FR3086511A1 - INSTRUMENTED STUDDED SHOE - Google Patents

Abstract

The present invention relates to a stud (3) comprising: - a base for fixing to a sole (2) of studded shoes, this base coming to bear against the underside of the sole, - a stud body, defining at least partially the external surface, - a connecting part connecting the body to the base, so as to allow the body to move relative to the base under the effect of a force exerted on the body of the crampon by the wearer of the shoe, - at least one sensor sensitive to a movement of said body and / or to a deformation of the connecting part during this movement.

Description

INSTRUMENTED STUDDED SHOE

The present invention relates to the measurement of the forces exerted on a studded shoe.

A problem which arises, when the measurements of the forces are carried out using instrumented soles, is often the invasive nature of the measurement, which modifies the properties of the shoe, for example the stiffness or the thickness of the sole, the space available for the foot or its position. This then makes the shoe difficult to use on the ground for the usual game. In addition, existing instrumented shoes do not always measure stresses in all directions.

US Pat. No. 6,182,381 describes a baseball shoe sole equipped with effort measurement plates.

Application US 2007/0261271 A1 describes a shoe sole with studs provided with deformable studs. The sole has an electronic circuit which includes a sensor such as an accelerometer, and which is arranged to control actuators present within the crampons, making it possible to modify their shape.

The article DEVELOPMENT OF A METHOD FOR MEASURING HORIZONTAL FORCES IN SOCCER BOOTS STUDS DURING SKILLS PERFORMANCE A.C. Garcia et al. Institute of Biomechanics of Valencia. Spain August 1999 In Forth Symposium on Footwear Biomechanics describes an instrumented spike comprising an axis on which is screwed an external part constituting the outer casing of the spike, with interposition of a foam gasket between the underside of the sole and the top edge of this piece. Four strain gauges are mounted on the axis on which the part constituting the crampon envelope is screwed, and connected to a processing circuit. The axle is held on the inner side of the sole by a nut. The joint must be compressed to ensure its function, with the disadvantage of generating static stresses which hamper the movement of the external part and affect the accuracy of the measurement. The compression forces along the axis of the clamp are not measured.

There is a need to improve the knowledge of mechanical stresses reflecting the interaction between an athlete's shoes and the field, and in particular to have an instrumented shoe capable of accurately measuring the stresses exerted on a crampon, in particular in all directions.

The invention meets this need with a crampon comprising:

a base for fixing to a shoe sole with spikes, this base coming to apply against the underside of the sole, a spike body, at least partially defining the external surface, a connecting part connecting the body to the base so as to allow the body to move relative to the base under the effect of a force exerted on the body of the crampon by the wearer of the shoe, at least one sensor sensitive to a movement of said body and / or to a deformation of the connecting part during this movement.

The invention makes it possible to measure at least one mechanical stress exerted on the crampon during the evolution of the sportsman who wears the shoe, without modifying the feeling or the comfort thereof.

Knowledge of this constraint can be used to optimize the shape of the studs. It can also be used to monitor the athlete’s physical condition.

The presence of the base ensures the fixing of the clamp without the need to provide a seal as in the aforementioned prior art.

The invention makes it possible to measure the forces transmitted between an athlete's shoes and the ground at the attachment points that constitute the studs, in three directions if desired, namely a direction coincident with the axis of each crampon and two directions perpendicular to this axis. This makes it possible to go back to the resulting force transmitted by the attachment point as well as its direction. This solution is not invasive and the invention makes it possible, respecting a standard screw pitch (for example that of the World Rugby Regulation 12 BS 6366: 2O11 + A1: 2017 September 2011 Specification for studs for rugby football boots or that of a brand of shoes) for fixing the crampon to the sole to be adapted to any shoe with cleats.

The invention can implement a data acquisition system which can be internal or external to the shoe, or even miniaturized and directly integrated into the crampon.

The invention makes it possible, if desired, to use exactly the same dimensions, external shape and grip characteristics as those of the studs commonly used, not modifying the feeling or the comfort of the user. The structure of a crampon according to the invention, namely with two physically distinct parts, including an internal part dedicated to the measurement and an external part in contact with the ground, allows the user to modify the grip characteristics on the terrain by changing the external part to adapt to the conditions on the ground without modifying the measurement part.

