TW202428488A - Aerodynamic profile - Google Patents

Abstract

Aerodynamic symmetrical profiled element (1) for a wheeled vehicle (V) having, in cross section perpendicular to the plane of symmetry (12), at least 90% of the central part of a sage leaf profile with at least 5 arcs of circle, with a ratio between maximum spacing (E) measured perpendicular to the plane of symmetry (12) and cord (C) measured in the plane of symmetry (12) comprised between 0.1 and 0.3. Said profiled element is adapted to create a force always directed towards the leading edge (16) of the profiled element for all the resultants combining the speed of the wind and the forward speed of the vehicle.

Description

Air powered appearance

The subject of the invention is an aerodynamically symmetrical profile element for a slow-moving vehicle moving at a speed of less than 100 km/h, such as a bicycle, advantageously a bicycle with electric assistance.

By slow-moving vehicle we advantageously refer to bicycles, electric bicycles, mopeds, electric assist scooters, and the like.

Many bicycle manufacturers are interested in finding solutions that improve rider performance. As a result, some have looked for ways to reduce the weight of bicycle frames as much as possible, sometimes to the point of compromising the strength of the bicycle.

Other manufacturers have been interested in improving the aerodynamics of their bikes, especially those working on "rider and bike". These manufacturers have done extensive testing in aerodynamic tunnels, trying to find the best aerodynamic characteristics, especially in headwind conditions.

As examples of research conducted to improve bicycle aerodynamics, see the following: - Timothy N. Crouch et al., “Riding against the wind: A review of competitive bicycle aerodynamics”, Sports Engineering (2017) 20:81-110, (the article concludes that future research is needed to improve cyclist performance—improving cyclist performance is still relevant in 2017), - Malizia Fabio et al., “Bicycle aerodynamics: history, state of the art, and future prospects”, Journal of Wind Engineering and Industrial Aerodynamics 200, 2020 (this study also concludes that the complexity of bicycle aerodynamics presents many difficulties and leaves room for research and innovation to improve aerodynamics.); - Schwabb A. et al., “Some effects of crosswinds on bicycle lateral dynamics”, ISEA Conference Proceedings 2018, 2, 218 (this study analyzes the effects of crosswinds on rider stability).

All of this research shows that despite many improvements that have been made to bicycles, those in the field are still looking for innovations in bicycle aerodynamics that can improve rider performance.

Research has also been conducted to minimize the drag effect of bicycles (see for example Belgian patent BE 2008/0357 and its US equivalent US2009/0322053 or US application US2010/0253038). US patent US8556208 describes a bicycle frame profile in the shape of an airplane wing. US patent US7322592 describes an aerodynamic cover for a bicycle. International patent application WO2014/191417 describes a complete bicycle fairing.

The applicant is also aware of a range of frames sold under various brands or trade names, namely, Pinarello, Bianchi, Cervelo, Scott, BMC, Jamis, Trek, Ridley Bikes, Giant, Eddy Merckx, Gazelle, Peugeot and Mercedes.

None of the frames described and/or sold in these documents have a sage leaf shaped cross-section with 5 tangent radii.

After research and extensive testing, the applicant discovered that by using a very special profile in the shape of a sage leaf with 5 tangent arcs or circle segments, it is possible to reduce or even completely eliminate the drag, but in addition to this, to generate a positive force in the direction of the bicycle's forward motion in the case of a side or oblique wind, even in the case of a headwind. This effect is very surprising and has not been described or suggested in the prior art.

The applicant thus noted, after a series of tests, that by using a bicycle frame with a specific sage leaf profile, it is possible to generate a motor effect of about 5N to 10N or even more due to the specific profile of the wind on the frame relative to the direction of travel or movement of the bicycle at wind speeds of 10km/h to 50km/h and angles of incidence of 10° to 25°, and then generate a power contribution of 30W to 60W depending on the forward speed of the bicycle and the wind speed and its angle of incidence. This beneficial effect cannot be obtained using commercial bicycle frames. Even more surprising is that the applicant noted during tests with wind speeds between 10 and 50 km/h that the motor effect was always obtained for any angle of incidence of the wind, that is to say at times of sidewind, crosswind, downwind and headwind, even at low wind angles relative to the direction of travel or motion of the vehicle. The special sage leaf shape was also shown to reduce friction losses in all winds, including wind speeds between 10 and 80 km/h.

Tests conducted by the applicant have shown that when deviating from the sage leaf profile, crosswinds no longer have any appreciable motion effect, such as headwinds with a lead angle of 15° or less.

The motor effect achieved by the invention is particularly significant for electric assist bicycles, since it saves watt-hours (Wh) of the battery, thereby allowing a reduction in the size of the assist battery used to move over a given distance, reducing the overall weight of the bicycle with the battery, or providing electric assistance for longer distances for the bicycle. Reducing the size of the battery also allows it to be better integrated into the frame of the bicycle or its compartment, thereby better protecting it from inclement weather and theft or other acts of vandalism.

