Pushing arrangement for a wheelchair

Abstract

The present invention relates to a pushing arrangement, configured to be arranged on a manual wheelchair, wherein the pushing arrangement is configured to allow a pushing person to push the manual wheelchair in a pushing direction over a ground surface while the manual wheelchair is in a reverse orientation, with a person sitting in the manual wheelchair facing the pushing person, said pushing arrangement comprising an elongated handlebar comprising grips attached at each end of the handlebar; an elongated frame attachment bar, configured for attachment to the frame of the wheelchair; an elongated push bar, configured for attachment to the handlebar and the frame attachment bar; a coupling element, configured for engaging with an outer circumference of a section of the frame attachment bar, to couple the frame attachment bar with the push bar; wherein the frame attachment bar has an unround outer circumference, and the coupling element has a corresponding unround inner circumference to allow a form fitting connection in a plurality of orientations of the coupling element, and consequently also the push bar, relative to the frame attachment bar; and wherein the frame attachment bar is configured as a torsion axle.

Description

[0001] The present invention generally relates to the field of mobility devices, and more particularly to the field of manual wheelchair accessories and enhancements.

[0002] Conventional wheelchairs are typically designed to allow a pusher to propel or push the occupant of the wheelchair from behind. In this configuration, the pusher is positioned at the backside of the wheelchair, where the backrest is situated. This standard design incorporates two handles on the backside of the wheelchair, allowing the pusher to maneuver the wheelchair forward. Consequently, the occupant is oriented with their back to the pusher, and both the pusher's and the occupant's field of view is primarily directed in the same direction, being the direction in which the wheelchair is being pushed. This design is (the) standard for manual wheelchairs, which are commonly referred to as pushchairs or transport wheelchairs, intended for moving the occupant over distances, such as during a walk or outdoor activity.

[0003] However, an important disadvantage of this conventional arrangement is the lack of visual contact between the occupant and the pusher. With the occupant facing away from the pusher, both verbal and non-verbal communication are hindered, complicating interactions during the use of the wheelchair. This limitation can be particularly problematic in situations where the occupant needs to communicate frequently with the pusher, such as when navigating through crowded or complex environments. The inability to easily see or communicate with each other can lead to discomfort, misunderstanding, and a less enjoyable experience for both parties.

[0004] While there are existing solutions that address these communication challenges, these solutions still leave room for improvement. These solutions may not be universally compatible with the wide variety of wheelchair designs, differing in frame configuration, frame thickness, and width. Furthermore, these arrangements may be more complex in design, making them difficult to store, having a large bill of materials, and increasing cost of production due to a complex manufacturing process. The weight and bulkiness of these solutions may also detract from the overall usability and convenience.

[0005] It is therefore a goal of the present invention to provide a further improved pushing arrangement for manual wheelchairs that facilitates improved visual and communicative contact between the pusher and the occupant, which overcome the above-mentioned disadvantages of the prior art at least in part. The arrangement aims to be lightweight, simple in design, cost-effective in terms of production and materials, and universally compatible with various wheelchair designs, while also ensuring a robust and comfortable pushing experience across different terrains.

[0006] This objective is achieved by means of a pushing arrangement, configured to be arranged on a manual wheelchair, wherein the pushing arrangement is configured to allow a pushing person to push the manual wheelchair in a pushing direction over a ground surface while the manual wheelchair is in a reverse orientation, with a person sitting in the manual wheelchair facing the pushing person, said pushing arrangement comprising: an elongated handlebar comprising grips attached at each end of the handlebar; an elongated frame attachment bar, configured for attachment to the frame of the wheelchair; an elongated push bar, configured for attachment to the handlebar and the frame attachment bar; a coupling element, configured for engaging with an outer circumference of a section of the frame attachment bar, to couple the frame attachment bar with the push bar; wherein the frame attachment bar has an unround outer circumference, and the coupling element has a corresponding unround inner circumference to allow a form fitting connection in a plurality of orientations of the coupling element, and consequently also the push bar, relative to the frame attachment bar; and wherein the frame attachment bar is configured as a torsion axle.

[0007] The pushing arrangement according to an aspect of the present invention allows a conventional manual wheelchair to be pushed in a user-friendly way from the front by the pusher. The front of the manual wheelchair refers to the side of the wheelchair facing away from the rear of the manual wheelchair. The front of the wheelchair is configured to be equipped with footrests for supporting the feet of the occupant. Because the manual wheelchair is pushed from the front, the manual wheelchair is propelled in reverse orientation, where the field of view of the pusher is essentially oriented towards the pushing direction and the field of view of the occupant is essentially oriented in the direction opposite to the pushing direction. Because the field of view of the occupant and of the pusher are essentially directed towards each other, the pushing arrangement according to the present invention enables full-fledged communication between the occupant and the pusher, where the occupant and the pusher can communicate verbally as well as non-verbally in a decent way.

[0008] The pushing arrangement is especially beneficial when the occupant suffers from a form of dementia or has an intellectual disability. For this group of people, the verbal communication can be so limited, that pushing the manual wheelchair in the conventional way can almost completely exclude the possibility of communication. In addition, the use of the pushing arrangement also facilitates verbal communication between the occupant and the pusher, since the pusher and the occupant talk towards each other, instead of away from each other, as is the case for the conventional way of pushing the manual wheelchair. Especially when the occupant and / or the pusher is / are hearing impaired and when there is a lot of ambient noise, the pushing arrangement according to the present invention is particularly beneficial.

[0009] The pushing arrangement according to the present invention does not exclude the use of the original handles at the rear of the manual wheelchair. The original handles can be used if desired, for example when manoeuvring the manual wheelchair on a rise of the sidewalk, without having to remove or adjust the pushing arrangement. The pushing arrangement can also be used to pull the manual wheelchair in certain situations. Another advantage of the present invention is that the handles of the pushing arrangement may be positioned further away from the centre of the manual wheelchair than the original handles located at the rear of the manual wheelchair. This favours the leverage, making it easier for the pusher to turn the manual wheelchair.

[0010] An additional advantage of the present invention is that in the operating condition of the pushing arrangement, in case the manual wheelchair is equipped with small swivel wheels at the front and large wheels at the rear, it is easier to manoeuvrer the manual wheelchair over rough terrain, such as a ground surface consisting of cobblestones or gravel, since the large wheels are located in front of the small swivel wheels, as seen from the pushing direction.

[0011] Another advantage of the pushing arrangement according to the present invention, is that the pushing arrangement is universal and therefore can easily be retrofitted on the manual wheelchair and is suitable for almost all manual wheelchairs. The fixation parts of the two coupling pieces are mounted on a frame tube section on a left font side and on a right front side of the manual wheelchair.

[0012] As indicted, the pushing arrangement is configured to be arranged on a manual wheelchair. A pushing arrangement may be understood as a set of components designed to facilitate the manual propulsion of a wheelchair by a person pushing it. A manual wheelchair refers to a wheelchair that is propelled by a manual force, typically by a person pushing it, and not by any motorized means. The pushing arrangement is designed to allow a pushing person to push the manual wheelchair in a pushing direction over a ground surface while the wheelchair is in a reverse orientation, meaning the person sitting in the wheelchair faces the pushing person.

[0013] The arrangement comprises an elongated handlebar with grips attached at each end of the handlebar, preferably at the distal ends. A handlebar, in this context, is a bar used to steer or push a vehicle or apparatus, often with grips to improve the handling and control by the user. The elongated shape of the handlebar allows it to span across the width of the wheelchair, providing a stable and ergonomic interface for the pushing person. The inclusion of grips at each end of the handlebar enhances the control and comfort for the pusher, allowing for a secure hold, which can reduce strain on the hands and wrists during use. The handlebar provides improved maneuverability of the wheelchair, especially over uneven or rough surfaces, as the pusher can maintain a consistent and comfortable grip.

[0014] The arrangement further comprises an elongated frame attachment bar, configured for attachment to the frame of the wheelchair. The frame attachment bar is preferably attachable to the frame of the wheelchair at distal ends of the bar. A frame attachment bar can be understood as a structural component that connects the handlebar to the frame of the wheelchair, ensuring that the pushing forces are effectively transmitted to the wheelchair. The elongated design allows for versatile placement along the frame of the wheelchair, accommodating various wheelchair designs and dimensions. The configuration for attachment ensures that the bar can be securely fastened to the frame, which contributes to the overall stability of the pushing arrangement. The bar provides a reliable connection between the handlebar and the wheelchair, facilitating efficient transmission of pushing forces while providing robustness and maintaining the integrity and balance of the wheelchair.

[0015] The arrangement also includes an elongated push bar, configured for attachment to the handlebar and the frame attachment bar, preferably at the distal ends thereof. A push bar in this context is a structural component that connects the handlebar to the frame attachment bar, acting as a conduit for the pushing forces exerted by the pusher. The push bar's elongated shape enables it to span the distance between the handlebar and the frame attachment bar, ensuring that the forces are evenly distributed across the wheelchair's structure. The configuration for attachment ensures that the push bar can be securely connected to both the handlebar and the frame attachment bar, e.g. at the distal ends, providing overall rigidity of the pushing arrangement. This adds to the robustness, simplicity in design, maintaining structural integrity of the pushing system, whilst allowing for smooth and stable propulsion of the wheelchair even when navigating challenging terrains.

