WO2023209498A1

WO2023209498A1 - Foldable wheel

Info

Publication number: WO2023209498A1
Application number: PCT/IB2023/054005
Authority: WO
Inventors: Andrea MOCELLIN; Johan NIEUWENDIJK; Ruud VAN GOOL; Dennis Vervoorn
Original assignee: Revolve Mobility Bv
Priority date: 2022-04-29
Filing date: 2023-04-19
Publication date: 2023-11-02

Abstract

Foldable wheel including: a first hub (3) and a second hub (4) that can be moved relative to each other along the wheel axis, and a plurality of spokes (5A-5B) pivotally connecting the hubs (3,4) with a plurality of rubberized sectors (6). The foldable wheel is arranged so that starting from an extended condition (1C) in which the sectors (6) form the rim (2) which has aa maximum diameter, the partial spacing apart between the first (3) and the second (4) hub subjects the spokes (5A-5B) to traction so as to reduce the diameter of the rim (2) with respect to the maximum diameter.

Description

"Foldable wheel"

Field of the invention

The present invention relates to foldable or collapsible wheels comprising a rim with rubberi zed sectors which can be configured, starting from an extended condition for forming the rim, in a collapsed condition for minimum overall dimension of the wheel .

State of the prior art

Collapsible wheels are described and illustrated for example in documents US-8371659 , US- 8833864 , US- 2012 / 0032497 , US-2014 / 0097666 and US-2015/ 0084398 .

Foldable wheels thus made can advantageously be used, for example , for equipping foldable bicycles with the aim of reducing overall dimension thereof and facilitating transportation and putting it away when not being used .

The foldable wheel described in Patent EP3344472 on behal f of Andrea Mocellin corresponds to the precharacterising part of claim 1 : it comprises a double hub and spokes which pivotal ly connect the hubs with the sectors of the rim . The spokes have a substantially fixed length and the hubs can be moved between an approached condition, corresponding to the extended condition of the sectors in which the rim is formed, and a spaced apart condition in which the spokes extend substantially parallel to the wheel axis and the sectors of the rim are folded .

The main drawback of this solution lies in the compression stress that the circular sectors trans fer to the spokes during the operation of the wheel . As a matter of fact , it is known that elongated bodies , such as the spokes of a wheel , when subj ected to a compression load have a signi ficantly lower resistance with respect to when subj ected to a tensile load .

Summary of the invention

The obj ect of the present invention is to overcome the aforementioned drawback and this obj ect is attained due to a foldable wheel of the type defined in the precharacterising part of claim 1 , whose distinctive characteristic lies in the fact that the rubberi zed sectors are connected to each other through first and second hinge blocks alternating with each other and substantially arranged respectively in a first plane and in a second plane orthogonal to the wheel axis , the spokes comprising a first and a second group of spokes alternating with each other which respectively connect the first hub with the first hinge blocks and the second hub with the second hinge blocks , wherein the sectors of the rim can be configured from an extended condition for forming the rim corresponding to the proximal position of the two hubs wherein the first and second plane are substantially coincident and the spokes are arranged substantially radially, to a collapsed condition corresponding to the distal position of the two hubs in which the first and second plane are spaced from each other along the wheel axi s and the sectors extend longitudinally between the two hubs with the spokes arranged substantially parallel to the wheel axis , the arrangement being such that starting from the extended condition for forming the rim, wherein the rim has a maximum diameter, a subsequent partial spacing apart between the first and second hub subj ects the spokes to traction so as to reduce the diameter of the rim with respect to the maximum diameter .

Thanks to this solution idea, the wheel according to the invention has a signi ficantly higher operating load resistance with respect to a similar wheel in which the spokes are compression loaded : the traction of the spokes operated by the partial spacing apart of the hubs actually allows , contrary to the case of foldable wheels known to date , to signi ficantly reduce the weight thereof considering the same resistance .

According to a preferred embodiment , the foldable wheel according to the invention comprises a manually operated tensioning mechanism designed to carry out the partial spacing apart between the first and second hub which subj ects the spokes to traction . This allows to facilitate the step for unfolding the wheel wherein the hubs are moved away to tension the spokes .

