A wheeled vehicle for transporting people designed to climb stairs.

Abstract

The invention relates to a wheeled vehicle for transporting persons, the wheeled vehicle (1, 301, 401) being a child's stroller or a wheelchair. The propulsion system of the vehicle comprises, among other things, two front wheels (2, 302, 402), two rear wheels (3, 303, 403), and at least one electric motor (22, 322, 422). Each of the two front wheels (2, 302, 402) has a rigid front rim (2J, 302J, 402J) and a deformable front rolling element (2P, 302P, 402P) arranged around the front rim (2J, 302J, 402J). Said at least one electric motor (22, 322, 422) is configured to provide a rotational drive to one of the front rims (2J, 302J) and the rear rims (3J, 303J, 403J). The propulsion system further includes a transmission assembly (21, 321, 421). Figure for the abbreviation: Figure 1

Description

Title of the invention: Rolling vehicle for transporting people designed to climb stairs. Technical field

[0001] The present invention relates to a rolling vehicle for transporting persons.

[0002] The term "rolling vehicle for transporting persons" means a vehicle comprising a A seat for one person and wheels that allow the wheeled device to move. This can be a stroller for a child, with one or more seats, or a wheelchair, for a child or an adult. Technological background

[0003] Such rolling machines are generally only suitable for rolling on flat or nearly flat surfaces with little or no incline. Some places are equipped with specific facilities such as access ramps to provide such surfaces, but many other places are not, which forces the rolling machine to climb a staircase.

[0004] However, a staircase, even one with only a few steps, can represent a difficult obstacle for the device to climb. In particular, for a person pushing a stroller, a staircase (in a subway station or stairwell, for example) can be difficult to climb without the help of another person.

[0005] To attempt to solve this problem, CN 211918803 U describes a child's stroller in which each of the two rear wheels is equipped with an electric disc motor, and each of the two front wheels consists of five casters mounted on a common rotating frame. However, in practice, such a stroller can only climb stairs if the person pushing the stroller exerts pressure by pushing down on the rear of the stroller to increase the traction of the rear wheels. Without action from the person pushing the stroller, the stroller is unable to climb stairs, unless the electric disc motor is very powerful and the rear wheels are similar to quad or motocross wheels, which would make the stroller excessively heavy.

[0006] Another solution is proposed in CN 207631319 U, which describes a child's stroller in which each of the two front wheels consists of three casters mounted on a common rotating frame, and in which the two rotating frames are mounted on a common shaft driven by a single electric motor. However, in practice, the front wheels easily cross the first step of the staircase, but without action from the person pushing the stroller, the stroller struggles to climb the following steps. Moreover, the stroller The disadvantage is that, when the electric motor is powered, the front wheels, consisting of three casters mounted on a common rotating frame, generate a jolt each time one of the casters comes into contact with the ground or a step, which is uncomfortable for the child. Summary of the invention

[0007] The invention aims to provide a rolling vehicle for transporting people which is capable of safely climbing a staircase while minimizing jolts that cause discomfort for the person sitting in the vehicle.

[0008] For this purpose, the invention proposes a rolling device for transporting persons, the rolling device being a stroller for a child or a wheelchair and the rolling device comprising a chassis which supports a seat for a person and a propulsion system to propel the chassis, the propulsion system comprising: - wheels enabling the chassis to roll on the ground, the wheels comprising two front wheels and two rear wheels; - at least one electric motor; and - an on-board power source to supply electricity to at least one electric motor, in which each of the two front wheels comprises a rigid front rim and a deformable front rolling element arranged around the front rim, in which each of the two rear wheels comprises a rigid rear rim and a deformable rear rolling element arranged around the rear rim, in which said at least one electric motor is configured to effect a rotational drive of one of the front rims and the rear rims, and the propulsion system further comprises a transmission assembly configured so that said rotational drive drives the other of the front rims and the rear rims.

[0009] Such a wheeled device is capable of climbing a staircase safely and without any action from the person pushing the device or the person sitting in it (except to activate the propulsion system), thanks to the combination of two factors: the deformability of the front and rear rolling elements on the one hand, and the presence of the transmission assembly on the other. It is only necessary that at least one electric motor deliver sufficient torque. Indeed, when the front wheels are about to cross a step, the deformability of the front rolling elements ensures that the front wheels can cross the step, thanks to the torque supplied by at least one electric motor and through a local deformation of the front rolling elements; and on the other hand, torque is also supplied to the rear wheels, which further assists the device. rolling to cross the stair steps, and the deformable nature of the rear rolling elements prevents the rear wheels from slipping and allows the rear wheels to cross a stair step in turn.

