Stroller wheels and a stroller having the wheels

Abstract

The present invention provides a wheel for a stroller, comprising an inner hub for connection to an axle, an outer rim for engagement with the ground during use, and a plurality of spokes connected between the inner hub and the outer rim, the spokes being flexible.

Description

Technical Field

[0001] The present invention relates to wheels of a baby stroller and a baby stroller having the wheels. The present invention also relates to a method of providing a suspension to a baby stroller. The present invention also relates to wheels of other small vehicles or rollable appliances or articles such as a wheeled suitcase.

Background Art

[0002] A baby stroller is a very well-known appliance for carrying infants or small children. Usually, a baby stroller has a seat assembly disposed on a chassis having one or more wheels to facilitate movement of the baby stroller. FIG. 1 is a schematic view of a baby stroller described in co-pending International Application No. WO2022 / 101517 of the same applicant.

[0003] FIG. 1 shows the baby stroller 10 in a deployed state. The baby stroller 10 generally comprises a sub-frame in the form of a chassis assembly 11 to which a handle assembly 26 is connected, and a seat assembly 28. In this example, the seat assembly 28 is attached to the handle assembly 26 by seat attachment means 30. As can be seen from the figure, in normal use, in the deployed state, usually, the backrest is substantially in an upright position. The backrest is preferably capable of being partially or fully reclined backwards. The seat base 28b usually remains in a generally horizontal position when the baby stroller 10 is in the illustrated deployed state.

[0004] A pair of frontwardly extending wheel support legs 14 and a pair of rearwardly extending wheel support legs 16 are rotatably attached to the central body portion 12 of the chassis assembly 11. There are front wheels 18 at the distal ends of the frontwardly extending legs 14 and rear wheels at the distal ends of the rearwardly extending legs 16.

[0005] Typically, the rear wheel assembly 20 is configured to be rotatable about a substantially horizontal axis. The front wheel assembly 18 typically can rotate about a horizontal axis and further includes a front wheel 22 configured to be rotatable about a substantially vertical axis, thus providing a potential steering function for enhancing the maneuverability of the stroller 10.

[0006] In known strollers, the wheel assemblies can take many different forms. Further, although the description herein relates to the wheels of a stroller, it should be noted that these wheels can equally be used in other small vehicles such as golf carts, wheelchairs, golf trolleys, shopping trolleys, bicycles and tricycles, and any other small vehicles. For example, the wheels can also be provided as the wheels of a suitcase or a rolling bag.

[0007] Devices such as strollers have a generally simple structure, so it is not appropriate or desirable to incorporate overly complex mechanisms. However, it is desirable for a stroller to provide a smooth moving experience for the infant or small child carried therein. Similarly, in the case of other small vehicles such as golf carts, wheelchairs, golf trolleys, and shopping trolleys, it is desirable for the vehicle to move smoothly during normal use and to easily overcome the undulations of the ground on which the vehicle is pushed.

[0008] Such suspensions have been tried and used in such buggies, but they are generally complex in structure and thus expensive. An example can be found in CN114030524, which provides a spring-based suspension system connected to the frame elements of a stroller.

[0009] US2020 / 114687, US2020207150, US2017341,464, WO2013 / 138548, US2006 / 113016 disclose examples of wheels including flexible spokes connected between an inner hub and an outer rim of a wheel of a large vehicle. SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

[0010] A simple suspension mechanism for a baby stroller or other such small vehicle is desired.

Means for Solving the Problems

[0011] According to a first aspect of the present invention, there is provided a wheel for a small vehicle such as a baby stroller, the wheel comprising an inner hub for connection to an axle, an outer rim for engagement with the ground in use, and a plurality of spokes connected between the hub and the outer rim, the spokes being flexible.

[0012] It can be provided on a baby stroller or other small vehicle, and there is provided a simple and robust means for ensuring that the vehicle has a suspension, which can provide a smooth riding comfort for the person riding or a comfortable experience for the user pushing the vehicle. This wheel is suitable for a vehicle driven by manual operation, i.e., by the operator pushing or pulling the vehicle to move it.

