EP4125763A1

EP4125763A1 - Removable electric propulsion system for a rolling object with a device for releasing the handlebar

Info

Publication number: EP4125763A1
Application number: EP21711554.2A
Authority: EP
Inventors: Stephane Venturi; Bertrand Lecointe
Original assignee: IFP Energies Nouvelles IFPEN
Current assignee: IFP Energies Nouvelles IFPEN
Priority date: 2020-03-25
Filing date: 2021-03-12
Publication date: 2023-02-08

Abstract

The present invention relates to a removable electric propulsion system (1) intended to be coupled to a rolling object. The propulsion system (1) comprises a frame (2) provided with at least one wheel (3) driven by an electric machine and with at least one non-driven wheel (4), a handlebar (20) and means (5) for coupling the propulsion system to the rolling object, the coupling means (5) comprising means for gripping and lifting at least one wheel of the rolling object. The handlebar (20) comprises a link to the frame (2) and/or to the driven wheel (3). Furthermore, the link comprises a means (12) for locking/unlocking the handlebar relative to the frame (2) and/or relative to a driven wheel (3) from a locking position, whereby the handlebar (20) is fixed to the frame (2) and/or to the driven wheel (3), this locking position of the handlebar (20) allowing the electric propulsion system (1) to move by virtue of the handlebar (20) to an unlocking position allowing at least a free movement of the handlebar (20) relative to the frame (2) and/or to the driven wheel (3).

Description

REMOVABLE ELECTRIC PROPULSION SYSTEM FOR A ROLLING OBJECT WITH A HANDLEBAR REMOVAL DEVICE

Technical area

The invention relates to the field of transporting rolling objects, in particular rolling beds, for example hospital beds.

The movement of heavy rolling loads by a user can cause difficulties for the user, particularly if this action is repeated, such as musculoskeletal disorders.

Prior art

In order to make the movement of heavy rolling loads easier and more ergonomic, it has been envisaged to equip these heavy loads with electric machines. For example, a first idea was to equip each hospital bed with an electric wheel drive system. Such a solution is expensive because it requires replacing or modifying all the beds, which hospitals cannot afford. In addition, the drive system and its battery increase the weight of the bed. Consequently, when the battery is discharged, the efforts required to move the bed are greater.

Likewise, in the field of logistics or commerce, it has been envisaged to make all the trolleys electric. Here too, such a solution is expensive.

An alternative is to provide a removable propulsion system for rolling objects. Several technical solutions have been considered.

For example, patent application WO 01/85086 describes a motorized propulsion system for a bed. The propulsion system is configured to hitch to one or more points of the bed. Due to the coupling means provided for this propulsion system, this system cannot be universal and adapted to different rolling objects. Indeed, it cannot be hitched to a rolling object not provided with a hitching part. In addition, for this propulsion system, all the wheels of the rolling object remain in contact with the ground. As a result, the orientation of the hitch (propulsion system and bed) is more complicated, the frictional forces are high, and the motorized wheel requires more power. In In addition, the system includes a handlebar positioned behind the bed, which represents a significant longitudinal bulk.

Patent application WO 2012/171079 describes a second system for propelling a hospital bed. The propulsion system is configured to lift two wheels from the bed. However, the wheel gripping mechanism is complex and bulky: the lateral dimension (direction parallel to the axis of the motorized wheels) is large (greater than the width of the wheels of the bed) and may exceed the lateral dimensions of the bed, which can be inconvenient when moving the bed, especially in a small space such as a hallway or a hospital elevator. In addition, the system includes a handlebar positioned behind the bed, which represents a significant longitudinal bulk.

Patent application WO 2013/156030 describes a third system for propelling a hospital bed. The propulsion system is configured to lift two wheels from the bed. However, the system has lateral (direction parallel to the axis of the motorized wheels) and longitudinal (direction perpendicular to the axis of the wheels) dimensions which are important: the rear platform exceeds the bed and the distance between the non-motorized wheels can exceed the dimensions of the bed, which can be inconvenient for moving the bed, especially in a small space, such as a hallway or a hospital elevator. In addition, the system includes a handlebar positioned behind the bed, which represents a significant longitudinal bulk.

The present invention proposes to solve the problems of the prior art, in particular the problems of space requirement and more particularly the problems of longitudinal space, in the direction of movement of the rolling object coupled to the system. The system can also adapt to different rolling objects and provide high maneuverability, especially in tight spaces.

To do so, the present invention relates to a removable electric propulsion system intended to be hitched to a rolling object. The propulsion system comprises a frame provided with at least one wheel driven by an electric machine, and at least one non-driven wheel, a handlebar and means for coupling the propulsion system to the rolling object, the means coupling comprising means for gripping and lifting at least one wheel of the rolling object. The handlebar comprises a connection to the frame and / or to the driven wheel. In addition, the link comprises a means for locking / unlocking the handlebars with respect to the chassis and / or a driven wheel from at least one (locking) position where the handlebar is fixed to the chassis and / or to the driven wheel, this (or these) locking position (s) of the handlebars allowing the electric propulsion system to be moved using the handlebars to a (unlocking) position allowing at least one free movement of the handlebars relative to the chassis and / or the driven wheel, so as to retract the handlebars (or "erase" the handlebars, that is to say to position it in a location limiting the size, in particular reducing the longitudinal size, without causing the displacement and / or the orientation of the propulsion system electric).

Summary of the invention

The invention relates to a removable electric propulsion system for a rolling object, said propulsion system comprising a frame provided with at least one wheel driven by an electric machine, and at least one non-driven wheel, a handlebar and means. coupling said propulsion system to said rolling object. Said coupling means comprise means for gripping and lifting at least one wheel of said rolling object and said handlebar comprises a connection to said frame and / or to said driven wheel. In addition, said link comprises means for locking / unlocking said handlebar with respect to said chassis and / or to a driven wheel from at least one locking position where the handlebar is fixed to said chassis and / or to said driven wheel, this at least a locking position of said handlebar making it possible to move the electric propulsion system by means of said handlebar, towards an unlocking position allowing at least one free movement of said handlebar relative to said frame or to said driven wheel.

Advantageously, said locking / unlocking means comprises an axis, preferably, said axis being fixed to the frame or to said driven wheel.

According to a variant of the invention, said locking / unlocking means comprises two locking positions, a first locking position connecting said handlebar to said frame and a second locking position connecting said handlebar to said driven wheel.

Preferably, said coupling means comprise means for orienting at least one wheel of said rolling object in a direction forming a non-zero angle with the longitudinal direction of said frame of said propulsion system, preferably said coupling means comprises means for orienting at least one wheel of said rolling object in a direction substantially perpendicular to the longitudinal direction of said frame of said propulsion system. Advantageously, said electric propulsion system comprises control means for controlling said locking / unlocking means.

According to one embodiment, said handlebar comprises an arm, preferably the arm being articulated.

Preferably, the arm comprises a connecting part and a connecting rod, said connecting part comprising said locking / unlocking means, said connecting rod being articulated with respect to said connecting part about a first horizontal axis.

Advantageously, said handlebar comprises an operating part and a locking / unlocking means, said locking / unlocking means connecting said operating part and said connecting rod.

According to an advantageous implementation, said control means controls said locking / unlocking means and said locking / unlocking means, preferably simultaneously.

According to a variant, said locking / unlocking means comprises at least two configurations, a first configuration in which said operating part is in a pivot connection about a second axis with respect to said connecting rod, and a second configuration in which said control part. maneuver is rigidly fixed to said connecting rod.

According to one embodiment of the invention, said handlebar comprises a control panel.

In addition, the invention relates to a method for retracting said handlebar from a system according to one of the characteristics described above, in which at least the following steps are carried out:

- Said locking / unlocking means is unlocked, said handlebar then being able to move freely relative to said frame and / or to said driven wheel;

- said handlebars are moved.

Preferably, the steps are carried out after having hitched said rolling object to said removable electric propulsion system. According to one implementation of the method, said locking / unlocking means is unlocked, preferably simultaneously with the unlocking of said locking / unlocking means.