In a preferred embodiment of the foldable wheel according to the invention, the aforementioned tensioning mechanism includes a knob designed to operate a bushing, coaxial to the shaft and provided in its radially external end of an external thread and, in its radially internal end, of an abutment edge with an adj ustment element arranged coaxially to the first hub . In this manner, rotating the knob allows to further facilitate the unfolding step in which they should be moved away from the hubs .

In a further embodiment of the wheel according to the invention, each of the spokes comprises a pair of rods configured as an articulated parallelogram .

In a further embodiment of the wheel , each of the pairs of rods configured as an articulated parallelogram comprises elastic means to further facilitate the unfolding of the wheel .

In a further embodiment , the foldable wheel according to the invention comprises manually operated tie rod means designed to act on at least one group of hinge blocks so as to faci litate the folding of the wheel .

In a further embodiment , the spokes are at least four, preferably six .

In a further embodiment , the hinge blocks connect the ends of the sectors so as to allow their rotation from closed to open and they are configured to rotate on the corresponding spoke so as to maintain a condition of parallelism with the corresponding hub during the unfolding of the wheel .

In a further embodiment of the foldable wheel according to the invention, the hinge blocks comprise locking members each including locking means adapted to cooperate with a respective pair of reinforcement blocks fixed to each end of the sectors of the rim .

In a further embodiment , the foldable wheel according to the invention equips a wheelchair for the disabled .

In a further embodiment , the foldable wheel according to the invention comprises a push-rim integrated in the circular sectors .

In a further embodiment of the foldable wheel according to the invention, the first or second hinge blocks are integrated in the push-rim .

The sectors of the rim are preferably, though not necessarily, six .

Detailed description of the invention

The invention will now be described in detail , purely by way of non-limiting example , with reference to the attached drawings , wherein :

- figure 1 is a side elevational view of a foldable wheel according to the invention in the collapsed condition,

- figure 2 is a side elevational view of a foldable wheel according to the invention in the extended use condition,

- figures 3 and 4 are views similar to figures 1 and 2 which show the wheel when passing from the collapsed condition to the extended condition,

- figure 5 is a side elevational view - from a di f ferent angle - of the foldable wheel according to the invention in the extended condition,

- figure 6 is a plan view of figure 1 ,

- figures 7- 9 are front views which show the wheel when passing from the collapsed condition to the extended condition,

- figure 10 is an elevational view which shows the beginning of the folding of the wheel , figures 11- 13 are three perspective views of di f ferent embodiments of the wheel according to the invention to which there are applied auxiliary elements to facilitate the folding and/or unfolding,

- figures 14 and 15 are perspective views and in larger scale of some detail s of an embodiment of the wheel according to the invention,

- figure 16 is a perspective view of a further embodiment of the wheel according to the invention in an extended configuration .

Detailed description of the invention

Initially with reference to figures 2 and 5 , the foldable wheel according to the invention, indicated with 1A in its extended condition of normal use , essentially comprises a rubberi zed rim 2 , a pair of coaxial hubs 3 , 4 and a series of spokes divided into two groups generally indicated with 5A-5B which pivotingly interconnect the hubs 3 , 4 with the rim 2 , with the characteristics which will be addressed hereinafter . The rim 2 in turn consists of a series of sectors 6 , connected to each other through respective hinge blocks 11A- 11B which will be addressed hereinafter, and each sector 6 includes an arched rubber portion 8 carried by a rigid support 7 which, in the extended condition of the wheel 1A, extends according to a chord of the rim 2 .

In particular, the hinge blocks 11A- 11B are configured so as to allow the rotation of the sectors 6 from closed to open, as shown in f igure 3 .

In the case of the illustrated example , the sectors 6 are six, same case applying to the spokes 5A, 5B . However, in the context of the present invention there may be provided for solutions with a higher number of sectors , with the aim of attaining greater compactness of the wheel in the folded condition thereof , or with a smaller number of sectors to lighten the weight of the wheel .

As observable in greater detail in figure 2 , the hub 3 is fixedly mounted on an end of a central shaft 9 , and the hub 4 is mounted on the shaft 9 in a slidable coaxial fashion .

