WO2019123038A1

WO2019123038A1 - Sensorized device for fastening climbing holds provided with a triaxial load cell

Info

Publication number: WO2019123038A1
Application number: PCT/IB2018/058525
Authority: WO
Inventors: Raffaella SESANA; Daniela MAFFIODO; Andrea Andreoli; Romeo CASESA; Luis Alejandro ESTRADA DIAZ; Silvia MILAN; Andrea Zanotti; Alessandro Colombo; Alessandro BERTAGNA; Juan Miguel COLS MATHEUS; Ramon MAJ
Original assignee: Politecnico Di Torino; Politecnico Di Milano
Priority date: 2017-12-19
Filing date: 2018-10-31
Publication date: 2019-06-27

Abstract

The invention relates to a device for fastening holds (10) for sport climbing equipped with a triaxial load cell (2) comprising two first pairs of strain gauges (A1, A2; A3, A4) and two second pairs of strain gauges (B1, B2; B3, B4) positioned respectively in a first plane (z1) and in a second plane (z2), in which the two planes (z1; Z2) are distinct from each other, are parallel to each other and are parallel to the plane costituted by a climbing wall (6) on which climbing holds are installed, each provided with the device for fastening holds (10); the device for fastening holds (10) further comprises a bushing (4) comprising two third pairs of strain gauges (A5, A6; B5, B6) positioned in a third plane (z3) parallel to the first plane (zl), the second plane (Z2) and the climbing wall (6); all the pairs of strain gauges have strain gauges arranged in parallel to the main axis of the hold fastening device (10); defined a cartesian reference system (x, y, z) for the device for fastening holds (10), in which the x and y axes are contained in the plane formed by the climbing wall (6) and are mutually perpendicular, with x parallel to the ground on which the climbing wall (6) rests, and in which the z axis is perpendicular to the plane of the climbing wall (6) and parallel to the plane of the climbing wall (6) and parallel to the main axis of the hold (10), the hold device (10) detects measurements of deformation in the x, y and z directions, from which the components of force fx Fy and Fz are derived in the corresponding directions x, y and z; the hold device (10) can also comprise an interface (12) and a computer (14) for the force data detected. The present invention finds preferred and advantageous applications in sport climbing training and competitions and also in functional recovery and psychomotricity.

Description

"Sensorized device for fastening climbing holds provided with a triaxial load cell"

DESCRIPTION

TECHNICAL FIELD

The present invention relates generally to the field of sports equipment, and more specifically to the field of climbing.

The present invention has the object to provide a device for fastening climbing holds for sport climbing provided with a triaxial load cell.

Among other possible areas of application of the present invention, in addition to training and competitions of sport climbing, there are functional recovery and psychomotricity.

STATE OF THE ART

Sport climbing is a complex physical activity, involving strength, balance and dynamic coordination of movements of the lower and upper parts of the body.

The performance of a climber can improve with constant practice, but the precise execution of a sequence of climbing is a task that even a very expert alpinist can typically complete only after several cycles of trial and error, with macroscopic changes in terms of energy efficiency deriving from small posture variations, such as the inadequate positioning of one finger.

A clearer picture in the mechanics of climbing could be acquired by measuring the contact forces of the body of the climber against the wall.

So far, little has been done in this direction, mainly due to the high cost required by the ad hoc instrumentation of artificial walls.

Examples of hold devices are illustrated in the patent documents FR3017305A1, WO2017016246A1, US2010004098A1 and WO2012076825A1.

The document FR3017305A1 describes a hold device for climbing equipped with a load cell applied to the climbing wall, on the opposite side of the wall with respect to that on which the hold is applied.