Advantageously, after having moved said handlebars, said operating part is pivoted.

The invention also relates to a method for guiding the removable electric propulsion system by said handlebar in which at least the following steps are carried out:

- Said handlebar is connected to said frame and / or to said driven wheel, preferably automatically or semi-automatically, by said locking / unlocking means, said handlebar being rigidly fixed to said frame and / or to said driven wheel;

- Acting on said handlebars to move and / or orient the removable electric propulsion system.

Preferably, said operating part is blocked to said connecting rod by said locking / unlocking means, preferably simultaneously with the locking of said handlebar to said frame and / or to said wheel driven by said locking / unlocking means.

List of Figures

Other characteristics and advantages of the system and of the methods according to the invention will emerge on reading the following description of non-limiting examples of embodiments, with reference to the appended figures and described below.

Figure 1 is a top view of a propulsion system according to one embodiment of the invention.

Figure 2 is a side view of a propulsion system according to a first variant embodiment of the invention.

Figure 3 is a side view of a propulsion system according to a second embodiment of the invention.

Figure 4 is a top view of a propulsion system according to one embodiment hitched to a rolling object.

FIG. 5 is a side view showing a first embodiment of the connection of the handlebar to the frame of the system according to the invention. FIG. 6 is a side view showing an embodiment of the connection of the handlebars to the driven wheel of the system according to the invention.

Figure 7 shows a variant of the handlebar of the system of the invention in position 20 "of Figure 1. Figure 8 shows a variant of the handlebar of the system of the invention in position 20 "of Figure 1.

Figure 9 shows a variant of the handlebar of the system of the invention in the 20 "" position of Figure 1.

Figure 10 shows an advantageous variant of the locking / unlocking means of the system of the invention in the unlocked position.

Figure 11 shows the advantageous variant of the locking / unlocking means of the system of the invention of Figure 10 in a first locking position, linked to the frame.

Figure 12 shows the advantageous variant of the locking / unlocking means of the system of the invention of Figure 10 in a second locking position, linked to the driven wheel.

Figure 13 is a top view of a propulsion system according to a first embodiment coupled to a rolling object with most of the propulsion system positioned under the rolling object. Figure 14 is a top view of a propulsion system according to a second embodiment hitched to a rolling object with most of the propulsion system positioned under the rolling object.

FIG. 15 is a top view of a propulsion system according to the second embodiment coupled to a rolling object with the major part of the propulsion system positioned under the rolling object and the operating part oriented along the longitudinal axis .

Description of the embodiments

The present invention relates to an electric propulsion system for a rolling object. We call an electric propulsion system a removable system allowing to assist the movement of the rolling object, in order to limit the forces required for the movement of the rolling object. This electric propulsion system comprises at least one electric machine for its drive. A rolling object is an object that has at least two wheels in order to move it.

The rolling object can be of any shape, including a rolling bed, such as in particular those used in hospitals, a wheelchair, a cart, such as used for logistics, for example hospital logistics or commercial logistics (depending on an example a supermarket trolley), all rolling furniture. Such a rolling object comprises at least two wheels, preferably three or four. Advantageously, at least one wheel, preferably two wheels of the rolling object are idle wheels, in other words they are off-center wheels orientable about a vertical axis. The rolling object is preferably non-motorized.

The electric propulsion system according to the invention comprises:

A frame provided with at least one motorized wheel, that is to say one wheel driven by an electric machine, and at least one non-motorized wheel, preferably two, that is to say not driven (s) by an electric machine,

A handlebar, allowing in particular the handling, movement and orientation of the propulsion system by a user when the handlebars are necessary,

Coupling means of the propulsion system to a rolling object, the coupling means comprise means for gripping and lifting at least one wheel of the rolling object, preferably several wheels of the rolling object, and preferably two wheels of the rolling object. In other words, the coupling means are configured to grip (grip) and lift at least one wheel of the rolling object. By lifting certain wheels of the rolling object, the frictional forces of the hitch assembly are reduced. Thus, the effort required by the user to move the rolling object hitched to the electric propulsion system is reduced.

The coupling of the rolling object to the propulsion system is therefore achieved by at least one wheel of the rolling object, preferably by at least one idle wheel of the rolling object. The rolling object therefore does not need to be adapted for the electric propulsion system, which makes the electric propulsion system universal to various rolling objects.

In the remainder of the description, the terms “longitudinal”, “transverse”, “horizontal” and “vertical” determine the axes and / or directions of the propulsion system when the propulsion system is placed on a flat and level ground ( that is say on a ground without slope, in other words, there are no differences of altitude on the ground) and in operating situation (in particular the wheels of the system are posed on the ground).

The longitudinal direction corresponds to the main direction of movement of the electric propulsion system.

The transverse direction is orthogonal to the longitudinal direction of the system in a horizontal plane.

The vertical direction is orthogonal to the horizontal plane of the system.

According to an alternative, the motorized wheel can be a wheel which can be oriented relative to the chassis along an axis of vertical orientation (the axis being vertical when the system is placed on a flat and level ground). In other words, the motorized wheel can pivot relative to the frame about an axis of vertical orientation. This achievement substantially corresponds to controlling the movement of a pallet truck type system.

Preferably, each motorized wheel is a steerable off-center wheel (also called an idler wheel). The term “steerable off-center wheel” is understood to mean a wheel connected to the chassis by a connecting pivot with a substantially vertical axis, the axis of the wheel not being intersecting with the axis of the pivot allowing the connection between the wheel concerned and the chassis. . Indeed, since no point is common between the axis of the driven wheel and the axis of the pivot which connects it to the frame, the wheel is off-center with respect to the axis of its pivot connecting to the frame. This decentration causes a self-orientation of the driven wheel in the direction of movement. The driven wheel is therefore automatically oriented towards the direction of movement impelled by the user through the driven object or the handlebars. As a result, the system can be steered without having to act on the handlebars. For example, when the system is coupled to a rolling object, an action on the rolling object will orient the propulsion system in the desired direction.

According to one implementation of the invention, the non-motorized wheels can be idle wheels, that is to say off-center wheels that can be oriented around a vertical axis (the axis being vertical when the system is placed on a flat and level ground). In other words, the non-motorized wheels can pivot relative to the frame about an axis of vertical orientation, and the axis of rotation of the wheel can be off-center (non-concurrent) with respect to the axis of vertical orientation. Alternatively, the non-motorized wheels can be orientable wheels around a vertical axis (the axis being vertical when the system is placed on a flat and level ground) in a non-off-center manner. In other words, the non-motorized wheels can pivot relative to the frame about an axis of vertical orientation, and the axis of rotation of the wheel is aligned with this axis of vertical orientation (concurrent with the axis vertical orientation).

The rolling object wheel gripping means enables the wheel to be gripped. For example, these gripping means can comprise a gripper system, a wedging system, magnetic means, adhesive means or any similar system. Advantageously, the gripping means can be movable so as to adapt to all wheel sizes and to any wheel spacing. The movement of the gripping means can be implemented by means of one or more jacks, for example an electric jack, a screw-nut system, a rack-and-pinion system or any similar means.

The wheel lifting means make it possible to raise the wheel of the rolling object, so that this wheel of the rolling object no longer touches the ground, thus facilitating the movement of the rolling object by the propulsion system electric. The mass of the rolling object supported by this wheel is then transferred to the electric propulsion system. This allows in particular to provide the necessary grip for the traction of the motorized wheel of the electric propulsion system. In addition, raising the wheels makes it possible to limit the number of wheels in contact with the ground and thus to limit the friction forces. The lifting can be implemented by means of one or more jacks, for example an electric jack, a screw-nut system, a rack-and-pinion system or any similar means.

According to one embodiment of the invention, the electric propulsion system can be configured so that the non-motorized wheel (s) are located under the rolling object, when the electric propulsion system is coupled to the rolling object. Thus, part of the electric propulsion system does not protrude from the rolling object, making it easier to use in confined spaces.