[0010] In fact, due to the presence of the transmission assembly, both front wheels and both rear wheels are driven; in other words, all four wheels are driven. The vehicle according to the invention is, however, different from a vehicle where each wheel is driven by a separate electric motor: either said at least one electric motor drives the rear rims in rotation, and this rotation drives the front rims, or said at least one electric motor drives the front rims in rotation, and this rotation drives the rear rims.

[0011] Finally, since the front and rear wheels are not made up of casters mounted on a common rotating frame, there is no jolt each time one of the casters makes contact with the ground or a stair step. On the contrary, the deformable nature of the front and rear rolling elements tends to absorb any shock due to an irregularity in the vehicle's path, such as a stair step. The vehicle therefore minimizes jolts that cause discomfort for the person seated in it.

[0012] In certain embodiments, said at least one electric motor is configured to perform a rotational drive of the front rims and the transmission assembly is configured so that said rotational drive drives the rear rims.

[0013] This possibility is considered preferred within the scope of the invention, because the torque delivered by at least one electric motor is then supplied first to the front wheels, which helps the front wheels to climb a step. When an electric motor is provided for each front wheel, it may be sufficient for these electric motors to have a power output of 1.0 kW each. Of course, the power of the electric motor(s) can be different (and in particular higher), especially depending on the expected total weight of the vehicle. For example, if an electric motor is provided for each front wheel, these electric motors could each be 1.5 kW, 2 kW, or 3 kW.

[0014] In some embodiments, the on-board power source includes a battery, preferably a lithium-ion battery.

[0015] In some embodiments, the propulsion system comprises a single electric motor configured to drive the front rims of the two front wheels. In some embodiments, the transmission assembly includes a front differential and a rear differential, the front differential being driven by the single electric motor and driving the front rims of the two front wheels, the rear differential being driven by the front differential and driving the rear rims of the two rear wheels.

[0016] In some embodiments, the propulsion system comprises two electric motors, each of the two electric motors being configured to achieve a rotational drive of the front rim of one of the front wheels, and the transmission assembly being configured so that the rotational drive of the front rim of one of the front wheels drives the rear rim of one of the rear wheels.

[0017] In some embodiments, the transmission assembly does not include a clutch between the electric motors and the front wheels. This considerably simplifies and lightens the transmission assembly. Such clutches are not necessary in any case, since the deformable rolling elements tend to absorb any shock due to an irregularity in the vehicle's path, whether the electric motors are powered or not.

[0018] In some embodiments, the transmission assembly includes two front pulleys each coupled to the front rim of one of the front wheels, two rear pulleys each coupled to the rear rim of one of the rear wheels, and two continuous drive elements each wound around a front pulley and a rear pulley, the two continuous drive elements each comprising a chain, a toothed belt or a smooth belt, and each of the two electric motors being arranged to drive one of the front pulleys.

[0019] In some embodiments, the chassis comprises two housing elements, each of the housing elements surrounding at least partially one of the two continuous drive elements.

[0020] In certain embodiments, each of the two electric motors drives one of the front pulleys via an auxiliary continuous drive element, the auxiliary continuous drive element preferably comprising a belt, more preferably a toothed belt.

[0021] In some embodiments, the front wheels are of a larger diameter than the rear wheels.

[0022] In certain embodiments, an outside diameter DF of the front deformable rolling elements is such that DF > 2H, preferably 3H > DF > 2.05H, where H is the height of the stair steps that the rolling equipment must traverse. In one example embodiment, DF > 34 cm, preferably 51 cm > DF > 35 cm. These values ​​of DF are suitable for the case where H = 17 cm. This value of H is a value usually imposed by construction standards. In certain embodiments, an outside diameter DR of the rear deformable rolling elements is such that DR > 2H, preferably 3H > DR > 2.05H.

[0023] In certain embodiments, each of the deformable front rolling elements and / or each of the deformable rear rolling elements includes a pneumatic tire.

[0024] In certain embodiments, the deformable front rolling elements and / or the deformable rear rolling elements are made of a material having a Shore A hardness between 50 inclusive and 70 inclusive.

[0025] In certain embodiments, a wheelbase E between the front and rear rims is such that 3.02 H < E < 3.71 H and / or 1.56 P < E < 1.91 P, where P is the depth of the stair treads that the rolling vehicle must traverse. In one example embodiment, 51.5 cm < E < 63.0 cm. These values ​​of E are suitable for the case where H = 17 cm and P = 33 cm. These values ​​of H and P are values ​​usually imposed by construction standards.

[0026] The invention further proposes a method for enabling a person to ascend a staircase using a rolling device according to any one of the embodiments described above, the staircase comprising a plurality of steps, each having a height H, and an outside diameter DF of the deformable front rolling elements of the rolling device being such that DF > 2H, preferably 3H > DF > 2.05H, the method comprising the following steps: - have the person sit down in the seat; and - supply at least one electric motor with electricity from the on-board power source, so that the front rims of the front wheels and the rear rims of the rear wheels are driven in rotation and the rolling machine goes up the stairs.

