Wheelchair comprising a manual actuator

Abstract

A wheelchair (10) comprising a frame (12); at least one wheel system (20) comprising a main shaft (22), a wheel (24) rotatably mounted relative to said main shaft, and a handrim (28) coupled to the wheel; at least one braking system (30, 130) comprising a first braking portion (38, 138) rotationally coupled to the wheel and a second braking portion (34, 134), the braking system being configured to bring the first braking portion and the second braking portion into cooperation in order to brake the rotation of the wheel, said second braking portion being fixed relative to the wheelchair frame during braking; and at least one hand actuator (50, 501, 502, 503, 504, 505), extending radially relative to a main axis of the main shaft, on an external side of the wheel.

Description

[0001] Description Title of the invention: Wheelchair comprising a hand actuator

[0002] Technical Field

[0003] The present invention relates to the technical field of wheelchairs, and more specifically to the field of wheelchairs equipped with braking systems to slow the rotation of the wheels of the chair.

[0004] Wheelchairs traditionally consist of a frame and two wheel systems. The wheel systems each comprise a main shaft mounted to the chair frame and a wheel pivoting relative to the main shaft. The wheel systems further comprise a handrim, usually toroidal in shape, attached to the wheel and capable of being manipulated by the user to rotate the wheel, for forward or reverse movement.

[0005] On most common wheelchairs, handrims also serve to slow the rotation of the wheels. To do this, the user rubs their hand against the rotating handrim to slow it down. However, it is understandable that the user risks burning their hand due to the friction, so this braking solution is not satisfactory.

[0006] Less commonly, some wheelchairs are equipped with a wheel braking solution, thus avoiding the user having to brake the wheel by rubbing their hand on the handrim. The present invention concerns this category of wheelchairs equipped with a wheel braking solution.

[0007] Prior art

[0008] Wheelchairs are known which are equipped with a disc brake type braking system, which makes it possible to brake the rotation of a braking disc linked in rotation to the wheel when it is activated. These chairs are equipped with an operating handle mounted on the frame of the chair, approximately at the height of the user's knees.

[0009] A disadvantage of these wheelchairs is that the operating handle is difficult for the user to access, as they must lean forward to reach it, even though it is generally preferable to lean backward to maintain better balance, particularly on slopes. Operating the handle is particularly tricky, and this wheelchair is not very ergonomic and may even be dangerous for the user, who may have difficulty braking the wheels effectively or risk tipping forward when trying to reach the operating handle. Another disadvantage is that the user must release the handrim in order to operate such an operating handle. This results in a loss of control over the wheelchair's trajectory.

[0010] Another braking solution involves combining brake levers, similar to bicycle brake levers, with handles for pushing the wheelchair located at the rear of the chair. These brake levers can only be operated by the caregiver pushing the wheelchair. This solution is not satisfactory for the person sitting in the wheelchair, who cannot access the brake levers and therefore cannot brake independently.

[0011] Wheelchairs such as that described in US 3,869,146 are also known, which are equipped with a wheel drive system. The drive system comprises a drive lever pivotally mounted relative to the main shaft and which can be actuated in order to rotate the wheel. This drive lever, which is rotatably connected to the wheel, is further equipped with a braking pad. The braking lever can be pushed towards the wheel, so as to bring the braking pad into contact with the handrim and thus brake the wheel by friction.

[0012] This wheelchair has the disadvantage of making braking the wheel particularly difficult since braking is performed between the drive lever and the handrim of the wheelchair. In other words, during braking, the braking resistance force is transferred to the lever, then to the user's arm. Indeed, the user must exert a significant force on the drive lever to push it towards the wheel and to keep the pad of the drive lever in contact with the handrim, in order to generate effective and lasting friction on the handrim. The user must also, and above all, exert a significant force on the drive lever in contact with the handrim in order to counter the force exerted by the rotating wheel on said lever, and thus prevent said drive lever from pivoting relative to the main shaft.

[0013] It is understandable that users of such wheelchairs, who are in a situation of disability and may suffer from an inability to exert significant effort with their arms, encounter significant difficulties in effectively braking the rotation of the wheel of such a wheelchair. As a result, the user's safety is compromised. In addition, with this solution, braking is achieved by means of a drive lever which also allows the wheelchair wheel to rotate. In addition to being poorly ergonomic and ineffective in driving the wheelchair wheels to rotate, such drive levers are also incompatible with conventional drive solutions via a handrim, because they prevent the user from manipulating the latter. In other words, these braking solutions are unsatisfactory and involve the use of a drive lever which is not very ergonomic and which complicates the driving of the wheelchair.

[0014] Statement of the invention

[0015] An aim of the present invention is to provide a wheelchair which overcomes the aforementioned drawbacks.

[0016] To this end, the invention relates to a wheelchair comprising: a frame; at least one wheel system comprising: a main shaft having a main axis and being configured to be mounted to the frame of the chair; a wheel rotatably mounted relative to said main shaft about said main axis, the wheel having an outer side and an inner side which faces the frame when the wheel system is mounted to the frame; a handrail linked to the wheel, for driving said wheel forward or backward;at least one braking system comprising a first braking portion rotatably connected to the wheel and a second braking portion, the braking system being configured to bring the first braking portion and the second braking portion into cooperation to brake the rotation of the wheel relative to the main shaft, when said braking system is actuated, said second braking portion being fixed relative to the frame of the chair during braking; and at least one hand actuator for actuating the braking system, said hand actuator extending radially relative to said main axis, on the outer side of the wheel.;

[0017] The frame of the chair is also called the chassis.

[0018] The chair advantageously comprises two wheel systems, configured to be mounted on either side of the frame. The wheels pivot relative to the frame and allow the chair to be moved forward or backward. The frame advantageously comprises a seat, on which the user can sit, and a backrest.

[0019] The main shaft of the wheel system is preferably configured to be removably mounted to the wheelchair frame. Without limitation, when mounted to the wheelchair frame, the main shaft may be rotationally locked or freely rotatable relative to said frame.

[0020] In a non-limiting manner, the main shaft may comprise a tubular element and a cylindrical body engaged inside the tubular element, the tubular element and the cylindrical body extending along the main axis. The cylindrical body is advantageously configured to cooperate with the frame of the wheelchair for mounting the main shaft to the frame. The tubular element is advantageously axially fixed, considered along the main axis, relative to the cylindrical body. In a non-limiting manner, said cylindrical body may be free to rotate relative to the tubular element.

[0021] The wheel of the wheel system advantageously comprises a hub pivotally mounted relative to the main shaft. The hub advantageously extends along said main axis. Preferably, the wheel further comprises a rim connected to the hub, for example by spokes. The wheel advantageously comprises a tire mounted on said rim.

[0022] The handrail is advantageously attached to the wheel. The handrail advantageously has the shape of a torus attached to the rim of the wheel. The handrail extends from the outside of the wheel.