[0016] The arrangement comprises a coupling element configured for engaging with an outer circumference of a section of the frame attachment bar to couple the frame attachment bar with the push bar. A coupling element may be understood as a component that connects two or more parts together, allowing for the transmission of force or motion between them. In this invention, the coupling element engages with the outer circumference of the frame attachment bar, providing a secure connection between the frame attachment bar and the push bar. The engagement with the outer circumference ensures that the coupling element can transmit forces between the two bars without slipping or losing alignment, which is beneficial for maintaining the robustness of the pushing arrangement. The coupling element provides a robust and reliable connection between the frame attachment bar and the push bar, which is essential for the safe and effective operation of the wheelchair.

[0017] The frame attachment bar has an unround outer circumference, and the coupling element has a corresponding unround inner circumference to allow a form-fitting connection in a plurality of orientations of the coupling element, and consequently also the push bar, relative to the frame attachment bar. An unround circumference may be understood as a shape that is not perfectly circular, providing specific angles or edges that can interlock with a correspondingly shaped component. The form-fitting connection facilitated by these unround circumferences ensures that the coupling element and push bar can be positioned in various orientations while still maintaining a secure fit. This design allows for flexibility in the positioning of the push bar, accommodating different user preferences or wheelchair configurations. An effect of this arrangement is the enhanced adaptability of the pushing system, as it can be adjusted to suit various wheelchair designs or user needs without compromising on stability or ease of use, but still is simple in design, keeping bill of materials and production costs low.

[0018] Although it is conceivable that the unround outer circumference is defined by a polygonal outer shape of the frame attachment bar, and the corresponding unround inner circumference of the coupling element has a similar polygonal shape to allow for a mating connection, in further preferred embodiments they could also have other unround shapes that facilitate a secure, form-fitting connection. For example, the unround outer circumference could be polygon shaped such as star-shaped, where the points and valleys of the star engage securely with a corresponding star-shaped inner circumference of the coupling element, preventing any rotational slippage. Another example could be a teethed or serrated shape, where a series of interlocking teeth on the outer circumference of the frame attachment bar mesh precisely with corresponding teeth on the inner circumference of the coupling element. Variants of teethed shapes could include configurations with varying tooth sizes, such as fine or coarse teeth, which would allow for different degrees of adjustability and grip strength depending on the specific application requirements. These varied unround shapes ensure a robust and reliable connection, providing both rotational and axial stability, while accommodating different user needs and wheelchair designs.

[0019] The frame attachment bar is configured as a torsion axle or torsion bar. A torsion axle or bar is a type of axle that can resist twisting forces, providing additional structural support and rigidity to the frame of the wheelchair. In this invention, configuring the frame attachment bar as a torsion axle ensures that the pushing arrangement can withstand the forces exerted during use without bending or deforming. An effect of this feature is that it enhances the durability and longevity of the pushing arrangement, making it capable of enduring the stresses associated with regular use, particularly over uneven surfaces, while maintaining the comfort and safety of the occupant and the pusher.

[0020] In an example, the unround outer circumference of the frame attachment bar is defined by a plurality of grooves and / or raised edges that are evenly distributed over the outer circumference; and the unround inner circumference of the coupling element is defined by a similar plurality of raised edges and / or grooves that are evenly distributed over the inner circumference to allow for a mating connection between the frame attachment bar and the coupling element.

[0021] In an example, the unround outer circumference of the frame attachment bar is defined by a teethed outer surface, and the unround inner circumference of the coupling element is defined by an inner surface that is correspondingly teethed to obtain a secure fixation and allow an adjustable rotational orientation of the push bar with respect to the frame attachment bar by the interlocking teeth.

[0022] In an example, the handlebar and frame attachment bar are configured for use in a substantially horizontal orientation, and the push bar is configured to extend transverse to the handlebar and the frame attachment bar.

[0023] In an example, any one or more of the handlebar, push bar and frame attachment bar has a longitudinal shape selected from the group consisting of: elongated and straight, curved, riser, drop and flat.

[0024] In an example, any one or more of the handlebar, push bar and frame attachment bar has a cross-sectional shape selected from the group consisting of: circular, oval, rectangular, square, polygonal and circle segment.

[0025] In an example, the handlebar and push bar are comprised of a single integrated T-shaped element.

[0026] In an example, the handlebar is comprised of two coaxial elongated rods that are coaxially slidable with respect to each other to allow adjustment of the length of the handlebar.

[0027] In an example, the push bar is comprised of two coaxial elongated rods that are coaxially slidable with respect to each other to allow for adjustment of the length of the push bar.

[0028] In an example, the length of the handlebar and / or push bar can be secured by a locking element.

[0029] In an example, the length of the handlebar and / or push bar can be extended in discrete steps.

[0030] In an example, the coupling element comprises one or more of the group consisting of: clamps, bolts, screws, quick-release fasteners.

[0031] In an example, the frame attachment bar is comprised of two coaxial elongated rods that are coaxially slidable with respect to each other to allow for adjustment of the length of the frame attachment bar.

