DE9421544U1 - Collapsible wheelchair - Google Patents

Description

X Sch/EN/Anc-2

Folding wheelchair

The invention relates to a collapsible wheelchair comprising:

a frame comprising: a first sixth frame;

a second side frame substantially identical to the first side frame;

coupling means keeping the two side frames in the same positions and at the same distance from each other, at least in the operating condition; wheels attached to the frame; a seat attached to the frame; and a backrest attached to the frame.

Such a wheelchair is known. In the known wheelchair, the side frames can be moved towards each other by means of an articulated cross connection by exerting a lateral pressure force inwards. In the folded state obtained in this way, the wheelchair has the same dimensions in the vertical plane as in the non-folded state.

The invention aims to design a wheelchair in such a way that, when folded up, it takes up considerably less effective space than the known wheelchair and, for example, has such dimensions that it can be taken on an airplane as hand luggage, which is more practical for a wheelchair user for obvious reasons. The wheelchair user can be transported onto the airplane himself or, if necessary, with the help of third parties. There, the wheelchair can be folded up to dimensions that correspond at most to the maximum permissible dimensions for hand luggage. After the flight, the wheelchair user can immediately use his wheelchair again.

It may also be desirable for other means of transport, such as public transport or a car, that a wheelchair can be folded up to relatively small dimensions.

In view of the above, the invention provides a collapsible wheelchair, characterized in that each side frame comprises:

a first central sub-frame which, in the operating state, extends more or less horizontally, or approximately at the height of the seat; a front sub-frame which, in the

operating state extends obliquely forward from the front of the first middle subframe and carries a relatively small front wheel;

a rear sub-frame extending obliquely rearwardly upwardly from the rear of the first middle sub-frame in the operating state and supporting a relatively large rear wheel and supporting, together with the other rear sub-frame, the backrest;

the front and rear subframes are movable relative to the first middle subframe by means of a hinge connection;

the coupling means are designed as corresponding subframes on spacers that maintain a fixed mutual distance;

Between the front and rear subframes, a second central subframe is mounted, which is articulated relative to these two subframes by means of a hinge connection, in such a way that each side frame and thus the entire frame can be folded together about horizontal hinge axis lines until three subframes are at least substantially on top of each other; and

There are attachment means between a central subframe and at least one of the other subframes which determine a stable operating position of the wheelchairs.

It is advantageous to be able to adjust the individual mutual relationships, in particular the angular positions of the composing parts, according to the user's wishes.

For this purpose, the wheelchair may be characterized in that the position of the hinge connection between the first middle sub-frame and the rear sub-frame is adjustable along the rear sub-frames.

The wheelchair can also be characterized in that the position of the hinge connection between the second middle sub-frame and the front sub-frame is adjustable along this front sub-frame.

The wheelchair can also have the feature that the length of the second middle subframe is adjustable.

Unlike the known wheelchair briefly described above, in which an articulated scissor construction couples the two side frames together, in the wheelchair according to the invention the side frames must be as inherently rigid as possible in the vertical plane. For this purpose the wheelchair according to the invention can be characterized in that the first middle subframe in the main plane of the side frame or in the area bordering the hinge connection with the front subframe has larger dimensions in this plane than in the transverse direction, increasing the bending stiffness. For example, the first middle subframe can be more or less sheet-metal-shaped, in any case have an increasing vertical dimension in the direction of its front. However, in order to save as much weight as possible, an open-worked structure can also be used.

To a somewhat lesser extent, the requirement for increased bending stiffness also applies to the front sub-frame. In connection with this, the wheelchair can have the characteristic that the front sub-frame in the main plane of the side frame, at least in the area adjacent to the hinge connection with the first middle sub-frame, has a larger dimension that increases the bending stiffness in the plane than in the transverse direction.

In order to be able to fold the wheelchair as comfortably as possible after the wheels have been removed, the

The special feature is that the rear wheels are detachably coupled to the rear subframe by means of a quick coupling.

In particular, this variant may be characterized in that the rear subframe carries a detachable block which carries an axle to which a rear wheel is detachably coupled, which block carries the axle at an angle determining the angle of the rear wheel in the vertical plane.

The longitudinal position of the rear wheels is a major factor in determining the balance of the wheelchair. Since this balance is different for each individual user and can also depend on the setting of the individual parts that can be adjusted relative to one another and parts of adjustable length, the wheelchair can have the special feature that the position of the axle in the direction of travel of the rear wheel is adjustable.

In a specific embodiment, the wheelchair has the special feature that the first two middle subframes are connected to each other by a first spacer.

In another embodiment, the wheelchair has the special feature that the block is hingedly connected to the second middle subframe and the two second middle subframes are connected to each other by a second spacer.

In particular, a combination of the latter two features gives a strong and stable mechanical structure, whereby the complete space under said two spacers is freely accessible. This may be of importance when coupling the wheelchair to an auxiliary device as described in the applicant's earlier, non-prepublished Dutch patent application with the number NL93 013232, which is based on the European priority application EP-93.201601.1 of 4 June 1993.

Even greater rigidity is ensured with a variant in which the two rear subframes are connected to each other by a third spacer in the area adjacent to the first middle subframe.

A very simple, reliable design of the wheelchair according to the invention is characterized in that the stop means have a pin that can be adjusted axially by operating means against the action of spring means, which pin is mounted in a subframe and can cooperate in a securing manner with a hole in an adjacent subframe.

Preferably, the structure of the wheelchair

symmetrical. In this connection, the said design may have the particularity that two pins are present in corresponding positions in its two frames.

The design in which the two pins are connected by a flexible pulling element, for example a cord or a cable, is easy to use, so that a user can adjust both pins from their securing interaction with the respective hole against the effect of the respective spring means by exerting a pulling force on this pulling element.

The invention will now be explained with reference to the accompanying drawings, in which:

Figure 1 is a partially broken away perspective view of a wheelchair according to the invention;

Figure 2 is a partially broken away perspective view on an enlarged scale of the structure in the area of the coupling block for the left rear wheel;

Figure 3 is a schematic side view of the wheelchair showing the manner of folding;

Figure 4 is a perspective view of the wheelchair in the folded state after the rear wheels have been removed ;

Figure 5 is a side view of a variant;

Figure 6 is a side view of the wheelchair according to Figure 5 coupled to an auxiliary device according to NL-93 01322; and

Figure 7 is a partially broken away perspective view of a detail of a variant.

In all figures, identical components are always provided with the same reference symbols.

Figure 1 shows a folding wheelchair according to the invention. The wheelchair comprises a left side frame and a right side frame 2'. These side frames 2 and 2' are identical, only mirror images. For the sake of brevity of the description, only the side frame 2, if applicable, will be described.

The side frame 2 comprises: a first central sub-frame 4 which, in the operating state shown in Figure 1, extends more or less horizontally, in any case approximately at the height of a seat 5;

a front subframe 6 which, in the operating state shown in Figure 1, extends obliquely forwards and downwards from the front of the first middle subframe 4 and carries a support member 7 for a footrest and a relatively small, pivotable front wheel 8;

a rear subframe 9 which, in the operating state shown in the figure, extends obliquely rearwardly upwards from the rear of the first middle subframe 4 and carries a relatively large rear wheel 29 and, together with the other rear subframe 9 ^1, carries a backrest 10. The front subframe 6 and the rear subframe 9 are movable in an articulated manner relative to the first middle subframe 4 by means of respective hinge connections 11, 12. The support member 7 connects the left and right front subframes to one another and in this way contributes to the self-supporting character of the wheelchair.

The side frames 2, 2 ¹ are connected by coupling means. These are designed as spacers that keep corresponding sub-frames at a fixed mutual distance. The first middle sub-frames 4, 4' are coupled by means of a spacer 13. The rear sub-frames 9, 9 ¹ are coupled by a spacer 14. Between the front sub-frame 6 and the rear sub-frame 9, a second middle sub-frame 17 is attached, which is articulated relative to these two sub-frames by means of hinge connections 15, 16, in such a way that each side frame 2, 2' and thus the entire frame can be folded together about horizontal hinge axis lines until the three sub-frames 6, 4, 9,; 6 ¹ , 4 ¹ , 9'

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in any case, they essentially lie on top of one another. Between the first middle sub-frame 4 and the front sub-frame 6 there are stops that determine a stable operating position of the wheelchair 1. For this purpose, a pin 18 is connected to the front sub-frame 6, which can be moved in a slotted hole 19 in the first middle sub-frame 4 that is concentric with the hinge 11.

The position of the hinge connection 12 between the first middle subframe 4 and 9 is adjustable along this rear subframe 9. In this context, particular reference is made to Figure 2. A bush 20 is slidable along the rear subframe 9 and can be fixed in selected positions relative to it by means of holes 21 and a pin 22. The bush 20 carries two eyelets 23 which articulate the first middle subframe 4 by means of a bolt 24. The corresponding bushes 20, 20' are connected to one another by a tube 25 which serves as a spacer, thus stiffening the construction, but also fulfils the function of acting as a support for the seat 5 which is carried at the front by the spacer 13.

The position of the articulation 15 between the second middle subframe 17 and the front subframe 6 is adjustable along this front subframe. For this purpose, a series of holes 39 is provided in this subframe 6.

The length of the second middle sub-frame 17 is adjustable. The design of this adjustability is of a type known per se, related to the adjustment of the bushing 20 relative to the rear sub-frame 9, as shown in Figure 2. This does not need to be discussed further here.

In a completely analogous manner, the support member 7 is adjustable relative to the front subframe 6.

The first middle subframe 4 has a larger dimension in the main plane of the side frame than in the transverse direction, which increases the bending stiffness of this plane. Figure 1 shows that the dimension in question increases to the extent that the distance to the hinge connection decreases.

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The front subframe 6 has a larger dimension in the main plane of the side frame than in the transverse direction, which increases the bending stiffness in this plane. Since this front subframe 6 is subject to a less strong moment than the first middle subframe 4, the dimension in question does not need to be as large as in the first middle subframe 4.

A rear wheel 29 is coupled to the rear subframe 9 by means of a quick coupling 40 known per se. In this context, particular reference is made to Figure 2. The rear subframe 9 carries a block 26 which is detachably connected to it by means of a bolt 25 and which carries an axle 27 to which the rear wheel 29 is detachably coupled by means of the quick coupling 40. The block 26 carries the axle 27 at an angle which determines the angle of the rear wheel 29 in the vertical plane. The block 26 carries the spacer 14 in an articulated manner. The second middle subframe 17 is connected to the spacer 14 by means of a welded connection 28. The position of the axle 27 can in any case be adjusted approximately in the direction of travel of the rear wheel 29. For this purpose, the block 26 is provided with a test of the 30 in which the axle 27 can be moved. Fixing in a desired position is carried out by means of a nut 31. The block 26 can be easily removed so that, if desired, it can be replaced by another block with which the user can obtain a different desired angle of the rear wheel 29 in the vertical plane.

Figure 3 shows a side view of the wheelchair 1, from which it becomes clear how the folding takes place. It will be clear that the respective sub-frames 9, 4, 6, 17 are mutually hinged and foldable until they have a reciprocal position with minimal space requirement.

Figure 4 shows this folded state in perspective view.

Figure 5 shows a side view of a wheelchair 32 which differs from the wheelchair 1 according to Figures 1-4 in that the first middle sub-frame 33, unlike the

Subframe 4 according to Figures 1-4 has an open structure. Due to the perforations, designated 34 for convenience, the bending stiffness is reduced only to a negligible extent, but a significant reduction in weight is achieved.

It should be noted that in the situation shown in Figure 5 and in Figure 6 to be discussed below, the blocks 26, 26' have an inverted position. This gives the user even greater adjustability of the position of the rear wheels 29, 29·.

Figure 6 shows the coupling of the wheelchair 32 to an auxiliary device according to the applicant's earlier, non-prepublished Dutch patent application with the number NL-93 01322, which is based on the European priority application EP-93.201601.1 of June 4, 1993. This auxiliary device 35 can be coupled to the wheelchair 32 in a very simple manner and then offers the user a hand control 36 for driving and steering the wheelchair 32 by means of the front wheel 37, which is part of the auxiliary device 35. The front wheels 8, 8 ¹ of the wheelchair 32 are raised off the ground when the wheelchair 32 and the auxiliary device 35 are coupled. The combination 32, 35 thus drives exclusively on the rear wheels 29, 29' and the front wheel 37.

Essential for the coupling between the

The auxiliary device 35 and the wheelchair 32 is the structure according to the invention, according to which the spacers 13, 14 are freely accessible from the front, without the accessibility in question being hindered by the presence of an articulated cross frame according to the prior art. The rear sub-frames 9, 9 ¹ are coupled at their upper sides, in the region of the backrest 10, by a handle 38 which can be used by a third person to push the wheelchair by hand.

.It should be noted that the block 26 is designed so that it is essentially an integral part of the frame. Figure 2 in particular clearly shows this aspect. The block 26 is designed so that it

can support the tubular subframe 9 in a rigid manner. The block 26 should be made of a material that can withstand the relevant mechanical stress. One such material is aluminum, for example.

It is noted that the second middle sub-frame 17 has an adjustable length. In combination with the series of fastening holes 39 corresponding to the positions at which the second middle sub-frame 17 is connected to the front sub-frame 9, this ensures the desired adjustability with the correct collapsibility, that is, collapsibility into the position shown in Figure 4 in which the respective sub-frames lie on top of each other with minimal space requirements.

The frame of the wheelchair according to the invention is completely self-supporting and highly rigid. If required, width adjustment is very easy to implement. The individual cross connections shown in Figure 1 between the two side frames can be replaced with elements of an adapted length. These adjustments are completely linear and correspond exactly to the desired width adjustment. In known collapsible wheelchairs with scissor mechanisms, for example, such adjustments are not linear with the desired width adjustment.

Various materials can be considered for the frame. For example, these are metals, especially light materials such as aluminum, plastics, possibly with fiber reinforcement, with high mechanical strength, for example ABS, and further sandwich and composite structures.

It will further be appreciated that the spacer may also be located at other positions in the vicinity of the hinge joints 11, depending on design considerations.

Finally, with reference to the embodiment according to the figure and figure 6, it is pointed out that the through holes or perforations 3 4 in the middle sub-frame 33 have dimensions which in the transverse direction

relative to the longitudinal direction of the subframe 33, in the direction from the hinge connection 11 to the hinge connection 12.

Figure 7 shows that an axially adjustable locking pin 51 is mounted on both sides of the first subframe 6. This includes a collar 52 which serves as a stop for a compression spring 53 which serves to move the pin outwards into a blind hole 54 in the middle subframe 4', with which the pin 51 can thus cooperate in a locking manner. Due to the distance between the hinge connection 11' and the pin and hole connection 51, 54, the subframes 4 ¹ , 6 are thus connected to one another in a way that is secured against rotation. A cord 55 connects the pins 51 in the left and right frames to one another. By exerting a pulling force on the cord 55, a user can pull the pins 51 inwards against the effect of the respective springs 53, whereby the hinge lock between the subframes 4', 6 is removed and the wheelchair can be folded up.

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Claims (15)

12 X Sch/EN/Anc-2 ANS EXAMS 1. A folding wheelchair comprising: a framework which includes: a first side frame; a second side frame substantially the same as the first side frame; coupling means which keep the two said side frames in the same positions at the same distance from each other at least in the operating state; wheels attached to the frame; a seat attached to the frame; and a backrest attached to the frame, characterized in that each side frame comprises: a first central sub-frame which, in the operating state, extends more or less horizontally, or approximately at the height of the seat; a front sub-frame, which is located in the operating state extends obliquely forward from the front of the first middle subframe and carries a relatively small front wheel; a rear sub-frame extending obliquely rearwardly upwardly from the rear of the first middle sub-frame in the operating state and supporting a relatively large rear wheel and supporting, together with the other rear sub-frame, the backrest; the front and rear subframes are movable relative to the first middle subframe by means of a hinge connection; the coupling means are designed as corresponding subframes on spacers that maintain a fixed mutual distance; Between the front and rear subframes, a second middle subframe is mounted, which is hinged to these two subframes, in which · in such a way that each side frame and thus the entire frame can be folded together about horizontal hinge axis lines, until three sub-frames are at least substantially on top of each other; and There are attachment means between a central subframe and at least one of the other subframes which determine a stable operating position of the wheelchairs. 2. Wheelchair according to claim 1, characterized in that the position of the hinge connection between the first middle subframe and the rear subframe is adjustable along the rear subframe. 3. Wheelchair according to claim 1, characterized in that the position of the hinge connection between the first middle subframe and the rear subframe is adjustable along the front subframe. 4. Wheelchair according to claim 1, characterized in that the length of the middle subframe is adjustable. 5. Wheelchair according to claim 1, characterized in that the first middle subframe in the main plane of the side frame or in the area adjacent to the hinge connection with the front subframe has a larger dimension that increases the bending stiffness of this plane than in the transverse direction. 6. Wheelchair according to claim 5, characterized in that the front subframe in the main plane of the side frame or in the area adjacent to the hinge connection with the first middle subframe has a larger dimension that increases the bending stiffness of this plane than in the transverse direction. 7. Wheelchair according to claim 1, characterized in that the rear wheels are detachably coupled to the rear subframe by means of a quick coupling. 8. Wheelchair according to claim 7, characterized in that the rear sub-frame carries a detachable block carrying an axle to which a rear wheel is detachably coupled, which block carries the axle at an angle determining the angle of the rear wheel in the vertical plane. 9. Wheelchair according to claim 8, characterized in that the position of the axle in the direction of travel of the rear wheel is adjustable. 10. Wheelchair according to claim 1, characterized characterized in that the two first middle subframes are connected to each other by a first spacer. 11. Wheelchair according to claim 8, characterized in that the block is hingedly connected to the second middle subframe and the two second middle subframes are mutually connected by a second spacer. 12. Wheelchair according to claim 1, characterized characterized in that the two rear subframes are mutually connected by a third spacer in the area adjacent to the first middle subframe. 13. Wheelchair according to claim 1, characterized characterized in that the stop means comprise a pin which can be axially adjusted by operating means against the action of spring means, which pin is mounted in a sub-frame and can cooperate in a securing manner with a hole in an adjacent sub-frame. 14. Wheelchair according to claim 13, characterized in that two pins are present in corresponding positions in its two frames. 15. Wheelchair according to claim 13, characterized characterized in that the two pins are connected by a flexible pulling element, for example a cord or a cable, in such a way that a user can adjust both pins from their securing interaction with the respective hole by exerting a pulling force on this pulling element, counter to the action of the respective spring means. ••••••9 · » *·«