Suspension for wheels

TECHNICAL FIELD

Examples of the present disclosure relate to suspension for wheels. Some examples relate to suspension for bicycle wheels.

BACKGROUND

For aerodynamic purposes, it is increasingly common practice for bicycle wheels to have deeper section rims.

An object of the present disclosure is to take advantage of this trend and utilise the space created by these deeper section wheel rims to provide suspension means comprised within the wheel rims. This provides a discreet, responsive suspension system which is close to the road surface, therefore reducing road shock loads through the wheels and frame at the earliest and most effective stage of road shock input.

Although aspects of the present disclosure are described with reference to wheels for bicycles, it will be appreciated that the invention, as claimed, and the features described herein can be applied to wheels for various other uses.

BRIEF SUMMARY

According to various, but not necessarily all, examples of the present disclosure, there may be provided a wheel comprising: an inner wheel rim for attachment to a wheel hub; and an outer wheel rim, wherein the inner and outer wheel rims comprise sliding surfaces, and wherein the inner and outer wheel rims are configured such that the sliding surfaces: restrain movement of the inner and outer wheel rims relative to one another in directions parallel to the wheel’s rotational axis and enable the inner and outer wheel rims to slide relative to one another in directions perpendicular to the wheel’s rotational axis; the wheel further comprising: suspension means configured to act between the inner wheel rim and the outer wheel rim.

In some, but not necessarily all, examples, the suspension means are configured to be positioned in a space defined between the inner and outer wheel rims. In some, but not necessarily all, examples, the suspension means are configured to produce a bias force, wherein the bias force acts to maintain concentricity of the inner and outer wheel rims.

In some, but not necessarily all, examples, suspension parameters of the suspension means are adjustable when the wheel is in-situ.

In some, but not necessarily all, examples, the suspension means are configured to substantially prevent rotation of the inner and outer wheel rims relative to one another about the wheel’s rotational axis.

In some, but not necessarily all, examples, the suspension means comprise: a plurality of sprung tongs or at least one resiliently deformable element.

In some, but not necessarily all, examples, the resiliently deformable element is an elastomeric tube.

In some, but not necessarily all, examples, the resiliently deformable element is inflatable.

In some, but not necessarily all, examples, the inner wheel rim comprises an aperture for an inflation valve for inflating the resiliently deformable element.

In some, but not necessarily all, examples, the resiliently deformable element is attached to the inner wheel rim to prevent sliding of the resiliently deformable element relative to the inner wheel rim; and/or the resiliently deformable element is attached to the outer wheel rim to prevent sliding of the resiliently deformable element relative to the outer wheel rim.

In some, but not necessarily all, examples, a plunger protrudes from the inner wheel rim or the outer wheel rim, wherein the plunger is configured to deform the resiliently deformable element when the inner and outer wheel rims slide relative to one another in directions perpendicular to the wheel’s rotational axis.

In some, but not necessarily all, examples, an extremity of the plunger has a dimension in a direction of the wheel’s rotational axis that is less than a dimension of the resiliently deformable element in the same direction.

In some, but not necessarily all, examples, the resiliently deformable element is attached to the plunger. In some, but not necessarily all, examples, the sliding surfaces of the inner and outer wheel rims are substantially perpendicular to the wheel’s rotational axis.

In some, but not necessarily all, examples, the inner wheel rim comprises a first sliding surface and a second sliding surface, and the outer wheel rim comprises a first sliding surface and a second sliding surface, wherein the first sliding surface of the inner wheel rim and the first sliding surface of the outer wheel rim are configured to slide in contact while restraining movement of the inner and outer wheel rims relative to one another in a first direction parallel to the wheel’s rotational axis, and wherein the second sliding surface of the inner wheel rim and the second sliding surface of the outerwheel rim are configured to slide in contact while restraining movement of the inner and outerwheel rims relative to one another in a second, opposite, direction parallel to the wheel’s rotational axis.

In some, but not necessarily all, examples, the first and second sliding surfaces of the inner wheel rim are interior-facing surfaces of sides of the inner wheel rim, and the first and second sliding surfaces of the outerwheel rim are exterior-facing surfaces of sides of the outerwheel rim.

In some, but not necessarily all, examples, the first and second sliding surfaces of the inner wheel rim are exterior-facing surfaces of sides of the inner wheel rim, and the first and second sliding surfaces of the outerwheel rim are interior-facing surfaces of sides of the outerwheel rim.

In some, but not necessarily all, examples, at least one of the sliding surfaces comprises one or more grooves.

In some, but not necessarily all, examples, each of the one or more grooves extends in a direction substantially perpendicular to the wheel’s rotational axis.

In some, but not necessarily all, examples, each of the one or more grooves extends in a direction angled relative to the wheel’s radial direction.

In some, but not necessarily all, examples, the outerwheel rim comprises one or more conduits for drainage of a space defined between the inner and outerwheel rims.

In some, but not necessarily all, examples, the outer wheel rim comprises an outer portion and an inner portion, and portions of the sliding surfaces of the outer wheel rim are formed from surfaces of the inner portion of the outerwheel rim.

In some, but not necessarily all, examples, the outer wheel rim is attached to a tyre. In some, but not necessarily all, examples, the inner and outer wheel rims each comprise an aperture for an inflation valve of the attached tyre.

According to various, but not necessarily all, examples of the present disclosure, there may be provided a bicycle comprising one or more wheels as described herein.

According to various, but not necessarily all, examples of the present disclosure, there may be provided examples as claimed in the appended claims.