[0013] In one embodiment, the spokes have a thickness or cross-sectional area that decreases from a radially inner position to a radially outer position or vice versa, i.e., the spokes have a thickness or cross-sectional area that decreases from a radially inner position to a radially outer position. In other words, the spokes become more flexible as the distance from the center in the radial direction increases. This biases the degree of bending of the spokes to be greater at positions farther from the center of the wheel (i.e., positions farther from the junction of the spokes and the wheel hub). As will be described later, this provides a beneficial two-stage compression effect in use. Although multi-stage compression can also be achieved by varying the thickness, shape, material, etc. of the spokes, in practice, two-stage compression is preferred.

[0014] In one embodiment, the spoke has a thickness or cross-sectional area that continuously decreases from a radially inner position at the connection with the inner hub to a radially outer position at the connection with the outer rim. In an alternative configuration, the spoke has a thickness or cross-sectional area that continuously increases from a radially inner position at the connection with the inner hub to a radially outer position at the connection with the outer rim. In a preferred example, the thickness of the spoke is the magnitude of the cross-sectional area of the spoke.

[0015] In one embodiment, the spoke is varied in thickness or cross-sectional area so as to provide a two-stage suspension effect in use.

[0016] In one embodiment, one or more of the spokes are varied in thickness or cross-sectional area so as to deform to define a knee when a first force is applied. Preferably, the spokes are arranged such that the knees of adjacent spokes contact each other, but the spokes may also be arranged at intervals such that knees are formed in use but adjacent spokes do not contact each other.

[0017] Accordingly, the first-stage suspension effect is typically provided when a first level of force, which may occur in normal everyday use, is applied. For example, when used in a baby stroller, knees or kinks are generated in the spokes when crossing a stone or descending a curb. This commonly occurs when pushing the baby stroller and ensures that a person riding in the baby stroller experiences a relatively high level of comfort.

[0018] In one embodiment, after contacting the defined knee adjacent to the spoke, the thickness is varied such that the remaining portion of the spoke contacts only when the force exceeds a defined threshold value. The knee is generally generated at a point where the thickness changes due to a change applied along the length of the spoke, thereby facilitating or biasing the deformation at that point. In other examples, instead of varying the thickness, other variations of the spoke can be used to determine the generation position of the knee. In one example, the spoke is varied in shape (e.g., cross-sectional shape) rather than thickness to facilitate the generation of the knee during use, i.e., from a flat rectangle to a cylindrical shape in the center, or having a twist such that there is a "weaker" area in the center of the spoke.

[0019] Accordingly, a second stage or level of suspension is provided. Further contact between the spokes occurs only when the user experiences a higher force while the knee is already in contact. This typically occurs during normal but less common use of the stroller, for example, when the user accidentally presses the stroller against a high curb, or descends from an unexpectedly large step. The specific details of the force required to cause the initial knee contact and the subsequent spoke contact can be selected and controlled by varying the material or thickness (or shape) of the spokes of the wheel.

[0020] In one embodiment, each spoke is connected to the inner hub at a certain circumferential position and to the outer rim at a different circumferential position such that the spoke is inclined between the inner hub and the outer rim to define an acute angle with the tangent to the hub or the rim.

[0021] In one embodiment, a radius is provided at the connection between at least one, preferably all, of the spokes and the outer rim.

[0022] In one embodiment, a radius is provided at the connection between at least one, preferably all, of the spokes and the inner hub.

[0023] In one embodiment, the wheel is a formed wheel.

[0024] In one embodiment, the wheel is an integrally formed wheel.

[0025] In one embodiment, the wheel is formed with an overall uniform composition.

[0026] In one embodiment, the wheel is formed with a composition that varies along the length of the spoke.

[0027] In one embodiment, the diameter of the wheel is 10 - 50 cm, preferably 18 - 28 cm. These dimensions are given as a preferred range but are not limiting. They represent typical wheel diameters for a baby stroller or small vehicles such as a golf cart, wheelchair, golf trolley, and shopping trolley.

[0028] In one embodiment, a variation according to the radius is given to the axial width of the formed wheel. Preferably, the wheel is thicker at a position radially inside than at a position radially outside. In other words, axially, the wheel becomes thicker as it approaches the center. This provides an efficient and effective way to vary the amount of material of some or all of the spokes according to the radius.

