Flat headed fastener attachment arrangement for composite wheels

Abstract

An attachment arrangement configured to attach at least one section of a composite wheel to at least one other element, the composite wheel including at least one attachment aperture through which an elongate fastener element is inserted, the attachment arrangement including: (A) a fastening body which includes the elongate fastener element or is configured to be fastened onto the elongate fastener element, the fastener body having a fastener axis extending longitudinally therethrough, the fastening body having an engagement portion comprising a surface substantially perpendicularly aligned to the fastener axis; and (B) an attachment element that includes: • a bearing body which includes a base configured to face a surface of the composite wheel about the attachment aperture; • a fastening aperture through which the elongate fastener element is inserted when in use, the fastening aperture including a fastening axis that aligns with the fastener axis when the fastener is received within the fastening aperture; • an insert section which extends axially away from the base of the bearing body relative to the fastening axis about the fastening aperture, the insert section being configured to extend into the attachment aperture of the composite wheel; and • at least one engagement surface configured to operatively engage the engagement portion of the fastening body when the fastening body fastens to the at least one other element through the elongate fastener element, wherein the base of the bearing body comprises an angled or curved surface which extends upwardly relative to the fastening axis from a section radially spaced away from the insert section relative to the fastening axis to an end of the base proximate to the insert section.

Description

[0001] FLAT HEADED FASTENER ATTACHMENT ARRANGEMENT FOR COMPOSITE WHEELS

[0002] PRIORITY CROSS-REFERENCE

[0003]

[0001] The present application claims priority from Australian Provisional Patent No. 2024904239 filed on 20 December 2024, the contents of which should be understood to be incorporated into this specification by this reference.

[0004] TECHNICAL FIELD

[0005]

[0002] The present invention generally relates to an arrangement for attaching a at least one section of one or more composite wheels to another element such as a wheel mount, or another section of the one or more composite wheels. The invention is particularly applicable to attachment arrangements for carbon fibre wheels used to attach a carbon fibre wheel to a wheel mount of a vehicle, or for attaching two sections of a composite wheel together, and it will be convenient to hereinafter disclose the invention in relation to that exemplary application.

[0006] BACKGROUND TO THE INVENTION

[0007]

[0003] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[0008]

[0004] Attaching composite structures to other components or structures can be challenging. Composite structures, such as carbon fibre components, are generally extremely stiff in the fibre direction, but can have less strength perpendicular to the fibre direction. Attachment apertures for a bolted joint connection are generally formed perpendicular to the fibre direction. Compressive loads through a joint formed through such attachment apertures will therefore be perpendicular to the fibres rather than aligned with them. The stiffness of the material perpendicular to the fibres is quite low. Consequently, a low clamping pressure is required between the head of a bolt / washer and a mount to which it is to be connected to avoid damage. High clamping pressures can damage the composite material at or immediately adjacent a preformed attachment aperture, causing delamination at or immediately adjacent the edge of that attachment aperture. This makes it difficult to achieve a stiff joint with conventional attachment and fastening arrangements.

[0009]

[0005] A number of industries, such as the aerospace industry, use industry embedded fastening systems for attaching components that make up a wheel together and to a wheel mount. For example, in the aerospace industry, wheels are manufactured as two halves and tyre beading processes are completed by placing each wheel half into the tyre on opposite sides and then fastening the wheel halves together. A flat headed fastener (flat headed bolt and nut combination) is used which engages with a flat or slightly conically shaped washer to fasten those wheel halves together. This differs from automotive solutions where the joint is used only to fasten the composite wheel to the vehicle, with most fasteners used in an automotive attachment arrangement for a composite wheel having a conical end which interfaces with a conical washer to assist in load distribution around the attachment aperture of the wheel and also through the overall fastening assembly. Nevertheless, some legacy automotive wheel mount fasteners may still include flat headed type fasteners.

[0010]

[0006] The Applicant has found that the use of a flat headed fastener and complementary flat headed washer is not compatible for fastening a composite material in these joint arrangements. The use of this type of flat fastening arrangement was found to produce yielding in the washer and unacceptable compressive forces on the composite material from the bolt head pulling down, and distorting a flat headed washer placed between the bolt head and composite material. In addition, it was found that the viscoelastic nature of the composite material would relax under the excessive compressive force and the result would be a loss of clamp force in the overall fastening arrangement, allowing unwanted movement in the fastened joint.

[0011]

[0007] The combination of a fastener with a flat fastening head and conventional flat washers therefore provides an uneven and excessive load distribution about the attachment aperture. In most cases, the load is greater in the region closer to the head of the bolt, thus creating an undesirable high compression zone at and around the edge of the attachment aperture.

[0012]

[0008] A conical or Belleville washer may be introduced under a fastener head, for which the purpose is to improve fastener retention by way of adding elasticity to the joint. The conventional purpose of the washer is not to improve surface pressure distribution. In high-load conditions such as the fastening of two wheel halves together for an aerospace wheel, a conical / Belleville washer cannot provide the load distribution required to disperse the bolt tension adequately, which will still lead to joint failure.

[0013]

[0009] One attachment arrangement system that has been used for automotive solutions to address this problem is taught in the Applicant’s international patent publication No. WO2013 / 000009A1 . This arrangement fits through an attachment aperture of a composite wheel and is designed to attach the composite wheel to elongate fastener elements (wheel studs) of a vehicle’s wheel mount. The attachment arrangement comprises a fastening washer having a fastening aperture through which an elongate fastener element from a wheel mount can be inserted when in use and a base configured to face a surface of the composite wheel about the attachment aperture. In addition, the fastening washer has an angled fastening surface which includes at least one engagement surface configured to operatively engage a complementary portion of the fastening nut when the fastening nut is assembled on the elongate fastener element. The fastening arrangement also includes a sleeve which extends axially relative to the fastening axis outwardly from the base about the fastening aperture and into the attachment aperture of the composite wheel.

[0014]

[0010] However, the Applicant has found that this existing attachment arrangement cannot be successfully used with flat headed type fasteners, as the configuration of the attachment element still provides an uneven load distribution about the attachment aperture when used with this type of fastener.

[0015]

[0011] It would therefore be desirable to provide an improved or alternate attachment arrangement for use with or in a composite wheel that overcomes one or more of the above limitations. SUMMARY OF THE INVENTION

[0016] Attachment Arrangement

[0017]

[0012] A first aspect of the present invention provides an attachment arrangement configured to attach at least one section of a composite wheel to at least one other element, the composite wheel including at least one attachment aperture through which an elongate fastener element is inserted, the attachment arrangement including:

[0018] (A) a fastening body which includes the elongate fastener element or is configured to be fastened onto the elongate fastener element, the fastener body having a fastener axis extending longitudinally therethrough, the fastening body having an engagement portion comprising a surface substantially perpendicularly aligned to the fastener axis; and

[0019] (B) an attachment element that includes:

[0020] • a bearing body which includes a base configured to face a surface of the composite wheel about the attachment aperture;

[0021] • a fastening aperture through which the elongate fastener element is inserted when in use, the fastening aperture including a fastening axis that aligns with the fastener axis when the fastener is received within the fastening aperture;

[0022] • an insert section which extends axially away from the base of the bearing body relative to the fastening axis about the fastening aperture, the insert section being configured to extend into the attachment aperture of the composite wheel; and

[0023] • at least one engagement surface configured to operatively engage the engagement portion of the fastening body when the fastening body fastens to the at least one other element through the elongate fastener element, wherein the base of the bearing body comprises an angled (sloped) or curved surface which extends upwardly relative to the fastening axis from a section radially spaced away from the insert section relative to the fastening axis to an end of the base proximate to the insert section.

[0024]

[0013] The new and advantageous design of the attachment arrangement of the present invention provides an extremely stiff fastening to the wheel mount relative to the fastening body without damaging the composite wheel when using a flat headed fastener or fastening body for this joint. In this sense, the attachment arrangement of the present invention provides the same advantages as the Applicant’s previous attachment arrangement configuration taught in W02013 / 000009A1 , but configured and optimised for this type of fastener. Like the Applicant’s previous attachment arrangements, the resulting extremely stiff fastening to the other element, for example a wheel mount, relative to the fastening body assists in reducing or substantially eliminate loss of fastening torque associated with any external loading conditions in the attachment arrangement. Progressive loss of fastening torque can result in the bolted joint loosening and can cause the fastener to rotate resulting in further torque loss and reduction of the joint clamping load. Without this improvement, the visco-elastic properties of the composite laminate result in material movement and the loss of bolt tension.

[0025]

[0014] It should be appreciated that in this specification a “flat headed” fastener is generally referring to fasteners that are not conical, i.e. do not have a conical engagement surface under the head or flange of the fastener. A “flat headed” fastener can encompass a range of non-conical headed fasteners that include a flat or substantially flat head (heads that are not perfectly flat), which could equally be used in the attachment arrangement of the present invention. In this sense, the fastening body is defined as having an engagement portion comprising a surface substantially perpendicularly aligned to the fastener axis - i.e. that surface is not necessarily exactly perpendicularly aligned to the fastener axis but may have some variation, for example contours, slight angled or curved surface which still would enable the fastener to interact within the attachment arrangement within the scope of the present invention.

[0026] Bearing Body

[0027]

[0015] The bearing body section of the attachment arrangement of the present invention is configured to provide an increased clamping contact area with the surface of the composite wheel surrounding the attachment aperture and thereby increase the area through which the clamping force is applied around the attachment aperture. The bearing body is configured to engage the surface of the composite wheel surrounding the attachment aperture through its base.

[0016] In the present invention, the base of the bearing body has been adapted to provide a more uniform surface pressure on the composite material of the composite wheel around the attachment apertures under full fastening compression. The base of the bearing body comprises a contact surface configured to abut the contact surface of the composite wheel about the attachment aperture, or operatively engage the contact surface of the composite wheel through an intermediary body, for example a washer or other member such as a shared bearing plate, in embodiments where that may be used. The slope or curve on the lower side of the base has been configured to drive initial engagement (direct engagement or operative engagement) between the base of the bearing body and the contact surface thereof (directly or indirectly through an intermediary body) of the composite wheel away from the attachment aperture, spaced radially away from the insert section, and preferably toward a section of or proximate the distal end or perimeter (for example the outer diameter) of the base of the bearing body. The remaining sections of the base of the bearing body between that radially spaced section and the attachment aperture are spaced away from the contact surface in this initial contact (again directly or indirectly through an intermediary body). Thus, as the fastening body is tightened using the elongate fastener about the fastening axis, the central region of the base of the bearing body pulls down onto the contact surface of the composite wheel creating an increasingly uniform pressure distribution on the composite material (typically a laminate) of the composite wheel contact surface around the attachment apertures when further tightened (directly or indirectly through an intermediary body).

[0028]

[0017] The base of the bearing body is preferably configured to transfer compression force from the bearing body through to the composite wheel. The achievement of uniform surface pressure on the composite material of the composite wheel around the attachment apertures depends on various input parameters for example stiffness of laminate, type of fastener / bolt, configuration of the base of the bearing body, configuration of the engagement surface, fastening torque, and the like.

[0018] As noted above, it should be appreciated that the base of the bearing body comprises a contact surface configured to operatively engage the contact surface of the composite wheel about the attachment aperture. In such embodiments, the base of the bearing body contacts the surface of the composite wheel about the attachment aperture through an intermediary body. This contact or engagement may be a direct engagement, or an indirect / operative engagement through said intermediary body. That intermediary body can be a washer, plate, or other member such as a shared bearing plate, in embodiments where that may be used.

[0029]

[0019] The base of the bearing body comprises an angled (sloped) or curved surface which extends and is angled upwardly relative to the fastening axis from that said section (of the base of the bearing body) that is radially spaced away from the insert section. That radially spaced away section is therefore located lower or below the end of the base that is proximate to the insert section relative to the fastening axis. The radially spaced away section of the base of the bearing body can have any suitable configuration. In many embodiments, said section that is radially spaced away from the insert section comprises a circumferential section or perimeter defining the outer end or edge of the slope or curve. Similarly, said end of the base proximate to the insert section can have any suitable configuration. In many embodiments, this end comprises a circumferential section or perimeter defining the other / opposite end or edge of the slope or curve to the radially spaced apart section.

[0030]

[0020] The slope of the base of the bearing body can commence at any suitable point or section of the base spaced away from the insert section (and by extension away from the attachment aperture). However, practically it is preferable that that spaced apart section is located a substantive distance away from the insert section, and more preferably at or at least proximate to the distal outer end of that base contact surface relative to the fastening axis. In embodiments, the base of the bearing body can therefore comprise an angled (sloped) or curved surface which extends upwardly relative to the fastening axis from a distal outer end thereof relative to the fastening axis or an outer section of the base proximate to the distal outer end, to an end of the base proximate to the insert section.

[0031]

[0021] The base of the bearing body forms a conical shaped cavity between the upper contact surface of the of the composite wheel and that base surface when the bearing body is not tightened.

[0032]

[0022] The actual angle or curved shape of the base surface depends on various factors. In embodiments, the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. In embodiments, the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 5 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. However, it should be appreciated that other angles and shapes may also be used to achieve the same function.