In particular, the load cell of the hold device according to FR3017305A1 comprises a plurality of strain gages positioned on the fixing plate of the hold to the wall; with this configuration of the strain gages, the force applied on the hold is unloaded in part on the wall, and therefore a correct measurement - complete with deformation - cannot be obtained, according to which it would be possible to determine the components of force applied to the climbing hold; in particular, the deformation of the insert in the plane of the wall cannot be ascribed to the force applied to the hold along the three directions of space; moreover, the extent of the force is not independent of the point of application of the force on the hold itself; finally the use of a single strain gauge to measure a component of the force does not amplify the signal, nor allows a reduction of the components of signal noise, neither allows a resolution of the signal sufficient to measure small loads, such as, for example, the stress exerted by children.

More precisely, the hold device according to document FR3017305A1 has an arrangement of strain gauges in the radial and circumferential directions on the flange parallel to the plane of the climbing wall, subjected to bending in such a way as to deform itself in the same point under the effect of multiple strength components; consequently, the radial and circumferential bending deformation of a point of the flange, for a bending moment parallel to the plane of the flange, does not allow distinguishing the components of the forces applied to obtain the deformation.

Moreover, the hold device according to document FR3017305A1 has a number of strain gauges connected in a quarter bridge configuration: this arrangement does not allow nor to reduce the noise of the measurement neither to amplify the measurement itself. This solution, therefore, results incomplete in providing a clear picture in the mechanics of the user's climbing and, specifically, results unsuitable for providing a load resolution capable of allowing an accurate and appropriate processing also for the study of the movement in children.

The document WO2017016246A1 describes a climbing hold device containing a load cell of the conductive type, which is activated when the static electricity of the human body is detected.

In particular, the hold device according to the document WO2017016246A1, having a sheet of conductive material inserted inside the fastening insert of the hold to the wall, detects the presence of a human contact, thanks to the discharge of static current instantaneously produced by the part of the human body in contact with the hold itself; this information allows to monitor the time elapsing between a hold and another, and also to trace information relating to the path chosen.

However, the hold device according to the document WO2017016246A1, not being equipped for measuring nor force neither displacement or deformation, but being equipped only to detect a contact occurred between a conductor body and a climbing hold, does not allow measuring the strengths applied on the climbing hold and, therefore, to provide a clear picture of the climbing mechanics of the user.

The document US2010004098A1 describes a climbing hold device provided with lighting devices.

In particular, the hold device according to the document US2010004098A1 consists of a body, suitable to support hands and feet of the sportsman, made of transparent material and containing a light source therein.

However, the hold device according to the document US2010004098A1, being devoid of a load cell and a corresponding device for the force measurement, does not allow measuring the forces applied on the climbing hold and is, therefore, unsuitable to provide a clear picture of the climbing mechanics of the user.

The document WO2012076825A1 describes a climbing hold device provided with lighting devices to locate a path on an artificial wall for training.

In particular, document WO2012076825A1 illustrates a wall equipped with climbing holds that can be illuminated and identified uniquely that, via a remote control, allow generating a sequence of illuminated holds indicating the climber a predetermined path.

The device described in the document WO2012076825A1 is equipped for measuring nor force neither displacement or deformation, but is equipped only to distinguish the location of a specific climbing hold by selectively illuminating it, independently from the contact between the user and the hold; therefore, the climbing holds according to the document WO2012076825A1 do not allow measuring the forces exchanged between an athlete and a hold during the training (and, specifically, to measure the force applied on each hold) and, therefore, to provide a clear picture of the climbing mechanics of the user.

Examples of devices for hold devices are also illustrated in the following scientific literature:

- Fuss F. K„ Niegl G., "THE FUEEY INSTRUMENTED CLIMBING WALL: PERFORMANCE ANALYSIS, ROUTE GRADING AND VECTOR DIAGRAMS

- A PRELIMINARY STUDY" (2008), The Impact of Technology on Sport II, pp. 677-682, Taylor & Francis Group, London, UK

- Lechner, I. Filzwieser, M. Lieschnegg, P. Sammer, " A Climbing Hold With an Integrated Three Dimensional Force Measurement and Wireless Data Acquisition" INTERNATIONAL JOURNAL ON SMART SENSING AND INTELLIGENT SYSTEMS, VOL. 6, NO. 5, DECEMBER 2013