[0027] In certain embodiments where the plurality of steps each has a depth P, a wheelbase E between the front rims and the rear rims is such that 3.02 H < E < 3.71 H and / or 1.56 P < E < 1.91 P. Brief description of the figures

[0028] The following description, with reference to the accompanying drawings, given by way of non-limiting examples, will clearly explain what the invention consists of and how it can be implemented. In the accompanying figures:

[0029] [Fig. 1] The [Fig. 1] is a perspective view of a rolling vehicle for transporting persons according to an embodiment of the invention;

[0030] [Fig.1A] The [Fig.1A] is a diagram showing a variant embodiment of the chassis of the machine;

[0031] [Fig.2] Fig.2 is a top view of the chassis of the machine;

[0032] [Fig.3] The [Fig.3] is a partial perspective view of the front of the machine;

[0033] [Fig.4] The [Fig.4] is another partial perspective view of the front of the machine;

[0034] [Fig.4A] The [Fig.4A] is a diagram showing a casing element of the chassis of the machine;

[0035] [Fig.5] The [Fig.5] is a partial perspective view of the rear of the machine;

[0036] [Fig.6A] The [Fig.6A] is a diagram intended to explain the dimensioning of the front wheels of the machine;

[0037] [Fig.6B] The [Fig.6B] is a diagram intended to explain the dimensioning of the wheelbase of the machine;

[0038] [Fig.7] The [Fig.7] is another partial perspective view of the machine, showing a control box for controlling a control unit and the electric motors of the machine;

[0039] [Fig.8] The [Fig.8] is a simplified representation of the propulsion system of a rolling vehicle for transporting persons according to another embodiment of the invention;

[0040] [Fig.9] The [Fig.9] is a simplified representation of a rolling vehicle for transporting persons according to yet another embodiment of the invention. Description of method(s) of implementation

[0041] In the figures, and unless otherwise specified, identical elements shall bear the same reference symbols.

[0042] Figure 1 shows in perspective a wheeled vehicle for transporting persons according to a first embodiment of the invention, in the form of a child's stroller 1 (hereinafter "the stroller 1"). The stroller 1 comprises a chassis 10 which supports a seat 90 for a child.

[0043] With reference to figures 1 to 3, the chassis 10 has two front uprights 18 and two rear uprights 14. The front uprights 18 are parallel and each carries at their lower end a front wheel 2. Similarly, the rear uprights 14 are parallel and each carries at their lower end a rear wheel 3. The front wheels 2 and the rear wheels 3 allow the chassis 10 to roll on the ground.

[0044] The upper ends of the rear uprights 14 are connected by a handle 15. The handle 15 allows a person to guide and push the stroller 1, and to hold the stroller 1 when it is going up or down stairs. Optionally, a crossbar 14A extends between the rear uprights 14 to allow for the attachment of luggage or a container such as a shopping bag 95. It should be noted that the shopping bag 95 has been omitted from the drawing in [Fig. 2] and [Fig. 7] in order to better visualize other elements of the stroller 1.

[0045] The seat 90 is fixed to the front uprights 18. In the example shown, the seat 90 is fixed to the front uprights 18 and includes a backrest 91 extending between the front uprights 18 and a leg rest 92 inclined relative to the backrest 91. Alternatively, the seat 90 can be made in a large number of other ways as long as it is attached to the front uprights 18 and allows a child to be seated in the stroller 1. It is specified that the seat 90 has been omitted from the drawing on [Fig.2] and [Fig.3] in order to better visualize other elements of the stroller 1. It should also be noted that the stroller 1 may have several separate seats 90 which each allow a child to be seated in the stroller 1, or even a single seat 90 which allows several children to be seated in the stroller 1.

[0046] The chassis 10 further comprises two lower elements 11. The lower elements 11 are parallel and arranged between the lower ends of the front uprights 18 and the lower ends of the rear uprights 14. With reference to figures 2, 3 and 4, the front ends of the lower elements 11 are fixed to the lower ends of the front uprights 18, here by means of nuts screwed onto a threaded rod 12 which has a central portion 12A extending between the lower elements 11 and two lateral portions 12B each extending between a lower element 11 and a front upright 18.With reference to Figures 2 and 5, the rear ends of the lower elements 11 are fixed to the lower ends of the rear uprights 14, here by means of nuts screwed onto a threaded rod 13 which has a central portion 13A extending between the lower elements 11 and two lateral portions 13B each extending between a lower element 11 and a rear upright 14. A reinforcement 14R (see [Fig. 5]) can be fixed to a rear upright 14 and an adjacent lateral portion 13B.

