to a “cargo” container and receiving two front extension wheels according to the invention;

Figure 9b schematically represents a motorized wheelchair intended to be coupled to a bicycle rear structure;

FIG. 10 schematically represents a second example of a scooter-type mobility system, the rear wheel of which can receive an extension wheel according to the invention;

Figure 11 illustrates the use of a mobility system of the scooter type according to the invention, equipped on its front axle with two extension wheels according to the invention;

Figure 12 illustrates the use of the mobility system of Figure 11, receiving a compartment designed to accommodate a person, in particular a child;

Figure 13 shows a mobility system according to the invention of the balance bike type;

Figure 14 shows the mobility system of Figure 13, equipped with two pairs of extension wheels according to the invention;

Figure 15 is a schematic front view of a foldable extension wheel according to the invention, in operational mode;

Figure 16 is a perspective view of the collapsible extension wheel of Figure 15;

Figure 17 shows a detail of the collapsible extension wheel of Figures 15 and 16;

Figure 18 is a schematic front view of an embodiment of a foldable extension wheel according to the invention;

Figure 18a shows a rim segment embodied in the collapsible extension wheel of Figure 18;

Figure 18b schematically illustrates two foldable extension wheels according to the invention, in unfolded and locked mode for use in a wheelchair;

Figure 19 schematically illustrates the two foldable extension wheels of Figure 18b, in folded mode;

Figure 20 schematically illustrates one of the extension wheels of Figure 18b, in an intermediate position during its folding;

Figure 21 schematically illustrates the extension wheel of Figure 20, in folded mode;

Figure 22 illustrates, for another embodiment of a foldable extension wheel according to the invention, in which the inner circular part is composed of two sliding inner circular parts, one of these sliding circular parts and its set of associated rim segments;

Figure 23 schematically illustrates, for this alternate embodiment, a deployed collapsible extension road;

Figures 24 and 25 illustrate different stages of deployment of the collapsible extension wheel of Figures 22 and 23;

Figure 26 is a perspective view of one of the collapsible extension wheel portions of Figures 22-24, in collapsed mode.

Will now be described with reference to the aforementioned figures, several embodiments of extension wheels according to the invention.

Referring to Figures 1 to 4, an extension wheel 1 according to the invention comprises a rim 141 receiving a tread 460 and an inner circular part 2 concentric with the rim and connected to the latter by a set of spokes 3 .

The inner circular piece comprises a strapping piece 200 actuated by a lever 20. As illustrated by FIGS. 1 and 2, this strapping piece 200 has the function of enclosing a tread 40 of an initial wheel 5 comprising a rim 51 and a motorized hub 52. With reference to FIG. 1a, when the strapping part 200 is unlocked (lever 20 not actuated), it is impossible to insert the initial wheel 5 into the extension wheel 1. By actuating the lever 20, the strapping part grips the tread 50 of the initial wheel 5. A complete wheel is then obtained comprising a means produced by the initial wheel 5 and a rim and its tread which are produced by the wheel d extension 1.

The extension wheel 1 can be applied to various other types of initial wheel, for example an initial wheel 4 comprising a full and smooth tread 40 on a rim 41, with a non-motorized hub 42.

It is also possible to provide, with reference to FIG. 4b, an extension wheel 1′ incorporating motorization means. Thus the extension wheel 1 'comprises an inner circular part 2', connected by spokes 31-34 to a rim carrying a tread, which comprises four electric actuators (not shown) provided with drive rollers 201-204 in contact with the tread 31 of an initial wheel 4. This initial wheel can either be kept immobile, or have its own motorization via a hub. The electric actuators can be powered from storage units built into the inner 2' circular part of the extension wheel or from another location such as the spokes.

In a first example of implementation of the invention illustrated by FIGS. 5 and 6, extension wheels 1.1, 1.2 applied to two initial wheels 13.1, 13.2 of a Segway 10 (or "hoverboard"), will allow to motorize a wheelchair 6 at low cost. This wheelchair 6, which comprises a seat 62, a backrest 60, and two small front wheels 64.1, 64.4 connected to a base supporting the seat 62 by two tubular parts 63.1, 63.2, comprises furthermore the Segway 10 whose two wheels 13.1, 13.2 will ensure the motorization function for the two extension wheels 1.1, 1.2. This Segway 10 commonly comprises two directional electric actuators 14.1, 14.2, the orientation of which is mechanically controlled by two arms (not shown) connected to two armrests 61.1, 61.2 of the chair 6 located on either side of its seat 62. treads 12.1, 12.2 of the two initial wheels 13.1, 13.2 of the Segway 10 are firmly enclosed in the strapping parts 2.1, 2.2 of the two extension wheels 1.1, 1.2. The motorized hubs 11.1, 11.2 of the initial wheels 13.1, 13.2 of the Segway 10 then become the motorized hubs of the wheelchair 6.