According to one implementation of the invention, the electric propulsion system can be configured so that the motorized wheel is located outside the rolling object, in the longitudinal direction of the chassis, when the electric propulsion system is hitched to the rolling object. In other words, the part of the frame that supports the motorized wheel protrudes from the rolling object in the longitudinal direction of the frame, when the electric propulsion system is coupled to the rolling object.

Alternatively, the electric propulsion system can be configured so that the motorized wheel is located under the rolling object, when the electric propulsion system is coupled to the rolling object. Thus, part of the electric propulsion system does not protrude from the rolling object, making it easier to use in confined spaces.

According to an implementation of the invention, the motorized wheel can be disposed at one longitudinal end of the frame, and the non-motorized wheels can be disposed at the other longitudinal end of the frame.

The frame can be produced by a mechanically welded assembly.

According to a preferred embodiment, the coupling means are linked to the frame between the motorized wheel and the non-motorized wheel (s). Thus, the longitudinal size of the propulsion system is limited.

According to the invention, the handlebar comprises a connection to the frame and / or to the driven wheel. Thus, an application of a force on the handlebars can drive and / or guide the chassis and / or the driven wheel, and therefore the electric propulsion system.

In addition, the link comprises a means for locking / unlocking the handlebars with respect to the chassis and / or to a driven wheel (or to at least one driven wheel) of the electric propulsion system from at least one position, called "locking position. ", Where the handlebars are fixed to the frame and / or to said driven wheel, towards a position, called" unlocking position ", allowing at least one free movement of the handlebars in a horizontal plane, for example by a rotation of the handlebars according to a vertical axis, relative to the chassis and / or to the driven wheel. Therefore, in the unlocked position, the system is configured so that action on the handlebars cannot cause movement of the system. Of course, the locking / unlocking means also allows the passage from the unlocked position to the locked position.

The locked position of the handlebars allows the electric propulsion system to be moved using the handlebars, in particular during the phase when the rolling object is hitched to the electric propulsion system, and the unlocked position allows only the handlebars to be moved (c ' that is to say without driving the chassis or the driven wheel) to a position making it possible to limit the size of the system, in particular when it is hitched. Thus, the handlebars can be retracted (or erased). This peculiarity is particularly advantageous for moving the hitched system in restricted environments such as hospital beds in corridors and / or elevators. The movement of the coupled propulsion system can be achieved by directly actuating the rolling object, the hospital bed for example, without the need for the handlebars. The movement (also called retracting or erasing) of the handlebar makes it possible to position it in different positions allowing adaptation to different situations in a restricted environment, the movement of the handlebar being independent of the movement of the propulsion system when the locking / unlocking means is in position. unlocking.

The unlocked position is possible, especially when the system is hitched to the rolling object, because the movement of the hitched system can then be done by acting directly on the rolling object (the hospital bed for example). As the handlebars are then no longer necessary to move the assembly, the handlebars can be retracted, in particular by means of the locking / unlocking means.

According to one embodiment, the locking / unlocking means can comprise a single locking position, in which the handlebars can be fixed to the frame.

According to one embodiment, the locking / unlocking means may comprise a single locking position, in which the handlebars can be attached to the driven wheel (for example to the horizontal axis of the driven wheel).

According to a preferred variant, the locking / unlocking means can comprise at least two locking positions. In a first locking position, the handlebars can then be fixed to the frame and in a second locking position, the handlebars can then be fixed to the driven wheel (for example to the horizontal axis of the driven wheel).

The first locking position (handlebars attached to the frame) is advantageous for the docking phase of the electric propulsion system to the rolling object in order to allow the positioning of the electric propulsion system close to the rolling object and thus allow the gripping and lifting at least one wheel of the rolling object. This first locking position can be called "shopping cart" mode. In this position, the handlebars can for example be tilted relative to the vertical axis.

The second locking position (handlebars attached to the driven wheel) allows the system to be used in “scooter” mode, ie with the user standing on the electric propulsion system. It can for example be positioned on a platform or on the chassis. By connecting the handlebars to the driven wheel, the user can steer directly to the electric propulsion system. In this second locking position, the handlebars preferably remain substantially vertical. In other words, it is not tilted with respect to the vertical axis.

This variant with at least two locking positions allows several operations of the electric propulsion system, which further improves the adaptation of the system to different situations.

Figures 10, 11 and 12 illustrate schematically and without limitation an example of a variant allowing two locking positions and one unlocking position.

The electric propulsion system comprises a frame 2 provided with a wheel 3 driven by an electric machine 10 through a transmission means 17 such as a chain or a belt. According to a variant, the driven wheel 3 could be directly driven by the electric machine 10, without the need for transmission means. The driven wheel 3 is fixed to a vertical axis 8, in a pivot connection with the frame 2. The axis 8 is off-center (offset) with respect to the vertical axis passing through the center of the wheel 3. Thus, the wheel 3 is a steerable off-center wheel.

The system also comprises a handlebar 20 connected by an articulation 50 (the articulation 50 can comprise a horizontal axis for example) to a vertical axis 41, the vertical axis 41 being in pivot connection with the frame 2 by means of the interface part 46, the interface part 46 being fixed to the frame 2. The handlebars 20 can thus be inclined relative to the vertical direction thanks to the articulation 50. The vertical axis 41 connected to the handlebars 20 and the vertical axis 8 connected to the driven wheel 3 are substantially coaxial.

In addition, the system comprises a locking / unlocking means 40 allowing two locking positions, one allowing the handlebar 20 to be fixed to the frame 2, the other allowing the handlebar 20 to be fixed to the driven wheel 3, and a position unlocking. The locking / unlocking means 40 notably comprises an interface part 46. The interface part 46 comprises a first coupling part 44.

The locking / unlocking means 40 comprises a dog clutch 42 supporting a connection part 43. It also comprises a second coupling part 45 fixed to a part 47, this part 47 itself being fixed to the vertical axis 8 of the driven wheel 3.

The dog clutch 42 can be positioned on the vertical axis 41, for example at one of its ends. A dog clutch 42 is a device for the direct coupling of two mechanical parts by teeth and / or grooves.

The dog clutch 42 has three positions. As shown in Figure 10, the position of the clutch corresponds to the unlocking position, leaving the connection part 43 free, that is to say not connected to the first coupling part 44 and not connected to the second coupling part 45. In other words, in this position of the dog clutch 42, the handlebar 20 can be retracted, therefore moved without causing the movement of the electric propulsion system. In this unlocked position, the movement of the handlebars 20 is independent of the movement of the electric propulsion system.

FIG. 11 shows the dog clutch 42 in a first locking position. In this case, the position of the dog clutch 42 allows a connection (a locking) of the connection piece 43 to the first coupling piece 44 of the interface piece 46 fixed to the frame 2. Thus, in this first locking position , the handlebar 20 is fixed to the frame 2. This position is advantageously used to allow the electric propulsion system to dock with a rolling object.

FIG. 12 represents the dog clutch 42 in a second locking position. In this case, the position of the dog clutch 42 allows a connection (a locking) of the connection part 43 to the second coupling part 45 of the part 47 fixed to the driven wheel 3. Thus, in this second locking position, the handlebar 20 is fixed to the driven wheel 3. This position is advantageously used for the scooter mode, the user can then use the handlebar 20 to orient the wheels of the propulsion system in scooter mode.

In Figures 10 to 12, the change in position of the dog clutch 42 is represented by a rotation (upwards, for the passage from the position of Figure 10 to that of Figure 11 for example or downwards for the passage of the position of Figure 10 to that of Figure 12 for example) of the connection piece 43 around a horizontal axis of the clutch 42. The change in position of the clutch 42 could just as easily be achieved by a translation of the part connection 43 upwards for connection to the first coupling piece 44 and / or downwards for connection to the second coupling piece 45. Of course, movements combining rotations and translations are also possible for the changes in the position of the dog clutch 42 allowing the engagement of the connection piece 43 to the first coupling piece 44 or to the second coupling piece 45. The dog clutch 42 can for example be actuated in one or other of the three possible positions by a lever (not shown), directly controlled by the user.

For example and in a nonlimiting manner, the locking / unlocking means can also be produced in different ways. It can be a pawn that can move to block or unlock two pieces (like a pin).

The locking / unlocking means can also use friction means. When the two parts are in contact, friction prevents the relative movement of the two parts. When sufficient play exists, the pieces can move relatively to each other. A clutch can, for example, fulfill this function.

The locking / unlocking means can also include magnetic elements. When a magnetic field exists, the relative movement of the two parts is impossible. When the magnetic field is inoperative, parts can then move relatively to each other.

According to a configuration of the system of the invention, the locking / unlocking means may include a first axis. This first axis (vertical for example) can in particular be used to perform a rotation around this first axis (the first axis then serves as an axis of rotation), for example a rotation of the handlebars around the first axis.

Alternatively or additionally, the first axis can be used to carry out a translation along this first axis (the first axis can then be a slide), for example a translation of the handlebars along the first axis.

According to a variant, the first axis can then be fixed to the frame and / or to the driven wheel. When the system is in the unlocked position, the handlebars can then rotate freely around the first axis and / or move freely along the first axis, thus allowing movement of the handlebars, independently of the frame and / or the driven wheel. In the locked position, by preventing the translation and the relative rotation of the first axis and the handlebar, for example and without limitation by a pin which would come to be positioned in the first axis, the movement of the handlebar would cause the movement of the chassis and / or of the driven wheel.

According to an alternative, the first axis can on the contrary be fixed to the handlebars. In this case, the unlocking position would allow a relative rotation of the first axis with respect to the chassis and / or the driven wheel and the locking position, for example by a pin positioned in the axis, would allow a rigid connection of the first axis to the chassis and / or driven wheel. Preferably, the first axis can be vertical (when the propulsion system is placed on a flat and level ground), which can simplify the kinematics of movement of the handlebars for its retraction, in particular on the side of the system (this is i.e. near a transverse end of the system and / or of the rolling object), and limit the overall size of the system.

Advantageously, the coupling means may comprise means for orienting at least one wheel of the rolling object, called a gripped wheel (by the gripping means), in a direction forming a non-zero angle with the direction. longitudinal direction of the chassis of the propulsion system, for example the angle between the orientation of the gripped wheel and the longitudinal direction of the chassis may be at least 10 °. By orienting the wheel of the rolling object in a direction forming a non-zero angle with the longitudinal direction, the longitudinal position of the rolling object is maintained relative to the propulsion system. In other words, a relative longitudinal displacement between the hitched rolling object and the propulsion system is prevented. Preferably, the coupling means may comprise means for orienting the gripped wheel in a direction substantially perpendicular to the longitudinal direction of the chassis of the propulsion system (in other words, the wheel of the rolling object is placed in a parallel direction. or substantially parallel to the lateral direction of the chassis). The longitudinal direction of the chassis may correspond to the direction which connects the motorized wheel to the non-motorized wheel. The longitudinal direction corresponds to the main direction of movement of the electric propulsion system. By substantially perpendicular is meant a direction forming an angle of between 80 and 100 ° with respect to the longitudinal direction. Thus, when propelling the rolling object, at least one wheel of the rolling object is gripped, lifted and oriented in a direction different from the longitudinal direction of the chassis (for example with an angle greater than 10 ° between the orientation of the gripped wheel and the longitudinal direction of the chassis), preferably substantially perpendicular to the longitudinal direction of the chassis. By orienting at least one wheel of the rolling object in a direction different from the longitudinal direction of the chassis, preferably the angle formed being greater than 10 ° and even more preferably close to 90 °, the stability of the coupling formed by the rolling object on the propulsion system is improved. In addition, in this way, the coupling means act on the thinner side of the wheels of the rolling object. This contributes to the coupling means having reduced lateral dimensions compared to the lateral dimensions of the propulsion systems of the prior art (for example those described in patent applications WO 2012/171079 and WO 2013/156030), which facilitates its use in small spaces, such as corridors and elevators. Means of orientation of the wheel of the rolling object can be implemented by moving the gripping means of the wheel. According to one implementation of the invention, the electric propulsion system can perform the following sequence of steps for the coupling: orientation of the wheel of the rolling object in a direction different from the longitudinal direction of the chassis, gripping of the wheel of the rolling object and lifting of the wheel of the rolling object.

According to one aspect of the invention, the system may include a control means for controlling (controlling) the locking / unlocking means. This control means can be mechanical (a cable and / or a spring for example) and / or electric (via an electric cable and an electric control box).

For example, at least one of the lock or unlock actions can be automatic or semi-automatic. For example, in an automatic solution, a pin can be cocked (by a spring for example) to allow automatic locking in a hole when the pin is in front of the hole. Other solutions could allow automatic unlocking.

A pre-armed solution, that is to say ready to lock (or unlock) automatically by a pin armed with a spring for example, is advantageous for a semi-automatic solution. Indeed, this pre-armed solution can be used with a locking control means (a lever for example). By actuating this locking control means, the pre-armed solution is activated (the spring is compressed for example). You can then manipulate the handlebars (by rotating, for example) until the pin is in front of the hole provided. When the pin is in front of the hole, the spring, initially compressed, relaxes and causes the pin to move in the hole. Thus, the locking is achieved. Other solutions could allow semi-automatic unlocking.

When the locking is automatic or semi-automatic, the unlocking can then be controlled by the control means, whether by a mechanical system, a cable for example, or by an electrical system. For example, the user can activate the control means to unlock the system. The control means can be electrically connected or be mechanically connected, by a cable among others, to the locking / unlocking means. Similarly, when the unlocking is automatic or semi-automatic, the locking can then be controlled by the control means. An automatic or semi-automatic locking (or unlocking) action can in particular be implemented on a locking / unlocking means such as a dog clutch.

The user can also control both locking and unlocking by the control means. The control means may for example comprise an electrical box or an electrical or mechanical actuator.

According to an alternative embodiment, when the propulsion system is hitched to the rolling object, the control of the propulsion system is not necessarily done by the handlebars, the control of the movement and of the direction of movement of the hitched system can be achieved. by means of control of the rolling object, for example a handle, a handlebar or the like of the rolling object.

According to an implementation of the invention, the handlebars can be realized in the form of an arm which can be articulated, that is to say of an arm formed of several elements linked to each other. In order to promote the retraction of the handlebars, the connections between the constituent elements of the handlebars can change from a rigid connection to an articulated connection, by locking / unlocking or by locking / unlocking. Different embodiments of this implementation are described in the remainder of the description.

According to one implementation of the system of the invention, the handlebars may in particular be formed by a connecting piece and a connecting rod. In addition, the connecting piece can include the locking / unlocking means and the connecting rod can be articulated with respect to the connecting piece about a first horizontal axis. As a result, the handlebars have an additional articulation, this pivot connection allowing an additional degree of freedom to retract the system. The connecting piece and the connecting rod forming the handlebar can be rigidly fixed to one another in the locked position. The connecting piece can be fixed to the frame and / or to the driven wheel by the handlebar locking / unlocking means. Thus, the handlebars can be moved to a location allowing the easiest possible maneuvering, in particular when using the hitched system. In addition, the handlebars can be moved, during the maneuver, according to the size constraints, and this without having to remove the handlebars. Indeed, a removable handlebar is not necessarily practical because it is then necessary to be able to position the handlebars anywhere, with the risk of forgetting it, or to wear it, which risks causing musculoskeletal disorders. In the unlocked position, the connecting piece may for example be in rotation around the first axis, itself fixed to the frame and / or to the driven wheel. The connecting piece can then comprise a tubular zone surrounding the first axis.

Advantageously, the handlebars may further comprise an operating part and a locking / unlocking means, the locking / unlocking means connecting the operating part and the connecting rod.

The operating part can in particular have the shape of a "T", the vertical bar of the T can then be connected to the connecting rod by the locking / unlocking means, the horizontal bar of the T can then serve as a bar to operate the system. , much like a bicycle handlebar.

The locking / unlocking means makes it possible, in a locking position (or locking), to rigidly fix the operating part to the connecting rod making it possible to ensure the displacement of the propulsion system by the handlebars, and, in an unlocking position ( or locking), to allow relative movement of the operating part to the connecting rod. Preferably, in the unlocked position, it is possible to achieve a relative rotation of the operating part with respect to the connecting rod about an axis (horizontal for example) connecting these two parts, said axis then being positioned at one end of the connecting rod and at the end of the vertical T-bar away from the junction of the vertical T-bar to the horizontal T-bar. Thus, the handlebar has an additional articulation allowing an additional degree of freedom to retract the handlebars when is no longer essential for the user to operate the electric propulsion system or when it is necessary to move it for reasons of available space.

The pivot connection between the connecting rod and the operating part around the axis (horizontal or vertical for example) is advantageous because it can for example be used to position the operating part (for example the horizontal bar of the T) along ( that is to say in the longitudinal direction) of one end (transverse) of the rolling object, of the bed in particular. In other words, the operating part runs along one side of the rolling object. Thus, the retracted handlebars have a reduced bulk and the operating part is in a position which hardly hinders the maneuvers of the system, in particular when it is hitched. The locking / unlocking means allows the connection between the connecting rod and the operating part to pass from a locking position to an unlocking position (and vice versa).

The locking / unlocking means may be equivalent or substantially equivalent to the locking / unlocking means. In other words and in a nonlimiting manner, the locking / unlocking means can comprise a pin moving in an orifice, a friction system such as a clutch and / or a magnetic system.

The locking and / or unlocking control can be activated by user action, for example a mechanical actuator, a pin or via a cable, or by electrical means.

The locking and / or unlocking can also be automatic or semi-automatic, just like the locking and / or unlocking of the locking / unlocking means, for example by a pin cocked to automatically insert itself into a hole, when the orifice is in front of the pin. The pin can for example be armed by a spring.

Advantageously, a control means can control the locking / unlocking means and the locking / unlocking means. Thus, the system is simplified. The user can then order the locking and / or unlocking of the locking / unlocking means and of the locking / unlocking means by a single control means. In addition, this control can be carried out simultaneously. Indeed, unlocking and unlocking are necessary to retract the handlebars. Thus, it makes sense to operate them together, which simplifies the procedure and saves time. Likewise, locking and locking allow the electric propulsion system to be driven by the handlebars. Thus, it is also a good idea to operate them together, which simplifies the procedure for positioning the handlebars and saves time.

According to one embodiment of the system according to the invention, the handlebars may include a control panel. The control panel allows the user to control the system, for example to control the locking and / or unlocking of the locking / unlocking means and / or the locking and / or unlocking of the locking / unlocking means. In other words, the control information entered by the user through the control panel is transmitted to the control means so as to actuate the actuators (locking / unlocking means, blocking / unblocking among others). Preferably, the control panel is positioned at the highest end of the handlebars (that is to say at the end which does not correspond to that which is in connection with the chassis or the driven wheel). For example and preferably, the control panel is positioned on the operating part. Thus, the positioning of the control panel is in an ideal position for the user, the control panel remaining easily accessible. The musculoskeletal disorders to control the system are thus limited. It is in particular practical that the control panel is at a suitable height and easily accessible so as to be able in particular to be able to use the emergency stop command of the system, a command which can be provided on the control panel.

The control panel can also be used to control the electrical machine and / or the coupling means. To control the electric machine, you can control, for example, the ignition, stop, speed and / or torque adjustment of the electric assistance. To control the coupling means, one can for example control the gripping means for gripping the wheel or wheels of the rolling object, the lifting means of the wheel or wheels of the rolling object, and preferably the orientation means of the wheels of the rolling object. These checks may consist of the movement of the elements constituting the coupling means.

The invention also relates to a method for retracting the handlebars of the system described above. By retracting (or erasing) is meant moving to a location that is less inconvenient for the overall footprint of the system, especially when it is hitched to a rolling object, without causing the movement of the electric propulsion system. The retracted handlebar remains positioned on the electric propulsion system. In other words, the handlebars are not removable and can be moved independently of the removable propulsion system. For this process, at least the following steps are carried out:

- The locking / unlocking means are unlocked, the handlebars then being able to move freely relative to the chassis and / or to the driven wheel. For example, the handlebars can at least move by free rotation and / or by free translation relative to the chassis and / or to the driven wheel. Thus, in the unlocked position, the handlebars can be manipulated and positioned in a place which does not obstruct the size of the system (or less annoying it), this manipulation of the handlebars not leading to an orientation and / or a displacement of the chassis or of the driven wheel; - The handlebars are moved to a position suitable for moving the propulsion system, in particular when it is hitched to a rolling object, in a small space. In addition, during this movement of the system, the handlebars can be moved simultaneously and independently of the movement of the system. Indeed, when moving the system, the reduced size may change and thus being able to change the position of the handlebars during handling of the system is an additional advantage.

Preferably, the method for retracting the handlebars can in particular be implemented after having hitched the rolling object to the removable electric propulsion system. This is because the propulsion system has a larger footprint when it is hitched to a rolling object. Therefore, it is particularly advantageous to be able to limit its size when it is hitched.

Advantageously, for the embodiment in which the handlebar comprises a locking / unlocking means of an operating means (the operating part for example), the locking / unlocking means can be unlocked. As a result, the handlebars can have an even smaller size. Preferably, the unlocking of the locking / unlocking means can be carried out simultaneously with the unlocking of the locking / unlocking means. Indeed, the purpose of unlocking and unlocking is to retract the handlebars to minimize the size of the handlebars and therefore of the electric propulsion system. It is therefore possible to actuate them (or control or pilot) simultaneously. In addition, by simultaneous action, the time is reduced, which makes it possible to limit the intervention time and to simplify the handling of the system for the user.

Preferably, for the embodiment in which the handlebar comprises a maneuvering means, after having moved the handlebar, for example on one side of the system (by side means a transverse end of the system) along one side of the bed in particular, the operating part can be rotated. By causing the operating part to pivot relative to the connecting rod, for example around a horizontal or vertical axis, this rotation being made possible in particular by the release of the locking / unlocking means of the system, the operating part can be positioned by so that the bulk of the system is further reduced. The operating part can in particular be positioned along a transverse end of the rolling object (a bed for example), the horizontal bar of the T then being substantially directed in the longitudinal direction. The invention also relates to a method for guiding the removable electric propulsion system by the handlebars. In other words, for this method, the electric propulsion system is driven and directed by the handlebars. This embodiment is particularly useful when the electric propulsion system is not hitched to a rolling object. Indeed, when it is not hitched, the user cannot use the rolling object to orient and direct the electric propulsion system. For this process, at least the following steps are carried out:

- The handlebars are connected (or locked) to the frame and / or to the driven wheel, for example by putting the locking / unlocking means in the locked position. The handlebars are then rigidly fixed to the frame and / or to the driven wheel. Preferably, this locking connection can be made automatically or semi-automatically, for example and without limitation, by a cocked pin, ready to engage in an orifice. Thus, the use of the system is simplified and the user only has to command the unlocking actions;

- We act on the handlebars to move and / or orient the removable electric propulsion system. In fact, once in the locked position, an action on the handlebars generates a direct action on the chassis and / or on the driven wheel which thus makes it possible to drive the electric propulsion system and to steer it.

