WO1995020887A1

WO1995020887A1 - Crash helmet with improved fixing system and safety locking system of the visor

Info

Publication number: WO1995020887A1
Application number: PCT/IT1995/000011
Authority: WO
Inventors: Franco Malenotti
Original assignee: Dainese S.P.A.
Priority date: 1994-02-03
Filing date: 1995-01-27
Publication date: 1995-08-10
Also published as: EP0741528A1; IT1271848B; ITRM940049A1; ITRM940049A0; AU1589295A

Abstract

A crash helmet for motor-cyclists with a visor fixing system made up by an annular projection (9) integral with the visor (8), two recesses (11a, 11b) formed on said annular projection (9), and two fins (12a, 12b) integral with the base element (2) mounted on the crash helmet. A cover element (13) is mounted on the base element (2) by means of sliders (14a, 14b) engaging respective seats obtained on the base element. The cover element has a limit stop which prevents the visor from rotating to the position in which the fins (12a, 12b) are aligned with the recesses (11a, 11b), because in that case the annular projection (9) would detach itself from the circular groove (10) of the base element (2). The crash helmet has also a safety locking system of the visor and a ventilation system, which are both improved.

Description

Crash helmet with improved fixing system and safety locking system of the visor

Technical Field

The present invention relates to an improved fixing system for the visor of a motor-cyclist's crash helmet, which is particularly easy to handle and does not make use of specific fixing means such as screws or the like. The invention relates also to a safety locking system for the visor, an air ventilation system - by extraction of air -, and to an inner protection element of the stationary internal coating, which is removable for washing purposes.

Background Art

As known, the motor-cyclist is often forced to remove the visor, in order to substitute it with one which has different properties. For instance, during the summer it is necessary to mount a visor having a darker screen, whereas in winter one commonly uses tarnishing preventing visors.

This replacement requires - for conventional type crash helmets - to release complicated fixing systems, and possibly to unscrew one or several screws.

Moreover, the motor-cyclist often desires only to adjust the position of the visor with respect to the shell, and he dislikes to be compelled to remove the visor completely. It is therefore particularly useful to develop a system, by means of which the adjustment of the visor's position is performed without being forced to remove the same.

With regard to safety locking systems for the visor, it is known, that the visor may accidentally lift itself due to air turbulence, if such systems are not employed, when the motor-cyclist lifts or laterally moves his head. It will also be necessary to press the visor firmly against the seal, in order to prevent the entrance of air draughts or water droplets which would affect the motor-cyclist's concentration. In the past a slider has often been used for that purpose, or any other manually operated element, which by engagement, locked the visor. This system required a certain effort from the motor-cyclist, who was forced to remove his hand from the handle for a non-negligible period of time. It is therefore understandable that such systems using a slider have a reduced functionality and are dangerous.

Another problem to be faced, is that of developing an effective ventilation system of the inner region of the crash helmet, which nevertheless prevents entrance of water droplets, and which eliminates noise produced by air draughts, when the system is deactivated by the motor-cyclist. In fact, the necessity of ventilating the inside of crash helmets by drawing the warm air to the outside, thereby limiting an excessive perspiration expecially in the summer, is well known. An excessive perspiration lowers the comfort and concentration of the motor- cyclist, and consequently reduces driving safety. In conventional systems there are provided frontal apertures allowing air to enter, which are generally located on the upper part of the crash helmet and on its lower part, and/or similar apertures on the rear part in order to draw (extract) air to the outside.

Said apertures are usually protected by small doors of various kinds, mostly slidable and operated by the finger's tip. Conventional ventilation systems have the following drawbacks:

- reduction of the crash helmet's safety due to protrusions of the small doors or to actuation levers thereof, which in case of falling, may engage or get in contact with some object on the ground, thereby limiting the correct and necessary sliding of the crash helmet;

- entrance of water through the apertures, which soakes the inner stuff;

- entrance of air, even when the small doors are closed, thereby increasing the noise; - entrance of air jets, directly impinging on the head, at small velocities, and an almost inexistent air flow towards the inside, due to the funnel effect when the motorcycle is moving at large velocities; - worsening of the aerodynamic properties of the crash helmet, due to the protrusions of the small doors and to the infiltrations;

- the apertures on the rear part have no drawing effect, because of air turbulences in this zone caused by the detachment of fluid filaments from the crash helmet's surface.