BRIEF DESCRIPTION

Some example embodiments will now be described with reference to the accompanying drawings in which:

FIG 1 illustrates a cylindrical coordinate system used in this application;

FIG 2 illustrates an example of a wheel from a perspective side view;

FIG 3 illustrates an example of a wheel using an exploded view of a cross-section of the wheel; FIGs 4A, 4B and 4C illustrate cross-sections of an example configuration of a wheel;

FIGs 5A, 5B and 5C illustrate cross-sections of an example configuration of a wheel;

FIG 6 illustrates an example of suspension means;

FIG 7 illustrates a cross-section of an example configuration of a wheel;

FIG 8 illustrates a cross-section of an example configuration of a wheel;

FIG 9 illustrates a cross-section of an example configuration of a wheel;

FIG 10 illustrates a cross-section of an example configuration of a wheel;

FIG 11 illustrates an example of a sliding surface;

FIG 12 illustrates a perspective side view, partially sectioned and enlarged, of a wheel;

FIGs 13A and 13B illustrate an example of a wheel rim;

FIG 14 illustrates an example of a bicycle comprising a frame with two wheels mounted on the frame.

DETAILED DESCRIPTION

The following description relates to a wheel 100 comprising: an inner wheel rim 7 for attachment to a wheel hub 102; and an outer wheel rim 3, wherein the inner and outer wheel rims 7, 3 comprise sliding surfaces 20, and wherein the inner and outer wheel rims 7, 3 are configured such that the sliding surfaces 20: restrain movement of the inner and outer wheel rims 7, 3 relative to one another in directions 112 parallel to the wheel’s rotational axis 110 and enable the inner and outer wheel rims 7, 3 to slide relative to one another in directions 114 perpendicular to the wheel’s rotational axis 110; the wheel 100 further comprising: suspension means 8 configured to act between the inner wheel rim 7 and the outer wheel rim 3.

FIG 1 illustrates a cylindrical coordinate system used throughout this application. FIG 1 shows a basis (r, Q, z) for the cylindrical coordinate system and a set of right-handed Cartesian axes (x, y, z) for reference r is the radial vector and is parallel to the x-y plane. Q is the angle of r from the positive x axis z is the axial vector, it is orthogonal to r.

FIG 2 shows an example of a wheel 100 from a perspective side view. The wheel 100 is defined with respect to the cylindrical coordinate system such that an origin of the cylindrical coordinate system origin, O, is positioned at a centre of a wheel hub 102 of the wheel 100 and such that the wheel’s rotational axis 110 is aligned with the z-axis. The wheel’s plane of rotation, meaning the plane perpendicular to the wheel’s rotational axis 110, is therefore the x-y plane (i.e. the plane of the page).

As used herein, the term ‘lateral’ refers to directions 112 (not illustrated) parallel to the wheel’s rotational axis 110 and the term ‘radial’ refers to directions 114 parallel to the x-y plane and originating from the wheel’s rotational axis 110 (i.e. parallel to the vector r). The term ‘inner’ refers to a component that is closer to the rotational axis 110 in a radial direction 114 compared to an ‘outer’ component.

FIG 2 shows an example where the wheel 100 is substantially circular when viewed from the side (i.e. when viewed along the wheel ‘s rotational axis 110). In other examples, the wheel 100 may have a different shape when viewed from the side, particularly when it is under load. For example, the wheel 100 may be substantially elliptical when viewed from the side.

In the example shown in FIG 2, the wheel 100 comprises a wheel hub 102. The axis of the wheel hub 102 is substantially aligned with the wheel ‘s rotational axis 110. In some examples, the wheel hub 102 may be configured to attach the wheel 100 to a wheeled apparatus, such as a bicycle 200 (see FIG 14). For example, the wheel hub 102 may be configured for attachment to an axle of the wheeled apparatus.

The wheel 100 may comprise a plurality of wheel rims 3, 7. In the example shown in FIG 2, the wheel 100 comprises an inner wheel rim 7 and an outer wheel rim 3. When viewed from the side (i.e. when viewed along the wheel ‘s rotational axis 110), the inner wheel rim 7 and the outer wheel rim 3 may be substantially circular. In other examples, the inner and/or outer wheel rims 7, 3 may have a different shape when viewed from the side, particularly when the wheel 100 is under load. For example, the shape may be substantially elliptical when viewed from the side.

In the example of FIG 2, the inner wheel rim 7 is configured for attachment to the wheel hub 102. The inner wheel rim 7 may be attached to the wheel hub 102 via wheel hub attachment means 103; for example, spokes. In the example of FIG 2, the inner wheel rim 7 is attached to the wheel hub 102 via three spokes 103. In other examples, there may be a greater number of spokes or a lesser number of spokes.

In some examples, the wheel hub attachment means 103 and the inner wheel rim 7 may be separate components and they may be configured to be connected together. In other examples, the wheel hub attachment means 103 and the inner wheel rim 7 may be one and the same component; that is integral components.

In some example embodiments, the outer wheel rim 3 may be configured for attachment to a tyre 1. For example, the outer wheel rim 3 may be a ‘clincher’ rim or a ‘tubular’ rim or a ‘tubeless’ rim. In other example embodiments, the outer wheel rim 3 may itself be configured for contact with the ground without the need for a tyre 1.

FIG 3 illustrates an example of a wheel 100 using an exploded view of a cross-section of the wheel 100 such that the individual component parts are separately illustrated. The exploded view of FIG 3 is illustrative of section A-A from FIG 2. In some examples, the cross-sections of the components shown in FIG 3 may extend for the full circumference of the wheel 100 or for substantially the full circumference of the wheel 100. In some examples, the cross-section of one or more of the components shown in FIG 3 may not extend for the full circumference of the wheel 100

In FIG 3 the plane of the page is the x-z plane and the y-axis is perpendicular to the plane of the page.

The wheel 100 comprises: an inner wheel rim 7 for attachment to a wheel hub 102; an outer wheel rim 3; and suspension means 8 configured to act between the inner wheel rim 7 and the outer wheel rim 3.