[0029] According to a second aspect of the present invention, there is provided a baby stroller having a chassis, a seat, and at least three legs, with wheels provided on each leg to facilitate movement, wherein at least one of the wheels is a wheel according to the first aspect of the present invention.

[0030] According to a third aspect of the present invention, there is provided a method of providing a suspension for a baby stroller, the method including providing a plurality of wheels on a baby stroller having a chassis, a seat, and one or more wheel support legs, wherein at least one of the wheels includes an inner hub for connection to an axle, an outer rim for engagement with the ground during use, and a plurality of spokes connected between the hub and the outer rim, the spokes being flexible.

[0031] According to a further aspect of the present invention, there is provided a small vehicle having one or more wheels to facilitate movement, wherein at least one of the wheels is a wheel according to the first aspect of the present invention. In one example, the vehicle is selected from the group consisting of a baby stroller, a golf cart, a wheelchair, a golf trolley, and a shopping trolley.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0033]

Figure 1

Figures 2A - 2D

Figures 3A - 3D

Figures 4A - 4B

Figures 5A - 5B

Figures 6A - 6C

Figures 7A - 7B

Mode for Carrying Out the Invention

[0034] Wheels for small vehicles such as baby carriages or golf carts are provided. The wheel includes an inner hub for connection, for example, directly to an axle or via a bearing or bearing assembly, and an outer rim for engagement with the ground during use. A plurality of spokes are provided that connect between the hub and the rim. The spokes are flexible and act to provide suspension and control of the position relative to the ground for a baby carriage or golf cart during use. This wheel provides a simple and effective way to provide suspension for small vehicles such as baby carriages. Thus, the comfort of a person riding in a baby carriage, such as an infant or toddler, can be enhanced without the need to provide a complex control unit on the frame or on the baby carriage itself.

[0035] Referring again to FIG. 1 showing a schematic view of a baby carriage, it can be seen that this baby carriage includes a plurality of wheels provided at the ends of legs 14 and 16. FIGS. 2A - 2D show examples of wheels used for a baby carriage as shown in FIG. 1. Of course, it will be understood that this wheel can be provided for any baby carriage or indeed for any small vehicle such as a wheelchair, a golf cart, a shopping trolley, or other such systems.

[0036] Referring to FIGS. 2A - 2C, the wheel includes an inner hub 32 and an outer rim 34. A plurality of spokes 36 are provided that couple the inner hub 32 and the outer rim 34. In the illustrated example, all the spokes are substantially the same, but in another example, spokes of different configurations can be provided for the same wheel. An opening 38 is formed between each adjacent pair of the provided spokes 36, the function of which will be described in more detail later. In the example of FIGS. 2A - 2C, the opening is substantially triangular in shape, although the sides are not necessarily straight lines.

[0037] The spokes are preferably arranged generally radially, but are not perpendicular to the inner hub 32. In the illustrated example, the spokes form an acute angle θ with the tangent to the hub in the stationary configuration. The spokes also form an acute angle with the tangent to the outer rim. Although the angle is the same in the illustrated example, it need not be the same in other examples.

[0038] In a preferred embodiment, the wheel is provided as a one-piece component. In other examples, the wheel may be formed of several molded parts that are assembled together to form the entire wheel structure. For example, although it is preferably provided as a one-piece component, in another example, the spokes can also be provided as separate components that are assembled with the hub and rim to form the wheel. In this case, the spokes can also be provided as springs, helical springs, leaf springs, etc. that are connected to the hub or the rim. The spokes can be integrated with one of the hub or the rim and provided without being integrated with the other of the hub and the rim. In this example, the spokes can also be formed of a material different from that of the hub and / or the rim.

[0039] The wheel is preferably formed of a plastic material and usually has other materials incorporated therein. For example, in one example, the wheel is formed of a plastic with glass fibers incorporated therein to provide additional strength to the wheel. Importantly, by varying the components of the molding material, the strength and flexibility of the various parts of the wheel are determined. In another example, the wheel is formed of a rubber material with other materials optionally incorporated therein. Those skilled in the art will know how to achieve such effects.