- Francesco Braghin, Federico Cheli, Stefano Maldifassi, Edoardo Sabbioni, and Marco Sbrosi, "An Experimental Study of Climbers Performances Based on Hand-Grip Force Measurement" R. Allemang et al. (a cura di), Topics in Modal Analysis II, Volume 6, Conference Proceedings of the Society for Experimental Mechanics Series 31, DOI 10.1007/978-l-4614-2419-2_52

Fuss F. K., Niegl G., "Instrumented climbing holds and performance analysis in sport climbing", DOI: 10.1002/ jst. 71

Fuss and Niegl made a wall with load cells capable of measuring six components of the load: three forces and three moments, obtaining a map of the applied forces; they used load cells that allowed obtaining a resolution of approximately 2 N, but this solution results expensive and difficult to implement outside a laboratory.

The solution by Lechner et al. is similar to that by Fuss and Niegl, and provides load cells capable to measure three force components; however, this solution has the further disadvantage of considerable dimensions of the load cell that, for safety reasons, must be protected with an appropriate guard and that can alter the characteristics of the climbing wall.

Braghin et al. made an experimental system with sensorized holds, each equipped with a single monoaxial load cell; the disadvantage of this solution is that it does not allow measuring the actual force applied on the hold itself. As discussed previously, the main limits and the disadvantages of climbing hold devices according to the prior art reside primarily in the impossibility of providing a clear picture of the climbing mechanics of the user to reconstruct spatially and temporally the detected force signals, of providing accurate and appropriate processing for any type of user; moreover, the sensorized climbing hold devices according to the prior art have high production costs.

Therefore, there is a perceived need for climbing hold devices that allow measuring precisely the forces applied by any user and to reconstruct spatially and temporally the measured forces.

More precisely, there is a perceived need for evaluating the user's performance for the purpose of sports training, rehabilitation or psychomotricity, both in real time and delayed time.

Furthermore, there is a perceived need for economy and containment of overall dimensions.

In summary, therefore, up to the present time, to the knowledge of the Applicant, there aren't any known technical solutions which allow overcoming the above underlined drawbacks.

Therefore, the Applicant, with the climbing hold device according to the present invention, intends to remedy this lack.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to overcome the drawbacks of the known art related to the definition of climbing mechanics.

It is the specific object of the present invention to provide a device for fastening climbing holds capable of acquiring, in space and time, the distribution of forces applied during the climbing activities for the purpose of sport, functional rehabilitation or psychomotricity.

Furthermore, it is an object of the present invention to provide a sensoried device for fastening climbing holds at a low cost and with minimum overall dimensions, both precise and accurate.

In summary, the present invention has the objectives of: acquiring the measurement of the forces applied to the hold for sport climbing in the space, and

- making available an economic equipment, that could be used in a field that typically requires limited investments.

These objectives are achieved with the device for fastening climbing holds according to the present invention which, thanks to a clearer understanding of the forces involved in the movement of climbing realized by means of a triaxial load cell, provides the basis for a scientifically rigorous interpretation of the complex mechanics of the body during the activity of sport climbing, necessary in a sport that so far is based solely on the subjective experience, and helps to improve the training and technique strategies, to reduce the possibility of injuries and to facilitate the approach of a broader audience to the climbing activities and to open air sports in general.

In particular, the device for fastening climbing holds according to the present invention is equipped with a triaxial load cell and a system for the acquisition and processing of force data both in real time and delayed time and, advantageously, allows measuring the contact forces between a climber and a climbing wall, data that can then be used to quantify the sports performances and provide guidelines and protocols for optimizing the training, for designing exercises of climbing for specific rehabilitation objectives and for improving the performance of a climber by means of a more aware analysis of the posture of his/her own body and movements.

Specifically, the above and other objects and advantages of the invention, as will appear from the following description, are achieved with a device for fastening holds as that according to claim 1.