Thus, preferably, the body of the stud is detachably fixed on the connecting part, in particular by being screwed thereon. This can make it possible to easily mount various forms of crampon body, and to study the impact of this on the forces encountered during the movement of the wearer of the shoe. This can also make it possible, as mentioned above, to choose the shape of the crampon that best suits a type of terrain or game, for example.

Preferably, the sensor is placed on the connecting part and reacts to a deformation of the latter.

The crampon may include three sensors arranged so as to measure the stresses exerted along the x, y and z axes of an orthonormal reference associated with the crampon, the z axis being coincident with the longitudinal axis W of the crampon. The connecting part being elongated along the z axis, the sensors intended to measure the stresses along the x and y axes are preferably constituted by strain gauges arranged on the connecting part so as to be deformed by bending of the connecting part, said gauges being preferably closer to the end of the connecting part connected to the base than to the end of the connecting part connected to the body of the stud. This makes it possible to benefit, for a given effort, from a greater amplitude of deformation of the connecting part, and therefore from a better sensitivity of the gauges.

The sensor intended to measure the stress along the z axis can be placed on the connection part by being closer to the end of the latter connected to said body than to the end connected to the base.

Preferably, the base has a threaded hollow axis screwed onto the sole. The hollow axis allows the passage of a connection between the sensor or sensors present in the crampon and an acquisition circuit which is for example integrated into the sole, for example in its heel. The hollow axis can thus be traversed by at least one electric cable connected to said sensor.

Preferably, the connecting part comprises a cylindrical part on which the sensor or sensors are mounted. This cylindrical part can be of circular cross section or not, for example polygonal, preferably square.

The connecting part may include a portion forming a beam, made of steel. This portion forming a beam can be constituted by the aforementioned cylindrical part.

The base may be wider at its contact surface with the sole than the body at its upper edge. Preferably, the base has an outer surface which is substantially in line with the outer surface of the body. In particular, the edge formed at the junction between the lateral surface of the base and the underside thereof facing the body may be of diameter greater than that of the upper edge of the body.

In an exemplary implementation, the stud comprises an acquisition circuit connected to the sensor (s) and preferably a memory for recording data coming from the sensor (s) and / or a wireless transmission system of these data to a remote computer system. This allows all the electronics to be concentrated in the crampon, which can then be attached to a normal shoe without electronics.

The invention also relates to a studded shoe, comprising at least one stud according to the invention, as defined above. The shoe may include, as mentioned above, an acquisition circuit connected to said sensor, in particular by a cable. The acquisition circuit can be arranged in the sole.

The acquisition circuit may include a memory for recording data from said sensor and / or a system for wireless transmission of this data to a remote computer system.

The shoe can be a shoe for a football or rugby player, among others, the invention applying to any studded shoe in general.

The shoe may have only one stud according to the invention, or alternatively several studs, preferably at the front and at the rear. Preferably, all of the studs of the shoe are connected studs according to the invention.

The subject of the invention is also an assembly comprising a shoe as defined above and at least one additional spike body, which can be substituted for that present on the connecting part and having for example a surface condition and / or a different shape and / or different material.

The user can thus have at his disposal a range of spike bodies and choose the one best suited to the state or nature of the terrain for example, in particular natural, synthetic or hybrid terrain, dry or wet, or to climatic conditions. .

The subject of the invention is also a method of acquiring data representative of at least one mechanical stress exerted on the studs of a studded shoe when the shoe is worn by a person, in which data representative of said stress are acquired using a crampon as defined above.

For example, the data is compared to benchmark data and information related to a player's performance status is generated.

During a match, one can decide on a change of player or type of crampon, using this information.

This can be done, for example, to reduce the risk of injury.

The subject of the invention is also a method of configuring a studded shoe, in which a data acquisition is carried out using the aforementioned method, this data is analyzed and a form of stud is selected. among several depending on the data thus analyzed.

Another subject of the invention, according to another of its aspects, independently or in combination with the above, is a stud comprising a fixing part to be fixed to the sole, a body defining at least partially the external surface of the stud, in contact with the ground, and a connecting part connecting the body to the fixing part, at least two sensors for measuring the stresses in x and y directions of a reference point associated with the crampon, the z axis being coincident with the longitudinal axis of the crampon, and a sensor for measuring the compression stresses along the z axis, this sensor being closer to the distal end of the crampon, that is to say the one farthest from the sole, than the two other sensors. This allows, as indicated above, to have good measurement accuracy. Such a crampon may moreover exhibit all or part of the characteristics defined above.