Now, with reference to figure 5 , the spokes of the first group 5A are pivoted - in the radially internal end - to respective support appendages 10A of the first hub 3 and - in the opposite end - to the respective first hinge blocks 11A arranged equally spaced apart on the axially external edge of the extended wheel . The spokes of the second group 5B are pivoted - in the radially internal end - to respective support appendages 10B of the second hub 4 and - in the opposite end - to the respective second hinge blocks 11B, alternating with respect to the first , arranged equally spaced apart on the axially internal edge of the extended wheel .

Figures 1 and 6 show the foldable wheel in the collapsed condition, shown with IB : in such configuration, the hubs 3 , 4 are spaced from each other, the spokes 5A-5B extend substantially axially along the central shaft 9 , adj acent with respect thereto , and the sectors 6 of the rim 2 also extend longitudinally between the two hubs 3 , 4 , externally to the spokes 5A-5B .

With speci fic reference to figure 6 , conveniently according to the invention, in the collapsed condition IB of the wheel all the f irst hinge blocks 11A are aligned with respect to a f irst plane A orthogonal to the wheel axis , and all the second hinge blocks 11B are aligned with respect to a second plane B, parallel and distant from the first plane substantially as much as the length of the spokes 5A-5B .

As better observable in f igure 13 , in the preferred embodiment but non-limiting embodiment of the wheel according to the invention shown in the figures , each spoke comprises a pair of rods 36 , 37 configured as an articulated parallelogram to facilitate the assembly and disassembly of the wheel which will be addressed hereinafter ; di f ferent embodiments according to the invention, not shown in the figures , may provide for spokes with a single rod or comprising three or more rods .

Now, with reference to figure 14 , in the extended condition of the wheel , the hinge blocks 11A- 11B, hinged to the respective radially external ends of the spokes 5A-5B through pins 33 , are shaped as shown in detail in figures 14- 15 and comprise locking members 14 each including locking means 15 adapted to cooperate with a respective pair of reinforcement blocks 16 fixed using fixing means 33 to each end of the sectors 6 of the rim 2 .

Besides allowing the rotation of the sectors 6 from closed to open, the hinge blocks 11A- 11B rotate on the corresponding spoke 5A-5B so as to maintain a condition of parallelism with the corresponding hub 3 , 4 when unfolding the wheel . The locking members 14 act so as stably and rigidly hold the rim 2 in the extended condition during the operation of the wheel .

Also in this case , the embodiments of the hinge blocks and of the locking members of the sectors of the rim shown in the figures shall not be deemed as limiting but di f ferent types of system for rotating and locking the sectors fall within the scope of protection of the present invention .

Figures 1 to 4 and 6 to 9 show the passage of the wheel from the collapsed configuration ID ( figures 1 and 6 ) , to the extended condition 1A ( figures 2 and 9 ) passing through a first intermediate configuration IB ( figures 3 and 7 ) , and a second intermediate configuration 1C ( figures 4 and 8 ) and vice versa, as follows .

From the minimum overall dimensions collapsed condition of the wheel ID, the hub 4 is axially approached to the hub 3 , configuration of the wheel IB shown in figures 3 and 7 , while the spokes 5A-5B simultaneously rotate until they are arranged substantially perpendicularly to the shaft 9 when the two hubs 3 , 4 touch each other in the configuration of the wheel 1C shown in the figures 4 and 8 , wherein the first plane A and the second plane B of the respective hinge blocks 11A- 11B are substantially coincident .

Such configuration of the wheel 1C, in which the rim 2 formed by the radial arrangement of the sectors 6 has a maximum diameter, is shown as singularity configuration .

The arrangement of the wheel is such that , starting from such singularity condition, a subsequent partial spacing apart between the first 3 and the second 4 hub, and therefore a partial moving away of the planes A and B once again, subj ects the spokes 5A-5B pivoted to the respective sectors 6 to traction, compression loading the rim 2 reducing its diameter with respect to that of the singularity condition .

Thanks to this solution idea, in the final extended use configuration 1A of the wheel according to the invention, the spokes are conveniently subj ected to a traction force typical of the spoked wheels which confer to the wheel the capacity to withstand use loads greater than a similar wheel in which the spokes are compression loaded .

In the embodiment of the wheel according to the invention shown in the figures , for example as shown in figures 2 and 16 , along a radially external portion of the rim there is provided for a push-rim integrated in the circular sectors 6 which confers to the wheel the possibility to equip a foldable wheelchair for the disabled .

In a configuration of the wheel thus made , the first hinge blocks 11A are integrated in the push-rim 35 while the second blocks 11B are arranged on the axially internal edge of the circular sectors 6 creating an alternating position of the blocks which confers to the wheel a broad space for the tyre .

In the embodiment of the invention shown in the figures , the synchronisation of the sectors 6 is facilitated during the entire folding movement of the wheel due to the alignment of all hinge blocks perpendicularly to the main axis of the wheel obtained due to the pivoted parallelogram shape with two rods 36 , 37 of the spokes 5A-5B .

In an embodiment of the invention not shown in the figures , the synchronisation of the folding movement of the wheel may be further improved using means for synchronising the movement of all the spokes on one side of the rim . This can be obtained by means of a third group of spokes , connected to a third hub, not shown in the figures . Now, with reference to figure 11 , the folding of the wheel can be facilitated using removable manual means 18 designed to exert a traction force through a series of tensioners 20 each connected - at a first end thereof

- to one of the hinge blocks 11A of the first group, and

- at the opposite end - to a ring 19 . Therefore , pulling the ring 19 upwards allows to exert a traction force on the first group of hinge blocks 11A opposing the force of gravity, starting the movement of the hub 4 from the singularity position more easily synchronising the folding movement of all hinge blocks 11A- 11B .

Now, with reference to figure 13 , in an embodiment according to the invention, the unfolding of the wheel is facilitated through an elastic means 21 designed to generate a force torque which acts on each of the hinge blocks 11A- 11B, helping the components of the wheel to move from the aforementioned singularity condition 1C towards the fully unfolded condition 1A.

In the embodiment shown in the figures , such elastic means comprise a spring 21 constrained - in its first end - to a radially internal appendage 23 of the rod 37 of each of the parallelogram-like spokes 5A-5B, and - in the opposite end - constrained to a radially external appendage provided for on the rod 36 of each of the spokes 5A-5B .

Now, with reference to figure 12 , in an embodiment according to the invention, the achievement of the final unfolding 1A of the wheel from said singularity condition 1C is facilitated through a manually operated tensioning mechanism 25 , 26 , 30 designed to carry out the partial spacing apart of the two hubs 3 , 4 which subj ects the spokes 5A-5B to traction .

Such tensioning mechanism comprises a knob 25 which rotatably acts on a bushing 26 coaxial to the shaft 9 and provided - in its radially external end - with an external thread 27 , and - in its radially internal end - with an abutment edge 28 with an adj ustment element 30 coaxially screwed to the second hub 4 by means of an external thread 31 .

Manually operating on the knob 25 allows to axially translate the bushing 26 towards the first hub 3 , provided with an internal thread 29 adapted to cooperate with the external thread 27 of the bushing 26 , so that a subsequent rotation of the bushing 26 allows the abutment edge 28 to partially move away the hub 4 from the hub 3 tensioning the spokes 5A-5B and therefore arranging the wheel in the final unfolded position .

The thread 31 of the adj ustment element 30 allows to adj ust the amount of preload to be conferred to the spokes 5A-5B .

The foldable wheel according to the invention is susceptible to several applications to various types of vehicles , for example pushchairs for the disabled, so- called wheelchairs .

Obviously, the described applications are j ust examples of the various pos sible uses of the foldable wheel according to the invention, whose construction details and embodiments may widely vary with respect to what has been described and illustrated, without departing from the scope of protection of the present invention as defined in the claims that follow .