[0047] The stroller 1 includes a propulsion system for propelling the chassis 10. This propulsion system includes the front wheels 2 and the rear wheels 3, electric motors 22 and an on-board power source.

[0048] In the example shown, the on-board power source comprises or consists of a battery 88, advantageously a lithium-ion battery. The battery 88 is preferably attached to and below the lower elements 11, as shown in Figures 1 to 3. This lowers the center of gravity of the stroller 1, preventing it from tipping over when going down stairs or an incline. Alternatively, the on-board power source can be implemented in other ways, for example, as a capacitor bank. In this case as well, it is preferable for the on-board power source to be attached to and below the lower elements 11.

[0049] The battery 88 is connected to the electric motors 22 via a control unit 89. This control unit 89 supplies the electrical power delivered by the battery 88 to the electric motors 22, according to a user command. The control unit 89 is preferably attached to and below the lower elements 11 as shown in Figures 1 to 3. Preferably, the control unit 89 is attached to the battery 88.

[0050] In the example shown in Figures 2, 3, and 4, the two lower elements 11 each consist of a rigid element such as a bar or rod. Alternatively, as schematically shown in [Fig. 1A], each of the two lower elements 11 comprises two rigid elements 11-1, 11-2 such as a bar or rod. The battery 88 and the control unit 89 are preferably attached to and below one of the rigid elements 11-1. The rigid elements 11-1, 11-2 are coupled to each other via a slidingly mounted rigid element 1IX and at least two elastic elements 11R such as springs. In this way, the rigid elements 11-1, 11-2 are likely to move relative to each other within a range of movement permitted by the rigid element 1IX, the elastic elements 1 IR tending to return the rigid elements 11-1, 11-2 to a position in which they are aligned.This allows the stroller 1 to comfortably overcome small bumps without requiring a suspension spring on the front wheels 2 and / or the rear wheels 3.

[0051] With reference to [Fig. 3] and [Fig. 4], an electric motor 22 is associated with each front wheel 2. For this purpose, the electric motor 22 is fixed in the vicinity of the front wheel 2, here by being attached to a plate 42 which is fixed to the front upright 18. The electric motor 22 is arranged to drive a front pulley 52. ​​Advantageously, as can be more clearly seen in [Fig. 4], the electric motor 22 drives the front pulley 52 via an auxiliary belt 62. It will be understood by referring to [Fig. 3] and [Fig. 4] that in this way, the electric motor 22 is offset relative to the axis of rotation of the front pulley 52. ​​This greatly facilitates the positioning and fixing of the electric motor 22, and allows the front pulley 52 to be fixed to the threaded rod 12 or at least in line with the threaded rod 12.Preferably, the auxiliary belt 62 is a toothed belt, which ensures good transmission of the torque produced by the electric motor 22 to the front pulley 52. ​​For this purpose, the toothed auxiliary belt 62 can be replaced by a chain, for example, a bicycle or motorcycle chain. However, the auxiliary belt 62 can also be a smooth belt without departing from the scope of the invention.

[0052] With reference now to [Fig. 3], the front wheel 2 comprises a rim 2J and a tire 2P arranged around the rim 2J, and the front pulley 52 is coupled to the rim 2J. Advantageously, the rim 2J is a bicycle wheel rim, that is to say, the rim 2J is annular and connected via spokes 2R to a hub 2M. In this case, the front pulley 52 is coupled to the rim 2J via the hub 2M. In this way, the rim 2J is lightened, which lightens the stroller 1 and thus facilitates its transport, particularly when folded. However, the rim 2J can have other geometries, and can in particular be solid, without departing from the scope of the invention.

[0053] When the electric motors 22 are operating, the front pulleys 52 are driven in rotation, which results in a rotational drive of the rims 2J and thus turns the front wheels 2. But in addition, the front pulleys 52 are part of a transmission assembly 21 which further includes two drive belts 23 and two rear pulleys 53. As can be seen in Figures 1 to 5, each of the drive belts 23 is wound around a front pulley 52 and a rear pulley 53.

[0054] In the example shown, the drive belts 23 are toothed belts. This ensures good transmission of the torque produced by the electric motors 22 to the rear pulleys 53. For this purpose, the toothed drive belts 23 can be replaced by chains, for example, bicycle or motorcycle chains. However, the drive belts 23 can also be smooth belts without departing from the scope of the invention.

[0055] The frame 10 preferably includes at least one guide 25 (see [Fig.1], [Fig.3] and [Fig.4]) per drive belt 23 to guide this drive belt 23. As can be seen more clearly in Figures 3 and 4, each guide 25 may include two guide rollers 25A on either side of the drive belt 23.

