SPORT SHOE SOLE PROVIDED WITH OBSTACLES

Abstract: Sport shoe sole provided with either stationary or replaceable obstacles, and more specifically to the sole of a sport shoe designed for running or jogging. The obstacles are located in the sole construction in the region between the point of support (C) of the ball of the foot and the centre of gravity (P') of the heel. The moment arm (x2) of the foot is shorter than the respective moment arm (x1) with an ordinary sport shoe. This saves energy, and the dynamic resistance of the calf and the Achilles tendon with each step is reduced in comparison to the prior art, so that the running proceeds economically and effectively. The heel platform located behind the centre of gravity (P') of the heel is lowered down, in which case the moment arm (x3) of the heel is eliminated, and the front muscle of the lower leg is released from unnecessary strain.

Description: SPORT SHOE SOLE PROVIDED WITH OBSTACLES The present invention relates to a sport shoe sole provided with obstacles. In the prior art there are known sport shoe sole constructions which are provided all the way from toe to heel with some sort of stationary obstacles, such as grooves which are transversal with respect to the proceeding direction, and/or bulges or various different studs or stud-like members located adjacent to each other, and the heel platform proper. Such sole constructions are not particularly well suited for jogging or running excercises. They cause multiple strain in the legs and feet which may easily become sore. Spikes, studs and other similar obstacles are normally attached to sport shoe soles by means of suitable fastener plates or by screwing them into screw sockets located in the sole. The sole, and consequently the whole shoe, becomes relatively heavy owing to this kind of fastening methods. Moreover, the shoe has to be manufactured in several stages which results in a high price. Spikes or studs provided with a suitable fastener flange can be attached by pushing them into small pockets which are arranged in the shoe sole. The drawback with this type of sport shoe is the special structure of the sole and the resulting demands set for the spikes or the like - for example the necessity to provide a stiff fastening flange. The aforementioned drawbacks can be avoided by employing the sport shoe sole of the present invention, where the sole is provided with either stationary or replaceable obstacles. The invention is characterized by the novel features enlisted in the patent claim 1. The sport shoe sole provided with obstacles, according to the present invention, is particualrly well suited to a running or jogging shoe. The obstacles are positioned within the area between the point of support of the ball of the foot and the centre of gravity of the heel, or at least around the border region of this area in the vicinity of the said points; consequent y, the legs and feet, while running, are not strained to the same extent as before. A preferred embodiment of the sole construction renders the possibility to match the obstacles in suitable locking grooves located in the sole, and the particular grooves employed each time can be individually chosen. After testing, each user can place the obstacles so that the dynamic strain in the calves and in the Achilles tendons is as small as possible while running. The flexibility and attenuation properties of the shoe can also be affected by modifying the nature of the obstacles. Moreover, the obstacles or obstacles belts can easily be changed according to the terrain (gravel road, asphalt), weather conditions (rain, sunshine) or the season, and thus the shoes always have the best possible grip. The obstacles also prevent the shoes from wearing out too quickly. In the following the invention is explained in detail with reference to the appended drawings, where Figure 1 is an illustration of the sport shoe sole of the invention, provided with stationary obstacles, seen in cross-section in the lengthwise direction, Figure 2 is an illustration of the sport shoe sole of the invention, provided with replaceable obstacles, seen in cross-section in the lengthwise direction, Figure 3 is an illustration of the sport shoe sole of Figure 2, seen from below, Figures 4a and 4b are detailed illustrations of two different locking groove arrangements for a sport shoe, as well as of the obstacles matched in the respective grooves, Figure 5 is an illustration of the locking groove and obstacle of figure 4a, seen in partial cross-section along the line A-A. The whole area of the sport shoe sole 1 can be provided with obstacles, such as transversal grooves 2' or corrugations, as is seen in figures 1 and 2. When a person, after putting the sport shoes on, remains standing in attention position, the centre of gravity of the body falls on the vertical line PP ' drawn via the ankle bone (malleolus medialis), wherein P' refers to the centre of gravity of the heel . While walking or running barefooted or with ordinary (spor)shoes, the point of support C of the foot is at the ball of the foot 4, near the toes 5. In figures 1 and 2, the distance between the centre of gravity of the heel and the point of support of the ball of the foot, i.e. the moment arm of the foot, is indicated with the symbol x1. In the sport shoe sole of the invention, the obstacle or group of obstacles 30a, which is positioned between the centre of gravity of the heel P' and the support point of the ba l of the foot C, so that it is advantageousy located 10...25 % nearer to the centre of gravity of the heel with respect to the distance x1 , is formed so that it is at least partly protruding as compared to the rest of the sole which conforms to the form of the sole of the foot. Thus a new