[0023] The hand actuator constitutes a means of actuating the braking system. Like a handle for actuating the brakes of a bicycle, it allows braking to be triggered but is not configured to generate braking directly, for example by rubbing itself directly on the wheel. The hand actuator extends transversely to the main axis. Preferably, but in a non-limiting manner, the hand actuator is mounted on the main shaft. The hand actuator advantageously extends radially relative to the main shaft. Preferably, the angular position of said hand actuator considered relative to the main axis is adjustable.

[0024] The positioning of the hand actuator on the outside of the wheel makes it particularly accessible for the user whose hand is in contact with the handrim when driving the wheel forward or backward. Thanks to the invention, the user can easily manipulate the hand actuator, without moving his hand, or by moving it very slightly, from the handrim. Control of the trajectory of the chair is therefore improved. This positioning of the hand actuator makes the chair all the more ergonomic.

[0025] Thanks to the invention, the user has easy access to the hand actuator and can manipulate it with less effort, in order to perform braking. Braking operations are therefore facilitated and user safety is enhanced. In particular, the user can operate the braking system without leaning forward, which reduces the risk of tipping and falling.

[0026] Preferably, the hand actuator can be manipulated by the user whose hand rests on the handrim. Preferably, the hand actuator extends proximate to the handrim. Preferably, the hand actuator has a distal end that extends proximate to the handrim. In a non-limiting manner, the hand actuator may take the form of a lever, a disc, a portion of a disc, a braking handle or any other form allowing its manipulation in an easy manner for a user seated in the wheelchair. In a non-limiting manner, the actuation of the braking system may be achieved by moving the hand actuator as a whole or by moving a portion of said hand actuator. Preferably, but in a non-limiting manner, the wheel system comprises said hand actuator.

[0027] Furthermore, the chair according to the invention makes it possible to easily drive the wheel into rotation by means of the handrail, without the hand actuator according to the invention disturbing the manipulation of said handrail.

[0028] Preferably, but not limited to, said hand actuator cooperates directly with the braking system. Alternatively, the wheelchair may comprise an actuating member, for example an actuating cable or a cam, extending between said hand actuator and said braking system, to transfer to the braking system the actuating force exerted on the hand actuator.

[0029] In a non-limiting manner, the hand actuator makes it possible to move the first braking portion and / or the second braking portion. Preferably, but in a non-limiting manner, said hand actuator cooperates with one of said first and second braking portions.

[0030] Without limitation, the braking system may be configured to move the first braking portion toward the second braking portion when actuated, and / or to move the second braking portion toward the first braking portion when actuated.

[0031] In a non-limiting manner, the first braking portion may be a portion of the wheel, for example a portion of the wheel hub. Alternatively, said first braking portion may be separate from the wheel. Preferably, said first braking portion is locked in rotation relative to the wheel. In a non-limiting manner, the first braking portion may be radially movable relative to the wheel, considered relative to the main axis. In a non-limiting manner, the first braking portion may have the form of a friction element, for example a braking pad, configured to be moved in order to cooperate with the second braking portion.

[0032] Alternatively, in a non-limiting manner, the first braking portion may be fixed relative to the wheel. In a non-limiting manner, the first braking portion may be a brake disc rotatably connected to the wheel or a friction part fixed to the hub.

[0033] Without limitation, the first braking portion may be part of a part or a complete part.

[0034] Without limitation, the second braking portion may be a portion of the wheelchair frame or a portion of the wheel system, separate from the frame. The second braking portion is separate from the wheel. Without limitation, the second braking portion may be movable relative to the first braking portion. For example, the second braking portion may be a braking pad, or a braking shoe, configured to be moved or deformed so as to come into contact with the first braking portion or a portion of a braking caliper configured to rub on a braking disc connected to the wheel. Without limitation, the second braking portion may be a part of a part or a complete part.

[0035] Advantageously, said second braking portion is separate from the hand actuator.

[0036] When the second braking portion is fixed relative to the frame, said second braking portion cannot pivot relative to the frame. Therefore, the cooperation of the second braking portion, fixed relative to the frame, and the first braking portion makes it possible to brake the rotation of the wheel, in particular by friction. Preferably, the wheelchair comprises a fixing means configured to fix said second braking portion relative to the frame during braking.

[0037] Without limitation, the second braking portion is fixed relative to the frame at least during braking. The second braking portion may be fixed relative to the frame temporarily, for example only during braking, or permanently, in which case the second braking portion is fixed relative to the frame at all times.

[0038] In document US 3,869,146, the wheelchair user must exert a significant force on the drive lever to bring the pad of the drive lever into contact with the handrim, to maintain friction between this pad and the handrim, and above all to prevent the drive lever from pivoting given the force exerted by the rotating wheel on the latter. Braking is then carried out between the drive lever and the wheel and all braking forces must be absorbed by the user's arm manipulating the drive lever. The wheel braking operation is therefore particularly difficult. In other words, the braking force necessary to brake the wheel corresponds directly to the force exerted by the user on the drive lever.

[0039] On the contrary, it is understood that the braking system of the chair according to the invention makes it possible to perform the braking between a first braking portion linked in rotation to the wheel and a second braking portion which is fixed relative to the frame, at least during braking. The braking is therefore carried out between on the one hand the wheel, via the first braking portion, and on the other hand the frame, via the second braking portion. The majority of the braking forces are transmitted to the frame via the second braking portion. In other words, the braking system of the chair according to the invention is configured to perform the braking between the wheel and the frame, in particular via the first and second braking portions. According to the invention, the braking is not carried out between the hand actuator and the wheel.

[0040] The hand actuator of the wheelchair according to the invention has the function of actuating the braking system and triggering the braking. However, it does not constitute a braking portion and braking the wheel does not require exerting a significant force on the hand actuator, for example in order to press it against the wheel or to prevent it from pivoting. In other words, the braking forces are not transmitted from the wheel to the user's arm via this hand actuator but from the wheel directly to the frame of the wheelchair. The force that the user must exert to manipulate the hand actuator and thus perform the braking is therefore particularly reduced.

[0041] The force required to be exerted on the hand actuator to actuate the braking system is advantageously much lower than the braking force generated by the braking system to brake the rotation of the wheel.

[0042] Preferably, the hand actuator does not contact the wheel when the braking system is actuated. Preferably, the hand actuator is held away from the wheel when the braking system is actuated.

[0043] The braking of the wheel is preferably progressive braking. That is to say that the braking force making it possible to brake the rotation of the wheel, and in particular the friction force between the first and second braking portions, can be adjusted by adapting the force exerted on the hand actuator. Preferably, the force exerted by the first braking portion on the second braking portion, respectively the force exerted by the second braking portion on the first braking portion, is proportional to the force exerted by the user on the hand actuator. Without departing from the scope of the invention, and in a non-limiting manner, the force between the first and second braking portions and the force exerted on the hand actuator can be linked by a linear or exponential relationship.

