FR2941428A1 - Directive type one-piece running gear for use on rolling base of vehicle, has link, wheels and mechanism associated such that shaft is freely mounted for being automatically displaced in connecting movement by connection caused by link - Google Patents

Abstract

The gear (1) has two wheels (2), where each wheel is mounted to rotate around a rotary shaft (6) carried by a support (7). The wheels are kinematically connected together by an endless kinematic miming link (3). The link, the wheels and a spacer mechanism (13) are associated together so that the shaft is freely mounted in displacement and in a guided and dampened manner, on a predetermined course for being automatically displaced in spacing movement by the mechanism under the effect of pressure force on uneven ground (4) and in connecting movement by a connection caused by the link.

Description

1

The present invention relates to a unitary rolling train of a new type and a movable assembly comprising comprising, intended to be used in place of any other existing rolling element: wheel, wheel or the like. More particularly, the invention relates to a unitary rolling train formed by at least two rollers whose axes of rotation are displaceable away by means of at least one piece or a spacing mechanism and approaching by means of an endless kinematic linkage of the rolling belt type worn by the rollers. Conventional rolling trains do not offer sufficient comfort alone and when such comfort is desired, the rolling trains are generally associated with one or more suspensions. These suspensions are expensive and can not always be integrated directly into the rolling trains.

For mobile rolling units with one or more rolling trains, for example, wheeled furniture, trolleys and hospital beds, baby strollers, suitcases, etc., no suspension is generally provided. Thus, the rollers usually mounted on these mobile assemblies do not allow to roll satisfactorily on a soft, uneven or congested ground, for example by chippings. In addition, if they are used on rough, difficult, uneven or irregular surfaces, they generate uncomfortable, dangerous or even harmful vibrations that are transmitted to the rest of the moving assembly. These vibrations are very troublesome in that they are, for example, felt by the child sitting in the stroller, by the patient transported in his bed, or transmitted to objects placed on the wheeled furniture, which in the latter case , can 2

damage them by shocks or cause them to fall. In order to reduce these vibrations, it is known to fill the contact surfaces of the wheels and wheels with a tread of deformable flexible material. This solution is however only partially satisfactory, in particular because it results in premature wear of the tread in contact with the ground. In addition, conventional wheels and rollers tend to sink into soft ground, which makes their use quite difficult, especially on dirt floors, sand or the like. As a result, for vehicles usually traveling on this type of terrain, the wheels are replaced by tracks. Tracks have many disadvantages, including wear, reduced speed, high noise, and damaging road or ground damage. Finally, in the case of shopping trolleys for housewives, devil-type trolleys and similar moving mobile units, haulage trains are rarely adapted to obstacle clearance or the ascent and descent of stairs.

There is therefore the need for a means of taxiing that allows to circulate comfortably and quietly on any type of terrain and can be adapted to the descent and the rise of obstacles. A better driving comfort than that provided by conventional wheels and rollers is obtained thanks to the invention by means of a new unitary rolling train. This unitary rolling train comprises at least two wheels each mounted to rotate about an axis on a support. The axis of rotation of at least one of these rollers is displaceable away by means of a part or a spacer mechanism, the restoring force in position being 3

exerted by a kinematic link without end of rolling in particular of the belt type rolled by the rollers, the latter then being kinematically connected to each other by this rolling link. The running gear can be pivotally mounted or fixed on a rolling base serving as a frame for a moving assembly. Unlike conventional rolling mobile assemblies, the unit rolling train of the invention is not rolled directly on the outer periphery of the rollers, but on an endless kinematic link running carried by the at least two wheels of the train of rolling. Indeed, with this type of unitary rolling train, the bearing surface on the ground is more important and linear, and the user feels less uneven ground when rolling the movable assembly that is provided. In addition, in order to dampen the unevenness of the ground, the axis of rotation of at least one of the two wheels is movably mounted and guided, for example along a linear stroke along a substantially horizontal axis, for example along an elongated guide slot made in the flank pieces of the support on which are mounted the axes of rotation of the rollers. A spacer part or mechanism is mounted against the support to push at least one axis of rotation movable away when it is itself moved vertically upwards or downwards. the bottom under the weight of the moving mobile assembly on which he (she) is mounted (e), for example when it passes on uneven ground or a small obstacle, or it is shocked. The displacement of the axis of rotation of the wheel to the outside, provides a cushioning effect, the return to the initial position is naturally and