These turbulences limit the drawing effect, and the air, most often, instead of flowing outwards, will tend to enter in those apertures.

Disclosure of Invention

It is an object of the present invention to eliminate the foregoing disadvantages of the prior art of manufacturing crash helmets for motor-cyclist.

Further advantages of the invention, as regards the cleanness inside the crash helmet, will result from the following description.

Brief Description of Drawings

The present invention will now be described for illustrative and non-limitative purposes, with reference to the annexed drawings, in which:

Fig. 1, is an exploded perspective view of a possible embodiment of the present invention, which shows the improved fixing system of the visor, and the safety locking system; Fig. 2, is an enlarged scale view of two details of Fig. 1?

Fig. 3a shows the air ventilation system according to the present invention;

Fig. 3b is a cross sectional view along the line A-A of Fig. 3a;

Fig. 3c is a cross sectional view similar to Fig. 3b, but with the channel for air circulation adjacent to the external rigid shell;

Fig. 4 shows the crash helmet of the present invention, having on its inside wall a spheroidal fabric-made protection element, which is replaceable and washable.

Best Mode of carrying out the Invention

With reference to Figs. 1 and 2, the base element 2 is mounted on the shell 1 by means of bushings 3a, 3b - passing through holes 4a, 4b -, washers 5a, 5b, and screws 6a, 6b inserted in the bores 7a, 7b of the base element 2. The visor 8 - whose only portion shown is that being mounted on the base element 2 -, is introduced into circular guide 10 of the base element 2, by means of its annular projection 9, the latter being provided with recesses or interruptions 11a, lib. For that purpose, the visor 8 is rotated by an angle such that the two recesses 11a, lib are aligned with the fins 12a, 12b which are integral with the base element 2. Once the visor 8 has been inserted, it can be lowered making it slide along the circular guide 10 without being capable of detaching itself, due to the fact that it is held in place by the fins 12a, 12b. In order to prevent the two recesses 11a, lib from being aligned once again with the fins 12a, 12b, thereby causing a possible accidental separation of the visor, the cover element 13, which is fixed by means of the sliders 14a, 14b to the base element 2, through their seats 51, 52, is provided with a limit stop which prevents the visor from reaching that lifted position corresponding to a theoretical maximum rotation angle, in which the fins 12a, 12b are again in front of the recesses 11a, lib. The limit stop (not shown) integral with the cover element 13, therefore prevents the visor to be lifted still further, by a small additional angle of some degrees, beyond the maximum aperture angle, when the visor is mounted on the shell of the helmet and is in an operative condition. In order to mount the cover element 13 on the base element 2, it is only required to push the sliders 14a, 14b in the outward direction along the guides 15a, 15b, engaging their lower parts 16a, 16b with the base element 2, inside the seats 51, 52. For the removal of the visor, the inverse operations are performed.

The system just described is very easy to use, and it also allows to adjust the position of the visor without being forced to remove the same.

It will in fact suffice to remove only the small cover element 13 after having displaced the sliders 14a, 14b towards its centre, and adjust the position of the base element 2 by loosening the screws 6a, 6b. The base element 2 can move upwardly, downwardly, and laterally, and be fixed in the desired position, by providing slots 7a, 7b having adequate dimensions, and a desired diameter of the stem of the screws 6a, 6b. Hereinafter, the safety locking system of the present invention will be described with reference to Fig. 2.

The helicoidal spring 17 lodged in the space 18 together with the upper pawl 19, is inserted on the pin 20a, integral with the base element 2, at its end 21a, whereas at its opposite end 21b, it is inserted on the pin 20b, integral with the upper pawl 19.

The upper pawl 19 is slidable along the lateral walls of the space 18, and it engages upwardly with the teeth 22 formed on the annular projection 9 of the visor 8. The user, while lifting or lowering the visor 8, will hear several clicks, which correspond to different positions of the upper pawl 19 along the teeth row 22. Said clicks will stop the visor in intermediate positions. The safety locking system comprises the lower helicoidal spring 23 and the lower pawl 24 , which has a circular protrusion 25 introduced into the space 26 adjacent to the space 27 containing the pin 28, integral with the base element 2.

Said pin 28 is located on the upper wall of the space

27.

The lower pawl 24 has a pin 29, and the helicoidal spring 23 is introduced in the space 27 ; the two ends of the helicoidal spring 23 being respectively inserted on the pin 29 of the lower pawl 24 and on the pin 28 of the base element 2.

The lower pawl 24 acts like a lever with its fulcrum at the point 25 forming a circular projection introduced into the space 26.

The lower pawl 24 does not engage the inclined surface 30 and the concavity 31 for most of the rotational movement of the visor 8, when said visor is being lowered. Only during the last phase of said rotational movement, the lower pawl 24 is forced to "climb up" the inclined surface 30 forming a single moulded part with the annular projection 9, whereafter it will engage the concavity 31 formed on said annular projection 9, at the time when the visor 8 reaches its closure position. Due to the spring 23, the lower pawl 24 forces the visor to remain in the closure position, and, moreover, by adequately choosing the shape of the concavity 31 , it is possible to force the visor, i.e. press it, against the seal, due to the effect produced by the spring 23, thereby obtaining a perfect seal. In order that the lower pawl 24 may engage the concavity 31, by means of its protrusion 32, it will be sufficient to exert a pressure on the visor 8, by the hand, so that it will reach the closure position. This requires a minimum time interval for a motor-cyclist.

The lower pawl 24, presses the visor against the seal, since the protrusion 32 of the pawl, slides along the wall of the concavity 31 without touching its bottom, and because of the combined action of the spring 23 and of the lever embodied by the lower pawl 24. In Figs. 3a and 3b, the improved ventilation system of the present invention is shown. With particular reference to Fig. 3b, representing an orthogonal section of the shell along line A-A, of a small portion thereof according to Fig. 3a, the inner polystyrene layer is formed of two parts, i.e. an upper part 33 and a lower part 34. The hatched part 36 indicates the external rigid part of the crash helmet, in plastic and/or fibers. The division in two parts of the shell-like polystyrene layer is known in the art, and is used by crash helmet manufacturers mainly for the purpose of differentiating two parts with different densities.

The upper part 33 and the lower part 34 (see also Fig. 3a) are separated from each other by a channel 35 which may be formed indifferently in the upper part 33 or in the lower part 34. In Fig. 3b the channel is realized in the lower part 34 of the polystyrene layer. The channel may be located along the middle line of the shell-like polystyrene layer, but also in other parts, as for instance the edge, towards the rigid shell (reference number 35' Fig. 3c ) .

The channel 35 bounds the two parts 33, 34 of the inner polystyrene coating and extends around the crash helmet (obviously in its inside), as shown in Fig. 3a, forming a closed curve, which naturally follows the junction region between the two parts 33, 34 of polystyrene. Moreover, along the whole channel 35, there are provided small holes or slots 37 which are spaced apart from each other and are obtained in the lower part 34 or in the upper part 33, according to whether the channel 35 is formed in the lower part 34 (as shown) or in the upper part 33 of the polystyrene layer. The holes oriented towards the inside are therefore radial holes located around the user's head. The channel 35 communicates with the bore 38 obtained on the external shell of the crash helmet, and is aligned with the bore 39 of the base element 2, which is also aligned with a bore 40 formed on the cover element 13 (Fig. 1). The slider 41 of the cover element 13 closes or opens the bore 40 according to its position on the cover element.

It is obvious that all elements of Fig. 1 are present on both sides of the crash helmet. Therefore, the channel 35 communicates with the atmosphere at the site of the bores 40 , the latter ones being located at a point where the air velocity is greatest and its pressure is a minimun and moreover, where no kind of turbulence is present. This result is known in fluid dynamics.

In fact, for a two dimensional potential motion, one has: p + 1/2 - oV² = const (p = pressure, e = density, V = fluid velocity). Therefore, if the velocity increases, the pressure of the fluid decreases at a specified point. This is true also in three dimensions.

For example, if a sphere is placed in a fluid mass which impinges on it at a velocity V₀ , the fluid flowing laterally and in a tangential direction with respect to the sphere has a velocity equal to V = 3/2 ^• V₀ and its pressure at this point is a minimum.

If one plots a polar diagram having its origin at the centre of the sphere, by indicating the value of the overpressure p-p₀ in the diagram outside of the sphere, if positive, or inside, if negative, he will recognize - that the surface of the polar diagram intersects the surface of the sphere at points in space such that the straight line connecting them to the centre of the sphere, forms an angle of about 41^c, 50' with the direction of the velocity V_Q .

Since inside the crash helmet the air pressure p_^ is equal to the atmospheric pressure, due to the fact that this inner region is a "still zone", there results a drawing (extraction) effect which eliminates (warm) air from the inside of the crash helmet, and moreover, this effect is not disturbed by air turbulences. As shown in Fig. 3a, the air is sucked from the inside of the crash helmet and passes through the holes 37 located along the channel 35, and thereafter, it reaches the two lateral bores 40 of the two cover elements 13, via said channel, and finally it is discharged to the atmosphere.

As can be seen in Fig. 3a, in order to direct the air towards the small holes 37 , ellipsoidal recesses 42 may be formed in the region of said small holes 37 on the two parts 33, 34 of polystyrene. In Fig. 3b, which is a cross section, the dotted line 43 represents the (ideal) continuation of the surface 44 which internally bounds the polystyrene layer. Fig. 3b shows the form of an ellipsoidal recess 42 in cross-section. The arrows 45 in Fig. 3 show how the air is conveyed by the ellipsoidal recesses 42.

Obviously the recesses 42 may have another shape, provided that they attain the object of conveying the air flow towards the small holes 37. The drawing effect is anyway present, event if the recesses are omitted.

The advantages which can be obtained by using this ventilation system are the following: - the lateral position of the ventilation apertures does not allow water to enter;

- the crash helmet has only two apertures or bores;

- there do not exist any sort of protrusions since the slider 41 has a flat form which is contained inside its guide track formed on the cover element 13;

- since air is only drawn (extracted) through the bores 38, 39, 40 on the two sides of the crash helmet, there are not air jets which directly impinge on the head, and which may be annoying;

- there are no air draughts or air infiltrations, which according to the prior art were due to the frontal position of the small doors where the pressure is greatest and enhances air infiltrations; - since the air exits are placed on the lateral region of the crash helmet, where the air pressure is a minimum and where no turbulences occur, the drawing effect is maximized. As mentioned at the beginning of the description, the present invention also comprises an inner protection and comfort element placed on the usual inner coating of the crash helmet.

Said protection element 50 is made of fabric, preferably cotton, and has a spheroidal form as shown in Fig. 4. Said protection element is fixed on the inner wall of the crash helmet, and may be easily removed for cleaning purposes.

Use of the protection element 50, and periodic cleaning of the same, prevents the possiblity that a not hygienical environment is established inside the crash helmet, due to absorption of the perspiration from the non-removable inner coating.

Claims

C laims

1. Crash helmet for motor-cyclists, comprising a fixing system for the visor, a safety locking system for the visor, an internal ventilation system, and an inner protection element which is removable and washable, characterized in that said fixing system comprises an annular projection (9) of the visor (8), with cavities or interruptions (11a, lib), and respective projections or fins (12a, 12b) integral with the base element (2) which is mounted on the crash helmet, said annular projection (9) being slidable below said fins (12a, 12b), inside an annular guide or groove (10) obtained on the base element (2) whereby a small cover element (13) is mounted to said visor (8) so as to prevent, by means of a limit stop integral with it, said fins (12a, 12b) to be again aligned with their corresponding cavities (11a, lib); said safety locking system comprising a lower pawl (24) which has a lower protrusion (32), said pawl (24) being continuously biased by a spring (23) against the annular projection (9) and locking the visor (8) in its closure position when the protrusion (32) of the pawl (24) , after having climbed up a slanted surface (30) , engages a concavity (31) obtained on the annular projection (9); the pawl (24) pressing the visor (8) against the seal of the crash helmet because of the fact that said protrusion (32) of the pawl (24) does not reach the bottom of the concavity (31) j said ventilation system comprising a channel (35) which is formed along the boundary line between a lower part (34) and an upper part (33) of the inner polystyrene coating, a plurality of through holes (37) disposed radially and which provide a communication between said channel (35) and the inside of the crash helmet, and a plurality of second lateral through holes (38, 39, 40), the first of them (38) being realized on the crash helmet's shell, the second (39), on the base element (2), and the third (40) , on the small cover element (13) , whereby said second through holes (38, 39, 40) are aligned and provide a communication between the inside of the channel (35) and the surrounding atmosphere; the inner protection element (50) being made of fabric, preferably cotton, having spheroidal shape, and being removable and washable.

2. Crash helmet for motor-cyclists according to claim 1, characterized in that said cover element (13) is locked on the base element (2) by means of sliders (14a, 14b) whose lower parts (16a, 16b) engage respective seats (51, 52) obtained on the base element ( 2 ) .

3. Crash helmet for motor-cyclists according to claim 1 or 2, characterized in that the spring (23) which biases the lower pawl (24) against the annular projection (9) of the visor (8) , is a helicoidal spring which is contained, together with the lower pawl (24) , inside spaces (26, 27) obtained in the base element (2).

4. Crash helmet for motor-cyclists, according to any of the preceding claims, characterized in that it comprised two pawls (19, 24) , an upper one (19) and a lower one (24) which provide an adjustment of the visor (8) , whereby the upper one (19) serves to define intermediate positions of the visor (8), and the lower one (24) serves to lock the visor in its closure position by pressing it at the same time against the crash helmet's seal.

5. Crash helmet for motor-cyclists according to any of the preceding claims, characterized in that said channel is realized indifferently on the upper part (33) or on the lower part (34) in a central position (35) , or in a lateral position (35') in the zone bounded by the shell (36) of the polystyrene coating, during moulding of said part.

6. Crash helmet for motor-cyclists according to any of the preceding claims, characterized in that said through hole (40) obtained on the cover element (13) may be opened or closed by a slider (41) which does not project out of the corresponding guide track obtained on the small cover element (13).

7. Crash helmet for motor-cyclists according to any of the preceding claims, characterized in that the annular projection (9) of the visor (8) has a teeth row (22) which engages an upper pawl (19) which slides along an upper space (18) obtained in the base element (2), being biased against said annular projection (9) by a second helicoidal spring (17) which is also lodged inside said upper space (18), the teeth row (22) allowing the locking of the visor (8) in an intermediate position with respect to the closure or completely open position.

8. Crash helmet for motor-cyclists according to claim 5, characterized in that along the channel (35) and at the site of said holes (37) of the channel (35), there are obtained various recesses (42) on the two parts (33, 34) of the polystyrene coating, said recesses (42) conveying the air inside the crash helmet towards said holes (37) and thus in the channel ( 35 ) .

9. Crash helmet for motor-cyclists according to any of the preceding claims, characterized in that said through holes (40) of the cover element (13) for discharging air to the atmosphere, are exactly located in the region where the velocity during the motion, of the air surrounding the helmet, is greatest and its pressure is a minimum.

10. Crash helmet for motor-cyclists according to any of the preceding claims, characterized in that the pressure exerted by the visor (8) on the seal of the crash helmet, can be adjusted by means of the force exerted by the helicoidal spring (23) associated to the lower pawl (24), whose protrusion (32) slides along the concavity (31) inside which said protrusion (32) will be located when the visor (8) is in its closure position, whereby said lower pawl does not reach the bottom of the concavity (31).

11. Crash helmet for motor-cyclists according to the preceding claims, characterized in that it is provided on its inside walls, i.e. on the inner coating, of an additional spheroidal protection element, which is removable and washable and serves for hygienical and comfort purposes, the crash helmet being possibly used without said protection element.

12. Crash helmet for motor-cyclists, characterized in that said through holes (37) are disposed in a radial direction around the head of the motor-cyclist.