GB2180510A

GB2180510A - Vehicle wheel

Info

Publication number: GB2180510A
Application number: GB08622154A
Authority: GB
Inventors: Michel Tremaux; Jean Lacoste; Robert Schley
Original assignee: Commissariat a lEnergie Atomique CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 1985-09-18
Filing date: 1986-09-15
Publication date: 1987-04-01
Also published as: IT1195162B; IT8667709A0; FR2588510A1; GB2180510B; IT8653842V0; GB8622154D0; FR2588510B1

Abstract

A lightweight vehicle wheel comprises two disks (10a, 10b) made from titanium or titanium alloy extending between and secured to a hub (8) and rim (4). Each disc (10a, 10b) is perforated by openings (12), has a two part profile and is covered on its outer face by a tight cover (14). This leads to better running qualities. whilst avoiding the introduction of water and mud into the wheel. The wheel may be used for cycles, sulkies or invalid cars. <IMAGE>

Description

SPECIFICATION Vehicle wheel The present invention relates to an improved lightweight vehicle wheel usable more particularly for lightweight vehicles such as cycles, sulkies, invalid cars, etc.

The wheels which are at present used on vehicles of this type are equipped with spokes which connect the rim to the hub. Generally the end of the spokes fixed to the rim is threaded and bent, whilst the other end of the spoke has a head, which is fixed to the hub.

An eyelet nut maintains each spoke under tension, which thus ensures the geometry of the assembly. In the case of racing cycles, particularly those used for speed trials, such as hour records, the wheels are covered on both faces by covers, which improve the aerodynamics thereof by cancelling out air turbulence caused by the spokes. In the case of sulkies, both faces of the wheels are covered by joined plastics material disks, which protect the spokes and also provide a protective and safety function with respect to blows from shoes.

However, in both cases, this protection does not prevent spokes from breaking. It is not tight and water and mud can penetrate the wheel, which significantly increases the weight. Plastics materials wheels have recently been used on mopeds, scrambling cycles and sulkies with a view to lightening the same.

The rim is connected to the hub by polyamide and glass fibre bars. Although this leads to the weight of the wheel being reduced, it does not prevent incidents due to risks of the spokes breaking.

The object of the present invention is to eliminate these disadvantages by proposing a wheel having better running characteristics than existing wheels, it being more solid, lighter and tight with respect to water, mud and dust, no matter what the climatic or atmospheric conditions.

In per se known manner, the wheel according to the invention has a hub, a rim, two disks and means for mounting each disk on the one hand on the hub and on the other on the rim, the two disks being symmetrical with respect to a plane perpendicular to the axle of the wheel when in the fitted position.

According to the invention, the means for fitting the disks to the hub and/or rim are able to ensure a dismantlable connection, the disks being made from titanium or titanium alloy, have a profile in two conical parts and are perforated, each being covered on its outer face by a tight cover, said wheel also having means for fixing the disks in a tight manner both to the hub and to the rim.

In the wheel according to the invention, each disk may have a first conical part located in the vicinity of the hub and having a vertex angle between 150 and 1600 and preferably close to 1500 and a second conical part located between the first conical part and the rim and having a vertex angle between 170 and 1800 and preferably close to 174 .

The construction of this wheel makes it possible to obtain better running characteristics due to the mechanical strength and elasticity of the material forming the disks, so that a wheel which is lighter and more solid than existing wheels is obtained. Although titanium and alloys thereof are the preferred materials, it would not fall outside the scope of the invention to replace them by materials having the same mechanical strength and elasticity qualities. Running is also improved as a result of the profile of the disks in the form of two conical parts, which improves the aerodynamics of the wheel and eliminates water and mud. Finally, the fact that the disks are perforated and covered with a cover makes it possible to further reduce the weight of the wheel, whilst retaining its sealing sealing effect and its resistance to lateral shocks or impacts.

Preferably, the material from which the tight cover is made is chosen from among aramide fibre fabrics, such as Kevlar, whilst the rim is made from a material chosen from among aluminium alloys and the hub is made from a light alloy. The disks can be made in one piece or in the form of sectors welded edge to edge.

