WO2025061342A1

WO2025061342A1 - Wheelchair advancer

Info

Publication number: WO2025061342A1
Application number: PCT/EP2024/070597
Authority: WO
Inventors: Lucy Bennett; Job SESINK; Mees VANDERBROECK; Bram STERKE
Original assignee: Ziggy Mobility BV
Current assignee: Ziggy Mobility BV
Priority date: 2023-09-18
Filing date: 2024-07-19
Publication date: 2025-03-27
Anticipated expiration: 2026-03-18
Also published as: NL1044687B1

Abstract

The invention relates to a wheelchair advancer, having a structure, said structure comprising: a wheelchair connector, and at least one handle for receiving an advancing force exertable by an attendant, wherein the handle consists of or comprises a steering device, which steering device is coupled to or couplable to a steerable wheel, wherein the steerable wheel is arranged to bear a significant part of the load the wheelchair is bearing when in use, when the wheelchair advancer is connected to the wheelchair.

Description

Title: Wheelchair advancer

The invention relates to a wheelchair advancer. More specifically, the invention relates to an accessory, mountable on a wheelchair, where an attendant, pushing the wheelchair, and the user of the wheelchair can move side by side during its use.

The advantage for being side by side is the convenience of communication and feeling of social connection between the attendant and the user which, in conventional wheelchairs, is rather awkward. With conventional wheelchairs, the attendant is typically behind the user, pushing the wheelchair from a position behind the back of the user.

In the art, some solutions have been proposed to overcome or alleviate this problem.

The Chinese patent CN104644350A discloses a push bar for sideways pushing a wheelchair. Here, the push bar is a lateral bar extending from the side of the wheelchair, such that the attendant and user can be side by side during its use. However, this push bar introduces some unbalanced moments such that steering the wheelchair becomes virtually impossible. Especially since most wheelchairs are equipped with a set of castor wheels, this push bar assembly will not properly function.

Although from an earlier date, the American patent US5141242A aims to solve the issue of the introduction of an unbalanced moment by means of a side push bar accessory with brakes, operable from the push bar, on the wheels of the actual wheelchair. By applying the left hand side and/or the right hand side brake, the introduction of the unbalanced moment can be compensated. In order to compensate for the unbalanced moment, the attendant needs to continuously apply some braking force to the wheel most proximal to him or her, such that the unbalanced moment is sufficiently counteracted. This means that the attendant needs to constantly exert additional pushing and breaking forces, rendering the use of this push bar inconvenient and strenuous.

The US patent US4415177 discloses a rather creative alternative to the problem where the user of the wheelchair is pushed backwards. Thus, the social awkwardness of traditional wheelchairs is indeed alleviated, yet, by pushing the user backward another awkwardness is simultaneously being introduced. Many people dislike being moved backward, unable to see where they are going. Therefore, this solution is still suboptimal.

Accordingly, it is an object of the invention to mitigate or solve the above described and/or other problems of wheelchairs in the art, while maintaining and/or improving the advantages thereof.

More specifically, the object of the invention can be seen in providing an easy to operate wheelchair, wherein the attendant can easily and directly communicate and interact with the user of the wheelchair, while the attendant can advance the wheelchair with a minimal amount of effort.

These and/or other objects are reached by a wheelchair advancer, having a structure, said structure comprising: a wheelchair connector, and at least one handle for receiving an advancing force exertable by an attendant, wherein the handle consists of or comprises a steering device, which steering device is coupled to or couplable to a steerable wheel, wherein the steerable wheel is arranged to bear a significant part of the load the wheelchair is bearing when in use, when the wheelchair advancer is connected to the wheelchair.

By this arrangement, the wheelchair can be easily and elegantly moved and steered, where compensation for any unbalanced moments is easily applied by the attendant. Since the steerable wheel is bearing a significant part of the load, it is having grip and is less prone to slipping, such that the unbalanced moment introduced by the advancing force exerted by the attendant on the handle is compensated for or balanced by the forces the steerable wheel exerts on the ground in combination with the forces exerted on the ground by the rear wheel or wheels of the wheelchair.

The significant part of the load is at least 8% of the load the wheelchair is bearing when in use.

It appears that when the load on the steerable wheel is below 8% of the load the wheelchair is bearing when in use, the grip between the steered wheel and the ground may become too low to compensate for or to balance the unbalanced moment. Preferably, the load the steerable wheel is bearing is higher in order to have sufficient grip to steer the wheelchair, and in order to reduce any slipping action between the steerable wheel and the ground.

The wheelchair advancer can be configured such that in use, a user and an attendant are positioned side by side. The side by side position of user and attendant improves communication and the feeling of social connection. Most likely the social connection and improved communication may aid in the wellbeing of the user, which may be beneficial to their health and/or recovery.

The handle of the advancer can, in use, be both positioned and extending laterally from the wheelchair, which it is connected to. Thus the attendant can position him- or herself next to the user of the wheelchair.

The steerable wheel can be part of the advancer or the steerable wheel can be part of the wheelchair. Thus the advancer can be an accessory that is either a single add on, where clamping or mounting the advancer alone is sufficient to use it or the advancer is equipped with a transmission, which allows for the steering action to be exerted on a wheel of the wheelchair.

Thus, various models and designs of wheelchairs can be equipped with the advancer, rendering it a flexible solution for as many different types of wheelchairs as possible. Here the steerable wheel can even be an existing wheel of the wheelchair or an additional wheel, mountable to the wheelchair. Again, these variants are allowing for more flexibility of using the invention with a wide variety of wheelchairs.

The location of the steerable wheel can be any other than the centre of rotation of the wheelchair the advancer is attached to. This is needed for the steerable wheel to exert a steering force to the wheelchair.

