WO2000010413A1

WO2000010413A1 - Combination of binding and ski boot

Info

Publication number: WO2000010413A1
Application number: PCT/FI1999/000685
Authority: WO
Inventors: Lasse Gunnar FLÖJT
Original assignee: Floejt Lasse Gunnar
Priority date: 1998-08-18
Filing date: 1999-08-18
Publication date: 2000-03-02
Also published as: AU5375099A; FI981771A; FI981771A0

Abstract

The present invention relates to the combination of a ski boot (1) and a ball-of-the-foot binding (9), wherein the essentially inflexible sole (5) of said ski boot constitutes an angle (6) of at least 30° at the ball of the foot and an attachment point (2) for a connecting shaft (3) is situated below the ball of the foot. The binding (9) includes adjustable elastic means (7) which via supporting surfaces (4) at the underside of the sole provide the possibility to select the angle (8) between the ski and the boot to be at least 0 to 30° when the ski is raised free of the track.

Description

COMBINATION OF BINDING AND SKI BOOT

The present invention relates to a combination of a ski boot and a binding, wherein the attachment point of the binding is located below the ball of the foot and the combination includes an adjustment device, which adjusts the interrelation between the ski and the boot to be at least between 0 to 30° as desired when the ski is moved forward. An essentially inflexible sole of said ski boot constitutes an intersecting angle at the ball of the foot, so that the front and heel parts of the boot remain in a mutually skew angle.

Today a known arrangement for attaching a ski boot to a binding in both classic style skiing and skate style skiing is based on a toe binding attaching the ski boot at its toe to the ski. Said toe binding includes a supporting elastic means, which after a push or take-off quickly repositions the ski into a parallel position in relation to the sole of the boot .

In known skate ski boots intended for cross-country skiing a rather stiff straight sole is used which is attached to the binding at its toe portion. When one tries, using such a stiff sole skating boot, to perform a take-off using the ball of the foot the muscles of the foot and the ankle will be considerably strained. When, using a straight bottom stiff sole, one performs a take-off using the ball of the foot, the elastic supporting means included in said toe binding will turn the ski to touch the heel of the boot when the foot is raised ^'free from the ground after the take-off (in which case the point of the ski tends to remain in contact with the snow) . In this situation the foot must be quickly turned to a horizontal position (so that the point of the ski gets free from the snow) , in order to make it possible to move the ski forwards in the air. Instead of using this difficult take-off method utilizing the ball of the foot, which method makes the muscles of the foot, ankle and leg tired, one in skate skiing with a toe binding in practice in most cases performs a takeoff with the whole sole and, after the take-off, lifts the ski free from the ground with the foot in a horizontal position. This skiing technique, however, is slow in tempo so that a different binding-and-boot solution is needed for a faster tempo in skate skiing.

In classic style skiing one must perform the take-off using the ball of the foot in order to create a necessary grip. Since a take-off with a straight stiff sole boot would be too strenous for the foot the sole of a commonly used prior art classic skiing style boot comprises a flexible sole so that the boot will bend at the ball of the foot at the take-off. Generally, the bending will take place so that the normally straight sole of the boot bends to curve at the ball of the foot during the take-off, or, as disclosed in Finnish patent application FI 763371, a sole which normally includes a bend at the ball of the foot (said sole being attached to the ski by the toe portion) straightens up during the sliding stage under influence of the weight of the skier and recovers to ist bend during the take-off at the ball of the foot due to the elasticity properties of the boot. A classic ski boot attached to a toe binding touches the ski at the ball of the foot during the stage of take-off by the ball of the foot (and the ski is touching the track) , and in the subsequent stage of lifting the foot after the take-off the ball of the foot will first come off the ski and only thereafter the ski will come clear off the track due to the rise of the toe of the boot. This detachment of the ski from the track which occurs later than that of the ball of the foot will bring about an extra time lag to the skiing rhythm and thus it is a considerable drawback especially in fast situations in even faster cross-country skiing competitions, in ascents and in curving downhill tracks. The present invention provides a decisive improvement to the described drawbacks. For this purpose the combination of boot and ball-of-the-foot binding according to the present invention is characterized by the features disclosed in the appended claims 1 to 6.

The following features are considered to be the most important advantages of the present invention:

- The stage of take-off becomes more efficient in skate skiing. The combination of a ski boot and a ball-of-the- foot binding provides the possibility for a more efficient final stage of the take-off using the ball of the foot and therefore it brings an important possibility of adding speed in skate skiing.

- In skate skiing the twisting strain on the foot within the boot during a take-off by the ball of the foot decreases, since the foot no longer "wrenches" the boot from inside during a take-off by the ball of the foot, but the boot's position is controlled by the sole. At the same time the need for a continual take-off by the whole feet is eliminated, and thus no static stress is caused to the immobile foot.

- A better and quicker control of the ski during the final stage of the take-off in skate skiing. During the final stage of the take-off the ski does not turn more to the side, because the binding does not include any such elastic device which would turn the ski back into contact with the boot's heel and thus more to the side during the take-off. Also, the ski will faster come free from the snow in the final stage of the take-off, because the binding is fastened under the ball of the foot and not at the toe of the boot. Together these qualities facilitate a quicker tempo in skate skiing.

- A better control of the ski when the ski is brought forwards in skate skiing. The new combination of a boot and a ball-of-the-foot binding provides the possibility to adjust the position of the ski in the air to different positions in relation to the boot at an angle of at least 0 to 30°, and thus the possibility to choose an optimal po- sition of the ski in the air, taking into consideration the technique of skiing and the air drag.

- The take-off stage becomes easier in classic skiing. The boot for classic skiing in the combination of boot and ball-of-the foot binding does not bend at the ball of the foot during a take-off, and thus any bending strain in the foot is avoided.

