Skis, especially cross-country skis

Abstract

The invention relates to a ski (1), in particular a cross-country ski, with a shaping base body (2) and a sliding surface (5) arranged on the underside of the base body (2), which extends in the longitudinal direction (8) and width direction (9) of the ski, wherein, with respect to the longitudinal direction (8), at least one recess (7) is formed between a front and a rear sliding section (31, 32) in the kick zone (12), which is provided for receiving at least one anti-slip climbing or kicking aid (21). The at least one recess (7) extends continuously over the entire width (6) of the sliding surface (5) of the ski (1). The depth (15) of the at least one recess (7) decreases from at least one of the longitudinal edges (33) of the ski (1) in the width direction (9) towards the center of the ski (1).

Description

The invention relates to a ski, in particular a cross-country ski, with a sliding surface arranged on the underside of the base body, on which a recess extending over its entire width is arranged for receiving a back-slip-inhibiting climbing or pushing aid. Skis with recesses or grooves for climbing or pushing aids that can be inserted therein are known from the prior art. From WO2016118999 A1, the arrangement of anti-slip elements in staggered groove-shaped recesses is known, wherein the ends of the groove-shaped recess are spaced apart along the longitudinal direction of the ski. This arrangement is intended to result in a particularly smooth transition between the gliding and climbing phases. Furthermore, a detachable connection using a hook-and-loop fastener or an adhesive layer is proposed to allow for easy replacement of the anti-slip element for individual adaptation to different applications. A replaceable climbing or push-off aid is also disclosed in AT519764 B1. It describes a method for user-specific adaptation of a ski using at least one climbing aid and base insert, which can be inserted into and removed from a recess. An advantage of this ski design is that the anti-slip climbing or push-off aid can be adapted to the user's weight or size and their skiing style. Thus, a standard ski with a standard recess can be individually adapted to a single user. / 28 N2019 / 33700-AT-00 The prior art embodiments provided only partially satisfactory solutions for adapting the gliding and rebounding behavior of the ski to the individual wishes or requirements of the respective users. The object of the present invention was to overcome the disadvantages of the prior art and to provide a ski whose gliding and rebound behavior can be adapted as well as possible to the individual needs of the user using the simplest possible technical means and offers more design freedom. This task is solved by a ski that meets the requirements. The ski according to the invention, in particular a cross-country ski, comprises a shaping base body and a gliding surface arranged on the underside of the base body. The gliding surface extends in the longitudinal and lateral directions of the ski, has a front and a rear gliding section with respect to the longitudinal direction, and between the front and rear gliding sections, in the kick zone, there is at least one recess which extends continuously over the entire width of the gliding surface, in which at least one recess can be arranged and arbitrarily positioned to prevent backslip. Accordingly, the at least one recess or depression in the gliding surface extends uninterrupted between the opposing side surfaces or side walls of the ski's base body. For the sake of simplicity, the anti-slip element or anti-slip climbing or push-off aid will henceforth be referred to simply as the push-off aid. The push-off zone is located at least predominantly or entirely in the middle third with respect to the longitudinal direction of a ski and extends over a range of between 20% and 50% of the ski's length, preferably between 30% and 40% of the ski's length. / 28 N2019 / 33700-AT-00 An advantage of the ski design according to the invention is that the recess allows for additional placement options in the longitudinal and lateral directions for push-off aids. A further advantage of the design according to the invention is that the This cutout can lead to additional weight savings in a ski, which is a crucial criterion, especially in cross-country skiing. It has also proven advantageous that the ski according to the invention is also better suited for users who suffer from knee misalignments or misalignments of the foot or hip, in whom these misalignments cause pushing off primarily on the outside or inside of the ski. A ski according to the invention is also particularly suitable for cross-country skiers who prefer a climbing or pushing-off technique using the outer or inner edge of the ski. An example of this would be the so-called skating technique. In an advantageous embodiment, the total area, in particular the projected base area, of the at least one recess is larger than the anti-slip effective area of ​​the at least one push-off