Additional castor or non-castor wheels may be added to the wheelchair to increase the stability of the wheelchair when the advancer is mounted thereto. Such additional wheels may also balance and/or share the loading on the wheelchair frame. This may make the forces on the wheelchair frame more favourable. In order to mount the advancer, it can comprise two mounting brackets, clamps or other means of attachments configured to be mountable to a frame of a wheelchair at two distinct locations of said frame.

Since the advancing force exerted by an attendant can introduce a moment, the use of two mounting brackets can make a connection that is more sturdy and less prone to bending due to the exerted moment.

In the case the advancer comprises a separate steerable wheel, the steerable wheel can comprise of its own mounting bracket, such that the advancer comprises at least two mountable parts: at least one comprising the handle and one comprising the wheel. This may be necessary for some models or types of wheelchairs, where a single part advancer is somehow difficult to be mounted thereto.

In an embodiment, the at least one handle and the steerable wheel are part of a steering assembly, wherein the wheelchair advancer comprises a lifting device configured to move the steerable wheel between a deployed position, in which the steerable wheel is configured to extend below a wheel supporting plane of the wheelchair, and a standby position, in which the steerable wheel is configured to be arranged above the wheel supporting plane of the wheelchair.

According to an aspect of the invention there is provided a wheelchair advancer, comprising: a wheelchair connector configured to be fixed on a wheelchair, and a steering assembly, the steering assembly comprising: at least one handle, and a steerable wheel operatively connected to the at least one handle, wherein the handle is configured to receive an advancing force and/or to receive steering inputs to steer the steerable wheel (6), and wherein the wheelchair advancer comprises a lifting device configured to move the steerable wheel between a deployed position, in which the steerable wheel is configured to extend below a wheel supporting plane of the wheelchair, and a standby position, in which the steerable wheel is configured to be arranged above the wheel supporting plane of the wheelchair.

The handle is configured to receive an advancing force and/or to receive steering inputs to steer the steerable wheel. An attendant may exert this force to the handle to advance the wheelchair in a forwards or backwards direction of the wheelchair. The attendant may steer by giving steering inputs to the handle when advancing to turn the wheelchair to the left and to the right.

The wheel supporting plane is defined as a plane tangential to the bottom of the wheels of the wheelchair on its own when supported on a horizontal surface and without additional support of the steerable wheel.

With the lifting device an attendant may transfer the load between a front wheel, e.g. castor wheel, of the wheelchair located on the lateral side on which the steering assembly is mounted and the steerable wheel of the steering assembly. When the load on the wheelchair is fully carried by the wheels of the wheelchair, the steerable wheel is above the supporting plane of the wheelchair and thus in a standby position. With the lifting device, the steerable wheel may be extended below the supporting plane i.e. arranged in the deployed position. This transfers the load from at least one of the front wheels of the wheelchair to the steerable wheel, since the at least one of the front wheels is/are lifted with respect to the steerable wheel.

In an embodiment wherein only one of the front wheels is lifted, the frame of the wheelchair may deform, due to a flexibility of the frame, such that the wheelchair is supported, with the steerable wheel in the deployed position, by the steerable wheel and the other wheels of the wheelchair. The lifted front wheel is now lifted above a plane defined by the other wheels of the wheelchair and the steerable wheel.

In an embodiment wherein both front wheels are lifted, for example when the steerable wheel is positioned between the two front wheels, and the load on the front wheels is transferred to the steerable wheel in the deployed position, the wheelchair is supported on the back wheels of the wheelchair and the steerable wheel.

Conventionally, the front wheels of a wheelchair are castor wheels. The castor wheel like mechanism has several inherent shortcomings. For example, castor wheels have an initial orientation that must be overcome. The castor wheels must thus first rotate from their previous rolling direction into a new, desired rolling direction which may lead to unpredictable swivelling. Furthermore, castor wheels cannot be controlled easily when powered.

When the castor front wheel would still carry a substantial part of the load when steering the steerable wheel of the wheelchair assembly, this may induce additional friction forces when the castor front wheel is in a different direction then the rolling direction of the steerable wheel and might lead to unpredictable swivelling. It is therefore an advantage of the present embodiment that the load is transferred from the front wheel to the steerable wheel of the steering assembly, since it increases steerability and controllability of the wheelchair.

The lifting device may also be used to ‘lower’ the wheelchair from the deployed position to the standby position by transferring the weight from the steering assembly to at least one of the front wheels, for example to the front wheel of the wheelchair located on the lateral side on which the steering assembly is mounted, or to both front wheels if the steerable wheel is arranged between the two front wheels.

Since the load is carried by the wheelchair when the steerable wheel is in the standby position, this makes it easier for an attendant to mount and demount the steering assembly on the wheelchair connector in the standby position. After the steering assembly is mounted on the wheelchair connector and the steerable wheel is in the standby position, an attendant may lower the steerable wheel to the deployed position, therewith transferring part of the load of the wheelchair from at least one of the front wheels of the wheelchair to the steerable wheel. Both lifting and lowering with the lifting device by an attendant may be carried out with a user sitting in the wheelchair or without a user sitting in the wheelchair.

In an embodiment, the lifting device of the wheelchair advancer comprises an axle connected to the steering assembly to allow rotation of the steering assembly to move the steerable wheel between the deployed position and the standby position. The axle may be connected to the steering assembly between the handle and the steerable wheel. An attendant may use the handle to rotate the steering assembly around the axis of the axle.

In this embodiment, tilting of the steering assembly around the axle may be used to rotate the steering assembly between the deployed position and the standby position.

The handle may be arranged at a sufficient distance from the axis of rotation such that the steering assembly acts as a lever and allows an attendant to easily lift the steerable wheel from the standby position to the deployed position and lower the steerable wheel from the deployed position to the standby position by exerting a corresponding force on the handle.