The invention will be better understood on reading the detailed description which follows, of an example of non-limiting implementation thereof, and on examining the appended drawing, in which:

FIG. 1 shows in side view an example of a shoe according to the invention, FIG. 2 illustrates a view from below of the stresses applied on the crampons, FIG. 3 represents in isolation a crampon according to the invention, FIG. 4 is a schematic axial section of the spike of FIG. 3, and FIG. 5 is a diagram of an example of a measurement path.

The shoe 1 shown in FIGS. 1 and 2 comprises a sole 2 fitted with studs 3, at least one of which is produced in accordance with the invention. In Figures 1 and 2 the studs 3 are shown in a simplified form.

This shoe 1 is for example intended for the practice of football or rugby.

During the evolution of the person wearing the shoe 1, the crampons 3 are subjected to mechanical stresses C, which can decompose into a shear stress and a compression stress.

A crampon 3 according to the invention is shown in isolation in FIGS. 3 and 4.

FIG. 3 shows an orthonormal reference frame xyz associated with the stud 3, the axis z being coincident with the longitudinal axis W of the stud 3.

The crampon 3 comprises a base 10, for example metallic, having in the upper part a hollow axis 11 threaded with axis W, arranged to be screwed into a corresponding housing provided on the sole 2.

Preferably, the outside diameter of the axis 11 and the thread pitch are chosen so as to be able to equip with a crampon according to the invention a standard sole of an existing shoe.

The base 10 can widen towards the sole 2, as illustrated, and have an upper face 12 which is flat and perpendicular to the axis Z, to which the axis 11 is connected, and a lateral surface 13 of rounded shape, preferably symmetrical in revolution, for example in the general shape of a torus portion.

The base 10 may have a stepped lower face 14, with a central part 15 to which a connecting part 20 is connected.

The latter has an elongated shape along the axis Z, with a cylindrical part 21 of axis W provided in the lower part with a flange 22, the latter being extended downwards by a solid threaded axis 23, of smaller outside diameter than the cylindrical part 21. The cylindrical part 21 may be axially symmetrical, and preferably of square section. The diameter of the cylindrical part is in this case that of the circle which passes through the edges.

The connecting part 20 and the base 10 can be made monolithically from steel, in particular from stainless steel.

The stud 3 has a body 30 which is fixed to the connecting part 20.

In the example considered, the body 30 has a lower part 31, for example planar and perpendicular to the axis W, which is extended at its periphery by a conical side wall 32 widening upwards.

The upper end 33 of the body 30 is located at a non-zero distance d from the lower face 14, and also surrounds the central part 15 at a non-zero distance j.

The axial clearance d existing between the lower face 14 and the upper end 33 is for example between 0.1 and 1.2 mm.

The small space existing between the upper edge 33 and the lower face 14 limits the penetration of earth or other elements found on the ground in the space inside the body 30, despite the absence of a seal. Where appropriate, a seal is provided to close this space between the body 30 and the underside 14.

The base 10 may be wider at its contact surface with the sole than the body 30 at its upper edge 33.

Preferably, the lateral surface 13 is substantially in line with the exterior surface of the body. In particular, the edge formed at the junction between the lateral surface 13 of the base and the lower face 14 thereof turned towards the body may be of diameter greater than that of the upper edge 33 of the body 30.

The lower part 31 is crossed by a threaded hole 36 of axis W, into which the threaded axis 23 is screwed, and the lower end 23a of the latter comes for example flush with the lower face 35 of the body 30 or slightly set back from it.

The body 30 is for example made of stainless steel.

The fixing by screwing of the body 30 on the axis 23 makes it possible to mount on the crampon a body 30 of chosen shape, selected from a range of pre-existing bodies 30, of different shapes. By way of example, FIG. 1 shows an additional body 30 ′, the surface finish of which is different, for example rough while that of the body 30 in place is smooth.

The range of different bodies that can be fitted to a crampon may generally include at least two bodies which differ by at least one from:

their length, their taper, their surface state, for example smooth or rough, their constituent material, for example metallic or synthetic, their shape, for example of revolution or not.

The connecting part 20 constitutes an internal part of the stud which is the instrumented part and the body 30 constitutes an external part whose only link with the internal part is at the level of the threaded axis 23, which is the only link between these two rooms. Thus the forces transmitted from the ground to the shoe pass through the connecting part 20.