The invention therefore relates to an aerodynamically symmetrical profile element (1) for a wheeled vehicle (V) having, in a section perpendicular to a symmetry plane (12), at least 90% of the central portion of the profile having at least 5 arcs, called sage leaves, with a ratio between the maximum spacing (E) measured perpendicular to the symmetry plane (12) and the chord (C) measured in the symmetry plane (12) of between 0.1 and 0.3. The profile is suitable for generating a force always directed towards the leading edge of the profile for the combined total force of the wind speed and the forward speed of the vehicle, thereby promoting the forward movement of the vehicle.

The subject of the invention is therefore an aerodynamically symmetrical profile element for a wheeled vehicle (V), suitable for movement at a speed of less than 100 km/h at least on a surface defining a horizontal rolling plane, in particular for a bicycle, the profile element (1, 2, 3, 4) having a symmetry plane (12) and a curved front end (10) having at least one leading edge, wherein in a position of the profile element with the symmetry plane (12) lying in a vertical plane, the profile element (1, 2, 3, 4) has a curved front end (10), a rear end (11) and curved outer surfaces (13, 14) on either side of the vertical symmetry plane (12), the curved outer surfaces (13, 14) defining a horizontal rolling plane. An aerodynamic profile (15) in a cross section in a plane perpendicular to the symmetry plane (12) and parallel to the horizontal rolling plane, characterized in that, at least for a portion of the profile element (1, 2, 3, 4), the profile element has an aerodynamic profile (15) having at least 90% of the central part of a sage leaf profile in a cross section perpendicular to the symmetry plane (12) and parallel to the rolling plane (H), the aerodynamic profile (15) having a ratio between the maximum spacing (E) measured perpendicular to the symmetry plane (12) and the maximum chord (C) measured in the symmetry plane (12), which ratio is between 0.1 and 0.3, advantageously between 0.1 and 0.25.

According to the invention, the profile element is characterized in that: * the aerodynamic profile (15) having a [maximum spacing (E)/maximum chord (C)] ratio between 0.1 and 0.3, advantageously between 0.1 and 0.2, comprises two symmetrical curved shapes or surfaces (13, 14) relative to the substantially perpendicular symmetry plane (12), each of the two symmetrical curved shapes or surfaces (13, 14) being formed in a section between a first front point (16) and a second rear point (17), the first front point and the second rear point (16, 17) extending along a symmetry axis (AX) of the symmetry plane (12) parallel to the rolling plane (H), * Each of the two symmetrical curved shapes or surfaces (13, 14) of the aerodynamic profile (15) is substantially defined in cross section by 5 to 10 consecutive circular arcs, advantageously by 5 or 6 or 7 consecutive circular arcs, preferably by 5 consecutive circular arcs (A1 of circle C1, A2 of circle C2, A3 of circle C3, A4 of circle C4, A5 of circle C5), wherein the consecutive circular arcs (A1, A2, A3, A4, A5) are inscribed in pairs and have increasing curvature radii (R1, R2, R3, R4, R5), the curvature radii (R1, R2, R3, R4, R5) have a minimum curvature radius (R1) of the curved portion near the first front point (16) and a maximum curvature radius (R5) of the curved portion near the second rear point (17), the arc (A1) passing through the front end of the curve of the first front point (16) is defined by a first curvature radius (R1) contained between a center of curvature (CC1) of the symmetry axis (AX) along the symmetry plane (12) and 0.2 and 0.3 times the maximum spacing (E) * For at least a portion of the profile element (1, 2, 3, 4), at least 95% of the cross section is a cross section defined by five consecutive arcs, wherein, relative to the radius of curvature (R1) of the first arc (A1), the second arc (A2) has a radius of curvature (R2) included between 1.8 and 2.2 times the first radius of curvature (R1); the third arc (A3) has a radius of curvature (R3) included between 8.5 and 10.5 times the first radius of curvature (R1); the fourth arc (A4) has a radius of curvature (R4) included between 25 and 30 times the first radius of curvature (R1); and The fifth arc (A5) has a radius of curvature (R5) comprised between 50 and 70 times the first radius of curvature (R1).

