EP1820544A1

EP1820544A1 - Cross-country ski pole

Info

Publication number: EP1820544A1
Application number: EP07396001A
Authority: EP
Inventors: Harri Aaltonen; Pekka Vähäsöyrinki
Original assignee: Procomposite Oy
Current assignee: Procomposite Oy
Priority date: 2006-02-06
Filing date: 2007-02-05
Publication date: 2007-08-22
Also published as: FIU20060057U0; FI7078U1

Abstract

A cross-country ski pole comprised of pole tube (1), grip (2), hand strap (3) and snow ring (4) fixed to the end of the pole tube. The pole tube (1) is formed of one or more parts and made bent at least in one plane, which bent shape is by means of the pole tube structure arranged to its bents shape in unstressed state, and also to bent shape because, thanks to its pole tube structure, it returns from stressed state, with other words, from steeper bent state, while the stress that has bent the pole tube is decreasing.

Description

The invention relates to a cross-country ski pole comprised of a pole tube, a grip, a hand strap and a snow ring fixed in the end of the pole tube.
Previously known are cross-country ski poles, where the axial direction of the grip part differs from the direction of the pole tube on the bases of the forward bent shape of the grip part. As an example of a such one is Finnish Design registration no. 11938 . Furthermore, known is the achievement of a corresponding direction difference by means of a corner piece, by means of which the grip is fixed to the pole tube. A pole tube is also known, in which on a certain spot a change of direction has been made by means of a corner piece or as bending of a tube. As example of these latter ones is Finnish Design registration no. 23470 .
In above presented pole structures the position of the hand on the grip part is made better, when the direction is bent a little towards the direction of the motion away from the pole direction. The impact is felt during pushing.
In above presented solutions the pole is straight or it has straigt parts and the pole tube is inflexible during pushing. With these solutions in the pushing stage the benefit is reached only thanks to the better position of the hand.
Due to the pole tube according to the invention an additional factor has been achieved in the pushing stage to secure that the pushing stage gets fully utilized. The cross-country pole according to the invention is characterized in that the pole tube is formed of one or more parts and it is made bent at least in one plane, which bent shape is by means of the pole tube structure arranged as bent shape in its unstressed state and also as bent shape, to which, thanks to its pole tube structure, it returns from stressed state, in other words from steeper state, while pole stress of tube bending decreases.
The advantage of a cross-country ski pole according to the invention is that the pole tube binds energy in the initial stage and in the middle stage of the push and releases it during the final stage, whereby one is not necessarily anymore able to do a sufficient push. The skier's up/down motion reduces. In the initial stage of push the skier pushes the pole mainly vertically, whereby in this direction energy is stored into to the pole. In the final stage of the push the direction of the pole is already leaned closer to the direction of the skier's motion. The pole energy is freed in the final stage of push and pushes the skier foreward. By means of the invention the the vertical force produced by the skier is changed to forward-pushing horizontal force. The efficiency of the pushing stage improves, when the strengh of skier directed on the push does not tend to lift the skier up from the track as much as push motions done by means of previous poles.
The structure of pole works as a spring reducing the peak of force that arises, when the pole hits the ground and which arises with a straigth pole and is with a straigth pole relatively ineffective.
In the following the invention is disclosed with reference to the enclosed drawing, where

Figure 1: shows the ski pole according to the invention in state of rest and bent because of the push.
Figure 2: shows the ski pole according to the invention in state of rest and bent because of the push on the part of two bent areas in different direction.
Figure 3: shows the ski pole according to the invention in state of rest and bent because of the push over its whole length.

Figure 1 shows a cross-country ski pole formed of pole tube 1, grip 2, hand strap 3 and snow ring part 4 fixed in the pole tube lower end. The pole tube is pre-bent, whereby it is in the state of rest and already essentially deviating from the straigth line. Due to this directions A and B of grip 2 and snow ring part 4 deviate from each other. The pole is so presented that the skiing direction is to the left. Thus the grip part 2 is directed slightly forward observed from the pole's state of rest, because of the pole tube bending and also because of the shape of the grip part 2. In the right side figure, because of push stress, the pole has got more bent especially on part L. The pole has also shortened a distance of s. Additional bending binds energy and the pole strives to release the energy from the grip 2, when the push force caused by the skier against snow ring 4 decreases. The pushing force decreases for many reasons in the final stage of pushing, and the pole straightens to its state of rest and releases its energy in the form of push force. The release of energy is useful the more the skier has leaned the pole foward at the moment of release.
The pole of figure 1 can in one embodiment be so made that part L is a separate pre-bent part connected to a suitable place on pole tube 1. Thus the part L can be made of differrent materials with respect to the other part of the pole tube.
Figure 2 shows another pole in state of rest, which has two parts L1 and L2, in which a pre-bent part, shaped and arosed by manufacture, is visible. On pushing both parts get more bent in their own directions, as shown in the adjacent figure, and in the final stage of push the bendings straighten and the pole releases the energy it has bound.
Figure 3 shows a pole the pole tube of which is pre-bent essentially over the whole length L. The adjacent figure shows the pole in bent state on pushing.
Pole tube 1 is made of composite material or so that other reinforcements, as metal, are added to it. The pole tube 1 can also be completely of metal. Anyhow, it is important that the pole tube bends because of the push and that greater bending requires greater push force from the skier. Thus it is advantageous that the bending of the pole meets a limit by certain pushing force, for instance 300-500 N. Of course, the pole tube must endure this force limit thousands of times in loading tests. The structure of pole can be made especially to endure bending in a certain direction. In this case the direction is the same in which pre-bending is made. The firmness of the pole can be affected by means of the numbers of strengthening fibers or corresponding directions of structural members or by means of stress-strain qualities. One or more of the above structural qualities are arranged to resist additional bending, when the pole bending steepens.
Tthe invention is not restricted to the enclosed embodiment but can be modified in many ways within the limits of the idea presented in the claims of the invention.

Claims

A cross-country ski pole comprised of pole tube (1), grip (2), hand strap (3) and snow ring (4) fixed to the end of the pole tube, chacterized in that the pole tube (1) is formed of one or more parts and made bent at least in one plane, which bent shape is by means of the pole tube structure arranged to its bents shape in unstressed state, and to bent shape also because, thanks to its pole tube structure, it returns from stressed state, with other words, from steeper bent state, while the stress that has bent the pole tube is decreasing.
A. cross-country ski pole according to claim 1 characterized in that on the pole tube (1) a separate bent part is fixed, the structure of which is made bending and returning under stress.
A cross-country ski pole according to claim 1 characterized in that pole tube (1) structure is by means of the numbers of strengthening fibers or of corresponding directions, or by means of stress-strain qualities arranged to resist additional bending, when the bending is getting steeper.
A. cross-country ski pole according to claim 1 characterized in that the axial directions A, B of the pole lower and upper part deviate from each other in the unstressed state of the pole.
A cross-country ski pole according to claim 1 characterized in that the structure of the bent part (L),(L1),(L2) of the pole tube (1) consists of a combination of different materials