The connecting part 20 constitutes a beam which deforms slightly under stress. Depending on the direction and the norm of the force, the deformations of the beam are not identical. The measurement of these deformations makes it possible to go back to the force C exerted on the stud. For example, the connecting part 20 is dimensioned so that the maximum deflection for a stress equivalent to a weight of 100 kg, exerted on the crampon along x or y, results in an deflection between 100 and 500 microns, preferably of around 300 microns.

Preferably, the connecting part 20 is made of steel in order to resist the stress, with a section small enough to have measurable deformations.

The spike 3 is equipped with sensors providing information on the movement of the body 30 relative to the base 10 under the effect of the stresses exerted on the spike 3 during the movement of the carrier.

Preferably, as illustrated, sensors are mounted on the connecting part 20 to measure its deformations, which are representative of the movements of the body 30 relative to the base.

In the example illustrated, there are thus three sensors on the connection part so as to measure the stresses exerted along the x, y and z axes.

The sensors 40 intended to measure the stresses along the x and y axes are constituted by strain gauges arranged on the connection part 20 so as to be deformed by bending of the connection part, in a location closer to the upper end of the connecting part connected to the base than of the lower end of the connecting part connected to the body of the stud. This gives an amplitude of bending deformation of the connecting part 20 greater than what it is at the lower end thereof.

The sensor 41 intended to measure the stress along the axis z is disposed on the connecting part 20 being closer to the lower end thereof than to its upper end.

The sensors 40 and 41 can be bonded to the surface of the cylindrical part 21, on respective faces of the latter.

The sensors 40 and 41 are preferably surrounded by a sheath or encapsulation of a material which seals against water, with respect to possible penetrations of liquid by the play existing between the upper edge 33 and the base 10.

The choice of the section and the length of the connecting part 20 is made according to the characteristics and details of the gauges used.

For example, the length l of the connecting part 20 measured along the cylindrical part 21 between the shoulder at the base of the flange 22 and that at the base of the central part 15 is between 6 and 14 mm and the cross section of the cylindrical part is for example between 10 and 30 mm ² for a connecting part made of steel. The cylindrical part 21 can be of square section, which can facilitate the mounting of the sensors, on the flat faces of the latter.

Preferably, three gauge half bridges are used, one for the measurement along the x axis, one for the measurement along the y axis and a last for the measurement along the z axis.

The tangential forces along the x axis are obtained thanks to a half bridge of gauges mounted as an inverter, where the gauges replace the resistors Ri and R2 in the Wheatstone bridge illustrated in FIG. 5.

It is the same for the measurement of the forces along the y axis, the two gauges used being offset by 90 ° relative to the gauges used for the measurement of the stresses exerted on the crampon along the x axis.

The normal force, that is to say along the z axis, is measured via a half right gauge bridge, where four gauges replace the resistors Ri and R3 in the Wheatstone bridge 114 of FIG. 5, so as to measure compression.

The four gauges are placed on the lower part of the cylindrical part 21, where the flexion is the weakest, to have sufficient precision on the compression measurement. Two gauges are connected together electrically in series without inverting them to replace the resistor Ri and the same is done with the other two to replace the resistor R3. In a variant not illustrated, only two gauges are used.

The bridge is powered by a generator G, as illustrated. The signals from the bridge can, for each measurement channel, be amplified at 110, then converted into digital form at 111, and processed by a microcontroller at 112, for example of the ESP8286 type or the like, having a wireless connection, for example Wifi, allowing useful information to be transmitted remotely.

In the example considered, there are thus four wires for each bridge, namely two for the power supply of the bridge and two for the feedback of information to the amplifier.

These electrical wires pass through a hole 18 made in the base 10, and through a central passage 19 passing through the axis 11 and into which the hole 18 opens.

The wires then extend to the processing circuit 150 present in a housing in the sole, for example located at the heel. The sole 2 is for example made from a Wiz Wedge brand sole, already having a housing in the heel to accommodate the circuit 150.

The data collected by the circuit 150 can be sent by Wifi or by any other means of wireless communication adapted to a remote receiver 200 such as a computer or other capable of carrying out the analysis, for example mobile phone or tablet, as illustrated.

If necessary, a memory card is placed in the shoe to record the information.

