"ROLLER SKI"

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FIELD OF THE INVENTION

The present invention concerns a roller ski, used to practice a sporting activity known in English as "roller skiing", in which, during the warm seasons, an athletic movement is simulated which is substantially the same as that practiced in cross-country skiing, or similar sporting activity. BACKGROUND OF THE INVENTION

Roller skis are known, substantially consisting of a metal profile, for example aluminum, steel or other, on the upper surface of which an attachment is provided, to constrain the athlete's foot. At the ends of the metal profile respective sliding rollers are pivoted, for example one roller at the front end of the tubular body and one or more rollers, adjacent to each other, at the rear end of the tubular body.

Solutions are also known for roller skis in which the rollers are mounted in line along the whole length of the metal profile.

This type of known ski, since it is made wholly of metal, has the disadvantage that it does not absorb the vibrations that are generated when the sporting activity is practiced: on the contrary, it transmits them almost entirely to the athlete.

This disadvantage can cause premature fatigue or muscular soreness for the athlete and in the long term can cause slight damage to the joints of the legs and back. Known skis made of metal also have relatively high production costs, and their size and aesthetic form are substantially limited by the size and aesthetic form of the metal part of which they are made.

Roller skis are also known, made with a plurality of layers of wood, or wood substitutes, held associated with each other by resins or other adhesive materials.

The resistance to stress of this second type of known ski is much lower than that of known metal skis, and they are more subject to breakage and malfunctions. To compensate for this lack of resistance, it is known to increase the number of layers of wood that make up this type of known ski, or to make reinforcements or stiffening ribs on them. However, in practice, this solution is detrimental to the lightness of the structure, consequently causing an excessive fatigue for the athlete when he/she is practicing the sport.

One purpose of the present invention is therefore to make a roller ski which, while guaranteeing normal conditions of strength and resistance to stresses, absorbs the vibrations imparted by the ground during the sporting activity, and which does not need thicker parts or ribs on its structure. Another purpose of the present invention is to make a roller ski that is simple and economical to produce.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages. SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea. In accordance with the above purposes, a roller ski according to the present invention comprises at least a main or bearing structure, made of metal material and with which the rollers are rotatably associated, and a secondary

or cohesion structure, made of non-metal material and able to at least partly cover the main structure, so as to absorb possible vibration stresses.

In this way, the combination of the main metal structure and the secondary structure of non-metal material allows a greater absorption of the vibrations and stresses imparted by the ground to the ski, when the sporting activity is practiced, and hence without affecting the athlete's muscular resistance. Moreover, since the ski is made partly of metal material and partly of non-metal material, this guarantees mechanical resistance to stresses on the one hand, and on the other hand guarantees the lightness of the ski, and hence reduces the efforts necessary for the user both during the sporting activity and also when the ski is transported.

Advantageously, the main structure comprises two lateral foils, for example made of aluminum, preferably thin and connected to each other by the secondary structure, so that the latter represents the substantive part of the overall structure of the ski according to the invention.

This advantageous solution allows to shape and personalize the design of the ski, since its external profile is defined only by the secondary structure made of non-metal material, which can easily be made as desired according to the known techniques of molding or forming.

The non-metal material of the secondary structure, according to some preferential forms of embodiment of the present invention, can consist for example of injected thermoplastic resins, or a structure formed by so-called "skins" made of carbon fiber, fiberglass or other composite material.

Advantageously, the rollers comprise a hub pivoted to one

end of the main metal structure, around which a circumferential covering made of plastic or elastomer material, or other material resistant to abrasions, is disposed. The hub substantially consists of two specular disks, coupled coaxially with each other with respect to the axis of rotation of the relative roller.

This solution allows to selectively separate the two disks, making the replacement of the rollers or the circumferential covering alone simpler and quicker. BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some preferential forms of embodiment, given as non-restrictive examples with reference to the attached drawings wherein: - fig. 1 is a three-dimensional view from above of a first form of embodiment of a roller ski according to the present invention;

- fig. 2 is a three-dimensional view from below of the roller ski according to the present invention; - fig. 3 is a three-dimensional view of a component of the roller ski in fig. 1;

- fig. 4 is an enlarged detail, partly in section, of a component of the roller ski in fig. 1;

- fig. 5 is a second form of embodiment of the roller ski in fig. 1;

- fig. 6 is a third form of embodiment of the roller ski in fig. 1. DETAILED DESCRIPTION OF SOME PREFERENTIAL FORMS OF

EMBODIMENT With reference^ to figs. 1 and 2, a roller ski 10 is shown in its entirety.

In general, the ski 10 substantially consists of a metal bearing part 11, and a non-metal cohesion part 12, which

incorporates a substantive segment of the metal part 11, so as to define a structure having characteristics of great lightness, strength and resistance to stresses.

The ski 10 also comprises a first front roller 13 and a pair of rear rollers 15 mounted rotatable on respective ends of the structure defined by the combined metal part 11 and non-metal part 12.

In this case, the metal part 11 consists of two lateral flanks 16 (fig. 3) distanced from each other, made of aluminum and shaped as a foil.

At the front the two lateral flanks 16 define a fork 17, with respect to which the front roller 13 is rotatably mounted, and at the rear a pivoting block 19 on which the two rollers of the above pair of rear rollers 15 are mounted, on opposite sides.

The non-metal part 12 in this case is made by a preformed structure by means of injection into a mold of thermoplastic resins, possibly charged with carbon fiber, fiberglass or other, and defines the substantive part and also the design of the ski 10.

In an alternative solution, the non-metal part 12 is made by means of layers, or "skins" of composite material such as carbon fiber, fiberglass or other.

The non-metal part 12 incorporates the two lateral flanks 16 so as to leave both the fork 17 and the pivoting block 19 outside (figs. 1 and 2).

The non-metal part 12 comprises an upper surface 20 substantially plane and suitable to attach bindings so as to constrain the athlete's foot to the ski 10, and a lower surface 24 conformed as a lattice-work, to give the ski 10 good mechanical resistance and at the same time a relatively low weight.

The structure thus consisting of the lateral flanks 16

partly incorporated into the non-metal part 12 is able to absorb the vibrations transmitted by the ground during the sporting activity, preventing them from affecting the athlete. This advantage considerably reduces for the athlete the muscular soreness due to these vibrations.

It is clear that, depending on the different uses of the ski 10 and/or the build of the users and/or the ground which is used, or other, both the lateral flanks 16 and the non-metal part 12 can be reinforced as desired with so- called carbon "skins", or other, so as to guarantee optimum conditions of use and the longest possible duration of the ski 10.

In this case, the non-metal part 12 also comprises, in correspondence with the front rollers 13 and rear rollers 15, respective spray guards 21, made in a single piece, which surround the rollers 13 and 15 for an upper segment thereof; the spray guards 21 prevent water, soil or other from accidentally reaching the foot or lower part of the leg of the athlete while he/she is practicing the sporting activity.

The front 13 and rear 15 rollers, in the embodiments shown in the drawings, are substantially identical and comprise a hub 22 (fig. 4) associated externally with a circumferential covering 23 made of plastic material or elastomer resistant to abrasions.

In particular, the hub 22 is made as two specular disks 22a and 22b, coupled axially with each other with respect to the axis of rotation of the roller 13 or 15. The coupling of the two disks 22a and 22b occurs by means of a plurality of attachment elements 26 distributed angularly on both disks 22a and 22b. The attachment elements 26 are of a substantially known type and will not

be described in detail here, and can consist of hardware elements, such as screws, nuts or other, or pressure or elastic fitting members or other.

In this way, operations to replace the rollers 13, 15, are considerably facilitated and, unlike in the state of the art, it is possible to replace only the circumferential covering 23, without having to replace the whole roller 13, 15. In fact, by reciprocally separating the two disks 22a and 22b, the circumferential covering 23 is released from the hub 22.

In the embodiment shown in fig. 5, the metal part 11 of the ski 10 consists of two lateral flanks 116 substantially parallel and able to define both at the front and at the rear respective forks 117 for the rotatable assembly of a respective front roller 13 and a respective rear roller 15.

In this embodiment, the non-metal part 12 is made by injecting thermoplastic resins and is substantially identical to the non-metal part 12 of the embodiment shown in figs. 1 and 2, with the difference that it comprises at the rear only one spray guard 21, only for the rear roller

15 provided.

In the embodiment shown in fig. 6, the ski 10 consists of a metal part 11 formed substantially by two lateral flanks 216, substantially parallel and shaped reciprocally so as to define a central bulge in the structure, and a non-metal part 12, substantially box-shaped, which incorporates the two lateral flanks 216 in correspondence with the bulge defined thereby.

In this case, the non-metal part 12 is made with a structure formed by layers of carbon fiber, and the two lateral flanks 216 are connected and held distant not only by the non-metal part 12, but also by a plurality of transverse blocks 25, of which only two are shown. The

transverse blocks 25 have both the function of stiffening the structure of the ski 10, and also the function of keeping the reciprocal shaping of the two lateral flanks 216. It is clear, however, that modifications and/or additions of parts may be made to the ski 10 as described heretofore, without departing from the field and scope of the present invention.

For example, it comes within the field of the present invention to provide that the lateral flanks 16, 116, 216 of the metal part 11 can be shaped as a reticular lattice, or an open profile, for example as a T, H, C or other, covered externally, partly or completely, by the non-metal part 12. It also comes within the field of the present invention to provide that the rear rollers 15 have a greater diameter than the front rollers 13, and/or that the tread of the first is narrower than that of the second.

According to another variant, the non-metal part 12, 112 can provide, made directly on the upper surface 20, bindings for the athlete's foot.

It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of roller ski, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.