automatically by the elasticity of the tight link. In a preferred embodiment of the invention, provision is made for at least one intermediate rolling rest on the internal face of the kinematic rolling link, so as to improve the maintenance and the passage of the kinematic linkage of rolling between the rollers by an intermediate guide. and to maintain the kinematic link rolling on a rectilinear trajectory to prevent it from being deformed, for example in an undulating manner, following a rugged terrain. This intermediate rolling support is preferably made in the form of a roller or a cylindrical roller, smooth or grooved, for example smaller than the wheels and located between them. Its outer face or its groove can be supported on the kinematic link rolling where to be slightly recessed as shown in the figures.

Likewise, an outer surface with a semi-circular cross-sectional shape is preferably provided for the kinematic linkage of rolling, which provides ease in case of inclination of the unitary rolling train and makes it possible to reduce the contact surface, but also friction, between the kinematic link of rolling and the ground. Finally, it is possible to provide the volume of the rear face cut into regular transverse cuts on the internal face of the kinematic rolling link, in particular of the belt type, which allows an easier deformation thereof, providing a rolling and a return movement. easier and faster. Other features and advantages of the invention will appear on reading the detailed description which follows, description made with reference to the accompanying drawings, in which:

Figure 1 is an overall profile view of a unitary rolling train according to a preferred embodiment of the invention comprising two wheels; . Figure 2 is a vertical sectional view at a wheel of the unitary rolling train of Figure 1; Figure 3 is a vertical sectional view at an intermediate rolling support of the unitary rolling train of Figure 1; . Figure 4 is a dissociated overview of the unitary rolling train of Figure 1; . Figures 5 to 7 are schematic side views illustrating how the spacer moves the axes of rotation of two wheels; . Figures 8 to 13 are cross-sectional views between two rollers of the unitary rolling train according to the invention illustrating different variants for the section of the kinematic rolling link and the groove of the rollers; FIGS. 14 to 17 are side views of a section of the kinematic rolling link according to different variants of the invention in which the kinematic rolling link has an internal face which may or may not be cut into regular transverse cuts; . Figures 18 to 25 are schematic side views illustrating the descent of a staircase by a rolling assembly comprising two rolling trains according to the invention; Figures 26 to 31 are perspective views illustrating different variants for the spacer of the unitary rolling train according to the invention; . FIG. 32 is an overall profile view of a variant of the unitary rolling train according to the invention in which the axis of a single

caster is movably mounted by means of the spacer; . FIG. 33 is an overall profile view of a variant of the unitary rolling train according to the invention in which the rolling train comprises four aligned rollers, the axes of the end rollers being movable by means of the workpiece of FIG. spacing; FIG. 34 is an overall profile view of a variant of the unitary rolling train according to the invention in which the rolling train comprises three aligned rollers, the axes of the end rollers being movable by means of the workpiece of FIG. spacing and the flank pieces of the support each having two elongated slots substantially vertical; . FIG. 35 is an overall profile view of a variant of the unitary rolling train according to the invention in which a third fixed-axis wheel is mounted above the two other wheels with displaceable axis; and. FIG. 36 is an overall profile view of a variant of the unitary rolling train according to the invention, which rolling train comprises three rollers, each of the axes of which can be moved away by means of a spacer common. The unitary rolling train according to the present invention will now be described in detail with reference to FIGS. 1 to 36. The equivalent elements represented in the different figures will bear the same numerical references. The variants shown in the figures are given by way of example only and should not be interpreted restrictively. For the sake of simplification, most of the figures represent a unitary rolling train according to a method of

preferred embodiment of the invention. Several variants are however possible for the invention. Similarly, the number of elements, such as, for example, the wheels, the shape of the means and their positions should not be interpreted restrictively. Thus, although for the invention we are limited to the use of two to four wheels, it may be envisaged to incorporate a larger number in the same unitary rolling train. Likewise, any number of rolling unit trains of the invention may be mounted on the same mobile moving assembly. In general, the invention relates to a unitary rolling train 1 of a new type as shown in Figures 1 to 4 in its simplest variant. This unitary rolling train 1 is intended to be used instead of any other existing rolling element: wheel, wheel or the like. It comprises at least two rollers 2 on which a rolling kinematic link 3 rolls. At least two rollers 2 are mounted, each aligned in rotation about an axis 4 carried by a support 5. The rotation axis 4, 6 at least one of the end rollers 2, 7, that is to say the front and rear rollers 2, 7, is movably mounted in operation in a substantially horizontal linear stroke, for example along a slot elongated guide 8 made in the side pieces 9 of the support 5 on which are mounted the rotation axes 4 of the rollers 2. In Figures 1 to 4, there is shown a preferred embodiment of the invention wherein the axis of rotation 4, 6 of the two end rollers 2, 7 is mounted movable in operation.