According to a configuration of the method for guiding the system according to one embodiment of the invention, for which the handlebar comprises a connecting piece and a connecting rod, the operating part can be blocked by the connecting rod by the locking / unlocking means. Thus, the connection of the operating part to the connecting rod, in the locked position, is a rigid connection. Thus, the actions performed by the user on the operating part are transmitted to the connecting rod, and consequently to the electric propulsion system. Preferably, the locking of the operating part with the connecting rod can be carried out simultaneously with the locking of the handlebars to the frame and / or to the wheel driven by the locking / unlocking means. Thus, the operations of using the system are simplified and of shorter duration. For example, the blocking and locking can be controlled by the control means which can receive information from a control panel on which the user records the blocking / locking action. Alternatively, the mechanical locking of the locking / unlocking means or of the locking / unlocking means can cause the other of these means to be locked, the drive can be carried out for example by a cable. The invention further relates to a coupling formed of a rolling object, such as a rolling bed, with a propulsion system according to any one of the combinations of variants described above. The rolling object is coupled to the propulsion system by the coupling means. In other words, at least one wheel of the rolling object is grasped, preferably oriented at a non-zero angle with respect to the longitudinal direction of the chassis (preferably substantially perpendicular to the longitudinal direction of the chassis), and lifted, by the coupling means of the propulsion system.

Figure 1 illustrates, schematically and in a non-limiting manner, an electric propulsion system 1 according to one embodiment of the invention. Figure 1 is a top view of the electric propulsion system 1. The electric propulsion system 1 comprises a frame 2. The x axis corresponds to the longitudinal axis of the frame 2 and to the main direction of movement of the propulsion system 1, and the y axis corresponds to the lateral axis of the frame 2 (the z axis not shown is vertical). The frame 2 supports three wheels (alternatively the frame 2 can include four wheels). The frame 2 supports a wheel 3 (alternatively the frame 2 can support two wheels 3), which is a wheel driven by an electric machine (not shown). The wheel 3 is orientable relative to the frame 2, around a vertical axis 8. At the other end, the frame 2 supports two wheels 4, which are two wheels not driven by an electric machine. The wheels 4 are orientable relative to the frame around vertical axes 9. The electric propulsion system 1 further comprises coupling means 5. According to the illustrated embodiment, the electric propulsion system 1 comprises two means of coupling 5 on either side of the frame in the lateral direction (axis y) in order to achieve the coupling by means of two wheels of the rolling object (not shown). The coupling means 5 are shown in a simplified manner as clamps. The lateral displacement of the coupling means is indicated by a double arrow. This lateral movement can be used for gripping and orienting the wheels of the rolling object. The coupling means 5 are placed, in the x direction, between the motorized wheel 3 and the non-motorized wheels 4.

In addition, the electric propulsion system 1 comprises a handlebar 20, for example in the form of a rod equipped with a handle (not shown), and a connection to the frame 2 by means of a locking means / unlocking 12, making it possible to fix the handlebar 20 to the frame and / or to the driven wheel 3 or, on the contrary, to allow the handlebar 20 to move according to at least one degree of freedom (a rotation or a translation for example) freely to the frame 2 and / or the driven wheel 3. In FIG. 1, the locking / unlocking means is in the unlocking position, in other words the handlebar 20 is not rigidly fixed to the frame 2 or to the driven wheel 3. As the locking / unlocking means is unlocked, it is possible to move the handlebar 20, independently of the frame 2 or the driven wheel 3, for example, the handlebar 20 can be rotated around an axis connected to the frame 2 (or to the driven wheel 3), the axis which may be vertical or substantially vertical.

Figure 1 shows three positions 20 ’, 20” and 20 ”’ of the handlebars in top view, relative to the frame 2, these positions being made possible by the unlocked position. In position 20 ’, when viewed from above, the handlebars 20 extend substantially in the longitudinal direction (x). In the 20 "" position, when viewed from above, the handlebars 20 extend substantially transversely (y). This 20 "position is also called the" side "or" side "position. The handlebars 20 are then said to be "on the side". Position 20 "is an intermediate position allowing to pass from the longitudinal position 20" to the position on the side 20 "" and vice versa.

In addition, the electric propulsion system 1 comprises a support platform 7 (for example of a user). Platform 7 is located at the end of frame 2 which supports non-motorized wheels 4.

FIG. 2 illustrates, schematically and in a nonlimiting manner, an electric propulsion system 1 according to a first variant embodiment of the invention. Figure 2 is a side view of the electric propulsion system 1. The electric propulsion system 1 comprises a frame 2. The x axis corresponds to the longitudinal axis of the frame 2 and to the main direction of movement of the propulsion system , and the z axis corresponds to the vertical axis of the frame 2, the y axis (not shown) corresponds to the transverse axis. Frame 2 supports three wheels. The frame 2 supports a wheel 3, which is a wheel driven by an electric machine 10 by means of a drive 17, for example a belt or a chain (alternatively the electric machine 10 can be connected directly to the wheel 3). The wheel 3 is orientable relative to the frame 2, around a vertical axis 8. The electric machine 10 can be secured to the pivot 8 of the motorized wheel 3. At the other end, the frame 2 supports two wheels 4, which are two wheels not driven by an electric machine. The wheels 4 are orientable relative to the frame 2 around vertical axes 9. The electric propulsion system 1 further comprises coupling means 5. According to the illustrated embodiment, the electric propulsion system 1 comprises two means of 'coupling 5 on either side of the frame 2 in the lateral direction (axis y) in order to achieve the coupling by means of two wheels of the rolling object (not shown). Coupling means 5 are shown schematically as clamps. The vertical displacement of the coupling means 5 is indicated by a double arrow. This vertical movement of the coupling means allows in particular the lifting of the wheels of the rolling object. The coupling means 5 are placed, in the x direction, between the motorized wheel 3 and the non-motorized wheels 4.

In addition, the electric propulsion system 1 comprises a handlebar 20, for example in the form of a rod equipped with a handle (not shown) connected to the frame 2 by a link comprising a locking / unlocking means 12. This means locking / unlocking 12 allows the handlebars 20 to be fixed to a vertical axis 35, the vertical axis 35 being rigidly fixed to the frame (alternatively, this vertical axis 35 could be fixed to the horizontal axis of the driven wheel 3). The handlebar 20 is shown in a first position 20 ", corresponding to that of Figure 1, then shown in top view and in a 20" "position, corresponding to that of Figure 1 shown in top view. To allow this change of position of the handlebars relative to the frame, the locking / unlocking means 12 is in the unlocked position.

In addition, the electric propulsion system 1 comprises a battery 11. The battery 11 is placed on the frame 2 near the electric machine 10 and the motorized wheel 3.

FIG. 3 illustrates, schematically and in a nonlimiting manner, an electric propulsion system 1 according to a second variant embodiment of the invention. Figure 3 is a side view of the electric propulsion system 1. The electric propulsion system 1 comprises a frame 2. The x axis corresponds to the longitudinal axis of the frame 2 and to the main direction of movement of the propulsion system , and the z axis corresponds to the vertical axis of the frame 2. The frame 2 supports three wheels. The frame 2 supports a wheel 3, which is a wheel driven by an electric machine 10 by means of a drive 17, for example a belt or a chain. The wheel 3 is orientable relative to the frame 2, around a vertical axis 8. The electric machine 10 can be secured to the pivot 8 of the motorized wheel 3. At the other end, the frame 2 supports two wheels 4, which are two wheels not driven by an electric machine. The wheels 4 are orientable relative to the frame around vertical axes 9. The electric propulsion system 1 further comprises coupling means 5. According to the illustrated embodiment, the electric propulsion system 1 comprises two means of coupling 5 on either side of the frame in the lateral direction (axis y) in order to achieve the coupling by means of two wheels of the rolling object (not shown). The coupling means 5 are shown in a simplified manner as clamps. The vertical displacement of the coupling means 5 is indicated by a double arrow. This vertical movement of the coupling means allows in particular the lifting of the wheels of the rolling object. The coupling means 5 are placed, in the x direction, between the motorized wheel 3 and the non-motorized wheels 4.

In addition, the propulsion system 1 comprises a handlebar 20, for example in the form of a rod equipped with a handle (not shown) connected to the vertical orientation axis 8 of the motorized wheel 3 by means of a link comprising a locking / unlocking means 12. The handlebar 20 is shown in the position 20 ′, that is to say in the so-called “longitudinal” position. In this position 20 ', it is possible to lock the locking / unlocking means 12, so as to move and orient the frame 2 and the driven wheel 3 by means of the handlebar 20. In the locked position, the handlebar 20 is in fact fixed. rigidly to the vertical axis 8, itself fixed rigidly to the horizontal axis of the driven wheel 3.