It is important to note that the same extension wheels used for this wheelchair can be used for many other mobility systems, including bicycles, balance bikes or scooters. This generic character of extension wheels can advantageously contribute to decompartmentalizing the wheelchair sector and modify the usual perception of the public with regard to people with reduced mobility using these wheelchairs.

With reference to Figures 7 and 8, the present invention can be implemented to provide an evolving bicycle for children 7. This evolving bicycle 7, of single-fork structure, normally provided with a frame 70, a support tube saddle 74, a handlebar tube 75, a front fork 71 and a rear fork 73, comprises two initial wheels 72.1, 72.2 of small diameter. Two extension wheels 1.1, 1.2 according to the invention can be easily coupled to the initial wheels 72.1, 72.2 by a simple positioning of these extension wheels around the initial wheels followed by an actuation of the levers 20.1, 20.2 to firmly grip these initial wheels. We thus have a bicycle equipped with wheels of greater diameter. Provision can be made for the frame 70 of the bicycle 7 to be mechanically extensible, using known techniques for extending the front and rear forks and the central part of the frame 70.

The present invention provides many possibilities of evolution for so-called soft mobility systems which are expected to develop massively in urban and peri-urban areas in the coming years. Thus, with reference to Figures 9 to 11, new mobility system structures will be able to be designed thanks to the implementation of extension wheels according to the invention combined with electric motorization systems of the Segway type which have largely widespread and have become economically accessible to all.

Thus, with reference to Figures 10 and 11, a three-wheeled scooter 9 comprises a rear part B built on a rear bicycle base and a modular front part A and provided with two front wheels 1.1, 1.2 on the same axle which can be motorized.

The rear part B comprises a frame 97 comprising a rear mono-fork 93 provided with an initial drive wheel 92.3 to which an extension wheel 1.2 is coupled by means of a strapping part 2.2, a substantially vertical part 95 provided for carry a handlebar 96, and a mechanical coupling part 93 provided to achieve a coupling 94 with the front part A.

The front part A comprises a substantially planar modular base 93 receiving an axle (not shown) comprising at its two ends the two front wheels constituted by two extension wheels 1.1, 1.2 coupled to two initial wheels 92.1, 92.2 by a strapping part 2.2.

This scooter can have several operational configurations, as illustrated in Figures 9a, 9b, 9c. In a first configuration (9a), the scooter 9' is used in "cargo" mode with a container 97 fixed to the modular base 93. This scooter has two front wheels of the extension type 1.1, 1.2 and a conventional rear wheel. The two extension wheels 1.1, 1.2 can be motorized, using for example a Segway of the type described with reference to Figures 5 and 6.

It is also possible to provide a configuration of the scooter type in which the front part A is produced by a wheelchair 6 motorized by means of a Segway 10, as shown in FIG. 9b. This configuration is particularly useful for the social integration of people with reduced mobility because it makes it possible to move in a valid-invalid tandem, by implementing existing modular equipment.

Referring to Figure 12, a scooter 9 can be converted into a mobility system 9 "configured to transport one or more children in a cabin 12 fixed to the modular base 93. This scooter 9" has an electric motor assistance via its two front extension wheels 92.1, 92.2.

Extension wheels according to the invention can also be used to make a balance bike 13 scalable, as illustrated in Figures 13 and 14. The balance bike 13, normally equipped with a front tube 134 carrying a handlebar 136 and a rear tube 133 carrying a saddle 135 and a frame 132 provided with a front axle 138 and a rear axle 139, initially comprises a first pair of front wheels 131a, 131b whose hubs are fixed on either side of the front axle 138, and a second pair of rear wheels 132a, 132b whose hubs are fixed on either side of the rear axle 138. Extension wheels 136a, 136b; 137a, 137b can be coupled to the initial wheels 131a, 131b; 132a, 132b and secured by means of strapping parts 204a, 204b; 205a, 205b.

An extension wheel according to the invention can also be provided to be foldable, as illustrated in Figures 15 to 21 in a first embodiment.

Thus, a foldable extension wheel 15 according to the invention comprises eight rim segments 150-157 all connected to an inner circular part 16 provided with a strapping part 152 comprising a clamping lever 152'. Thus, each rim segment 150.151 is connected to the inner circular part 152 by a first spoke 1501.1511 fixed freely in radial rotation at a first end of the rim segment and by a second spoke 1502.1512 also fixed freely in radial rotation at a second end of said rim segment. Each spoke is also fixed to the inner circular part freely in radial rotation.

Each spoke 1501,1511; 1502,1512 has a first end 1505,1515,1506, 1516 for connection to its corresponding rim segment 150.151, a main section and a second end 1504,1514,1503,1513 for connection to the circular part interior 152.