By axis of rotation displaceable during operation, it is meant an axis of rotation which can move automatically in translation during

the use of the moving mobile assembly on which it is mounted, as opposed to an axis of rotation that is moved during an adjustment, for example during the adjustment of the tension of the rolling link 3.

Generally, such an adjustment is carried out before the use of the moving mobile assembly by displacement after unscrewing a screw or a screw-nut assembly and ends after screwing to a fixed position of the axis of rotation or rotation. rolling. In the invention, the axes of rotation are free, that is to say that they move automatically in operation at any moment under the effect of a force coming from a pressure on the running gear and back to the initial position by elastic return.

The support 5 on which the rolling axles are mounted is preferably constituted by two flank pieces 9 assembled and held parallel at a fixed distance from one another by suitable connecting means 10, 11.

According to a not shown variant of the invention, the support 5 may also be in one piece, for example in the form of an inverted U-shaped metal plate, the two lateral faces of which form its sidewalls 9.

According to a preferred embodiment of the invention, the assembly means 10, 11 of the sidewall parts comprise horizontal transverse rods 10 which are immobilized between the sidewalls of the support, for example by screwing, welding or stamping. In a preferred embodiment of the invention, provision is made for at least one intermediate rolling rest 12 on or in the immediate vicinity of the inner face 13 of the kinematic rolling link 3 in its lower and / or upper part, intermediate rolling rest 12 which facilitates the passage of the kinematic link rolling 3 between the wheels 2 and 9

to keep it on a straight path. This rolling support 12 is for example in the form of at least one roller 14 disposed between two rollers 2 in the transverse position relative to the kinematic link rolling 3 or mounted in transverse displacement with respect to this kinematic link rolling 3. This displacement can be damped by an elastic force provided by a spring (not shown). The axis of rotation of this roller 14 is then guided along two parallel transverse and parallel lights. According to this preferred variant, the rolling supports 12 can be mounted on the transverse rods 10 which hold the flank pieces 9 of the support 5 at a fixed distance. It is possible to envisage various variants not shown and according to which the vertical position of one or several rolling supports 12 may be variable and indexable by means of a suitable device, for example by means of a screw sliding freely in a slot after loosening of a nut mounted thereto (not shown). According to another variant of the invention, the vertical position of a rolling rest 12 may be adjustable or occasionally displaceable by means of a mechanical device that can be controlled, for example by means of a hydraulic jack (not shown ) in order to make a point contact point useful in the maneuvers. It is also possible to mount the axis of rotation of the rolling support in elastic suspension along a guide slot. Finally, it is also conceivable to mount one or more rolling bearings 12 on an elastic thrust device, for example a spring, which elastically constrains these rolling bearings 12 on the internal face 13 of the endless kinematic link.

3. Changing the vertical position of a rolling support 12 advantageously allows to spatially deform the shape of the perimeter of the kinematic rolling link 3, for example in order to minimize the friction surface between this link 3 and the ground 15. Thus the bearing zone may serve as a pivot point, for example to facilitate the pivoting of the unitary rolling train 1 on itself.

It is conceivable according to an improved variant not shown, to secure the means of displacement of or a support roller 14 to the means causing the spacing of the axes of the rollers. In each of its flank pieces 9, the support 5 preferably has at least one elongate guide slot 16, for example substantially vertical, along which a substantially horizontal connecting axis 17 is displaceably mounted. On this connecting axis 17 is mounted at least one piece or a spacer mechanism 18, preferably two, and on either side of the end rollers 2, 7. When it is moved (e) vertically upwards or downwards, this (e) part or spacer mechanism 18 is provided (e) to push at least one axis of rotation movable 4, 6 away. According to the invention, the part or the spreading mechanism 18 is provided for pushing apart the axes of rotation 4, 6 of the end rollers 2, 7 movably mounted along an elongated slot 8 made in FIG. the flank parts 9 of the support 5. The movement of the at least one rolling support 12 may be indexed by means of a suitable device 35 motor or not or be associated with the control movement of the part or the spacing mechanism 18. An example of how the coin or