[0033]

[0023] It should be appreciated that where the attachment arrangement comprises a centre lock wheel attachment arrangement, the base of the bearing body may comprise a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 1 to 7 degrees, more preferably 2 to 6 degrees, yet more preferably from 3 to 5 degrees, for example around 4.5 degrees.

[0034]

[0024] It should be appreciated that the average angle comprises the average or mean rate of growth / expansion of the base surface between the radially spaced away section (for example the distal outer end of the base) and the end of the base proximate to the insert section perpendicular to the fastening axis. In embodiments where the base comprises a linear slope, this will substantially correspond with the angle of that linear slope. In other embodiments where the base is curved or otherwise non-linear, the average expansion angle will be the average or mean angle formed from the surfaces that comprise the base. For example, for a curved surface the average expansion angle will be the average angle of that curve.

[0035]

[0025] In some embodiments, the base of the bearing body comprises a curved surface, preferably a convex curved surface, more preferably a convex profile, more preferably a slight convex profile providing an initial engagement surface for a contact surface of the composite wheel about the radially spaced away section (directly or indirectly through an intermediary body). The lowest point of the curve relative to the fastening axis, in some embodiments the apex of the curve, provides that initial engagement surface.

[0036]

[0026] It should be appreciated that whilst in some embodiments, the base may comprise a flat and / or contour-less surface. In other embodiments, the base of the bearing body has a contoured engagement face having a substantially complementary configuration to the surface of the composite wheel on which the bearing body engages. More preferably, the base has complementary contours and features to the surface of the composite wheel about the attachment aperture. For example, the engagement surface can be configured to have a substantially complementary configuration to the engagement portion of the fastening body. This does not necessarily mean that these two surfaces have mirrored configurations, rather the surfaces are designed to mate together in a manner that provides an advantageous force distribution between the fastening body and the bearing body through that section of the composite wheel which is being fastened to the other element. In embodiments, the engagement surface is angled or curved relative to the fastening axis.

[0037]

[0027] The engagement surface can also be adapted to assist in force transfer from the fastening body through the bearing body and onto the contact surface of the composite wheel around the attachment aperture(s) (directly or indirectly through an intermediary body). In embodiments, the engagement surface may comprise an angled (sloped) or curved surface which extends and is angled downwardly relative to the fastening axis from a section radially spaced away from the fastening aperture to an end of the engagement surface proximate to the fastening aperture. That radially spaced away section can be any section radially remote from the fastening aperture. In many embodiments, the angled (sloped) or curved surface extends and is angled downwardly relative to the fastening axis from a distal outer end or an outer section of the engagement surface proximate to the distal outer end thereof, to an end of the engagement surface proximate to the fastening aperture. In these embodiments, the engagement surface is angled, and the base is also angled. These two angles converge towards each other closest to the attachment aperture. Here, when the engagement portion of the fastening body contacts that radial spaced away section first, for example a point near the outer perimeter of the engagement surface (or via / through an insert / washer in some embodiments) which transfers the force to an outer section (for example the outer perimeter) of the base of the bearing body to the composite material of the composite wheel first. As the fastening body is tightened (for example, the elongate fastener), more of the flat surface of the engagement portion of the fastening body contacts the top engagement surface (directly or through a washer / insert), and more of the base of the bearing body contacts the contact area of the composite wheel around the attachment aperture. Thus when the joint is tightened, the force is transferred progressively towards the attachment aperture. The outcome of this behaviour is that when you reach full bolt tension you have uniform distribution of pressure on the contact area of the composite wheel around the attachment aperture.

[0038]

[0028] The radially spaced away section of the engagement surface can have any suitable configuration. In many embodiments, said section (of the engagement surface) that is radially spaced away from the fastening axis comprises a circumferential section or perimeter defining the outer end or edge of the slope or curve. Similarly, said end of the engagement surface proximate to the fastening aperture can have any suitable configuration. In many embodiments, this end comprises a circumferential section or perimeter defining the other / opposite end or edge of the slope or curve to the radially spaced apart section.

[0039]

[0029] Like the base of the bearing body, the actual angle of engagement surface depends on various factors. Similarly, the actual angles of each of the base and engagement surfaces relative to each other vary depending on various factors. In embodiments, the engagement surface comprises a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. In embodiments, the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 5 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. However, it should be appreciated that other angles and shapes may also be used to achieve the same function. It should be appreciated that where the attachment arrangement comprises a centre lock wheel attachment arrangement, the base of the bearing body may comprise a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 1 to 7 degrees, more preferably 2 to 6 degrees, yet more preferably from 3 to 5 degrees, for example around 4.5 degrees.

[0040]

[0030] In some embodiments, the engagement surface comprises a curved surface, preferably a convex curved surface, more preferably a convex profile, more preferably a slight convex profile providing an initial engagement surface for the engagement portion of the fastening body about the radially spaced away section thereof, for example the distal outer end or an outer section of the engagement surface in the relevant embodiments. The slope or curve, and preferred convexity on the engagement surface is to drive initial contact and load from the bolt head toward a section of the engagement surface of the bearing body that is radially spaced away from the fastening aperture, and thus the attachment aperture, during initial clamp-up.

[0041]

[0031] The bearing body can have any suitable shape and / or configuration. The geometric shape of the bearing body can also be tailored to fit the available space in the proximate and adjacent surface on that section of the composite wheel. In some embodiments, the bearing body has a circular or toroidal shape or the like. In some embodiments, the geometric shape of the bearing body may comprise at least one of circular, ovular, triangular, square, rectangular or other shape as required. In other embodiments, the bearing body can have a planar configuration. In some embodiments, the bearing body includes an outer profile comprising at least one of: a straight angular face, a curved face; or a pocketed face.

[0042]

[0032] In embodiments, a curved face can be used to maximise the material thickness nearest the outer edge. In embodiments, a pocketed face configuration can be used to increase bending stiffness in a particular region of the insert, and remove it from another.

[0043]

[0033] The base of the bearing body is preferably configured with sufficient surface area sufficient area under the bearing body to reduce the compressive load on the laminate to a threshold load of less than 150 MPa, preferably less than 100 MPa. It should be appreciated that this threshold load is governed by material selection, joint efficiency, bolt cone angle / diameter / material, bolt torque or the like. The outcome is that for any operational environment, the laminate compressive force should not exceed a value which triggers an unacceptable bolt tension reduction. The aim of the configuration of the attachment element is to move pressure from the inside edge of the aperture (hole) that prevents the least supported portion of the composite falling into the aperture and exceeding the value at which bolt retention becomes a problem.

[0044]

[0034] The bearing body is not necessarily restricted to provide an increased clamping contact area with the surface of the composite wheel surrounding a single attachment aperture. Where the composite wheel includes at least two attachment apertures, and the bearing body can be configured to extend over the surface of the composite wheel between and around at least two of these attachment apertures. In some embodiments, the bearing body can be configured to extend over the surface of the composite wheel between and around all of the attachment apertures. In these embodiments, the bearing body can comprise a substantially planar body, preferably a plate, which extends between and around each attachment aperture. The bearing body is therefore configured as a shared body that provides an increased clamping contact area with the surface of the composite wheel over the surface of the composite wheel around each of the attachment apertures. In this shared bearing body configuration, that bearing body includes at least two fastening apertures and at least two insert sections corresponding to the number of attachment apertures in said composite wheel, each insert section extending into a respective attachment aperture of the composite wheel. The attachment element for each attachment aperture therefore includes a shared or common bearing body which extends over and bears against the surface of the composite wheel. However, a fastening aperture, an insert section and at least one engagement surface are provided within each attachment aperture. A fastening body and associated elongate fastener are received through each fastening aperture. It should be appreciated that the base of the shared bearing body may directly engage or abut a surface of the composite wheel, or could contact that surface through an intermediary body, for example another plate, washers or the like.

[0045]

[0035] In alternate embodiments where the composite wheel includes at least two attachment apertures, and a shared bearing plate could be used to extend over the surface of the composite wheel between and around at least two of these attachment apertures onto which the bearing body of each attachment arrangement according to the first aspect of the present invention can be received and seated. The bearing plate provides an additional engagement surface between the base of the bearing body and engagement of said base of the bearing body with the surface of the composite wheel. In some embodiments, this bearing plate can be configured to extend over the surface of the composite wheel between and around all of the attachment apertures. The bearing plate can be configured as a shared body that provides an increased clamping contact area over the surface of the composite wheel around each of the attachment apertures. The attachment arrangement follows the configuration as described for the first aspect of the present invention, but with this intermediary bearing plate.

[0046] Insert Section

[0047]

[0036] The insert section can include at least one retention feature which resists withdrawal of the insert section from the attachment aperture. The retention features are included to keep the attachment element secured when, for example, the wheel is removed from the wheel hub or the wheel halves (eg, of an aerospace wheel) are disassembled. The insert section may include a distal end configured to receive a retention element, preferably a clip (circlip or the like) configured to prevent withdrawal of the insert section through the attachment aperture. In those embodiments that include a backing plate, the insert section may include a distal end configured to receive a retention element, preferably a clip (circlip or the like) configured to prevent withdrawal of the insert section through the insert section aperture of the backing element. This retention feature can be any element or formation. In one embodiment, the distal end of the insert section is inserted through the insert section aperture and a retention formation, for example a clip, is fastened onto the distal end of the insert section. That retention formation can comprise any suitable fastening or fixing body, including a clip, peg, clamp, rod, pin, washer, or the like. For example, the retention formation can be a circlip, press fit washer or a deformation feature on the end of the insert section. In one embodiment, the retention formation comprises a fixing clip which is seated or otherwise fitted into a groove or trench included in a portion of this distal end of the insert section which extends through the attachment aperture. The outer diameter of the fixing clip has a greater size than the insert section aperture. This fixing clip can be arranged to still allow the insert section to slide relative within the attachment aperture in one direction but prevents the whole assembly from falling apart when the fastener element is removed. In one embodiment, the distal end of the insert section is inserted through the attachment aperture and / or the insert section aperture (where applicable) and then the end is deformed to a greater size than the insert section aperture. This deformation can have any shape or configuration. In one embodiment, the distal edge is deformed to form a rolled edge.

[0048]

[0037] In some embodiments, the insert section is configured with a radial width relative to the fastening axis that is smaller than the radial width relative to the fastening axis of the fastening aperture. This forms a radial gap between the outside of the insert section and the internal sides of attachment aperture. This reduces the possibility of the insert section transferring some of the clamping load to the walls of the attachment aperture and also provides clearance for a degree of expansion of the insert section within the attachment aperture once the fastening body is engaged within and creates a compression load in the attachment element.

[0049]

[0038] In other embodiments, the insert section is shaped to have an interference fit within the attachment aperture. This interference fit can be designed to act as a retention feature which resists withdrawal of the insert section from the attachment aperture. This interference fit of the insert section can also be designed to assist the attachment element resisting inward rotation of the fastening body when the arrangement is being tightened.

[0050]

[0039] The insert section may have some form of anti-rotation feature such as dowel pins, or shaped insert portion (Wankel inserts) whose purpose is to ensure the insert does not rotate during bolt tightening, which may damage the laminate. In embodiments, the base of the bearing body may include a fixing feature which substantially prevents axial rotation of the insert section within the attachment aperture about the fastening axis. This feature may comprise one of more projections, spigots, elongate, flanges or embossments that are seated in at least one complementary groove, hole, aperture, detent, recess or depression in the surface of the composite wheel. In other embodiments, the insert section aperture and distal end of the insert section can have a complementary configuration in some forms which substantially prevents axial rotation of the insert section within the attachment aperture about the fastening axis. The complementary configuration can comprise any feature that provides a locked fit between the insert section and insert section aperture including (but not limited to) at least one of a polygonal shape, irregular shape, spline, flat, recess, shoulder, projection, spigot, key, cavity, groove or finger. In a preferred embodiment, the insert section aperture and distal end of the insert section have a complementary hexagonal shape. This anti-rotation feature ensures the attachment element does not rotate in the attachment apertures of the composite wheel when the fastening body is being tightened and / or in use.

[0051]

[0040] The insert section can have any suitable cross-section. In preferred forms, the insert section has a circular or polygonal radial cross-section relative to the fastening axis. The bearing body and insert section are preferably integrally formed as the attachment element from a single piece of material, such as metal which could be cast, forged or machined from billet. In other embodiments, the bearing body and insert section can be formed from two or more separate elements which can be secured together to form the attachment element of the present invention.

[0052] The Fastening Body / Bodies

[0041] The fastening body or bodies used in the attachment arrangement of this first aspect of the present invention can have any suitable configuration.

[0053]

[0042] The fastening body in wheel attachment (vehicle) embodiments can comprise any suitable fastener arrangement used to attach a composite wheel to the mount.