The inner wheel rim 7 comprises a central portion 70 and two opposing side wall portions 72A, 72B with an interior space 18 between them. Each side wall portion 72A, 72B comprises a respective interior-facing surface 74A, 74B and a respective exterior-facing surface 76A, 76B. The central portion 70 comprises an interior-facing surface 79 and an exterior-facing surface 77. The exterior-facing surface 77 is configured for attachment to a wheel hub 102 (not illustrated), for example, via wheel hub attachment means 103 (not illustrated). In some examples, the interior-facing surface 79 of the central portion 70 is configured for attachment to the suspension means 8.

The outer wheel rim 3 comprises a central portion 30 and two opposing side wall portions 32A, 32B with an interior space 18 between them. Each side wall portion 32A, 32B comprises a respective interior-facing surface 34A, 34B and a respective exterior-facing surface 36A, 36B. The central portion 30 comprises an interior-facing surface 39 and an exterior-facing surface 37. In some examples, the exterior-facing surface 37 is configured for attachment to a tyre 1 (not illustrated). In some examples, the interior-facing surface 79 is configured for attachment to the suspension means 8.

The inner and outer wheel rims 7, 3, when assembled, are configured for relative sliding motion. The interior-facing surfaces 74A, 74B; 34A, 34B of one of the wheel rims 7, 3 provide sliding surfaces 20 that slide over exterior-facing surfaces 36A, 36B; 76A, 76B of one of the other of the wheel rims 3, 7.

For example, in an implementation, illustrated in FIGs 4A, 4B and 4C, the interior-facing surfaces 74A, 74B of the inner wheel rim 7 provide sliding surfaces 20A and the exterior-facing surfaces 36A, 36B of the outer wheel rim 3 provide sliding surfaces 20B.

For example, in a different implementation, illustrated in FIGs 5A, 5B and 5C, the exterior-facing surfaces 76A, 76B of the inner wheel rim 7 provide sliding surfaces 20B and the interior-facing surfaces 34A, 34B of the outer wheel rim 3 provide sliding surfaces 20A.

The inner and outer wheel rims 7, 3 are configured in the assembled wheel 100 such that the sliding surfaces 20: restrain movement of the inner and outer wheel rims 7, 3 relative to one another in directions 112 parallel to the wheel’s rotational axis 110 (i.e. z-direction) and enable the inner and outer wheel rims 7, 3 to slide relative to one another in directions 114 perpendicular to the wheel’s rotational axis 110 (i.e. x-y plane).

In the examples illustrated the sliding surfaces 20 are sufficiently smooth to enable sliding of the inner and outer wheel rims 7, 3 relative to one another in directions 114 perpendicular to the wheel’s rotational axis 110. The sliding surfaces 20 are sufficiently smooth to allow the inner and outer wheel rims 7, 3 to move smoothly along one another while maintaining continuous contact. In the examples illustrated the side wall portions 72, 32 of the inner and outer wheel rims 7, 3 are sufficiently strong and stiff to restrain movement of the inner and outer wheel rims 7, 3 relative to one another in directions 112 parallel to the wheel’s rotational axis 110 (i.e. z-direction). Restraining movement in directions 112 parallel to the wheel’s rotational axis 110 reduces or prevents lateral misalignment of the wheel rims.

In the illustrated examples, the sliding surfaces 20 of the inner and outer wheel rims 7, 3 are substantially perpendicular to the wheel’s rotational axis 110.

The outer wheel rim 3 may be configured to fit inside the inner wheel rim 7 and the inner wheel rim 7 configured to fit outside the outer wheel rim 3 (as shown in FIG 4A, 4B, 4C) such that first and second sliding surfaces 20 of the inner wheel rim 7 are interior-facing surfaces 74A, 74B of side wall portions 72A, 72B of the inner wheel rim 7, and first and second sliding surfaces 20 of the outer wheel rim 3 are exterior-facing surfaces 36A, 36B of side wall portions 32A, 32B of the outer wheel rim 3. The inner wheel rim 7 comprises a first sliding surface (surface 74A) and a second sliding surface (surface 74B), and the outer wheel rim 3 comprises a first sliding surface (surface 36A) and a second sliding surface (surface 36B). The first sliding surface (surface 74A) of the inner wheel rim 7 and the first sliding surface (surface 36A) of the outer wheel rim 3 are configured to slide in contact while restraining movement of the inner and outer wheel rims 7, 3 relative to one another in a first direction (e.g. -z) 112 parallel to the wheel’s rotational axis 110, and the second sliding surface (surface 74B) of the inner wheel rim 7 and the second sliding surface (surface 36B) of the outer wheel rim 3 are configured to slide in contact while restraining movement of the inner and outer wheel rims 7, 3 relative to one another in a second, opposite, direction (e.g. +z) 112 parallel to the wheel’s rotational axis 110.

The outer wheel rim 3 may be configured to fit outside the inner wheel rim 7 and the inner wheel rim 7 configured to fit inside the outer wheel rim 3 (as shown in FIG 5A, 5B, 5C) such that first and second sliding surfaces 20 of the inner wheel rim 7 are exterior-facing surfaces 76A, 76B of side wall portions 72A, 72B of the inner wheel rim 7, and first and second sliding surfaces 20 of the outer wheel rim 3 are interior-facing surfaces 34A, 34B of side wall portions 32A, 32B of the outer wheel rim 3. The inner wheel rim 7 comprises a first sliding surface (surface 76A) and a second sliding surface (surface 76B), and the outer wheel rim 3 comprises a first sliding surface (surface 34A) and a second sliding surface (surface 34B). The first sliding surface (surface 76A) of the inner wheel rim 7 and the first sliding surface (surface 34A) of the outer wheel rim 3 are configured to slide in contact while restraining movement of the inner and outer wheel rims 7, 3 relative to one another in a first direction (e.g. +z) 112 parallel to the wheel’s rotational axis 110, and the second sliding surface (surface 76B) of the inner wheel rim 7 and the second sliding surface (surface 34B) of the outer wheel rim 3 are configured to slide in contact while restraining movement of the inner and outer wheel rims 7, 3 relative to one another in a second, opposite, direction (e.g. -z) 112 parallel to the wheel’s rotational axis 110.