The means for tightly fixing each disk to a rim made in one piece may comprise tight rivets and a joint placed between the outer edge of the disk and the rim. Fixing the disk to the rim by means of rivets ensures that the joint is fixed between outer edge of the disk and the rim, whereby the joint can be placed in a groove provided on the latter.

The means for tightly fixing each disk to a rim made in two symmetrical parts with respect to a plane perpendicular to the wheel axle may comprise an embedded nut, fixing screws and a joint located between the outer edge of the disk and the rim, whereby the joint can be placed in a groove provided on the latter.

The means for tightly fixing each disk to the hub may comprise a ring mounted on the hub, a clamp and means for fixing the clamp to the ring, the clamp and the ring being shaped in such a way that they grip tightly round the disk and the cover, when they are fixed to one another. The internal conicity of the clamp aids the removal of water and mud by centrifuging.

Optionally, the space between the disks can be filled with a lightweight material, e.g. expanded polystyrene balls in order to complete the sealing device.

Finally in at least one of the disks it is possible to provide and opening giving access to an inflating valve. The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings in which: Fig 1, is a diagrammatic side view, partly broken away, of a wheel according to the invention; Fig 2, is a diagrammatic sectional half-view of a wheel according to the invention on a plane containing the wheel axle; Fig 3, is a diagrammatic, larger scale sectional view in a plane containing the wheel axle, illustrating the fitting of the disks to the hub and the fitting of the latter to the wheel axle; and Fig 4, is a sectional view illustrating a rim in two parts.

On referring to fig 1, it can be seen that the wheel according to the invention 2 comprises, in conventional manner, a rim 4 on which is a tyre 6 and hub 8. Rim 4 can be made from an aluminium alloy, such as .g. Zicral, which essentially contains 91% aluminium, 5% zinc and 2% magnesium, the remainder being constituted by copper and chromium. It can also be made from flexible composite materials, such as glass fibre-reinforced polyamide, or lightweight materials such as glass fibres or aramide fibres. It has a conventional profile, but on the inside is provided with two lips 5 (fig 2), whose usefulness will be defined hereinafter.

The hub and rim are connected to one another by means of disks 10, one on each side of the wheel. The disks are provided with openings 12, in order to make them lighter and are covered on their outer face by a cover 14 shaded grey in fig 1.

The structure of this wheel can best be gathered from the sectional view of fig 2, where it is possible to see rim 4 on which is fitted the tyre 6 and within which is located an inner tube 7. Disks 10a, 10b are fixed to wheel hub 8 by means of a rim 16 and clamp 18 and this will be described in greater detail hereinafter with reference to fig 3. Furthermore, disks 10a, 10b are fixed to the lips 5 of rim 4 by means of rivets 20. The latter must be tight and can be hollow rivets, such as those used in aviation. The disks have a raised outer edge 22 and a joint 24, which can be of natural rubber, is placed between edge 22 and rim 4, e.g. in a groove provided in the latter. The shape and dimensions of the different components are such that the fixing of disks 10 to the rim by means of rivets 20 leads to the securing of joint 24 between the rim and the outer edge 22 of the disks.

In a variant shown in fig 4, rim 4' is in two parts which are symmetrical with respect to the plane perpendicular to the wheel axle and has embedded nuts 50 and fixing screws 49 ensuring the connection and mechanical strength of the disk-rim assembly and the fixing of joint 24 in a recess. This variant is particularly adapted to the case of a solid tyre 6'.

Fig 2 also shows that each of the disks, e.g. 10b is in two parts. Thus, there is a first conical part 26 located in the vicinity of the hub and having a first vertex angle, which is followed by a second conical part 28 between the first conical part and the rim. The second conical part 28 has a vertex angle differing from that of the first conical part 26 and is preferably larger. For testing purposes, a wheel of this type was produced in which the first conical part had a vertex angle of 1500 and the second conical part a vertex angle of 174", but other values are possible without passing beyond the scope of the invention.