[0040] The rigidity of the spokes is selected such that the wheel is effectively provided with an internal suspension mechanism during use. This ensures that a person riding in a baby stroller or indeed any other small vehicle to which the wheel is attached does not experience discomfort due to the unevenness or lack of smoothness of the ground or surface on which the vehicle is placed.

[0041] Referring to FIG. 2D, an enlarged portion of the wheel is shown. As described above, an opening 38 is provided between each adjacent pair of spokes. The width A of the spoke at the radially inner portion of each spoke 40 is substantially greater than the width B in the radially outer region 42. The effect of varying the thickness of the spoke according to its radial position is to bias the spoke, so that when a force is applied to the rim, i.e., when the wheel hits an object or rides over an unevenness on the ground, the wheel does not deform uniformly, but rather a point of large flexion along its radial length can be determined or controlled.

[0042] In the illustrated example, when a relatively low level of force is first applied, the radially outer region of the spoke elastically deforms and moves to the right in the example shown in FIG. 2D. When this occurs, the adjacent spokes 36 are similarly deformed due to the position and presence of the outer rim 34. A chain reaction occurs and several spokes will similarly deform, gradually with a decreasing amount of deformation.

[0043] After one or more spokes have deformed by a certain amount, the adjacent spokes come into contact with each other in the radially outer region and no further spoke deformation will occur unless a further compressive force is applied.

[0044] In the normal use of the wheel, for example when attached to a baby stroller, the spoke deformation during impact is of this extent. However, after the outer regions of the spokes in a particular part of the wheel come into contact due to the aforementioned deformation, when a greater force is applied to the wheel, the thicker portion below the spoke closer to the center of the wheel in the radial direction will deform until it engages with the adjacent spoke.

[0045] Therefore, due to the shape and configuration of this spoke, that is, by providing a spoke with a thickness that varies radially from a position with a relatively thick radially inner configuration to a position with a thin radially outer position, a two-stage compression process becomes possible. This means that the wheel effectively has two operating modes, that is, two suspension modes that can be provided during use.

[0046] Figures 4A and 4B show exemplary embodiments of the spokes used in any of the wheels of FIGS. 1-3. In FIG. 4A, the spoke has a continuous circular cross-section along its length, but the material composition is varied to create a more flexible region or point 35 at a desired location. Preferably, the more flexible region or point 35 is at 30-70% along the direction from the joint at the hub outward toward the rim.

[0047] In the example of FIG. 4B, the spoke is shaped to have a cross-section that also decreases toward the center so as to create a more flexible region or point 35 at a desired location while having a consistent shape. When compressed in the first-stage response (of the two-stage) of the flexible spoke, a knee is created at this position 35.

[0048] In other examples, the spoke is shaped such that the cross-sectional shape changes along its length. In other words, the cross-sectional shape (circular, elliptical, triangular, rectangular, running track-shaped, etc.) is not consistent along the length of the spoke. In a non-limiting example shown, the region near the hub has a substantially running track-shaped or rectangular cross-section. The cross-section is stepped so that it becomes circular at a predetermined point of 30-70% along the direction from the joint at the hub outward toward the rim and then returns to a different shape such as substantially running track-shaped or rectangular.

[0049] The point where the cross-section of the spoke in this example is circular is preferably slightly smaller in cross-section (the numerical value of the cross-sectional area is smaller at this circular point than on either side of this circular point) so that the generation of the knee at this position is biased during use.

[0050] Figures 5A and 5B are schematic views of a further example of a stroller wheel. In this example, the cross-section of each spoke is elliptical. Also, since the dimensions of the elliptical cross-section decrease as the radial distance increases, the spokes generally become thinner towards the rim of the wheel. The elliptical cross-section provides the great advantage that the outer surface is smooth and curved at any point on the spoke. This reduces the chance that dirt or debris, which the stroller wheels will inevitably encounter when used outdoors, will get stuck in the wheels. Therefore, the chance that dirt or debris such as stones or mud will get trapped between the spokes is reduced. Therefore, by providing spokes with a continuous smooth outer surface, any possible adverse effects on the function of the spokes are avoided or reduced.

[0051] In another example, the spokes have a circular cross-section, which provides advantages corresponding to those of spokes with an elliptical cross-section.

