US20140298570A1

US20140298570A1 - Cycling helmet with high aerodynamic efficiency

Info

Publication number: US20140298570A1
Application number: US14/243,942
Authority: US
Inventors: John Cobb
Original assignee: RUDY PROJECT SpA
Current assignee: RUDY PROJECT SpA
Priority date: 2013-04-03
Filing date: 2014-04-03
Publication date: 2014-10-09
Also published as: ITPD20130082A1

Abstract

An aerodynamic cycling helmet is described, comprising a shell developed along a longitudinal direction, from a front area to a rear area, the said rear area extending beyond an inner portion of the shell provided with an occipital support of the head, the said shell being symmetrical with respect to a longitudinal plane of symmetry containing the longitudinal direction and extended in two opposing side walls from a temporal area and the area of the ear to the rear area. On each of the side walls, the helmet is provided with a respective air intake, which is open and passing through the shell and the shell includes in the rear area, within the shell, respective surfaces for channelling the flow of air that are capable of straightening, parallel to the longitudinal direction, the air flow derived from each of the air intakes and of channelling the flow, within the shell, in the direction of the rear area of the shell.

Description

FIELD OF THE INVENTION

The present invention relates to a cycling helmet with high aerodynamic efficiency.
The invention falls within the technical scope of protective helmets for cycling, particularly in the specific field of helmets designed for speed races, including, for example, so-called time trials and the cycling competitions involved in the Triathlon event.
In this context, helmets are designed to perform two main functions, namely to provide adequate protection of the cyclist's head against falls or knocks and to reduce as far as possible the aerodynamic resistance to progress, by attempting to achieve the maximum aerodynamic efficiency. In addition to these main qualities, the helmet must also provide appropriate ventilation to the areas of the cyclist's head that are protected by the helmet, in order to obtain a corresponding adequate level of comfort during the conduct of the sport.

BACKGROUND

In order to achieve the properties described above, the structure of such helmets is often the result of a compromise between characteristics that are not easily reconciled. For example, while the presence of apertures created through the shell of the helmet encourages ventilation, such a structure does not allow a high aerodynamic efficiency to be obtained, due to the surface discontinuities produced on the shell by the presence of the apertures in the helmet, which increase the coefficients of drag. On the other hand, surface conformations of the helmet specifically designed to maximise the aerodynamic coefficients, by combining surface continuity of the shell with special curvatures of the same, in order to minimise resistance to progress, are often in conflict with the need to ensure suitable comfort of fit and ventilation inside the helmet.
In the field of helmets designed for speed races or for cycling races in which the need to try to increase aerodynamic efficiency is of the first importance, one of the main problems encountered is limiting the turbulence of the air in the rear area of the helmet, where—due to the system of pressures induced by the dynamics of the air flow that streams over the surface of the helmet—instabilities are generated in the layers of the air current by the presence of turbulences and vortices, producing a loss of aerodynamic efficiency, which is reflected negatively in the cyclist's performance results. What is more, given the high speeds that the rider can reach in races of this type, the resistances and losses of aerodynamic efficiency can reach levels that significantly affect the performance results.

SUMMARY

The main aim of the invention is to provide a cycling helmet structurally and functionally designed to achieve an improved aerodynamic efficiency with respect to the traditional solutions, overcoming the limits encountered with reference to the cited prior art, while simultaneously providing the helmet structure with suitable protection and ventilation capacity for the practice of cycling disciplines, and particularly for speed cycling.
The invention achieves this and the other aims set out below.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics and advantages of the invention will be made clearer by the following detailed description of a preferred embodiment, given by way of non-limiting example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a cycling helmet realised according to the invention,

- FIG. 2 is a side elevation view of the helmet shown in FIG. 1,
- FIG. 3 is a plan view of the top of the helmet shown in the preceding figures,
- FIG. 4 is an elevation view of the back of the helmet shown in the preceding figures,
- FIG. 5 is a plan view of the bottom of the helmet shown in the preceding figures,
- FIG. 6 is a perspective view of the helmet shown in the preceding figures, with a first accessory attached to the same, and
- FIGS. 7 and 8 are respectively a side elevation view and a frontal view of the helmet according to the invention, with other accessories fitted to the same.