[0056] Figures 3, 4, and 5 further show that, advantageously, two guides 25, each associated with a drive belt 23, are carried by a single rod 19. The rod 19 is constantly subjected to bending, so that the guides 25 carried by the rod 19 keep the drive belts 23 taut. On the other hand, when the pusher 1 moves, the rod 19 is subjected to bending and / or torsion, which allows the drive belts 23 to remain taut. To hold the rod 19 in place, the frame 10 has two stiffeners 17 (see [Fig.3], [Fig.4] and [Fig.5]) connecting the rod 19 to the threaded rod 13. Advantageously, each stiffener 17 has two bends 17U (see [Fig.3]) and 17V (see [Fig.5]) in opposite directions, so that the stiffener 17 has an overall "S" shaped profile.

[0057] The chassis 10 preferably comprises two housing elements 80, one of which is shown schematically in [Fig. 4A]. The housing element 80 surrounds at least partially one of the two drive belts 23. For this purpose, at least a portion of the housing element 80 has a width 80W greater than the width of the drive belt 23. This improves the safety of the stroller 1, because a child sitting in the stroller 1 or walking beside it cannot easily touch the drive belts 23. The reliability of the stroller 1 is also improved because the drive belts 23 are protected against soiling and against impacts with nearby objects.

[0058] With reference to [Fig. 5], the rear wheels 3 are constructed in a manner analogous to the front wheels 2, that is to say, a rear wheel 3 comprises a rim 3J and a tire 3P arranged around the rim 3J. Also in a manner analogous to the wheels Before 2, the 3J rim is a bicycle wheel type rim, meaning that the 3J rim is annular and connected via spokes 3R to a hub 3M. In this case, the front pulley 53 is coupled to the 3J rim via the hub 3M. In this way, the 3J rim is lightened, which lightens the stroller 1 and therefore facilitates its transport, especially when folded. However, the 3J rim can have other geometries, and in particular be solid, without departing from the scope of the invention.

[0059] As can be seen in [Fig.5], and in a manner analogous to the front pulleys 52, the rear pulleys 53 can be fixed on the threaded rod 13 or at least in the extension of the threaded rod 13.

[0060] Thanks to the transmission assembly 21 just described, the rotational drive of the rims 2J of the front wheels 2 by the electric motors 22 drives the rims 3J of the rear wheels 3, via the drive belts 23 and the rear pulleys 53. Thus, and also thanks to the fact that the tires 2P and 3P are deformable, the stroller 1 can climb a staircase without any action from the person pushing the stroller 1, provided that the electric motors 22 supply sufficient torque to the front wheels 2. Tests carried out by the inventor revealed that if the outside diameter DF (see [Fig. 6A]) of the tires 2P is approximately 40 cm (i.e., approximately 16 inches, where 1 inch = 25.4 mm), two electric motors 22 of 1.0 kW each are sufficient for a stroller 1 with a total unladen weight of 5.5 kg to climb a staircase stairs.Of course, the power of the 22 electric motors can be different (and in particular higher), especially depending on the total weight expected when loaded with the stroller 1. For example, the 22 electric motors can each be 1.5 kW, 2 kW or 3 kW motors.

[0061] Preferably, the transmission assembly 21 does not include a clutch between the electric motors 22 and the rims 2J. This considerably simplifies and lightens the transmission assembly 21. Such clutches are not necessary in any case because the tires 2P and 3P tend to absorb any shock due to an irregularity in the path of the stroller 1, whether the electric motors 22 are powered or not.

[0062] It should be noted that the front pulleys 52 can be mounted so as to permanently oppose the rotation of the front wheels 2. For example, the front pulleys 52 can be fixed by nuts in such a way that the front wheels 2 rotate against the tightening force of these nuts. Thus, the front wheels 2 are permanently braked, which provides an additional degree of safety to the stroller 1. Similarly, the rear pulleys 53 can be mounted so as to permanently oppose the rotation of the rear wheels 3.

[0063] In [Fig. 6A], to explain the dimensioning of the front wheels 2, one of the front wheels 2 is schematically represented engaged in a staircase 2000, this staircase 2000 comprising stair steps 2002, 2012, ... which have Each has a height H. Generally, the value of H is dictated by local building codes. Purely as an example, H = 17 cm is a value commonly required by building codes, particularly in France.

[0064] By observing [Fig. 6A], it will be understood that it is particularly preferable for the outside diameter DF of the tires 2P to be strictly greater than 2H, in other words, for DF > 2H. For example, DF > 2.05H. Indeed, in this case, the horizontal diameter of the front wheel 2 is greater than the step 2012 that the front wheel 2 is about to cross. Thus, the front wheel 2 can cross the step 2012 without significant difficulty, thanks to the torque supplied by the electric motor 22 and with a local deformation of the tire 2P in the region indicated by the marker Q on [Fig. 6A]. On the other hand, the drive of the rear wheels 3 by the transmission assembly 21 (not shown in [Fig.6A]) also provides torque to the rear wheels 3, which further helps the stroller 1 to climb the stair steps 2002, 2012, ....Thus, and as already mentioned above, once the electric motors 22 are powered, the stroller 1 can climb a staircase 2000, without any action from the person pushing the stroller 1 (except to activate the propulsion system).

