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The present invention relates to a mechanism for attaching a visor to a motorcycling helmet. Below specific reference will be made to this application, but it is clear that the features described may also applied to other types of helmets, for example skiing or cycling helmets, and for attaching other types of elements to be mounted on the helmet, for example a chin guard.
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It is known that motorcycling helmets, especially in the off-road/motocross sector, may be provided with a removable visor or sun visor (peak) which has the function of protecting the user's face from sunlight, rain, mud, etc. Since the visor is subject to high stress levels due to the vibrations of the vehicle, the vertical accelerations, etc. typically associated with motorcycling riding, in particular off-road riding, it is important that the reversible attachment mechanism between the visor and the shell of the helmet should be able to ensure an adequate grip, in order to avoid undesirable separation of the visor, and a solid connection preventing play and vibrations during use.
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The systems of the prior art for ensuring a firm attachment typically involve the use of mechanical fixing devices, such as screws or automatic buttons, which pass through the visor and engage inside a corresponding seat, such as a threaded bush or a base, which is embedded in the shell of the helmet. Even though these solutions are able to provide a solid gripping action, they nevertheless have a number of drawbacks both during assembly/disassembly and during use.
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Firstly, in the case of screws, it is required to use a tool in order to assemble and disassemble the visor, and the strength of the connection depends on the tightening force and the skill of the person performing assembly. In fact, if not sufficiently tightened, the screw may come loose because of the vibrations and become detached from its female thread, while if overtightened, the thread may be subject to damage which complicates subsequent disassembly and reassembly.
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In the case of automatic buttons, a significant amount of pressure may be required to ensure a reliable connection, making the manual assembly and disassembly operations difficult for a user who is not very strong such as a woman or a child.
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Moreover, since in both cases, a base element embedded in the shell is envisaged, such a mechanism is costly to produce, results in the formation of a weak point in the shell, and involves the risk that, in the event of an impact, the base element may penetrate inside the shell, injuring the user. Furthermore, the use of metal elements increases the weight of the helmet and these elements may result, in the event of an impact, in acceleration peaks which are extremely dangerous for the user and generally may mean that the helmet is not type-approved. In fact, in the event of damage to the base element it is no longer possible to attach the visor because said element cannot be replaced.
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A possible alternative solution which avoids these drawbacks consists in attaching on the outside of the shell a hollow base which has, formed therein, a shaped hole for inserting a pin, with a correspondingly shaped end, which passes through the visor and has a head which comes into contact therewith. The space around the shaped hole, inside the wall of the base in which said hole is formed, allows the pin to be rotated in an engaged position of its shaped end in which the pin remains fastened to the base, thus attaching the visor to the shell.
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In this way, the manual assembly/disassembly operation is easier, the helmet is less costly, and there is no risk of the shell being penetrated by an element of the attachment mechanism. Moreover, the base may be replaced in the event of damage thereto, so that the visor may still be assembled.
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However, this solution also has a number of drawbacks since, in order to ensure a stable connection which prevents play and vibrations during use and avoids undesirable detachment of the visor, it is essential for there to be a very precise distance between the two contact surfaces of the pin, namely the bottom surface of the head which makes contact with the visor, and the top surface of the shaped end which makes contact with the base inner wall. In fact, a too large a distance will result in inadequate grip, while too small a distance will make attachment of the visor very difficult, if not impossible.
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Consequently, the production tolerances, not only of the pin, but also of the thickness of the visor and the base wall, must be very precise and compatible with each other in order to obtain the desired distance. Moreover, if even the required tolerances are respected, the sliding rotation of the shaped end against the base makes the assembly/disassembly operation difficult, with the risk of breakage of the pin owing to the excessive twisting torque in the event of very tight tolerances. Furthermore, the wear over time of the sliding surfaces, due to the vibrations and repeated assembly/disassembly operations, may result in a gradual deterioration of the attachment.
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The object of the present invention is to overcome the drawbacks of the mechanisms of the prior art for attaching a visor to a helmet. This object is achieved by means of a mechanism comprising an elastic element which pushes the pin outwards, and the pin is mounted on an actuating lever with respect to which it is rotationally constrained, but may slide axially in order to compress said elastic element.
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The main advantage of this mechanism lies in the fact of providing a solid attachment which is unaffected by the production tolerances and the wear over time, because it is the elastic element which ensures that the shaped element of the pin is constantly pressed against the inner wall of the base.
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A second significant advantage consists in the fact that, owing to the axial movement of the pin, the engagement of the shaped end may occur in a seat of the base which prevents the rotation thereof when it is in abutment, such that the mechanism is not subject to the loosening caused by the vibrations during use.
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Yet another advantage of this mechanism is that assembly and disassembly of the visor are simpler and quicker since, by pressing the pin in order to overcome the resistance of the elastic element, the shaped end moves away from the inner wall of the base and may rotate easily with the aid of the actuating lever, which has an arm much bigger than the radius of the pin head and therefore makes the operation much easier.
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It is pointed out that the base is a hollow base. In fact, it is pointed out that the aforementioned expression "inner wall of the base" implies that the base is hollow; in fact, otherwise there would be no inner wall.
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Further advantages and characteristic features of the mechanism according to the present invention will become clear to persons skilled in the art from the following detailed and non-limiting description of an embodiment thereof with reference to the accompanying drawings in which:
- Fig. 1 is a side view of a helmet with a visor positioned for attachment and the mechanism in the disengaged position;
- Fig. 2 is a enlarged, front, perspective view of a detail of the helmet according to Fig.1;
- Fig. 3 is a cross-sectional view of the mechanism along the line A-A of Fig.1;
- Fig. 4 is a front view of a helmet with the visor attached and the mechanism in the engaged position;
- Fig. 5 is an enlarged perspective view, from the inside, of a detail of the helmet according to Fig. 4; and
- Fig. 6 is a cross-sectional view of the mechanism along the line B-B of Fig.4.
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With reference to said figures, it can be seen that a helmet for motocross or similar activities comprises a shell 1 on which a visor 2 may be attached at a base 3 thereof. In particular, the aforementioned figures relate to the attachment mechanism on the left-hand side of the helmet, but a mirror-image mechanism is obviously present on the right-hand side of the helmet so that the description below is applicable to both mechanisms, mutatis mutandis. Moreover, the visor 2 is preferably attached also in the centre to the top of the shell 1, and this central attachment may be performed using a conventional pin-like mechanism or using a mechanism according to the invention as in the side attachments.
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The innovative aspect of the present mechanism, as mentioned above, consists in the fact that the mechanical fixing of the visor 2 is not performed simply using a pin which locks it onto the shell 1 engaging with the base 3, but it is envisaged using an actuating lever 4 which carries a pin 5 which is slidable axially with respect to the lever 4, but is constrained so as to rotate together therewith.
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Consequently, the shaped end 6 of the pin 5 is rotated between the position where it is inserted in the base 3, shown in Figures 1-3. and the engaged position, shown in Figures 4-6, by operating the lever 4 instead of acting directly on the head of the pin 5. Moreover, the visor 2 is locked on the base 3 not directly by the head of the pin 5, but by the lever 4 inside which the pin 5 is inserted.
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More specifically, in the preferred embodiment shown, the shaped end 6 consists of a separate element which is fixed onto the end part of the pin 5 by means of a screw 7. In this way, the mechanism may remain assembled on the visor 2 which has a through-hole suitable for receiving the pin 5, but which does not allow the shaped end 6 to pass through. Moreover, the lever 4 has on the inner side a plate 4A which closes off a hollow body 4B which acts as a guide for the pin 5, and a compression spring 8 is arranged between the plate 4A and the head of the pin 5 so as to push the latter in abutment against an end stop 4C which prevents the pin 5 from coming out of the hollow body 4B when the mechanism is disengaged from the base 3. As can be seen from the drawings, the base 3 is a hollow base. Namely, the base defines a receiving seat and has an inner wall.
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In the light of the above description, the simple and effective operation of the present mechanism may be readily understood. Starting in the assembly/disassembly position shown in Figures 1-3, the lever 4 is pushed against the base 3 inserting the shaped end 6 inside the corresponding shaped hole 3A until the visor 2 is positioned abutting against the base 3. The pin 5 is then pushed inside the hollow body 4B overcoming the resistance of the spring 8 so that the shaped end 6 is spaced from the inner wall 3 and may rotate freely without sliding contact (Fig.3).
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Operating the end of the lever 4 and keeping the pressure on the pin 5, a rotation through about 90° is performed in an anti-clockwise direction viewed from the outside for the left-hand side (in a clockwise direction, for the right-hand side), until the shaped end 6 is arranged inside an internal seat 3B where it is locked by releasing the pressure on the pin 5, such that the spring 8 brings the end 6 into abutment against the seat 3B (Figs. 5-6). In this way, the walls of the seat 3B prevent the rotation of the pin 5 during use, ensuring the solidity of the attachment of the visor 2.
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Preferably, therefore, the seat 3B is configured to prevent the rotation of the pin 5, namely prevent the pin 5 from being accidentally released from the seat 3B when there is no pressure acting on the pin 5, i.e. when the head of the pin 5 is abutting against the end stop 4C.
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Obviously, release is performed with the reverse sequence of operations: applying pressure on the pin 5 so as to disengage the shaped end 6 from the seat 3B, rotating the lever 4 through about 90° in a clockwise direction while keeping the pressure applied on the pin 5 until the shaped end 6B comes into alignment with the shaped hole 3A, releasing the pressure on the pin 5 and extracting it from the base 3.
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Namely, the pin 5 is preferably configured to be able to slide axially with respect to the actuating lever 4, i.e. inside the hollow body 4B of the lever 4, against the action of the spring 8 which, when no pressure is applied by the user, keeps the head of the pin 5 in abutment against the end stop 4C.
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The pin 5 is also preferably configured to be able to rotate integrally with the lever 4 about its axis, in such a way that a pressure on the pin 5 favours the sliding thereof inside the chamber 4B and therefore the insertion of the shaped end 6, fixed onto the end part of the pin 5, through the shaped hole 3A, and a subsequent rotation of the lever 4, and therefore a rotation of the pin 5, allows the shaped end 6 to be positioned inside the seat 3B; in particular, preferably, the consequent release of the pressure on the pin 5 allows the shaped end 6 to be housed inside the seat 3B.
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It is clear that the embodiment of the mechanism according to the invention described and illustrated above constitutes only one example which may have numerous variants. In particular, the elastic element could be made differently from the spring 8 mounted on the pin 5, for example it may be an alternative elastic element, and the connection between the element 6 and the pin 5 could be obtained using means different from the screw 7 (e.g. by means of gluing or heat welding).
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Similarly, the hole 3A must not necessarily have the same form and size as the shaped end 6 since it is sufficient for it to allow the end to pass through and then engage inside the seat 3B. Moreover, the rotational constraint between the lever 4 and the pin 5 may be realized in any known manner, the simplest and most general way being to provide a non-circular cross-section of the pin 5 and of the associated hollow body 4B inside which it slides axially.
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Finally, in order to make the assembly/disassembly operation even easier, the mechanism could have a further element which interacts with the pin 5 so as to realize a push-push type operation, namely with the pin 5 which, once pressed, remains in a retracted position relative to the lever 4 until it is pressed again. This enables the attachment and release movement to be performed with a single hand and/or more easily since it is not required to keep pressure applied onto the pin 5 during rotation of the lever 4.