The object of the present invention is a sport shoe spike, meant to be attached either permanently or removably into the sole construction of the shoe and comprising a plate-like fastener flange as well as at least one spike located roughly at right angles to the flange surface.

In the previous art are known several different sport shoe spikes. As examples can be mentioned the spikes presented in the Finnish Patent Publications n:o 24317 and 34 992. The former publication introduces a sport shoe spike which has a triangular cross-section and is attached to the support plate by riveting or by screwing. The spike is placed into the shoe- sole, vhere one edge of the three-edged spike points forward, and the even edge backward. Moreover, the spike is designed in such a fashion that the back surface of the spike forms an angle of more than 90° with the support plate when seen from the side. Thus the spike can be lifted from the track with

'* lesser effort.

The Finnish Patent Publication n:o 34 992 presents a spike which is otherwise similar to the above described spike, but 'now the back surface of the spike is convex, whereas its front edge is straight.

The most prominent drawbacks of the above described, previously known spikes are their expensiveness and heaviness. Their high price is due to the fact that the spike and the support plate are normally manufactured separately and then screwed together. This construction also causes the weight of the spike to increase considerably.

The above explained drawbacks can be avoided by using a spike according to the invention, characterized by the "features pre¬ sented in the Patent Claim 1.

O PI /., WIPO -*,

Among the advantages of the spike and its production method ac¬ cording to the present invention can be mentioned the fact that the shoe becomes essentially lighter. It is possible to pro¬ duce the spike according to the invention essentially cheaper than the spikes known in the previous art. Moreover, by using the spike according to the invention it is possible to achieve the same advantages as when employing other known, developed spikes. In other words, at the moment of pushing off the form of the spike urges the foot forward, thus lengthening the step and adding to the running speed. Because of its sharp front edge the spike of the invention is easily turned forward and can thus be lifted from the track with little effort.

In the following the invention is described in detail with refe¬ rence to the attached drawings. Figure 1 is a sche atical perspective view of one preferred embodiment of the invention. Figure 2 illustrates how the spikes according to the invention are placed in the sport shoe sole. Figure 3 shows an elementary form of the member of which the spike of the invention is produced. Figure 4 shows an intermediate phase in the production of the spike according to the invention. Figure 5 represents another preferred embodiment of the invention in side elevation viewr Figure 6 illustrates the cross-section VI-VI of the Figure 5.

The spike presented in Figure 1 is made out of metal plate. It comprises the fastener flange 1 and the spike 2. In this embodi¬ ment the fastener flange consists of two parts 3 and 4, which are held together by the spike 2. The spike 2 comprises a fairly sharp front edge 5, which is roughly at right angles to the fas¬ tener flange 1. At the top of the front edge 5 is the sharp peak 6, wherefrom the edges 7, 8 forming the back surface of: the spike continue backwards in ¹ a slanted fashion. Thus the cross-section of the spike has the form of the letter V. Owing to its form the spike is considerably solid in every direction, and in particular it is capable of receiving the force created when pushing off, the said force being directed towards the back _____ ______

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edges. The forces pushing towards other directions are, accor¬ ding to investigations, remarkably weaker. Owing to the sharp¬ ness of the front edge 6 and the slanted form of the back edges 7, 8 the spike can be lifted off the track with lesser effort.

Figure 2 shows the sport shoe sole seen from below. Spikes according to the invention are attached to the sole in two sections 21 and 22. It is advantageous to place two spikes in the section 21 located under the toes, and three spikes in the section 22 located under the ball of the foot. The spikes 20 are preferably fixed removably, so that the sharp front edge of the spikes points towards the shoetop.

Figures 3 and 4 illustrate the production of a spike according to the invention. The spike according to the invention is pre¬ ferably manufactured of metal plate, out of which metal plate is punched the elementary spike 31. Thereafter the elementary spike is bent roughly 180° in the direction of the lengthwise axis of the spike along the dotted line 32, as is shown by the arrows 33. After the bending, the elementary spike seen from the front looks like Figure 4. The following phase in the production is to form the fastener flange to the spike by bending the parts 43 and 44 in the direction of the arrows. The bending lines are marked in Figure 3 by the dotted line 34.

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Fibures 5 and 6 present another advantageous application of the invention. As the spike of Figure 1, also this spike comprises a fastener flange 51, which consists of two parts 53 and 54. The spike proper 52, which has the cross-section in the form of the letter V, comprises the sharp front edge 55. The front edge 55 is ended at the sharp peak 56, which can also be slightly rounded depending on the material where the spike is meant to be used. From the peak 56 backwards the back edges 57 and 58 continue down in a slanted direction.

As can be seen from Figures 5 and 6, the method of production is slightly different from the schematical application presented in Figures 7 and 4. The main difference lies in the fact that now additional modelling work is employed and thus, among other

things, the front edge of the peak can be made sharper. Simi¬ larly, the flange part is pressed to be slightly more arched and thinner by the edges. Naturally other methods, for example abrading, can be employed in order to achieve the same results.

The invention has above been explained by referring to only a few preferred embodiments, but the intention has by no means been to limit the invention within the above described examples. Thus the spike according to the invention can remarkably differ by its looks from the spikes illustrated in the drawings.