This arrangement makes it possible to improve the removal of water by centrifuging in the case rain or travelling on wet ground.

Disks 10a, 10b are made from a material having a good mechanical strength, as well as considerable elasticity. For this purpose, it is possible to use titanium or alloys with a high titanium content, such as e.g. alloy UTA 6 V, which contains 89% titanium, 6% aluminium, 4% vanadium, the remainder being constituted by iron, carbon, nitrogen, oxygen and hydrogen. The use of this material and the presence of openings 12 makes it possible to obtain a weight gain of approximately 25% compared with conventional wheels. Higher weight gains (approximately 30%) can be obtained with other materials having similar mechanical properties, such as e.g. Kevlar. Openings 12 make it possible to lighten the disks without leading to any loss of the mechanical qualities thereof.The perforated or unperforated disks can be produced in one piece, or in the form of several member which are fixed tightly to one another. For example, they can be produced in the form of sectors which are welded edge to edge, the planes of the joint 11 being diagrammatically illustrated by mixed lines in fig 1.

Sealing is ensured by cover 14, diagrammatically indicated in mixed line form in fig 2. It is placed on the outer face of disks 10a, 10b and is fixed to disk by any appropriate means and preferably by adhesion. On the hub side, the cover 14 is gripped between the disk and the clamp 18. On the rim side, no useful purpose is served by the cover 14 extending beyond rivets 20, because the latter are tight and joint 24 is provided. The presence of cover 14 prevents the penetration of water, mud of dust into the wheel through openings 12. Optionally, the space between the disks can be filled with a lightweight material, e.g.

expanded polystyrene balls 29, in order to complete the sealing device.

Figs 1 and 2 show that on disk 10b, in the vicinity of rim 4, is provided an opening 30 giving access to an inflating valve 32, which is sealed by a mask, which adopts the profile of the disk. For this purpose, it is necessary to cut the cover 14 at opening 30, sealing being provided by the mask 34. Obviously, when using a puncture-proof tyre, there is no inflating valve and it is possible to eliminate the opening 30.

A more detailed description will now be given of the fitting of the disks on the hub with reference to fig 3. The latter shows one of the ends of hub 8, fitting being identical at the other end of said hub. The latter is mounted on the wheel axle 36 by means of a ball bearing 38, secured by a nut 40 and protected by a joint 39. This fitting is of a conventional nature and will not be described in detail here.

Fig 3 also shows that disk 10 and cover 14 are gripped between a ring 16, mounted on the hub, and a clamp 18. The latter, which is located on the outside of the wheel, is mounted and secures on ring 16 by any appropriate means, e.g. with the aid of screws 42 which are screwed into nuts 44 welded onto ring 16. The heads of screws 42 are placed in holes 43 provided on claim 18, so as not to destroy the wheel aerodynamics.

The welded nuts 44 can be made from any suitable material, e.g. titanium. This arrangement ensures an adequate gripping of the disk 10 and the cover 14 between ring 16 and clamp 18, in order to prevent water and dust from penetrating the interior of the wheel.

Moreover, clamp 18 constitutes a protective cap for the hub as a result of its internal conicity 45, which assists the removal of water and mud by centrifuging. Finally, sealing is further improved with the aid of a baffle washer 46, which is held by screw 40 against ball bearing 38 via securing washer 48. Moreover, ring 16 and clamp 18 ensure a correct centering of the disks with respect to- the hub and absorb radial forces.

The wheel according to the invention has particularly interesting advantages, the most important of these being good sealing, whilst being lighter and provided better running characteristics than the presently used wheels.

Thus, the presence of cover 14 on the outer face of the disks, as well as the fixing of the latter to the hub and the rim, prevent air, water and dust from penetrating the wheel.

The particular configuration of the disks with two conical parts having different slopes, as illustrated in fig 2, helps to remove water and dust by centrifuging and also assists the air flow. Moreover, the great elasticity of the materials used and particularly titanium alloys makes it possible to ensure running continuity when taking bends at high speed, because the wheel can deform and return to its initial state on coming out of the bend. This prevents frequent side-slipping due to a greater rigidity of the coupling in existing wheels. Moreover, the risks of accidents due to the tearing of protection means and breaking of spokes are eliminated. There is also a reduction to the risk of accidents to horses when the wheel is mounted on a sulkie. Aerodynamics are improved, because the profile of the disks reduces the area of the maximum cross-section by more than 20% and improves the coefficient of drag compared with a conventional wheel. The disks can be dismantled and in the case of a symmetrical wheel are interchangeable. Finally, the rim produced in two symmetrical parts makes it possible by unscrewing one of these parts to rapidly change the tyre and particularly a puncture-proof tyre.

Claims

1. Lightweight vehicle wheel comprising a hub (8), a rim (4), two disks (10a, 10b) and means for fitting each disk on the one hand to hub (8) and on the other to rim (4), the two disks (10a, 10b) being symmetrical with respect to a plane perpendicular to the wheel axles when in the fitted position, characterized in that the means for fitting the disks (10a, 10b) on hub (8) and/or rim (4) are constructed so as to ensure a dismantlable connection, the disks (10a, 10b) being made from titanium or titanium alloy, have a profile in two conical parts (26, 28) and are perforated and covered on the external face of each of them by a tight cover (14), said wheel also having means for fixing the disks tightly (10a, 10b) to hub (8) and rim (4).

2. Light vehicle wheel according to claim 1, characterized in that each disk (10b) comprises a first conical part (26) in the vicinity of the hub and having a vertex angle between 150 and 160 and preferably close to 150 and a second conical part (28) located between the first conical part (26) and the rim (4) and having a vertex angle between 170 and 180 and preferably close to 174 .

3. Lightweight vehicle wheel according to either of the claims 1 and 2, wherein the material from which the tight cover (14) is made is chosen from aramide fibre fabrics.

4. Lightweight vehicle wheel according to any one of the claims 1 to 3, characterized in that at least one of the disks is made in one piece.

5. Lightweight vehicle wheel according to any one of the claims 1 to 4, characterized in that at least one of the disks is made in the form of sectors welded edge to edge.

6. Lightweight vehicle wheel according to any one of the claims 1 to 5, characterized in that the means for tightly fixing each disk (10) to the rim (4) comprise tight rivets (20) and a joint (24) placed between the outer edge (22) of disk (10) and rim (4).

7. Lightweight vehicle wheel according to any one of the claims 1 to 6, characterized in that the rim (4') is made in two parts symmetrical with respect to a plane perpendicular to the wheel axle, the means for tightly fixing each disk (10) to the rim (4") comprising an embedded nut (50), fixing screws (49) and a joint (24) located between the outer edge (22) of disk (10) and rim (4").

8. Lightweight vehicle wheel according to any one of the claims 1 to 7, characterized in that the means for tightly fixing each disk (10) to hub (8) comprise a ring (16) mounted on hub (8), a clamp (18) and means for fixing the clamp (18) to ring (16), clamp (18) and ring (16) being shaped in such a way that they tightly grip round disk (10) and cover (14) when fixed to one another, clamp (18) having a hub protecting function because, as a result of its internal conicity (45), it makes it possible to remove water and mud centrifuging.

9. Lightweight vehicle wheel according to any one of the claims 1 to 8, characterized in that the space between the disks is filled with a lightweight material.

10. Lightweight vehicle wheel according to any one of the claims 1 to 9, characterized in that the lightweight material is constituted by expanded polystyrene balls.

11. Lightweight vehicle wheel according to any one of the claims 1 to 10, characterized in that at least one of the disks has an opening (30) giving access to an inflating valve (32) and which is closed by a mask, which adopts the profile of the disk.

12. Lightweight vehicle wheel substantially as hereinbefore described with reference to, and as shown in, Figure 1,2 and 3, or Figure 4, of the accompanying drawings.