[0052] Referring to Figures 6A and 6B, an example of a wheel is shown to which a radial force F, which may be caused by engagement with undulations on the surface on which the wheel rolls, is applied. The force F can typically be the reaction force to the weight of the stroller, or actually the reaction force to the downward force applied to the wheel at a certain point in time. Figure 6A shows a rasterized version of the wheel indicating the relative stresses applied to the components of the wheel. Figure 6B clearly shows the relative deformation of the individual spokes within the wheel.

[0053] For example, the wheel may roll over a stone on a pavement or fall into a crack or hole in the pavement. In fact, in the example shown, the wheel appears to be on a flat surface, but this is merely for the purpose of illustration. It will be understood that the force applied to the wheel at that point is radially inwards.

[0054] In the spokes of this wheel, the aforementioned first-stage deformation has occurred. The radially outer regions of adjacent spoke pairs are in contact. Looking at the pair of bottom spokes 44 and 46 in FIGS. 6A and 6B, a deformation has occurred such that both spokes 44 and 46 are generally deformed into a bent shape. In this example, a contact point or knee 48 is established between the two spokes. The knee is generated at a specific position along the length of the spoke, and that position is controlled by a change in thickness along the length of the spoke and / or a change in the composition of the material from which the spoke is made.

[0055] Due to this effect, the first spoke 44 and the second spoke 46 approach each other (compared to the spoke pairs in the uncompressed portion above the wheel). For example, refer to the relative separation of the topmost spoke pair 54 and 56 at this point in rotation. Nevertheless, the first spoke 44 of the bottommost spoke pair still arches away from the second spoke 46, and the distance between the paired spokes is maintained in the middle region of the spoke. The distance C between the spokes is maintained in the radially inner regions of spokes 46 and 44.

[0056] The materials of spokes 44 and 46, of course, contact at the knee, and the remaining portions of the non-contacting spokes are the thicker portions closer to the radially inner side. Although the material from which the spoke is made is still deformable at this stage, a greater force is required to further deform it compared to the more radially outer portion of the spoke. In other words, a greater force is required for the inner regions of the spokes to contact each other at this stage, and thus the spoke configuration effectively provides a second-stage compression cycle. By selectively varying the spoke width to decrease radially such that the second radially inner region of the spoke can interact only when the radially outer region has first deformed and defined a contact point between adjacent spokes, the interaction of the spokes is controlled. The fact that the radially inner region is thicker means that a greater force is required to achieve deformation of the spoke at this stage.

[0057] It will be appreciated that the same two-stage compression effect can be achieved without adjacent spokes contacting at the knee. In other words, this can be easily achieved by the fact that when the first thinner portion of the spoke deforms according to the function, the second thicker portion does not deform until the force applied thereto reaches a threshold level where force is required. In fact, in some examples, it may be possible to achieve a two-stage compression or suspension effect even without a knee being generated in any of the spokes.

[0058] This can be further understood with reference to FIG. 6C. In this example, a wheel under a light load is shown. Wheel 55 includes a plurality of spokes, such as 57 and 59, in the upper half of wheel 55. The wheel is under a light load, and in this state, there is no deformation of spokes 57 and 59 in the upper half of the wheel. However, spokes in the lower side or lower half of the wheel, such as 61, 63, are deformed in the outer region. As can be seen from the figure, the thickness of the spoke decreases as the radial distance increases, and thus becomes thinner along the length from hub 32 to rim 34. As a result, all deformations of the spokes in the lower part of the wheel are outside the region indicated by the dashed line (preferably a circle) 65. Inside line 65, the spokes throughout the wheel are not affected. Therefore, a two-stage compression is achieved without necessarily having contact between adjacent spokes.

[0059] This is brought about as a result of a change in material composition, thickness, or shape along the length of the spoke. For example, if each spoke is formed of a helical spring having a first region with a certain spring constant and a second region with a different spring constant, when pressure is applied to the spoke, for example, along its axial length, a two-stage compression is brought about.