[0054]

[0043] The fastening body for wheel attachment embodiments of this invention may have a bolt configuration and / or a nut configuration. In some embodiments, the fastening body comprises a bolt configuration, for example a wheel bolt. In this embodiment, the fastening body comprises a fastening bolt which includes a fastening head including the engagement portion and the elongate fastener, the elongate fastener being configured to be connected in or through the at least one other element, for example a wheel mount, via for example a threaded connection. In these embodiments, the fastening body fastens to the mount through the elongate fastener element by the fastening bolt being fastened into the mount. In embodiments, the elongate fastener element section of the fastening bolt is threaded and is received within a complementary threaded aperture in the mount. However, it should be appreciated that other forms of interconnections are possible to connect / fix the fastening bolt to the mount.

[0055]

[0044] In other wheel attachment embodiments, the fastening body comprises a fastening nut, for example a wheel nut. In these embodiments, the fastening nut is configured to be assembled onto the elongate fastener element to operatively engage the engagement portion thereof with the at least one engagement surface. In these embodiments, the elongate fastener element can comprise any suitable interlocking fastening arrangement with the fastening body. In a preferred form, the elongate fastener element includes an external threaded surface, and the fastening body includes a complementary threaded internal bore. In such embodiments, the elongate fastener element extends outwardly from the mount, preferably forming part of the mount. Here, the fastening body fastens to the mount through the elongate fastener element through the threaded internal bore of the fastening nut being received and fastened over the external threaded surface of the elongate fastener element.

[0045] In particular wheel attachment embodiments, the composite wheel is of a centre lock type in which the attachment aperture has a complementary thread to the elongate fastener element. The elongate fastener element can have an integrated threaded head.

[0056]

[0046] The fastening body in aerospace embodiments can comprise any suitable fastener arrangement used to attach two wheel halves together through a common attachment aperture / through-hole. In many aerospace embodiments, two fastening bodies are required either side of the joint, as will be explained below in the specification in more detail. In embodiments, a first fastening body comprises a fastening bolt which includes a fastening head including the engagement portion and the elongate fastener, and a second fastening body comprises a fastening nut.

[0057]

[0047] The engagement portion comprises a surface substantially perpendicularly aligned to the fastener axis. The surface can have any suitable configuration. In some embodiments, the surface of the engagement portion may be a planar or flat surface. In other embodiments, the surface of the engagement portion may have contours, for example a rib, trench or other feature that may function in relation to the engagement surface of the bearing body. In some embodiments, the surface of the engagement portion may include a curved portion, for example a convex portion or section. In yet further embodiments, the surface of the engagement portion may have a slight or minor angle, for example an angle from 0.1 to 10 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. In embodiments, the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 5 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. However, it should be appreciated that other angles and shapes may also be used to achieve the same function. It should be appreciated that where the attachment arrangement comprises a centre lock wheel attachment arrangement, the base of the bearing body may comprise a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 1 to 7 degrees, more preferably 2 to 6 degrees, yet more preferably from 3 to 5 degrees, for example around 4.5 degrees. It should be understood that even with that minor angle, the engagement portion still comprises a surface that is substantially perpendicularly aligned to the fastener axis.

[0058]

[0048] In embodiments, the engagement surface and the engagement portion have a substantially complementary configuration. The substantially complementary configuration of the engagement surface and the engagement portion function to facilitate force transfer between the engagement surface and the engagement portion. Preferably, the substantially complementary configuration has cooperating shaped surfaces that engage together. However, it should be appreciated that in some embodiments, this may involve cooperating designs where only part of the engagement portion directly contacts the corresponding area on the engagement surface. In this sense, the engagement between the engagement surface and the engagement portion does not require all, or substantially all, of the engagement portion to contact the engagement surface.

[0059]

[0049] It should be appreciated that the engagement surface and the corresponding / cooperating engagement portion of the fastening body can comprise a single surface or may comprise two or more separate or individual surfaces in the respective attachment element and fastening body. For example, in some embodiments the engagement surface may comprise a ramped or curved surface which extends circumferentially within an inner surface of the insert section. In other embodiments, there could be two or more engagement surfaces within a single individual attachment element, for example, two semicircular surfaces extending from an inner surface of the insert section which are circumferentially spaced apart about the fastening axis by a gap, recess, projection or the like.

[0060]

[0050] The at least one engagement surface is configured to operatively engage the engagement portion of the fastening body when the fastening body fastens to the at least one other element through the elongate fastener element. That operative engagement may be a direct engagement where the two surfaces directly engage through contact or the like, or that operative engagement may be through one or more intermediary bodies, for example a washer, insert or the like.

[0051] It should be appreciated, that in embodiments at least one washer or other insert element, for example a flat / planar washer can be located between the engagement portion of the fastening body and the engagement surface of the bearing body. The washer or insert is preferably configured with a substantially complementary configuration to both the engagement portion of the fastening body and the engagement surface of the bearing body.

[0061]

[0052] The engagement surface can extend from section of the bearing body and / or insert section that is in a position to engage with the engagement portion of the fastening body when that fastening body engages with the bearing body and is fastened onto the elongate fastener element. In embodiments, the engagement surface is formed on an upper, preferably top surface of the bearing body. In other embodiments, the engagement surface can extend from a portion of the inner surface of the bearing body and / or insert section that is in a position to engage with the engagement portion of the fastening body when that fastening body engages with the bearing body and is fastened onto the elongate fastener element. In embodiments, the engagement surface comprises a substantially annular portion of an inner wall of the bearing body. In other embodiments, the engagement surface comprises a substantially annular portion of an inner wall of the insert section. In other embodiments, the engagement surface comprises a substantially annular portion of an inner wall of both the bearing body and the insert section.

[0062]

[0053] The other element on to which the composite wheel is fastened using the attachment arrangement can comprise any suitable fixture, mount, surface, wheel part or section, or body. In many embodiments, the at least one other element is selected from: a wheel mount; another section of an adjoining composite wheel, or another section of the at least one composite wheel.

[0063] Wheel Attachment (Vehicle) Arrangements

[0064]

[0054] The attachment arrangement can be configured to attach at least one section of a composite wheel to a mount, preferably a wheel mount, for example the wheel mount of a vehicle. In these embodiments, the elongate fastener extends from or through the wheel mount, and through the composite wheel to attach the composite wheel onto the wheel mount. In these embodiments, the insert section is preferably configured to extend into and through the attachment aperture of the composite wheel. Moreover, the distal end of the insert section preferably extends into the attachment aperture of the composite wheel and is spaced apart from the wheel mount, or from or in an element located in, on, integral with, or adjacent to the wheel mount such that the distal end of the insert section does not directly engage with the wheel mount and / or said element.

[0065]

[0055] The distal end of the insert section can be designed to extend into the attachment aperture of the composite wheel and be spaced apart from the wheel mount, or from or in an element located in, on, integral with, or adjacent to the wheel mount. Preferably, the distal end of the insert section is designed to extend into the attachment aperture of the composite wheel and be spaced apart from a surface of the wheel mount, or from or in a surface of an element located in, on, integral with or adjacent to the wheel mount. In this sense, the distal end of the insert section is spaced apart from the wheel mount and / or said element such that the distal end of the insert section does not directly engage with, preferably does not directly contact the wheel mount and / or said element. This typically entails the distal end of the insert section not directly engaging with, preferably not directly contacting a proximate or adjoining surface of the wheel mount and / or said element. This spaced apart arrangement precludes, preferably prevents, that insert section from establishing or otherwise having direct force transfer with, through or onto the wheel mount and / or said element. That spacing may be an axial and / or radial spacing relative to the fastening axis from a surface of the wheel mount and / or said element located in, on or adjacent to the wheel mount. The spacing is therefore configured so that the distal end of the insert section does not directly contact or directly engage with a proximate or adjoining surface of the wheel mount or said element.

[0066]

[0056] It should be understood that the wheel mount (or wheel hub) is the mounting element on a vehicle or other transport arrangement for the composite wheel. It should also be understood that said element, which is in, on, integral with or adjacent to the wheel mount may comprise an element that is formed integral with the wheel mount, is located on or in (within) the wheel mount, is attached to the wheel mount, or is located adjacent to the wheel mount. In some embodiments, said element comprises a backing plate which is located adjacent to the wheel mount. In embodiments, the element, for example a backing plate, may be located adjacent to but is spaced apart from the wheel mount.

[0067]

[0057] In embodiments, the attachment arrangement may include a further component, such as a backing element, locating element, backing washer, clip such as a circlip or the like which locates the base of the insert section within the attachment aperture.

[0068]

[0058] The attachment arrangement can further include at least one backing element configured to be inserted between the mount and the composite wheel. The backing element provides a large surface on the opposite side of the attachment aperture to the bearing body against which the composite wheel can be clamped by the attachment element. The at least one backing element can include at least one section of the fastening aperture.

[0069]

[0059] The distal end of the insert section is preferably configured to be received in an insert section aperture located in the wheel mount or the at least one backing element. The backing element can include at least one section of the insert section aperture, and preferably the entire insert section aperture. The insert section aperture is preferably sized to allow at least a portion of the insert section to move through the insert section aperture, preferably sized to provide a sliding fit between a portion of the distal end of the insert section and the at least one backing element. In some embodiments, the insert section aperture includes a stepped diameter that provides a first diameter sized to accommodate and seat the insert section therein, and a second diameter sized to accommodate the elongate element.

[0070]

[0060] In some embodiments, the at least one backing element includes a recess sized to receive a portion of the insert section. The backing element can therefore be configured so that at least a portion of the at least one engagement surface is located within said recess of the at least one backing element. In some embodiments, said recess receives and encloses a distal end of the insert section. However, in other embodiments, the distal end of the insert section extends through the backing element. The insert section preferably includes a cutout section to provide clearance between the distal end of the insert section and a section of the surface of the backing element proximal the insert section aperture. This type of cutout section may comprise a step in the distal end of the insert section. The step preferably includes a base section facing the backing element configured to be spaced apart from the backing element.

[0071]

[0061] In a preferred form, the backing element comprises a plate configured to abut a surface of the composite wheel about the attachment aperture. Where the composite wheel includes at least two fastening apertures, the backing element can include at least the same number of insert section apertures configured to cooperate with insert sections from respective bearing bodies inserted through each of these fastening apertures. For example, where the composite wheel is a wheel (for example a carbon fibre wheel) which attaches to a wheel mount using three or more wheel studs, the backing element can comprise an annular plate which includes a corresponding number of insert section apertures to the number of wheel studs.

[0072]

[0062] It should be appreciated that in some embodiments, the backing element comprises a separate element in the attachment arrangement. However, in alternate embodiments the backing element may be formed by or in conjunction with another element, for example the mount. In some embodiments, the mount may provide some or all of the elements of the backing element.

[0073]

[0063] The insert section is configured to extend into and through the attachment aperture of the composite wheel and in some embodiments can be received in a complementary shaped insert section aperture located in the wheel mount or in an element located adjacent the mount. In some embodiments, the insert section aperture may be formed in the mount.

[0074]

[0064] As noted above, the insert section aperture is preferably sized to allow at least a portion of the insert section to move through the insert section aperture. The insert section aperture is preferably sized to provide a sliding fit between a portion of the distal end of the insert section and the backing element. In this sense, clearance is provided between this distal end of the insert section and the backing element to ensure the clamping load is transmitted from the engagement surface through the composite structure of the composite wheel and the backing element and into the vehicle wheel mount. The insert section can therefore be designed to provide a clearance between the bottom of the insert section and the surface surrounding the insert section aperture. In embodiments, this clearance can be designed to provide a sliding fit between the insert section and the element which includes the insert section aperture so that the insert section can slide through the insert section aperture when the attachment arrangement is compressed. This reduces the possibility of the insert section contacting the mount and transferring some of the clamping load to the mount or radially within the attachment aperture and / or insert section aperture. It is preferable for all the compression loading from the fastener to go through the composite structure.

[0075]

[0065] The distal end of the insert section is preferably spaced apart from that section of the surface the backing element proximal the insert section aperture. This spacing provides clearance between the distal end of the insert section and the backing element to allow a degree of expansion of the insert section within the attachment aperture once the fastening body is engaged within and creates a compression load in the attachment element. In embodiments, the insert section may include a cutout section to provide clearance between the distal end of the insert section and a section of the surface of the backing element proximal the insert section aperture. The cutout section can comprise any depression, groove or cavity configured to provide the required clearance. In one embodiment, the cutout section comprises a step in the distal end of the insert section. The step preferably includes a base section facing the backing element configured to be spaced apart from the backing element.

[0076] Aerospace Joint Applications

[0077]

[0066] The attachment arrangement can also be used in a modified vehicle based application, whereby the joint is not primarily for wheel to vehicle attachment, but for wheel-wheel attachment of a composite joint. For example, aerospace wheels are manufactured as two halves and tyre beading processes are completed by placing each wheel half into the tyre on opposite sides and fastening together. In these embodiments, the attachment arrangement is configured to attach at least a first section of a composite wheel to second section of a composite wheel (which comprises said at least one other element). The first section and the second section of the composite wheel typically comprise complementary halves which can be coupled together by the attachment arrangement. This differs from automotive solutions where the joint is used only to fasten the wheel to the vehicle.

[0078]

[0067] In these aerospace type wheel embodiments, the attachment arrangement of the first aspect of the present invention can comprise: a fastening arrangement comprising two fastening bodies which are operatively associated with an elongate fastener element, at least one of the fastening bodies being configured to be fastened onto the elongate fastener element, each fastener body having a fastener axis extending longitudinally therethrough, each fastening body having an engagement portion comprising a surface substantially perpendicularly aligned to the fastener axis; and two attachment elements, each insert being associated with one of said two fastening bodies, each attachment element including:

[0079] - a bearing body which includes a base configured to face a surface of the composite wheel about the attachment aperture;

[0080] - a fastening aperture through which the elongate fastener element is inserted when in use, the fastening aperture including a fastening axis that aligns with the fastener axis when the fastener is received within the fastening aperture;

[0081] - an insert section which extends axially away from the base of the bearing body relative to the fastening axis about the fastening aperture, the insert section being configured to extend into the attachment aperture of the composite wheel; and

[0082] - at least one engagement surface configured to operatively engage the engagement portion of the associated fastening body when that fastening body fastens through or by the elongate fastener element, wherein the base of each bearing body comprises an angled or curved surface which extends upwardly relative to the fastening axis from a section radially spaced away from the insert section relative to the fastening axis to an end of the base proximate to the insert section.

[0068] In such embodiments, two attachment elements are used, positioned on opposite ends of the elongate fastener and opposite sides of the joint laminate. There is a common through-hole through the joint laminate of the carbon fibre wheel halves for each attachment element.

[0083]

[0069] Unlike automotive solutions, the insert section (sleeve / shank) is preferably designed to not extend beyond the mating surfaces of the laminates of each wheel half. The insert section is preferably configured to terminate within the attachment aperture of the section of composite wheel in which the attachment element is located. Accordingly, the insert section is typically configured to be sufficiently short that even under the greatest compressive stresses, the distal end of the insert section preferably should never contact the distal end of the opposing insert section. In this sense, the insert section of each attachment element is configured with a distal end that is spaced away from the distal end of the opposing insert section.

[0084]

[0070] Alternatively, the insert section can be configured such that no part of the insert section is able to contact the opposite feature during any operational or clamp loadings. This may not necessarily require there to be a gap between the distal ends of each insert section. For example, the diameter of one insert section may be less than the diameter of the other insert section, allowing the first insert section to extend into the second insert section across the mating surfaces of the laminate of the two wheel halves.

[0085]

[0071] In aerospace embodiments, a first fastening body comprises a fastening bolt which includes a fastening head including the engagement portion and the elongate fastener, the elongate fastener being configured to be connected in or through the common through-hole through the joint laminate of the carbon fibre wheel halves for each attachment element. The engagement portion of the fastening head is configured to operatively engage the engagement portion thereof with the at least one engagement surface of an associated bearing body. A second fastening body comprises a fastening nut. The fastening nut is configured to be assembled onto the other end of the elongate fastener element to operatively engage the engagement portion thereof with the at least one engagement surface of an associated bearing body. In some embodiments, the elongate fastener element includes an external threaded surface, and the fastening nut includes a complementary threaded internal bore. The fastening bodies take the features of fastening bodies described previously in the specification.

[0086]

[0072] It should be appreciated that the bearing body of each set of attachment elements (i.e. associated with each wheel half) could form part of a shared plate. As described above, the composite wheel includes at least two attachment apertures, and each bearing body can be incorporated into a common plate that can be configured to extend between and around at least two of these attachment apertures. In some embodiments, each bearing body can be configured to be incorporated into a shared or common plate that extends between and around all of the attachment apertures on each respective side of the wheel halves.

[0087]

[0073] The attachment element is preferably sized for each unique design taking into account variables such as but not limited to;

[0088] - elongate fastener length which affects stack height; and

[0089] - contact diameters between the engagement portion of the fastening body and the engagement surface of the bearing body.

[0090] Recessed Embodiments

[0091]

[0074] Where a shorter elongate fastener length is required, the composite wheel can include a recess to accommodate that shortened length, and / or the bearing body and insert section can be configured to receive the fastening body therein.

[0092]

[0075] In some embodiments, the attachment element is configured to be received inside a recess formed in the adjoining section of the composite wheel. In this respect, the composite wheel can include a recess formed for example by machining or moulding a suitable pocket. In other embodiments, the bearing body can be configured to receive the fastening body therein, to enable the engagement portion of the fastening body to engage with the engagement surface. In order to accommodate the fastening body, the bearing body preferably includes a body aperture sized to receive the fastening body. The body aperture comprises a circular or polygonal shaped recess sized to accommodate the fastening body, and if required a portion of tool used to manipulate the fastening body. The body aperture typically comprises a recess which steps into the fastening aperture.

[0093]

[0076] In embodiments, the body aperture extends into the insert section of the attachment element. Thus, part of the insert section can be configured to receive a portion of the fastening body. In some embodiments, the body aperture is located axially below the base of the bearing body relative to the fastening axis. This allows at least a position of the fastening body and engagement portion thereof to be housed and / or recessed within the bearing body, and in some cases housed and / or recessed into the insert section.

[0094]

[0077] Where the insert section is configured to receive a portion of the fastening body, the insert section can include a first section having a first internal diameter to receive the fastening body, and a second section having a second internal diameter sized to capture the fastening body, and through which the elongate fastener element can extend. Here, the insert section has a stepped diameter where the first section receives and encloses the fastening body, whilst the second section includes the at least one engagement surface and is sized to receive the elongate fastener element therethrough, and have a diameter that captures the fastening body - i.e. is sized so that that the fastening body cannot fully extend through an aperture formed with the second diameter.

[0095]

[0078] In embodiments where the fastening body recesses through the bearing body, the engagement surface of the arrangement can have at least a portion positioned below the base of the bearing body and below the top surface level of the composite wheel. In this regard, the engagement surface is located at least partially within the insert section of the attachment element (as discussed below), as taught in Applicant’s international patent publication No. WO2022 / 241510, the contents of which should be understood to be incorporated into this specification by this reference.

[0079] This recessed positioning (partial or full recess as discussed below) of the engagement surface of the arrangement enables the attachment arrangement to accommodate shorter elongate fasteners (wheel studs) compared to the arrangement taught in WO2013 / 000009A1 . This provides a smaller stack height (i.e. the height from the mid-point of the engagement portion of the fastening body to the back surface of the mount (typically the wheel mount) compared to where the engagement surface is located fully above the surface of the composite wheel in the bearing body.

[0096]

[0080] In these embodiments, the at least one engagement surface includes a distal end and said distal end of the engagement surface is preferably located axially away from the base of the bearing body - relative to the fastening axis - and between the base of the bearing body and the distal end of the insert section. Here, the engagement surface is located at least partially within the insert section of the attachment element. However, the location of the engagement surface within the attachment element can vary depending on the desired configuration and function of the attachment arrangement.

[0097]

[0081] In some embodiments, at least part of the least one engagement surface is located axially above the base of the bearing body relative to the fastening axis. In such embodiments, at least a part of the engagement surface may be located within the bearing body, and thus above the surface of the composite wheel surrounding that the attachment aperture. In most cases, that above surface portion of the engagement surface would only be an initial (top) section of the engagement surface, with a substantive portion of the engagement surface located in the insert section, and thus located axially below the base of the bearing body relative to the fastening axis. The distal end of the at least one engagement surface will therefore be located axially away from the base of the bearing body - relative to the fastening axis - and between the base of the bearing body and the distal end of the insert section.

[0098]

[0082] In other embodiments, the engagement surface is located fully below the base of the bearing body. For example, the at least one engagement surface can be located axially away from the base of the bearing body, and axially through and below the fastening aperture, relative to the fastening axis.

[0099]

[0083] In some embodiments, the at least one engagement surface is substantially located between the base of the bearing body and the distal end of the insert section. Here, the engagement surface may be substantially located within the insert section of the attachment element, and preferably the engagement surface will be located within the insert section. When located in the insert section, the engagement surface will be positioned between the base of the bearing body and the distal end of the insert section.

[0100] Materials

[0101]

[0084] The parts of the attachment arrangement of the various embodiments of the present invention, including the fastening body, the attachment element, the backing element and the like (where applicable in particular embodiments) can be constructed of any suitable material. In many instances the attachment arrangement will be metallic, for example formed from steel or other iron-based alloy, or aluminium or an aluminium based alloy. Depending on the metal, corrosion protection may be required. Low corrosion metals such as stainless steel or titanium may be used. Other metals may need more robust corrosion protection, for example, a corrosion protection coating applied to part or all of the metal components. Carbon steel may be used with corrosion protection such as painting or powder coating. Aluminium alloy can be protected for example using hard anodising according to military specification MIL-A-8625F. The attachment element may be made of any suitable material. In embodiments, the attachment element is made from aluminium, preferably a high performing grade of aluminium. In other embodiments, the attachment element is made from another metal for example, titanium, or steel. In other embodiments, the attachment element is made from a composite capable of withstanding the compressive force under the fastener body / bolthead. As noted above, the components, including the attachment element, may have any form of corrosion protective, or joint lubrication coatings such as anodising.

[0102]

[0085] The composite wheel of the present application can have any suitable composition. In exemplary embodiments, the composite wheel comprises a carbon fibre composite wheel. However, it should be appreciated that the composite wheel may be made from any composite material be it glass, aramid or carbon and with any resin type.

[0103] Composite Wheel Arrangement

[0104]

[0086] A second aspect of the present invention provides a composite wheel fitted with the attachment arrangement of the first aspect of the present invention. In embodiments, the composite wheel comprises a carbon fibre wheel. This arrangement includes the fastening body which includes the elongate fastener element or can be fastened to the elongate fastener element of a wheel mount of a vehicle. The fastening body has an engagement portion having a substantially complementary configuration to the engagement surface. In use, the engagement portion of the fastening body engages with the engagement surface when the fastening body fastens to the mount through the elongate fastener element to fasten the composite wheel between the bearing body and the wheel mount. As discussed above, the composite wheel typically comprises a vehicle wheel, preferably at least one of: an automotive wheel, or an aerospace wheel.

[0105]

[0087] Again, it should be appreciated that the substantially complementary configuration of the engagement surface and the engagement portion function to facilitate force transfer between the engagement surface and the engagement portion. Preferably, the substantially complementary configuration has cooperating shaped surfaces that engage together. However, it should be appreciated that in some embodiments, this may involve cooperating designs where only part of the engagement portion directly contacts the corresponding area on the engagement surface. In this sense, the engagement between the engagement surface and the engagement portion does not require all or substantially all of the engagement portion to contact the engagement surface.

[0106]

[0088] The attachment arrangement is preferably fitted to the composite wheel preloaded in tension between the at least one engagement surface and the base of the bearing body. The composite wheel preferably includes at least two fastening apertures, and the backing element includes at least two insert section apertures configured to cooperate with insert sections from respective engagement bodies inserted through each of the at least two fastening apertures.

[0089] The composite wheel fastened using the attachment arrangement can be any composite material in which compression joint damage can occur, for example, a fibre reinforced composite such as (but not limited to) a carbon fibre composite material or carbon / epoxy composite. It should however be understood that other types of composite materials other than carbon fibre and epoxy resin could be used in the composite wheels of the present invention which use the same joint. One preferred application is for attaching the composite wheel to a wheel mount, and more preferably one or more carbon fibre composite wheels. Another preferred application is for wheel-wheel attachment of a composite joint, such as in a joint between two wheel halves, such as a joint between the wheel halves that form an aerospace type wheel.

[0107] BRIEF DESCRIPTION OF THE DRAWINGS

[0108]

[0090] The present invention will now be described with reference to the figures of the accompanying drawings, which illustrate particular preferred embodiments of the present invention, wherein:

[0109]

[0091] Figure 1 provides a perspective construction view of an automotive carbon fibre wheel, wheel mount and wheel attachment arrangement which connects the wheel to the wheel mount according to a first embodiment of the present invention.

[0110]

[0092] Figure 2 provides an enlarged cross-sectional perspective view of a portion of the wheel attachment arrangement shown in Figure 1 .

[0111]

[0093] Figure 3 provides a front elevation cross-section of the attachment arrangement shown in Figure 2.

[0112]

[0094] Figure 3A provides a front elevation cross-section of a short-stud form of the attachment arrangement which connects the wheel to the wheel mount according to a second embodiment of the present invention.

[0095] Figure 4A provides an enlarged front elevation cross-section of the wheel attachment arrangement shown in Figures 2 and 3 providing an exaggerated view of the configuration of the engagement surface and base surface of the bearing body of the attachment element.

[0113]

[0096] Figure 4B provides an enlarged perspective cross-section of the wheel attachment arrangement shown in Figures 2 and 3 providing closer and again exaggerated view of the configuration of the engagement surface and base surface of the bearing body of the attachment element.

[0114]

[0097] Figure 5 provides the results of finite element modelling of the force transfer and loading of an attachment element where the bearing body has a flat engagement surface and flat base, showing (A) force loading on attachment element; and (B) force loading on the composite material around the relevant attachment aperture in the composite wheel.

[0115]

[0098] Figure 6 provides the results of finite element modelling of the force transfer and loading of an attachment element where the bearing body has a sloped engagement surface and sloped base according to an embodiment of the present invention, showing (A) force loading on attachment element; and (B) force loading on the composite material around the relevant attachment aperture in the composite wheel.

[0116]

[0099] Figure 7 provides a top perspective view of a second wheel attachment arrangement in accordance with the present invention that includes a shared bearing body comprising a single piece front plate.

[0117]

[0100] Figure 8 provides a cross-sectional perspective view of the wheel arrangement shown in Figure 7 illustrating the stacking arrangement of the bearing body and backing plate.

[0118]

[0101] Figure 8A provides a cross-sectional perspective view of a third wheel attachment arrangement illustrating a shared bearing plate to form an attachment arrangement similar to those shown in Figures 2 to 4B using an attachment element and wheel bolt as shown in those figures.

[0102] Figure 8B provides a cross-sectional perspective view of a third wheel attachment arrangement illustrating a shared bearing plate to form an attachment arrangement similar to those shown in Figures 3A using an attachment element and wheel bolt as shown in that figure.

[0119]

[0103] Figure 9 provides a perspective construction view of a two part aerospace composite wheel and one form of the wheel halves attachment arrangement which connects the two halves of this composite wheel together according to a third embodiment of the present invention.

[0120]

[0104] Figure 10 provides an enlarged cross-sectional perspective view of a portion of the wheel halves attachment arrangement shown in Figure 9.

[0121]

[0105] Figure 11 provides a front elevation cross-section of the wheel halves attachment arrangement shown in Figures 9 and 10.

[0122] DETAILED DESCRIPTION

[0123]

[0106] Figure 1 illustrates a carbon fibre composite wheel 10 which is attached to a wheel mount (or wheel hub) 12 through wheel studs 14 using an attachment arrangement 16 according to a first embodiment of the present invention. The illustrated attachment arrangement 16 comprises flat headed fastening nuts 18 (see more detail in Figures 2 and 3) which can be fastened onto the wheel studs 14, attachment elements 20 and a backing plate 22. A brake disc hat 12A is also included between the wheel mount 12 and the backing plate 22 which provides a solid mounting for a range of disc brake arrangements (not illustrated). For the purposes of this specification, the brake disc hat 12A can be considered to form part of the wheel mount 12.

[0124]

[0107] The illustrated composite wheel 10 is a one-piece carbon fibre wheel, for example as described in International Patent Publication W02010 / 025495A1 and International Patent Publication No. WO2019 / 033169A1 , the contents of which should be understood to be incorporated into this specification by this reference. The hub portion 23 of the illustrated composite wheel 10 includes six attachment apertures 24 through which the wheels studs 14 of the wheel mount 12 are inserted when the wheel 10 is mounted on the wheel mount 12. Each of the wheel studs 14 are an elongate externally threaded pin having a complementary thread to a threaded internal bore 26 (Figure 3) of each of the fastening nuts 18. As shown best in Figure 3, each of the wheel studs 14 comprise an elongate bolt 14A that extends through the wheel mount 12 and the adjoining brake disc hat 12A, and is retained in part by fastener head 14B.

[0125]

[0108] Whilst the illustrated wheel has six attachment apertures 24, it should be appreciated that a composite wheel using the attachment arrangement of the present invention may have any number of attachment apertures, for example one (center lock), two, three, four, five, six or more.

[0126]

[0109] As best shown in Figures 2 and 3, each fastening nut 18 is a cylindrical cap including a base 28 which annularly extends around the internal bore 26. The internal bore 26 includes a central fastener axis F (Figure 3). The base 28 of each fastening nut 18 provides a substantially flat engagement portion 36 which is substantially perpendicular to central fastener axis F and which extends from the edge of the internal bore 26 (Figure 3) to the outer radial side 32 of the fastening nut 18.

[0127]

[0110] A flat / planar washer 19 is also provided which is fastened between the base 28 of each fastening nut 18 and the engagement portion 36 thereof, and an engagement surface 30 of the bearing body 21 .

[0128]

[0111] As best illustrated in Figures 2 and 3, the attachment element 20 comprises two main sections:

[0129] (A) A bearing body 21 which comprises a generally toroid shaped head 38 - similar to a fastening washer; and

[0130] (B) an axially extending cylindrical insert section (sleeve) 40.

[0131]

[0112] The bearing body 21 and insert section 40 are preferably integrally formed from a single piece of material, such as metal, which could be cast, forged or machined from a billet or the like.

[0132]

[0113] A fastening aperture 42 extends axially through length of the attachment element 20. The fastening aperture 42 also includes a central fastening axis X. The fastening axis X of the fastening aperture 42 and the fastener axis F of the internal bore 26 of the fastening nut 18 are aligned when the bearing body 21 and nut are in use, as shown in Figure 3. In use, the fastening aperture 42 receives a wheel stud 14 which extends from the wheel mount 12 (Figure 1 ).

[0133]

[0114] The bearing body 21 is used to distribute a clamping force across the surface 47 of the composite wheel 10 around the attachment aperture 24. To achieve this, the bearing body 21 includes a base 44 configured to face and abut the surface 45 of the composite wheel 10 about the attachment aperture 24. The head 38 of the bearing body 21 is therefore configured to provide an increased clamping contact area with the load transfer zone 45 of the surface 47 of the composite wheel 10 surrounding the attachment aperture 24 and thereby increase the area through which the clamping force is applied to that area. The details of this contact will be described in more detail below. It should be appreciated that in other embodiments, that the base 44 of the bearing body 21 may operatively engage the contact surface of the composite wheel about the attachment aperture 24 through an intermediary body, for example a washer or other member such as a shared bearing plate. It should be understood that such indirect contact through such an intermediary body would still function within the described scope of the present invention, but simply with the further inclusion of that intermediary body.

[0134]

[0115] The top of bearing body 21 includes an engagement surface 30 that is configured engage with the engagement portion 36 of the fastening nut 18 through washer 19. As illustrated in Figure 3A (and described in more detail below), this engagement may be through a recess, for example a nut aperture comprises a circular or polygonal shaped recess sized to accommodate the fastening nut, with some clearance, to allow the fastening nut to be manipulated in that recess, as taught in Applicant’s international patent publication No. WO2022 / 241510, the contents of which should be understood to be incorporated into this specification by this reference. It should also be understood that in other embodiments, the engagement surface 30 of bearing body 21 can directly engage with the engagement portion 36 of the fastening nut 18, i.e. without the need for the use of a washer 19.

[0116] The insert section 40 functions to distribute the load away from the center of the fastening aperture 42 and away from the walls of fastening aperture 42. In some embodiments, the insert section 40 can also be designed to transfer the clamping force from the engagement surface 30 of the bearing body 21 and base 44 and through the insert section 40.

[0135]

[0117] The insert section 40 extends axially outwardly from the base 44 of the head 38 of the bearing body 21 about the fastening aperture 42. The insert section 40 is configured to extend into an attachment aperture 24 of the composite wheel 10. The radial cross-section of body 50 of the insert section 40 is circular. Furthermore, the radial width of the body 50 of the insert section 40 is smaller than the radial width of the attachment aperture 24. Whilst not illustrated, this can form a radial gap between the outside of the body 50 of the insert section 40 and the internal sides of attachment aperture 24 in the composite wheel 10. This reduces the possibility of the insert section 40 transferring some of the clamping load to the walls of the attachment aperture 24 and also provides clearance for a degree of expansion of the insert section 40 within the attachment aperture 24.

[0136]

[0118] Whilst not essential to the load distribution function of the attachment element, the distal end 52 of the insert section 40 can include a recess 52A onto which a clip, for example a circlip 52B can be fastened as a retention arrangement to prevent the attachment element 20 from falling out from the attachment aperture 24, as shown in Figure 3. It should be appreciated that other arrangements could equally be used, for example an interference fit, and other types of projections and clips. In other embodiments (not illustrated), the retention formation can be formed at the distal end 52 of the insert section 40 through deformation of the distal end 52 for example to form a rolled edge after the distal end 52 of the insert section 40 is inserted through the attachment aperture 24, so that it has a greater size than the attachment aperture 24.

[0137]

[0119] The thickness and radial width of the insert section 40 is sufficient to provide sufficient material to enable force transfer from the engagement surface 30 to the base 44 of the bearing body 21 . Additionally, the distal end 52 of the insert section 40 is positioned at a spaced apart location from the surface of the wheel mount 12 and the adjoining brake disc hat 12A (as illustrated).

[0138]

[0120] In the illustrated embodiment, the engagement surface 30 is located on the top surface of the bearing body 21 . However, it should be appreciated that in other embodiments this could be formed in an inner / internal surface of the bearing body 20 and / or the insert section 40. The engagement surface 30 has a substantially complementary configuration the base engagement portion 36 of the fastening nut 18. In use, the engagement portion 36 of the fastening nut 18 engages with the engagement surface 30 of the bearing body 21 through washer 19 when the fastening nut 18 is assembled on a wheel stud 14 to fasten the composite wheel 10 between the bearing body 21 and the wheel mount 12. Again, in other embodiments, the engagement surface 30 of bearing body 21 can directly engage with the engagement portion 36 of the fastening nut 18.

[0139]

[0121] As best shown in Figures 4A and 4B, the engagement surface 30 and the base 44 of the bearing body 21 are not perpendicular to fastening axis X, and are not configured to be parallel with each other, but rather are configured to converge towards each other closest to the attachment aperture 24 (or the fastening aperture 42 shown in Figures 4A and 4B). It should be appreciated that Figure 4A and 4B provide an exaggerated view of the configuration of the engagement surface 30 and base surface 44 of the bearing body 21 of the attachment element 20, where the angle and curve have been exaggerated for ease of illustration, compared to the actual angle and curve as shown in Figures 2 and 3.

[0140]

[0122] In the embodiment illustrated in Figures 4A and 4B, the base 44 of the bearing body 21 is a sloped and curved surface which extends upwardly (at angle a above the perpendicular axis) relative to the fastening axis X from a location that is spaced away from the insert section 40, in this case the distal outer end 44A, to an insert end 44B proximate to the insert section 40. The actual angle or curved shape of the base surface depends on various factors but can comprise a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees (again it should be appreciated that this angle has been exaggerated in Figures 4A and 4B for ease of reference and illustrate purposes). Again, in some embodiments, the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 5 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. It should again be appreciated that where the attachment arrangement comprises a centre lock wheel attachment arrangement, the base of the bearing body may comprise a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 1 to 7 degrees, more preferably 2 to 6 degrees, yet more preferably from 3 to 5 degrees, for example around 4.5 degrees.

[0141]

[0123] As explained previously, this slope on the base 44 has been configured to drive initial engagement between the base 44 of and the contact surface 25 thereof of the composite wheel 10 is spaced away from the insert section 40, and by association is spaced away from the attachment aperture 24 toward the distal end 44A of the base 44. The remaining sections of the base 44 are initially spaced away from the contact surface 25 in this initial contact. As the fastening body 18 is tightened on the elongate fastener 14 about the fastening axis X, the central region 44C of the base 44 pulls down onto the contact surface 25 of the composite wheel 10 creating a more uniform pressure distribution on that contact surface 25. It should be appreciated that the achievement of uniform surface pressure on the contact surface 25 of the composite wheel 10 around the attachment apertures 24 depends on various input parameters for example stiffness of laminate, type of fastener / bolt, configuration of the base 44 of the bearing body 21 , configuration of the engagement surface 30, fastening torque, and the like.

[0142]

[0124] As best shown in Figure 4A, the base 44 of the bearing body 21 has a slight convex profile providing an initial engagement surface for a contact surface of the composite wheel 10 about the distal outer end 44A or an outer section of the base 44. The lowest point of the curve relative to the fastening axis X provides that initial engagement surface / point.

[0143]

[0125] As best shown in Figure 4A, the engagement surface 30 at the top of the bearing body 21 also comprises a sloped curved surface which extends and is angled downwardly (at angle I3> below the perpendicular axis) relative to the fastening axis X from a distal outer end 30A to a fastening end 30B proximate to the fastening aperture 42. The slope is designed to enable the engagement portion 36 of the fastening nut 18 to contact the outer perimeter of the engagement surface 30 (through the washer 19) first transferring force through the insert / washer 19 to the distal outer end 44A (outer perimeter) of the base 44 of the bearing body 21 to the contact surface 25 of the composite wheel 10 first. As the fastening nut 18 is tightened on bolt 14, more of the flat surface of the engagement portion 36 of the fastening nut 18 contacts the top engagement surface (through washer 19), and more of the base 44 contacts the contact surface 25. Thus when the joint is tightened, the force is progressively transferred towards the attachment aperture 24. The outcome of this behaviour is that when full bolt tension is reached there is a substantially uniform distribution of pressure on the contact surface 25 around the attachment aperture 24.

[0144]

[0126] Like the base 44 of the bearing body 21 , the actual angle of engagement surface depends on various factors, but typically comprises a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 0.5 to 1 .5 degrees, more preferably 0.77 to 1 degrees (again it should be appreciated that this angle has been exaggerated in Figures 4A and 4B for ease of reference and illustrate purposes). In embodiments, the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 5 degrees, preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees. Again, it should be appreciated that where the attachment arrangement comprises a centre lock wheel attachment arrangement, the base of the bearing body may comprise a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 1 to 7 degrees, more preferably 2 to 6 degrees, yet more preferably from 3 to 5 degrees, for example around 4.5 degrees.

[0145]

[0127] As best shown in Figure 4A, the engagement surface 30 comprises a slight convex profile providing an initial engagement surface for the engagement portion 30 of the fastening bolt 18 about the distal outer end or an outer section of the engagement surface 36. The curve / convexity on the engagement surface is to drive initial contact and load from the bolt 18 toward the outer edge 30A of the engagement surface 30 during initial clamp-up.

[0146]

[0128] The attachment element 20 is configured to project the compressive force from that clamping engagement outwards from the engagement surface 30 and axially (relative to fastening axis X) back up the insert section 40, and to the base 44 of the bearing body 21 . This indirectly creates a compression force between the base 44 of the bearing body 21 and the backing plate 22, sandwiching the material of the composite wheel 10 together between the base 44 of the bearing body 21 and the backing plate 22 thereby securely fastening the wheel 10 onto the wheel mount 12. Tightening of the fastening nut 18 on the wheel stud 14 engages the engagement portion 36 of the fastening nut 18 onto the engagement surface 30 creating a compression force on the engagement surface 36, which is transferred into the adjoining portion of the insert section 40. This in turn creates a tension force between the engagement surface 30 and the bearing body 21 , which in turn applies a compression force from the base 44 of the bearing body 21 onto the surface 47 of the composite wheel 10 around the attachment aperture 24. The transfer of forces from the engagement surface 30 through the bearing body 21 ensures that the applied force is distributed away from the edge of the attachment aperture 24 and is more evenly distributed across the composite surface in a load transfer zone 45 and then on and through the composite structure around the attachment aperture 24.

[0147]

[0129] The base 44 of the bearing body 21 is configured with sufficient surface area sufficient area under the bearing body 21 to reduce the compressive load on the laminate to a threshold load of less than 150 MPa, preferably less than 100 MPa. It should be appreciated that this threshold load is governed by material selection, joint efficiency, bolt cone angle / diameter / material, bolt torque or the like. The outcome is that for any operational environment, the laminate compressive force should not exceed a value which triggers an unacceptable bolt tension reduction. This can be seen in Figures 5 and 6, which provide a comparison of finite element analysis of loading conditions on a flat headed fastener engaging with an attachment element 120 having a configuration according to an embodiment of the present invention (Figure 6) compared to an attachment element 120A which has a flat base and flat engagement surface, each of which are orientated perpendicular to the fastening axis X (Figure 5).

[0148]

[0130] Firstly, looking at Figure 5, this Figure provides the results of finite element modelling of the force transfer and loading of an attachment element 120A where the bearing body 121 A has a flat (horizontal) engagement surface 130A and a flat base 144A. Figure 5(A) force loading on attachment element 120A showing that there is a yielded region 180A between the bearing body 121 A and the insert section 140A. The loading on the contact area 125A of the composite material in the wheel around the relevant attachment aperture in the composite wheel 110 (see Figure 5(B) shows that there is a high concentration of load 181 A at the edge of the attachment aperture 124A with stress exceeding 300MPa. This clearly exceeds the ideal threshold load. Thus, this form of attachment element 120A shows yielding in the insert 120A and unacceptable laminate compressive forces from bolt head pulling down, distorting the insert 120A. This would result in the visco-elastic composite material would relax under the excessive compressive force and the result would be a loss of clamp force, allowing movement in the joint creating wear, friction, and / or separation. The joint design should ensure that the wheel remain fastened to the mounting element, such as a wheel mount.

[0149]

[0131] In comparison, Figure 6 provides the results of finite element modelling of the force transfer and loading of an attachment element where the bearing body has a sloped engagement surface and sloped base according to an embodiment of the present invention. Compared to Figure 5, Figures 6(A) and 6(B) show significantly improved joint behaviour, with around 70% reduction in laminate compression force in the contact area 125 around the attachment aperture 124, and no yield zones in the attachment element 120 in the bearing body 121 or the insert section 140. As shown in Figure 6(B) there is an increasingly uniform pressure distribution across the laminate, with peak stresses limited to around 100 MPa in only a small area. This satisfies the ideal threshold load conditions.

[0150]

[0132] Finally, it should be appreciated that the attachment element 20 can be sized for each unique wheel design and application taking into account variables such as but not limited to; - bolt length which affects stack height,

[0151] - bolt / washer contact diameters,

[0152] - washer shape (i.e. flat or conical)

[0153] - composite material laminate thickness,

[0154] - materials,

[0155] - bolt torque, and hence tension,

[0156] - fatigue and static loading requirements,

[0157] - environmental condition during storage and use.

[0158]

[0133] As best shown in Figures 1 and 3, the backing plate 22 is designed to be inserted between the wheel mount 12 and the composite wheel 10. The illustrated backing plate 22 is a flat toroid plate which includes six annularly spaced apart insert section apertures 54. The backing plate 22 provides a large surface on the opposite side of the attachment aperture 24 to the bearing body 21 against which the composite wheel 10 can be clamped by a compression force. The illustrated insert section apertures 54 have a generally circular shape designed to receive but not interlock with the distal end 52 of the insert section 40 section of the bearing body 21. Rotation of the bearing body 21 can be prevented by any suitable means. In some embodiments, an insert rod (not illustrated) can be inserted within a recess in the base 44 of the bearing body 21 , and projecting axially out therefrom, which is received and seated in a complementary recess in the surface of the composite wheel 10. Alternatively, the distal end 52 of each insert section 40 can be configured to be received in a complementary shaped insert section aperture formed in the backing plate 22, for example a complementary hexagonal shape. This complementary shape substantially prevents axial rotation of the insert section 40 relative to the wheel mount 12.

[0159]

[0134] The insert section 40 of the bearing body 21 is preferably not bonded to the composite wheel 10 in any way. This allows the insert section 40 to slide relative to the attachment aperture 24 in the composite wheel 10.

[0160]

[0135] In some embodiments (not illustrated), the backing plate 22 includes an insert section aperture that is sized to allow at least a portion of the distal end 52 of the insert section 40 to move therethrough. In some arrangements, the clearance can be tailored to produce a sliding fit between the insert section 40 and the backing plate 22 allowing the distal end 52 of the insert section 40 to slide through the insert section aperture when the attachment arrangement 16 is compressed. This reduces the possibility of the insert section 40 contacting the mount 12 and transferring some of the clamping load to the mount 12 or radially within the attachment aperture 24 or insert section aperture. However, it should be understood that the distal end 52 of the insert section 40 is preferably designed to not directly engage or contact (radially or axially relative to axis X-X) any part of the wheel mount 12 (Figure 1 ) or the backing plate 22.

[0161]

[0136] Clearance can also be provided between this distal end 52 of the insert section 40 and backing plate 22 to ensure clamping load is transmitted from the engagement surface 30 through the carbon composite laminate 11 of composite wheel 10 and backing plate 22, and into the vehicle wheel mount (not illustrated).

[0162]

[0137] As discussed briefly above, the bearing body 21 D can be configured to receive the fastening nut 18D therein where a shorter wheel stud 14D may be required, thereby enabling the engagement portion 36D of the fastening nut 18D to engage with an engagement surface 30D (through washer 19D) located within the bearing body 21 D and / or insert section 40D of the attachment arrangement 16D. An example of one of these types of embodiments is illustrated in Figure 3A. It should be appreciated that this embodiment has all the same general features as discussed for the embodiment illustrated in Figures 1 to 3, but in this embodiment the engagement surface 30D is positioned within the bearing body 21 D, below the base 44D of the bearing body 21 D and below the top surface level of the composite wheel 10D. Again, the engagement portion 36D of the fastening nut 18D is configured to engage with engagement surface 30D through washer 19D.

[0163]

[0138] In order to accommodate the fastening nut 18D, the bearing body 21 D includes a body aperture 23D sized to receive the fastening nut 18D. The body aperture 23D comprises a circular or polygonal shaped recess which steps into the fastening aperture 42D. In the illustrated embodiment, the body aperture 23D extends through the bearing body 21 D and into the insert section 40D of the attachment element 16D. Thus, part of the insert section 40D is also configured to receive a portion of the fastening nut 18D. This configuration results in the insert section 40D having a first section 24D having a first internal diameter to receive the fastening nut 18D, and a second section 24E having a second internal diameter sized so that that the fastening nut 18D cannot fully extend therethrough (and also thereby providing the engagement surface 30D), and also through which the wheel stud 14D can extend. In this regard, the engagement surface 30D is located at least partially within the insert section 40D of the attachment element 16D.

[0164]

[0139] This recessed positioning (partial or full recess as discussed below) of the engagement surface 30D of the arrangement enables the attachment arrangement 16D to accommodate shorter wheel studs 14D compared to the arrangement shown in Figure 3. This provides a smaller stack height (i.e. the height from the mid-point of the engagement portion 36D of the fastening nut 18D to the back surface of the wheel mount 12D compared to where the engagement surface 30D is located fully above the surface of the composite wheel 10D in the bearing body 21 D (for example as shown in Figure 3). As illustrated in Figure 3A, the engagement surface 30A located axially away from the base of the bearing body 21 D - relative to the fastening axis X-X - and between the base 44D of the bearing body 21 D and the distal end 24F of the insert section 40D. However, the location of the engagement surface 30D within the attachment element 20D can vary depending on the desired configuration and function of the attachment arrangement, and therefore may be for example higher within the insert section 40D relative to the fastening axis X-X, or fully within the bearing body 21 D in other examples. For example, in some embodiments, at least part of the engagement surface 30D may be located axially above the base 44D of the bearing body 21 D relative to the fastening axis X-X. In such embodiments, at least a part of the engagement surface 30D may be located within the bearing body 21 D, and thus above the surface of the composite wheel 10D surrounding that the attachment aperture.

[0165]

[0140] Apart from the recessed location of the engagement surface 30D and the fastening nut 18D within the bearing body 21 D and / or the insert section 40D, the attachment arrangement 16D and associated attachment element 20D operates in a similar manner as described in relation to the embodiment illustrated and described in relation to Figures 1 , 2 and 3. Again, the base 44D of the bearing body 21 D comprises a contact surface 45D configured to abut the contact surface 45D of the composite wheel 10D about the attachment aperture 24D, or operatively engage the contact surface 45D of the composite wheel 10D through an intermediary body, for example a washer or other member such as a shared bearing plate, in embodiments where that may be used. In this respect, the engagement surface 30D is at angle a and the base 44D of the bearing body 21 D is at angle I3> to the horizontal axis (i.e. axis perpendicular to the fastening axis X- X) and are therefore not perpendicular to the fastening axis X-X following what is shown and described in relation to Figures 4A and 4B. The description of this arrangement and functionality therefore equally applies to the embodiment illustrated in Figure 3A.

[0166]

[0141] Figure 7 and 8 illustrate an embodiment of the attachment arrangement 416 according to the present invention that includes a shared bearing body 321.

[0167]

[0142] A number of the features of the attachment arrangement 316 shown in Figure 7 and 8 are the same as those shown and described in relation to the embodiment shown in Figures 1 to 3, 4A and 4B. Like features in Figure 7 and 8 have therefore been provided with the same reference numerals as shown in Figures 1 to 3, 4A and 4B PLUS 300. It should be understood that the above description of the operation of the attachment arrangement 16 shown in Figures 1 to 3, 4A and 4B equally applies to this embodiment, with the exception of the configuration of the bearing body 321 and insert section (sleeve) 340.

[0168]

[0143] As best illustrated in Figures 7 and 8, the attachment element 320 comprises two main sections:

[0169] (A) the bearing body 321 which comprises a single piece front plate extending over and around each of the attachment apertures 324 of the composite wheel 310; and

[0170] (B) a plurality of axially extending cylindrical insert sections 340 which are configured to extend into each attachment aperture 324.

[0144] The attachment element 320 also includes fastening apertures 342 for each attachment aperture 324 in the composite wheel 310.

[0171]

[0145] The bearing body 321 and each insert section 340 of the attachment element 320 are preferably integrally formed from a single piece of material, such as metal, which could be cast, forged or machined from billet.

[0172]

[0146] As with the previous embodiments, a fastening aperture 342 extends axially through each insert section 340 about a central fastening axis X (Figure 8). The fastening axis X of the fastening aperture 342 and internal bore 325 of the fastening nut 318 are aligned in use. In use, each fastening aperture 342 receives a wheel stud 314 of the wheel mount (for example wheel studs 14 of wheel mount 12 in Figure 1 ).