The suspension means 8 are configured to act between the inner wheel rim 7 and outer wheel rim 3. In some examples, an outer portion of the suspension means 8 may be configured for attachment to the outer wheel rim 3. In some examples, an inner portion of the suspension means 8 may be configured for attachment to the inner wheel rim 7.

From the foregoing, it can be understood that the outer wheel rim 3 is slidingly engaged radially and restrained laterally with the inner wheel rim 7 which can be mounted to the central wheel hub 102. The two wheel rims 7, 3 are held apart and centralised radially by the suspension means 8 which can provide a controlled preload and suspension method, allowing the outer wheel rim 3 to slide, in dependence on the load, relative to the inner rim 7 by acting against the suspension means 8 when a road shock input is present and returning the outer wheel rim 3 to its centralised position when under normal load.

The inner and outer wheel rims 7, 3 are configured to fit together such that a space 18 is defined between the inner and outer wheel rims 7, 3. The suspension means 8 are configured to be positioned in the space 18 defined between the inner and outer wheel rims 7, 3.

The suspension means 8 are configured to provide good shock absorption and enable good grip between the wheel 100 and the ground. The suspension means 8 act to reduce transmission, to the inner wheel rim 7, of external forces acting on the outer wheel rim 3; therefore, providing good shock absorption. The suspension means 8 act to maintain a substantially constant magnitude of normal force between the wheel 100 and the ground; therefore, enabling good grip.

The suspension means 8 are configured to produce a bias force 40, wherein the bias force 40 acts to maintain concentricity of the inner and outer wheel rims 7, 3.

As illustrated in FIG 4B and 5B, when the inner and outer wheel rims 7, 3 move away from one another (i.e. when the wheel rims 7, 3 are not in a neutral position, as shown in FIGs 4A and FIG 5A), the suspension means 8 are configured to provide a bias force 40 that acts against further movement of the inner and outer wheel rims 7, 3 away from one another and acts to return the inner and outer wheel rims 7, 3 to a neutral position, as shown in FIGs 4A and 5A.

As illustrated in FIG 4C and 5C, when the inner and outer wheel rims 7, 3 move towards one another (i.e. when the wheel rims 7, 3 are not in a neutral position, as shown in FIGs 4A and 5A), the suspension means 8 are configured to provide a bias force 40 that acts against further movement of the inner and outer wheel rims 7, 3 towards one another and acts to return the inner and outer wheel rims 7, 3 to a neutral position, as shown in FIGs 4A and 5A.

The suspension means 8 are configured to maintain at least some overlap of the sliding surfaces 20 of the inner and outer wheel rims 7, 3 during normal suspension operation.

The suspension means 8 may comprise at least one of: a component which produces a bias force 40 which is a function of the displacement across the component; and/or a component which produces a bias force 40 which is a function of the velocity across the component; and/or a component which produces a bias force 40 which is a function of the acceleration across the component.

A component which produces a bias force 40 which is a function of the displacement across the component is commonly referred to as a spring. The function which defines the relationship between the bias force 40 produced by the component and the displacement across the component may be a constant (i.e. a linear spring) or it may not be a constant (i.e. a non-linear spring).

A component which produces a bias force 40 which is a function of the velocity across the component is commonly referred to as a dashpot, sometimes as a damper. The function which defines the relationship between the bias force 40 produced by the component and the velocity across the component may be a constant (i.e. a linear damper) or it may not be a constant (i.e. a non-linear damper).

A component which produces a bias force 40 which is a function of the acceleration across the component is commonly referred to as an inerter. The function which defines the relationship between the bias force 40 produced by the component and the acceleration across the component may be a constant (i.e. a linear inerter) or it may not be a constant (i.e. a non-linear inerter).

The suspension means 8 may be adjustable to control the magnitude of the bias force and/or the response of the bias force to displacement/velocity/acceleration. In some examples, suspension parameters of the suspension means 8 may be adjustable when the wheel 100 is in-situ; that is to say, suspension parameters of the suspension means 8 may be adjustable while the wheel 100 is attached to a wheeled apparatus. The suspension means 8 may be configured such that their contribution to the moment of inertia of the wheel 100 is lessened (e.g. by positioning mass closer to the centre of the wheel 100).

When a driving or braking torque is applied to the wheel 100 there may be a tendency for the inner and outer wheel rims 7, 3 to rotate relative to one another about the wheel’s rotational axis 110. As disclosed below, the suspension means 8 can be configured to substantially prevent rotation of the inner and outer wheel rims 7, 3 relative to one another about the wheel’s rotational axis 110.

FIG 6 shows an example where the suspension means 8 comprise a plurality of springs configured as sprung tongs 60. The sprung tongs extend between and are connected to the inner wheel rim 7 and the outer wheel rim 3. In this example, the sprung tongs form an acute angle a to the inner wheel rim 7 and have a neutral position where they form an acute angle a ₀ to the inner wheel rim 7. The resilient bias of the sprung tongs 60 attempts to return the angle a to angle cr _0. Therefore, the sprung tongs 60 can be configured to substantially prevent excessive rotation, about the wheel’s rotational axis 110, of the inner and outer wheel rims 7, 3 relative to one another.

The suspension means 8 may comprise at least one resiliently deformable element 50. FIGs 7, 8, 9 and 10 are cross-sections illustrating examples of a wheel 100, in accordance with the present disclosure. In these examples the suspension means 8 comprise a resiliently deformable element 50. In the examples of FIGs 7, 8 and 9, the outer wheel rim 3 travels within and in sliding contact with the inner wheel rim 7 as described in FIGs 4A, 4B and 4C. In the examples of FIG 10 the inner wheel rim 7 travels within and in sliding contact the outer wheel rim 3 as described in FIGs 5A, 5B and 5C.