Yet another solution is to embed all of the data acquisition technology directly into each stud. In this case, a processing circuit arranged in the sole is no longer necessary.

In another variant, the studs 3 communicate wirelessly with the processing circuit 150.

The information sent from the boot can be analyzed, either in real time or a posteriori, by software allowing calculation of the forces exerted on each stud 3 as a function of the measured constraints.

This software can display the results of this analysis, for example in the form of a map of the forces between the shoe and the ground at a given time.

It is possible to analyze the results of the measurements according to the phases of play, for example straight line racing, framing-overflow, reception of jump and presses in melee, and to compare them with reference values, so as to achieve performance monitoring and / or being able to determine the player's state of fatigue and / or risk of injury.

The invention is not limited to the example illustrated in the figures.

For example, the stresses exerted on the crampon can still be measured in another way, by having sensors sensitive to the distance separating the upper edge of the body 30 and the base 10.

Claims (20)

1. Crampon (3) comprising: a base (10) for fixing to a sole (2) of studded shoe, this base coming to bear against the underside of the sole, a body (30) of stud, defining at least partially the external surface, a part link (20) connecting the body to the base, so as to allow the body to move relative to the base under the effect of a force exerted on the body of the crampon by the wearer of the shoe, at least a sensor (40; 41) sensitive to a movement of said body and / or to a deformation of the connecting part during this movement. 2. Crampon according to claim 1, the body (30) being detachably fixed on the connecting part (20), in particular by being screwed thereon. 3. Cleat according to one of claims 1 and 2, the sensor (s) (40; 41) being disposed on the connecting part (20) and reacting to a deformation thereof. 4. Cleat according to any one of the preceding claims, comprising three sensors (40, 41) arranged so as to measure the stresses exerted along the x, y and z axes of an orthonormal reference associated with the crampon, the z axis being coincides with the longitudinal axis (W) of the stud. 5. Cleat according to claim 4, the connecting part (20) being elongated along the z axis, the sensors (40) intended to measure the stresses along the x and y axes being constituted by strain gauges arranged on the connecting part so as to be deformed by bending of the connecting part. 6. Cleat according to claim 5, said gauges (40) being closer to the end of the connecting part connected to the base (10) than to the end of the connecting part connected to the body (30) of the crampon. 7. Cleat according to any one of claims 4 to 6, the sensor (41) intended to measure the stress along the z axis being disposed on the connecting part being closer to the end of the latter connected to said body (30) only from the end connected to the base (10). 8. Clamp according to any one of the preceding claims, the connecting part comprising a cylindrical part (21), in particular of square section, on which the sensor (s) (40; 41) are mounted. 9. Cleat according to any one of the preceding claims, the connecting part (20) comprising a portion (21) forming a beam, made of steel. 10. Cleat according to any one of the preceding claims, the base (10) comprising a threaded hollow axis (11), screwed onto the sole. 11. Cleat according to claim 10, the hollow axis (11) being traversed by at least one electric cable connected to said sensor. 12. Cleat according to any one of the preceding claims, comprising an acquisition circuit connected to the sensor (s) and preferably a memory for recording data coming from the sensor (s) and / or a wireless transmission system. of this data to a remote computer system (200). 13. Shoe (1) with studs, comprising at least one stud (3) as defined in any one of the preceding claims. 14. Shoe according to claim 13, comprising a circuit (150) of acquisition connected to (x) sensor (s) (40, 41). 15. Shoe according to one of claims 13 and 14, the acquisition circuit (150) being arranged in the sole (2). 16. Shoe according to any one of claims 13 to 15, the acquisition circuit (150) comprising a memory for recording data from the sensor or sensors and / or a system for wireless transmission of this data to a computer system remote (200). 17. Shoe according to any one of claims 13 to 16, being a shoe for a football or rugby player. 18. An assembly comprising a shoe as defined in any one of claims 12 to 16 and at least one body (30 ') of additional stud which can be substituted for that (30) present on the connecting part and having a state of surface and / or a different shape and / or a different material. 19. Method for acquiring data representative of at least one mechanical stress (C) exerted on the studs (3) of a studded shoe when the shoe is worn by a person, in which data representative of said stress are acquired using a crampon as defined in any one of claims 1 to 11. 20. Method for configuring a studded shoe, in which a data acquisition is carried out using the method according to the preceding claim. we analyze this data and we select a form of crampon among several functions of the data thus analyzed.