[0173]

[0147] In this embodiment, the bearing body 321 comprises a top plate configured to extend over the surface 347 of the composite wheel 310 between and around each of the attachment apertures 324. The bearing body 321 is configured as a shared body that provides an increased clamping contact area 345 with the surface 347 of the composite wheel 310 over the surface 325 of the composite wheel 310 around each of the attachment apertures 324. Like the previous embodiments, the base 343 of the bearing body provides an angled surface configured to face and abut the surface of the composite wheel 10 about each attachment aperture 324 - but in this case with that base surface 344 extending between and about each attachment aperture 324, with the angled surface of the base 344 adapted to fit that configuration, configured to move between an initial contact position, where initial engagement between the base 344 of and the contact surface 325 thereof of the composite wheel 310 is spaced away from the insert section 340 and more importantly spaced away from the attachment aperture 324. The remaining sections of the base 344 closer to the attachment aperture 324 are initially spaced away from the contact surface 325 in this initial contact. As the fastening body 318 is tightened on the elongate fastener about the fastening axis X, a region of the base 344 between that spaced away position and the attachment aperture 324 pulls down onto the contact surface 325 of the composite wheel 310 creating a more uniform pressure distribution on that contact surface 325.

[0174]

[0148] In this embodiment, the shared bearing body 321 includes six recessed portions in each fastening aperture 342 comprising nut apertures 327. The nut apertures 327 comprises a circular or polygonal shaped recesses sized to accommodate the fastening nut 318, with some clearance, to allow the fastening nut 318 to be manipulated in that recess. The nut aperture 327 leads directly into the insert section 340 of the shared bearing body 321 .

[0175]

[0149] The engagement surface 336 is located at the base of the nut apertures 327, and as in the previous embodiment also comprise sloped curved surface which extends and is angled downwardly relative to the fastening axis X from a distal outer end 330A to an fastening end 330B proximate to the fastening aperture 342, and provide the same function as previously described.

[0176]

[0150] As best illustrated in Figure 8, each insert section 340 extends axially outwardly from the base 344 of the bearing body 321 about the fastening aperture 342 into and through the respective attachment apertures 324 of the composite wheel 310. The radial cross-section of the insert section 340 is circular, and preferably has a radial width smaller than the radial width of the attachment aperture 322, similar as described for the previous embodiment. The insert section 340 of the bearing body 321 is preferably not bonded to the composite wheel 310 in any way. This allows the insert section 340 to slide relative to the attachment aperture 324 in the composite wheel 310.

[0177]

[0151] Again, the transfer of forces from the engagement surface 330 through the bearing body 321 ensures that the force is distributed away from the edge of the attachment aperture 324 and is more evenly distributed across the composite surface 347 and then on and through the composite structure around the attachment aperture 324. For this embodiment, the shared nature of the bearing body 321 provides even greater distribution of those forces over the across the composite surface 347.

[0152] As best shown in Figure 8, a backing plate 422 is designed to be inserted between the wheel mount 312 and the composite wheel 310. The illustrated backing plate 322 is a flat toroid shaped plate which includes six annularly spaced apart insert section apertures 354 - corresponding with the number of attachment apertures 324 in the composite wheel - through which the wheel stud 314 extends. The backing plate 322 provides a large surface on the opposite side of the attachment apertures 324 to the bearing body 321 against which the composite wheel 310 can be clamped. Like the previous embodiment, the distal end 352 of the insert section 340 does not directly engage (radially or axially relative to axis X-X) any part of the wheel mount 312 or the backing plate 322.

[0178]

[0153] Whilst not illustrated, a fastener such as a shoulder bolt can be fastened in a recess in the surface 327 of the composite wheel 310 to loosely hold the shared bearing body 321 and the backing plate 322 together though the carbon fibre wheel 310. This also prevents rotation of the bearing body 321. Nevertheless, it should be appreciated that equally an alternate retention feature, for example a circlip or other fastener arrangement provided on the distal end of each insert section 340 or similar could equally be used to perform this function. Here a further section may axially extend from the distal end 352 of the insert section 440 through the respective insert section aperture 354, onto which the fastener arrangement is attached. Similarly, embodiments of the insert section 340 may include a sleeve or similar extension section that axially extends from the distal end 352 of the insert section 340 through the respective insert section aperture 354.

[0179]

[0154] When fitted to a composite wheel 10 (for example as shown in Figure 1), the attachment arrangements 16, 316 are preloaded in tension between the annular engagement surface 30, 330 of the arrangement 16, 316 and the base 44, 344 of the bearing body 21 , 321 (and the load transfer zone 45, 345 of the surface of the composite wheel 10 around the attachment aperture 24, 324 through tightening of the fastening nut 18 on wheel studs 14, 314. This also preloads compression between the base 44, 344 of the bearing body 21 , 321 and the surface of the composite wheel 10 around the attachment aperture 24, 324.

[0155] Figure 8A provides an alternate shared front plate embodiment to that illustrated in Figures 7 and 8, where a shared bearing plate 380X is used to extend over the surface of the composite wheel 31 OX between and around attachment apertures 324X. The bearing plate 380X provides a shared body that provides an increased clamping contact area with the surface of the composite wheel 31 OX around each of the attachment apertures 324X. The attachment arrangement follows the configuration as described for the first aspect of the present invention illustrated and described in Figures 2 to 4B, with this intermediary bearing plate between the head of the bearing body 321 X and the composite wheel 31 OX. Accordingly, a number of the features of the attachment arrangement shown in Figure 8A are the same as those shown and described in relation to the embodiment shown in Figures 1 to 3, 4A and 4B. Like features in Figure 8A have therefore been provided with the same reference numerals as shown in Figures 1 to 3, 4A and 4 PLUS 300X. It should be understood that the above description of the operation of the attachment arrangement 16 shown in Figures 1 to 3, 4A and 4B equally applies to this embodiment, with the exception that the bearing body 321 engages the composite wheel 310 through bearing plate 380X.

[0180]

[0156] Figure 8B provides yet a further an alternate shared front plate embodiment to that illustrated in Figures 7 and 8, where a shared bearing plate 380Y is used to extend over the surface of the composite wheel 310Y between and around attachment apertures 324Y. In this embodiment, the shared bearing plate 380Y is configured to accommodate shorter wheel stud 14D lengths compared to those shown in Figure 8 and 8A, and thus take a similar configuration to that illustrated and described in relation to Figure 3A. Again, the bearing plate 380Y provides a shared body that provides an increased clamping contact area with the surface of the composite wheel 310Y around each of the attachment apertures 324Y. The attachment arrangement follows the configuration as described for the aspect of the present invention illustrated and described in Figure 3A, with this intermediary bearing plate 380X providing the function of the bearing body 321 Y. Accordingly, a number of the features of the attachment arrangement shown in Figure 8A are the same as those shown and described in relation to the embodiment shown in Figure 3A. Like features in Figure 8A have therefore been provided with the same reference numerals as shown in Figures 3A PLUS 300Y. It should be understood that the above description of the operation of the attachment arrangement 16A shown in Figures 3 equally applies to this embodiment, with the exception that the bearing body 321 Y engages the composite wheel 31 OY through bearing plate 380Y. Again, it should be understood that brake disc hat 312Z is also included between the wheel mount 312Y and the backing plate 322Y which provides a solid mounting for a range of disc brake arrangements (not illustrated). For the purposes of this specification, the brake disc hat 312Z can be considered to form part of the wheel mount 312Y.

[0181]

[0157] The aerospace industry, like the industrial transport industry, in all known instances, utilises two wheel halves and fastens these together through the centre aperture of the tyre. This joint then is required to remain fastened together in order to retain the tyre pressure and provide adequate transfer of loads from the tyre contact patch to the axle / vehicle. Figures 9 to 11 illustrates an embodiment of the attachment arrangement 416 according to the present invention that uses a fastening bolt 414 with flat bolt head 414B and a flat headed fastening nut 418 to join two complementary wheel halves that are joined to form a composite wheel 400. One exemplary application of this embodiment is in forming aerospace wheels, for example composite wheels used on an aircraft, which will now be described. However, it should be appreciated that this embodiment could be used to join number of parts or sections between a section of a composite wheel and another element, for example another composite / carbon fibre element.

[0182]

[0158] A number of features of the attachment element 420 shown in Figures 9 to 11 are the same as those shown and described in relation to the embodiment shown in Figures 1 to 3, 4A and 4B. Like features in Figures 9 to 11 have therefore been provided with the same reference numerals as shown in Figures 1 to 3, 4A and 4B PLUS 400. It should be understood that the preceding description of the operation of the attachment arrangement 16 shown in Figures 1 to 3, 4A and 4B equally applies to this embodiment, with the exception that the attachment arrangement 416 the joint is not primarily for wheel to vehicle attachment, but for wheel-wheel attachment of a composite joint. In this sense, the attachment arrangement is not used to fasten a composite wheel to a wheel mount, but rather comprises two attachment arrangements that are placed in separate wheel halves 400A and 400B and are used to interconnect those wheel halves. Nevertheless, each attachment element 420 is formed from bearing body 421 and insert section 440 as previously described for the embodiment shown and describe in relation to Figures 1 to 4 and has the same features and function as previously described which interact with the wheel bolt 418 and flat headed fastening body (bolt head 414B and fastening nut 418) as previously described.

[0183]

[0159] Referring firstly to Figure 9, one embodiment of this two part aerospace carbon fibre composite wheel 410 is shown. The wheel 410 comprises two mirrored wheel halves 410A, 41 OB which are attached together using an attachment arrangement 416 according to a third embodiment of the present invention. The illustrated attachment arrangement 416 comprises flat headed fastening bolt 414, fastening nut 418, flat washers 419 (see more detail in Figures 9 and 10) which are inserted through attachment elements 420A and 420B which sit in the attachment apertures 424.

[0184]

[0160] The illustrated composite wheel halves 410A and 410B are formed as a one-piece carbon fibre wheel half, for example as described in International Patent Publication W02010 / 025495A1 and International Patent Publication No. WO201 9 / 033169A1 , the contents of which should be understood to be incorporated into this specification by this reference. The hub portion 423 of each the illustrated composite wheel halves 410A and 410B includes eight attachment apertures 424 through which the flat headed fastening bolt 414. Each of the fastening bolt 414 are an elongate externally threaded bolt having a complementary thread to a threaded internal bore 426 (Figure 11 ) of each of the fastening nuts 418. As shown best in Figure 3, each of the fastening bolt 414 comprise an elongate threaded bolt shaft 414B that extends through each attachment aperture 424 of the wheel halves 410A, 410B, and is retained in part by fastener head 314B. Each fastening nut 418 and bolt head 414B has a base 428 which annularly extends around the internal bore 426. The internal bore 426 includes a central fastener axis F (Figure 11 ). The base 428 of each fastening nut 418 and bolt head 414B provides a substantially flat engagement portion 436 which is substantially perpendicular to central fastener axis F and which extends from the outer edge of the internal bore 426 (Figure 3) to the outer radial side of the fastening nut 318, and from the outer surface of the bolt shaft 414B to the outer radial side of the bolt head 414B, in a similar manner as previously described for the first embodiment.

[0185]

[0161] Flat / planar washers 419A, 419B are also provided which are fastened between the base of each fastening nut 418 and the engagement portion 436 thereof, and an engagement surface 430 of the relevant bearing body 421 . It should be understood that in other embodiments, the engagement surface 430 of bearing body 421 can directly engage with the engagement portion 436 of the fastening nut 418, i.e. without the need for the use of a washer 419A, 419B.

[0186]

[0162] Whilst the illustrated wheel has eight attachment apertures 424, it should be appreciated that a two part composite wheel attached together using the attachment arrangement of this embodiment of the present invention may have any number of attachment apertures, for example four, five, six, eight, ten or more.

[0187]

[0163] As best illustrated in Figures 10 and 11 the attachment elements 420A and 420B comprises the same configuration as described in relation to the first embodiment described in relation to Figures 1 to 4. Again, the attachment elements 420A and 420B two main sections:

[0188] (A) A bearing body 421 which comprises a generally toroid shaped head 438; and

[0189] (B) an axially extending cylindrical insert section (sleeve) 440.

[0190]

[0164] Each bearing body 421 is configured and functions the same as previously described in relation to the first embodiment. Each insert section 440 has a similar configuration, but unlike the previously described automotive solutions, the insert sections 440 are designed to not extend beyond the mating surfaces of the laminates of each wheel half 410A, 410B (see Figures 10 and 11 ). The insert sections 440 are configured to terminate within the attachment aperture 324 of the respective composite wheel halves 41 OA, 41 OB in which that attachment element 420 is inserted. The illustrated insert sections 440 of each attachment element 420A, 420B is configured with a distal end 452 that is spaced away from the distal end 452 of the opposing insert section 420B, 420A.

[0191]

[0165] Thus, in these aerospace wheel embodiments (shown in Figures 9 to 11 ), the attachment arrangement 416 uses two attachment elements 420A 420B, positioned on opposite ends of the fastening bolt 414 and opposite sides of the joint between the two wheel halves 41 OA, 41 OB. There is a common through-hole through the joint laminate for each attachment element. The attachment arrangement 416 therefore comprises: fastening bolt 414 with flat bolt head 414B and cooperating flat headed fastening nut 418; washers 419A, 419B which are fastened between the base of each fastening nut 418 and the engagement portion 436 thereof, and an engagement surface 430 of the relevant bearing body 421 ; and two attachment elements 420A 420B, each insert 420A 420B being associated with one of the flat bolt head 414B or fastening nut 418 (the two fastening bodies).

[0192]

[0166] As shown in Figures 10 and 11 , each attachment element 420A 420B, is inserted into the relevant attachment aperture 424A, 424B, the two wheel halves 41 OA and 41 OB are positioned together with the relevant attachment apertures 424A, 424B of the two wheel halves aligned. Each fastening bolt 414 is then inserted through the aligned attachment apertures 424A, 424B (see Figure 11 ), with the washers positioned as shown in Figures 10 and 11 , and fastening nut 418 is then attached. The whole system is tightened. The sloped surfaces of the base 444 of each bearing body 421 and the engagement surface 430 of each bearing body 421 function as previously described for the first embodiment when engaged with the contact surface 425 of the composite wheel and the engagement portion 436 (though washer 419A or 419B) of the bolt head 414B or fastening nut 418 (whichever is associated with that bearing body 421 ).

[0167] Similar to as described previously for Figures 4A and 4B, the base 444 of each bearing body 421 has a slight convex profile providing an initial engagement surface for a contact surface of the joint about the distal outer end or an outer section of the base 444. The lowest point of the curve relative to the fastening axis X provides that initial engagement surface / point. Similarly, the engagement surface 430 at the top of each bearing body 421 also comprises a sloped curved surface which extends and is angled downwardly relative to the fastening axis X from a distal outer end to a fastening end proximate to the fastening aperture 442. In embodiments, the slope is designed to enable the engagement portion 436 of the fastening nut 418 or fastener head 414B to contact the outer perimeter of the relevant engagement surface 430 (through the washer 419A or 419B) first transferring force through the insert / washer 419A, 419B to the distal outer end 444A (outer perimeter) of the base 444 of the bearing body 421 to the contact surface 427A of the composite material about the attachment apertures 424A, 424B. As the fastening nut 418 is tightened on bolt 414, more of the flat surface of the engagement portion 436 of the fastening nut 418 and fastener head 414B contacts the top engagement surface (through the respective washer 419A, 419B), and more of the base 444 contacts the contact surface 427A about the attachment apertures 424A, 424B. Thus when the joint is tightened, the force is progressively transferred towards the relevant attachment aperture 424A, 424B. The outcome of this behaviour is that when full bolt tension is reached there is a substantially uniform distribution of pressure on the contact surface 427A around the attachment apertures 424A, 424B.

[0193]

[0168] It should be appreciated that the bearing bodies 421 of the sets of attachment elements 420A and 420B could form part of a shared plate (not illustrated), similar to that described above in relation to Figures 7 and 8. Here, each bearing body 421 can be incorporated into a common plate that can be configured to extend between and around at least two, preferably all of the attachment apertures 424A, 424B of the respective wheel halves 410A and 41 OB.

[0194]

[0169] While the illustrated embodiments relate to a carbon fibre wheel 10, 310, 410, it should be appreciated that the illustrated attachment arrangements could be adapted for use with any similar type of composite material, structure or component which is designed to be fastened to a mount and in which compression joint damage can occur.

[0195]

[0170] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

[0196]

[0171] Where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other feature, integer, step, component or group thereof.

Claims

CLAIMS:1 . An attachment arrangement configured to attach at least one section of a composite wheel to at least one other element, the composite wheel including at least one attachment aperture through which an elongate fastener element is inserted, the attachment arrangement including:(A) a fastening body which includes the elongate fastener element or is configured to be fastened onto the elongate fastener element, the fastener body having a fastener axis extending longitudinally therethrough, the fastening body having an engagement portion comprising a surface substantially perpendicularly aligned to the fastener axis; and(B) an attachment element that includes:• a bearing body which includes a base configured to face a surface of the composite wheel about the attachment aperture;• a fastening aperture through which the elongate fastener element is inserted when in use, the fastening aperture including a fastening axis that aligns with the fastener axis when the fastener is received within the fastening aperture;• an insert section which extends axially away from the base of the bearing body relative to the fastening axis about the fastening aperture, the insert section being configured to extend into the attachment aperture of the composite wheel; and• at least one engagement surface configured to operatively engage the engagement portion of the fastening body when the fastening body fastens to the at least one other element through the elongate fastener element, wherein the base of the bearing body comprises an angled or curved surface which extends upwardly relative to the fastening axis from a section radially spaced away from the insert section relative to the fastening axis to an end of the base proximate to the insert section.

2. The attachment arrangement of claim 1 , wherein the base of the bearing body comprises an angled or curved surface which extends upwardly relative to the fastening axis from a distal outer end thereof relative to the fastening axis or an outer section of the base proximate to the distal outer end, to an end of the base proximate to the insert section.

3. The attachment arrangement of claim 1 or 3, wherein the base of the bearing body comprises a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 0.1 to 5 degrees, more preferably 0.5 to 1 .5 degrees, more preferably 0.77 to 1 degrees.

4. The attachment arrangement of claim 1 , 2 or 3, wherein the base of the bearing body comprises a curved surface, preferably a convex curved surface, more preferably a convex profile providing an initial engagement surface for a contact surface of the composite wheel about said section radially spaced away from the insert section.

5. The attachment arrangement of any preceding claim, wherein the base of the bearing body has a contoured engagement face having a substantially complementary configuration to the surface of the composite wheel on which the bearing body engages.

6. The attachment arrangement of any preceding claim, wherein the engagement surface comprises an angled or curved surface which extends and is angled downwardly relative to the fastening axis from a section radially spaced away from the fastening aperture to an end of the engagement surface proximate to the fastening aperture.

7. The attachment arrangement of claim 6, wherein the engagement surface comprises an angled or curved surface which extends and is angled downwardly relative to the fastening axis from a distal outer end or an outer section of the engagement surface proximate to the distal outer end thereof, to an end of the engagement surface proximate to the fastening aperture.

8. The attachment arrangement of claim 6 or 7, wherein the engagement surface comprises a sloped surface having an average angle of from 0.1 to 10 degrees, preferably 0.1 to 5 degrees, more preferably 0.5 to 1.5 degrees, more preferably 0.77 to 1 degrees.

9. The attachment arrangement of any one of claims 6 to 8, wherein the engagement surface comprises a curved surface, preferably a convex curved surface, more preferably a convex profile providing an initial engagement surface for the engagement portion of the fastening body about said section of the engagement surface radially spaced away from the fastening aperture.

10. The attachment arrangement of any preceding claim, wherein the bearing body includes an outer profile comprising at least one of: a straight angular face, a curved face; or a pocketed face.

11. The attachment arrangement of any preceding claim, wherein the insert section includes at least one retention feature which resists withdrawal of the insert section from the attachment aperture.

12. The attachment arrangement of claim 11 , wherein the insert section includes at least one of: the insert section is shaped to have an interference fit within the attachment aperture; or a distal end configured to receive a retention element, preferably a clip.

13. The attachment arrangement of any preceding claim, wherein the base of the bearing body contacts the surface of the composite wheel about the attachment aperture through an intermediary body.

14. The attachment arrangement of any preceding claim, wherein the geometric shape of the bearing body is tailored to fit the available space in the proximate and adjacent surface on that section of the composite wheel.

15. The attachment arrangement of any preceding claim, wherein the fastening body comprises a fastening bolt which includes a fastening head including the engagement portion and the elongate fastener, the elongate fastener being configured to be connected in or through the other element.

16. The attachment arrangement of any one of claims 1 to 14, wherein the fastening body comprises a fastening nut which is assembled onto the elongate fastener element to operatively engage the engagement portion thereof with the at least one engagement surface.

17. The attachment arrangement of any preceding claim, wherein the elongate fastener element includes an external threaded surface, and the fastening body includes a complementary threaded internal bore.

18. The attachment arrangement of any preceding claim, wherein the at least one other element is selected from: a wheel mount; another section of an adjoining composite wheel, or another section of the at least one composite wheel.

19. The attachment arrangement of any preceding claim, wherein the attachment arrangement is configured to attach at least one section of a composite wheel to a mount, preferably a wheel mount.

20. The attachment arrangement of claim 19, wherein the distal end of the insert section extends into the attachment aperture of the composite wheel and is spaced apart from the wheel mount, or from or in an element located in, on, integral with, or adjacent to the wheel mount such that the distal end of the insert section does not directly engage with the wheel mount and / or said element.21 . The attachment arrangement of claim 20, wherein the insert section is configured to extend into and through the attachment aperture of the composite wheel.

22. The attachment arrangement of claim 20 or 21 , wherein the element located adjacent the wheel mount comprises at least one backing element configured to be inserted between the wheel mount and the composite wheel, the at least one backing element including at least one section of the fastening aperture.

23. The attachment arrangement of claim 22, wherein the backing element comprises a plate configured to abut a surface of the composite wheel about the attachment aperture.

24. The attachment arrangement of any one of claims 1 to 18, wherein the attachment arrangement is configured to attach at least a first section of a composite wheel to a second section of a composite wheel.

25. The attachment arrangement of claim 24, wherein the first section and the second section of the composite wheel comprise complementary halves which can be coupled together by the attachment arrangement.

26. The attachment arrangement of claim 24 or 25, wherein the attachment arrangement comprises: a fastening arrangement comprising two fastening bodies which are operatively associated with an elongate fastener element, at least one of the fastening bodies being configured to be fastened onto the elongate fastener element, each fastener body having a fastener axis extending longitudinally therethrough, each fastening body having an engagement portion comprising a surface substantially perpendicularly aligned to the fastener axis; and two attachment elements, each insert being associated with one of said two fastening bodies, each attachment element including:• a bearing body which includes a base configured to face a surface of the composite wheel about the attachment aperture;• a fastening aperture through which the elongate fastener element is inserted when in use, the fastening aperture including a fastening axis that aligns with the fastener axis when the fastener is received within the fastening aperture;• an insert section which extends axially away from the base of the bearing body relative to the fastening axis about the fastening aperture, the insert section being configured to extend into the attachment aperture of the composite wheel; and• at least one engagement surface configured to operatively engage the engagement portion of the associated fastening body when that fastening body fastens through or by the elongate fastener element,wherein the base of each bearing body comprises an angled or curved surface which extends upwardly relative to the fastening axis from a section radially spaced away from the insert section relative to the fastening axis to an end of the base proximate to the insert section.

27. The attachment arrangement of claim 24, 25 or 26, wherein the insert section is configured to terminate within the attachment aperture of the section of composite wheel in which the attachment element is located.

28. The attachment arrangement of any one of claims 24 to 27, wherein the insert section of each attachment element is configured with a distal end that is spaced away from the distal end of the opposing insert section.

29. The attachment arrangement of any preceding claim, wherein the base of the bearing body is configured with sufficient surface area sufficient area under the bearing body to reduce the compressive load on the laminate to a threshold load of less than 150 MPa, preferably less than 100 MPa.

30. The attachment arrangement of any preceding claim, wherein the composite wheel includes at least two attachment apertures, and the bearing body extends over the surface of the composite wheel between and around each of the at least two attachment apertures.31 . The attachment arrangement of claim 30, wherein the bearing body comprises a substantially planar body, preferably a plate, which extends between and around each attachment aperture.

32. The attachment arrangement of claim 30 or 31 , wherein the bearing body includes at least two fastening apertures and at least two insert sections corresponding to the number of attachment apertures in said composite wheel, each insert section extending into a respective attachment aperture of the composite wheel.

33. The attachment arrangement of any preceding claim, wherein the attachment element is configured to be received and inside a recess formed in the adjoining section of the composite wheel.

34. The attachment arrangement of any preceding claim, wherein at least a portion of the at least one engagement surface is located between the base of the bearing body and a distal end of the insert section.

35. The attachment arrangement of claim 34, wherein the at least one engagement surface includes a distal end and said distal end of the engagement surface is located axially away from the base of the bearing body relative to the fastening axis and between the base of the bearing body and the distal end of the insert section.

36. The attachment arrangement of any preceding claim, wherein the at least one engagement surface is located axially away from the base of the bearing body, and axially through and below the fastening aperture, relative to the fastening axis.

37. The attachment arrangement of any one of claims 1 to 33, wherein at least part of the least one engagement surface is located axially above the base of the bearing body relative to the fastening axis.

38. The attachment arrangement of any one of claims 1 to 33, wherein the at least one engagement surface is substantially located between the base of the bearing body and the distal end of the insert section.

39. The attachment arrangement of any preceding claim, wherein the bearing body includes a body aperture sized to receive at least a portion of the fastening body, the body aperture preferably extends into the insert section of the attachment element.

40. The attachment arrangement of any preceding claim, wherein the engagement surface comprises a substantially annular portion of an inner wall of the insert section.

41. The attachment arrangement of any preceding claim, wherein the composite wheel comprises a carbon fibre composite wheel.

42. A composite wheel including the attachment arrangement according to any preceding claim.

43. A composite wheel according to claim 42, comprising a carbon fibre composite wheel.

44. A composite wheel according to claim 43, wherein the composite wheel comprises a vehicle wheel, preferably at least one of: an automotive wheel, or an aerospace wheel.

Images