- In classic skiing the ski comes free off the track quicker at the end of the take-off. The ski comes free off the track at once when the ball of the foot has been raised, not together with the toe of the boot as is the case for toe bindings. This makes a faster tempo possible in classic skiing, which is favorable especially in upward slopes and in fast curves.

The invention will now be explained in detail with reference to the appended drawing.

Figure 1 shows the main features of a ski boot adapted for a ball-of-the-foot binding, Figure 2 shows a ski boot fastened to the ball-of-the-foot binding when the ski is in the air, Figure 3 shows the basic solution for one ball-of-the-foot binding, and Figure 4 shows a detail of one arrangement for attaching the ball-of-the-foot binding and the ski boot.

Figure 1 shows the main features of a ski boot 1 intended for a ball-of-the-foot binding, said boot including an essentially inflexible sole 5. At the ball of the foot the sole forms a bend 6 of at least 30° in relation to the heel portion of the boot. Below the ball of the foot there are attachment devices 2 and 2a for connecting a connecting shaft 3 of the ball-of-the-foot binding to the boot so that it can be rotated. At the bottom surface of the sole there are contact surfaces 4 for elastic support means 7 included in the binding. The sole of the boot includes supporting ridges 13, which provide a necessary stiffness to the boot and supporting surfaces for lateral forces.

Figure 2 shows a ski boot 1 attached to the ball-of-the-foot binding 9 when the ski 10 is raised in the air. Adjustable elastic support means 7 included in the binding support the ski in relation to the boot by means of supporting surfaces 4 , which are located at the underside of the sole . Said elastic support means 7 are adjustable so that an angle 8 of at least 0 to 30° between the ski and the boot can be chosen when the ski is in the air. In the sole a longitudinal groove remains between supporting ridges 13, which groove continues towards the point of the ski past said attachment point 2 and acts as a lateral control means in co-operation with side surfaces 15 of the ball-of-the-foot binding and an extension bead 11 of the binding.

Figure 3 shows one basic solution of the ball-of-the-foot binding 9, which binding includes a connecting shaft 3, to which the boot is attached via attachment devices 2 and 2a which are located in the boot. The binding includes elastic supporting means 7, both of which being separately adjustable to different positions by means of alternative attachment points 12. The side surface 15 of the binding simultaneously constitutes lateral supporting surfaces for lateral guides, and it is compatible with said supporting ridges 13 in the sole. Said lateral supporting surfaces can be extended, with an extension bead 11, to the heel of the boot.

Figure 4 shows a detail of a solution for attaching the ball- of-the-foot binding 9 to the ski boot 1. The supporting ridge 13 of the sole includes a shaft recess 2, in which said connecting shaft 3 of the binding fits in snugly. Said connecting shaft is locked in said recess with a longitudinally movable pin 2a so that said attaching shaft has a possibility to rotate. Said pin 2a is operated by means of a lever 14. Especially it should be observed that said connecting shaft also can be located in the boot and the attachment devices for said shaft in the binding. The exact location for said connecting shaft may vary at different points below the ball of the foot and it may also be situated below the toe bone. Also the flexible elastic supporting devices disclosed in the figures may be manufactured of other materials too and have different forms and stiffness, provided that their impact on the control of the ski corresponds to the one described here.

Claims

1. A boot (1) especially adapted for a ball-of-the-foot binding for cross-country skiing, c h a r a c t e r i z e d in that an attachment means (2) for a connecting shaft (3) is located below the ball of the foot and that a bend having an angle (6) of at least 30┬░ is arranged, in a position at the ball of the foot, in the essentially inflexible sole (5) of said boot, and that said sole comprises contact surfaces (4) for elastic supporting devices (7) included in the ball-of- the-foot binding, said devices being intended for adjusting the angle between the boot and the ski when the ski is raised free of the track.

2. A ski boot as defined in claim 1, c h a r a c t e r i z e d in that said connecting shaft (3) is arranged in said boot (1) and that said attachment means (2) and (2a) are arranged in the ball-of-the foot binding (9) .

3. A boot (1) especially adapted for a ball-of-the-foot binding for cross-country skiing, c h a r a c t e r i z e d in that an attachment means (2) for a connecting shaft (3) is located below the toe bone and that a bend having an angle (6) of at least 30┬░ is arranged, in a position at the ball of the foot, in the essentially inflexible sole (5) of said boot, and that said sole comprises contact surfaces (4) for elastic supporting devices (7) included in the ball-of-the- foot binding, said devices being intended for adjusting the angle between the boot and the ski when the ski is raised free of the track.

4. A ski boot as defined in claim 1, c h a r a c t e r i z e d in that said connecting shaft (3) is arranged in said boot (1) and that said attachment means (2) and (2a) are arranged in the ball-of-the-foot binding (9) .

5. A ball-of-the-foot binding (9) for attaching a ski to a boot (1), c h a r a c t e r i z e d in that a connecting shaft (3) included in the binding is located below the ball of the foot, and that said connecting shaft is locked to the boot by means of locking means (2) and (2a) located at said boot in such a manner that it has a possibility to rotate, and that said binding includes adjustable elastic means (7) , by means of which a selectable angle (8) of at least 0 to 30┬░ between the boot and the ski is established via contact surfaces (4) at the boot when the ski is raised free from the track, and that the binding includes a side surface (15) , which functions as a lateral guiding device in co-operation with a supporting ridge (13) at the boot.

6. A ball-of-the-foot binding as disclosed in claim 5, c h a r a c t e r i z e d in that the lateral supporting surfaces (15) of the binding are extended using a separate extension bead (11) which is attached to the ski, which bead matches said supporting ridges (13) arranged in the sole of the boot .