According to an advantageous embodiment, the external shape element according to the present invention has one or more of the following features: * The circles defining the five arcs are inscribed in pairs, the first circle (C1) defining the first arc (A1) is inscribed in the second circle (C2), the second circle (C2) defining the second arc (A2) is inscribed in the third circle (C3), the third circle (C3) defining the third arc (A3) is inscribed in the fourth circle (C4), and the fourth circle (C4) defining the fourth arc (A4) is inscribed in the fifth circle (C5) defining the fifth arc (A5), and the inscribed circles define a series of different tangent points (T1, T2, T3, T4). * In a section perpendicular to the plane of symmetry (12) for at least part of the profile element (1, 2, 3, 4), the aerodynamic profile (15) has at least 95% of the central part of the sage leaf profile, with a ratio of [maximum spacing (E) measured perpendicular to the perpendicular plane of symmetry (12)/maximum chord (C) measured in the perpendicular plane of symmetry (12)] between 0.2 and 0.25. * The profile element (1, 2, 3, 4) is at least partially hollow. * With respect to the vertical plane of symmetry (12) for the vehicle (V) with its wheels resting on the horizontal rolling plane (H), the profile element (1, 2, 3, 4) has at least: * A first portion of the profile element (3), between, on the one hand, a lower cutting plane (P1) of the profile element (3) and, on the other hand, a first intermediate cutting plane (P2) of the profile element (3), the lower cutting plane (P1) being parallel to the horizontal rolling plane (H), the first intermediate cutting plane (P2) of the profile element (3) being parallel to the lower cutting plane (P1), and * the second part of the profile element (3), between, on the one hand, the first intermediate cutting plane (P2) or a possible second intermediate cutting plane parallel to the lower cutting plane (P1) but different from the first intermediate cutting plane (P2) and, on the other hand, an upper cutting plane (P3) of the profile element (3), the upper cutting plane (P3) being parallel to the lower cutting plane (P1), wherein the first intermediate plane (P2) extends between the lower cutting plane (P1) and the upper cutting plane (P3), and the optional second intermediate cutting plane extends between the first intermediate cutting plane (P2) and the upper cutting plane (P3); wherein, for each cutting plane parallel to the lower cutting plane (P1) between the lower cutting plane (P1) and the first intermediate cutting plane (P2), the first portion of the profile element (3) has, on the one hand, a substantially constant sage leaf profile with a chord (C) measured in the vertical plane of symmetry (12), and, on the other hand, a substantially constant ratio between the maximum chord (C) measured in the vertical plane of symmetry (12) and the maximum spacing (E) measured perpendicular to the vertical plane of symmetry (12), the maximum spacing (E) measured perpendicular to the vertical plane of symmetry (12), the ratio being between 0.1 and 0.3, advantageously between 0.1 and 0.25, preferably between 0.2 and 0.25.

Preferably, the second portion of the profile element (3) has, for each cutting plane parallel to the lower cutting plane (P1) between the first intermediate cutting plane or the second intermediate cutting plane and the upper cutting plane (P3): * a continuously varying sage leaf profile between - a maximum sage leaf profile along the first intermediate cutting plane or the second intermediate cutting plane (P2) having a maximum chord (C) measured in the vertical symmetry plane (12) and a maximum spacing (E) measured perpendicular to the vertical symmetry plane (12), and - a minimum sage leaf profile along the upper cutting plane (P3) having a minimum chord (C') measured in the vertical symmetry plane (12) less than the maximum chord (C) and a minimum spacing (E') less than the maximum spacing (E), Each sage leaf section has a ratio between the spacing (E, E') measured perpendicular to the symmetry plane/the chord (C, C') measured in the symmetry plane (12) between 0.1 and 0.3, advantageously between 0.1 and 0.25, preferably between 0.2 and 0.25. *When the vehicle (V) is in an upright position and the wheels rest on a horizontal plane (H), the profile element has: - a vertical plane of symmetry (12) and - at least one portion extending between a first horizontal plane perpendicular to the vertical plane of symmetry (12) and a second horizontal plane perpendicular to the vertical plane of symmetry (12), the portion being characterized by a substantially constant horizontal section substantially similar to that of a sage leaf, the substantially constant horizontal section being defined by having substantially the same length of the chord (C) measured in the vertical plane of symmetry (12) and substantially the same spacing (E) measured perpendicular to the vertical plane (12). * A combination of two or more of these features.

The invention also relates to a frame (20) of a bicycle (V) suitable for supporting at least one front wheel (21) and one rear wheel (22), the frame (20) comprising at least: (a) a saddle profile (23) having a lower end (23A) and an upper end (23B) suitable for supporting a saddle post (24), (b) a control profile (25) suitable for receiving a control lever (26), the control lever (26) being associated with at least a fork (27) and a handlebar (28) for the front wheel (21), (c) a diagonal profile (1) connecting the lower end (23A) of the saddle profile (23) to the control profile (25), and advantageously (d) connecting the upper end (23B) of the saddle profile (23) to the substantially horizontal profile (2) of the steering profile (25), The frame (20) is advantageously associated with at least a seat stay (31) and a chain stay (29) suitable for supporting the rear wheel (22), and/or with a fork (27) for the front wheel (21), and/or a front fender (30) suitable for at least partially covering the upper part of the front wheel (21), and/or a rear fender (3) suitable for at least partially covering the upper part of the rear wheel (22) and/or to a cap (4), The basic feature of the frame is that at least one element selected from the saddle profile (23), the steering profile (25), the diagonal profile (1), the optional substantially horizontal profile (2), the possible front fender (30), the possible rear fender (3) and the possible cap (4), possible combinations thereof, is an aerodynamically symmetrical profile element according to the present invention as described above.

Advantageously, the frame comprises at least one horizontal profile, a diagonal profile and a rear fender, each of which is an aerodynamically symmetrical profile element according to the invention.

According to another particular embodiment, the diagonal profile (1), the saddle profile (23) and optionally the horizontal profile (2) are integrated in the same profile element according to the invention.

Another subject of the invention is a bicycle comprising a frame according to the invention and/or associated with an exterior element in the form of a cover or partial cover according to the invention.

