EP3452000B1 - Collapsible mobility aid - Google Patents

Description

The invention relates to a foldable mobility aid with two frame elements, on each of which at least one wheel is attached or can be attached, and a folding mechanism, by which the frame elements are connected to one another and a distance between the frame elements in a first position of the folding mechanism at a transport distance of about a second position of the folding mechanism can be adjusted to a working distance, the folding mechanism having a central element with a slide arranged movably relative thereto, at least two connecting arms, which are each articulated on a frame element and on the central element, and at least two levers, each on a connecting arm and on are arranged on the slider, the pivot axes about which the levers are pivotably arranged on the connecting arms and on the slider (10) being in one plane when the folding mechanism (6) is in the second position.

Mobility aids within the meaning of the present invention are orthopedic devices for people with limited mobility. Mobility aids can be, for example, wheelchairs, walking aids or walkers, or buggies or other devices and devices that increase mobility. Such devices and in particular foldable wheelchairs have long been known from the prior art. For example, the US 8,419,047 B2 and the WO 2015/034372 A1 each such a foldable wheelchair. The aim of the folding mechanism is to be able to reduce the distance between the two frame elements for transporting the wheelchair. In this way, the wheelchair can be stowed away to save space for transport.

With a wheelchair according to the U.S. 5,782,483 B1 the dimensions can also be adjusted when using the wheelchair. Pivotally interconnected alignment struts are articulated to cross members, additionally for this purpose they are pivotally connected to a guide sleeve. Rotational movements of the element carrying the seat are avoided when folding the wheelchair and thus changing the dimensions.

A generic wheelchair is, for example, from GB 2 125 740A known. From the US 2015/0245963 A1 a similar wheelchair is known. While the first two documents only have connecting arms attached to the two frame elements as a folding mechanism, between which there is a simple hinge with a stop, the latter application has a folding mechanism as described in the preamble of claim 1 . The advantage lies in the two levers, which are each arranged between a connecting arm and the slider of the central element. This ensures that when the foldable wheelchair is folded up, i.e. when the folding mechanism is transferred from the second position to the first position, it is ensured that the folding mechanism is folded in or, in the reverse process, unfolded on both sides, i.e. towards both frame elements , takes place equally quickly and thus homogeneously.

A foldable mobility aid involves the risk that the mobility aid will also be folded up unintentionally, for example accidentally, although this is not intended. As a rule, there is a seat cushion or a seat cover between the two frame elements, on which the user of the mobility aid sits. This exerts a force on the two frame members connected to that cover or pad that is directed towards the other frame member and so could tend to move the folding mechanism from the second position to the first position, albeit this is not desired in this situation. In the US 2015/0245963 A1 this problem is solved in that the folding mechanism is moved a little beyond the dead center of the folding mechanism when the folding mechanism is transferred from the first position to the second position, ie when the folding mechanism is unfolded. In this way, pressure on the two frame elements of the wheelchair cannot lead to the foldable wheelchair being accidentally folded up. The disadvantage, however, is on the one hand that for folding the folding mechanism, ie for transferring the folding mechanism from the second position to the first position, the two frame elements must first be moved away from each other in order to move the folding mechanism over the dead center again. On the other hand, it is disadvantageous that the movement of the folding mechanism past the dead center causes play within the system, which can lead to rattling and a general feeling of insecurity and the feeling of inferior quality of the wheelchair, although objectively speaking this is not the case.