aid, so that the push-off aid can be positioned freely in the recess in the longitudinal and / or transverse direction. This makes it easy to improve or more comprehensively adapt the push-off or gliding behavior of the ski to the individual needs of the user, their skiing style, or the prevailing ground conditions, such as soft snow, hard snow, or icy conditions. According to an advantageous embodiment, the length of the recess is greater than the greatest length of the push-off aid, i.e., the length from the front to the rear end of the push-off aid, with respect to the longitudinal direction of the ski. This allows material for the push-off aid to be saved, and only the actually required length can be used. This results in an optimum of variability, usable push-off area, and cost-effectiveness. It has been found that it is suitable for / 28 N2019 / 33700-AT-00 is moderate if the greatest length of the repulsion aid is 30 to 95% of the length of the recess, preferably 40 to 90%, particularly preferably 50 to 80%, and especially 60 to 70% of the length of the recess. According to an advantageous embodiment, the width of the recess is greater than the maximum width of the push-off aid with respect to the width direction of the ski. This also leads to material savings. Furthermore, this allows the actual required width of the push-off aid to be determined depending on the ski's inclination during skiing. It has proven advantageous if the maximum width of the push-off aid is 10 to 95%, preferably 20 to 90%, particularly preferably 30 to 75%, and especially 40 to 55%, of the recess width. Thus, the length and width of the push-off aid can be selected by the user and / or by the ski manufacturer within relatively wide ranges. Furthermore, it can be advantageous if the longitudinally forward transition area between the recess and the sliding surface of the sliding lining is stepped, in particular with sharp edges. The resulting shape can, on the one hand, secure a push-off aid inserted into the recess against unwanted detachment and, on the other hand, form an additional anti-slip element. Furthermore, the rear transition area between the recess and the sliding surface of the sliding lining may be longitudinally flattened or ramped to ensure an optimal transition between the push-off aid and the sliding surface. This design can also facilitate the removal of unwanted debris from the recess. Furthermore, it can be advantageous if the base surface of the recess has a wavy or sawtooth contour in the longitudinal section. 5 / 28 N2019 / 33700-AT-00 indicates that a push-off aid can be partially offset in the depth direction of the recess. This design serves to further improve the push-off behavior. According to a particularly advantageous embodiment, the depth of the recess can decrease from at least one of the ski's longitudinal edges towards the center of the ski. This allows the effective surface area of ​​the push-off aid to be optimally utilized when shifting the skier's weight to the outer or inner edge. An example of this is the so-called "skating" technique. This allows the push-off aid to be optimally aligned with the surface. Similarly, the transition area between the recess and the gliding surface can have a decreasing depth in the lateral direction to ensure a smooth transition. Preferably, the push-off aid is positioned in the recess using a detachable fastener, allowing it to be removed and repositioned as needed. This design offers, among other things, easy replacement when the push-off aid becomes worn. Furthermore, this is advantageous, for example, when the terrain changes, the skiing style changes, or the ski is used by a different skier. Furthermore, it can be advantageous to select a fastening material from the group consisting of pressure-sensitive adhesives, adhesive nanostructures based on the so-called gecko effect, hook-and-loop fasteners, magnetic adhesives, or electrostatic adhesives. These offer a cost-effective and readily available fastening option. Moreover, they also facilitate improved adaptability to individual user requirements. An additional advantage is that a strap can be attached to the ski-side recess as a fastening means for the push-off aid. This strap encircles a cross-sectional circumference of the ski in the area of ​​the recess and can be moved longitudinally and relative to the ski's cross-sectional circumference as needed. This allows for a particularly simple and quick way to... / 28 N2019 / 33700-AT-00 to reposition the push-off aid in the recess in the longitudinal and lateral direction and, if necessary, to temporarily remove it completely from the recess by further shifting it around the cross-sectional circumference. The design of the push-off aid is freely selectable and can consist of various materials known from the prior art. These can include, for example, a climbing skin with synthetic or natural fibers, a rubber coating, a waxed band, a plastic coating with a slip-resistant surface profile, such as scales or a sawtooth structure, combinations thereof, and other embodiments. The use of a flexible, textile-like climbing skin as a push-off aid has proven particularly advantageous, as its length and width can be easily adjusted by the user afterward, for example, by simply cutting it to size. Furthermore, the shape of the push-off aid is freely selectable by the user and can, for example, be curved or V-shaped. Furthermore, the recess can be designed with several push-off aids positioned at will, which can also vary in size or surface area. These can, for example, be arranged one behind the other lengthwise and offset widthwise, or side by side widthwise and offset lengthwise. There are virtually no limits to the design possibilities here. The recess itself can be a cutout, meaning the gliding layer is at least partially removed in the area of ​​the recess, so that the base of the recess, i.e., the area facing the ski core, is formed from the underlying layer, e.g., an ABS plastic. Alternatively, the base of the recess can be formed by some kind of embossing, pressing, or simply a depression in the base body and thus consist of or be limited by the gliding layer itself. / 28 N2019 / 33700-AT-00 In some applications, it may also be intended that the length and / or width of the push-off aid corresponds entirely to the recess and can thus cover it completely. For the sake of completeness, it should be mentioned that a ski of this type generally does not have independent metal guide or limiting edges, and in particular does not form so-called steel edges, which is especially typical for cross-country skis. If a ski were to be designed with metal lateral guide or limiting edges, these edges would have to be interrupted or deepened in their partial or longitudinal section by the recess, so that the recess or depression in the gliding base, which is intended to accommodate at least one push-off aid, can extend continuously across the entire width of the ski's gliding base. To better understand the invention, it is explained in more detail with reference to the following figures. They each show, in a highly simplified, schematic representation: Fig. 1 shows a ski, in particular a cross-country ski, in side view with a recess within the kick zone; Fig. 2 shows a ski according to Fig. 1 in a view from below; Fig. 3 shows an embodiment of the rear transition area in the longitudinal direction between a recess and the sliding surface; Fig. 4 shows an embodiment of the front transition area in the longitudinal direction between a recess and the sliding surface; Fig. 5 shows an embodiment of a recess in side view; Fig. 6 shows an embodiment of a recess in cross-section; / 28 N2019 / 33700-AT-00 Fig. 7 shows an enlarged representation of a ski's push-off zone with a possible arrangement of a push-off aid in a recess, viewed from below; Fig. 8 shows another embodiment of a push-off aid with a strap in side view; Fig. 9 shows the embodiment according to Fig. 8 in a view from below; Fig. 10 shows a roughly simplified cross-section of a ski in the area of ​​the recess with a band element surrounding the ski cross-section. It should be noted at the outset that in the differently described embodiments, identical parts are provided with the same reference numerals or component designations, and the disclosures contained in the entire description can be applied analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the figure directly described and illustrated, and these positional designations must be applied analogously to the new position if the position changes. Figures 1 and 2 show a ski 1 in which at least one recess 7 is provided in the push-off zone 12 for receiving at least one anti-slip push-off aid 21. Such a ski belongs to the category of so-called cross-country skis, which are designed for gliding and for easily traversing inclines. The ski shown can also be used as a so-called touring ski. It should be designed as a mountaineering ski. This means that the ski disclosed herein can be designed both as a cross-country ski for groomed or ungroomed terrain, and as a ski for mountaineering. Fig. 1 shows an embodiment of a ski 1 according to the invention, in particular a cross-country ski, which has a defined preload height in the central area, i.e., in the binding mounting section, in a manner known per se. This preload height defines the kick zone 12 of the underside or running surface of the ski. / 28 N2019 / 33700-AT-00 The ski body is spaced 28 degrees from a flat surface in its unloaded state or in load states below a predetermined threshold. This pre-tension height is comparatively greater for cross-country skis than for touring or mountaineering skis. With respect to the longitudinal direction 8, the ski 1 has a front end 10 and a rear end 11, which are essentially defined by the direction of travel during use. It consists of a base body 2, on the underside of which, in the longitudinal direction 8 and the lateral direction 9, a sliding surface 5 is arranged with a front sliding section 31 and a rear sliding section 32. Between these sliding sections 31, 32, in the area of ​​the push-off zone 12 of the base body 2, there is at least one recess 7 on its underside, which is provided for receiving a push-off aid 21. According to the invention, said recess 7 extends continuously, i.e., without interruption, over the entire width 6 of the sliding surface 5. Furthermore, a possible ski binding is shown in a simplified form in the illustrated embodiment. The length 13 of the recess 7 can generally vary; it can extend in both directions from the center of the binding mounting section and usually runs over the entire release zone 12. At both ends, viewed in the longitudinal direction 8, a front transition area 16 and a rear transition area 17 are located between the recess 7 and the sliding surface 18 of the sliding lining 5. These transition areas can be designed differently depending on their purpose. For example, the rear transition area 17 can be flattened or rounded to ensure a particularly smooth transition between a push-off aid 21 in the recess 7 and the sliding surface 18. The front transition area 16 can also be flattened, but preferably it can be stepped between the recess 7 and the sliding surface 18 of the sliding lining 5. / 28 N2019 / 33700-AT-00 The base surface 19 of the recess 7, i.e., the area facing the ski core 3 and forming the end of the recess 7 in the depth direction, can be formed by the underlying layer 4 and / or by the gliding surface 5 itself. The ski core 3 itself is generally made of lightweight material and consists, for example, of a rigid foam, in particular PU foam, but can also comprise other materials such as wood with a honeycomb structure. As is known from the prior art, the ski core 3 is generally enclosed in a shell-like manner by an upper rib 29, also called a cap construction, which is also generally made of lightweight material. The layer located under the gliding surface usually comprises a plastic, in particular acrylonitrile butadiene styrene (ABS), but can also comprise, for example, a glass fiber reinforced plastic. The gliding surface 5 itself can also be made of plastic, preferably polyethylene.Of course, there can be further layers between these layers, such as a spacer layer. Fig. 2 shows a ski 1 according to Fig. 1 from below. It is illustrated that the recess 7 extends over the entire width 6 of the sliding surface 5 or base body 2. Thus, the width 14 of the recess 7 corresponds to the width 6 of the sliding surface 5 or base body 2 in this longitudinal section of the ski 1. The length 13 and width 14 of the recess 7 therefore form a total area 20, which is preferably larger than the maximum length 23 and maximum width 24 and the resulting effective area 22 of an optionally positioned push-off aid 21. The front transition area 16 and the rear transition area 17 are only indicated here as the ends of the recess 7. The base 19 of the recess 7 can also be formed by the underlying layer or by the sliding surface 5. The ski 1 also has a lateral limiting edge or longitudinal edge 33 at both ends in the width direction 9, which forms the outer and inner edges. Figures 3 to 10 show further and possibly independent embodiments of a recess 7 of the ski 1, whereby the same reference numerals or component designations are used for identical parts as in the preceding Figures 1 and 2. To avoid unnecessary repetition / 28 To avoid N2019 / 33700-AT-00, reference is made to the detailed description in the preceding figures and 2. Fig. 3 shows a possible configuration of a longitudinally 8 rear transition area 17 of a recess 7. This area is flattened or ramped from the sliding surface 18 towards the recess 7. This configuration can serve several purposes, such as draining away accumulations of unwanted contaminants and snow from the recess. Furthermore, this configuration can make sliding smoother and prevent resistance against the direction of travel. In addition, in the embodiment shown here, the recess 7 is formed by an embossing in the sliding surface 5, independent of the shape of the rear transition area 17. Thus, the base 19 of the recess 7 is formed by the sliding surface 5. Fig. 4 shows a possible design of a longitudinally 8 front transition area 16 of a recess 7. This area is stepped from the recess 7 towards the sliding surface 18. The step shape itself can be right-angled or inclined, as indicated by the dashed lines. An advantage of this design is the protection against unintentional detachment of a push-off aid 21 located behind the step. In the illustrated embodiment, the push-off aid 21 is optionally attached with a releasable fastener 25 and can have different heights; preferably, it is flush with the sliding surface or projects slightly beyond it. Furthermore, the step can serve as an additional aid for climbing or pushing off, as it can engage with the surface. In the illustrated embodiment, the recess 7 is formed by a type of cutout, e.g., a milled groove, independent of the shape of the front transition area 16.This creates the base area 19 of the recess 7 by the layer 4 below it. Fig. 5 shows a possible embodiment of a recess 7 of a ski 1 in side view. The depth 15 of the recess 7 varies in the longitudinal direction 8 and forms additional areas 26 to support a push-off aid 21. The areas 26 thus formed can be wavy, sawtooth-shaped, or even roof-shaped. The base area 19 is thereby partially / 28 N2019 / 33700-AT-00 is formed by the underlying layer 4, namely in the deepest parts of the recess 7. In a further embodiment, not shown, it would also be possible to form the recess 7 by an arc-shaped or approximately trapezoidal shape in the longitudinal direction 8. Fig. 6 shows a particular embodiment of a recess 7 in a ski 1 in cross-section. Here, the depth 15 of the recess 7 decreases in the width direction 9 from the longitudinal edge 33 towards the center of the ski. Two possible embodiments are shown: one approximately trapezoidal in width 9, and the other an arcuate recess 7. This allows a push-off aid 21 to be attached at a slight angle to the ground 28, which is advantageous when frequently skiing on the outside or inside edge. Furthermore, the ski core 3, the top rib 29 surrounding the ski core 3, and the layer 4 located beneath the glide surface 5 are shown in simplified form in the illustrated view. Fig. 7 shows a possible arrangement of a release aid 21 in the recess 7 in the release zone 12, viewed from below. This illustrates that a user can freely select the position, shape, and maximum length 23 or maximum width 24 of at least one release aid 21, and thus also its usable effective area 22. A further release aid 21 is indicated by dashed lines, which can also be positioned freely. Figures 8 and 9 show a further embodiment of a fastening means 25 for a push-off aid 21 in side and bottom views. In this embodiment, the push-off aid 21 is fastened by means of a band 27 that encloses the ski 1 in the area of ​​the recess 7 around the cross-sectional circumference 30. The band 27 itself can also be designed as the push-off aid 21 on its own, or the push-off aid 21 can be integrated into the band 27. By displacing the band 27 in the longitudinal direction 8 or the lateral direction 9, the section with the push-off aid 21 in the recess 7 can also be repositioned in the aforementioned directions, as indicated by dashed lines in Figures 8 and 9. The band 27 itself can be self-locking or attached to the ski by means of a hook-and-loop fastener or similar methods. Furthermore, it can also be designed in a cuff-like shape and fastened over / 28 N2019 / 33700-AT-00 the ski is turned inside out. Preferably, the band 27 is made of an elastic or stretchable material in order to ensure optimal hold on the base body 2 by means of its stretched state. Fig. 10 shows a simplified cross-section of a ski 1 in the area of ​​the recess 7 and its cross-sectional circumference 30. A band 27 is attached around the ski 1 in the push-off zone 12 in the area of ​​the recess 7, enclosing the cross-sectional circumference 30. A possible push-off aid 21 is also located on the band 27. By displacing the band 27 by the cross-sectional circumference 30, the push-off aid 21 can be repositioned by the amount of the displacement, as indicated by the dashed lines. Thus, the push-off aid 21 can also be removed by sliding it out of the recess 7. The exemplary embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiment variants, but rather various combinations of the individual embodiment variants are also possible and this possibility of variation lies within the skill of the person skilled in this technical field due to the teaching on technical action by the present invention. The scope of protection is defined by the claims. However, the description and drawings must be consulted for the interpretation of the claims. Individual features or combinations of features from the different embodiments shown and described can, in themselves, represent independent inventive solutions. The problem underlying these independent inventive solutions can be found in the description. All references to value ranges in the present description are to be understood as encompassing any and all sub-ranges thereof; e.g., the reference 1 to 10 is to be understood as including all sub-ranges, starting from the lower limit 1 and the upper limit 10, i.e., all sub-ranges begin with a lower limit of 1 or greater and end / 28 N2019 / 33700-AT-00 with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10. Finally, for the sake of clarity, it should be noted that, for a better understanding of the structure, some elements have been shown not to scale and / or enlarged and / or reduced in size. / 28 N2019 / 33700-AT-00 Reference symbol list Ski 30 Cross-sectional circumference Base body 31 Front glide section Ski core 32 Rear glide section Layer 33 Longitudinal edge sliding surface Wide recess Longitudinal direction Broad direction Front end Rear end Push-off zone Length Width Depth Front transition area Rear transition area Sliding surface Base area Total area Anti-slip climbing or push-off aid Effective surface Length Width Fastener Area Strap Substrate Top chord

Claims

1. Claims 1. Ski (1), in particular cross-country ski, with a shaping base body (2) and a sliding surface (5) arranged on the underside of the base body (2), which extends in the longitudinal direction (8) and width direction (9) of the ski (1), wherein the sliding surface (5) has a front and a rear sliding section (31, 32) with respect to the longitudinal direction (8) and at least one recess (7) is formed in a push-off zone (12) between the front and rear sliding sections (31, 32), which recess (7) is provided for receiving at least one anti-slip climbing or push-off aid (21), wherein the at least one recess (7) extends continuously over the entire width (6) of the sliding surface (5) of the ski (1), characterized in that a depth (15) of the at least one recess (7), starting from at least one of the longitudinal edges (33) of the ski (1) in The width direction (9) decreases towards the center of the ski (1).

2. Ski (1), in particular cross-country ski, with a shaping base body (2) and a sliding surface (5) arranged on the underside of the base body (2), which extends in the longitudinal direction (8) and lateral direction (9) of the ski (1), wherein the sliding surface (5) has a front and a rear sliding section (31, 32) with respect to the longitudinal direction (8) and at least one recess (7) is formed in a push-off zone (12) between the front and rear sliding sections (31, 32), in which recess (7) at least one anti-slip climbing or push-off aid (21) is arranged, wherein the at least one recess (7) extends continuously over the entire width (6) of the sliding surface (5) of the ski (1), characterized in that a depth (15) of the at least one recess (7), starting from at least one of the longitudinal edges (33) of the ski (1) in the lateral direction (9) towards the center of the Skis (1) decreases.

3. Ski (1) according to claim 2, characterized in that a total area (20) of the at least one recess (7) is larger than a (backslip-inhibiting) effective area (22) of the at least one backslip-inhibiting climbing or pushing-off aid (21), and that the at least one backslip-inhibiting climbing or pushing-off aid (21) can be positioned freely in the longitudinal direction (8) and / or the lateral direction (9) in the at least one recess (7).

4. Ski (1) according to claim 2 or 3, characterized in that a length (13) of the at least one recess (7) relating to the longitudinal direction (8) of the ski (1) is greater than a maximum length (23) of the anti-slip climbing or pushing aid (21) relating to the longitudinal direction (8) of the ski (1).

5. Ski (1) according to one of claims 2 to 4, characterized in that a width (14) of the at least one recess (7) relating to the lateral direction (9) of the ski (1) is larger than a maximum width (24) of the anti-slip climbing or pushing aid (21) relating to the lateral direction (9) of the ski (1).

6. Ski (1) according to claim 4, characterized in that the greatest length (23) of the at least one anti-slip climbing or pushing aid (21) is between 40% and 90% of the length (13) of the at least one recess (7).

7. Ski (1) according to claim 5, characterized in that the greatest width (24) of the at least one anti-slip climbing or pushing aid (21) is between 20% and 90% of the width (14) of the at least one recess (7).

8. Ski (1) according to one of the preceding claims, characterized in that a transition area (16) at the front with respect to the longitudinal direction (8) between the recess (7) and the sliding surface (18) of the sliding base (5) is stepped. 27 / 28 Δοηοη / ςηη09_ΔΤ_ηη LAST CLAIMS] 9. Ski (1) according to one of the preceding claims, characterized in that a transition area (17) located at the rear with respect to the longitudinal direction (8) between the at least one recess (7) and the sliding surface (18) of the sliding layer (5) is flattened in the longitudinal direction (8).

10. Ski (1) according to one of the preceding claims, characterized in that a base surface (19) of the at least one recess (7) has a sawtooth or wave-shaped contour in section in longitudinal direction (8).

11. Ski (1) according to one of claims 2 to 10, characterized in that the at least one anti-slip climbing or pushing aid (21) can be released as required and repositioned as desired by means of at least one fastening means (25) in the at least one recess (7).

12. Ski (1) according to claim 11, characterized in that the fastening means (25) is selected from the group consisting of pressure-sensitive adhesive, adhesive nanostructures, hook and loop fastener, magnetic adhesive, or electrostatic adhesive.

13. Ski (1) according to claim 11 or 12, characterized in that the fastening means (25) has a band (27) which encloses a cross-sectional circumference (30) of the ski (1) in the area of ​​the recess (7) and is displaceable as required in the longitudinal direction (8) and in relation to the cross-sectional circumference (30) of the ski (1).

14. Ski (1) according to one of claims 2 to 13, characterized in that the at least one anti-slip climbing or push-off aid (21) is formed by a climbing skin with synthetic or natural fibers.