[0060] As another example, each spoke may be provided as a hydraulic mechanism or a hydraulic spring including members attached in a nested manner such that, for example, they slide relative to each other when a force is applied. In both of the above examples, the spokes are typically provided in a simple radial configuration connecting the hub to the outer rim or, when more than one annular region is provided, to any intermediate rim.

[0061] Looking again at FIG. 2 (particularly FIG. 2C), it can be seen that in this example the thickness of the wheel is not uniform radially. In other words, the greater the radial distance, the smaller the thickness X of the wheel compared to the thickness Y in the radially inner region. This further provides a means to control the relative flexibility along the length of the spoke. In particular, by making the thickness X of the radially outer portion of the spoke thinner than the thickness Y of the radially inner portion, the deformation of the spoke is biased to occur first in this radially outer region rather than in the radially inner region where the axial (in the direction of the wheel's axis of rotation) length Y is longer. For example, alternative configurations are possible where X is the same as Y or in fact X is greater than Y.

[0062] Preferably, the material composition of the spoke does not vary along the length of the spoke such that the change in flexibility results only from changes in the radial width and thickness (i.e., axial). However, in one example, the material composition is further controlled to impart different degrees of flexibility or rigidity to the spoke along its length.

[0063] Referring to FIG. 3, a second example of the wheel is shown. The general configuration is the same as in FIGS. 2A - 2D, but in this case, the openings 50 between pairs of adjacent spokes 52 are generally trapezoidal or rectangular, in contrast to the generally triangular shape in the examples of FIGS. 2A - 2D. Also, in the rest state or when no stress is applied, the spokes are configured such that each spoke makes an acute angle with the tangent to the hub.

[0064] Figure 3D shows an enlarged portion of the wheel shown in Figures 3A - 3C. As can be seen at the junction of the spoke and the outer rim 34, at both the circumferentially forward connection point and the circumferentially rearward connection point, there are provided connection portions that are smooth or rounded rather than having sharp angles. The connection portion 50 is curved or rounded rather than being straight and having sharp angles. This is provided to reduce the risk of damage to the wheel during use.

[0065] Since the wheel continuously flexes and extends during use, ultimately, there is a possibility of some damage occurring at the connection between the spoke and the rim 34. By providing smooth or rounded connection points (shown in Figure 3D) between each spoke and the wheel rim 34 (and optionally or alternatively also the hub 32), the risk of damage or breakage is minimized.

[0066] In the example shown in Figures 3A - 3D, the number of spokes has increased compared to Figures 2A - 2D. This is preferable as it increases the portion of the outer surface of the wheel or rim 34 that is actually supported by the material from one of the spokes. In contrast to the example shown in Figures 2A - 2D, the thickness of the spokes has been reduced to facilitate providing more spokes. Also, the general interaction of adjacent spokes is the same as described above with reference to Figures 2A - 2D.

[0067] During use, the wheels are assumed to be sized to be attached to a small vehicle such as a baby carriage or stroller. In particular, the rear wheels and the front wheels will be the same size or, alternatively, the rear wheels will be slightly larger than the front wheels. In one non - limiting example, the rear wheels have a radius of 18 - 24 cm and the front wheels have a radius of 15 - 21 cm. Most preferably, the radius of the rear wheels is 21 cm and the radius of the front wheels is 18 cm. Preferably, the ratio of the radius of the rear wheels to the radius of the front wheels is 7:6. However, it will be understood that these values represent preferred embodiments and are given for illustrative purposes only and are not limiting.

[0068] The structure of the wheel can actually be considered such that the inner hub 32 is suspended from the rim 34 by spokes during normal use. Therefore, at any given time, greater pressure is applied to the lower spokes. However, during normal use, when the wheel rotates during use, the stress is substantially evenly distributed among all the spokes.

[0069] Figure 7A is a schematic view of a further example of a wheel 58 of a stroller. This wheel can be formed in a similar manner and of a similar material as the wheels described above with reference to FIGS. 1 - 6. However, the wheel of this example includes two separate and independent radial regions or annular regions 63 and 65 of spokes.

[0070] The two regions include an outer radial region 63 and an inner radial region 65. They are preferably separated by an intermediate rim 64 which is generally cylindrical. The outer radial region 63 includes a plurality of spokes 66 connecting the outer rim 60 of the wheel to the cylindrical intermediate rim 64. The inner radial region 65 includes a plurality of spokes 68 connecting the hub 62 of the wheel to the cylindrical intermediate rim 64.

[0071] It can be seen that the spokes 66 in the outer radial region 63 are thinner (and thus more flexible assuming a uniform material composition) than the spokes 68 in the inner radial region 65. This wheel operates in a similar manner to the wheels of FIGS. 1 - 6. That is, the wheel has two operating modes, or two suspension modes, that can be provided during use. When subjected to a first level of compressive force, the relatively thinner spokes 66 in the outer radial region deform in response. After reaching the equilibrium position, when a greater force is applied, the relatively thicker spokes 68 in the inner radial region 65 deform in response.

[0072] In this example, the knee described above is effectively replaced by a cylindrical intermediate rim 64. Also, before the spokes in the inner region 65 move or deform at all, contact can occur between adjacent spokes 66 in the radially outer region. However, the bending of the inner spokes is, for example, shown in FIGS. 1-6 and, in contrast to being between a contact point or knee and the hub as in the example described above, is simply between the hub 62 and the cylindrical intermediate rim.

[0073] In one example, two or more intermediate rims are provided, and thus the region between the outer rim and the inner hub is divided into two or more regions for the spokes. For example, as described above, it is also possible to provide two intermediate rims that respectively separate regions within the wheel for spokes of different thicknesses or material compositions.

[0074] FIG. 7B schematically shows such a configuration. In this example, two intermediate rings 641 and 642 are provided. The first intermediate ring 641 is the outer boundary of a first region 70 defined between the hub 62 and the first intermediate ring 641. The second intermediate ring 642 is the outer boundary of a second region 72 defined between the first intermediate ring 641 and the second intermediate ring 642. The third region 72 is defined between the second intermediate ring 642 and the outer rim 60.

[0075] As shown in the figure, spokes 76, 78, and 80 are also schematically provided within each of the regions 70, 72, and 74. Although only one spoke is shown in the drawing, of course, they are provided throughout as in FIG. 7A, and the spokes in each region are the same within that region but different from the spokes in another region. Thus, all the spokes 76 in region 70 are the same, all the spokes 78 in region 72 are the same, and all the spokes 80 in region 74 are the same. However, respectively, the spokes 80 in region 74 are more flexible than the spokes 78 and 76 in regions 72 and 70, and the spokes 78 in region 72 are more flexible than the spokes 76 in region 70.

[0076] Accordingly, when a force is applied to the wheel, the spokes are gradually compressed, thereby providing a multi-stage suspension effect as in the aforementioned example. In the example of FIG. 7B, a three-stage suspension effect is provided. If necessary, additional regions can be provided to achieve any desired number of stages of suspension effect.

[0077] Accordingly, it can be seen that provided is a wheel provided with several (two or more) annular regions each having a plurality of spokes. Preferably, the spokes within each annular region have a different flexibility from the spokes of other annular regions. For example, the plurality of spokes of the entire wheel may include a plurality of radially inner spokes within a first annular region, a plurality of radially intermediate spokes within a second annular region, and a plurality of radially outer spokes within a radially outer region. An intermediate rim is provided between each adjacent annular region.

[0078] Looking at FIG. 7A, it can be understood that the advantage of this configuration is that when the outer spoke 66 reaches maximum compression, the cylindrical intermediate rim 64 acts to further evenly distribute the load to the less flexible spokes 68 of the radially inner region 65. Further, the cylindrical intermediate rim 64 also provides an increase in the lateral stability of the wheel. The corresponding point also applies to the configuration of FIG. 7B in which three annular regions are provided.

[0079] The shape of each individual spoke (e.g., the cross-section of each spoke) can also be the same as that described above with reference to any of FIGS. 1-6. Although it is likely that all the spokes have the same cross-section, in one example, the cross-section of the spokes in one of the annular regions, e.g., the inner region 65 of FIG. 7A, is different from the cross-section of the spokes in the outer region 63 of FIG. 7A.

[0080] Some embodiments of the present invention have been described with particular reference to the illustrated examples. However, it will be understood that variations and modifications may be made to the examples described within the scope of the present invention.