[0032] In an example, the outer of the two coaxial elongated rods of the frame attachment bar has a teethed inner surface, and the inner of the two coaxial elongated rods has a teethed outer surface to obtain a secure fixation and allow an adjustable rotational orientation of the inner rod in relation to the outer rod.

[0033] In an example, the frame attachment bar comprises connectors at two distal ends to couple with the frame of the wheelchair.

[0034] In an example, the connectors at the two distal ends of the frame attachment bar have an elliptical shape for receiving and accommodating a range of diameters of the wheelchair frame.

[0035] In an example, any one or more of the handlebar, push bar and frame attachment bar is comprised of a material selected from the group consisting of: steel, steel alloy, aluminum, aluminum alloy and carbon-comprising material.

[0036] In an example, the frame attachment bar is configured as a torsion bar.

[0037] In an example, the frame attachment bar is configured as a torsion axle configured as a damping mechanism to reduce vibrations and improve ride comfort.

[0038] In an example, the frame attachment bar is configured as a torsion axle configured to withstand a torsional load of up to 1200 Newton-meters (Nm).

[0039] In an example, the coupling element comprises an integrated quick-release mechanism, allowing for rapid attachment and detachment of the push bar from the frame attachment bar, to enhance user convenience and facilitate compact storage or transportation of the wheelchair and pushing arrangement.

[0040] In an example, the frame attachment bar incorporates an internal damping system, comprising elastomeric or hydraulic components, designed to absorb and dissipate vibrations and shocks transmitted through the wheelchair frame, to improve ride comfort and reduce fatigue for the user.

[0041] The present invention will be further elucidated on the basis of the description of a preferred embodiment of a pushing arrangement according to the invention, with reference to the following figures, in which: Fig. 1 shows an isometric front-side view of a pushing arrangement according to the invention mounted on a manual wheelchair in the operating condition; Fig. 2 shows an isometric rear-side view of a pushing arrangement according to the invention mounted on a manual wheelchair in the operating condition; Fig. 3 shows an isometric rear-side view of a pushing arrangement according to the invention mounted on a manual wheelchair in the stored condition; Fig. 4A-C shows the three intermediate steps for bringing the pushing arrangement according to the invention from the stored condition as in fig. 3 to the operation condition as in fig. 1; Fig. 5 shows in more detail an isometric view of one of the storage clamps used for holding the push bar in the stored condition mounted on the original handles of the manual wheelchair; Fig. 6 shows in more detail an isometric view of the frame attachment bar of the pushing arrangement according to the invention; Fig. 7 shows an exploded view of the coupling element around the frame attachment bar according to fig. 6; Fig. 8 shows an isometric view of the part of the coupling element of fig. 7, that contains the push bar insertion hole, in isolation; Fig. 9 shows an exploded view of the right side of the frame attachment bar of fig. 6; Fig. 10 shows an exploded view of the middle section of the frame attachment bar of fig. 6; Fig. 11 shows an exploded view of the locking mechanism parts embedded in the first end of the push bar, that facilitate the locking of the push bar to the coupling element, according to the invention; Fig. 12 shows an exploded view of the parts attached at the second end of the push bar, responsible for locking the handlebar extension length, according to the invention; Fig. 13 shows an exploded view of the locking mechanism parts embedded in the lower end of the extendable handlebar, that facilitate the locking of the push bar to the coupling element, according to the invention; Fig. 14 shows an exploded view of how the handlebar grip and the mirror are mounted on one side of the horizontal tube of the handlebar, according to the invention.

[0042] Fig. 1 shows a pushing arrangement 1 attached to the front of a manual wheelchair 2 in the operating condition. This pushing arrangement 1 is designed to push the manual wheelchair 2 in a reverse direction D, across a ground surface. By attaching the pushing arrangement 1 to the manual wheelchair 2, a pusher can easily push the wheelchair from the front, allowing for a more user-friendly experience. This setup ensures that both the occupant and the pusher face each other, enhancing both verbal and non-verbal communication.

[0043] The pushing arrangement 1 comprises a push bar 3 with an extendable handlebar 4, a frame attachment bar 5 and a coupling element 6. The frame attachment bar 5 is extendable in length, which makes it suitable for manual wheelchairs 2 having different widths, and is mounted horizontally on the front side of the wheelchair between two opposite frame tube sections 7. This involves placing the clamps 8 (shown in more detail in fig. 6), that are present on both sides of the extendable frame attachment bar 5, over the opposite frame tube sections 7 and tightening the fastening handles 10 (shown in more detail in fig. 6) of the clamps 8. This procedure has to be performed once prior to the first use of the pushing arrangement 1, after which the frame attachment bar 5 can remain fixed on the wheelchair, even when the pushing arrangement 1 is not in the operating condition.

[0044] The frame attachment bar 5 is designed to fit wheelchair frame tube sections 7 having a wide range of frame tube diameters, preferably between 18 and 32 millimeters. Moreover, frame attachment bar 5 can be mounted on frame tubes having any orientation, as long as the frame tube sections 7 on both sides of the frame attachment bar 4 run approximately parallel to each other and are approximately straight over a certain minimum distance, preferably 6 centimeters. For instance, in the embodiment of figure 1, the frame attachment bar 5 could also be mounted between the two vertical frame tube sections of the manual wheelchair 2, directly above the displayed mounting position.

[0045] The outer tube 11 (shown in more detail in fig. 6) of the frame attachment bar 5 has a toothed outside surface with teeth stretching in the longitudinal direction and radially distributed along the circumference of the outer tube 11, preferably with a radial spacing of 9 degrees. The coupling element 6 consists of two parts that are designed to clamp the outer tube of the frame attachment bar 5 in between by tightening four bolts 12 (shown in more detail in fig. 7). Each of these two parts contains a teeth pattern matched to the teeth distribution on the outside surface of the outer tube. As a result, the coupling element 6 can be mounted on discrete positions, preferably every 9 degrees, around the frame attachment bar 5, in which the matching teeth patterns result in a rigid connection. In this way, the hole in the coupling element 6, configured for insertion of the push bar 3, can always be oriented such that the push bar 3 is at a convenient angle α with respect to the ground surface in the operating condition, independent on the rotation of the frame attachment bar 5 around its longitudinal axis. The procedure of determining the most suitable orientation of the coupling element 6 around the frame attachment bar 5 and fixing it on the frame attachment bar 5 also has to be performed once prior to the first use of the pushing arrangement 1, after which the coupling element 6 can remain fixed on the frame attachment bar 5.

[0046] The extendable push bar 3 can be inserted into the coupling element 6 when the handlebar 4 is fully retracted. The end of the push bar 3 has a conical shape which is matched to the conical shape of the hole in the coupling element 6. As a consequence, there is enough clearance at the beginning of the insertion of the push bar 3 in the coupling element 6, which makes the insertion process easy and user-friendly. At the same time, the conical fit ensures a connection between the push bar 3 and the coupling element 6 with very little play when push bar 3 is fully inserted. The bottom side of the conical insertion hole in coupling element 6 and the bottom side of push bar 3 are both flattened to prevent push bar 3 from rotating around its longitudinal axis after being fully inserted into the coupling element 6.

[0047] After insertion of the push bar 3 into the coupling element 6, the handlebar 4 can be set to the desired height by pushing the button of the handlebar extension lock mechanism 13 and pulling the handlebar 4 out of the push bar 3. The extension length of the handlebar 4 can be locked in discrete steps, preferably approximately every five centimeters, by releasing the button of the handlebar extension lock mechanism 13 at one of these positions. By pulling the handlebar 4 out of the push bar 3, another locking mechanism at the end of the push bar 3 that is inserted into the coupling element 6, is activated, which locks the push bar 3 in the longitudinal direction in the coupling element 6. This locking mechanism can be deactivated again by pushing the button of the handlebar extension lock mechanism 13 and pushing the handlebar 4 in till it is fully retracted, after which the push bar 3 can be pulled out of coupling element 6.

[0048] The handlebar 4 contains a grip 14 and an adjustable mirror 15 at both ends of its horizontal tube section. The purpose of these mirrors 15 is to provide the occupant of the manual wheelchair 2 with a view in the reverse pushing direction D, which makes it more comfortable for the occupant to be pushed backwards.

[0049] Moreover, the pushing arrangement 1 contains two small clamps 16 that are attached on the frame tubes of the manual wheelchair 2 next to the original handles. These clamps are configured to attach to the handlebar grips 14 of the handlebar 4, such that the push bar 3 can be stored on the back of the manual wheelchair 2 when the pushing arrangement 1 is not used.

[0050] Fig. 2 shows the pushing arrangement 1 mounted on manual wheelchair 2 in the operating condition, viewed from the rear side. From this view, the numbering applied to the upper side of the extendable handlebar 4, which indicates the positions at which the handlebar can be locked, is visible.

[0051] In fig. 3, the pushing arrangement 1 is stored at the back of the manual wheelchair 2. In this storage condition, the grips 14 of the handlebar 4 are pressed into the arms of the clamps 16, and the mirrors 15 are folded inwards.

[0052] Fig. 4A to 4C show the intermediate steps required to bring the pushing arrangement 1 from the storage condition displayed in fig. 3 to the operating condition displayed in fig. 1 and 2. In fig. 4A the push bar 3 is lifted out of the storage clamps 16 and is brought to the front of the manual wheelchair 2. In fig. 4B, the push bar 3 is inserted into the coupling element 6. In fig. 4C, the button of the handlebar extension lock mechanism 13 is pressed, the handlebar 4 is set to the desired height and the button of the handlebar extension lock mechanism 13 is released to lock the handlebar 4 at this position. During this operation, the locking mechanism at the end of the push bar 3 that is inserted into coupling element 6 is activated, which locks push bar 3 in the longitudinal direction in coupling element 6. After adjusting the position of the mirrors 15, the operating condition shown in fig. 1 and 2 is reached.

[0053] Fig. 5 shows a more detailed view of one of the storage clamps 16 mounted on one of the frame tubes close to the original handles of the manual wheelchair 2. The storage clamps 16 consist of a base 17 that is clamped around the frame tube by fastening the nut and bolt 18. The base fits on a wide range of frame tube diameters, preferably from 18 to 32 cm, using a strip of filling rubber in between the base ring and the frame tube for the smaller frame tube dimensions. The clamp head 19 can rotate freely over 360 degrees on top of the base 17 to ensure that the clamp head openings of the storage clamp heads on both sides can always be aligned, independent of the direction of the frame tube section their base 17 is mounted to. Besides that, the free rotation ensures that the clamps 16 cannot get damaged when pulling out the push bar 3 in an uncontrolled way.

[0054] Fig. 6 shows the frame attachment bar 5, mounted on two opposite frame tube sections 7 of the manual wheelchair 2, and with the coupling element 6 attached in the middle, in more detail. From this view, it follows that the frame attachment bar consists of an outer tube 11 with a higher density of radially distributed small teeth on the outer surface and an inner tube 21 with a lower density of radially distributed coarse teeth on the outer surface. The inside surface of the outer tube 11 has a radially distributed teeth pattern that is matched to the teeth pattern on the outside of the inner tube 21, such that the inner tube 21 can slide into the outer tube 11 and rotation of the inner tube 21 along its longitudinal axis is locked with respect to the rotation of the outer tube 11 along its rotational axis. As a consequence, any torsion force exerted on the outer tube 11 through coupling element 6, for instance due to the user of the pushing arrangement 1 pushing down on the push bar 3, is divided over both clamps 8 present on both ends of the frame attachment bar 5. The inner tube 21 is centered in the outer tube 11 by means of a coupling ring 22.

[0055] Fig. 7 shows a more detailed view of how the coupling element 6 is mounted on the frame attachment bar 5, by clamping the upper part 23 and a lower part 24 of the coupling element 6 around the frame attachment bar 5 using the four bolts 12. From this view, it is visible that the upper part 23 and the lower part 24 both contain two teeth that interlock with the teeth pattern on the outer tube 11 of the frame attachment bar 5. Furthermore, this view shows that the clamps 8 have an opening at the bottom wide enough for insertion of the frame tube section 7 and a parabolic shaped inner wall. When the frame tube section 7 is inserted into the clamp 8 and the handle 10 is tightened, the frame tube section 7 is pressed against the parabolic shaped inner wall of the clamp 8. Due to the parabolic shape of the inner wall, the inner wall always touches the frame tube section 7 on two sides, independent of the diameter of the frame tube section 7, which is preferably in the range of 18 to 32 centimeters. As a consequence, a rigid connection between the clamp 8 and the frame tube section 7 is established when tightening the handle 10. A thin slab of rubber 25 is present on the parabolic shaped wall of the clamp 8 to increase the friction between the clamp 8 and the frame tube section 7, and to prevent damage to the frame tube section 7 when tightening the handle 10. In an alternative embodiment of the invention, the shape of the clamps 8 can be adjusted to fit frame tube sections 7 having noncylindrical shapes, for instance a square shape.

[0056] Fig. 8 shows a more detailed view of the upper part 23 of the coupling element 6. From this view, it is visible that the conical hole designed for intake of the push bar 3 has a flat side on the bottom. Furthermore, a square hole is visible on the top side of the upper part 23 of the coupling element 6, which is part of the mechanism by which the push bar 3 is locked in the coupling element 6 during extension of the handlebar 4.

[0057] Fig. 9 shows an exploded view of the right side of the frame attachment bar 5 from fig. 7. The clamp 8 is attached to the right side of the outer tube 11 by a welded connection. On the other side of the clamp 8, a threaded hole is present, through which the handle 10 can be inserted. After insertion of the handle through the hole, a pressure cap 26 is screwed on to the end of the threaded rod of the handle 10. The purpose of this pressure cap 26 is to divide the clamping force over a larger area of the frame tube section 7, which prevents damage to the frame tube section 7. Besides that, the pressure cap 26 also acts as an end stop for the handle 10 when it is loosened. Furthermore, a rubber slab 25 is visible that is glued onto the parabolic inner wall of the clamp to increase friction between the clamp 8 and the frame tube section 7.

[0058] Fig. 10 shows an exploded view of the middle section of the frame attachment bar 5 from fig. 7. From this view, it is visible that the inside surface of the outer tube 11 has a radially distributed teeth pattern that is matched to the teeth pattern on the outside of the inner tube 21. The coupling ring 22 is designed to fit the outside teeth pattern of the outer tube 11 as well as the outside teeth pattern of the inner tube 21. The inner tube 21 contains a spacing cap 27 at its end, that is secured by means of a set screw 28 that is inserted through a hole in the inner tube 21 into a threaded hole in the spacing cap 27. The purpose of this spacing cap 27 is, similarly to the purpose of the coupling ring 22, to center the inner tube 21 in the outer tube 11 and to facilitate smooth sliding of the inner tube 21 in the outer tube 11.

[0059] Fig. 11 shows an exploded view of the push bar locking mechanism parts embedded in the conic end of the push bar 3. This part of the locking mechanism consists of a locking mechanism housing 29, which contains a pawl block 30 that is pushed upwards by two springs 31. The locking mechanism housing 29, together with the pawl block 30 and the springs 31, is inserted into the conic end of the push bar 3. The locking mechanism housing 29 is secured in the push bar 3 by means of a screw 32, that is inserted through a hole in the bottom of the push bar 3 and tightened in a threaded hole present on the bottom of the locking mechanism housing 29. The springs 31 press the pawl block 30 upwards through the rectangular hole present on the top side of the conic end of the push bar 3, such that it sticks out of the conic outer surface of the push bar 3 by a few millimeters. When the push bar 3 is locked in the coupling element 6, the pawl block 30 extends through the hole on the top side of the coupling element 6 (visible is fig. 8), which prevents the push bar 3 from being pulled out of the coupling element 6.

[0060] The pawl block 30 contains an internal upward ramp, designed for insertion of the lock release arm 33 (shown in fig. 13), that is attached to the lower end of the handlebar tube 4. When the handlebar 4 is fully retracted, the lock release arm 33, being at an angle matched to the slope of the internal ramp of the pawl block 30, pushes the pawl block 30 down into the locking mechanism housing 29 out of the hole in the coupling element 6. As a result, the push bar 3 is unlocked and can be pulled out of the coupling element 6. When the push bar 3 is inserted into the coupling element 6 again and the handlebar 4 is extended, the lock release arm 33 moves out of the pawl block 30 during the first few centimeters of the extension movement. As a consequence, the pawl block 30 is pushed upwards by the springs 31 into the hole in the coupling element 6, locking the push bar 3 into the coupling element 6 again.

[0061] Fig. 12 shows an exploded view of the handlebar extension lock mechanism 13, present at the upper end of the push bar 3. The handlebar extension lock mechanism 13 consists of an extension lock housing 34, that contains a lock button 35 that is pressed upwards by four springs 36, and a shaft key 37 that slides into a rectangular longitudinal slot on the bottom side of handlebar tube 4 (visible in fig. 13). The extension lock housing 34 contains a wide ridge on the inside that fits in the wide rectangular slot 38 at the end of the push bar 3. This ridge contains a smaller slot to hold the shaft key 37. The purpose of the shaft key 37 and the ridge that fits in rectangular slot 38, is to transfer any rotational force exerted on the handlebar 4 around the longitudinal axis of the push bar 3 directly through the key 37 and the ridge to the push bar 3. The extension lock housing 34 is further secured to the push bar 3 by screw 39, that is inserted through a hole in the bottom of the extension lock housing 34 and fastened in a threaded hole in the bottom of the push bar 3. The lock button 35 contains a small tapered ridge at the bottom that fits tightly into matched notches 40 at the bottom of the handlebar tube 4 (visible in fig. 13). By pressing the lock button 35, the ridge is moved out of a notch 40 of the handlebar tube 4, after which the handlebar 4 can be pulled in or out freely. By releasing the lock button 35 while moving the handlebar 4 in or out of the push bar 3, the lock button 35 will move up in the following notch 40 that passes, locking the extension of the handlebar 4 at that position.

[0062] Fig. 13 shows an exploded view of the parts embedded in the lower end of the handlebar 4. The lower end of the handlebar tube 4 contains an end cap 41, which holds the lock release arm 33 and centers the handlebar tube 4 in the push bar 3. Screw 42 is inserted through a hole in the lower end of the handlebar tube 4 and tightened into a threaded hole in the end cap 41, after which it extends into a notch present in the lock release arm 33, securing both the end cap 41 and the lock release arm 33 in the end of the handlebar tube 4. From this view, also the longitudinal rectangular slot in which the shaft key 37 moves and the transverse notches 40 for locking the extension length are visible.

[0063] Fig. 14 shows an exploded view of the parts present at an end of the horizontal tube of the handlebar 4. The handlebar grip 14 is secured on the end of the horizontal handlebar tube, which has a reduced diameter, using two screws 43 that tighten the clamps on both sides of the grip 14. The mirror 15 is inserted into the end of the horizontal handlebar tube and secured by means of screw 44. By tightening the screw 44, the part of the mirror 15 that extends into the horizontal handlebar tube expands, clamping the mirror 15 into place.

Claims

1. A pushing arrangement, configured to be arranged on a manual wheelchair, wherein the pushing arrangement is configured to allow a pushing person to push the manual wheelchair in a pushing direction over a ground surface while the manual wheelchair is in a reverse orientation, with a person sitting in the manual wheelchair facing the pushing person, said pushing arrangement comprising: - an elongated handlebar comprising grips attached at each end of the handlebar; - an elongated frame attachment bar, configured for attachment to the frame of the wheelchair; - an elongated push bar, configured for attachment to the handlebar and the frame attachment bar; - a coupling element, configured for engaging with an outer circumference of a section of the frame attachment bar, to couple the frame attachment bar with the push bar; wherein the frame attachment bar has an unround outer circumference, and the coupling element has a corresponding unround inner circumference to allow a form fitting connection in a plurality of orientations of the coupling element, and consequently also the push bar, relative to the frame attachment bar; and wherein the frame attachment bar is configured as a torsion axle.

2. The pushing arrangement according to claim 1, wherein: - the unround outer circumference of the frame attachment bar is defined by a plurality of grooves and / or raised edges that are evenly distributed over the outer circumference; and - the unround inner circumference of the coupling element is defined by a similar plurality of raised edges and / or grooves that are evenly distributed over the inner circumference to allow for a mating connection between the frame attachment bar and the coupling element.

3. The pushing arrangement according to claim 1 or 2, wherein the unround outer circumference of the frame attachment bar is defined by a teethed outer surface, and the unround inner circumference of the coupling element is defined by an inner surface that is correspondingly teethed to obtain a secure fixation and allow an adjustable rotational orientation of the push bar with respect to the frame attachment bar by the interlocking teeth.

4. The pushing arrangement according to any of the previous claims, wherein the handlebar and frame attachment bar are configured for use in a substantially horizontal orientation, and the push bar is configured to extend transverse to the handlebar and the frame attachment bar.

5. The pushing arrangement according to any of the previous claims, wherein any one or more of the handlebar, push bar and frame attachment bar has a longitudinal shape selected from the group consisting of: elongated and straight, curved, riser, drop and flat, or wherein any one or more of the handlebar, push bar and frame attachment bar has a cross sectional shape selected from the group consisting of: circular, oval, rectangular, square, polygonal and circle segment.

6. The pushing arrangement according to any of the previous claims, wherein the handlebar and push bar are comprised of a single integrated T-shaped element, and wherein preferably the handlebar is comprised of two coaxial elongated rods that are coaxially slidable with respect to each other to allow adjustment of the length of the handlebar.

7. The pushing arrangement according to any of the previous claims, wherein the push bar is comprised of two coaxial elongated rods that are coaxially slidable with respect to each other to allow for adjustment of the length of the push bar.

8. The pushing arrangement according to any of the previous claims 7 or 8, wherein the length of the handlebar and / or push bar can be secured by a locking element, and / or wherein the length of the handlebar and / or push bar can be extended in discrete steps.

9. The pushing arrangement according to any of the previous claims, wherein the frame attachment bar is comprised of two coaxial elongated rods that are coaxially slidable with respect to each other to allow for adjustment of the length of the frame attachment bar, and wherein preferably the outer of the two coaxial elongated rods of the frame attachment bar has a teethed inner surface, and the inner of the two coaxial elongated rods has a teethed outer surface to obtain a secure fixation and allow an adjustable rotational orientation of the inner rod in relation to the outer rod.

10. The pushing arrangement according to any of the previous claims, wherein the frame attachment bar comprises connectors at two distal ends to couple with the frame of the wheelchair, and wherein preferably the connectors at the two distal ends of the frame attachment bar have an elliptical shape for receiving and accommodate a range of diameters of the wheelchair frame.

11. The pushing arrangement according to any of the previous claims, wherein any one or more of the handlebar, push bar and frame attachment bar is comprised of a material selected from the group consisting of: steel, steel alloy, aluminum, aluminum alloy and carbon-comprising material.

12. The pushing arrangement according to any of the previous claims, wherein the frame attachment bar is configured as a torsion bar, preferably to withstand a torsional load of up to 1200 Newton-meters (Nm).

13. The pushing arrangement according to any of the previous claims, wherein the frame attachment bar is configured as a torsion axle configured as a damping mechanism to reduce vibrations and improve ride comfort.

14. The pushing arrangement according to any of the previous claims, wherein the coupling element comprises an integrated quick-release mechanism, allowing for rapid attachment and detachment of the push bar from the frame attachment bar, to enhance user convenience and facilitating compact storage or transportation of the wheelchair and pushing arrangement.

15. The pushing arrangement according to any of the previous claims, wherein the frame attachment bar incorporates an internal damping system, comprising elastomeric or hydraulic components, designed to absorb and dissipate vibrations and shocks transmitted through the wheelchair frame, to improve ride comfort and reducing fatigue for the user.

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