[0044] Preferably, the braking system is configured to establish friction between the first braking portion and the second braking portion when actuated.

[0045] Preferably, said second braking portion is integral with the wheelchair frame during braking. By interlocking, it is meant that the second braking portion and the frame form a solid and inseparable unit during braking. When the second braking portion is integral with the frame, said second braking portion is fixed relative to the frame. It cannot then pivot relative to the frame. Therefore, the cooperation of the second braking portion, integral with the frame, and the first braking portion makes it possible to brake the rotation of the wheel, in particular by friction. In a non-limiting manner, the second braking portion is integral with the frame at least during braking. The interlocking between the second braking portion may be temporary, for example only during braking, or permanent, in which case the second braking portion is integral with the frame at all times.

[0046] Advantageously, said hand actuator extends inside a cylindrical volume defined by an inner radius of the handrail and extending along said main axis. A first advantage is to reduce the size of the hand actuator by preventing it from extending above the handrail, or even above the wheel. Furthermore, the palm of the user's hand usually rests on the handrail when handling the latter. Since the hand actuator extends inside said cylindrical volume, it is consequently arranged under the palm of the user's hand and can be reached and handled by the user's fingers, substantially without moving his hand. Actuation of the braking system is therefore facilitated.

[0047] Preferably, said hand actuator comprises at least one manipulation portion remote from the main axis. The manipulation portion makes it possible to easily manipulate said hand actuator and therefore facilitates braking.

[0048] Preferably, but not limited to, the handling portion comprises a handle. The handling portion is preferably located proximate the handrail.

[0049] According to an advantageous variant, said hand actuator has the form of a lever comprising a main body extending radially relative to the main axis, said manipulation portion being located at a distal end of said main body. An advantage is to reduce the weight and size of the hand actuator, while allowing easy manipulation of the latter. Preferably, said main body is mounted on the main shaft.

[0050] According to another advantageous variant, the hand actuator comprises a disc portion extending radially relative to said main axis, said manipulation portion being located in a peripheral part of said disc portion. This form of hand actuator has the advantage of increasing the surface area of ​​the manipulation portion and thus allowing the user to reach the latter more easily. In addition, said disc portion constitutes a protective screen for the user's hands, preventing his fingers from getting caught in the spokes of the wheel.

[0051] Without limitation, said hand actuator may comprise a complete disc.

[0052] Preferably, said hand actuator is configured to take at least one active configuration in which it actuates said braking system, and a rest configuration in which it does not actuate the braking system. Preferably, the active configuration is an unstable configuration. Also, the user must maintain the hand actuator in the active configuration in order to perform the braking. Preferably the chair, more preferably the hand actuator, comprises a return element configured to return the hand actuator from the active configuration to the rest configuration.

[0053] Preferably, the transition from the rest configuration to the active configuration is achieved by moving the hand actuator. Alternatively, and without departing from the scope of the invention, the transition from the rest configuration to the active configuration can be achieved by moving a portion of the hand actuator.

[0054] In a non-limiting manner, the hand actuator can take an infinite number of intermediate configurations between said braking configuration and said active configuration. Each of said intermediate configurations advantageously corresponding to a distinct braking force exerted by the brake system between the first and second braking portions, for braking the wheel. One advantage is to make the braking progressive.

[0055] According to an advantageous variant, said hand actuator comprises a main body and an actuating handle, of the bicycle brake lever type, movable relative to the main body, said hand actuator being brought from the rest configuration to the active configuration by moving the actuating handle relative to the main body.

[0056] Preferably, said hand actuator is configured to remain stationary relative to the frame of the wheelchair when it is held in the rest configuration. In other words, when the hand actuator is in the rest configuration, it remains fixed and static, in particular relative to the frame of the wheelchair. It is understood that as long as the user does not bring the hand actuator into the active configuration, said hand actuator remains in this rest configuration and does not move relative to the frame of the wheelchair. One advantage is to prevent the hand actuator from moving, for example pivoting with the wheel, when the chair is moving. Therefore, it is particularly easy for the user to reach the hand actuator which remains in a fixed and constant position relative to the frame of the wheelchair, and therefore relative to the user's arm. The hand actuator is advantageously not rotationally linked to the wheel.

[0057] Preferably, said hand actuator is configured to move from the rest configuration to the active configuration by pivoting about a pivot axis. One advantage is to be able to easily bring the hand actuator into the active configuration, by exerting a push or a pull on the hand actuator.

[0058] Advantageously, said pivot axis is parallel to said main axis, preferably coincident with said main axis. One advantage is to allow the user to easily bring the hand actuator into the active configuration, and therefore to perform braking, by pushing or pulling on the hand actuator. The movement to be made to bring the hand actuator into the active configuration is particularly instinctive. Preferably, the hand actuator is configured to move from the rest configuration to the active configuration by pivoting in a direction opposite to the direction of rotation of the wheel when moving forward. Without departing from the scope of the invention, the hand actuator may be configured to move from the rest configuration to the active configuration by pivoting in a direction corresponding to the direction of rotation of the wheel when moving forward.

[0059] Preferably configured to transition from the rest configuration to the active configuration by pivoting relative to the main shaft.

[0060] Preferably, said hand actuator is configured to move from the rest configuration to the active configuration by tilting towards the wheel. According to this embodiment, the hand actuator is brought into the active configuration by tilting towards the wheel and therefore towards the inside of the chair. To do this, the user pushes the distal end of the hand actuator towards the wheel.

[0061] Advantageously, the braking system further has a parking configuration in which it blocks the rotation of the wheel, the hand actuator being configured to further assume a parking configuration in which it brings the braking system into the parking configuration, said hand actuator being fixed relative to the frame of the chair when it is in said parking configuration. An advantage is to prevent the movement of the chair and allow it to be parked when the user does not wish to move forward or backward, for example during a transfer operation to a bed or a chair. The hand actuator is advantageously placed in the parking configuration when the chair is not moving.

[0062] It is understood that the parking configuration is a stable configuration for the hand actuator. In other words, from the parking configuration, it is necessary to exert a force on the hand actuator in order to bring it back into the rest configuration. The parking configuration is a stable configuration for the braking system.

[0063] Preferably, the hand actuator is configured to be brought into the parking configuration by moving said hand actuator beyond a hard point, i.e. by exerting a force on the hand actuator greater than a predetermined force threshold.

[0064] Preferably, in the parking configuration, the braking system is configured to press the first braking portion and the second braking portion against each other to block rotation of the wheel relative to the main shaft. Said second braking portion is advantageously fixed relative to the frame of the chair when the braking system is in the parking configuration.