Other embodiments of the lifting device may for example employ a pump mechanism or a lifting screw mechanism to lift and lower the steerable wheel between the deployed and standby position.

In an embodiment, the lifting device comprises a lifting locking device configured to releasably lock the position of the steerable wheel in a deployed position and/or in a standby position. The lifting locking device may retain the steerable wheel in the deployed position by preventing rotation of the axle of the lifting device. The steerable wheel may be locked manually or may automatically be locked when moving the steerable wheel from the standby position to the deployed position or vice versa. The steerable wheel may be unlocked manually to move the steerable wheel back between the deployed position and the standby position.

In an embodiment wherein a rotatable steering assembly comprises the steerable wheel and the handle, the lifting locking device may for example comprise a pin arranged on one of the rotatable steering assembly and a frame part of the wheelchair advancer that remains in a fixed position with respect to the wheelchair and a slot in the other of the rotatable steering assembly and a frame part of the wheelchair advancer that remains in a fixed position with respect to the wheelchair. To lock the position of the rotatable steering assembly, and therewith the steerable wheel, in the deployed position the pin may be placed in the slot, and the steerable wheel may be released when the pin is taken out of the slot. The pin may be biased in the locking position, i.e. the position in which the pin extends into the slot. At a suitable location of the other of the rotatable steering assembly and a frame part of the wheelchair advancer that remains in a fixed position with respect to the wheelchair, a second slot may be provided to lock the position of the rotatable steering assembly, and therewith the steerable wheel, in the standby position.

In an embodiment, the at least one handle and the steerable wheel are part of a steering assembly, wherein the steering assembly is configured to be detachably mounted to the wheelchair connector and wherein the steering assembly is arranged on a lateral side of the wheelchair when mounted to the wheelchair connector.

According to another aspect of the invention there is provided a wheelchair advancer, comprising: a wheelchair connector configured to be fixed on a wheelchair, and a steering assembly, the steering assembly comprising: at least one handle, and a steerable wheel operatively connected to the at least one handle, wherein the handle is configured to receive an advancing force and/or to receive steering inputs to steer the steerable wheel, and wherein the steering assembly is configured to be detachably mounted to the wheelchair connector and wherein at least the at least one handle of the steering assembly is arranged on a lateral side of the wheelchair when mounted to the wheelchair connector.

The steering assembly is configured to be detachably mounted to the wheelchair connector on a lateral side of the wheelchair with respect to a forwards direction of the wheelchair.

The steering assembly may extend so far on a lateral side of the wheelchair that an attendant may position him/herself behind the handle of the steering assembly with respect to the forward direction of the wheelchair next to a user seated in the wheelchair to advance the wheelchair with the wheelchair advancer. As such, the attendant will be at a comfortable distance on the lateral side of the wheelchair for standing, walking and communicating with the user and for pushing or pulling the handle from behind to move the wheelchair in a forwards or backwards direction respectively. Furthermore, the height of the steering assembly may be configured to be adjusted to the height of an attendant. Advantageously, the wheelchair advancer may be of an ergonomic design for the attendant that allows an attendant to advance and steer the wheelchair efficiently and comfortably.

The steering assembly may optionally also be arranged in a stowed position on a lateral side of the wheelchair when mounted to the wheelchair connector. In the stowed position, the steering assembly is arranged such that it does not protrude laterally with respect to a forward position of the wheelchair from the wheelchair. This improves manoeuvrability in small spaces when there is not sufficient space for an attendant to be side-by-side to a user. The stowed position may also be used when parking the wheelchair, when it is not desired to have the steering assembly detached from the wheelchair.

For convenience the wheelchair connector only needs to be fixed to a wheelchair once and can be left on the wheelchair. The wheelchair may be advanced in a conventional manner by a user sitting in the wheelchair or by an attendant walking behind the wheelchair with the wheelchair connector fixed to the wheelchair and the steering assembly detached. To use the wheelchair advancer, the steering assembly may be mounted to the wheelchair connector such that an attendant may be positioned next to the user in the wheelchair. It may be a benefit of this embodiment of the wheelchair advancer that the steering assembly may be easily dismounted from the wheelchair connector in situations where this is preferable, for example when manoeuvring through narrow spaces, such as doorways and elevators. Furthermore, the steering assembly may be stored separately from the wheelchair and may be easily mounted in situations where an attendant is available and there is a sufficient amount of space to walk next to the wheelchair. The wheelchair connector may be installed by fixing it to a wheelchair, but may be released from the wheelchair for example to use the wheelchair connector on another wheelchair. It is also a possibility to have multiple wheelchairs with a fixed wheelchair connector that share a steering assembly. Furthermore, it is possible to have various embodiments of the wheelchair connector that may be fixed to wheelchairs that have different frame designs having an identical mounting arrangement for a steering assembly.

In an alternative embodiment of the wheelchair advancer, the wheelchair advancer may be fixed to the wheelchair connector. In this embodiment, the steering assembly may also be arranged on a lateral side of the wheelchair when the wheelchair connector with wheelchair advancer is mounted on the wheelchair.

In an embodiment, a rod and sleeve connection is provided to mount the steering assembly on the wheelchair connector. One of the wheelchair connector and the steering assembly comprises a mounting rod and the other of the wheelchair connector and the steering assembly comprises a sleeve. The cross section of the mounting rod has a non-round outer cross section and the sleeve has a mating non-round inner cross section to be placed on the mounting rod in a form fit manner. The non-round form fit cross sections ensure that the steering assembly cannot tilt with respect to the wheelchair connector around an axis along the length of the mounting rod and sleeve combination.