DETAILED DESCRIPTION

Embodiments of the invention will now be described. The following detailed description of the invention is not intended to be illustrative of all embodiments. In describing embodiments of the present invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.
With reference to the above figures, the numeral 1 marks a cycling helmet with high aerodynamic efficiency, realised according to the present invention.
The helmet 1 comprises a shell 2, whose thickness is defined between opposing inner and outer surfaces of the shell, respectively marked as 2 a and 2 b, the shell's inner surface 2 a being capable of wrapping around a substantial portion of the user's head.
The shell 2 is developed along a longitudinal direction, marked X in the plan view shown in FIG. 3, from a front area 3 to a rear area 4 (which extends to the level of the user's shoulders with the helmet in place), the said rear area 4 extending beyond an inner portion 5 of the shell provided with an occipital support 6 of the head. The said support 6 is conveniently of the adjustable type and are integrated, in a manner known per se, into a strap fastening system 7 with tightening in the area of the chin-strap.
The shell 2 is made symmetrical with respect to a longitudinal plane of symmetry, indicated by S and containing the longitudinal direction X (in the plan view of FIG. 3, the plane of symmetry S is perpendicular to the plane of the sheet, as well as containing the X-axis).
The shell 2 is extended in two opposing side walls 2 c, 2 d, each of which is extended from a temporal area and the area of the ear to the rear area 4.
With reference to FIG. 3, the shell 2 also has a transverse cross-section of greatest dimension transverse to the longitudinal direction X, such cross-section being defined by the intersection of a transverse plane M running perpendicular to the longitudinal plane S and perpendicular to the longitudinal direction X.
On each side wall 2 c, 2 d, the helmet is provided with a respective air intake 8 a, 8 b, which is open and passing through the shell and is located in an area of the shell between the transverse cross-section of greatest dimension and the rear portion of the shell (FIG. 3), essentially behind the occipital support area (FIG. 5). The profile of the cross-section of each of the air intakes 8 a, 8 b develops preferably in a plane running essentially at right-angles to the longitudinal direction X.
The air intakes 8 a, 8 b are designed, as will be explained in greater detail below, to collect a volume of air that runs into the helmet laterally and to channel this volume of air, within the shell, into the rear area 4 of the helmet, straightening the flow lines of the air predominantly along the longitudinal direction X, in order to improve the aerodynamic efficiency of the flow in the rear area of the helmet.
To this end, in the rear area 4, inside the shell 2, air flow channelling surfaces are provided that are capable of straightening, parallel to the axial direction X, the air flow derived from each of the intakes 8 a, 8 b, and of channelling this flow, along the inner surface 2 a of the shell, in the direction of the rear area 4, so as to impart to the current of the flow, as it exits the shell, a directional component that is predominantly axial, parallel to the axial direction X. For explanatory purposes, FIG. 5 shows in schematic form the progress of some lines of flow of the air current that impinges on the helmet, their deviation at the openings of the air intakes, and the straightening effect to which they are subjected, induced downstream of the air intakes, until they exit the helmet in the rear area.
In detail, identified within the shell, starting from each of the air intakes 8 a, 8 b, is a respective surface portion 9 a, 9 b for channelling the air flow, derived from the corresponding air intake, in the direction of the rear area 4, cooperating, in the function of straightening the air flow, with a directional tailpiece 10, which is provided at the centre of the rear area of the shell. The said tailpiece 10 is erected from the inner surface 2 a of the shell and has a symmetrical shape with respect to the plane of longitudinal symmetry S. The labels 10 a, 10 b mark opposing faces of the tailpiece 10, developed parallel to the plane S, each of the said faces cooperating with the corresponding channelling surface portion 9 a, 9 b facing the same, to straighten the air flow derived from the intake and send it to the exit from the helmet, in the rear area, with a predominantly axial direction.
In this manner, an air flow with a predominantly axial direction is sent beyond the rear area of the helmet, in the region of the cyclist's shoulders, with a speed and volume different from those that characterise the traditional air flow that streams over the helmet in the said rear area. This rear area is usually characterised by strong instabilities and turbulences in the flow, due to the effect of the low pressure states induced by the air flow dynamics generated by the presence of the helmet, and this instability also produces vortices, with consequent losses of energy and aerodynamic efficiency. This instability is countered by channelling straightened air into the said area; the air is taken in upstream, through the air intakes of the helmet, and is channelled by the flow straightening system described above.