In the examples shown in FIGs 7-10, but not necessarily all examples, a plunger 4 is configured to deform the resiliently deformable element 50 when the inner and outer wheel rims 7, 3 slide relative to one another in directions 114 perpendicular to the wheel’s rotational axis 110. The resiliently deformable element 50 is resiliently compressed when outer wheel rim 3 and the inner wheel rim 7 move towards each other from a neutral position. The resiliently deformable element 50 is resiliently tensioned when the outer wheel rim 3 and the inner wheel rim 7 move away from each other from a neutral position.

In the examples shown in FIGs 7-10, an extremity 14 of the plunger 4 has a dimension in a direction of the wheel’s rotational axis 110 (i.e. z-direction) that is less than a dimension of the resiliently deformable element 50 in the same direction. The cross-sectional shape of the resiliently deformable element 50 may be any suitable shape. The resiliently deformable element 50 may be adjustable to control the bias force 40 (not illustrated) generated.

In some examples, the resiliently deformable element 50 may be solid or voided. To say that the resiliently deformable element 50 is voided means that it contains one or more cavities. A specific example of a voided element is a hollow element (i.e. a tube) which contains a single, central cavity running the entire length of the element. To say that the resiliently deformable element 50 is solid means that it contains substantially no cavities.

In the examples illustrated in FIGs 7-10, the resiliently deformable element 50 comprises an elastomeric tube 52.

In the examples of FIGs 7-10, but not necessarily all examples, the elastomeric tube 52 has a substantially circular cross-section. In these examples, but not necessarily all examples, the elastomeric tube 52 is an air-tight, inflatable/pneumatic elastomeric tube 52. The extent of inflation of the elastomeric tube 52 can be used to control the bias force 40 generated.

The resiliently deformable element 50 may be a solid or voided elastomeric material, reinforced or unreinforced. In the examples illustrated, but not necessarily all examples, the resiliently deformable element 50 is a thin-walled elastomeric tube 52 reinforced with suitable high strength and flexible reinforcing fibres. The reinforcing fibres may be conveniently incorporated into the elastomeric tube 52 by using a diagonally woven tube or a fabric, wrapped and over-moulded, to increase surface friction. The fibres and elastomeric tube 52 provide a radially compressible and substantially inextensible airtight tube, sealed at each end, fitted circumferentially into the inner rim 7 and incorporating a valve 11 (shown in FIG 7) allowing the elastomeric tube 52 to be pressurized. The inner wheel rim 7 comprises an aperture 12 for an inflation valve 11 for inflating the elastomeric tube 52.

The contact between the plunger 4 and the resiliently deformable element 50 as applied around the circumference of the wheel 100, can be varied by design to create a preload force which centralises the outer wheel rim 3 relative to the inner wheel rim 7. It will be appreciated that in the case of a pneumatic elastomeric tube 52 the centralising force can be readily adjusted by varying the pressure using valve 11 to create a centralising preload. In examples where the wheel 100 is attached to a bicycle 200, it will also be appreciated that this centralising preload force is the force which supports the weight of the rider and bicycle 200 but allows suspension travel at higher loads such as road vibration and shock. In the particular examples shown, but not necessarily all examples, a first portion of the resiliently deformable element 50 is attached to a respective wheel rim and a second portion of the resiliently deformable element 50 is attached to the plunger 4. In FIGs 7, 8 and 10, an inner portion of the resiliently deformable element 50 is attached to the inner wheel rim 7 and an outer portion of the resiliently deformable element 50 is attached to the plunger 4. In FIG 9, an inner portion of the resiliently deformable element 50 is attached to the plunger 4 and an outer portion of the resiliently deformable element 50 is attached to the outer wheel rim 3.

In some examples, which are not shown, the wheel 100 may not comprise a plunger 4. In such examples, an inner portion of the resiliently deformable element 50 may be attached to the inner wheel rim 7 and an outer portion of the resiliently deformable element 50 may be attached to the outer wheel rim 3.

Attachment of the resiliently deformable element 50 to the respective wheel rim(s) and/or to the plunger 4 may, for example, be made by bonding, adhesive bonding, laser welding, ultrasonic welding. In some examples, the attachment is configured to prevent sliding of the resiliently deformable element 50 relative to the respective wheel rim(s) and/or relative to the plunger 4. In the examples where the wheel 100 comprises a plunger 4, the resiliently deformable element 50 is configured to maintain contact with the plunger 4 throughout normal suspension operation.

It will be appreciated from FIG 7-10 that the plunger 4 and the resiliently deformable element 50 move relative to each other in dependence upon movement of the inner and outer wheel rims 7, 3. In FIGs 7, 8 and 10, the plunger 4 (not the resiliently deformable element 50) moves with the outer wheel rim 3. The inner form of the inner wheel rim 7 is shaped to provide a seat to accommodate the resiliently deformable element 50. In FIG 9 the resiliently deformable element 50 (not the plunger 4) moves with the outer wheel rim 3.

The resiliently deformable element 50, seated in a wheel rim 7, 3, can lie circumferentially within a space 18 defined by that rim. The resiliently deformable element 50 can be in contact, for example permanent contact, in a parallel circumferential manner with the opposing plunger 4.

Thus, the resiliently deformable element 50 can be seated in the inner wheel rim 7 (FIGs 7, 8 and 10) and lie circumferentially within a space 18 defined by the inner rim. The resiliently deformable element 50 can be in contact, for example permanent contact, in a parallel circumferential manner with the opposing plunger 4 and hence outer wheel rim 3.