The non-round form fit inner and outer cross sections may be, but are not limited to a square, rectangular, hexagonal or star shape. The sleeve may have a closed inner cross-section, but may also have other non-round inner cross-sectional shapes that form fit the mounting rod. For example, when the mounting rod has a square cross-section, the sleeve may have a U-shaped cross-section. The sleeve may be placed on the mounting rod in a form fit manner in different orientations with respect to the mounting rod.

In an embodiment, the sleeve can be placed in a form fit manner on the mounting rod in a first orientation with respect to the mounting rod, wherein the steering assembly is arranged for advancing of the wheelchair. In this arrangement the steering assembly laterally extends on a lateral side of the wheelchair. The steerable wheel may be in a standby or deployed position.

In an embodiment, the sleeve can be placed in a form fit manner on the mounting rod in a second orientation with respect to the mounting rod, wherein the steering assembly is mounted in a stowed position. In the stowed position the steering assembly is arranged substantially above or below the mounting rod and sleeve combination on the lateral side of the wheelchair such that it does not protrude laterally as much as in the deployed and standby positions.

In an embodiment, the wheelchair connector comprises a supporting rod and at least two clamps configured to clamp the supporting rod on opposing sides of the frame of a wheelchair that fix the wheelchair connector to the wheelchair.

A conventional wheelchair frame comprises supporting rods or beams on both sides of the wheelchair that are substantially parallel to the forward direction of the wheelchair. The two clamps may clamp the supporting rod of the wheelchair connector to the supporting rods or beams on the opposing sides of the wheelchair. In this arrangement, the supporting rod of the wheelchair connector may be in a substantially horizontal orientation perpendicular to a forward direction of the wheelchair. Advantageously, this provides additional structural support to the wheelchair and wheelchair advancer combination, to absorb and/or transfer torques resulting from forces applied to the steering assembly arranged on the lateral side of the wheelchair.

The supporting rod of the wheelchair connector may span the width of the wheelchair frame or may protrude slightly outside of the wheelchair frame. The supporting rod may be a straight rod, but may also be of another shape for example but not limited to an L-shape, U-shape, arc shape or bow shape. The supporting rod may have a part that is protruding on a lateral side of the wheelchair frame in a substantially downward direction with respect to the wheelchair frame. This lowers the position of the connection between the wheelchair connector and the steering assembly altering the forces and moments acting on the wheelchair when operating the steering assembly which increases ease of operation of the wheelchair advancer by an attendant.

In an embodiment, the mounting rod or sleeve of the wheelchair connector is connected to an end of the supporting rod. This may be a rigid connection. The mounting rod or sleeve is arranged laterally on the outside of the lateral side of the wheelchair frame whereon the wheelchair connector is mounted and is extending in a forward direction of the wheelchair with respect to the supporting rod.

The rod or sleeve on which the wheelchair assembly is mounted may be arranged on the left side or on the right side of the wheelchair such that the steering assembly may be mounted on the preferred side. A mounting rod or sleeve may also be provided on both the left and right side of the wheelchair connector, such that a steering assembly may be attached on either side. By arranging the steering assembly more towards the front relative to the wheelchair frame with respect to the forward direction of the wheelchair, beneficially there is more space for the attendant to be positioned side-by-side to the user sitting in the wheelchair, when operating the steering assembly with the handle. Furthermore, the steerable wheel of the wheelchair assembly is positioned more towards the front with respect to the centre of rotation of the wheelchair in this arrangement, increasing controllability and steerability when an attendant is advancing the wheelchair.

In an embodiment, the wheelchair advancer comprises a steering assembly locking device configured to releasably lock the position and orientation of the sleeve with respect to the mounting rod. The locking mechanism of the locking device retains the position and orientation of the sleeve with respect to the mounting rod and may for example but not limited to be of a pin or latch type.

The sleeve may be locked to the mounting rod when the sleeve is placed on the mounting rod in a form fit manner in different orientations with respect to the mounting rod. For example, the steering assembly may be mounted and locked in the first orientation for advancing the wheelchair and/or may be mounted and locked in the second orientation for stowing the steering assembly.

When mounting the steering assembly on the wheelchair connector the locking mechanism may automatically be locked when placing the sleeve on the mounting rod or be manually locked, for example by using a pin biased in the locked position. To unmount the steering assembly from the wheelchair connector the steering assembly locking device may be unlocked manually.

The invention also relates to an assembly of a wheelchair and a wheelchair advancer as described herein.

Finally, the invention relates to a method of using a wheelchair advancer comprising the following steps: A) providing a wheelchair; B) providing a wheelchair advancer as described herein; C) mounting the wheelchair advancer to the wheelchair; D) using the wheelchair by having a user sit in the wheelchair and an attendant pushing the wheelchair by exerting an advancing force to the handle and a steering action to the handle or the steering device. Thus, the advantages of a side by side arrangement of attendant and user can be obtained, while unbalanced moments can be reduced or eliminated, such that the attendant can easily and comfortably advance the wheelchair, without having to exert additional forces to compensate for any of these moments.

In order to further elucidate the invention, exemplary embodiments will be described with reference to the figures. In the figures:

Figure 1 A depicts a first schematic front view of a wheelchair and a wheelchair advancer according to a first embodiment of the invention;

Figure 1 B depicts a first schematic side view of a wheelchair and a wheelchair advancer according to a first embodiment of the invention as depicted in figure 1A;

Figure 2A depicts a first schematic front view of a wheelchair and a wheelchair advancer according to a second embodiment of the invention;

Figure 2B depicts a first schematic side view of a wheelchair and a wheelchair advancer according to a second embodiment of the invention, in accordance with figure 2A;

Figure 3A depicts a first schematic front view of a wheelchair and a wheelchair advancer according to a further embodiment of the invention;

Figure 3B depicts a first schematic side view of a wheelchair and a wheelchair advancer according to the embodiment of the invention according to figure 3A;

Figure 4 depicts a second schematic perspective view of a wheelchair and a wheelchair advancer according to an embodiment of the invention;

Figure 5 depicts a schematic view of a wheelchair and wheelchair advancer according to an embodiment of the invention, wherein the steering assembly is unmounted from the wheelchair connector.

