EP4724282A1

EP4724282A1 - Improved bicycle wheel

Info

Publication number: EP4724282A1
Application number: EP24732788.5A
Authority: EP
Inventors: Filippo GALLI; Davide Fumagalli
Original assignee: Colnago Ernesto E C Srl
Current assignee: Colnago Ernesto E C Srl
Priority date: 2023-06-07
Filing date: 2024-05-24
Publication date: 2026-04-15
Also published as: WO2024252220A1; IT202300011634A1

Abstract

A bicycle wheel comprises a rim (2) coupled to a tubeless or tubeless-ready tyre (3), the rim (2) having a plurality of chambers (12, 16) including a first chamber (12), open, adapted to house the edges of the tyre (3) and a second chamber (16), closed, connected to the spokes (5) of the wheel (1). There is provided for a third chamber (20) fluidically connected to the first chamber (12) so as to have air at the same pressure in both.

Description

IMPROVED BICYCLE WHEEL

Forming an object of the present invention is a bicycle wheel according to the preamble of the main claim. Such preamble relates to DE102008054214.

As known, a common bicycle wheel comprises a rim supporting a tyre. The rim has a plurality of spokes connected to a hub of the wheel.

With regard to bicycles, in particular high end bicycles, one of the main needs lies in finding a compromise between the comfort of use of the vehicle with optimal absorption of the impacts felt by the cyclist and a high grip of the tyres (tubeless or tubeless-ready) on the ground, on the one hand and having an acceptable load support and ability of the tyre to slide on the ground mentioned above. Such problems can usually be solved by reducing the inflation pressure of the tyre so as to have a greater grip and, on the contrary, by increasing such pressure so as to have an excellent load support and ability to slide.

In order to achieve such compromise, various solutions are known. One of them lies in increasing the volume of the air present in the tyre by increasing the size of the rims (increasingly wider transversely) and by using even larger tyres. All this without proportionally increasing the weight of the wheel, due to the use of increasingly lighter materials to obtain wheel components (rim and tyre).

However, if on the one hand increasing the size allows to increase comfort and grip on the ground, on the other hand such prior art solution has led to generally significantly large bicycles, created problems relating to compatibility with other components of the vehicle, and decreased the reactivity of the "bicycle system" beyond a predefined threshold.

Other solutions have focused on laterally strengthening each tyre and seeking utmost lateral stiffness of the wheel so as to able to overcome high loads and protect the rim against impacts. However, such solutions are also demanding and create high rolling resistance.

Further prior art solutions provide for active systems adapted to control the inflation pressure of the tyre. This allows to change the pressure of the latter as a function of the required grip and comfort. However, such solutions are complex and demanding; furthermore, they do not provide excellent load support when the pressure of the tyre is low.

Lastly, the bicycle wheels usually comprise one or two chambers: in the latter case, a first chamber (open) supports the edges of the tyre, while a second closed chamber is constrained to the spokes. Rims with multiple chambers, independent and separated from each other, adapted to offer greater stiffness and resulting robustness to the rim, are also known.

An object of the present invention is to provide an improved bicycle wheel with respect to the prior art solutions.

In particular, an object of the present invention is to provide a bicycle wheel which allows to obtain an excellent compromise between the needs of offering a high comfort to the cyclist, a high grip of the wheel on the ground and which at the same time allows a high ability of the wheel to slide on the ground.

Another object is to provide a wheel of the type mentioned above, which ensures a greater load support as the intensity of the stresses increases, allowing to obtain high support and ability to slide on the ground.

These and other objects which shall be more apparent to the person skilled in the art are attained by a wheel according to the attached claims. For a better understanding of the present invention, the following drawings are attached hereto, purely by way of non-limiting example, wherein: figure 1 shows a perspective view of a wheel obtained according to the present invention; figure 2 shows a front view of the wheel of figure 1; figure 3 shows a sectional view according to line 3-3 of figure 2; figure 4 shows a sectional view according to line 4-4 of figure 2; figure 5 shows an enlarged perspective view of the detail indicated with A in figure 4; figure 6 shows a sectional view according to line 6-6 of figure 5; and figures 7-9 show sectional views according to line 7-7 of figure 6, but relating to different variants of the invention.

With reference to the aforementioned figures, a bicycle wheel is generally indicated with 1. It comprises a rim 2 supporting a tubeless or tubeless-ready tyre 3; the rim is connected to spokes 5 connected to a hub 6.

The rim comprises a body 10 which is generally defined by a splining diameter DI, a width A of an internal groove thereof and by a height H.

The internal groove opens in a first chamber 12 of the rim, open and at whose sides 13 and 14 the shoulders 15 of the tyre 3 are connected.

The rim 2 has a second chamber 16 delimited at the lower part by an inner side (or "inner arc") 17 of the rim 2. Such second chamber 16 houses the heads (not shown) of the spokes 4 which allow to fix the spokes to the rim.

The rim 2 has a third chamber 20 between the first chamber 12 and the second chamber 16. Such third chamber is separated by a lower bridge (or lower partitioning septum) 21 from the second chamber 16 and by an upper bridge (or upper partitioning septum) 23 from the first chamber 12. The third chamber (just like the first and the second) is laterally delimited by two side walls 26 and 27 of the rim 2.

According to a characteristic of the invention, in the upper bridge 23 there are present one or more holes or slots 30; should there be a plurality of holes or slots 30, they are spaced apart from each other, and place the third chamber 20 in fluidic communication with the first chamber 12 and therefore with an internal volume 32 of the tyre.

Such holes and/or slots do not interrupt the contact surface between the rim 2 and the tyre 3, but they are only found in the upper bridge 23. The holes and/or slots 30 are preferably equally spaced from each other, for example by an angle (at the centre of the wheel) equal to 60° or 90°.

Due to the conformation of the rim 2, there will be air at the same pressure both in the first chamber 12 and in the third chamber 20 once the tyre has been fitted and inflated. The volume of said pressurised air is therefore greater than the one present only in the first chamber 12 (that is in the tyre) of the wheels of the prior art (with a single chamber or with two separate chambers). Such pressurised air volume may also exceed that of the wheels of the prior art by 100% depending on the sizes of the rim and tyre with respect to a similar conventional rim equipped with the same tyre.

This results in better load support, a more progressive absorption of unevenness, and greater self-repair capacity in case of puncture: as a matter of fact, as known, in modern tubeless tyre solutions with sealant fluid, the fluid therein solidifies upon contact with the external air, exiting from a damaged area (for example a puncture) and repairing it. The invention allows the greater air volume present in the third chamber 20, besides the one present in the tyre, allows for a greater action time for the sealant, before the tyre deflates entirely. In any case, the invention allows a slower deflation, therefore enhancing safety.

Clearly, the coupling between the rims of different profile and tyres will result in a different increase in air volume changing the volumes of the first and of the third chamber (that is of the tyre and of the third chamber).

Furthermore, the rim 2 is compatible with a valve 35 for inflating the tyre (reachable from the inner side or inner arc 17 of the rim 2), said valve being standard for tubeless tyres. Such valve allows to simultaneously introduce air into the chambers 12 and 20.

As shown in the figures 7-9, the valve 35 may be associated with the rim with different modes: for example, with the head 36 of the valve 35 in contact with the lower bridge 21, which contributes to a greater lightness of the rim 2 (see figure 7). In this manner, the air is introduced into the third chamber 20 and it therefore passes into the first chamber 12 and into the tyre 3 through the holes or slots 30.

Alternatively, as shown in figure 8, the head 36 of the valve may be brought into contact with the upper bridge 23 and open into the chamber 12 (and the groove defined by such bridge 23 and by its sides 13 and 14); this facilitates the fitting and the beading of the tyre 3. From the first chamber 12 the air reaches the third chamber 20.

A final alternative is shown in figure 9, where the valve is similar to that of figure 7, but it is provided with an internal extension 39 which terminates in the first chamber 12 and which allows in the beading, inflation and deflation steps the air to reach or come directly into or from the internal of the tyre, therefore facilitating these procedures.

A preferred solution of the invention has been described.

However, even other variants may be provided in the light of the description above and they fall within the scope of protection of the claims that follow that define the invention.

Claims

1. Bicycle wheel comprising a tubeless or tubeless-ready tyre (3) supported by a rim (2), the rim having spokes (4) connected to a hub (5), the rim (2) comprising a first chamber (12) directly connected to the tyre (3) and a second chamber (16) connected to said spokes (4), the rim (2) including a third chamber (20) separate from the second chamber (16), but placed in fluid communication with the first chamber (12), such first and third chamber (12, 20) containing air with the same pressure, characterised in that there is provided for a lower partitioning septum (21) between the second chamber (16) and the third chamber (20) and an upper partitioning septum (23) between said third chamber (20) and the first chamber (12), said upper partitioning septum (23) being drilled (in 30) so as to place in communication the first and the third chamber (12, 20), said first and third chamber (12, 20) containing air with the same pressure.

2. Wheel according to claim 1, characterised in that the upper partitioning septum (23) comprises a plurality of holes or slots (30) spaced apart to place in communication the first chamber (12) with the third chamber (20).

3. Wheel according to claim 2, characterised in that the holes (30) of the plurality of holes or slots (30) are equally spaced from each other.

4. Wheel according to claim 1, characterised in that provided for is a valve (35) for introducing air into the first and into the third chamber (12, 20) consequentially, said valve being reachable at an inner arc (17) of the circle (2).

5. Wheel according to claim 4, characterised in that the valve (35) opens in the third chamber (20) and it allows to direct air into this chamber and, through each hole (30), into the first chamber (12).

6. Wheel according to claim 4, characterised in that the valve (35) opens in the first chamber (12) and it allows to direct air into the third chamber (20) through each hole (30) present between such chambers (12, 20).

7. Wheel according to claim 6, characterised in that a head (36) of the valve (35) through which the air flows opens directly into the first chamber (12) or it opens in this chamber through an extension (39) provided for in the third chamber (20).