According to a specific embodiment of the bicycle according to the present invention, when it is in an upright position with the wheel placed on a horizontal plane (H), the aerodynamically symmetrical shape element (3) of at least one element selected from the saddle shape (23), the steering shape (25), the diagonal shape (1), the optional substantially horizontal shape (2), the optional front fender (30), the optional rear fender (3) and the optional cap (4), optionally in combination with each other, has at least one portion, which has a sage leaf cross-section in a horizontal section as defined above for the shape according to the present invention.

Another object of the invention is the use of a wheeled vehicle suitable for moving on land at a speed of less than 100 km/h in a horizontal plane, the vehicle comprising at least one profile element according to the invention, in particular at least one frame according to the invention, for generating, by the effect of the wind on the at least one profile element, at least one motor force between 2N and 10N in the direction of travel of the vehicle for wind speeds of at least between 10 km/h and 80 km/h with an angle of attack or angle of incidence relative to the direction of travel of the vehicle of at least between 10° and 170°.

In particular, the use according to the invention is for generating, by the effect of the wind on the at least one profile element, in the direction of travel of the vehicle at least one motor force between 2N and 10N for a wind speed of at least between 10 km/h and 80 km/h with an angle of incidence of at least between 10° and 170° relative to the direction of travel of the vehicle.

Advantageously, the drive force generated produces a drive power that is the product of the drive force and the rider's forward speed.

The invention thus makes it possible to use the wind to generate propulsion for the vehicle, whether it comes from the front, orthogonal to the displacement, or from the rear relative to the forward speed of the vehicle, with a wind speed of, for example, 10 to 60 km/h. This makes it possible to reduce the power required by the rider and/or the auxiliary motor of the bicycle by about 10% to 40%, thereby allowing the rider to reduce fatigue and allowing the battery to have a longer duration of action. Thus, if the rider is travelling at a speed of about 30 km/h, with a headwind or front wind of 20 to 50 km/h, with an angle of incidence of 15 to 45° relative to the direction of travel, and the power of a conventional bicycle is about 200 W, the power required by the same rider using a bicycle with a frame according to the invention is reduced by 10% to 35%.

Features and details of the present invention will become apparent from the following description with reference to the drawings.

Figure 1 shows a bicycle (V) having a frame (20) suitable for supporting at least one front wheel (21) and one rear wheel (22), the frame (20) comprising at least: (a) a saddle profile (23) having a lower end (23A) and an upper end (23B) of a saddle post (24) suitable for supporting a saddle (24A), (b) a control profile (25) suitable for receiving a control lever (26), the control lever (26) being associated with at least a fork (27) and a handlebar (28) for the front wheel (21), (c) a diagonal profile (1) connecting the lower end (23A) of the saddle profile (23) to the steering profile (25), (for this diagonal profile, the tubes of a conventional frame are shown in dotted lines.), (d) a substantially horizontal profile (2) connecting the upper end (23B) of the saddle profile (23) to the steering profile (25) (horizontal when the wheels of the bicycle are held vertically or upright on a horizontal plane H), (for this substantially horizontal profile, the tubes of a conventional frame have been shown in dotted lines.), (e) at least one seat stay (31) and one chain stay (29) suitable for supporting the rear wheel (22), (f) a fork (27) for the front wheel (21), (g) a front fender (30) adapted to at least partially cover the upper portion of the front wheel (21), and (h) a rear fender (3) adapted to at least partially cover the upper portion of the rear wheel (22).

Bicycles traditionally include a drive system, such as having a chain, pedals, gears, a sprocket unit, and advantageously an electric motor to assist the rider in moving or displacing.

In this bicycle, shown by way of example only as a vehicle intended to move in a horizontal plane at a speed of less than 100 km/h, for example, travelling in a horizontal plane H at a maximum speed of 30 to 40 km/h with a headwind (VF in FIG. 2 or 3 ) at an angle of incidence (β relative to the plane of symmetry 12 ) of 5 to 175° (for example, as specific examples: 5°, 15°, 30°, 45°, 60°, 90°, 120°, 135°, 150°, 165° and 175°) (thus allowing a displacement assist capable of reducing the rider's muscle effort by 5% to 30%), the front fender (30), the rear fender (3), the substantially horizontal profile (2) and the diagonal profile (1) advantageously have a specific aerodynamic profile in the style of a sage leaf.

The sage leaf shape of these elements has, in a section perpendicular to the symmetry plane 12, a ratio [maximum spacing (E) measured perpendicular to the symmetry plane (12)/maximum chord (C) measured in the symmetry plane (12)] between 0.1 and 0.3, advantageously between 0.1 and 0.2.

The sage leaf shape (15) of these elements (1, 2, 3, 30) comprises two symmetrical curved shapes (13, 14) (forming a hollow space between them) relative to the substantially perpendicular symmetry plane 12, each curved shape (13, 14) being formed between a first front point (16) and a second rear point (17), the first front point (16) and the second rear point (17) extending in the symmetry plane (12) and being substantially formed by tangent and increasing radii of curvature (R1, R2, R3, R4, R5) The invention is defined by five consecutive arcs (A1, A2, A3, A4, A5) having a minimum radius of curvature for the curved portion near a first front point or front end (16) and a maximum radius of curvature (R5) for the curved portion near a second rear point or rear end (17), the arc (A1) having a front end passing through the first front point (16) having a curvature center (CC1) located in the symmetry plane (12) and having a first radius of curvature (R1) contained between 0.2 and 0.3 times the maximum spacing (E). (See FIG. 10) The centers of the various curvature arcs are not on the same straight line.