Figure 6A-6D depict schematic side view of a wheelchair and wheelchair advancer according to an embodiment of the invention, wherein the lifting mechanism of the lifting device is demonstrated.

Figure 7 depicts a schematic perspective view of a wheelchair and a wheelchair advancer according to an embodiment of the invention, wherein the steering assembly is in a stowed position. The figures represent specific exemplary embodiments of the inventions and should not be considered limiting the invention in any way or form. Throughout the description and the figures the same or corresponding reference numerals are used for the same or corresponding elements.

The expressions “steerable” and “steerable wheel” used herein are to be understood as, though not to be considered limited to, a coupling between two rotatable parts, e.g. between the wheel rotatably connected to the structure and the handle rotatably connected to the structure, wherein the axis of rotation is substantially upright, such that the motion of rotation is acting in a substantially level plane. In this manner, the angle of rotation of the coupling may be considered as, but not limited to, being controllable or configurable by the user.

The expression “wheelchair” used herein is to be understood as, though not to be considered limited to, a transportation device with a seat or seat-like structure in which a user can sit, which wheelchair is to be pushed forward by an attendant. Typically, these wheelchairs comprise two relatively large wheels on the rear side of the wheelchair and two castor wheels on the front side of the wheelchair.

The expression “castor wheel” used herein is to be understood as, though not to be considered limited to, a wheel mounted in a bracket, the wheel being rotatable around a first substantially level axis mounted in said bracket, wherein the bracket itself is rotatably, around a second, substantially upright axis, mountable and wherein the first and second axes are positioned at a distance, such that the wheel when mounted is able to swivel and follows the direction it is moved in.

The expression “load” used herein is to be understood as, though not to be considered limited to, the load exerted due to gravity by the mass of the user and/or the wheelchair.

The expression “significant part of the load” used herein is to be understood as, though not to be considered limited to 8% or more of the load as described herein above.

The expression “user” or “wheelchair user” used herein is to be understood as, though not to be considered limited to, a person or an animal that is seated or sitting in the chair portion of the wheelchair.

The expression “attendant” used herein is to be understood as, though not to be considered limited to, the person who is advancing the wheelchair, so this is the person exerting the force of motion to the wheelchair.

In figures 1A and 1 B, a wheelchair advancer 1 is schematically depicted, connected to wheelchair 2. The advancer is equipped with a handle bar 3, which is mounted on an axis of rotation 4, which is rotatably connected in the head tube 5 of the advancer 1 . The head tube 5 is connected to the frame 13 of the wheelchair by means of connecting structure 8. The axis of rotation 4 extends through the head tube 5 and is connected to fork 7, in which the steerable wheel 6 is rotatably connected.

Wheelchair 2 in the figures 1A and 1 B is equipped with a chair 11 , to which a handle 12 is connected, which forms part of the wheelchair frame 13. An attendant can, during use, exert an advancing force to the handle, in order to advance the wheelchair. This is the conventional way a wheelchair 2 is operated. Now, since the wheelchair advancer 1 is connected to the wheelchair 2, the wheelchair can be advanced from a lateral side of the wheelchair as is described herein below.

The head tube 5 is connected to the frame 13 of the wheelchair 2 such, that the vertical load on wheel 15A is significantly reduced, this can result in slightly lifting the wheel 15A from the ground G. The wheel 15B can be still in contact with the ground G, or be lifted as well.

Here, the steerable wheel 6 is touching the ground G and bears an significant part of the load of the wheelchair 2. This load is the load induced by the weight of the wheelchair user and/or the wheelchair.

If now an attendant exerts an advancing force to the handle bar 3, the attendant can both advance and steer the wheelchair 2, with relatively low effort whilst walking/being next to the user of the wheelchair 2. In the embodiment as depicted in figures 1A and 1 B, the handle bar 3 and the steerable wheel 6 are directly coupled, by means of a fixed axis of rotation 4, i.e. the wheel 6 and the handle bar 3 turn in a 1 :1 ratio.

In figures 2A and 2B, the handle bar 3 is rotatably connected to head tube 5, which is connected to the frame 13 of the wheelchair 2 by means of connecting structure 8.

Alternatively, the handle bar 3 may be connectable in a non-rotatable manner directly or indirectly to the frame 13. In this way, the handle bar 3 comprises a steering device.

In this embodiment, the handle bar 3 operates either a castor wheel of the wheelchair 2 or an added steerable wheel, both indicated in figures 2A and 2B as reference number 6A. So while wheel 15B is still following the direction of the wheelchair, the wheel 6A is actually guiding the direction through the action exerted on the handle bar 3. So the steering action of an attendant exerted on handle bar 3 acts through transmission 9 to either a castor wheel of the wheelchair 2 or to an added steerable wheel, both indicated in figures 2A and 2B as reference number 6A. In this arrangement, the ratio of motion can be set. It can be a steering ratio of 1 :1 yet any other ratio can be applied in a similar fashion. So the steering can have a lower ratio, such that one turn of the handle bar 3 coincides with e.g. half a turn of the steerable wheel 6A.

Here, the transmission can be by means of Bowden cables, a chain, a belt, a linkage, a set of gears or by any other means, mechanically, electronically, or by means of fluid mechanic devices.