[0065] Advantageously, starting from the rest configuration, said hand actuator is configured to be brought into the active configuration by moving said hand actuator in a first direction, for example by pivoting in a first direction of rotation, and to be brought into the parking configuration by moving said hand actuator in a second direction, for example by pivoting in a second direction of rotation, opposite to the first direction, beyond a hard point.

[0066] By hard point, it is meant that a force must be exerted on said hand actuator greater than a predetermined force threshold in order to bring the latter into the parking configuration. One interest is to prevent the user from placing the hand actuator in the parking configuration, and therefore the braking system in the parking configuration, by mistake.

[0067] Preferably, starting from the rest configuration, said hand actuator is configured to be brought into the parking configuration only by moving said hand actuator in said second direction. Moving the hand actuator in the first direction only allows the latter to be brought into the active configuration and the braking system into the actuated configuration, regardless of the force exerted on the hand actuator. The hand actuator cannot be brought into the parking configuration by moving in said first direction. An advantage is to further reduce the risk of bringing the hand actuator into the parking configuration accidentally. Advantageously, said first and second braking portions are located inside a cylindrical volume defined by an inner radius of the handrail and extending along said main axis.One interest is to reduce the size of the braking system and therefore the total size of the chair and the overall width of the chair.

[0068] Preferably, said wheel comprises a hub, said first and second braking portions extending inside said hub. One advantage is to further reduce the size of the braking system. Another advantage is to protect said first and second braking portions, in particular against humidity, splashes of water and mud and dust. In a non-limiting manner, said first braking portion may be a portion of the hub, for example an inner face of the hub or a friction part fixed relative to the hub and extending inside the hub. The second braking portion may be a braking shoe or a braking pad, for example configured to come into contact with the inner face of the hub or a friction part fixed to the hub.Preferably, said second braking portion is configured to move radially, considered relative to the main axis, towards the first braking portion, when the braking system is actuated.

[0069] Preferably, when actuated, said braking system is configured to bring the second braking portion into contact with the first braking portion and / or to bring the first braking portion into contact with the second braking portion so as to generate friction between said first and second braking portions, whereby the rotation of the wheel relative to the main shaft is braked.

[0070] Advantageously, the braking system comprises a cam secured to the lever and extending along the main axis, said cam being configured to bring the first braking portion and the second braking portion into cooperation. Said cam is advantageously cylindrical. It is advantageously configured to pivot around the main axis when the braking system is actuated. The cam preferably extends around the main shaft. Said cam is advantageously configured to push the second braking portion towards the first braking portion.

[0071] According to a preferred embodiment, the first braking portion is fixed relative to the hub, the braking system comprising a cam cooperating with the hand actuator and pivotally mounted relative to the main shaft, said cam having a variable profile considered according to its circumference, said second braking portion being located at the periphery of said cam, said cam being configured to pivot about the main axis when the braking system is actuated, so that said cam pushes said second braking portion radially against said first braking portion. It is understood that the second braking portion is pushed so as to come into contact with the first braking portion in order to perform friction braking between said first and second braking portions. The first braking portion is located around the second braking portion.

[0072] In a non-limiting manner, in this embodiment, the first braking portion may be a portion of the hub, for example an inner face of the hub, or a friction part separate from the hub but fixed inside the hub. In a non-limiting manner, said second braking portion part may be a braking shoe configured to move or deform radially, in order to come into contact with said first braking portion.

[0073] In this embodiment, the braking system advantageously comprises at least one roller disposed between said cam and said second braking portion, the roller being configured to push radially on the second braking portion when the cam pivots around the main axis, in response to the actuation of the braking system.

[0074] Preferably, said cam comprises at least one longitudinal groove configured to receive said roller when said braking system is placed in the parking configuration. When the hand actuator is moved beyond the hard point and is brought into the parking configuration, the cam pivots in the around the main axis and the roller is brought into said groove. It is understood that as long as said roller is received in the groove, the braking system is maintained in the parking configuration.

[0075] Preferably, said second braking portion comprises an elastically deformable tubular part arranged around said cam. It is understood that said tubular part deforms elastically towards the first braking portion, taking into account the thrust force of the cam, and rubs on said first braking portion to carry out the braking.

[0076] Preferably, when elastically deformed, the tubular part tends to return to its undeformed configuration. When said hand actuator is not actuated, the tubular part returns to its undeformed configuration and exerts a force on the cam, for example via said roller, which has the consequence of causing said cam to pivot towards its initial position. The hand actuator being advantageously integral with said cam, it is also rotated about the main axis and also returns to its rest configuration.

[0077] Said second braking portion then advantageously forms a return element making it possible to return the hand actuator to the rest configuration.

[0078] Advantageously, said second braking portion is a portion of the wheelchair frame or a portion of the wheel system. It is understood that when the second braking portion is a portion of the frame, the braking is carried out directly between the first braking portion and the frame. Alternatively, when the second braking portion is a portion of the wheel system, the latter is fixed relative to the frame during braking, so that the braking is carried out indirectly relative to the frame, via said second braking portion.

[0079] Preferably, said wheel system comprises said second braking portion, the wheel system further comprising a locking part configured to cooperate with a portion of the frame of the chair, to block the rotation of the second braking portion relative to the frame in at least one direction of rotation. In this configuration, it is understood that the second braking portion is a portion of the wheel system and not of the frame.

[0080] The said locking piece allows the second braking portion to be fixed in relation to the frame, during braking.

[0081] Advantageously, the locking part cooperates directly or indirectly with the second braking portion. Preferably, the second braking portion is fixed relative to the locking part.

[0082] The locking part is advantageously configured to cooperate with a locking element of the wheelchair frame, for example a pin, for locking said locking part in rotation.

[0083] Preferably, the locking part comprises a disc mounted on the main shaft and extending radially relative to the main axis, at least one orifice being provided in said disc, said orifice being configured to receive a portion of the frame for locking the locking part in rotation.

[0084] Advantageously, said second braking portion is integral with the main shaft, said locking part being configured to block the rotation of the main shaft relative to the frame of the chair in at least one direction of rotation.

[0085] In this non-limiting embodiment, said locking part makes it possible to secure the main shaft to the frame of the chair during braking. It is further understood that the braking is carried out between the first braking portion and the main shaft. In other words, the braking is carried out indirectly between the wheel and the frame, via the main shaft.

[0086] Advantageously, said first and second braking portions are axially fixed along said main axis. One advantage is to improve the cooperation of the first and second braking portions to achieve braking.

[0087] Preferably, the chair further comprises a protective element extending radially relative to the main axis and disposed between the hand actuator and the wheel. This protective element makes it possible to protect the user's fingers by preventing them from accessing the spokes of the wheel and becoming trapped there. This further improves user safety.

[0088] The protective element advantageously has the shape of a disc or a cone, for example a flattened cone.

[0089] Brief description of the drawings

[0090] The invention will be better understood on reading the following description of embodiments of the invention given as non-limiting examples, with reference to the appended drawings, in which:

[0091] [Fig. 1] Figure 1 shows a wheelchair according to the invention, comprising a first variant of a hand actuator;

[0092] [Fig. 2] Figure 2 shows the wheel system and hand actuator of the chair of Figure 1, the latter being in the resting configuration;

[0093] [Fig. 3]Figure 3 is a longitudinal sectional view of the wheel system of Figure 2;

[0094] [Fig. 4]Figure 4 illustrates a first variant of a braking system for a wheelchair according to the invention, the hub having been removed;

[0095] [Fig. 5]Figure 5 shows the braking system of Figure 4 with the brake shoe removed;

[0096] [Fig. 6]Figure 6 is a cross-sectional view of the braking system of Figure 4, in an unactuated configuration;

[0097] [Fig. 7]Figure 7 illustrates the movement in the active configuration of the hand actuator of the chair of Figure 1; [Fig. 8]Figure 8 is a cross-sectional view of the braking system of Figure 4, in an actuated configuration;

[0098] [Fig. 9]Figure 9 illustrates a second variant of a hand actuator of an armchair according to the invention;

[0099] [Fig. 10] Figure 10 illustrates a third variant of a hand actuator of an armchair according to the invention;

[0100] [Fig. ll]Figure 11 illustrates a fourth variant of a hand actuator of an armchair according to the invention

[0101] [Fig. 12]Figure 12 illustrates the movement in the active configuration of the hand actuator of Figure 11;

[0102] [Fig. 13]Figure 13 illustrates a fifth variant of a hand actuator of an armchair according to the invention;

[0103] [Fig. 14]Figure 14 illustrates a sixth variant of a hand actuator of an armchair according to the invention;

[0104] [Fig. 15]Figure 15 is a cross-sectional view of a second variant of a braking system of an armchair according to the invention;

[0105] [Fig. 16]Figure 16 shows the hand actuator in parking configuration;

[0106] [Fig. 17] Figure 17 is a cross-sectional view of the braking system of Figure 15, in a parking configuration; and

[0107] [Fig. 18]Figure 18 is a sectional view of a third variant of a braking system for an armchair according to the invention.

[0108] Description of the embodiments

[0109] The invention relates to a wheelchair comprising at least one wheel system, a braking system and a hand actuator for actuating the braking system.

[0110] Figure 1 illustrates a wheelchair 10 according to the invention. This wheelchair comprises a frame 12 having a seat 14 and a backrest 16. The wheelchair 10 comprises front wheels 18 of reduced size.

[0111] The chair further comprises a first wheel system 20 and a second wheel system 20'. Since the first and second wheel systems 20, 20' are substantially identical, only the first wheel system 20 will be described subsequently.

[0112] As illustrated in Figure 2, the first wheel system 20 comprises a main shaft 22 extending along a main axis X. As illustrated in the sectional view of Figure 3, the main shaft comprises, in this non-limiting example, a tubular element 21 and a cylindrical body 23 engaged inside the tubular element 21. The tubular element 21 is integral with the cylindrical rod 23. In this non-limiting example, the main shaft 22 comprises a quick-mounting device 25 for removably mounting the first wheel system to the frame 12 of the wheelchair. The quick-mounting system 25 here comprises a connecting rod extending inside the main shaft.

[0113] The first wheel system 20 further comprises a wheel 24 comprising a hub 26 and a rim 27 connected to the hub by spokes. The wheel 24, by means of the hub 26, is pivotally mounted relative to the main shaft 22, about the main axis X. The wheel 24 has an inner side 24a, which faces the frame and is directed towards the inside of the wheelchair. The wheel 24 further has an outer side 24b, opposite the inner side and directed towards the outside of the chair. The tubular element 21 of the main shaft 22 extends essentially inside the hub 24 of the wheel 26.

[0114] Referring again to Figure 2, it can be seen that the wheel system 20 further comprises a toroidal-shaped handrail 28, fixed to the rim 27 of the wheel and linked to said wheel 24. The handrail 28 can be manipulated by the user in order to drive the wheel 24 in rotation in forward or reverse gear.

[0115] According to the invention, the wheelchair 10 further comprises a braking system 30, a first non-limiting variant of which will be described with reference to FIGS. 3 to 7. The wheelchair also comprises a second braking system for braking the wheel of the second wheel system 20'. This second braking system being identical to the braking system 30 of the wheel 24 of the first wheel system 20, it will not be described in detail. The braking system 30 makes it possible to brake the wheel 24 of the first wheel system 20 relative to the main shaft 22.

[0116] In Figure 2, it can be seen that the wheelchair further comprises a hand actuator 50, for actuating the braking system 30. Figure 2 illustrates a first, non-limiting, variant of the hand actuator of the wheelchair according to the invention. Other variants of the hand actuator 50 will be illustrated with reference to Figures 9 to 14. In this non-limiting example, the hand actuator 50 has the shape of a lever. It comprises a main body 54. It is mounted to the main shaft 22 and extends radially relative to the main shaft and relative to the main axis X. The hand actuator 50 extends from the outer side 24b of the wheel, so that the wheel 24 is located between said hand actuator 50 and the frame 12 of the wheelchair, when the wheel system is mounted to the wheelchair.

[0117] The hand actuator 50 has a proximal end 50a mounted to the main shaft 22 and a distal end 50b located near the handrail 28. Said distal end 50b comprises a manipulation portion 52 for manipulating the hand actuator. Said manipulation portion is distant from the main axis X and is located near the handrail 28.

[0118] As can be seen, said hand actuator 50 extends inside a cylindrical volume V defined by an internal radius R of the handrail 28 and extending along said main axis X. The hand actuator therefore proves to be compact and easily accessible for the user.

[0119] The hand actuator 50 is configured to assume at least a rest configuration, in which it does not actuate the braking system 30, and an active configuration, in which it actuates the braking system 30. In FIG. 2, the hand actuator 50 is in the rest configuration. As long as it is maintained in the rest configuration, said hand actuator remains stationary relative to the frame 12 of the wheelchair. In other words, it is not rotated with the wheel 24 of the wheel system 20.

[0120] In this non-limiting example, the hand actuator 50 is pivotally mounted relative to the main shaft 22, around a pivot axis Y which here coincides with the main axis X, between said rest configuration and said active configuration. Here, the hand actuator 50 can be brought into the active configuration by pivoting in a first direction which is opposite to the forward rotation direction of the wheel 24, around said pivot axis Y.

[0121] With reference to Figures 3 and 7, we will now describe a first non-limiting variant of the braking system 30 of the wheelchair 10 according to the invention. In this non-limiting example, and as can be seen in the longitudinal sectional view of Figure 3, the braking system 30 is here arranged inside the hub 26 of the wheel 24. The braking system 30 comprises a cam 32, of cylindrical and substantially tubular shape, extending along the main axis X.

[0122] As can be seen in the view of Figure 5, in which the parts surrounding the cam have been hidden, said cam 32 has a first end portion 32a which is fixed to the proximal end 50a of the hand actuator 50. In the sectional view of Figure 6, it can be seen that said cam

[0123] 32 has a variable profile depending on its circumference. More precisely, said cam has a portion of reduced diameter defined by two cam hollows

[0124] 33 formed axially on said cam 32 and diametrically opposite each other. These cam recesses have substantially the shape of slightly curved flats.

[0125] Referring again to the sectional view of Figure 3, as well as to the perspective view of Figure 4, it can be seen that the braking system 30 further comprises a braking shoe 34 of tubular shape and arranged around the cam 32. The shoe 34 extends along the main axis X. The braking shoe 34 is deformable. The braking system further comprises two rollers 36 visible by transparency in Figure 4. They are arranged between the cam 32 and the braking shoe 34. The rollers 36 are arranged on either side of the cam 32. They are of cylindrical shape and extend parallel to the main axis X.

[0126] The braking system 30 further comprises a friction piece 38, of tubular shape and extending along the main axis X. The friction piece 38 extends around the jaw 34. It is formed of steel. The friction piece is fixed inside the hub 26 and is integral with the latter, and therefore with the wheel 24. Said friction piece 38 constitutes a first braking portion of the braking system, linked in rotation to the wheel 24. In this non-limiting example, the first braking portion, constituted by the friction piece 38, extends inside the hub 26. It further extends inside said cylindrical volume V defined by the internal radius R of the handrail 28.

[0127] Furthermore, said braking jaw 34 constitutes a second braking portion of the braking system 30.

[0128] As can be seen in Figure 3, or in the perspective view of Figure 4, showing in particular the braking shoe 34, the wheel system 20 further comprises a locking piece 60. The locking piece 60 is secured to the tubular element 21 of the main shaft 22. The locking piece 60 and the hand actuator 50 extend on either side of the hub 26. The braking shoe 34 is here secured to said locking piece 60, by means of a securing piece 64. The securing piece 64 cooperates with the braking shoe 34 and the locking piece 60, so as to prevent the braking shoe from rotating relative to said locking piece.

[0129] In this example, the locking part 60 has substantially the shape of a disc, or even the shape of a daisy, in which oblong orifices 62 are formed. The locking part 60 is configured to cooperate with a portion of the frame 12 of the wheelchair 10 to block the rotation of the locking jaw 34 relative to the frame. More precisely, a pin 13 of the frame engages in one of the orifices of the locking part 60 to block the rotation of the latter. Therefore, the locking jaw 34, forming a second braking portion, is fixed relative to the frame and secured to the frame 12. In this non-limiting example, the braking jaw 34 is fixed relative to the frame during braking but also when not braking.

[0130] We will now describe the steps of braking the wheel 24 relative to the main shaft 22. Initially, the wheelchair is moving forward, so that the wheel 24 rotates in a direction corresponding to the forward movement. As illustrated in Figure 2, the hand actuator is in the rest configuration, so that it remains stationary relative to the frame 12 of the wheelchair.

[0131] As can be seen in Figure 6, since the hand actuator 50 is in the rest configuration, the braking system is not actuated. Each of the rollers 36 is arranged opposite one of the cam recesses 33, so that they do not push on the braking shoe 34. The braking shoe 34 is therefore not in contact with the friction piece 38. In other words, the first braking portion and the second braking portion are not brought into cooperation, and the wheel 24 can pivot freely.

[0132] As illustrated in Figure 7, in order to brake the rotation of the wheel 24, the user pivots the hand actuator 50, relative to the main shaft 22, around the main axis X, in a first direction of rotation opposite to the direction of rotation of the wheel 24. Here, the hand actuator is pivoted by approximately a quarter of a turn. The hand actuator 50 is thus brought from the rest configuration, illustrated in Figure 2, to the active configuration, illustrated in Figure 7.

[0133] The hand actuator 50 is configured to actuate the braking system 30 when it is brought from the rest configuration to the active configuration. More specifically, as seen in FIG. 8, the pivoting of the hand actuator 50 directly causes the cam 32, which is integral with said hand actuator, to pivot about the main axis X in said first direction of rotation. The rollers 36 are then brought opposite a portion of the cam 32 of larger diameter. The cam 32 then pushes the rollers 36 radially, towards the braking shoe 34. The rollers then exert a radial thrust force on the braking shoe 34 which is pushed and deforms elastically towards the friction part 38. The braking shoe 34 thus deformed then takes a tubular shape of substantially oval section.

[0134] The braking shoe 34 then comes into contact with the inner face of the friction piece 38. As described previously, the friction piece 38 is connected in rotation to the wheel so that it pivots with the wheel. The braking shoe 34 is fixed relative to the frame 12, taking into account the rotational blocking operated by the blocking piece 60 and the securing piece 64. Consequently, friction is generated between said pivoting friction piece 38 and said braking shoe 34 fixed relative to the frame. This leads to braking the rotation of the hub and therefore of the wheel 24 relative to the main shaft 22. In other words, the actuation of the braking system 30 here makes it possible to bring the second braking portion, constituted by the braking shoe 34, into contact with the first braking portion, constituted by the friction piece 38, and thus generate friction between these two braking portions.

[0135] Since the braking shoe 34 is fixed relative to the frame 12, most of the braking forces are transmitted to the frame. The force that the user must exert to bring the hand actuator 50 into the active configuration and to actuate the braking system 30 is particularly reduced. The hand actuator 50 is an actuating element for only triggering the braking. On the other hand, it does not constitute a braking element and does not generate a friction force by itself. In other words, the braking is carried out between the wheel 24 and the frame 12, in particular via the first and second braking portions and not between the hand actuator 50 and the wheel.

[0136] In this non-limiting example, the braking shoe 34 also constitutes a return element making it possible to return the hand actuator to the rest configuration when the latter is not activated. More precisely, the braking shoe 34, elastically deformed by the radial thrust force exerted by the cam 32 and the rollers, tends to return to its initial tubular shape of circular section. Also, when the hand actuator 50 is no longer actuated, the braking shoe 34 returns the rollers 36 opposite the cam recesses 33 and pivots the cam 32 in a second direction of rotation, until it returns to its initial position. The hand actuator 50 is jointly rotated in said second direction of rotation, taking into account the return force exerted by the braking shoe 34, and is returned to the rest configuration. Consequently, the actuation of the braking system 30 is interrupted when the hand actuator is not activated.

[0137] Figure 9 illustrates a second variant of a hand actuator 50i of a wheelchair according to the invention. The hand actuator 50i here comprises a radial mounting portion 54i mounted on the main shaft 22. The hand actuator further comprises a manipulation portion 52 comprising a disc portion 52i extending at the periphery of said radial mounting portion 54i. Said disc portion 52i extends radially relative to the main axis X. The disc portion 52i is distant from the main axis X. Said disc portion 52i also makes it possible to protect the user by preventing them from trapping their fingers in the spokes of the wheel 24. In this embodiment, the hand actuator 50i is also pivotally mounted relative to the main shaft 22, around a pivot axis Y coinciding with the main axis X, between the rest configuration and the active configuration.

[0138] The manipulation portion 52 further comprises a plurality of protrusions 53 arranged on the circumference of said disc portion 52i and projecting axially from said peripheral disc, towards the outside of the wheelchair. These protrusions 53 can be easily grasped, pulled or pushed by the fingers of the user and thus allow the hand actuator 50i to be easily pivoted from the rest configuration to the active configuration.

[0139] Figure 10 illustrates a third variant of a hand actuator 502 of a wheelchair according to the invention. According to this variant, the hand actuator 502 has the shape of a lever. It comprises a main body 542 mounted on the main shaft 22 and extending radially relative to the latter, and a handling portion 52 comprising a handle 522 located at the distal end of the main body 542. In this embodiment, the hand actuator 502 is also pivotally mounted relative to the main shaft 22, around a pivot axis Y coinciding with the main axis X, between the rest configuration and the active configuration. Figure 11 illustrates a fourth variant of a hand actuator 502 of a wheelchair according to the invention. According to this variant, the hand actuator

[0140] 503 also has the shape of a lever. It comprises a main body 543 mounted to the main shaft 22 and a manipulation portion 52 comprising an oval-shaped handle 523 located at the distal end of the main body 543.

[0141] As illustrated in the sectional and side view of Figure 12, in this embodiment, the hand actuator 5O3 is pivotally mounted relative to the main shaft 22, about a pivot axis Y' perpendicular to the main axis X. The hand actuator 5O3 is configured to be brought into the active configuration by pushing it or by tilting it towards the outer side 24b of the wheel 24, as shown by the arrow in this figure.

[0142] Figure 13 illustrates a fifth variant of a hand actuator 504 of a wheelchair according to the invention. According to this variant, the hand actuator

[0143] 504 comprises a disc portion 524 forming substantially a quarter of a disc. Said disc portion 524 is mounted on the main shaft 22 and extends radially relative to said main axis X and to the main shaft 22. In this embodiment, the hand actuator 504 is also pivotally mounted relative to the main shaft 22, around a pivot axis Y coincident with the main axis X, between the rest configuration and the active configuration.

[0144] The hand actuator 504 further comprises a manipulation portion 52 comprising a peripheral portion 544 of said disc portion. The manipulation portion 52 further comprises a plurality of protrusions 53 arranged on the peripheral portion 544 of the disc portion 524 and projecting axially from said peripheral portion 524, towards the outside of the wheelchair. These protrusions 53 can be easily grasped, pulled or pushed by the fingers of the user and thus allow the hand actuator 504 to be easily pivoted from the rest configuration to the active configuration. Said disc portion 524 further makes it possible to protect the fingers of the user by preventing them from being able to reach the spokes of the wheel 24.

[0145] Figure 14 illustrates a sixth variant of a hand actuator 50s according to the invention. In this embodiment, the hand actuator 50s comprises a main body 54s and a manipulation portion 52 formed at the distal end of the main body 54s. The manipulation portion comprises a brake lever. The brake lever comprises a support 57 and an actuating handle 58 movable relative to the support 57. The hand actuator 50s is configured to move from the rest configuration to the active configuration by pressing the actuating handle 58 in order to move it relative to the support 57, in the manner of a bicycle brake handle. In this embodiment, the hand actuator is fixed relative to the main shaft 22.

[0146] The hand actuator 50s is advantageously configured to actuate the braking system 30 via an actuating cable (not shown) connected to the actuating handle 58 of the braking lever and to said braking system 30.

[0147] Figures 15, 16 and 17 illustrate a second variant of the braking system 30 according to the invention, capable of further assuming a parking configuration when the hand actuator 50 is brought into a parking configuration, illustrated in Figure 16. As can be seen in the sectional view of Figure 15, in this variant, two longitudinal grooves 35, diametrically opposed, are formed in the peripheral face of the cam 32. These grooves are each configured to receive one of the rollers 36 when the braking system 30 is in the parking configuration.

[0148] In a non-limiting manner, in Figure 15, said cam 32 is pivoted in a first direction of rotation, in response to a pivoting in said first direction of rotation of the hand actuator 50, relative to the main shaft 22, from the rest configuration into the active configuration. As described previously, this pivoting of the cam 32 causes the actuation of the braking system 30 and the braking of the wheel by bringing the second braking portion, constituted by the braking shoe 34, into contact with the first braking portion, constituted by the friction part 38. The movement of the hand actuator 50 in this first direction of rotation does not allow it to be brought into a parking configuration, and does not bring the braking system 30 into a parking configuration, regardless of the force exerted on said hand actuator.

[0149] In order to bring the braking system 30 into the parking configuration and as illustrated by the transition from Figure 2 to Figure 16, the user brings the hand actuator 50 from the rest configuration to the parking configuration, the chair being substantially stationary. To do this, the hand actuator 50 is here pivoted in a second direction of rotation, opposite to the first direction of rotation and indicated by an arrow. Consequently, the cam 32 is driven in said second direction of rotation, around the main axis X. The rollers 36 are then brought closer to the grooves 35. By continuing to pivot the hand actuator 50, and by exerting a force greater than a predetermined force threshold in order to pass a hard point, the rollers 36 are brought inside said grooves 35. As illustrated in FIG. 17, the braking system 30 is then placed in the parking configuration while the hand actuator 50 is in the parking configuration.The rollers 36 then prevent the cam from pivoting, so that these parking and parking configurations are stable. In addition, the braking shoe 34 then presses on the inner face of the friction part 38, which generates a blocking of the rotation of the hub and therefore of the wheel 24 relative to the main shaft 22.

[0150] In order to bring the braking system 30 into the non-actuated configuration and to bring the hand actuator 50 into the rest configuration, it is necessary to exert a force on the hand actuator 50, in the first direction of rotation, in order to extract the rollers 36 from the grooves 35 and to pass the hard point again.

[0151] Figure 18 illustrates a third variant of a braking system 130 of the wheelchair according to the invention. In this variant, the braking system 130 is also essentially integrated into the hub. The braking system 130 comprises a cam 132, of cylindrical shape, extending along the main axis X and fixed to the hand actuator 50. The cam 132 has at its end a threaded portion.

[0152] The braking system further includes a coupling member 136 having a threaded portion engaging the threaded portion of the cam. The coupling member further includes a tapered coupling surface. The braking system also includes two brake pads 134 located in the hub. Each brake pad 134 includes a tapered surface configured to cooperate with the tapered coupling surface of the coupling member 136.