In the examples of FIGs 7-9, the outer wheel rim 3 travels within and in sliding contact with the inner wheel rim 7 as described in FIGs 4A, 4B and 4C.The side wall portions 32 of the outer wheel rim 3 are parallel and suitably finished to provide exterior-facing surfaces 36 as radially extending sliding surfaces 20 (radial sliding surfaces 20). The side wall portions 72 of the inner wheel rim 7 are parallel and suitably finished to provide interior-facing surfaces 74 as radially extending sliding surfaces 20 (radial sliding surfaces). The radial sliding surfaces 20 of the outer wheel rim 3 are engaged with the parallel radial sliding surfaces 20 of the inner when rim 7. The sliding surfaces 20 of the outer rim 3 and sliding surfaces 20 of the inner rim 7 extend for the full circumference of the respective rim. The plunger 4 may be a separate component.

The inner wheel rim 7 is externally profiled in such a way that it can accommodate the finished sliding surfaces 20 and radial travel of the outer rim 3 while approximately maintaining the preferred aerodynamic profile on its exterior surface.

In the examples of FIGs 7-9, the outer wheel rim 3 comprises an outer portion 31 and an inner portion 33. The inner and outer portions 31, 33 of the outer wheel rim 3 may be formed separately as components. Attachment of the inner and outer portions 31, 33 of the outer wheel rim 3 to one another may, for example, be made by bonding, adhesive bonding, laser welding, ultrasonic welding.

Forming the inner and outer portions 31, 33 of the outer wheel rim 3 separately may make manufacture and/or assembly better; for example, the separate components can be specifically designed and manufactured such that their structural and material properties are better suited to their functions and/or such that components of the wheel 100 can be more easily assembled.

In the examples illustrated in FIGs 7-9, the outer portion 31 of the outer wheel rim 3 is attached to a tyre 1 ; however, in other examples this may not be the case.

In the examples of FIGs 7 and 8, the inner portion 33 of the outer wheel rim 3 comprises the plunger 4. The plunger 4 protrudes from the outer wheel rim 3. The plunger protrudes inwards from the outer wheel rim 3 in a substantially radial direction into the space 18 defined by the inner wheel rim 7.

In the example illustrated in FIG 7, the sliding surfaces 20 of the outer wheel rim 3 are formed entirely from surfaces of the outer portion 31 of the outer wheel rim 3.

In the example illustrated in FIG 8, the sliding surfaces 20 of the outer wheel rim 3 are formed, at least partially, from surfaces of the inner portion 33 of the outer wheel rim 3. In this example, the inner portion 33 of the outer wheel rim 3 therefore provides the plunger 4 and, at least partially, provides the sliding surfaces 20. A retaining ridge or indent in the inner portion 33 (or outer portion 31) can be used to engage with a matching feature in the outer portion 31 (or inner portion 33).

In the example illustrated in FIG 9, the sliding surfaces 20 of the outer wheel rim 3 are formed entirely from surfaces of the inner portion 33 of the outer wheel rim 3.

In FIG 9, the resiliently deformable element 50 (not the plunger 4) moves with the outer wheel rim 3. The inner wheel rim 7 comprises the plunger 4. The plunger 4 protrudes from the inner wheel rim 7. The plunger protrudes outwards from the inner wheel rim 7 in a substantially radial direction into the space 18 defined by the inner wheel rim 7.

In this example, the plunger 4 is integral with the inner wheel rim 7. The plunger 4 can act to reinforce the stiffness of the inner wheel rim 7 in the spoke loading area/region.

In some examples, the inner wheel rim 7 may comprise one or more seals 90 to prevent the ingress of dirt and/or liquid into the space 18 defined between the inner and outer wheel rims 7, 3.

FIG 10 illustrates an example of a cross-section of a wheel 100, in accordance with the present disclosure.

This example illustrates that the outer wheel rim 3 may, in some examples, be a single unitary component. In this example, the plunger 4 is an integral component of the outer wheel rim 3.

This example illustrates that the outer wheel rim 3 may, in some examples, comprise one or more conduits 80 for drainage of the space 18 defined between the inner and outer wheel rims 7, 3. In the example illustrated in FIG 10, the portion of the outer wheel rim 3 shown in cross-section comprises two conduits 80. In other examples, the portion of the outerwheel rim 3 shown in cross- section may comprise a greater or a lesser number of conduits 80.

The conduits 80 act to drain the space 18 defined between the inner and outer wheel rims 7, 3. For example, they can provide a conduit for centrifugal expulsion of liquid from the space 18 and/or for the draining of liquid under gravity.

It will be appreciated that the conduits 80 do not extend around the entire circumference of the outer wheel rim 3, rather the outer wheel rim 3 may comprise a discrete number of conduits 80 that are separate from one another and spaced around the circumference of the outerwheel rim 3. In the example illustrated in FIG 10, the outer wheel rim 3 is attached to a tyre 1; however, in other examples this may not be the case.

FIG 11 illustrates an example of a sliding surface 20. A sliding surface preferably has low friction and wear resistant properties.

Friction can be reduced by a suitable choice of material. For example, a sliding surface 20 can be formed from or coated with steel, aluminium, acetal plastic, nylon, glass, aramid. For example, the sliding surface can have a coating formed by chrome, anodising, graphite, basalt, PTFE.

Friction can be reduced by reducing the contact area between sliding surfaces. This can be achieved, for example, by at least one of the contacting sliding surfaces 20 comprising one or more grooves 62. FIG 11 illustrates an example of a sliding surface 20 comprising a plurality of grooves 62.

In this example, each of the grooves 62 extends in a direction substantially perpendicular 114 to the wheel’s rotational axis 110. In some examples, the grooves 62 may extend substantially radially. In some examples, each of the grooves 62 may extend in a direction angled relative to the wheel’s radial direction.