The system described, which combines the effect of the lateral air intakes with that of the directional tailpiece and the surface portions channelling the air inside the shell, performs two main functions.
The first and primary function is to straighten the flow directed into the rear part of the helmet, in order to limit turbulence and eliminate the vortices produced in this area, allowing the straightened flow to reach the shoulder region by stabilising the current, with a consequent improvement of aerodynamic efficiency.
A second function can also be identified in the improved internal ventilation of the helmet, which is brought about by the flow straightening system. Thanks to the presence of pressure differentials that are created starting from the flow pick-up area of the air intakes, in the direction of the rear area of the helmet, the resulting accelerations of the air flow enhance the ventilation inside the helmet, thus improving the evaporation of sweat and perspiration in general.
Returning to the structure of the straightening system, with particular reference to FIG. 3, each surface channelling portion 9 a, 9 b has a surface profile, both at the inner surface 2 a and the outer surface 2 b, that diverges from the course of the rest of the shell profile contiguous with it. For example, in the plan view shown in FIG. 3, starting from the air intake, the extrados profile in the channelling area 9 a, 9 b diverges from the course of the contiguous shell profile (indicated by a dashed line in the figure), and extends away from the latter to the rear area 4. In this area, thanks to the projecting shape of the surface portions 9 a, 9 b with respect to the rest of the shell profile, the said portions define, together with the directional tailpiece 10, a shell outlet section 2 for the air flow derived from the intakes 8 a, 8 b and straightened by the straightening system described. The rear outlet section may also be formed with a pair of recesses 12, symmetrical with respect to the plane of symmetry S and defining a sort of outlet port for the straightened flow in the rear area of the helmet (FIG. 4).
In addition, the profile of the extrados surface (belonging to the outer surface 2 b of the shell) of each of the channelling surface portions 9 a, 9 b is preferably conceived as a wing profile, for example of the type prescribed according to the NACA classification, in order to improve the aerodynamic efficiency of the said surface.
The label 15 also marks an extension element of the directional tailpiece 10, which may be removably attached to the tailpiece, as an extension of the free extremity of the tailpiece, if it is desirable to increase the breadth of the corresponding opposite faces of the tailpiece 10 (FIG. 6).
The labels 20 a, 20 b mark a pair of ventilation apertures provided in the front area 3 of the helmet. The said apertures are formed through the thickness of the shell 2 and are made symmetrical to each other with respect to the plane of symmetry S. Conveniently, the apertures 20 a, 20 b may be capable of being selectively shut off by a closure element 21, capable of being removably attached to the helmet, fitting over the apertures. The said closure element 21 has a shape such that it is flush with the outer surface 2 b of the shell, when attached to close the ventilation apertures.
A second pair of ventilation apertures 22 a, 22 b is provided in the rear area 4 of the helmet, as clearly shown in FIG. 4. The apertures 22 a, 22 b are also formed through the thickness of the shell 2 and are symmetrical to each other with respect to the longitudinal plane of symmetry.
The label 25 marks a dorsal ridge developed centrally on the outer extrados surface 2 a of the shell 2, at the crown of the shell, running continuously along the longitudinal direction X, from the front anterior area 3 to the rear area 4. The structure of the ridge 25 is also symmetrical with respect to the longitudinal plane of symmetry S. Such a dorsal ridge, which offers low frontal resistance to progress, is advantageous for converting lateral stresses (due, for example, to side winds hitting the helmet) into stresses with components directed predominantly along the longitudinal direction, which are favourable to the overall aerodynamic efficiency of the helmet.
Finally, the label 30 marks a visor capable of being removably attached to the helmet in the front area of the same and conveniently realised as a mono-lens mask. The visor 30 may, alternatively, be conceived as a mask realised with a double-lens structure, with an inner and an outer lens sandwiched together, in which the lenses extend over the entire forward field of vision.
The invention thus achieves the established aims, affording the described advantages with respect to the known solutions.
In particular, it provides the main advantage that can be achieved with the invention, aimed at improving the stability of the air current in the rear area of the helmet, which is subjected to fluid dynamic perturbations by the presence of the helmet itself and the cyclist's neck and shoulders, by eliminating the turbulences and vortices induced in this area by the fall in pressure in the layers of air that stream over the rear area of the helmet.
While the invention herein disclosed has been described in specific embodiments and applications thereof, numerous modifications and variations can be made thereto by those skilled in the art without departing from the scope of the invention.