distance mechanism 18 removes the axes of rotation of two rollers 2 during its vertical displacement is shown schematically in Figures 5 to 7. According to a preferred embodiment, the spacer 18 is shaped as a vertical plate 19 whose longitudinal extensions each have a cutout 20 at their end, this cutout 20 being preferably shaped in V whose branches are respectively oriented outwardly so as to engage in the hollow of the V the axes of rotation 4, 6 of the end rollers 2, 7 mounted movable. Thus, when the spacer 18, 19 moves vertically downwards (FIG. 6) or upwards (FIG. 7), the segments of its cuts 20 act as a motion conversion ramp by pressing the axes. rotating 4, 6 movable wheels 2, 7 to move them away from each other. This distance being guided horizontally by the guide slots 8 made in the flank pieces 9 of the support 5. When the spacer 18, for example in the form of plates 19, is no longer biased in vertical displacement, the return in the initial position (FIG. 5) is carried out automatically by the elastic restoring force coming from the kinematic rolling link 3 stretched over the rollers 2. It is perfectly possible to envisage another means making it possible to move the axes of rotation 4, 6 away from the rollers The spacing mechanism 18 may, for example, comprise a link mechanism or the like (not shown) or any other motion conversion means for moving the axes of rotation 4, 6 away from the caster wheels. end 2, 7 when it is subjected to a particularly vertical support force.

It will be noted that it is the tension alone of the kinematic rolling link 3 which automatically recalls the axes of rotation 4, 6 of the displaceable rollers 2,

7 towards each other. Thus, in the normal position of use, these pins 4, 6 come into abutment against the portion of the guide slots 8 near the center of the side pieces 9 of the support 5, for example in the immediate vicinity of the tip of the V of each blank 20. Although in the figures there is shown a part or a spacing mechanism 18 located on each side of the unitary rolling train 1 outside the sidewalls 9 of the support 5 and against these, it is perfectly possible to envisage mounting each of these parts or spacer mechanisms 18 on each side of the unitary rolling train 1 between the displaceable rollers 2, 7 and the sidewalls 9 of the support 5.

It is recalled here that one can subject the movement of the support roller 14 to that of the spacing of the axes of the rollers. As shown in the various figures, the new type of unitary rolling train 1 according to the invention is based on the use of a kinematic rolling link 3 carried rolling by the rollers 2. The outer surface 21 of this link kinematic rolling 3 preferably has a substantially semicylindrical shape, namely a shape of substantially semicircular section. Thus, while having a sufficient length to mitigate shocks caused by the presence of small obstacles or imperfections of the ground, the use of a kinematic rolling link 3 of this type considerably reduces the friction surface between the kinematic link rolling 3 and the ground 15, which results in greater ease of movement for a mobile assembly 22 equipped with unit trains rolling 1 according to the invention.

The kinematic link of rolling 3 can also have a total curvilinear section, for example round or oval, of which a fraction of surface - so-called

outer surface 21 - is in contact with the ground 15 and allows different incidences with the ground 15, the other - said inner surface 13 - bearing bearing on the outer face 23 of each wheel 2. For this purpose, the wheels 2 are preferably casters 2 with groove, each groove having a section whose shape corresponds to that of the inner surface 13 of the kinematic linkage of rolling 3. In order to avoid that the kinematic link rolling 3 particular belt type does not sort of the groove of the rollers 2 or an intermediate rolling support 12, especially in the event of significant lateral force on it, the inner surface 13 of the kinematic rolling link 3, namely the surface in contact with the rollers 2, can have a substantially semicircular, trapezoidal, triangular, square, rectangular or other sectional shape. Various examples of section shapes for the inner surface of the kinematic rolling link 3 are shown in FIGS. 8 to 10, in which the outer surface 21 of the kinematic rolling link 3 has a shape of substantially semicircular or otherwise convex section. As shown in FIGS. 11 to 13, the outer surface 21 of the kinematic rolling link 3 may also have a section of radius greater than that of the inner surface 13, so that the substantially hemicylindrical shape of the surface of the rolling 21 has a flange resting on the periphery of the lateral faces of the rollers 2. According to these different variants, the rollers 2 preferably have, although not necessarily, an external profile complementary to that of the inner surface 13 of the kinematic rolling link 3 According to another variant of the invention, the inner surface 13 of the rolling kinematic link 3,

may be full (FIG. 14) or may have notches 24 (FIGS. 15 to 17), preferably transverse and regular, the depth of which permits a faster and much quieter rotation and deformation of the kinematic linkage of rolling 3. Indeed, these notches 24 also increase the overall flexibility of the kinematic link rolling 3 belt type and promote its ability to bend without using a softer material and therefore less resistant to wear. These cuts 24 may have different shapes, including a rectangular profile (Figure 15), trapezoidal (Figure 16) or triangular (Figure 17).

Thanks to the invention, it is possible to use a relatively hard running kinematic link 3 which does not need to have a higher plasticity. It is preferably made of polymeric material, and advantageously has a central wire frame 25. When at least one unitary rolling train 1 of the invention is mounted on a movable moving assembly 22, it can be fixed thereto by the intermediate of the substantially horizontal connecting pin 17 which is movably mounted in the substantially vertical elongate guide slot 16 formed in each of the flank pieces 9 of the support 5. Thus, in case of shock or unevenness of the ground, the piece or the spacing mechanism 18 which is mounted on the connecting pin 17 is moved (e) vertically upwards or downwards under the bearing force on the ground of the movable assembly 22 on which the unitary rolling train 1 of the invention is mounted. The displacement of the axis of rotation 4, 6 of each displaceable wheel 2, 7 towards the outside brings a damping effect, whose return to the initial position is effected automatically by

the elasticity of the tensioned connection 3. In the case where the part or the spacer mechanism 18 is in the form of a plate spacer 19 with V end cutouts 20, this damping effect is in principle proportional to the opening angle of the V of the cutout 20 made in the spacer part 18 in plate 19. The greater the angle of the V is open, the greater the distance away from the displaceable rollers 2, 7 is weak and the damping effect will be weak (soft damping). On the contrary, the more the angle of the V is closed, the greater the amplitude of the distance of the movable wheels 2, 7 and the greater the damping effect will be important (hard damping).

FIGS. 26 to 28 show examples of spacers 18 having cutouts 20 with different angle openings. The opening angle of the V of the cutout 20 made in the spacer 18 is preferably between 60 ° and 160 °, more preferably between 100 ° and 130 °. As shown in Figure 26, according to a preferred embodiment, the opening angle of the V of the cutout 20 formed in the spacer 18 is substantially equal to 120 °. Although only the cutout 20 formed in the V-shaped spacing piece 18 has been shown, this cutout 20 may have any other adapted shape, which allows the spacer 18 to move the axes of rotation away from each other. 4, 6 movable rollers 2, 7. Thus, the angular portion of the V may be rounded, as shown in Figure 29. Similarly, the cutout 20 may be fully rounded (Figure 30), which allows for example to provide a progressive damping effect. In the same vein, cutting 20

is not necessarily symmetrical. If this cutout 20 is asymmetrical (Figure 31) it then provides a different damping effect depending on whether the spacer 18 is moved up or down. The substantially horizontal connecting shaft 17 which is displaceably mounted in the substantially vertical elongated guide slot 16 formed in each of the sidewall parts 9 of the support 5 and which makes it possible to fix the unitary rolling train 1 on a mobile moving assembly 22, can be pivotally mounted or fixed on a moving assembly 22 to form a rolling base 26. In the case where this substantially horizontal connecting shaft 17 is pivotally mounted on a moving assembly 22, the unitary rolling train 1 of the invention can pivot around this axis 17. This allows for example to easily move the mobile assembly 22 on a sloping ground or to negotiate a difficult passage, for example when the ground 15 is congested by pebbles or other obstacles. Advantageously, the pivoting mounting of the unitary rolling train 1 of the invention can also make it possible to go up or down a staircase. By way of example, in FIGS. 12 to 19, the descent of a step is shown by a commission carriage 22 equipped with a pair of pivoting rolling trains 1 of the invention. The advantages of such a pivotal mounting for the unitary rolling train 1 of the invention are numerous and those given here are only examples.

The tension of the endless kinematic linkage 3 keeps each axis of rotation displaceable 4, 6 towards the center of the unitary rolling train 1 in the elongated guide slot 8 and exerts an elastic force of resistance and return during its moving away. Thus, the sliding axis of rotation 4, 6 of each caster 2, 7 slidably mounted can be

with an elastic suspension effect without the need to use another means for obtaining an elastic return, such as by springs or the like. This damping effect, increased by the antivibration nature of the kinematic link rolling 3, ensures inter alia, great strength for all and an increased life for the bearings of the rollers 2. It will be noted that the greater the weight exerted on the part or the spacing mechanism 18 is important, the more the tension of the kinematic link rolling 3 is strong. It is therefore a damping effect adapting itself to the weight of the movable assembly 22 on which it is mounted.

The preferred embodiment of the invention is shown in FIGS. 1 to 4. However, numerous variants can be envisaged for a unitary rolling train 1 whose axis 4 of at least one of the rollers 2 is movably and movably mounted. away in the action of the vertical movement of a part or a spacer mechanism 18. Thus, in Figure 32 has been shown a variant of the rolling train 1 of the invention in which the axis of rotation 4, 6 of a single wheel 2, 7 is movably mounted and movable away. One can also consider a rolling train 1 having more than two rollers 2, aligned or not. Thus, in Figure 33, there is shown a variant of the rolling train 1 of the invention comprising four wheels 2 aligned and wherein the axis of rotation 4, 6 of the front and rear wheels 2, 7 is movably mounted and movable away under the action of the vertical displacement of a part or a spreading mechanism 18.

Similarly, in the case where the rolling train 1 comprises more than two rollers 2, these rollers 2 are not necessarily aligned. We will nevertheless note

that the rollers 2 of the same unit train must generally be located in the same plane to receive a kinematic link endless rolling 3 rolled by them.

In addition, regardless of the number of rollers 2 that counts the rolling train 1, the sidewall pieces 9 of the support 5 may each have any number of substantially vertical slots 16. When this number is greater than one, these slots 16 provide a better guidance for the vertical sliding of the spacer 18. By way of example, in FIG. 34 there is shown a rolling train 1 comprising three rollers 2 aligned with the sidewall pieces 9 of the support 5 having each two vertical slots 16 for better vertical guidance of the spacer 18. In Figure 35 there is shown a rolling train 1 having three wheels 2 arranged vertically in a triangle, the two wheels 2, 7 of the bottom being substantially similar to those of the rolling gear 1 shown in Figures 1 to 4, while the third roller 2, namely that of the top, is rotatably mounted about a fixed axis above those -this. In this figure, the third wheel 2 is shown in the central position relative to the other wheels 2, 7, but this is not mandatory. According to this variant, the endless kinematic link rolling 3 rolled by the three rollers 2 undergoes a lower bending movement of the movement than when it is carried by two rollers 2. This reduces the torsional forces exerted on it. ci and considerably facilitates the passage of the rolling link 3 around the rollers 2. According to this variant, if the substantially horizontal connecting pin 17 mounted on the part or the spacer mechanism 18 is pivotally attached to a moving mobile assembly 22

the whole of the rolling train 1 can freely pivot about this axis 17. Nevertheless, because of the low position of the connecting pin 17 in this variant, the position represented in FIG. 35 for the rolling train 1 is that corresponding to the equilibrium position, to which the rolling train 1 automatically returns after a pivoting movement on itself, for example in the case of a step. Note that this low position for the connecting axis 17 is not mandatory and that it can be located substantially anywhere within the perimeter defined by the axis of rotation of the three wheels 2. In the figure 36, there is shown a rolling train 1 having three rollers 2 arranged vertically in a triangle, the axis of rotation 4, 6 of each of these rollers 2, 7 being movably mounted and movable away from each other by the action of the vertical displacement of the same part or the same spacing mechanism 18 substantially central (e). According to this variant, the substantially horizontal connecting shaft 17 mounted on the part or the spacer mechanism 18 is pivotally attached to a mobile moving assembly 22. The rolling train 1 being symmetrical about an axis of rotation of 2rr / 3, the connecting pin 17 is mounted substantially central relative to the entire rolling gear 1 so that after pivoting on itself 2rr / 3, the rolling train 1 is found in an equivalent position. According to this variant, the elongated guide slot 16 made in the flank pieces of the support has an additional branch, so as to form a three-pointed star conformation. As explained above, the unitary rolling train 1 of the invention can be mounted on any moving assembly 22 instead of existing rollers 2 on it to constitute

a rolling assembly or a rolling base 26. Thus, the invention also relates to any mobile rolling assembly 26 comprising a chassis supported by rolling means including at least one unitary rolling train 1 according to the invention, at least one train rolling 1 can be directive. It can also be applied to all movable or movable furniture usually mounted on wheels, be it indoor furniture, trolleys or hospital beds, carts, chairs, armchairs, tables , workbenches, etc. Finally, the application of the invention has no limit and can be applied to any mobile assembly 22 usually comprising wheels: supermarket trolley, toy, stroller, robot, gantry, suitcase, scaffolding, etc. . It concerns all fields, and more particularly that of transport, furniture, catering, health, agriculture and mechanics in general. Resistant, quiet and comfortable on any type of terrain, the unit rolling train 1 of the invention is a new type of rolling means that provides a significant improvement in the state of the art. Obviously, the invention is not limited to the preferred embodiment described above and shown in the various figures, the skilled person can make many changes and imagine other variants without leaving the scope or of the scope of the invention. Thus, for example, it is possible to envisage a further improvement which consists in indexing the position of at least one of the elongated guide slots 8 made in the flank pieces 9 of the support 5. This indexing can be effected by means of a mechanism quick adjustment, practical and inexpensive, for example

in known manner by means of a substantially horizontal sliding piece, having an elongate guide slot and being immobilizable against the flank pieces 9 of the support 5, the elongate guide slot of this part covering all or part of a guide slot elongated 8 longer made in the flank pieces 9 of the support 5. Similarly, although in the various figures there is shown a unit rolling train 1 having a single kinematic link without end of rolling 3, we can perfectly consider a train rolling unit 1 comprising two or more, for example by combining several unit rolling trains 1 according to the invention. In this case, the driving kinematic links 3 can be aligned one behind the other, or be located substantially at the same level, parallel to each other.

Claims (28)

REVENDICATIONS1. Unitary rolling train (1) comprising at least two rollers (2) aligned and each rotatably mounted about an axis (4) carried by a support (5) having flank pieces (9) assembled and held parallel to each other by suitable connecting means (10, 11) or in the form of a single U-shaped piece or any other suitable support, these rollers (2) being kinematically connected to each other by an endlessly kinematic link (3) having an inner face (13) in contact with at least two rollers (2) and an outer face (21) in contact with the ground (15), so that the unitary rolling train (1) rolls on the rolling kinematic link (3) carried by the at least two rollers (2), characterized in that the axis of rotation (4, 6) of at least one of the end rollers (2, 7) is movable away from the means of at least one piece or a spacing mechanism (18), and approaching by the kinematic link endless rolling (3) rolled by the rollers (2). 2. unitary rolling train according to claim 1, characterized in that the at least one piece or a spacer mechanism (18) is provided (e) for moving at least one movable axis of rotation (4, 6) d a wheel away from the other axis of rotation when this part or this spacer mechanism (18) is actuated (e) by a force. 3. Unit rolling train according to the preceding claim characterized in that the actuating force comes from the support of the unitary train on the ground. 4. unitary rolling train according to claim 1, characterized in that the movable axis of rotation (4, 6) of at least one of the end rollers (2, 7) is movably mounted enfôttionnement in a linear stroke the along an elongated guide slot (8) formed in the parts of the support (5). 5. unitary rolling train according to the preceding claim, characterized in that the elongated guide slot (8) is horizontal, that is to say parallel to the straight portion of the kinematic link. 6. Unit rolling train according to claim 1, characterized in that it comprises two end rollers (2, 7), the axes of rotation (4, 6) of which are displaceably movable in operation by the movement of a spacer or by a spacer mechanism (18) both actuated by a biasing device. ground support of the unitary rolling train. 7. Unit rolling train according to claim 1, characterized in that it comprises, arranged between two wheels, at least one intermediate wheel bearing (12) on or in the immediate vicinity of the inner face (13) of the kinematic link rolling (3) in its lower part and / or in the form of at least one rolling element of the type roller (14) or other, fixed, movable or adjustable in transverse position relative to the kinematic link rolling (3). 8. Unit rolling train according to the preceding claim, characterized in that the displacement of the rolling support (12) is mounted on an elastic force pushing device which forces elastically on the inner face (13) of the kinematic link without end of running (3). 9. Unit rolling train according to claim 7, characterized in that the movement of the at least one rolling support (12) is indexed by means of a motor or non-motor adapted device or is associated with the control movement of the part. or the spacer mechanism (18). 10. Unit rolling train according to claim 7, characterized in that the support (5) has in each of its side pieces (9), at least one elongated guide slot (16) in which a connecting pin (17) ) is mounted displaceable transversely to the whole unitary rolling train, this connecting axis receiving at least one spacer or a spacer mechanism or connecting them to each other or to each other. 11. unitary rolling train according to claim 10, characterized in that two parts or spacing mechanisms (18) are mounted (e) s on the connecting pin (17) on either side of the wheels of end (2, 7). 12. Unit rolling train according to claim 1, characterized in that the spacer (18) is a spacer formed into a plate (19) whose longitudinal extensions each have a cutout (20) at their end, this cutout (20) being provided to engage the axes of rotation (4, 6) of the end rollers (2, 7) and move them relative to each other by an oblique ramp effect during the relative movement the spacer (18) with respect to the support (5). 13. Unit rolling train according to the preceding claim, characterized in that the cutout (20) is shaped V whose branches are respectively oriented outwardly so as to engage in the hollow of the V in a rest position axes movable rotation (4, 6) of the end rollers (2, 7). 14. Unit rolling train according to the preceding claim, characterized in that the opening angle of the V of the blank (20) is between 60 ° and 160 ° and preferably equal to 120 °. 15. Unit rolling train according to claim 12, characterized in that the partierectiligne and the angular portion of the cutout (20) V are rounded. 16. Unit rolling train according to claim 1, characterized in that the part or the spacer mechanism (18) comprises a rod-type motion-converter mechanism or other means enabling the axes of rotation (4, 6) to be moved away from each other. ) end casters (2, 7) when this motion-converting mechanism is subjected to a force from the ground support. 17. Unit rolling train according to claim 1, characterized in that the kinematic rolling link (3) has a total section of semicircular or curvilinear shape and in that the rollers (2) are rollers (2) to groove, each groove having a section whose shape corresponds to that of the inner surface (13) of the kinematic rolling link (3). 18. Unit rolling train according to claim 1 or 17, characterized in that the inner surface (13) of the rolling kinematic link (3) has a substantially semi-circular, trapezoidal, triangular, square or rectangular cross sectional shape. 19. Unit rolling train according to claim 1, characterized in that the outer surface (21) of the kinematic rolling link (3) has a circular or curvilinear section with a radius greater than that of the inner surface (13). 20. Unit rolling train according to claim 1, characterized in that the inner surface (13) of the kinematic rolling link (3) has cuts (24) transverse and regular. 21. Unit rolling train according to claim 1, characterized in that it is mounted alone or in plurality, fixed or pivoting about a vertical axis 35 or vertical on a movable assembly (22). 22. Unit rolling train according to claims 10 or 11 characterized in that it is mounted on a movable assembly (22) and fixed on the latter through the connecting pin (17). 23. Unit rolling train according to claim 1 comprising three wheels (2) arranged vertically in a triangle, characterized in that the axes of rotation (4, 6) of the two wheels (2, 7) of the bottom are mounted movable away from under the action of the displacement of a part or a spacer mechanism (18), while the third wheel (2), namely that of the top, is rotatably mounted about a fixed axis above those -this. 24. Unit rolling train according to claim 1 comprising three wheels (2) arranged vertically in a triangle, characterized in that the axis of rotation (4, 6) of each of these wheels (2, 7) is movably mounted and movable away under the action of the displacement of the same part or the same spacing mechanism (18) substantially central (e). 25. Unitary rolling train according to claim 4, characterized in that the position of at least one of the elongated guide slots (8) formed in the side pieces (9) of the support (5) is indexed by means of a quick adjustment mechanism. 26. Unit rolling train according to the preceding claim, characterized in that the position of at least one of the elongated guide slots (8) is indexed by means of a horizontal sliding part, having an elongate guide slot and immobilized against the side pieces (9) of the support (5) with the elongate guide slot of this piece covering all or part of a longer elongated guide slot (8) made in the flank pieces (9) of the support (5). 27. Unit rolling train according to any one of the preceding claims, comprising two endless rolling kinematic links (3) or more, each carrying at least two wheels, aligned one behind the other or located at the same level. , parallel to each other. 28. Rolling mobile assembly (26) comprising a frame, characterized in that this frame is supported by at least two rolling unit trains (1) according to any one of the preceding claims, at least one of which can be director.