In the US 6,572,133 B1 another embodiment of a folding mechanism is described which, in the fully unfolded state, ie in the second position of the folding mechanism, is far removed from the dead center of the arrangement. In the fully unfolded state, the respective connecting arms of the folding mechanism therefore do not run exactly or almost perpendicularly on the longitudinal extension of the central element, but have a clear angle which can be between 40° and 45° in the document mentioned. There are various connecting arms that have a corresponding angle in different directions, as is known from a scissor mechanism. Pressure on the two frame elements would consequently lead to this folding mechanism being pushed together, with the connecting arms, which are tilted backwards in the direction of travel of the wheelchair, for example, being arranged on the slide of the central element, while the connecting arms, which are tilted forwards in the direction of travel of the wheelchair are pivoted, are positioned on the central element itself. Collapsing the folding mechanism through pressure on the frame elements would consequently result in the slide being moved relative to the central element. However, since these two components are locked against one another in the fully unfolded position of the folding mechanism, ie the second position, such guidance is not possible. However, the embodiment shown has the disadvantage that a large number of connecting arms are required and, in addition, the folding mechanism is complicated and therefore expensive.

The invention is therefore based on the object of further developing a generic foldable mobility aid according to the preamble of claim 1 in such a way that rattling and a feeling of insecurity are reliably avoided, the folding mechanism is simple and therefore inexpensive to produce and at the same time the shortest possible transport distance is achieved becomes.

The invention solves the problem set by a foldable mobility aid according to the preamble of claim 1, which is characterized in that the folding mechanism is pretensioned in the direction of the second position, in particular is spring-loaded by a spring element.

This means that the arrangement is exactly at its dead center, so that a pressure on one or both of the frame elements in the direction of the other frame element does not lead to a folding of the folding mechanism and thus the foldable mobility aid and its folding mechanism itself is locked. In this way it is also ensured that in the second position of the folding mechanism there is the maximum possible distance between the two frame elements that can be achieved with the respective folding mechanism. By pivoting the folding mechanism past the dead center, as is known from the prior art, the distance between the two frame elements is reduced again from its maximum value when the dead center is exceeded. This leads to play in the system, which can lead to rattling and a feeling of insecurity and the inferior quality of the mobility aid. This is reliably avoided by the arrangement according to the invention.

Advantageously, the pivot axes about which the connecting arms are arranged pivotably on the frame elements and on the central element are also located in one plane when the folding mechanism is in the second position. Because the connecting arms are also in their dead position or at their dead center, the self-locking of the folding mechanism of the foldable mobility aid is reinforced. It is of course not necessary that the plane in which the pivot axes are located about which the connecting arms are pivotable is the same plane as the arms in which the pivot axes are located about which the levers are pivotable. As a rule, this cannot be achieved and is also not necessary for the function of the foldable mobility aid. It is only important that in the second position of the folding mechanism, i.e. in the unfolded state of the mobility aid, the pivot axes about which the levers can be pivoted are in one plane and the pivot axes about which the pivot arms can be pivoted are also in one plane, however are located on a different level.

According to the invention, the folding mechanism is prestressed in the direction of the second position, in particular spring-loaded by a spring element. In this way it is ensured that even in the event that the dead center of the respective pivoting movement of the lever and/or the connecting arms is not completely reached, accidentally folding the folding mechanism is avoided. The strength of the applied prestressing force, for example the strength of the spring used, can be used to set how much force has to be applied even if the dead center is not reached in order to bring the folding mechanism from the second position into the first position and thus fold the foldable mobility aid together.

The spring element is preferably arranged in such a way that it is tensioned when the folding mechanism is brought from the second position into the first position. This consequently happens when the folding mechanism and the foldable mobility aid are folded together. The energy stored in the spring in this way can be used, for example, when the folding mechanism and the foldable mobility aid are later unfolded, for example by releasing a lock.

Advantageously, the folding mechanism can be locked in the first position by a lock. The locking can be formed by a locking element, for example a locking element, which automatically locks into the locking position as soon as the first position of the folding mechanism is reached. To transfer the folding mechanism from the second position to the first position, for example, the slide of the central element must be pulled or a compressive force must be exerted on it. As soon as the slide has consequently reached the position which it assumes when the folding mechanism is in the first position, a locking element can be actuated automatically, which engages in a locking recess or a locking undercut provided for this purpose. Of course, other locking elements that lock automatically are also conceivable.