[0065] In an example embodiment, DF > 34 cm, for example DF > 35 cm. These values ​​of DF are suitable for the case where H = 17 cm.

[0066] However, it is preferable that the front wheels 2 not be too large in diameter, both to facilitate the transport of the stroller 1 and to allow the stroller 1 to climb several steps 2002, 2012, ... without being blocked due to an excessive diameter of the front wheels 2. Thus, in a preferred example, 3H > DF > 2.05H. In the case where H = 17 cm, we have 51 cm > DF > 35 cm.

[0067] Of course, the outside diameter of the 3P tires also preferably satisfies the above inequalities.

[0068] In [Fig. 6B], to explain the choice of the wheelbase E between the front wheels 2 and the rear wheels 3, one of the front wheels 2 and one of the rear wheels 3 engaged in the stair 2000 are schematically represented. The wheelbase E is defined as the shortest distance between the axis of rotation of the rims 2J and the axis of rotation of the rims 3J. This shortest distance is considered orthogonal to the axis of rotation of the rims 2J and the axis of rotation of the rims 3J, in other words, parallel to a front-to-rear axis of the stroller 1. In addition to the height H mentioned above, the stair treads 2002, 2012, 2022, 2032, 2042, 2052, ... each have a depth P. In general, the value of P is imposed by local building codes. Purely as an example, P = 33 cm is a value usually imposed by construction standards, particularly in France.

[0069] By observing [Fig. 6B], it will be understood that it is particularly preferable for the wheelbase E to be chosen such that when the rear wheel 3 (respectively the front wheel 2) is bearing against the step it is about to cross (here step 2012), the front wheel 2 (respectively the rear wheel 3) is not bearing against the step it is about to cross (here step 2032). Otherwise, the electric motors 22 would be forced to provide extremely high torque in order for the front wheels 2 and the rear wheels 3 to be able to cross a stair step simultaneously (here steps 2012 and 2032). For this, preferably, the serif E satisfies at least one of the inequalities 3.02 H < E < 3.71 H and 1.56 P < E < 1.91 P, and more preferably the serif E satisfies both of these inequalities simultaneously.

[0070] In one embodiment, 51.5 cm < E < 63.0 cm. These values ​​of E are suitable for the case where H = 17 cm and P = 33 cm. Indeed, we have: 3.02 H = 51.3 cm; 3.71 H = 63.1 cm; 1.56 P = 51.5 cm; and 1.91 P = 63.0 cm. These values ​​advantageously correspond to the usual lengths of drive belts 23.

[0071] In view of the foregoing, it will be understood that the invention relates not only to a person transport device (such as the stroller 1), but also to a method for transporting a person (such as a child) up a staircase 2000 using the person transport device, the staircase 2000 comprising a plurality of steps 2002, 2012, ... each having a height H, and the outside diameter DF of the tires 2P being such that DF > 2H, preferably 3H > DF > 2.05H, the method comprising the following steps: - have the person sit in seat 90; and - supply the electric motors 22 with electricity from the battery 88, so that the front wheels 2 and the rear wheels 3 are driven in rotation and the person transport vehicle climbs the stairs 2000. In such a process, the wheelbase E between rims 2J and rims 3J is such that 3.02 H < E < 3.71 H and / or 1.56 P < E < 1.91 P.

[0072] The 2P tires can be replaced without any problem by any other type of deformable rolling element, for example, a solid elastomer rolling element or a hollow elastomer rolling element filled with a liquid, balls, etc. However, it is important that the 2P tires or the rolling elements that replace them be deformable so that the front wheels 2 can cross a step 2012 under the effect of the torque supplied by the electric motors 22 without significant difficulty. For this purpose, it is preferable that the material of the 2P tires or the rolling elements that replace them have a Shore A hardness between 50 and 70 inclusive.

[0073] As for 3P tires, they can also be replaced without inconvenience by any other type of deformable rolling element, such as 2P tires. However, it is important that the 3P tires or their replacement rolling elements be deformable so that, once the front wheels 2 have already crossed a step 2012, the rear wheels 3 can in turn cross a step 2002 without significant difficulty. Conversely, if the rear wheels 3 were rigid, they would slip and struggle to cross a step 2002. For this reason, it is preferable that the material of the 3P tires or their replacement rolling elements have a Shore A hardness between 50 and 70 inclusive.