In figures 2A and 2B the wheel 6A can be a conventional castor wheel, being part of wheelchair 2, or an added steerable wheel.

In figures 3A and 3B the connection between the handle bar 3 and the steerable wheel 6 is coupled through a transmission 9. In the embodiment as depicted in figures 3A and 3B, the steerable wheel 6 is positioned at or close to the symmetry plane of the wheelchair. Here again the steerable wheel 6 is touching the ground G and bears an significant part of the load of the wheelchair 2. In this embodiment the load on both wheels 15A and 15B is reduced. This may result in the lifting of those castor wheels, as depicted in figures 3A and 3B. Since the steerable wheel 6 and the handle bar 3 are coupled through a transmission 9, the ratio of motion can be set. It can be a steering ratio of 1 :1 yet any other ratio can be applied in a similar fashion. So the steering can have a lower ratio, such that one turn of the handle bar coincides with e.g. half a turn of the steerable wheel 6.

Here, the transmission can be by means of Bowden cables, a chain, a belt, a linkage, a set of gears, or by any other means, mechanically, electronically, or by means of fluid mechanic devices.

It is preferred that the steerable wheel 6 or 6A is offset from the steering axle 4 or axis of rotation 10 advancing in the direction of motion of the wheelchair 2, while the wheels 15A and 15B are offset from the axes of rotation 17A and 17B in a direction opposite to the direction of motion of the wheelchair 2.

Preferably, the axis of rotation being the steering axle 4 in figure 1A and 1 B or 10 in the other figures, of the wheel 6 or 6A is inclined such that the connection with fork 7 is slightly more advanced in the direction of motion of the wheelchair 2 than the connection of the axis of rotation 4 or 10 to either the head tube 5 (as is depicted in figures 1A and 1 B) or the frame 13 (as is depicted in figures 2A, 2B and 3A and 3B).

The invention is to be understood but not to be limited to the exemplary embodiments shown in the figures and described in the specification. For instance the advancer can be a foldable assembly or comprise foldable parts. Herein, the structure and/or the bracket can be foldable, thus the transportability can be improved. Additionally, this would allow the wheelchair to pass through narrow passages and doorways when the advancer is mounted thereto. This would be an essential feature to allow for convenient use.

Preferably, the steerable wheel 6 or 6A has a coefficient of friction equal to or greater than 0.2 between itself and the ground G. This is to ensure that there is a sufficiently large friction force between the wheel 6 or 6A and the ground G to prevent slipping.

Alternatively, the advancer and the wheelchair can be an operable unit wherein the advancer is either fixedly connected to the wheelchair or integrated in the frame of the wheelchair as an adapted wheelchair with advancer.

The steering device of the wheelchair advancer can be a pair of handles, placed on mutual distal sides of a bar having its axis of rotation in between the handles. Thus the steering handle assembly resembles a handle bar of a bicycle. The steering device can be directly coupled to the steerable wheel, such that the steering device and the wheel are mounted to a rotation axle, such as a tube, which axle is rotatable around a substantially upright axis of rotation. Herewith, the steerable wheel can be suspended in e.g. a fork.

Alternatively, the steering device can be indirectly coupled to the steerable wheel, by means of a transmission 9, for example gears, Bowden cables, a belt, a linkage, a chain, or any other suitable way.

Alternatively, the steerable wheel 6 or 6A can be suspended from the advancer 1 or wheelchair frame 13 by a compliant connection, being a compression spring, a pneumatic spring or any other type of compliant member. This is to ensure the steerable wheel 6 or 6A bears a sufficient load to prevent slipping between the ground G and the wheel 6 or 6A when traversing uneven terrain. This may also improve user comfort.

In a further alternative, the steerable wheel can be power operated, for either the steering action and/or for the advancing action. The advancer can furthermore comprise an integrated bicycle, operated such that the attendant sits on said bicycle, while the wheelchair can be coupled as a sidecar.

The steerable wheel may be further equipped with a clutch and/or a brake. Thus, in specific instances, the wheelchair movement can be enhanced or impaired, as the specific situation may require.

Figures 4-7 depict an embodiment of a wheelchair advancer 1 and a wheelchair 2 comprising a wheelchair connector 18 fixed to the wheelchair 2 and a steering assembly 19. Figure 4 and Figure 5 show the wheelchair advancer with the steering assembly 19 respectively mounted and unmounted to the wheelchair connector 18.

The steering assembly 19 comprises a handle 3 and a steerable wheel 6 operatively connected to the handle 3. The handle 3 is configured to receive an advancing force and/or to receive steering inputs to steer the steerable wheel 6. By rotating the handle 3 around the steering axis 4 of the steering assembly 19 the steerable wheel 6 is turned.

The wheelchair connector 18 comprises a supporting rod 22 and two clamps 23A and 23B that clamp the supporting rod 22 on a left and right side of the frame 13 of the wheelchair 2. The wheelchair connector supporting rod 22 is of an L-shape, wherein a first part spans the wheelchair frame 13 horizontally and perpendicular to a forward direction FD of the wheelchair 2 and wherein a second part extends downward laterally on the left side of the wheelchair. This effectively lowers the position of the connection between the wheelchair connector 18 and the steering assembly 19.

The wheelchair connector 18 comprises a square mounting rod 20 that is rigidly connected to the L-shaped supporting rod 22 and extends in a direction parallel to a forward direction FD of the wheelchair 2 on the side of the wheelchair 2.

The wheelchair assembly 19 comprises a square sleeve 21 that is placed on the mounting rod 20 when the wheelchair assembly 19 is mounted to the wheelchair connector 18. The square sleeve may be placed on the mounting rod 20 in a first orientation with respect to the mounting rod 20 for advancing the wheelchair (Figure 4 and Figure 6) or in a second orientation for stowing (Figure 7). A steering assembly locking device 24 is provided to retain the position of the sleeve 21 of the wheelchair assembly 19 with respect to the mounting rod 20 of the wheelchair connector 18 when mounted. The steering assembly locking device 24 comprising a pin mounted on the steering assembly 19.

The steering assembly 19 comprises a lifting device 25 with an axle 26 to move the steerable wheel 6 between a deployed position and a standby position by rotation of the steering assembly 19 around an axis of rotation of the axle 26. The lifting device 25 comprises a lifting locking device 27 to lock the position of the steerable wheel 6 in the deployed or standby position. The lifting locking device 27 comprises a biased pin and a slot in which the pin may extend. Figures 6A-6D show a side view of the embodiment demonstrating movement between a standby position and a deployed position. A wheel supporting plane SP tangential to the bottom of the wheels 14A, 14B, 15A, 15B of the wheelchair 2 and a ground plane GP on which the wheelchair 2 and wheelchair advancer combination is supported are indicated for reference.

Figure 6A and Figure 6B depict the steerable wheel 6 in a standby position, wherein the steerable wheel 6 is above the supporting plane SP. Figure 6C depicts the steerable wheel 6 just before transferring the load between the left front wheel 15A of the wheelchair 2 and the steerable wheel 6. Figure 6D depicts the steerable wheel 6 in a deployed position, wherein the steerable wheel 6 extends below the wheel supporting plane SP of the wheelchair 2. In this case, the front wheel 15A of the wheelchair 2 is lifted off the ground. The other wheels (14A, 14B and 15B) of the wheelchair 2 remain supported on the ground plane GP as the wheelchair frame slightly deforms to support the load.

The steering assembly 19 is rotated in a rotation direction RD and acting as a lever by applying a force at the handle 3 around the axis of the lifting axle 26. By arranging the handle further away from the axle 26 the arm of the lever is increased such that the force on the handle 3 required for lifting is decreased. This makes it possible for an attendant to easily transfer the load between the front wheel 15A and the steerable wheel 6 even when a user is seated in the wheelchair 2. Similarly, it is beneficial to decrease the distance from the steerable wheel 6 to the axle 26, which is achieved by the downward extending vertical part of the L-shaped supporting rod 22 of the wheelchair connector 18.

Conventional wheelchairs are usually designed with front castor wheels that have a negative castor angle, because the advancing force is applied from behind the wheelchair on the handles 12 of the wheelchair and the castor wheels (15A, 15B) are thus passive and follow steering inputs on the back wheels (14A, 14B). When a wheel is steerable it is preferable that the steerable wheel has a positive castor angle, which improves straight-line stability at speed by producing a self-aligning torque on the steerable wheel and improves controllability and cornering performance.

In the deployed position (Figure 6D) the steering axle 4 of the steering assembly 19 is tilted backwards with respect to the steerable wheel 6 and with respect to the forward direction FD of the wheelchair 2. Because of this tilt, the steerable wheel 6 advantageously has a positive castor angle and pushing forces applied by an attendant to the handle 3 result in more efficient advancing of the wheelchair 2 and wheelchair advancer 1 combination.

The steerable wheel 6 may only be extended slightly below the wheel supporting plane SP such that the load of the lifted castor wheel 15A is transferred to the steerable wheel 6, but the wheelchair 2 remains in a substantially upright position that is still comfortable for a user seated in the wheelchair and does not increase stability risks.

Figure 7 depicts the embodiment with the steering assembly 19 mounted on the wheelchair connector 18 in a stowed orientation. The sleeve 21 is mounted on the mounting rod 20 in the second orientation such that the steering assembly 19 does not protrude laterally. The axle 26 of the lifting device 25 is therefore rotated such that steering axle 4 of the steering assembly 19 is substantially parallel to a forward direction FD of the wheelchair. This rotation angle of the axle 26 is similar to the rotation angle of the axle 26 when the steerable wheel is in a standby position and the sleeve 21 is mounted on the mounting rod 20 in the first orientation. Therefore, the lifting locking device 27 may be used to lock the rotation angle in the standby position for stowing. Furthermore, the steering assembly locking device 24 may be used to lock the position and orientation of the steering assembly 19 respect to the mounting rod 20 in the second orientation for stowing.

These and other modifications are considered to be variations that are part of the framework, the spirit and the scope of the invention outlined in the claims.

List of reference signs

1 . Advancer

2. Wheelchair

3. Handle bar

4. Steering axle

5. Headtube

6. Steerable wheel

6A. Steerable wheel

7. Fork

8. Connecting structure

9. Transmission

10. Axis of rotation

11 . Seat

12. Handle

13. Wheelchair frame

14A. Wheel

14B. Wheel

15A. Wheel

15B. Wheel

16A. Bracket

16B. Bracket

17A. Axis of rotation

17B. Axis of rotation

18. Wheelchair connector

19. Steering assembly

20. Mounting rod

21 . Sleeve

22. Supporting rod

23A. Clamp

23B. Clamp

24. Steering assembly locking device

25. Lifting device

26. Axle

27. Lifting locking device

SP. Supporting plane

GP. Ground plane

FD. Forward direction of the wheelchair

Claims

1 . A wheelchair advancer (1), having

- a structure (8), said structure (8) comprising:

- a wheelchair connector,

- and at least one handle (3) for receiving an advancing force exertable by an attendant, wherein the handle (3) consists of or comprises a steering device, which steering device is coupled to or couplable to a steerable wheel (6, 6A), characterised in that the steerable wheel (6, 6A) is arranged to bear a significant part of the load the wheelchair (2) is bearing when in use, when the wheelchair advancer (1) is connected to the wheelchair (2).