The grooves 62 may act to drain the space 18 defined between the inner and outer wheel rims 7, 3. For example, they can provide a conduit for centrifugal expulsion of liquid from the space 18 and/or for the draining of liquid under gravity.

FIG 12 shows an example of a perspective side view, partially sectioned and enlarged, of the inner and outer wheel rims 7, 3. As shown in this example, the plunger 4 and resiliently deformable element 50 do not extend around the full circumference of the wheel 100. This provides a gap adjacent to the tyre inner tube inflation valve 9, sufficient to allow the valve 9 of a road tyre 1, attached to the outer wheel rim 3, to pass through an aperture 15 in the outer wheel rim 3 and an aperture 16 in the inner wheel rim 7 and protrude out of the inner wheel rim 7 to facilitate inflation of the road tyre 1 when attached to the outer wheel rim 3. Long valves as described with a smooth outer surface are readily available and known practice for use with current deep rims; such valves may, for example, have a flexible stem. The tyre inner tube inflation valve 9 is free to slide through the aperture 16 in the inner rim 7 to accommodate suspension movement of the inner and outer wheel rims 7, 3. In some examples, the tyre inner tube inflation valve 9 is guided by a bush 10 located in the aperture 16 in the innerwheel rim 7 which may also locate and restrain the ends of the resiliently deformable element 50. It will be appreciated that the ends of the resiliently deformable element 50 adjacent to the bush 10 are, preferably, sealed in an air-tight manner and protected from abrasion and/or pinching.

In some examples, the root of the tyre inner tube inflation valve 9 (i.e. the portion of the valve 9 adjacent to the connection with the tyre inner tube) may be restrained such that a portion of the valve 9 adjacent to the tyre inner tube is substantially prevented from moving relative to the aperture 15 in the outer wheel rim 3.

In other examples (not shown), the plunger 4 and resiliently deformable element 50 may extend around the full circumference of the wheel 100; however, the plunger 4 and resiliently deformable element 50 may each comprise an aperture for a tyre inner tube inflation valve 9 of an attached tyre 1 as described above.

As mentioned above, in some examples, it is desirable that rotation of the elements of the wheel 100 relative to one another about the wheel’s rotational axis 110, for example, due to suspension, drive or braking forces, is avoided. This aims to enable efficient transmission of drive and braking forces between the inner and outer wheel rims 7, 3 and aims to prevent undesirable excessive misalignment of the tyre inner tube valve 9 relative to bush 10 or the aperture 16 in the inner wheel rim 7 when a tyre 1 is attached to the outer wheel rim 3.

The aforementioned preload and attention to the friction levels of the attachment of the resiliently deformable element 50 to the respective wheel rim(s) and/or to the plunger 4 is a factor in preventing rotation and may be increased by known methods such as adhesive bonding, friction modifying textures, forms or finishes. For example, by incorporating an angled or diagonal weave into the fibre reinforcement of the resiliently deformable element 50, these reinforcing fibres will also resist rotational forces between the components. Said rotation can also be prevented by ensuring that the attachment of the resiliently deformable element 50 to the respective wheel rim(s) and/or to the plunger 4 has a sufficiently high shear strength to prevent sliding between said elements. Additionally, the resiliently deformable element 50 may be configured such that its shear modulus is sufficiently high that it substantially prevents relative movement between the inner and outer wheel rims 7, 3 in directions that are not substantially radial, thereby resisting rotation of the inner and outer wheel rims 7, 3 relative to one another about the wheel’s rotational axis 110.

In some examples, it may be desirable that any relative movement between the inner and outer wheel rims 7, 3, as a result of contact with the ground, is substantially restricted to the portion of the wheel 100 below the wheel’s horizontal centre line. That is to say, the wheel 100 may be configured such that substantial movement of the inner and outer wheel rims 7, 3 relative to one another only occurs in the lower half of the wheel 100 (i.e. relative movement between the inner and outer wheel rims 7, 3 is substantially contained to the portion of the wheel 100 proximal to the point of contact with the ground and the centres of the inner and outer wheel rims 7, 3 remain in substantially the same location during relative movement of the wheel rime 7, 3). This may, for example, be achieved by designing the outer wheel rim 3 such that it has a reduced stiffness, meaning it deflects to a greater extent in response input forces.

An example of such a design is illustrated in FIG 13A which shows how the inner portion 33 of the outer wheel rim 3 may be sectioned appropriately such that its bending stiffness is reduced. In the example shown, the inner portion 33 of the outer wheel rim 3 has been sectioned by removing material in a direction substantially parallel 112 to the wheel’s axis of rotation 110. Sectioning a component in this way may be described as castellation. FIG 13B illustrates section B-B from FIG 13A and shows an example of how the inner portion 33 of the outer wheel rim 3 may be designed so as to enable easier assembly of the wheel 100. In the example shown, the lateral portions of the component are, in essence, hinged to the central portion, meaning the component can be more easily contracted, for example, when being fitted inside the inner wheel rim 7.

In some examples, it may be desirable that relative movement between the inner and outer wheel rims 7, 3, as a result of contact with the ground, is enabled around the entire circumference of the wheel 100. That is to say, the wheel 100 may be configured such the inner and outer wheel rims 7, 3 can move out of substantial concentricity with each other meaning the centres of the inner and outer wheel rims 7, 3 do not remain in substantially the same location during relative movement of the wheel rime 7, 3. This may, for example, be achieved by configuring the resiliently deformable element 50 such that its shear modulus is sufficiently low that it enables relative movement between the inner and outer wheel rims 7, 3 in directions that are not substantially radial. It will be appreciated that, in such examples, the inner and outer wheel rims 7, 3 should remain engaged at all points during normal suspension operation. This may also be achieved by incorporating a longitudinal weave into the fibre reinforcement of the resiliently deformable element 50.