Claims

**Claim 1** A wheel for a small vehicle, comprising: an inner hub for connection to an axle; an outer rim for engagement with the ground during use; a plurality of spokes connected between the inner hub and the outer rim; wherein the spokes are flexible. The wheel. **Claim 2** The wheel according to claim 1, wherein the spokes have a thickness or cross-sectional area that varies along their length. **Claim 3** The wheel according to claim 2, wherein the spokes have a thickness or cross-sectional area that decreases from a radially inner position to a radially outer position. **Claim 4** The wheel according to any one of claims 1 to 3, wherein the spokes have a thickness or cross-sectional area that decreases continuously from a radially inner position at the connection with the inner hub to a radially outer position at the connection with the outer rim, or vice versa. **Claim 5** The wheel according to any one of claims 1 to 4, wherein the spokes are varied in thickness, shape, or material along their length so as to provide a two-stage suspension effect during use. **Claim 6** The wheel according to claim 5, wherein under a first load, the deformation of the spokes occurs in a radially outer region between the rim and the annular shape between the rim and the hub. **Claim 7** The wheel according to claim 6, wherein the annular shape is a circle. **Claim 8** The wheel according to any one of claims 5 to 7, wherein the change in thickness or cross-sectional area is such that when a first force is applied, one or more of the spokes deform to define a knee. **Claim 9** The wheel according to claim 8, wherein the defined knee contacts an adjacent spoke. **Claim 10** The wheel according to claim 9, wherein the change in thickness, shape, material, or cross-sectional area is such that after the defined knee contacts an adjacent spoke, when the force exceeds a defined threshold higher than the force required for the knee to make contact, the remaining portion of the spoke makes contact. **Claim 11** The wheel according to any one of claims 1 to 10, wherein each spoke is connected to the inner hub at one circumferential position and to the outer rim at a different circumferential position such that the spoke is inclined between the inner hub and the outer rim and defines an acute angle with a tangent to the hub or the rim. **Claim 12** The wheel according to any one of claims 1 to 11, wherein a connection between at least one of the spokes and the outer rim is rounded. **Claim 13** The wheel according to any one of claims 1 to 12, wherein a radius is provided at a connection portion between at least one of the spokes and the inner hub.

14. The wheel according to any one of claims 1 to 13, wherein the wheel is a formed wheel.

15. The wheel according to claim 14, wherein the wheel is an integrally formed wheel.

16. The wheel according to any one of claims 1 to 15, wherein the wheel is formed of a composition that is uniformly integrated throughout.

17. The wheel according to any one of claims 1 to 16, wherein the wheel is formed of a composition that varies along the length of the spoke.

18. The wheel according to any one of claims 1 to 17, wherein the diameter of the wheel is 3 to 50 cm, preferably 10 to 40 cm, and most preferably 18 to 28 cm.

19. The wheel according to any one of claims 1 to 18, wherein the plurality of spokes includes a first annular region of spokes that are a plurality of radially inner spokes, a second annular region of spokes that are a plurality of radially outer spokes, and an intermediate rim provided between the first annular region and the second annular region of the spokes.

20. The wheel according to claim 19, further comprising one or more additional annular regions of spokes that are a plurality of radially outer spokes offset radially from the plurality of inner spokes, and corresponding additional intermediate rims.

21. The wheel according to claim 19, wherein the plurality of radially inner spokes are connected between the hub and the intermediate rim, and the plurality of radially outer spokes are connected between the intermediate rim and the outer rim.

22. The wheel according to any one of claims 19 to 21, wherein the plurality of radially outer spokes are more flexible than the plurality of radially inner spokes.

23. A baby stroller having a chassis, a seat, and at least three legs, with wheels provided on each leg to facilitate movement, wherein at least one of the wheels is the wheel according to any one of claims 1 to 22.

24. A small vehicle having one or more wheels to enable rolling or movement on the ground, wherein at least one of the wheels is the wheel according to any one of claims 1 to 22.

25. The vehicle is the small vehicle according to claim 24, which is selected from the group consisting of a golf cart, a wheelchair, a golf trolley, a shopping trolley, a suitcase, a tricycle, or a bicycle.

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