In an alternative solution, the lock is actuated manually, for example, as soon as the folding mechanism is in the first position. This can be done by a Lever, an insertable bolt or a push button that is to be actuated.

It has turned out to be advantageous that the folding mechanism can be moved from the first position into the second position by releasing the locking mechanism. This means that it is not necessary, for example, to apply a force to the frame members in order to pull them apart. In this case, the necessary force is preferably provided by the energy stored in the spring element.

As an alternative or in addition to this, it is also possible for the folding mechanism to be arrested and locked itself in the first position, for example by the lever being in a dead center position. In this case, it can make sense to provide a transport lock or safety device that prevents the mobility aid from unfolding accidentally, which would happen if the folding mechanism were accidentally brought out of this dead center position. Such a safeguard can consist, for example, of a securing strap that is fastened to the frame elements of the mobility aid, for example by means of Velcro fasteners or snap fasteners.

In a preferred embodiment, there is a stop on the outer end of at least one of the connecting arms, but preferably on all connecting arms. The frame element rests against this stop when the folding mechanism is in the second position. In order to enable a play-free adjustment here, it is advantageous if the stop is adjustable. The stop element, against which the respective frame element rests when the folding mechanism is in the second position, is in this case, for example, designed to be movable relative to the respective connecting arm.

Advantageously, the central element has a stop against which the slide rests when the folding mechanism is in the second position. This ensures in a particularly simple manner that the slider is only pushed far enough for the folding mechanism to be in the second position, and not can be postponed beyond that. At the same time, however, it is also ensured that the slider is pushed at least far enough for the folding mechanism to be in the second position. In this way, incorrect operation is almost impossible. In a particularly advantageous embodiment, there are latching elements on the slide and/or on the stop, which latch into one another or into the recesses provided as soon as the slide is on the stop and the folding mechanism is in the second position. Exact positioning can be ensured in a particularly simple and reliable manner in this way.

The slider preferably has a grip element. At this point, the required tensile or compressive force can be applied to the slide in order to bring the folding mechanism from the second position into the first position. If it is also necessary to apply a force for the reverse process, this can also be applied to the gripping element.

The folding mechanism preferably has at least four connecting arms, two of which are connected to each of the frame elements and the central element. It is not necessary for a lever to also be arranged on each of the at least four connecting arms. In particular, the levers ensure that the movement of the two frame elements, which are moved towards the central element when the folding mechanism is transferred from the second position to the first position, runs synchronously for both sides. This is achieved by the levers regardless of whether such a lever is arranged on each of the at least four connecting arms. However, it is of course possible to provide corresponding levers on each of the pairs of connections.

In a preferred embodiment of the invention, the pivoting movement of the connecting arms about the pivot axes takes place in different planes. The individual pivoting movements of the connecting arms can be identical in pairs, in particular for the connecting arms which lie opposite one another on the central element and are connected to different frame elements. Due to the pivoting movements in different planes, for example two connecting arms, which lie on the same side of the central element and are connected to the same frame element, the frame elements come to lie on top of one another as soon as the folding mechanism is in the first position. As a result, they do not interfere with each other during storage and a smaller transport distance can be achieved in this way.

Figur 1 -

eine schematische dreidimensionale Ansicht eines Teils einer Mobilitätshilfe,

Figuren 2a und 2b -

eine schematische Draufsicht und eine schematische dreidimensionale Ansicht einer Faltmechanik im vollständig entfalteten Zustand,

Figuren 3a und 3b -

die Darstellungen aus den Figuren 2a und 2b im leicht eingefalteten Zustand,

Figuren 4a und 4b -

die Darstellungen aus den Figuren 2a und 2b im stark eingefalteten Zustand,

Figuren 5a und 5b -

die Darstellungen aus den Figuren 2a und 2b im vollständig zusammengefalteten Zustand,

Figur 6 -

einen vergrößerten Ausschnitt aus einer Faltmechanik und

Figur 7 -

die schematische Darstellung eines Teils einer Mobilitätshilfe.

An exemplary embodiment of the present invention is explained in more detail below with the aid of the attached figures. It shows:

Figure 1 -

a schematic three-dimensional view of part of a mobility aid,

Figures 2a and 2b -

a schematic top view and a schematic three-dimensional view of a folding mechanism in the fully unfolded state,

Figures 3a and 3b -

the depictions from the Figures 2a and 2b in a slightly folded state,

Figures 4a and 4b -

the depictions from the Figures 2a and 2b in the heavily folded state,

Figures 5a and 5b -

the depictions from the Figures 2a and 2b in the fully folded state,

Figure 6 -

an enlarged section of a folding mechanism and

Figure 7 -

the schematic representation of a part of a mobility aid.

figure 1 shows a schematic three-dimensional view of a part of a mobility aid. Two frame elements 2 can be seen, on which axle mounts 4 are present, into which the axles or hubs of a wheel of the mobility aid can be inserted. Between the two frame elements 2 there is a folding mechanism 6 which has a central element 8 on which a slide 10 is located.

There are four connecting arms 12 on the central element 8 which are each arranged on the central element 8 via a first arm pivot axis 14 and on the respective frame element 2 via a second arm pivot axis 16 in each case.

In figure 1 it can also be seen that two levers 18 are fastened both to one of the connecting arms 12 and to the central element 8 . They are pivotably attached to the central element 8 via a first lever pivot axis 20 and connected to the central element 8 via a second lever pivot axis 22 . One recognizes in figure 1 moreover, that there are four connection arms 12 in total, which can be divided into two front and two rear connection arms. The front and rear connecting arms are articulated on the central element 8 at different “heights”. As for example in the Figures 5a and 5b can be seen, this results in the pivoting movement of the front and rear connecting arms taking place in different planes, so that they do not interfere with one another, particularly when the folding mechanism is in the first position, as is the case in FIGS Figures 5a and 5b is shown. In the unfolded state, the in figure 1 is shown, the four connecting arms span a plane. This plane preferably intersects the plane of the seat of the wheelchair or a differently designed mobility aid in the front third of this seat. This increases the stability and the feeling of security for the user of the mobility aid.

Figure 2a shows a schematic plan view of a folding mechanism 6, while Figure 2b the schematic 3D view of the folding mechanism 6 shows. As well as Figure 2a as well as in Figure 2b the folding mechanism is in the second position, i.e. in the fully unfolded state. The distance between the two frame elements 2 is maximum with the selected folding mechanism 6 and thus corresponds to the distance in use. It can be seen that the first arm pivot axes 14, together with the second arm pivot axes 16 for each two opposing connecting arms 12, are in one plane, in Figure 2a so lie in a line. The same also applies to the first lever pivot axes 20 and the second lever pivot axes 22, even if this cannot be seen particularly well from the geometric shape of the lever 18 shown.

The slide 10, which is used in particular in Figure 2b can be seen is in the most rearward position, with in Figure 2a is in the left area in the direction of travel of the mobility aid.

The Figures 3a and 3b and FIGS. 4a and 4b show the representation from FIG Figure 2a and 2b in a slightly and strongly collapsed situation. The slider 10 is moved further to the left as the folding process progresses. In the front area of the slide 10 there is a handle element 24 on which, for example, a pulling element, for example a cord or cord, can be arranged.

In the Figures 5a and 5b the folding mechanism 6 shown is shown in the fully folded situation, ie in the first position. The distance between the two frame elements 2 is minimal and thus corresponds to the transport distance. In particular Figure 5b It is easy to see that the pivoting movements of the two connecting arms 12, which are arranged on the same side of the central element 8, have taken place in different planes. In the exemplary embodiment shown, the connecting arms 12 are arranged one below the other. This ensures that in the first position of the folding mechanism, which is shown in FIGS. 5a and 5b, they are also arranged one above the other and thus do not interfere with folding. As a result, a smaller transport distance is achieved.

figure 6 shows an enlarged section of the folding mechanism. You can see the central element 8 with the slider 10 and the two front connecting arms 12 on which the two levers 18 are located. The respective first arm pivot axes 14 and the second lever pivot axes 22 can also be seen.

At the rear end of the slide there is a gripping element 26 which is set up to at least partially grip a stop 28 when the slide 10 is located on the stop 28 . In this case the folding mechanism 6 is in the second position.

One recognizes in figure 6 especially good one already in figure 1 contained spring element 30, by which the slide 10 is biased towards the stop 28.

figure 7 shows part of a mobility aid in a schematic representation. The frame element 2, which has a horizontal portion 30, can be seen. At this is arranged a seat 32 on which, if the mobility aid is used, the user of the mobility aid sits. The folding mechanism 6 is shown underneath, in which it is easy to see that the various connecting arms 12 are arranged at different heights with respect to the seat surface 32 , ie at different distances from the seat surface 32 . In this position, the connecting arms 12 span a connecting plane 34, which is shown as a dashed line. It can be seen that this imaginary connecting plane 34 intersects the seat surface 32 in the front third of the seat surface 32 . This is not necessary but an advantage since it improves the stability and also the sense of security of a user of the mobility aid.

reference list

2

frame element

4

axle mount

6

folding mechanism

8th

central element

10

slider

12

link arm

14

first arm pivot axis

16

second arm pivot axis

18

lever

20

first lever pivot axis

22

second lever pivot axis

24

grip element

26

gripping element

28

attack

30

horizontal portion

32

seat

34

link arms

Claims (9)

1. A folding mobility aid with

   two frame elements (2), to each of which at least one wheel is fixed or can be fixed and

   a folding mechanism (6) by way of which

   the frame elements (2) are connected to each other and

   a distance between the frame elements (2) can be adjusted in a first position of the folding mechanism (6) to a transport distance and

   in a second position of the folding mechanism (6) to an operation distance,

   the folding mechanism (6) comprising

   a central element (8) with a slide (10) arranged such that it can be moved in relation to said central element,

   at least two connecting arms (12), each of which is articulated on one frame element (2) and the central element (8), and

   at least two levers (18), each of which is articulated on one connecting arm (12) and the slide (10) such that it can be pivoted about pivot axes (20,22),

   the pivot axes (20, 22), about which the levers (18) are pivotably arranged on the connecting arms (12) and the slide (10), are located in one plane when the folding mechanism (6) is in the second position, characterized in that the folding mechanism (6) is pre-loaded towards to the second position, particularly spring-loaded by a spring element.
2. The folding mobility aid according to claim 1, characterized in that the pivot axes (14, 16), about which the connecting arms (12) are pivotably arranged on the frame elements (2) and the central element (8), are located in one plane when the folding mechanism (6) is in the second position.
3. The folding mobility aid according to claim 2, characterized in that the spring element (30) is arranged in such a way that it is tensioned when the folding mechanism (6) is moved from the second position into the first position.
4. The folding mobility aid according to one of the preceding claims, characterized in that the folding mechanism (6) can be locked in the first position by a lock.
5. The folding mobility aid according to one of the preceding claims, characterized in that an adjustable end stop is arranged on at least one connecting arm, said end stop resting on the frame element (2) when the folding mechanism is in the second position.
6. The folding mobility aid according to one of the preceding claims, characterized in that the central element (8) comprises an end stop (28) on which the slide (10) rests when the folding mechanism (6) is in the second position.
7. The folding mobility aid according to one of the preceding claims, characterized in that the slide (10) comprises a grip element (24).
8. A folding mobility aid according to one of the preceding claims, characterized in that the folding mechanism (6) comprises at least four connecting arms (12), of which in each case two are connected with each of the frame elements (2) and the central element (8).
9. The folding mobility aid according to claim 8, characterized in that the pivot movements of the connecting arms (12) about the pivot axes (14, 16) occur in different planes.

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