FIG 14 shows a bicycle 200 comprising a frame with two wheels 100 mounted on the frame. In FIG 14, both of the wheels 100 mounted on the frame are as previously described. In other examples, not shown, only one of the wheels 100 mounted on the frame may be as previously described.

Conventional suspensions can suffer increased friction or even binding under non-vertical braking loads or severe pothole ‘climb out’ situations. The present disclosure substantially avoids or ameliorates these problems by providing suspension travel in response to any load presentation angle around the circumference of the wheel 100. This is enabled because the planes of the sliding surfaces 20 are parallel to and aligned with the force input plane for any load presentation angle. The suspension system will therefore continue to operate effectively under braking or pothole conditions with clear benefits in ride and handling.

It will also be appreciated that the present disclosure inherently reduces the unsprung mass of the system. By absorbing road vibration and shock at the earliest and most effective stage, the present disclosure provides increased protection for components of the wheel 100 such as the spokes 103 which are conventionally unsprung and therefore conventionally subjected to near peak shock loads. By reducing the transmittal of shock loads through such components, the present disclosure allows the possibility for redesign in pursuit of additional benefits such as reduced mass, improved aerodynamics and reduced cost.

By utilising aspects of the present disclosure, it may be possible to partially or entirely remove conventional suspension components; therefore, leading to benefits such as significantly more design freedom, reduced cost and reduced mass.

Furthermore, a range of rider and bicycle 200 weights and also road surfaces can be catered for with a simple adjustment of the suspension means 8, for example, by inflation/deflation of an inflatable elastomeric tube.

The preceding examples disclose a wheel 100 mounted suspension system comprising two concentric wheel rims, i.e. an inner rim 7 attached to a central hub 102 and axle by known methods such as spokes 103 and with an outer rim 3 slidingly engaged radially with the inner rim 7 and restrained laterally by the circumferential parallel surfaces 20 of the inner and outer rims 7, 3 and free to move radially.

In at least some examples, the inner and outer rims 7, 3 are separated by an elastomeric element 50 providing both a centralising preload force to the outer rim 3 relative to the inner rim 7 and also a suspension method.

In at least some examples, a plunger 4 form engaging with the elastomeric element 50 may be integrated into the outer rim 3.

In at least some examples, a plunger 4 form engaging with the elastomeric element 50 may be integrated into the inner rim 7. In at least some examples, the plunger 4 form may be a separate element.

In at least some examples, the plunger 4 form may be a separate element extending into the sliding area 18 between the outer and inner rim 3, 7 attached to the outer rim 3 and providing a bearing surface 20 between both rims 3, 7.

In at least some examples, the elastomeric element 50 may be of a suitably shaped solid or voided elastomeric material with or without reinforcing fibres allowing compression and therefore controlled suspension movement of the outer rim 3 relative to the inner rim 7.

In at least some examples, the elastomeric element 50 is a flexible reinforced airtight tube 52 which can conveniently be pressurized as required to adjust load and shock absorbing properties and is reinforced in such a manner that rotational forces are effectively resisted.

In at least some examples, road deflection of the outer rim 3 is substantially and by design limited to the sector of the wheel 100 below the horizontal centre line due to the restriction of relative rotation of the two rims 3, 7.

In at least some examples, the road shock is significantly absorbed within the tyre 1 and rim assembly 3, 7 of the machine resulting in minimal un-sprung mass and hysteresis with consequent benefits in reducing transmission of road shock and vibration into the rest of the wheel 100, machine frame and rider.

In at least some examples, the suspension system is capable of fitment to front and or rear of most types of bicycle 200 and with minimal or little modification or adaptation including as an aftermarket fitment.

In at least some examples, the suspension system will contribute to and enhance other suspension or ride improving features when used concurrently with them.

In at least some examples, the suspension system adds little to the bicycle 200 weight particularly when compared with other known mechanical suspension systems and aerodynamic rims.

In at least some examples, the elastomeric element 50 and plunger 4 are not fully circumferential allowing a route for the tyre inflation valve 11 used to control pressure in the road tyre to pass through the assembly and inner rim for maintenance access. In at least some examples, bonding, surface friction modifying textures, forms or finishes of the elements may be used to prevent rotation of both rims 3, 7, the plunger 4 and the elastomeric element 50 relative to each other.

In at least some examples a bicycle suspension system can be incorporated into the periphery of the wheel 100 adjacent to the tyre using two rims 3, 7, one, carrying the tyre 1 , slidingly located in the other with an resiliently deformable element 50 between the two providing a centralising preload force and also suspension means 8.

Although examples of the present disclosure have been described in the preceding paragraphs, it should be appreciated that modifications to the given examples can be made without departing from the scope of the invention as claimed.

For example, although examples of the present disclosure have been described with reference to wheels for bicycles, it should be appreciated that the invention, as claimed, and the features described above may be applied to wheels for various other uses. For example, wheels for unicycles, tricycles, dicycles, quadracycles, trolleys, trailers, carts, cars, carriages, chariots, motorcycles, monowheels, scooters, skateboards, longboards, sidecars, rickshaws, perambulators, wheelbarrows, wagons, wheelchairs, etc.

The term ‘comprise’ is used in this document with an inclusive not an exclusive meaning. That is to say any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to “comprising only one ...” or by using “consisting”.

In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘can’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus ‘example’, ‘for example’, ‘can’ or ‘may’ refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example. Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

The terms ‘a’ and ‘the’ are used in this document with an inclusive not an exclusive meaning. That is to say any reference to X comprising a/the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use ‘a’ or ‘the’ with an exclusive meaning then it will be made clear in the context. In some circumstances the use of ‘at least one’ or ‘one or more’ may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

The presence of a feature or combination of features in a claim is a reference to that feature or combination of features itself and also to features that achieve substantially the same technical effect (i.e. equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result.

In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon. l/we claim: