CA1120965A - Ski, in particular a cross-country or excursion ski - Google Patents
Ski, in particular a cross-country or excursion skiInfo
- Publication number
- CA1120965A CA1120965A CA000334505A CA334505A CA1120965A CA 1120965 A CA1120965 A CA 1120965A CA 000334505 A CA000334505 A CA 000334505A CA 334505 A CA334505 A CA 334505A CA 1120965 A CA1120965 A CA 1120965A
- Authority
- CA
- Canada
- Prior art keywords
- ski
- fluff
- wax
- country
- plastics material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63C—SKATES; SKIS; ROLLER SKATES; DESIGN OR LAYOUT OF COURTS, RINKS OR THE LIKE
- A63C5/00—Skis or snowboards
- A63C5/04—Structure of the surface thereof
- A63C5/056—Materials for the running sole
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)
- Golf Clubs (AREA)
- Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
This invention relates to a novel cross-country or excursion ski. The bottom of the ski, at least at the middle portion of the ski, that is, at the portion loaded by the foot, is made of a hard and elastic, massive polyacetal plastics material, whose surface is shaped as fluffy with sharp edges, the fluff length being approximately 0.01 to 0.1 mm. This construction provides the ski with good glide characteristics and good hold without the use of ski wax, which was not possible with the prior art devices.
This invention relates to a novel cross-country or excursion ski. The bottom of the ski, at least at the middle portion of the ski, that is, at the portion loaded by the foot, is made of a hard and elastic, massive polyacetal plastics material, whose surface is shaped as fluffy with sharp edges, the fluff length being approximately 0.01 to 0.1 mm. This construction provides the ski with good glide characteristics and good hold without the use of ski wax, which was not possible with the prior art devices.
Description
~6~965 1 The present invention relates to a ski, in particular a cross-country or excursion ski.
The use of plastics material for ski bottoms was introduced in skis for downhill running, but today almost exclusively plastics bottoms are also used for cross-country skis. A serious drawback of plastics bottoms in such skis is that the plastics yive poor hold. Attempts have been made to solve this problem along two main lines.
One of the main lines consists of making the bottom 1~ of the ski relatively coarsely grooved~ whereby a grooving has been concerned that is readily visible to the eye.
These skis have not been successful in practice, obviously owing to unsatisfactory glide. ~ closely related solution is that a fluffy fabric is used with a sli~ht inclination resis~ance in a certain direction. Such a ski bottom is~ however, expensive -to manufacture, besides which the wear resistance of the fabric has proved insufficient. Nor is it possible to replace the ~abric ~y means of reasonable operations.
The other main line has consisted of attempts~ in different ways, to make the bottom of the ski porous in ordex that the wax should adhere to the ski better. An example of solutions in this direction is disclosed in the Finnish Announce-ment Publication No. 48,676. In this way, true enough, sat~
isfactory results have been obtained in respect of the hold, but a requirement is, however, careful application of wax, which involves a relatively great trouble for the layman, especially because the wax is in any case worn and must be renewed.
The object of the present invention is to provide a new cross-country s]ci that has both good glide and good hold without the use of the ski wax.
B
~L~Z(~65 1 The ski in accordance with the present invention is characterized in that its bottom, at least at the middle por-tion of the ski, i.e. at the portion loaded by the foot, is made of a hard and elastic, massive plastics material, whose surface is shaped as fluffy with sharp edges, the fluff length being approximately 0.0l to 0.l mm.
The plastics material is pre~erably polyacetal plastics or an elastomer with corresponding propertiesD
The term "fluffy" is in ~his connection not to be misunderstood as meaning a fluff similar to that described, e.gO, in the Finnish Patent 43,401. In the present case, viz., the bottom face of the ski feels completely smooth when it is stroked with the hand, but light passing parallel to the ski bottom discloses the nature of the bottom, which has ~ screen~
like a~pearance by the effect of the light shadows~. T~e ~lu~
moves easily and changes direction even when touched l:ightly by the finger, which is in appropriate illumination seen as the place concerned becoming darker or lighter.
When the ski glides forwards on crystals of ice, the ~ fluff is bent and its friction is low. The layer of water that is formed between the ski and the crystals of ice likewise improves the glide in the same way as in the case of skis provided with wax, because the short fluff does not break the layer of water. When the glide has stopped, the fluf again assumes its original shape, when the foot is pressed down, and by means of its hard and sharp edges bites into the ice and gives a surprisingly good hold.
The desired fluff can be produced advantageously by means of so-called vibration grinding, which takes place in a totally haphazard way as regards the direction, so that the fluff 6~i 1 does not receive an advance inclination in any direction. It has been noticed that if the fluff is, e,g.~ given ~n advance inclination b~ckwards, the hold is decreased remarkably, because the fluff is not able to raise itself sufficiently~ The same phonomenon tends to occur if -the fluff is too long in relation to its thickness; this begins to be noticed when the ratio of length to thickness exceeds 2:l. This drawback is avoided most reliably if the length of fluff is maintained within the range of O.Ol to 0.05 ~m. A manufacturing-technical advantage due to the fact that the fluff is complelely irregular is that during installation of the bottom layer that ski bottom has no "front end" or "rear end 71 .
In order to obtain su-fficient hold, it is not necessary to manufacture more than the so-called foot-loaded portion of the ski bottom in the described way, whereas the front and rear parts of the bottom may be untreated or, as in skis so far, e~g., made of polyethylene, which is considerably less expensive than, e.g., polyacetal. In this way the glide of the ski also becomes better. In view of so-called week-end skiers it would, ~ however, also be acceptable to make the entire bottom of the ski fluffy in the described way.
When skiing on tracks with lively traffic of skis with ski wax, detached ski wax present on the track tends to adhere to the fluff and to impair its functioning. This can be counter-acted by mixing into the plastics material an agent that rejects ski wax. Such an agent is, e.g., polytetrafluoroethylene ~PTFE), which can be mixed into the plastics material in the form of grains. The quantity of polytetrafluoroethylene may be appropriately approximately 20 per cent.
The invention will be described below with reference ~ ~L2~)~65 1 to the exemplifying embodiment shown in the attached drawing.
Figure l shows a bottom of a ski in accordance with the inventi:on, Figures 2 and 3 show a schematical enlarged view of the portion of the ski bottom that provides the hold, during gliding and during hold, respectively, and Figure 4 is a schematical view of the way in which an agent rejec-ting ski wax may be mixed into the ski bottom.
The ski bottom of a ski in accordance with the invention is denoted with numeral l, the foot-loaded portion, which is mainly responsible for the hold of the ski, with numeral 2, the front part of the bottom with 3, and the rear part with 4. The front part and the rear part are made of, e.g., polyethylene, as in known skis. The middle, foot-loaded, part 2 is made of hard and elastic, massive polyacetal plastics or of an elastomer of similar properties, and its surrace is ground in order to produce elastic fluff 5 with sharp edges, as is shown schematic-ally in Figures 2 to 4. The hardness of the material gives the individual ~luff hairs 5 good resistance to wear, and the elasticity provides the desired glide-hold effect. The length h of the individual fluff hairs may vary within the range of O.Ol to O.l mm, but in order to obtain good so-called form memory, the ratio of length h to the width or thickness b of the hair 5 at the root should preferably not exceed about 2:l.
The fluff is appropriately produced by means of a manually operated vibra-tion device making use of grinding paper of appropriate coarseness in order to produce, as regards the direction, a haphazardly random grinding, which has proved give the best results. It is also possible to use totally mechanical grinding, in which case the configuration of the fluff becomes regular, e.g., in the form of transverse or longitudinal "grooyes", but the final result is then somewhat nferlor .
It has been noticed that if the fluEf is, in the way indicated above, ground to a length closer to the gi~en upper limit of 0.1 mm, a relatively high proportion of the fluff hairs become so narrow that they do not straighten up sufficiently after the gliding stage of the ski, and therefore it is preferred that the fluff length be limited to about 0.01 to 0.05 mm.
In order to avoid adhesion of ski wax present on the ski track to the fluff with resulting elimination of its effect, an agent rejecting ski wax, e.g., polytetrafluoroethylene in the form of grains 6, can be mixed intothe plastics material, as is implied schematically in Figure 4. It has been noticed that an appropriate quantity is 20 per cent by weight, but other values may of course also be used. An extra advantage of this solution is that the fluff is substantially retained with-out re-grinding, in spite of wear, which wear, due to the hardness of the plastics material, true enough, takes place slowly but, nevertheless, cannot be avoided.
The use of plastics material for ski bottoms was introduced in skis for downhill running, but today almost exclusively plastics bottoms are also used for cross-country skis. A serious drawback of plastics bottoms in such skis is that the plastics yive poor hold. Attempts have been made to solve this problem along two main lines.
One of the main lines consists of making the bottom 1~ of the ski relatively coarsely grooved~ whereby a grooving has been concerned that is readily visible to the eye.
These skis have not been successful in practice, obviously owing to unsatisfactory glide. ~ closely related solution is that a fluffy fabric is used with a sli~ht inclination resis~ance in a certain direction. Such a ski bottom is~ however, expensive -to manufacture, besides which the wear resistance of the fabric has proved insufficient. Nor is it possible to replace the ~abric ~y means of reasonable operations.
The other main line has consisted of attempts~ in different ways, to make the bottom of the ski porous in ordex that the wax should adhere to the ski better. An example of solutions in this direction is disclosed in the Finnish Announce-ment Publication No. 48,676. In this way, true enough, sat~
isfactory results have been obtained in respect of the hold, but a requirement is, however, careful application of wax, which involves a relatively great trouble for the layman, especially because the wax is in any case worn and must be renewed.
The object of the present invention is to provide a new cross-country s]ci that has both good glide and good hold without the use of the ski wax.
B
~L~Z(~65 1 The ski in accordance with the present invention is characterized in that its bottom, at least at the middle por-tion of the ski, i.e. at the portion loaded by the foot, is made of a hard and elastic, massive plastics material, whose surface is shaped as fluffy with sharp edges, the fluff length being approximately 0.0l to 0.l mm.
The plastics material is pre~erably polyacetal plastics or an elastomer with corresponding propertiesD
The term "fluffy" is in ~his connection not to be misunderstood as meaning a fluff similar to that described, e.gO, in the Finnish Patent 43,401. In the present case, viz., the bottom face of the ski feels completely smooth when it is stroked with the hand, but light passing parallel to the ski bottom discloses the nature of the bottom, which has ~ screen~
like a~pearance by the effect of the light shadows~. T~e ~lu~
moves easily and changes direction even when touched l:ightly by the finger, which is in appropriate illumination seen as the place concerned becoming darker or lighter.
When the ski glides forwards on crystals of ice, the ~ fluff is bent and its friction is low. The layer of water that is formed between the ski and the crystals of ice likewise improves the glide in the same way as in the case of skis provided with wax, because the short fluff does not break the layer of water. When the glide has stopped, the fluf again assumes its original shape, when the foot is pressed down, and by means of its hard and sharp edges bites into the ice and gives a surprisingly good hold.
The desired fluff can be produced advantageously by means of so-called vibration grinding, which takes place in a totally haphazard way as regards the direction, so that the fluff 6~i 1 does not receive an advance inclination in any direction. It has been noticed that if the fluff is, e,g.~ given ~n advance inclination b~ckwards, the hold is decreased remarkably, because the fluff is not able to raise itself sufficiently~ The same phonomenon tends to occur if -the fluff is too long in relation to its thickness; this begins to be noticed when the ratio of length to thickness exceeds 2:l. This drawback is avoided most reliably if the length of fluff is maintained within the range of O.Ol to 0.05 ~m. A manufacturing-technical advantage due to the fact that the fluff is complelely irregular is that during installation of the bottom layer that ski bottom has no "front end" or "rear end 71 .
In order to obtain su-fficient hold, it is not necessary to manufacture more than the so-called foot-loaded portion of the ski bottom in the described way, whereas the front and rear parts of the bottom may be untreated or, as in skis so far, e~g., made of polyethylene, which is considerably less expensive than, e.g., polyacetal. In this way the glide of the ski also becomes better. In view of so-called week-end skiers it would, ~ however, also be acceptable to make the entire bottom of the ski fluffy in the described way.
When skiing on tracks with lively traffic of skis with ski wax, detached ski wax present on the track tends to adhere to the fluff and to impair its functioning. This can be counter-acted by mixing into the plastics material an agent that rejects ski wax. Such an agent is, e.g., polytetrafluoroethylene ~PTFE), which can be mixed into the plastics material in the form of grains. The quantity of polytetrafluoroethylene may be appropriately approximately 20 per cent.
The invention will be described below with reference ~ ~L2~)~65 1 to the exemplifying embodiment shown in the attached drawing.
Figure l shows a bottom of a ski in accordance with the inventi:on, Figures 2 and 3 show a schematical enlarged view of the portion of the ski bottom that provides the hold, during gliding and during hold, respectively, and Figure 4 is a schematical view of the way in which an agent rejec-ting ski wax may be mixed into the ski bottom.
The ski bottom of a ski in accordance with the invention is denoted with numeral l, the foot-loaded portion, which is mainly responsible for the hold of the ski, with numeral 2, the front part of the bottom with 3, and the rear part with 4. The front part and the rear part are made of, e.g., polyethylene, as in known skis. The middle, foot-loaded, part 2 is made of hard and elastic, massive polyacetal plastics or of an elastomer of similar properties, and its surrace is ground in order to produce elastic fluff 5 with sharp edges, as is shown schematic-ally in Figures 2 to 4. The hardness of the material gives the individual ~luff hairs 5 good resistance to wear, and the elasticity provides the desired glide-hold effect. The length h of the individual fluff hairs may vary within the range of O.Ol to O.l mm, but in order to obtain good so-called form memory, the ratio of length h to the width or thickness b of the hair 5 at the root should preferably not exceed about 2:l.
The fluff is appropriately produced by means of a manually operated vibra-tion device making use of grinding paper of appropriate coarseness in order to produce, as regards the direction, a haphazardly random grinding, which has proved give the best results. It is also possible to use totally mechanical grinding, in which case the configuration of the fluff becomes regular, e.g., in the form of transverse or longitudinal "grooyes", but the final result is then somewhat nferlor .
It has been noticed that if the fluEf is, in the way indicated above, ground to a length closer to the gi~en upper limit of 0.1 mm, a relatively high proportion of the fluff hairs become so narrow that they do not straighten up sufficiently after the gliding stage of the ski, and therefore it is preferred that the fluff length be limited to about 0.01 to 0.05 mm.
In order to avoid adhesion of ski wax present on the ski track to the fluff with resulting elimination of its effect, an agent rejecting ski wax, e.g., polytetrafluoroethylene in the form of grains 6, can be mixed intothe plastics material, as is implied schematically in Figure 4. It has been noticed that an appropriate quantity is 20 per cent by weight, but other values may of course also be used. An extra advantage of this solution is that the fluff is substantially retained with-out re-grinding, in spite of wear, which wear, due to the hardness of the plastics material, true enough, takes place slowly but, nevertheless, cannot be avoided.
2~ Another possibility is to impregnate the plastics material with, e.g., zinc stearate, appropriately in a quantity of about 3 per cent by weight, whereby the zinc stearate also counteracts formation of ice especially at temperatures of about 0C to -1C.
Claims (7)
1. A ski, in particular a cross-country or excursion ski, characterized in that its bottom, at least at the middle portion of the ski, i.e. at the portion loaded by the foot, is made of a hard and elastic, massive polyacetal plastics material, whose surface is shaped as fluffy with sharp edges, the fluff length being approximately 0.01 to 0.1 mm.
2. A ski as claimed in claim 1, characterized in that the ratio of fluff length to fluff thickness does not exceed approximately 2:1.
3. A ski as claimed in claim 1, characterized in that the fluff length is approximately 0.01 to 0.05 mm.
4. A ski as claimed in claim 1, 2 or 3, characterized in that said hard and elastic, massive polyacetal plastics material extends substantially over the entire length of the ski bottom.
5. A ski as claimed in claim 1, characterized in that an agent rejecting ski wax has been mixed into the bottom material.
6. A ski as claimed in claim 5, characterized in that the agent rejecting ski wax consists of polytetrafluoroethylene, which is mixed into the bottom material in the form of grains.
7. A ski as claimed in claim 5, characterized in that the agent rejecting ski wax is zinc stearate, preferably as a quantity of about 3 percent by weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI782792A FI782792A (en) | 1978-09-12 | 1978-09-12 | BOTTEN FOER SKIDA SPECIELLT TERRAENG OCH FAERDSKIDA |
| FI782,792 | 1978-09-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1120965A true CA1120965A (en) | 1982-03-30 |
Family
ID=8512001
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000334505A Expired CA1120965A (en) | 1978-09-12 | 1979-08-27 | Ski, in particular a cross-country or excursion ski |
Country Status (9)
| Country | Link |
|---|---|
| AT (1) | AT366918B (en) |
| CA (1) | CA1120965A (en) |
| CH (1) | CH640741A5 (en) |
| DE (1) | DE2934309A1 (en) |
| FI (1) | FI782792A (en) |
| FR (1) | FR2435957A1 (en) |
| IT (1) | IT1165300B (en) |
| NO (1) | NO792802L (en) |
| SE (1) | SE7907430L (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4540195A (en) * | 1983-02-23 | 1985-09-10 | Ramu International | Cross-country ski sole |
| US4595215A (en) * | 1982-02-19 | 1986-06-17 | Karhu-Titan Oy | Coating material and coating for a ski, for variable snow conditions, and method of manufacture of same |
| US4635954A (en) * | 1984-05-25 | 1987-01-13 | Blizzard Gesellschaft M.B.H. | Ski with improved running surface |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3005171C2 (en) * | 1980-02-12 | 1986-07-24 | Franz Völkl oHG, 8440 Straubing | Skiing surface training with a low-pressure polyethylene outsole exhibiting a roughening |
| AT383745B (en) * | 1984-08-01 | 1987-08-10 | Fischer Gmbh | BASE FOR SKIS |
| AT388873B (en) * | 1986-03-25 | 1989-09-11 | Blizzard Gmbh | Running-surface coating for skis |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2414185A1 (en) * | 1974-03-23 | 1975-10-09 | Loba Holmenkol Chemie Lhc | RUNNING SURFACE FOR SPORTS EQUIPMENT FOR GLIDING AND WALKING OVER SNOW AND ICE SURFACES, E.G. SKI |
| DE2623852A1 (en) * | 1975-06-17 | 1976-12-23 | Fischer Gmbh | SKI |
| DE2610522A1 (en) * | 1976-03-12 | 1977-09-15 | Voelkl Ohg Franz | Cross country ski with plastics running surface - has fluted central area with inclined pattern hindering reverse motion |
-
1978
- 1978-09-12 FI FI782792A patent/FI782792A/en unknown
-
1979
- 1979-08-24 DE DE19792934309 patent/DE2934309A1/en not_active Ceased
- 1979-08-27 CA CA000334505A patent/CA1120965A/en not_active Expired
- 1979-08-29 NO NO792802A patent/NO792802L/en unknown
- 1979-09-05 IT IT25502/79A patent/IT1165300B/en active
- 1979-09-07 FR FR7922439A patent/FR2435957A1/en active Granted
- 1979-09-07 AT AT0592979A patent/AT366918B/en not_active IP Right Cessation
- 1979-09-07 CH CH809879A patent/CH640741A5/en not_active IP Right Cessation
- 1979-09-07 SE SE7907430A patent/SE7907430L/en not_active Application Discontinuation
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4595215A (en) * | 1982-02-19 | 1986-06-17 | Karhu-Titan Oy | Coating material and coating for a ski, for variable snow conditions, and method of manufacture of same |
| US4540195A (en) * | 1983-02-23 | 1985-09-10 | Ramu International | Cross-country ski sole |
| US4635954A (en) * | 1984-05-25 | 1987-01-13 | Blizzard Gesellschaft M.B.H. | Ski with improved running surface |
Also Published As
| Publication number | Publication date |
|---|---|
| SE7907430L (en) | 1980-03-13 |
| DE2934309A1 (en) | 1980-03-27 |
| IT7925502A0 (en) | 1979-09-05 |
| IT1165300B (en) | 1987-04-22 |
| NO792802L (en) | 1980-03-13 |
| CH640741A5 (en) | 1984-01-31 |
| FR2435957B1 (en) | 1983-01-14 |
| FR2435957A1 (en) | 1980-04-11 |
| FI782792A (en) | 1980-03-13 |
| AT366918B (en) | 1982-05-25 |
| ATA592979A (en) | 1981-10-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |