ROLLER SKI COMPRISING AN IMPROVED SHOCK ABSORBER DEVICE

Abstract

The present invention is related to a roller ski with an adapted shock absorber device arrangeable inside a hollow backend of the roller ski body (16), wherein a first member (11) of the shock absorber device is supporting a backend wheel of the roller ski, a second member (14) is attachable to an inside surface of the hollow backend of the roller ski body (16), wherein a material strip (13) of a stretchable and compressible material is arranged in between the first and second member (11, 14).

Description

FIELD OF THE INVENTION

The present invention relates to a roller ski comprising an improved shock absorber device providing improved stability of roller skis.

BACKGROUND OF THE INVENTION

Roller skis is a popular form of skis used on dry land in summertime and is used both for amateurs as well as competing athletes doing cross-country skiing. It is evident that the experience of using roller skis on dry land compared to using real skis on snow is a different experience. However, if you want to train and improve your skills on skis also in summer on dry land the roller skis may be used if they to some extent can emulate the feeling of running on snow. Roller skis are normally used on hard road surfaces which are reflected in the legs of a skier on the roller skis. This may be different from running on snow which normally are softer than asphalt for example. Other differences between snow and hard road surfaces experienced by skiers may be dependent on the ski technique that is used. Diagonal stride skiing is different from skating techniques.

One example of a difference between skating and diagonal stride is the presence of ski tracks or not. Cross country skiing can be done freely on un-prepared snow or in prepared snow tracks while ski skating almost always requires prepared even surfaces.

Emulating the feeling of using real skis on real snowy surfaces with roller skis on hard surfaces is usually made by adapting a shock absorber device or similar devices or systems arranged between respective wheels of roller skis and the body of the roller skis.

WO 2019017802 A1 disclose a roller ski shock absorber designed to eliminate vibrations arising during the rolling of the roller ski along asphalt surface and create a snow feel featured by snow ski. The roller ski shock absorber consist of the wheel carrier (1) and the shock absorber carrier (3) bound together by rubber stripe (2) in the process of rubber vulcanization while the shock absorber carrier is fixedly attached to the roller ski body end (4) while the wheel axle (6) with the wheel (5) is fixedly attached to the protruding end of the wheel carrier (1). Variant 2 features the roller ski body (4) and the wheel carrier (1) bound together by rubber stripe thereby eliminating the use of the shock absorber carrier (3). Rubber stripe (2) is vulcanized to both roller ski body and wheel carrier. The roller ski shock absorber is capable to rotate a round its center of rotation (7) as skier's body weight goes on and of the ski.

US20080030014 A1 disclose an apparatus supporting “dry land” simulation of the diagonal stride cross-country skiing technique. The apparatus may include a roller ski comprising at least two wheels configured to roll on a surface and a stop connected to the roller ski. The stop may selectively engage at least one of the surface and the at least two wheels in response to a force of at least a threshold magnitude urging the roller ski toward the surface to resist rearward roll of the roller ski on the surface. The resistance to rearward roll may vary with the force.

NO 20200078 disclose a roller ski shock absorber comprising a wheel carrier (1) and a shock absorber carrier (3) bound together by a rubber strip (2) during vulcanization of the rubber strip. The shock absorber carrier is attached to a roller ski end (4) of the body of the roller ski and the wheel carrier (1) is protruding out from the roller ski end (4) holding a wheel via an adapted wheel axel (6). The roller ski shock absorber is capable of rotating around a centre of rotation (7) arranged at a distance from the backend of the roller ski being ⅔ of the rubber strip (2) length. The wheel carrier is extending outside the backend of the roller ski end (4) with a distance that is larger than the radius of the wheel so that the wheel can spin without interfering with the roller ski (4).

This implies that the wheel carrier between the centre of the wheel and the centre of rotation is relatively long. Any forces acting on the wheel provides a momentum on the centre of rotation (7) being the acting force multiplied with this length.

According to NO 20200078 some parts of the vulcanized rubber strip (2) will be stretched while other parts will be compressed when rotating around the centre of rotation (7) since the shock absorber carrier (3) is fixed to the roller ski body end (4) while the wheel carrier (1) is forced up or down by the wheel carried by the wheel carrier when the wheel passes uneven surface parts the roller ski is running across. NO 20200078 disclose further that stretching of the rubber strip (2) is the main action of the shock absorber.

Roller ski movements relative to a road surface is a composite movement and not just a simple movement. For example, if the skier is exercising diagonal stride on the roller skis the skier lifts one ski at a time and uses one ski at the time to provide movement forward as known in prior art. Therefore, a shock absorber device or system should be able to soften the impact on the roller ski due to the shifting weight impact from the skier when moving forward. When kicking off forward the skier pushes the ski further down towards the ground wherein the direction of the kick is preferably in a direction moving the ski forward.

On real snow the friction between a ski and the snow enables the directional kick. On a roller ski it is normal to have ball bearings in the centre of the backend wheel of a roller ski that is constrained to only rotate in one direction. Therefore, it is common that a roller ski usually cannot roll backwards.

When a skier is kicking off as discussed above the roller ski can be pushed backwards a very short distance which is then stopped immediately by the constrained ball bearings of the backend wheel. However, the stop can be hard if the skier is a strong skier. Therefore, a shock absorber device or system should be able to soften the abrupt impact of a kick-off by a skier thereby emulating how it feels when kicking off on real snow in a ski track.

Therefore, forces acting on a roller ski is impacting the interface between a human foot and an upper roller ski surface in different directions and is usually a consequence of differently but simultaneously acting forces.

The same situation of acting forces on an interface between a human foot and the roller ski is present when a skier is practising skating technique.

Therefore, there is a need of an improved shock absorber device arrangeable in roller skis.

OBJECT OF THE INVENTION

It is an object of the present invention to provide an alternative to the prior art.

In particular, it may be seen as an object of the present invention to provide a shock absorber device enabling improved emulation of snow like conditions when using roller skis.

SUMMARY OF THE INVENTION

Thus, the above-described object and several other objects are intended to be obtained in a first aspect of the invention by providing a shock absorber device arranged inside a hollow end part of a roller ski body, wherein a roller ski wheel is attachable to the shock absorber device.

The invention is particularly, but not exclusively, advantageous for obtaining a roller ski arranged with a shock absorber device, wherein the shock absorber device comprises at least one arm comprising:

• • a first member arranged with a through-hole in one end of the first member arranged to support an axel of a roller ski wheel,
  • a second member attachable to an inner wall of a hollow backend part of a roller ski body,
  • a stretchable and compressive material strip arranged in between surfaces of the first and second member,
  • a surface of the material strip facing towards a surface of the first member is partly covering the surface of the first member leaving an un-covered surface running parallel to a longitudinal direction of the first member on both sides of the surface of the first member.

Respective aspects of the present invention may each be combined with any of the other aspects. These and other aspects of the invention will be disclosed and elucidated with reference to the embodiments described herein.

DESCRIPTION OF THE FIGURES

FIG. 1 illustrates an example of embodiment of the present invention.

FIG. 2 illustrate the example of embodiment illustrated in FIG. 1 as viewed from a different angle.

FIG. 3 illustrate the example of embodiment illustrated in FIG. 2 as viewed from a different angle.

FIG. 4 illustrates the example of embodiment illustrated in FIG. 2 as viewed from a different angle.

FIG. 5 illustrates an example of embodiment of the present invention mounted onto a roller ski.

DETAILED DESCRIPTION OF AN EMBODIMENT

Although the present invention is disclosed in connection with specific examples of embodiments, it should not be construed as being in any way limited to the presented examples. The accompanying claim set defines the scope of protection of the present invention. In the context of the claims, the terms “comprising” or “comprises” do not exclude other possible elements or steps. Further, the mentioning of references such as “a” or “an” etc. should not be construed as excluding a plurality. The use of reference signs in the claims with respect to elements indicated in the figures shall also not be construed as limiting the scope of the invention.

Furthermore, combining individual features mentioned in different claims may possibly be advantageously, and the mentioning of these features in different claims does not exclude a combination of features is not possible and advantageous.

FIG. 1 illustrates an arm 10 of a shock absorber device according to the present invention. The arm 10 comprises a first member 11 arranged with a through hole 12 adapted to support an axel holding a backend wheel of a roller ski. A second member 14 is arranged on an opposite side of the first member 11. In between the first and second members 11, 14 there is arranged a material strip 13 of a stretchable and compressible material, for example vulcanized rubber which can be made of natural rubber or any other synthetic material, for example based on polymer compositions etc. The material strip 13 is covering a whole surface of the second member 14 while a surface of the first member 11 facing towards the material strip 13 has a free uncovered section 13a running along the longitudinal direction of the first member 11.

The first and second members 11, 14 may be embodied using metal plates or for example composite materials providing lightweight members etc.

FIG. 2 illustrates the same arm 10 of a shock absorber according to the present invention illustrated in FIG. 1 when viewed towards a front side surface of the second member 14. Along a centred line parallel with the longitudinal direction of the second member 14 there is arranged a set of threaded holes 15 adapted to receive attachment bolts or screws when a shock absorber device according to the present invention is attached to a roller ski body. At least two holes 15 are arranged. More details are provided below.

FIG. 3 disclose the same arm 10 as illustrated in FIG. 2 when viewed directly towards the surfaces of the second member 14.

FIG. 4 disclose the same arm 10 as illustrated in FIG. 2 when viewed towards an end of the first member 11 comprising the hole 12 supporting an axel supporting a wheel attached to the arm 10. As illustrated the hole 12 supporting an axel of a wheel is arranged with an offset relative to a centred line running in the longitudinal direction of the first member 11.

FIG. 5 illustrates a section of a backend of a roller ski body 16 of an example of embodiment of the present invention comprising a cut-out 16a adapted to fit a wheel supported by arms 10 of a shock absorber device of the present invention. The cut out 16a leaves two protruding parts 16b, 16c running in parallel with the longitudinal direction of the roller ski body on each side of the roller ski body 16 providing space for an example of embodiment of a shock absorber device according to the present invention. The protruding part 16c is not illustrated.

FIG. 5 illustrates a first arm 10 according to the present invention fitted inside an inner hollow part of one of the protruding parts defined by the cut-out 16a of the roller ski body 16. The first arm 10 is attached via bolt or screws inserted through a side surface of the roller ski body 16 facing towards the second member 14, wherein the respective bolts are inserted and fastened in the respective threaded holes 15 arranged on the surface of the second member 14 facing the inside wall of the hollow interior of the roller ski body 16. The bolts or screws fastened in the respective holes 15 of the second member is not passing through the body of the second member 14. The bolts or screws are adapted in length to the thickness of the second member 14.

The material strip 13 is arranged on a surface of the second member 14 facing inwards into the hollow interior of the roller ski body 16. The first member 11 is then arranged on an outside surface of the material strip 13 facing inwards into the hollow interior of the body 16 of the roller ski.

A second arm 10 according to the present invention is also located inside the hollow interior of the backend of the roller ski body 16. The second arm is located opposite the first arm and the elongated length of the first and second arm is running parallel with the longitudinal direction of the roller ski body 16. However, the first arm and the second arm are a mirrored version of each other.

The respective different members 11, 13 and 14 of a shock absorber device of an example of the present invention can be assembled before inserted into the hollow interior of the roller ski body 16. For example, a strip of the material strip 13 can be arranged in a form together with the respective members 11 and 14 on each side and then heated and vulcanized as known in prior art.

An aspect of the design of the shock absorber device according to the present invention is that the material strip 13 may be of a size such that a bottom edge and a respective top edge running in parallel with the body 16 of the roller ski is in contact with a respective inner bottom and a respective inner roof of the hollow interior of the body 16 of the roller ski, i.e., for example inside the protruding parts left on each side of the cut-out 16a.

The side of the material strip 13 has a side surface facing towards the member 11 and the side surface of the material strip is arranged with a non-covered section 13a as illustrated in FIG. 1.

In this manner the material the strip 13 is to some extent constrained in upper and lower edges of the body in a longitudinal direction of the material strip 13 as discussed above while a surface, part i.e., the surface part 13a is un-covered and is in operational contact with the first member 11 supporting the wheel.

This arrangement of the respective members of a shock absorber according to the present invention is stabilized inside a hollow part of a back end of a roller ski and at the same time is arranged to absorb mechanical impact in an interface area between a human leg and forces acting on a roller ski body from any direction.

The shock absorber effect, i.e., how hard, or soft the absorbing is done is primarily a function of the material composition of the material strip 13. These properties can be adjusted as known in prior art.

According to an example of embodiment of the present invention a roller ski is arrangeable with a shock absorber device, wherein the shock absorber device may comprise at least one arm 10 comprising:

• • a first member 11 arranged with a through-hole 12 in one end of the first member 11 arranged to support an axel of a roller ski wheel,
  • a second member 14 attachable to an inner wall of a hollow backend part of a roller ski body 16,
  • a stretchable and compressible material strip 13 arranged in between surfaces of the first and second member 11, 14,
  • a surface of the material strip 13 facing towards a surface of the first member 11 is partly covering the surface of the first member 11 leaving an un-covered surface 13a running parallel to a longitudinal direction of the first member 11 on both sides of the surface of the first member 11.

According to the example of embodiment disclosed above, a cut-out 16a may be arranged in a backend part of the roller ski body 16.

According to the example of embodiment disclosed above, the cut-out may leave two protruding parts 16b, 16c on each side of the cut-out 16a running in a direction of the longitudinal direction of the roller ski body 16.

According to the example of embodiment disclosed above, the cut-out 16a may be dimensioned to support a roller ski wheel.

According to the example of embodiment disclosed above, a respective one of the arms 10 is arranged inside each protruding parts 16b, 16c, wherein one of the two shock absorber arms 10 is a mirrored version of the other one.

According to the example of embodiment disclosed above, a specific material property of the material strip 13 is defined by the material composition controlling a softness property of the material strip 13.

According to the example of embodiment disclosed above, the material strip 13 of the respective arms 10 are dimensioned such that an upper side edge and a lower side edge of the material strip 13 is in contact with a top and respective bottom surface of the respective protruding cut-out parts 16b, 16c.

According to the example of embodiment disclosed above, the uncovered surface 13a of the first member 11 is running in parallel with the longitudinal direction of the first member 11 on only one side of the first member 11.

According to the example of embodiment disclosed above, the second member 14 is attachable to the inner wall of the hollow backend of the roller ski body 16 with bolts or screws adapted to fit into at least two threaded holes 15 on a side surface of the second member 15.

According to the example of embodiment disclosed above, a length of the respective bolts or screws are adapted in length to a thickness of the second member 14.

Claims

1. A roller ski arranged with a shock absorber device, the shock absorber device comprises: at least one an arm including: a first member arranged with a through-hole in one end of the first member arranged to support an axel of a roller ski wheel;a second member attachable to an inner wall of a hollow backend part of a roller ski body;a stretchable and compressive material strip arranged in between surfaces of the first and second member; anda surface of the material strip facing towards a surface of the first member is partly covering the surface of the first member leaving an uncovered surface running parallel to a longitudinal direction of the first member on both sides of the surface of the first member.

2. The roller ski of claim 1, wherein a cut-out is arranged in a backend part of the roller ski body.

3. The roller ski of claim 2, wherein the cut-out leaves two protruding parts on each side of the cut-out running in a direction of the longitudinal direction of the roller ski body.

4. The roller ski of claim 2, wherein the cut-out is dimensioned to support a roller ski wheel.

5. The roller ski of claim 3, wherein a respective one of the arm is arranged inside each protruding parts, wherein one of the two shock absorber arms is a mirrored version of the other one.

6. The roller ski of claim 1, wherein a specific material property of the material strip is defined by the material composition controlling a softness property of the material of the material strip.

7. The roller ski of claim 5, wherein the material strip of the respective arms are dimensioned such that an upper side edge and a lower side edge of the material strip is in contact with a top and respective bottom surface of the respective protruding cut-out parts.

8. The roller ski of claim 1, wherein the uncovered surface of the first member is running in parallel with the longitudinal direction of the first member on only one side of the first member.

9. The roller ski of claim 1, wherein the second member is attachable to the inner wall of the hollow backend of the roller ski body with bolts or screws adapted to fit into at least two threaded holes on a side surface of the second member.

10. The roller ski of claim 9, wherein a length of the respective bolts or screws are adapted in length to a thickness of the second member.