Claims

1. An aerodynamic cycling helmet comprising a shell developed along a longitudinal direction (X), from a front area to a rear area, the rear area extending beyond an inner portion of the shell provided with an occipital support of the head, the shell being symmetrical with respect to a longitudinal plane of symmetry (S) containing the longitudinal direction (X) and being extended in two opposing side walls extending from a temporal area and the area of the ear to the rear area, the shell having a transverse cross-section of greatest dimension transverse to the longitudinal direction, such cross-section being defined by the intersection of the shell with a plane (M) perpendicular to the longitudinal plane of symmetry (S) and perpendicular to the longitudinal direction (X), -comprising on each of the side walls, a respective air intake, which is open and passing through the shell, located in an area of the shell between the transverse cross-section of greatest dimension and the rear portion of the shell, essentially behind the occipital support area, and by the fact that the shell comprises in the rear area, and within the shell, respective surfaces for channelling the flow of air, capable of straightening, parallel to the longitudinal direction (X), the air flow derived from each of the intakes and of channelling this flow, within the shell, in the direction of the rear area of the shell, so as to impart to the current of the flow, as it exits the shell, a directional component that is predominantly axial, parallel to the longitudinal direction (X).

2. The cycling helmet according to claim 1, wherein, starting from each of the air intakes and extending in the interior of the shell, there is a respective surface portion for channelling the air flow, derived from the corresponding air intake, in the direction of the rear area, cooperating, in the function of straightening the air flow, with a directional tailpiece provided at the centre of the rear area of the shell, the tailpiece having a symmetrical shape with respect to the plane of longitudinal symmetry (S) and comprising opposing faces developed parallel to the plane of symmetry (S), each of the faces cooperating with the corresponding channelling surface portion facing it, to straighten the air flow derived from the corresponding air intake as it exits the rear area of the helmet.

3. The cycling helmet according to claim 2, wherein each channelling surface portion has an extrados surface profile that diverges from the course of the shell profile contiguous with it, starting from the corresponding air intake in the direction of the rear area, so as to define, in the rear area of the shell, together with the directional tailpiece, the shell outlet section for the air flow derived from the corresponding air intake and straightened by the channelling surfaces.

4. The cycling helmet according to claim 3, wherein the profile of the extrados surface of each of the channelling surface portions is conceived as a wing profile, of the type prescribed according to the NACA classification.

5. The cycling helmet according to claim 1, wherein the sectional profile of each of the air intakes develops in a plane perpendicular to the longitudinal direction of extension (X) of the helmet.

6. The cycling helmet according to claim 2, comprising an extension element of the directional tailpiece, which is removably attached to the tailpiece at its free extremity, to increase the surface breadth of the corresponding faces of the directional tailpiece.

7. The cycling helmet according to claim 1, comprising in the front area of the shell at least a first pair of ventilation apertures, passing through the thickness of the shell and made symmetrical with respect to the longitudinal plane of symmetry (S), the ventilation apertures being capable of being selectively shut off by a closure element capable of being removably attached to the ventilation apertures.

8. The cycling helmet according to claim 7, wherein the closure element has a shape such that it is flush with the outer surface of the shell, when attached to close the ventilation apertures.

9. The cycling helmet according to claim 7, wherein there is a second pair of ventilation apertures, passing through the thickness of the shell, provided in the rear area of the shell, symmetrical with respect to the longitudinal plane of symmetry (S).

10. The cycling helmet according to claim 1, including on the extrados surface of the shell a dorsal ridge extending longitudinally from the front anterior area in the direction of the rear area, which has a symmetrical shape and arrangement with respect to the longitudinal plane of symmetry (S) of the helmet.

11. The cycling helmet according to claim 1, wherein provision is made for a visor capable of being removably attached to the front area of the shell. to 12. The cycling helmet according to claim 8, wherein there is a second pair of ventilation apertures, passing through the thickness of the shell, provided in the rear area of the shell, symmetrical with respect to the longitudinal plane of symmetry (S).