point of support C' for the ball of the foot is obtained, and the distance between the centre of gravity P* and the point of support C 1 , i.e. the moment arm of the foot, is reduced to x2. While walking or running barefooted, the moment arm of the foot of a normal-sized person is x1-*--150 mm in average. While employing the sole construction of the invention, the moment arm can be reduced for instance to x2^-'125 mm. This reduces the dynamic strain in the calf and the Achilles tendon about 5-10 kp with each step and consequently helps to save energy, so that an economical and effective running technique can be achieved. In figure 1, the line TM-TM describes the ground surface with respect to the sport shoe in dashes and in speed running. The sole construction of the invention is advantageously suited for realizing a lowered-down heel platform. This is achieved so that the obstacle or group of obstacles 30b, which is located in the immediate vicinity of the centre of gravity P' of the heel, is mainly formed to protrude from the rest of the sole construction, in similar fashion as above, at the point of support C' of the ball of the foot. Now the moment arm x3 between the centre of gravity P' and the heel is eliminated. Consequently the front muscle of the lower leg (musculus tibialis anterior) is released from unnecessary strain and loss of energy. The heel platform does not disturb the step, particularly on ' a downhill track (line AM-AM, figure 1), but now the steps flow fluently to their full length. Simultaneously the workin area of the foot and the calf is extended, and the step becomes longer. Those obstacles that are located at the border region between the centre of gravity P' of the heel and the new point of support C' of the ball of the foot, can also be partly or wholly formed so that they are protruding members with respect to the rest of the sole, i.e. the heel and the toe. These obstacles do not extend further than to the same level as the obstacles 30a, 30b located in the immediate vicinity of the centre of gravity P' and the point of support C' . Of Pϊ Λ ._ iP0 . In figure 2, it is schematically illustrated how, according to a preferred ambodiment of the invention, the sole 1 of a sport shoe is provided with locking grooves 2 positioned transversal1y with respect to the heel-toe line; these locking grooves can be provided with replaceable obstacles 3. The locking grooves 2 may extend over the whole sole, as is seen in figure 2, or the grooves 2 may be closed at the sole edges. In the lengthwise direction of the shoe, every second groove can be an ordinary groove 2', while the rest of the grooves are locking grooves 2. The locking grooves 2 are positioned in the sole in the region between the point of support C of the ball of the foot and the centre of gravity P' of the heel. According to the basic principle of the invention, the point of support C of the ball of the foot can be shifted to a desired point C' by fixing the obstacles 3a to a suitable locking groove 2. In addition to this, the grooves 2 can be made suitably curved, as is illustrated in figure 3: on the side of the ball of the foot, they are made convex in the toe direction, and on the side of the heel they are made concave respectively. The locking groove 2 has a V-shaped cross-section (figure 4a), or respectively it is gradually narrowing towards the inside of the sole (figure 4b), and at the bottom thereof there is arranged a suitable cavity or extension 21 which is parallel to the groove. The stems of the obstacles 3 are formed to match the locking grooves 2 as is shown in figures 4a and 4b, so that they can easily be pressed into the grooves 2 or removed from the grooves 2. The tips 3' of the obstacles 3 can be suitably designed to serve different purposes; they can be for example arrow-heades (figure 4a) and provided with one or two ridges (figure 4b). They can also be provided with reinforcements. The obstacles 3 can be made of the same ' BUK£4 OΛ1PI < WiPO material as the sole, but advantageously they are made of a material harder than the sole material. The obstacles 3 which are matched into the locking groove 2 are advantageously formed of a uniform, flexible belt or a similar arrangement with interconnected adjacent members 31, 32, 33... as is shown in figure 5. By employing the sole construction described above, it is advantegeous to realize the lowered-down heel platform: an obstacle belt 3b is simply matched in the locking groove of the sole, at the spot where the line PP ' , drawn via the ankle bone P and the centre of gravity P', intersects the sole. This operation eliminates the moment arm x3 of the heel . When obstacles and obstacle belts are attached to the transversal grooves 2 or corrugations formed in the sport shoe sole, so that the obstacles can be changed according to the weather, the terrain and/or the season, a decisive influence as regards the grip of the shoe can be achieved. For example, the obstacle belts employed in wintertime may comprise steel tacks at suitable intervals in order to improve the grip while running on icy roads. With a.dense groove system, the shoe is made flexible and light. In order to prevent the runner form sliding sideways, and in order to improve the support required by the shoelacing, the grooves 2, 2' in the sole can be made suitably curved, i.e. arching. In the above specification, the invention has been explained mainly with reference to a few preferred embodiments. It is to be understood that the invention can be modified in many ways without departing from the inventive idea expressed in the patent claims. For example, the stationary obstacles or groups of obstacles 30a, 30b, can be studs or the like which are suitably placed in the sport shoe sole 1.

Claims: PATENT CLAIMS 1. A sport shoe sole provided with obstacles, c h a ¬ r a c t e r i z e d in that the specific obstacle or group of adjacent obstacles (30a, 3a) - which is located between the point of support of the heel (P 1 ) and the centre of gravity of the ball of the foot (C) so that with respect to the distance (x1) between these two points, it is advantageously positioned 10...25 % nearer to the centre of 10 gravity (P 1 ) of the heel - is made at least partly proturuding at least with respect to the sole construction in the toe part of the shoe, so that a new point of support (C 1 ) for the ball of the foot is obtained, and the distance (x2) between the centre of gravity of the heel and the 15 point of support of the ball of the foot is made shorter. 2. The sport shoe sole according to claim 1, c h a r a c¬ t e r i z e d in that the specific obstacle or group of obstacles ' (30a, 3b) which is located in the vicinity of the *20 centre of gravity (P 1 ) of the heel, is formed to be mainly protruding with respect to the shoe sole surrounding the centre of gravity (P') of the heel, so that the moment arm (x3) between the centere of gravity (P') and the heel (6) is eliminated. 25 3. The sport shoe sole according to claim 1 or 2, c h a¬ r a c t e r i z e d in that the specific obstacles which are located within the region between the centre of gravity (P 1 ) of the heel and the new point of support (C 1 ) of the 30 ball of the foot are at formed at least partly protruding with respect to the sole construction in the toe part and in the heel . 35 O PI WiPδ " 4. The sport shoe sole according to claim 1 , 2 or , c h a r a c t e r i z e d in that the protruding obstacles (30a, 3a; 30b, 3b) are positioned in the sole (1) in an arched fashion with respect to the lengthwise direction of the shoe. 5. The sport shoe sole according to any of the preceding claims, c h a r a c t e r i z e d in that the sole (1) of the sport shoe is provided with transversal locking grooves (2) advantageous y extending over the sole, into which grooves (2) the obstacles (3) can be replaceably attached, and that the locking grooves (2) are located in the sole construction in the region between the centre of gravity (P ! ) of the heel and the new point of support (C) of the ball of the foot. 6. The sport shoe sole according to claim 5, c h a r a c¬ t e r i z e d in that every second groove in the lengthwise direction of the shoe is an ordinary groove (2') and the rest of the sole grooves are locking grooves (2). 7. The sport shoe sole according to claim 5 or 6, c h a r a c t e r i z e d in that the cross-section of the locking groove (2) is narrowed inwards, and that the bottom part of the groove (2) is provided with an extension (21). S. The sport shoe sole according to claim 5, 6 or 7, c h a r a c t e r i z e d in that the obstacles (3) which are matched in the locking groove (2) are formed of a uniform belt or a similar arrangement of interconnected members (31 , 32... ) . 9. The sport shoe sole according to claim 8, c h a r a c¬ t e r i z e d in that the tip (3') of the obstacle (3) has an arrow-shaped cross-section in the lengthwise direction of the sole construction (figure 4a). 10. The sport shoe sole according to claim 8, c h a ¬ r a c t e r i z e d in that the cross-section of the tip (3') of the obstacle (3) in the lengthwise direction of the sole is arrow-shaped and contains two ridges (figure 4b).

Inventors: KOSKELA TAUNO, KOSKELA, TAUNO
Applicants: KOSKELA TAUNO, KOSKELA, TAUNO
Application year: 1984
Main classification: A43B13
IPC codes: A43B13