[0074] The 2P and 3P tires, or the deformable rolling elements that replace them, are preferably made of the same material.

[0075] Returning to [Fig. 1], we see that the front wheels 2 are preferably of a larger diameter than the rear wheels 3. In this way, and since the torque delivered by the electric motors 22 is transmitted first to the front wheels 2, the front wheels 2 receive a significant torque which is sufficient to climb a step 2002, 2012, ... while the rear wheels 3 receive a lesser torque which still helps the stroller 1 to climb the staircase 2000. Nevertheless, the front wheels 2 and the rear wheels 3 can be of the same diameter without departing from the scope of the invention.

[0076] As mentioned above, the control unit 89 can supply the electrical power delivered by the battery 88 to the electric motors 22 according to a user command. This user command can be given in various ways by the person pushing the stroller 1. For example, the person can simply press a button that controls the starting and stopping of the electric motors 22 on the control unit 89, this button being integrated into the chassis 10, for example on the handle 15. Alternatively, this user command can also be given by the person pushing the stroller 1 by means of a control box 96.

[0077] An example of an embodiment of the control box 96 is shown in [Fig. 7]. In this example, the control box 96 is separate from the chassis 10 and is wireless, i.e., the control box 96 is connected to the control unit 89 via a suitable wireless connection, for example, via a Bluetooth connection (registered trademark). As shown, the control box 96 is preferably small enough to be held by the person pushing the stroller 1 in one hand MH. The control box 96 advantageously includes a wrist strap 98 to prevent the control box 96 from being lost or dropped.

[0078] In the example shown, the control box 96 has a button or selector 97. This button or selector 97 allows the person pushing the stroller 1 to control the start and stop of the electric motors 22. The control box 96 may also include an indicator 99, here in the form of a screen, to display to the person the charge level of the battery 88.

[0079] Alternatively, the control box 96 can be permanently fixed on the chassis 10 and / or be wired, without departing from the scope of the invention.

[0080] Figure 8 is a simplified representation of the propulsion system of a vehicle Person transport 301 according to another embodiment of the invention. In this figure, elements similar or identical to those described with reference to Figures 1 to 7 bear the same reference numbers increased by 300 and are not described again except where necessary.

[0081] The person transport vehicle 301 differs from the person transport vehicle 1 in its propulsion system and more particularly in its transmission assembly 321.

[0082] As shown, instead of an electric motor for each of the front wheels 302, the propulsion system comprises a single electric motor 322 configured to drive the rotation of the rims 302J of the front wheels 302. In addition, the transmission assembly 321 includes a front differential 372 and a rear differential 373. The front differential 372 is driven by the electric motor 322 and drives the rotation of the rims 302J of the front wheels 302. The rear differential 373 is driven by the front differential 372 and drives the rotation of the rear wheels 303, in this case driving their rims 303J.

[0083] In the example shown, the rear differential 373 is driven by the front differential 372 via an intermediate differential 374. This intermediate differential 374 is connected to the front differential 372 by a first driveshaft 375 and to the rear differential 373 by a second driveshaft 376. The first driveshaft 375 and / or the second driveshaft 376 may be cardan shafts, for example. Alternatively, the intermediate differential 374 may be omitted, in which case the rear differential 373 is connected directly to the front differential 372 by one or more driveshafts, such as cardan shafts.

[0084] The person transport vehicle 301 is otherwise identical to the person transport vehicle 1 and is therefore not described in more detail for the sake of brevity.

[0085] It should be noted that the chassis 10 of the person transport vehicle 1, 301 can be constructed in various ways, as long as the chassis 10 supports a seat 90 and as long as the person transport vehicle 1, 301 includes the propulsion system described. The specific construction of the chassis 10 shown in Figures 1 to 5 and 7 is therefore in no way limiting.

[0086] It should also be noted that even though the person transport device 1,301 has been described as a child's stroller, it could also be a wheelchair, for for children or adults. The construction of the frame 10 and possibly the seat 90 is then adapted accordingly. The control unit 96 can then be placed on the frame 10 or on the seat 90 so that it can be operated by the child or adult seated in the seat 90.

[0087] Figure 9 is a simplified representation of a person transport device 401 according to another embodiment of the invention, in the form of a wheelchair, for a child or for an adult. In this figure, elements similar or identical to those described with reference to Figures 1 to 7 bear the same reference numbers plus 400 and are not described again except where necessary.

[0088] In the person transport vehicle 401, the rear wheels 403 have a larger diameter than the front wheels 402, as is common for wheelchairs. Furthermore, unlike the person transport vehicle 1 or 301, an electric motor 422 drives the rim 403J of a rear wheel 403, rather than the rim 402J of a front wheel 402. More precisely, an electric motor 422 drives a rear pulley 453. The rotation of the rims 403J of the rear wheels 403 by the electric motors 422 drives the rims 2J of the front wheels 402, via the drive belts 23 and the front pulleys 452.

[0089] Fig. 9 also shows that the battery 488 can be placed behind the backrest 491 of the seat 490, rather than under the seat 490.

Claims

Demands

1. A rolling device for transporting persons, the rolling device (1, 301, 401) being a child's stroller or a wheelchair and the rolling device comprising a chassis (10) which supports a seat (90, 490) for a person and a propulsion system for propelling the chassis (10), the propulsion system comprising: - wheels enabling the chassis (10) to roll on the ground, the wheels comprising two front wheels (2, 302, 402) and two rear wheels (3, 303, 403); - at least one electric motor (22, 322, 422); and - an on-board source of electricity (88, 488) for supplying said at least one electric motor (22, 322, 422) with electricity, wherein each of the two front wheels (2, 302, 402) comprises a rigid front rim (2J, 302J, 402J) and a deformable front rolling element (2P, 302P, 402P) arranged around the front rim (2J, 302J, 402J), wherein each of the two rear wheels (3, 303, 403) comprises a rigid rear rim (3J, 303J,403J) and a deformable rear bearing element (3P, 303P, 403P) arranged around the rear rim (3J, 303J, 403J), wherein said at least one electric motor (22, 322, 422) is configured to effect a rotational drive of one of the front rims (2J, 302J, 402J) and the rear rims (3J, 303J, 403J), and the propulsion system further comprises a transmission assembly (21, 321, 421) configured such that said rotational drive drives the other of the front rims (2J, 302J, 402J) and the rear rims (3J, 303J, 403J).

2. Rolling machine (1, 301) according to claim 1, wherein said at least one electric motor (22, 322) is configured to perform a rotational drive of the front rims (2J, 302J) and the transmission assembly (21, 321) is configured so that said rotational drive drives the rear rims (3J, 303J).

3. Rolling vehicle (301) according to claim 2, wherein the propulsion system comprises a single electric motor (322) configured to provide a rotational drive to the front rims (302J) of the two front wheels (302), and wherein the transmission assembly (321) comprises a front differential (372) and a rear differential (373), the front differential (372) being driven by the electric motor (322) and driving the front rims (302J) of the two front wheels (302) in rotation, the rear differential (373) being driven by the front differential (372) and driving the rear rims (303J) of the two rear wheels (303).

4. Rolling machine (1) according to claim 2, wherein the propulsion system comprises two electric motors (22), each of the two electric motors (22) being configured to effect a rotational drive of the front rim (2J) of one of the front wheels (2), and the transmission assembly (21) being configured such that the rotational drive of the front rim (2J) of one of the front wheels (2) drives the rear rim (3J) of one of the rear wheels (3).

5. Rolling machine (1) according to claim 4, wherein the transmission assembly (21) does not include a clutch between the electric motors (22) and the front rims (2J).

6. Rolling machine (1) according to any one of claims 4 to 5, wherein the transmission assembly (21) comprises two front pulleys (52) each coupled to the front rim (2J) of one of the front wheels (2), two rear pulleys (53) each coupled to the rear rim (3J) of one of the rear wheels (3), and two continuous drive elements (23) each wound around a front pulley (52) and a rear pulley (53), the two continuous drive elements (23) each comprising a chain, a toothed belt or a smooth belt, and each of the two electric motors (22) being arranged to drive one of the front pulleys (52).

7. Rolling machine (1) according to claim 6, in which each of the two electric motors (22) drives one of the front pulleys (52) via an auxiliary continuous drive element (62), the auxiliary continuous drive element (62) preferably comprising a belt, more preferably a toothed belt.

8. Rolling machine (1) according to any one of claims 1 to 7, wherein the front wheels (2) are of a larger diameter than the rear wheels (3).

9. Rolling machine (1) according to any one of claims 1 to 8, wherein an outside diameter DF of the deformable front rolling elements (2P) is such that DF > 34 cm, preferably 51 cm > DF > 35 cm.

10. A method for making a person ascend a staircase (2000) by means of a rolling device (1, 301) according to any one of claims 1 to 9, the staircase comprising a plurality of steps (2002, 2012) each having a height H, and an outside diameter DF of the deformable front rolling elements (2P) of the rolling device (1, 301) being such that DF > 2H, preferably 3H > DF > 2.05H, the method comprising the following steps: - making the person sit in the seat (90); and - supply at least one electric motor (22, 322) with electricity from the on-board power source (88), so that the front rims (2J, 302J) of the front wheels (2, 302) and the rear rims (3J, 303J) of the rear wheels (3, 303) are driven in rotation and the rolling machine (1) goes up the stairs (2000).

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