2. A wheelchair advancer (1) according to claim 1 , wherein the significant part of the load is at least 8% of the load the wheelchair (2) is bearing when in use.

3. The wheelchair advancer (1) according to claim 1 or 2 wherein the wheelchair advancer (1) is configured such that, in use, a user and an attendant are positioned side by side.

4. The wheelchair advancer (1) according to any of claims 1 to 3, wherein the handle (3) of the advancer (1) is in use positioned and extending laterally from the wheelchair (2), which it is connected to.

5. The wheelchair advancer (1) according to any preceding claims, wherein the steerable wheel (6) is part of the advancer (1) or the steerable wheel (6A) is part of the wheelchair.

6. The wheelchair advancer (1) according to claim 5, wherein the steerable wheel is an existing wheel (6A) of the wheelchair.

7. The wheelchair advancer (1) according to claim 5, wherein the steerable wheel (6) is an additional wheel, mountable to the wheelchair (2).

8. The wheelchair advancer (1) according to any of the preceding claims, wherein the advancer (1) comprises two mounting brackets configured to be mountable to a frame (13) of a wheelchair at two distinct locations of said frame (13).

9. The wheelchair advancer (1) according to claim 7, wherein the steerable wheel (6) comprises its own mounting bracket, such that the advancer (1) comprises at least two mountable parts; at least one comprising the handle (3) and one comprising the steerable wheel (6).

10. A wheelchair advancer (1), comprising: a wheelchair connector (18) configured to be fixed on a wheelchair (2), and a steering assembly (19), the steering assembly (19) comprising: at least one handle (3), and a steerable wheel (6) operatively connected to the at least one handle (3), wherein the handle (3) is configured to receive an advancing force and/or to receive steering inputs to steer the steerable wheel (6), and wherein the wheelchair advancer (1) comprises a lifting device (25) configured to move the steerable wheel (6) between a deployed position, in which the steerable wheel (6) is configured to extend below a wheel supporting plane of the wheelchair (2), and a standby position, in which the steerable wheel (6) is configured to be arranged above the wheel supporting plane of the wheelchair (2).

11 . The wheelchair advancer (1) according to any of the claims 1-9, wherein the at least one handle and the steerable wheel are part of a steering assembly, wherein the wheelchair advancer (1) comprises a lifting device (25) configured to move the steerable wheel (6) between a deployed position, in which the steerable wheel (6) is configured to extend below a wheel supporting plane of the wheelchair (2), and a standby position, in which the steerable wheel (6) is configured to be arranged above the wheel supporting plane of the wheelchair (2).

12. The wheelchair advancer (1) according to claim 10 or 11 , wherein the lifting device (25) comprises an axle (26) connected to the steering assembly (19) to allow rotating of the steering assembly (19) to move the steerable wheel (6) between the deployed position and the standby position.

13. The wheelchair advancer (1) according to any of the claims 10-12, wherein the lifting device (25) comprises a lifting locking device (27) configured to releasably lock the position of the steerable wheel (6) in a deployed position and/or a standby position.

14. The wheelchair advancer (1) according to any of the claims 10-13, wherein the steering assembly (19) is configured to be detachably mounted to the wheelchair connector (18), and wherein at least the at least one handle of the steering assembly (19) is arranged on a lateral side of the wheelchair (2) when mounted to the wheelchair connector.

15. The wheelchair advancer (1) according to claim 14, wherein one of the wheelchair connector (18) and the steering assembly (19) comprises a mounting rod (20) having a non-round outer cross section, and wherein the other of the wheelchair connector (18) and the steering assembly (19) comprises a sleeve (21) having a non-round inner cross section, wherein the inner and outer cross section are mating such that the sleeve (21) can be placed on the mounting rod (20) in a form fit manner to mount the steering assembly (19) on the wheelchair connector (18).

16. The wheelchair advancer (1) according to claim 15, wherein the sleeve can be placed on the mounting rod in a first orientation with respect to the mounting rod, wherein the steering assembly is arranged for advancing of the wheelchair.

17. The wheelchair advancer (1) according to claim 15 or 16, wherein the sleeve can be placed on the mounting rod in a second orientation with respect to the mounting rod, wherein the steering assembly is arranged in a stowed position.

18. The wheelchair advancer according to any of the claims 14-17, wherein the wheelchair connector (18) comprises a supporting rod (22) and at least two clamps (23A, 23B) configured to clamp the supporting rod (22) on opposing sides of the frame (13) of a wheelchair (2).

19. The wheelchair advancer (1) according to any of the claims 15-18, wherein the mounting rod (20) or sleeve (21) of the wheelchair connector is connected to a mounting end of the supporting rod (22), which mounting end is arranged laterally on the outside of a wheelchair (2) on which the wheelchair connector (18) is mounted and extends in a forward direction of the wheelchair (2) with respect to the supporting rod (22).

20. The wheelchair advancer (1) according to any of the claims 15-19, wherein the wheelchair advancer (1) comprises a steering assembly locking device (24) configured to releasably lock the position and/or orientation of the sleeve (21) with respect to the mounting rod (20).

21 . An assembly of a wheelchair (2) and a wheelchair advancer (1) according to any of the preceding claims.

22. A method of using a wheelchair advancer (1) comprising the following steps:

A) providing a wheelchair (2);

B) providing a wheelchair advancer (1) according to any of the claims 1 to 20;

C) mounting the wheelchair advancer (1) to the wheelchair (2);

D) using the wheelchair (2) by having a user sit in the wheelchair (2) and an attendant pushing the wheelchair (2) by exerting force to the handle (3) and a steering action to the handle (3) or the steering device.