Regarding the radius of curvature (R1) of the first arc (A1), the second arc (A2) has a radius of curvature (R2) between 1.8 and 2.2 times the first radius of curvature (R1); the third arc (A3) has a radius of curvature (R3) between 8.5 and 10.5 times the first radius of curvature (R1); the fourth arc (A4) has a radius of curvature (R4) between 25 and 30 times the first radius of curvature (R1); the fifth arc (A5) has a radius of curvature (R5) between 50 and 70 times the first radius of curvature (R1).

The circles (C1, C2, C3, C4, C5) defining the five arcs are inscribed in pairs, the first circle (C1) defining the first arc (A1) is inscribed in the second circle (C2), the second circle (C2) defining the second arc (A2) is inscribed in the third circle (C3), the third circle (C3) defining the third arc (A3) is inscribed in the fourth circle (C4), and the fourth circle (C4) defining the fourth arc (A4) is inscribed in the fifth circle (C5) defining the fifth arc (A5), and the inscribed circles define a series of different tangent points (T1, T2, T3, T4). Circle C3, circle C4 and circle C5 are only partially shown.

Profiles 1 and 2 each have a vertical plane of symmetry (12) for a bicycle (V) in an upright position with its wheels resting on a horizontal plane (H). The vertical plane of symmetry (12) advantageously corresponds to the vertical plane of symmetry of the rear wheel (22) of the bicycle (V). Each horizontal cutting plane (perpendicular to the vertical plane of symmetry (12) with the bicycle V in an upright or straight position with its wheels resting on a horizontal plane (H)) of the profile elements (1 and 2) defines a section with a central axis (AX) that is horizontal. Over substantially the entire (vertical) height of each profile element (1 and 2), the section in the horizontal cutting plane remains substantially constant for the bicycle V in an upright position with its wheels resting on a horizontal plane.

For the profile element (3) shown in the vertical section in FIG. 6 (section along the line VI-VI in FIG. 1 ) and in the horizontal section in FIG. 5 (for a bicycle in an upright position with the wheels resting on a horizontal plane (H)), the profile element (3) has a vertical plane of symmetry (12). For the first portion of the profile element (3) extending between the lower plane (P1) and the median plane (P2) (the planes (P1) and (P2) being horizontal and perpendicular to the vertical plane of symmetry (12) for a bicycle in an upright position with the wheels resting on a horizontal plane (H)), it has faces (13 and 14) symmetrical with respect to the vertical plane (12). For this first portion, it has a horizontal section of a sage leaf constant between the lower plane (P1) and the median plane (P2) (defined by the lines 13 and 14 in FIG. 5 ). The sage leaf horizontal section has a chord (C) and a spacing (E). For a second portion of the profile (3) extending between the intermediate horizontal plane (P2) and the upper horizontal plane (P3) of the bicycle (V), the second portion is defined by a surface (13A) and a surface (14A) when the bicycle (V) is in a standing or upright position with the wheels resting on the horizontal plane (H). Along the horizontal cutting plane, the sage leaf section of the second portion is between a maximum sage leaf section having a maximum chord (C) and a maximum spacing (E) (corresponding to the section in the intermediate plane (P2)) and a minimum sage leaf section having a chord (C') less than the maximum chord (C) and a spacing (E') reduced from the maximum spacing (E) (corresponding to the sage leaf section in the upper plane (P3)). For the second part of the profile element (3), the chord varies continuously between a maximum chord (E) and a minimum chord (E'). The profile element (3) is covered at the level of the upper plane (P3) by a cap (300) connecting the faces (13A and 14A) of the second part. (See Figures 5 and 6)

The profile elements (1, 2, 3 and 30) can be in the form of two separate parts that can be clamped together. For example, the profile elements (1 and 2) are used to be two parts that are clamped together when closing the tubes of a traditional frame of a bicycle.

According to the present invention, the tube 23, the tube 1 and the tube 2 (the parts of the reference numerals 1 and 2 indicated by dashed lines in FIG. 1 ) can be combined into a single aerodynamic profile element (3). The space 1223 defined between the reference numerals 1, 2 and 23 can then be closed by the profile element according to the present invention.