Each rim segment 150 thus has two spokes 1501, 1502 whose connecting ends 1507, 1508 are diametrically opposite on the inner circular part 16. With reference to FIG. 18a, each rim segment 151 provided with its spokes 1511, 1512 is provided with a tread segment 251 which can move freely. When the rim 15 is completely deployed, the various tread segments (partially represented in FIG. 18) 250, 251, 257 can then be moved in rotation within the rim 15 by an angle equal to 2.π/16 relative to their initial position in folded mode, so as to provide locking of the rim 16.

Foldable extension wheels 15.1, 15.2 of the type just described, each provided with an inner circular part 16.1, 16.2 can be implemented to equip a wheelchair (not shown), with reference to Figure 18b . They can be folded, as shown in figures 19 to 21.

In the folding phase, for each extension wheel, four rim segments, equipped with their non-consecutive treads 150.1, 152.1, 154.1, 156.1 are folded on one side of the inner circular part 16.1 while the other four rim segments 151.1, 153.1, 155.1, 157.1 which are not consecutive are folded on the other side of the inner circular part 16.1.

At the end of the bending phase, two sets S _A , S _B of non-consecutive rim segments have a diameter substantially less than or equal to that of the inner circular part 16.1, as illustrated in FIG. 21.

A description will now be given, with reference to FIGS. 22 to 26, of a second embodiment of a foldable extension wheel according to the invention. This extension wheel 215 comprises an inner circular part consisting of two inner circular parts 160a, 160b of identical diameter and axis and sliding relative to each other.

Each inner circular part (160a, 160b) is connected to a set of non-consecutive rim segments (250,252,254,256; 251,253,255,257) by curved spokes whose respective ends with a rim segment and the circular part are free in radial rotation.

The extension wheel 215 thus comprises two parts 215a, 215b, with reference to Figures 24a, 24b. Each wheel part 215a comprises four rim segments 250,252,254,256 connected to its inner circular part 160a via spokes of the same configuration as that which has been described with reference to figures 15 to 21 illustrating the first embodiment of an extension wheel foldable.

When the two sliding inner circular parts 160a, 160b are associated (Figure 25a+b (1)) and angularly offset (Figure 25(2)) by sliding one inner circular part relative to the other, then a extension wheel deployed (Figure 25(3)) from the eight rim segments 250-257. This extension wheel 215 can be folded with all the rim segments of the two rim parts 215a, 215b located on the same side of the inner circular part 160a, 160b, which contributes to a high level of compactness.

The extension wheels according to the invention can be made from metallic or composite materials usually used for the production of bicycle wheels and mobility systems.

The treads implemented in the initial wheels as in the extension wheels can be pneumatic or solid based on elastomer usually used in the cycle industry.

Of course, the present invention is not limited to the examples of implementation which have just been described and numerous variants can be envisaged.

Claims (28)

Extension wheel (1,1',1.1,1.2,18,136a,136b,137a,137b) comprising a rim (141,15) receiving a tread (140), and an inner circular part (2,2' ) coaxially connected to said rim (141) by a plurality of spokes (3), characterized in that the inner circular piece (2,2') comprises adjustable means (200) for removably enclosing an initial wheel (4, 5, 72.1, 72.2, 11.1, 11.2, 92.1, 92.2, 131a, 131b, 132a, 132b) of diameter smaller than that of said extension wheel (1,1', 1.1, 1.2, 136a, 136b, 137a, 137b ), so that the extension wheel (1,1',1.1,1.2,18,136a,136b,137a,137b) performs a rolling function and the initial wheel (4,5,72.1,72.2,11.1, 11.2, 92.1, 92.2, 131a, 131b, 132a, 132b) provides a hub function. Extension wheel (1) according to claim 1, implemented for the extension of an initial wheel (4,5) provided with a tread (40,50), characterized in that the adjustable means ( 200) include a strapping piece to enclose this tread (40,50). Extension wheel (1) according to claim 2, characterized in that the adjustable clamping means (200) comprise manually operable lever means (20). Extension wheel according to one of Claims 2 or 3, characterized in that the adjustable clamping means comprise means for axially locking the strapping part with respect to the tread of the initial wheel. Extension wheel according to one of Claims 2 to 4, characterized in that the strapping piece has patterns in relief on its inner face in contact with the tread of the initial wheel. Extension wheel (1') according to any one of the preceding claims, characterized in that it further comprises motorization means (201,202,203,204) arranged in the inner circular part (2') and in mechanical interaction with the wheel initial (4). Extension wheel (1') according to Claim 6, characterized in that the motorization means comprise a plurality of drive rollers (201,202,203,204) arranged between the inner circular part (2) and a tread (40) of the initial wheel (4). Extension wheel according to Claim 6, characterized in that the motorization means comprise an electromagnetic coupling system comprising a rotor part linked to the inner circular part and a stator part integrated into a rim of the initial wheel. Extension wheel according to one of Claims 6 to 8, characterized in that it also comprises energy storage means provided to supply the motorization means. Extension wheel according to claim 9, characterized in that the energy storage means are arranged in the inner circular part. Extension wheel (15,15.1,15.2) according to one of the preceding claims, characterized in that it is foldable. Extension wheel (18) according to Claim 11, characterized in that the rim (15) comprises rim segments (150-157) each provided with a tread segment (250,251) movable in rotation relative to the rim segments and means for locking the rim (15) such that adjacent rim segments (257,250,251) are locked. Extension wheel according to claim 12, characterized in that the locking means comprise magnetic locking means. Extension wheel (18) according to any one of Claims 12 to 13, characterized in that each rim segment (150) is connected to the inner circular part (16) by means of a first spoke (1501) and a second spoke (1502) having outer ends (1505,1504) connected to both ends of said rim segment (150) and inner ends connected to said inner circular piece (16) at two diametrically opposite points (1507,1508 ). Extension wheel (15.1, 15.2) according to claim 14, characterized in that it is arranged so that in folded mode, the rim segments are arranged on either side of the inner circular part (16.1, 16.2) into two sets (S _A , S _B ) of rim segments having a diameter substantially equal to or less than that of the inner circular part (16.1, 16.2). Extension wheel (15.1,15.2) according to claim 15, characterized in that each set of rim segments (S _A ,S _B ) comprises non-adjacent rim segments (150.1,152.1,154.1,156.1;151.1,153.1 ,155.1,157.1). Extension wheel (215) according to Claim 11, characterized in that the inner circular part is made in the form of two inner circular parts (160a, 160b) of identical diameter and axis and sliding relative to each other. the other, each inner circular part (160a, 160b) being connected to a set of non-consecutive rim segments (250,252,254,256; 251,253,255,257) by curved spokes whose respective ends with a rim segment and the circular part are free in rotation radial. Mobility system (6,7,9,9',9'',13) adapted to receive at least one extension wheel (1.1,1.2,136a,136b,137a,137b) according to any one of the preceding claims . Mobility system (6) according to Claim 18, of the wheelchair type, characterized in that it comprises a seat (62) and an axle fitted at its two ends with two initial wheels (11.1, 11.2) intended to be coupled to two extension wheels (1.1,1.2) according to any one of claims 1 to 16. Mobility system of the wheelchair type (6) according to claim 19, characterized in that the axis is equipped with a Segway (10) arranged under the seat (62) and comprising two directional actuators (14.1, 14.2) driving the two initial wheels (11.1,11.2) each coupled to an extension wheel (1.1,1.2). Mobility system of the wheelchair type (6) according to claim 20, characterized in that the two directional actuators (14.1, 14.2) of the Segway (10) are controlled by means of two armrests (61.1, 61.2) fitted to the wheelchair ( 6). Mobility system (13) according to claim 18, of the draisienne type comprising a frame (132) and two pairs of initial wheels (131a, 131b; 132a, 132b) parallel on two axes respectively front and rear (138, 139), characterized that this that the frame (132) is extensible and provided to receive extension wheels (136a, 136b; 137a, 137b) according to any one of claims 1 to 16 in coupling with the initial wheels (131a, 131b; 132a, 132b ). Mobility system (7) according to Claim 18, of the single-arm bicycle type comprising a frame (73) and two initial wheels (72.1, 72.2), characterized in that these two initial wheels (72.1, 72.2) are provided to receive two extension wheels (1.1,1.2) according to any one of claims 1 to 16. Mobility system (9,9',9'') according to claim 18, of the scooter type comprising a first rear part (B) built on a bicycle base and a rear wheel (90) and a second front part (A) comprising a base (94) and two front wheels (92.1) on a common front axle, characterized in that the two front wheels (92.1) are provided to receive two extension wheels (1.1) according to any one of claims 1 at 16. Triporteur-type mobility system (9) according to claim 24, characterized in that the rear wheel (92.2) is adapted to receive an extension wheel (1.2) according to any one of claims 1 to 16. Mobility system of the scooter type (9') according to one of Claims 24 or 25, characterized in that the front axle is motorized by means of a Segway (10) driving two initial wheels (92.1). Mobility system of the scooter type (9,9',9'') according to any one of Claims 24 to 26, characterized in that the rear part on the base of the bicycle (B) is detachable from the front part (A) . Mobility system of the scooter type (9', 9'') according to any one of Claims 24 to 27, characterized in that the front part (A) is provided to receive a compartment (12) for transporting people or a cargo module (97) or a wheelchair (6).