In addition, the electric propulsion system 1 comprises a battery 11. The battery 11 is placed on the frame 2 near the non-motorized wheels 4.

Figure 4 illustrates, schematically and in a non-limiting manner, an electric propulsion system 1 according to one embodiment of the invention, coupled to a rolling object 13. Figure 4 is a top view of the electric propulsion system 1 and of the rolling object 13. The embodiment of FIG. 4 corresponds to the embodiment of FIG. 1. The rolling object 13 can be of any type, in particular a rolling bed. The rolling object comprises two wheels 14, arbitrarily called rear wheels, and two wheels 15, arbitrarily called front wheels. The electric propulsion system 1 comprises a frame 2. The x axis corresponds to the longitudinal axis of the frame 2 and to the main direction of movement of the propulsion system, and the y axis corresponds to the lateral axis of the frame 2 The frame supports three wheels. The frame 2 supports a wheel 3, which is a wheel driven by an electric machine (not shown). The wheel 3 is orientable relative to the frame 2, around a vertical axis 8. At the other end, the frame 2 supports two wheels 4, which are two wheels not driven by an electric machine. The wheels 4 are orientable relative to the frame 2 around vertical axes 9. The electric propulsion system 1 further comprises coupling means 5. According to the illustrated embodiment, the electric propulsion system 1 comprises two means of 'hitch 5 on either side of the frame in the lateral direction (axis y) in order to achieve the hitch by means of two rear wheels 14 of the rolling object. The coupling means 5 are shown in a simplified manner as clamps. The rear wheels 14 of the rolling object are placed in the grippers, and are oriented along the y axis, that is to say along an axis perpendicular to the longitudinal axis (x axis) of the frame 2. In addition, the front wheels 15 of the rolling object are free and not coupled.

The electric propulsion system 1 also comprises a handlebar 20, for example in the form of a rod equipped with a handle (not shown) articulated with respect to the frame 2. The handlebar 20 is connected to the frame 2 by a link comprising a locking / unlocking means. The 20 ', 20 ”and 20”' positions are three possible positions of the handlebar 20 when the locking / unlocking means is in the unlocked position, thus allowing the movement (one rotation in particular) of the handlebar 20 independently of the frame 2. Position 20 'corresponds to a position where, in top view, the handlebar 20 extends substantially in the longitudinal direction while the 20 "position corresponds to a position where, in top view, the handlebar 20 extends substantially in the longitudinal direction. transverse direction, the handlebar 20 is then sideways in the 20 ”'position. This 20 "" position can allow the handlebars 20 to be retracted to the side. Indeed, in position 20 "", in top view, the handlebar 20 substantially runs along one end of the rolling object 13, shown by the dotted lines, for example the headboard. Position 20 "is an intermediate position to move from the longitudinal position 20" to the position on the side 20 "" and vice versa.

When the handlebars are sideways in the 20 "" position, the handlebars, when viewed from above, are oriented in a direction substantially perpendicular to the longitudinal direction. In other words, it is oriented in a transverse (or lateral) direction. In this position on the 20 "" side, the handlebars protrude, in the transverse direction, over the side of the rolling object 13.

In addition, the electric propulsion system 1 comprises a support platform 7 (for example of a user). The platform 7 is located at the end of the frame 2 which supports the non-motorized wheels 4. For the embodiment of FIG. 4, the coupling means 5, the non-motorized wheels 4, the platform 7, and a major part of the frame 2 are located below the rolling object. Only the motorized wheel 3 and the handlebar 20 can protrude from the rolling object 13 in the longitudinal direction x of the frame 2.

Figures 13 to 15 show, in a schematic and non-limiting manner, variants of the propulsion system coupled to the rolling object, in top views. The references identical to those in Figure 4 correspond to the same elements and will therefore not be redetailed.

In FIGS. 13 to 15, once coupled to the rolling object 13, the propulsion system 1 is essentially under the rolling object 13. In other words, the major part of the system of propulsion 1 is positioned under the rolling object 13, after having been hitched to it. Only part of the handlebars protrudes from the longitudinal bulk (in 20 'and 20 ”positions) and / or the transverse bulk (in 20”' position). Once hitched, the motorized wheel 3 is positioned under the rolling object 13.

In figure 13, in the position of the handlebars on the 20 ”'side, the handlebars protrude from a transverse end of the rolling object 13. It therefore protrudes on the side of the rolling object, the protrusion being limited to a small amount. part of the handlebars. The handlebars can include an operating part (not shown). When used, this operating part may in particular have a substantially longitudinal main direction in the 20 ”'position so as to run along the side of the rolling object 13 (the side being a transverse end of the rolling object 13) .

In Figure 14, the handlebars can also be positioned in a 20 "" position forming an angle greater than 90 ° to the direction of the longitudinal position of the 20 "handlebars. Depending on the length of the handlebars and the transverse length of the rolling object, by allowing the handlebars to rotate more than 90 ° in relation to the 20 ”'position, it is possible to limit the protrusion of the handlebars on the side of the rolling object.

The handlebars include an operating part 28. This operating part 28 has in particular a substantially horizontal part (a horizontal or substantially horizontal bar, for example) on which the user can place his hands to drive and orient the propulsion system. The operating part 28 can rotate in the horizontal plane (around a vertical axis for example), according to the rotation R1 so as to be positioned in the longitudinal direction, along a transverse end of the rolling object 13, as in FIG. 15. The transverse end corresponds to one side of the rolling object 13 which may for example be the edge of a bed.

When the operating part 28 is positioned along the side of the rolling object 13 as in FIG. 15, the transverse size of the electric propulsion system 1 coupled to the rolling object 13 is limited, in particular compared to the transverse size of FIG. 14. The articulation of the handlebars with the maneuvering part therefore makes it possible to reduce the size.

FIG. 5 illustrates, schematically and in a nonlimiting manner, a first embodiment of a connection of the handlebar to the frame of a system according to the invention. In this figure, an axis 21, substantially vertical, is fixed to the frame 2.

This axis 21 is linked to the handlebars 20 by means of a locking / unlocking means. The locking / unlocking means is shown in the locked position 22 "on the diagram on the left and in the unlocked position 22" on the diagram on the right. Thus, in the diagram on the left, when the locking / unlocking means is locked, the handlebar 20 is then rigidly fixed to the axis 21 and therefore to the frame 2.

On the contrary, in the diagram on the right, the locking / unlocking means is unlocked and thus allows a relative rotation of the handlebars 20 around the axis 21. In other words, in the unlocked position, the connection between the handlebars 20 and the axis 21 is a pivot link or a sliding pivot link.

For this example, the handlebars 20 has a first tubular part 20a, this first tubular part 20a being coaxial with the axis 21, thus allowing the pivot connection in the unlocked position. The handlebar 20 also has an inclined part 20b, facilitating the manipulation of the electric propulsion system in the locked position. The first tubular part 20a and the inclined part 20b can be rigidly fixed to each other or connected by a hinge, so as to improve the ability to retract in the unlocked position.

FIG. 6 illustrates, schematically and in a non-limiting manner, an embodiment of a connection of the handlebars to the driven wheel of a system according to the invention.

In this figure, an axis 21, substantially vertical, is fixed to a wheel 3. The wheel 3 is driven by an electric machine 10 by means of a drive means 17 such as a chain or a belt. The axis 21 is in a pivot connection with respect to the frame 2.