FIG7 is a schematic diagram of a cap or cover (4) which can be mounted on a bicycle by fasteners not shown on the frame of the bicycle or on the front and/or rear tray of a cargo bicycle (with or without a seat). The cap (4) forms an internal chamber forming a shelter space for the rider and/or forming a housing for equipment to be transported, equipment for maintaining the bicycle or for one or more batteries when the bicycle is equipped with electric assistance. The cap (4) has a vertical plane of symmetry (12), a horizontal central axis (AX) for the bicycle (V) in an upright position with the wheels resting on a horizontal surface. In the section between the lower horizontal plane and the mid-horizontal plane (P1 and P2), the horizontal section has an E/C ratio of 0.18 (E is the pitch and C is the chord), with the cross-sectional shape of each surface (13, 14) being tangent to each other and having a radius of curvature (R1, R2, R3) increasing with a minimum radius of curvature (R1) for the curved portion near the front end or leading edge (16) and a maximum radius of curvature (R5) for the curved portion near the rear end or tail (17). A constant sage leaf cross section defined by five continuous arcs (arc A1 of circle C1, arc A2 of circle C2, arc A3 of circle C3, arc A4 of circle C4, arc A5 of circle C5) of the embodiment of the present invention, wherein the arc (A1) at the front end of the first front point (16) defines a first curvature radius (R1) having a center of curvature (CC1) located in the symmetry plane (12) and having a maximum spacing (E) of 0.2 to 0.3 times. (See Figure 10) The centers of arcs of different curvatures (CC2 for arc A2 extending between points T1 and T2, CC3 for arc A3 extending between points T2 and T3, CC4 for arc A4 extending between points T3 and T4, and CC5 for arc A5 extending between points T4 and 17) are not aligned along the same straight line. (See Figure 10)

Between the median plane (P2) and the upper plane (P3), the profile of the section is that of a sage leaf of the type shown in Figure 10, but with a decreasing chord C' and spacing E', closer to the upper plane (P3).

The faces (13, 14) of the external elements (1, 2, 3, 30) may also be associated with photovoltaic cells for recharging one or more batteries, in particular for use in bicycles with electric motor assistance.

1: diagonal shape, shape element, tube 2: substantially horizontal shape, shape element, tube 3: rear fender, shape element 4: cap or cover 12: symmetrical plane 13: curved shape 13A: face 14: curved shape 14A: face 15: sage leaf shape 16: first front point or front end 17: second rear point or rear end 20: frame 21: front wheel 22: rear wheel 23: saddle shape, tube 23A: lower end 23B: upper end 24: saddle post 24A: saddle 25: control shape 26: control lever 27: fork 28: handlebar 29: chain stay 30: front fender, exterior components 31: rear seat stay 300: cap 1223: space A1: arc A2: arc A3: arc A4: arc A5: arc AX: center axis C: chord C': chord CC1: center of curvature CC2: center of curvature CC3: center of curvature CC4: center of curvature CC5: center of curvature E: distance E': distance H: horizontal plane P1: lower plane P2: middle plane P3: upper plane R1: radius of curvature R2: radius of curvature R3: radius of curvature R4: radius of curvature R5: radius of curvature T1: tangent point T2: tangent point T3: tangent point T4: tangent point V: bicycle

In these drawings, - [Fig. 1] is a side view of a bicycle according to the present invention, - [Fig. 2] is a cross-sectional view along the line II-II of the diagonal section of the frame of the bicycle of Fig. 1, - [Fig. 3] is a cross-sectional view along the line III-III of the horizontal section of the frame of the bicycle of Fig. 1, - [Fig. 4A], [Fig. 4B] and [Fig. 4C] are cross-sectional views along the line IVA, line IVB and line IVC of the horizontal section of the frame of the bicycle of Fig. 1, respectively (see also Fig. 3 for the cross-sectional lines IVA, IVB and IVC), - [Fig. 5] is a cross-sectional view along the line V-V of the rear fender of the frame of the bicycle of Fig. 1, - [Fig. 6] is a cross-sectional view along the line VI-VI of the rear fender of the frame of the bicycle of Fig. 1, - [Figure 7] is a side view of a bicycle hood or fairing, - [Figure 8] and [Figure 9] are cross-sectional views along line VIII-VIII and line IX-IX of the hood or fairing of Figure 7, and - [Figure 10] is a shape of an inscribed arc of a face of the sage leaf shape of the present invention.

12: Symmetrical plane

13: Curved shape

14: Curved shape

16: First front point or front end

17: Second back point or back end

A1: Arc

A2: Arc

A3: Arc

A4: Arc

A5: Arc

C: Chord

C1~C5: Circle

CC1: Center of curvature

CC2: Center of curvature

CC3: Center of curvature

CC4: Center of curvature

CC5: Center of curvature

E: Spacing

R1: Radius of curvature

R2: Radius of curvature

R3: Radius of curvature

R4: Radius of curvature

R5: Radius of curvature

T1: Tangent point

T2: Tangent point

T3: Tangent point

T4: Tangent point

Claims (11)

An aerodynamically symmetrical profile element for a wheeled vehicle (V) suitable for moving at a speed of less than 100 km/h at least on a surface defining a horizontal rolling plane, the aerodynamically symmetrical profile element being in particular for a bicycle, the profile element (1, 2, 3, 4) having a symmetry plane (12) and a curved front end (10) having at least one leading edge, wherein in a position of the profile element with the symmetry plane (12) being located in a vertical plane, the profile element (1, 2, 3, 4) has the curved front end (10), a rear end (11) and curved outer surfaces (13, 14) on either side of the vertical symmetry plane (12), the curved outer surfaces (13, 14) defining a vertical rolling plane. an aerodynamic profile (15) in a section in a plane perpendicular to the plane of symmetry (12) and parallel to the horizontal rolling plane (H), the aerodynamic profile (15) being characterized in that, at least for a portion of the profile element (1, 2, 3, 4), the profile element has an aerodynamic profile (15) having at least 90% of the central portion of the profile having the profile of a sage leaf in a section perpendicular to the plane of symmetry (12) and parallel to the horizontal rolling plane (H), the aerodynamic profile (15) having a ratio between the maximum spacing (E) measured perpendicular to the plane of symmetry (12) and the maximum chord (C) measured in the plane of symmetry (12), the ratio being between 0.1 and 0.3, advantageously between 0.1 and 0.25, wherein the aerodynamic profile (15) having a [maximum spacing (E)/maximum chord (C)] ratio between 0.1 and 0.3, advantageously between 0.1 and 0.25, comprises two symmetrical curved shapes or surfaces (13, 14) relative to the substantially vertical symmetry plane (12), each of the two symmetrical curved shapes or surfaces (13, 14) being formed in a section between a first front point (16) and a second rear point (17), the first front point and the second rear point (16, 17) extending along a symmetry axis (AX) of the vertical symmetry plane (12) parallel to the horizontal rolling plane (H), The invention is characterized in that each of the two symmetrical curved shapes or surfaces (13, 14) of the aerodynamic shape is substantially defined by 5 to 10 continuous arcs in cross section, advantageously defined by 5 or 6 or 7 continuous arcs, preferably defined by 5 continuous arcs (A1 of circle C1, A2 of circle C2, A3 of circle C3, A4 of circle C4, A5 of circle C5), wherein the continuous arcs (A1, A2, A3, A4, A5) are inscribed in pairs and have increasing curvature radii (R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, R45, R56, R57, R58, R69, R70, R71, R72, R73, R74, R75, R86, R99, R9 5), the curvature radii (R1, R2, R3, R4, R5) have a minimum curvature radius (R1) of the curved portion near the first front point (16) and a maximum curvature radius (R5) of the curved portion near the second rear point (17), the arc (A1) passing through the front end of the curve of the first front point (16) is defined by a first curvature radius (R1) contained between a center of curvature (CC1) located along the symmetry axis (AX) perpendicular to the symmetry plane (12) and 0.2 and 0.3 times the maximum spacing (E), The invention is characterized in that at least 95% of the cross section of at least a portion of the external element (1, 2, 3, 4) is a cross section defined by five consecutive arcs, wherein, relative to the radius of curvature (R1) of the first arc (A1), the second arc (A2) has a radius of curvature (R2) between 1.8 and 2.2 times the first radius of curvature (R1); the third arc (A3) has a radius of curvature (R3) between 8.5 and 10.5 times the first radius of curvature (R1); the fourth arc (A4) has a radius of curvature (R4) between 25 and 30 times the first radius of curvature (R1); and The fifth arc (A5) has a radius of curvature (R5) comprised between 50 and 70 times the first radius of curvature (R1). An aerodynamically symmetric shape element as described in claim 1, wherein the circles defining the five arcs are inscribed circles in pairs, the first circle (C1) defining the first arc (A1) is inscribed in the second circle (C2), the second circle (C2) defining the second arc (A2) is inscribed in the third circle (C3), the third circle (C3) defining the third arc (A3) is inscribed in the fourth circle (C4), and the fourth circle (C4) defining the fourth arc (A4) is inscribed in the fifth circle (C5) defining the fifth arc (A5), and the inscribed circles define a series of different tangent points (T1, T2, T3, T4). An aerodynamically symmetrical profile element as described in claim 1, wherein, in a cross-section perpendicular to the symmetry plane (12) of at least part of the profile element (1, 2, 3, 4), the aerodynamic profile (15) has at least 95% of the central portion of the sage leaf profile, and the ratio between the maximum spacing (E) measured perpendicular to the vertical symmetry plane (12) and the maximum chord (C) measured in the vertical symmetry plane (12) is between 0.2 and 0.25. An aerodynamically symmetric profile element as described in claim 1, wherein the profile element (1, 2, 3, 4) is at least partially hollow. An aerodynamically symmetrical profile element as claimed in claim 1, wherein, relative to the perpendicular symmetry plane (12) of the vehicle (V) for resting on the horizontal rolling plane (H) with its plurality of wheels, the profile element (1, 2, 3, 4) has at least: * a first portion of the profile element (3), between, on the one hand, a lower cutting plane (P1) of the profile element (3) and, on the other hand, a first intermediate cutting plane (P2) of the profile element (3), the lower cutting plane (P1) being parallel to the horizontal rolling plane (H), the first intermediate cutting plane (P2) of the profile element (3) being parallel to the lower cutting plane (P1), and * the second part of the profile element (3), between, on the one hand, the first intermediate cutting plane (P2) or a possible second intermediate cutting plane parallel to the lower cutting plane (P1) but different from the first intermediate cutting plane (P2) and, on the other hand, an upper cutting plane (P3) of the profile element (3), the upper cutting plane (P3) being parallel to the lower cutting plane (P1), wherein the first intermediate plane (P2) extends between the lower cutting plane (P1) and the upper cutting plane (P3), and the optional second intermediate cutting plane extends between the first intermediate cutting plane (P2) and the upper cutting plane (P3); wherein, for each cutting plane parallel to the lower cutting plane (P1) between the lower cutting plane (P1) and the first intermediate cutting plane (P2), the first portion of the profile element (3) has, on the one hand, a substantially constant sage leaf profile with a chord (C) measured in the vertical plane of symmetry (12), and, on the other hand, a substantially constant maximum spacing (E) measured perpendicular to the vertical plane of symmetry (12), having a ratio between the maximum spacing (E) measured perpendicular to the vertical plane of symmetry (12) and the maximum chord (C) measured in the vertical plane of symmetry (12) between 0.1 and 0.3, advantageously between 0.1 and 0.25, preferably between 0.2 and 0.25; Wherein, preferably, the second portion of the profile element (3) has, for each cutting plane parallel to the lower cutting plane (P1) between the first intermediate cutting plane or the second intermediate cutting plane and the upper cutting plane (P3): * a continuously varying sage leaf profile between the following two - a maximum sage leaf profile along the first intermediate cutting plane or the second intermediate cutting plane (P2) having a maximum chord (C) measured in the vertical symmetry plane (12) and a maximum spacing (E) measured perpendicular to the vertical symmetry plane (12), and - a minimum sage leaf profile along the upper cutting plane (P3) having a minimum chord (C') measured in the vertical symmetry plane (12) less than the maximum chord (C) and a minimum spacing (E') less than the maximum spacing (E), Each sage leaf section has a ratio between the spacing (E, E') measured perpendicular to the symmetry plane/the chord (C, C') measured in the symmetry plane (12) between 0.1 and 0.3, advantageously between 0.1 and 0.25, preferably between 0.2 and 0.25. An aerodynamically symmetrical profile element as claimed in claim 1, wherein the vehicle (V) is in an upright position with the wheels resting on a horizontal plane (H), the profile element having: - a vertical plane of symmetry (12) and - at least one portion extending between a first horizontal plane perpendicular to the vertical plane of symmetry (12) and a second horizontal plane perpendicular to the vertical plane of symmetry (12), the portion being characterized by a substantially constant horizontal section substantially similar to that of a sage leaf, the substantially constant horizontal section being defined as having substantially the same length of the chord (C) measured in the vertical plane of symmetry (12) and substantially the same spacing (E) measured perpendicular to the vertical plane (12). A frame (20) of a bicycle (V) suitable for supporting at least one front wheel (21) and one rear wheel (22), the frame (20) comprising at least: (a) a saddle profile (23) having a lower end (23A) and an upper end (23B) suitable for supporting a saddle post (24), (b) a control profile (25) suitable for receiving a control lever (26), the control lever (26) being associated with at least a fork (27) and a handlebar (28) for the front wheel (21), (c) a diagonal profile (1) connecting the lower end (23A) of the saddle profile (23) to the control profile (25), and advantageously (d) connecting the upper end (23B) of the saddle profile (23) to the substantially horizontal profile (2) of the steering profile (25), The frame (20) is advantageously associated with at least a seat stay (31) and a chain stay (29) suitable for supporting the rear wheel (22), and/or with a fork (27) for the front wheel (21), and/or a front fender (30) suitable for at least partially covering the upper part of the front wheel (21), and/or a rear fender (3) suitable for at least partially covering the upper part of the rear wheel (22) and/or to a cap (4), The basic feature of the frame is that at least one element selected from the saddle profile (23), the steering profile (25), the diagonal profile (1), the optional substantially horizontal profile (2), the possible front fender (30), the possible rear fender (3) and the possible cap (4), possible combinations thereof, is an aerodynamically symmetrical profile element as in one of claims 1 to 6. A frame as described in claim 7, wherein the diagonal profile (1), the saddle profile (23) and optionally the horizontal profile (2) are integrated in the same aerodynamically symmetrical profile element. A bicycle (V) comprising a frame as described in claim 7 or 8. The bicycle (V) as described in claim 9, when it is in an upright position with the wheels placed on a horizontal plane (H), the aerodynamically symmetrical shape element (3) of at least one element selected from the saddle shape (23), the steering shape (25), the diagonal shape (1), the optional substantially horizontal shape (2), the optional front fender (30), the optional rear fender (3) and the optional cap (4), optionally in combination with each other, has at least one portion having a sage leaf profile in a horizontal section as defined for the aerodynamically symmetrical shape element. A use of a wheeled vehicle suitable for moving on the earth at a speed of less than 100 km/h in a horizontal plane, the vehicle being in particular a bicycle (V) as described in claim 9 or 10, the vehicle comprising at least one aerodynamically symmetric element profile as described in any one of claims 1 to 6, in particular at least one frame as described in claim 7 or 8, for generating at least one motor force between 2N and 10N in the direction of travel of the vehicle by the effect of wind on the at least one aerodynamically symmetric element profile for a wind speed of at least between 10 km/h and 80 km/h with an angle of attack or angle of incidence relative to the direction of travel of the vehicle of at least between 10° and 170°.

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