Claims

1. A foldable wheel (1) including: a first hub (3) and a second hub (4) that can be moved relative to each other along the axis of the wheel between a mutually approached (proximal) position and a mutually spaced (distal) position, a rim (2) comprising a first and a second group of rubberized sectors (6) , a plurality of spokes (5A-5B) pivotally connecting said hubs (3,4) with said sectors (6) , characterised in that said rubberized sectors (6) are connected to each other by means of first (11A) and second (11B) hinge blocks alternating with each other and substantially arranged respectively in a first plane (A) and in a second plane (B) orthogonal to the axis of the wheel, said spokes comprising a first (5A) and a second (5B) group of spokes alternating with each other which respectively connect the first hub (3) with the first hinge blocks (11A) and the second hub (4) with the second hinge blocks (11B) , wherein the sectors (6) of the rim (2) can be configured from an extended condition (1C) for forming the rim (2) corresponding to said proximal position of the two hubs (3,4) wherein said first (A) and second (B) plane are substantially coincident and said spokes (5A-5B) are arranged substantially radially, to a collapsed condition (ID) corresponding to said distal position of the two hubs (3,4) wherein said first (A) and second (B) plane are spaced from each other along the wheel axis and said sectors (6) extend longitudinally between said two hubs (3,4) with said spokes (5A-5B) arranged substantially parallel to the wheel axis, the arrangement being such that starting from said extended condition (1C) forming the rim (2) , in which the rim (2) has a maximum diameter, a subsequent partial spacing apart between said first (3) and second (4) hub subjects said spokes (5A-5B) to traction so as to reduce the diameter of the rim (2) with respect to said maximum diameter .

2. Foldable wheel (1) according to claim 1 characterised in that it comprises a manually operated tensioning mechanism (25,26,30) designed to carry out said partial spacing apart between the first (2) and second (3) hub which subjects said spokes (5A-5B) to traction .

3. Foldable wheel (1) according to claim 2 characterised in that said tensioning mechanism includes a knob (25) designed to operate a bushing (26) , coaxial to said shaft (9) and provided - in its radially external end - with an external thread (27) and - in its radially internal end - with an abutment edge (28) with an adjustment element (30) arranged coaxially to the second hub ( 4 ) .

4. Foldable wheel (1) according to any one of the preceding claims, characterised in that each of said spokes (5A-5B) comprises a pair of rods (36,37) configured as an articulated parallelogram.

5. Foldable wheel (1) according to any one of the preceding claims, characterised in that each of said pairs of rods (36, 37) configured as an articulated parallelogram comprises elastic means (21) to facilitate said unfolding.

6. Foldable wheel (1) according to any one of the preceding claims, characterised in that it comprises manually operated tie rod means (18) designed to act on at least one of said groups of hinge blocks (11A-11B) so as to facilitate the folding of the wheel (1) from said extended configuration (1C) to said collapsed condition (ID) .

7. Foldable wheel (1) according to any one of the preceding claims, characterised in that said spokes (5A- 5B) are at least four.

8. Foldable wheel (1) according to any one of the preceding claims, characterised in that said hinge blocks (11A-11B) connect the ends of said sectors (6) so as to allow their rotation from closed to open and they are configured to rotate on the corresponding spoke (5A- 5B) so as to maintain a condition of parallelism with the corresponding hub (3,4) during the unfolding of the wheel ( 1 ) .

9. Foldable wheel (1) according to any one of the preceding claims, characterised in that said hinge blocks (11A-11B) comprise locking members (14) each including locking means (15) adapted to cooperate with a respective pair of reinforcement blocks (16) fixed to each end of the sectors (6) of the rim (2) .

10. Foldable wheel (1) according to one or more of the preceding claims, characterised in that it equips a wheelchair for the disabled.

11. Foldable wheel (1) according to claim 10, characterised in that it comprises a push-rim (35) integrated in said sectors (6) of the rim (2) .

12. Foldable wheel (1) according to claim 11, characterised in that said first (11A) or second (11B) hinge blocks are integrated in said push-rim (35) .

13. Veh icle characterised in that it is provided with foldable wheels (1) according to one or more of claims 1-12.

14. Vehicle, particularly a foldable wheelchair for the disabled, characterised in that it is provided with foldable wheels (1) according to one or more of claims 1-12.