This axis 21 is linked to the handlebars 20 by means of a locking / unlocking means, materialized in a simplified and non-limiting manner by a pin 32, which is shown in the locked position in the figure. This pin 32 can move in the direction d, so as to allow unlocking or on the contrary to move it from the unlocking position to the locking position. The connection between the handlebars 20 and the axis 21 is here represented by a ball joint composed of an internal part 23b of spherical shape and of an external part 23a of spherical shape. The internal part 23b is housed in the external part 23a so as to form a ball joint. The internal part 23b is fixed to the handlebars 1; the external part 23a is fixed to the axis 21. In the locked position as shown on FIG. 6, the pin 32 prevents the relative rotation of the internal part 23b with respect to the external part 23a.

The axis 21 is fixed to the wheel 3, for example by the horizontal axis of the wheel 3. Thus, in the locked position, an action on the handlebar 20 is transmitted to the wheel 3. The user can then use the handlebars to move the electric propulsion system.

Figures 7, 8 and 9 correspond to side views of an electric propulsion system 1 according to the invention for three positions corresponding respectively substantially to positions 20 ", 20" and 20 "" of Figures 1 and 4.

In these three figures, the references corresponding to those of the preceding figures correspond to the same elements and will not be redetailed.

In these figures, the handlebars are made up of several elements, in particular a connecting piece 25, a connecting rod 26 and an operating piece 28.

The connecting piece 25 can in particular comprise a locking / unlocking means for connecting the handlebars to the frame, such as a pin, potentially armed to lock automatically, or a clutch or other friction elements, or even and without limitation, by an electrically controlled connection.

The connecting piece 25 is connected to the connecting rod 26, at one end of the connecting rod 26, by a pivot connection about a first substantially horizontal axis 30.

The other end of the connecting rod 26 is connected to the operating part 28 by a locking / unlocking means, which can be of the same type of operation as the locking / locking means. In other words, the locking / unlocking means can include a pin, possibly to arm automatically (with a spring for example), a clutch or an electrical connection. In the locked position, the operating part 28 is fixedly connected to the connecting rod 26: no relative movement between these two parts is then possible.

In the unlocked position, the operating part 28 can rotate freely relative to the connecting rod 26 about a second horizontal axis 29.

The operating part 28 has substantially the shape of a T with a straight portion, called the vertical bar of the T, corresponding to the part 27, and a substantially horizontal bar, this horizontal bar serving as a handle for the user. One end of the vertical bar of the T 27 is connected to the connecting rod 26 by the locking / unlocking means.

The dotted line axis ar corresponds to the vertical axis passing through the axis of the connecting piece 25. In FIG. 7, the handlebar is substantially in position 20 ′ shown in top view in FIG. 1. Thus , the horizontal bar of the operating part extends in the transverse axis, perpendicular to the plane of the figure. Axes 29 and 30 also extend along the transverse axis. This position 20 ′ can allow manipulation of the electric propulsion system 1 via the handlebars, in particular by the operating part 28.

In FIG. 8, the handlebars are in the position corresponding substantially to position 20 ”of FIG. 1 in top view. Thus, the horizontal bar of the operating part 28 extends in a direction forming a non-zero angle with the longitudinal direction and with the transverse direction. The axes 29 and 30 extend substantially in the same direction as the horizontal bar of the actuator 28.

In figure 9, the handlebars are on the side. In top view, it is therefore substantially in the 20 "’ position of Figure 1. In side view, the handlebars are therefore oriented along the ar axis. The horizontal bar of the operating part 28 is then substantially in the longitudinal direction. For example, it can be positioned along one side of the rolling object (the bed, for example).

The horizontal axes, referenced 29 and 30 in Figures 7 and 8, are substantially longitudinal (and therefore not visible in Figure 9 because hidden by the other parts of the handlebars).

Claims

1. Removable electric propulsion system for a rolling object (13), said propulsion system (1) comprising a frame (2) provided with at least one wheel driven (3) by an electric machine (10), and of at least one non-driven wheel (4), a handlebar (20) and coupling means (5) of said propulsion system to said rolling object (13), said coupling means (5) comprising means for gripping and for lifting of at least one wheel of said rolling object (13), said handlebar (20) comprising a connection to said frame (2) and / or to said driven wheel (3), characterized in that said connection comprises locking means / unlocking (12, 40) of said handlebar (20) relative to said frame (2) and / or to a driven wheel (3) from at least one locking position where the handlebar (20) is fixed to said frame (2) and / or or to said driven wheel (3), this at least one locking position (22 ') of said handlebar (20) making it possible to move the electric propulsion system (1) thanks to the said handlebar (20), towards an unlocking position (22 ”) allowing at least one free movement of said handlebar (20) relative to said frame (2) and to said driven wheel (3).

2. System according to claim 1, wherein said locking / unlocking means (12, 40) comprises an axis, preferably, said axis being fixed to the frame (2) or to said driven wheel (3).

3. System according to one of the preceding claims, wherein said locking / unlocking means (12, 40) comprises two locking positions, a first locking position connecting said handlebar (20) to said frame (2) and a second position locking connecting said handlebar (20) to said driven wheel (3), preferably the locking / unlocking means comprising a dog clutch (42).

4. System according to one of the preceding claims, wherein said coupling means (5) comprise orientation means of at least one wheel of said rolling object (13) in a direction forming a non-zero angle with the direction. longitudinal (x) of said frame of said propulsion system (1), preferably said coupling means (5) comprise means for orienting at least one wheel of said rolling object (13) in a direction substantially perpendicular to the direction longitudinal (x) of said frame (2) of said propulsion system (1).

5. System according to one of the preceding claims, wherein said electric propulsion system (1) comprises control means for controlling said locking / unlocking means (12, 40).

6. System according to one of the preceding claims, wherein said handlebar (20) comprises an arm, preferably the arm being articulated.

7. System according to claim 6 for which the arm comprises a connecting piece (25) and a connecting rod (26), said connecting piece (25) comprising said locking / unlocking means (12, 40), said connecting rod (26). ) being articulated with respect to said connecting piece (25) about a first horizontal axis (30).

8. System according to claim 7, wherein said handlebar (20) comprises an operating part (28) and a locking / unlocking means, said locking / unlocking means connecting said operating part (28) and said connecting rod (26). ).

9. System according to claims 5 and 8, wherein said control means controls said locking / unlocking means (12, 40) and said locking / unlocking means, preferably simultaneously.

10. System according to one of claims 8 or 9, wherein said locking / unlocking means comprises at least two configurations, a first configuration in which said operating part (28) is in a pivot connection about a second axis ( 29) relative to said connecting rod (26), and a second configuration in which said operating part (28) is rigidly fixed to said connecting rod (26).

11. System according to one of the preceding claims, wherein said handlebar (20) comprises a control panel.

12. Method for retracting said handlebar (20) of an electric propulsion system (1) according to one of the preceding claims in which at least the following steps are carried out:

- Said locking / unlocking means (12, 40) are unlocked, said handlebar (20) then being able to move freely relative to said frame (2) and / or to said driven wheel (3);

- said handlebar (20) is moved.

13. The method of claim 12, wherein the steps are performed after having hitched said rolling object (13) to said removable electric propulsion system (1).

14. Method according to one of claims 12 or 13 for an electric propulsion system (1) according to one of claims 8 to 11, for which one unlocks said locking / unlocking means, preferably simultaneously with the unlocking of said means. locking / unlocking (12, 40).

15. The method of claim 14 for which, after moving said handlebar (20), said operating part (28) is pivoted.

16. A method for guiding the removable electric propulsion system (1) according to one of claims 1 to 11 by said handlebar (20) in which at least the following steps are carried out:

- said handlebar (20) is connected to said frame (2) and / or to said driven wheel (3), preferably automatically or semi-automatically, by said locking / unlocking means (12, 40), said handlebar (20) being rigidly fixed to said frame (2) and / or to said driven wheel (3);

- Acting on said handlebar (20) to move and / or orient the removable electric propulsion system (1).

17. The method of claim 16, comprising an electric propulsion system (1) according to one of claims 8 to 11, for which said operating part (28) is blocked to said connecting rod (26) by said locking means / unlocking, preferably simultaneously with the locking of said handlebar (20) to said frame (2) and / or to said driven wheel (3) by said locking / unlocking means (12, 40).