[0153] The braking pads 134 comprise a braking surface 135 configured to cooperate by friction with an inner surface 138 of the hub 26, when the braking system 130 is actuated. The hub, and more precisely said inner surface 138 of the hub, constitutes a first braking portion linked to the wheel 24.

[0154] To brake the wheel, the user brings the hand actuator 50 into the active configuration, which has the effect of driving the cam 132 in rotation about the main axis X. The coupling member 136, the threaded portion of which is engaged with the threaded portion of the cam 132, is driven in axial translation towards the braking pads 134. The braking pads are then brought into cooperation with a plug 164 cooperating with a freewheel 166. The freewheel 166 is locked in rotation relative to the main shaft 22 and to the locking part 60 in the braking direction. Therefore, the braking pads 134 are locked in rotation during this actuation of the braking system 130 and are therefore fixed relative to the frame 12 of the wheelchair. The braking pads 134 constitute a second braking portion, fixed relative to the frame, during braking.

[0155] The braking pads are sandwiched between the coupling member 136 and the plug 164. The coupling member 136 then exerts a radial force on the braking pads 134 which move apart and are moved radially towards the hub 26. The braking surface 135 of the braking pads then comes into contact with the inner surface 138 of the hub 26, thus braking the wheel 24. The braking is therefore carried out by bringing the braking pads 134, forming a second braking portion, into frictional cooperation with the inner surface 138 of the hub 26, forming a first braking portion.

Claims

Claims 1. Wheelchair (10) comprising: a frame (12); at least one wheel system (20) comprising: a main shaft (22) having a main axis (X) and being configured to be mounted to the frame of the chair; a wheel (24) rotatably mounted relative to said main shaft about said main axis, the wheel having an outer side (24b) and an inner side (24a) which faces the frame when the wheel system is mounted to the frame; a handrail (28) connected to the wheel, for driving said wheel forward or backward;at least one braking system (30,130) comprising a first braking portion (38,138) rotatably connected to the wheel and a second braking portion (34,134), the braking system being configured to bring the first braking portion and the second braking portion into cooperation to brake the rotation of the wheel relative to the main shaft, when said braking system is actuated, said second braking portion being fixed relative to the frame of the chair during braking; and at least one hand actuator (50, 501,502,503, 504,50s) for actuating the braking system, said hand actuator extending radially relative to said main axis, on the outer side of the wheel.; 2. Wheelchair according to claim 1, wherein said hand actuator (50, 501, 502, 503, 504, 50s) extends inside a cylindrical volume (V) defined by an inner radius of the handrim (28) and extending along said main axis.

3. Wheelchair according to claim 1 or 2, wherein said hand actuator (50, 501, 502, 503, 504, 50s) comprises at least one manipulation portion (52) distant from the main axis (X).

4. Wheelchair according to claim 3, wherein said hand actuator (50,502,503,50s) has the form of a lever comprising a main body (54,542,543,54s) extending radially with respect to the main axis (X), said manipulation portion (52) being located at a distal end of said main body.

5. Wheelchair according to claim 3, wherein the hand actuator (501,504) comprises a disc portion (521,524) extending radially relative to said main axis, said manipulation portion (52) being located at a peripheral part of said disc portion.

6. Wheelchair according to any one of claims 1 to 5, wherein said hand actuator (50, 501, 502, 503, 504, 50s) is configured to take at least one active configuration in which it actuates said braking system (30), and a rest configuration in which it does not actuate the braking system.

7. Wheelchair according to claim 6, wherein said hand actuator (50, 501, 502, 503, 504, 50s) is configured to remain stationary relative to the frame (12) of the chair (10) when maintained in the rest configuration.

8. Wheelchair according to claim 6 or 7, wherein said hand actuator (50,501,502,503,504) is configured to move from the rest configuration to the active configuration by pivoting about a pivot axis (Y).

9. Wheelchair according to claim 8, wherein said pivot axis (Y) is parallel to said main axis (X), preferably coincident with said main axis.

10. A wheelchair according to any one of claims 6 to 8, wherein said hand actuator (50s) is configured to transition from the rest configuration to the active configuration by tilting towards the wheel (24).

11. Wheelchair according to any one of claims 6 to 10, wherein the braking system (30) further has a parking configuration in which it blocks the rotation of the wheel (24), the hand actuator (50,501,502,503,504) being configured to further assume a parking configuration in which it brings the braking system in the parking configuration, said hand actuator being fixed relative to the frame (12) of the chair when it is in said parking configuration.

12. Chair according to claim 11, wherein, starting from the rest configuration, said hand actuator (50) is configured to be brought into the active configuration by moving said hand actuator in a first direction, for example by pivoting in a first direction of rotation, and to be brought into the parking configuration by moving said hand actuator in a second direction, for example by pivoting in a second direction of rotation, opposite to the first direction, beyond a hard point.

13. Wheelchair according to any one of claims 1 to 12, wherein said first (38,138) and second (34,134) braking portions are located inside a cylindrical volume (V) defined by an inner radius (R) of the handrail (28) and extending along said main axis (X).

14. A wheelchair according to any one of claims 1 to 13, wherein said wheel (24) comprises a hub (26), said first (38,138) and second (34,134) braking portions extending within said hub.

15. A wheelchair according to any one of claims 1 to 14, wherein, when actuated, said braking system (30,130) is configured to bring the second braking portion (34,134) into contact with the first braking portion (38,138) and / or to bring the first braking portion (38,138) into contact with the second braking portion (34,134) so ​​as to generate friction between said first and second braking portions, whereby rotation of the wheel (24) relative to the main shaft (22) is braked.

16. Wheelchair according to claims 14 and 15, wherein the first braking portion (38) is fixed relative to the hub, the braking system (30) comprising a cam (32) cooperating with the hand actuator (50, 501, 502, 503, 504, 50s) and pivotally mounted by relative to the main shaft (22), said cam having a variable profile considered according to its circumference, said second braking portion (34) being located at the periphery of said cam, said cam being configured to pivot around the main axis when the braking system is actuated, so that said cam pushes said second braking portion radially against said first braking portion.

17. A wheelchair according to any one of claims 1 to 16, wherein said second braking portion (34,134) is a portion of the frame (12) of the wheelchair or a portion of the wheel system (20).

18. Wheelchair according to claim 17, wherein said wheel system (20) comprises said second braking portion (34,134), the wheel system (20) further comprising a locking part (60) configured to cooperate with a portion of the frame (12) of the chair, to block the rotation of the second braking portion relative to the frame in at least one direction of rotation.

19. Wheelchair according to claim 18, wherein said second braking portion (34,134) is integral with the main shaft (22), said locking part (60) being configured to block the rotation of the main shaft relative to the frame of the chair in at least one direction of rotation.

20. Wheelchair according to any one of claims 1 to 19, wherein said first (38,138) and second (34,134) braking portions are axially fixed along said main axis (X).