Preferred embodiments and variants of the device for fastening climbing holds according to the present invention form the subject matter of the dependent claims.

It is understood that all the appended claims form an integral part of the present description, and that each of the technical characteristics claimed therein is possibly independent and can be used autonomously with respect to the other aspects of the invention.

It will be immediately apparent that countless modifications could be made to what described (for example related to shape, sizes, arrangements and parts with equivalent functionalities) without departing from the scope of protection of the invention as claimed in the appended claims.

Advantageously, the technical solution according to the present invention allows:

- the spatial and temporal reconstruction of the force signal thanks to the load cell being triaxal;

- the processing of information in real time or delayed time for the assessment of the user performances for the purpose of sports training, rehabilitation or psychomotricity;

- the study of the movements of any type of user, including children;

- the containment of overall dimensions; and

- the low production costs.

Further objects and advantages of the present invention will be more apparent from the detailed description that follows.

BRIEF DESCRIPTION OF FIGURES

The present invention will be described hereinafter by way of some preferred embodiments, provided by way of example and not of limitation, with reference to the accompanying drawings. These drawings illustrate different aspects and examples of the present invention and, where appropriate, similar structures, components, materials and/or elements in different figures are denoted by similar reference numerals.

FIG. 1 is a schematic representation of a non-sensorized climbing hold device according to the prior art, commercially available;

FIG. 2 is an exploded perspective view of the sensorized device for fastening holds for sport climbing according to the present invention;

FIG. 3 is an exploded perspective view of the metal insert and the bushing (which, together, constitute the triaxial load cell) of the sensorized fastening device according to the present invention;

FIG. 4 is a side view of the device of FIG. 2;

FIG. 5 is a perspective view of the device of FIG. 2; FIG. 6 shows the diagram of load distribution and internal action of the sensorized device for fastening holds for sport climbing according to the present invention - shown schematically - secured to a climbing wall and loaded transversely at its free end;

FIG. 7 shows the diagram of the connections of the strain gauges in the full bridge configurazion for the detection of a force component, Fx or Fy, in the plane of the climbing wall;

FIG. 8 shows the diagram of the distribution of the loads and the internal action of the sensorized device for fastening climbing holds according to the present invention - shown schematically - secured to a climbing wall and loaded axially at its free end; and

FIG. 9 shows the diagram of the connections of the strain gauges on the "Wheatstone Bridge" for the detection of a force component, Fz, perpendicular to the plane of the climbing wall.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications and alternative constructions, some preferred embodiments are shown in the drawings and will be described in detail hereinbelow.

It should be understood, however, that there is no intention to limit the invention to the specific embodiments illustrated, but, on the contrary, the invention is intended to cover all modifications, alternative constructions, and equivalents which fall within the scope of the invention as defined in the claims.

In the following description, therefore, the use of "for example", "etc.", "or", "either" indicates not exclusive alternatives without any limitation, unless otherwise indicated; the use of "also" means "including, but not limited to" unless otherwise indicated; the use of "includes/comprises" means "includes/comprises but not limited to" unless otherwise indicated.

The sensorized device for fastening climbing holds of the present invention is based on the innovative concept of incorporating a triaxial load cell in the fastening device of the hold. Actually, the inventors found that by suitably positioning the strain gauges on a metal insert and substituting this metal insert to the conventional screw that allows the application of the hold to the climbing wall, it is possible to acquire the force components strength exerted on the climbing hold along three directions, so as to allow the study, in space and time, of users' movements both in adults and children. An important characteristic of the sensorized device for fastening climbing holds of the present invention resides in the fact that, combined with an interface and a computer, it allows the processing of information in real time or in delyed time for the assessment of the user's performance for the purpose of sports training, rehabilitation or psychomotricity.

Referring to Figure 1, it can be observed that a traditional climbing hold 11 consists of a resin block having an appropriate shape 13, fastened to the artificial wall by means of screws 17, inserted in corresponding special compartments 15.

Referring to Figure 2, it can be observed that in the sensorized device for fastening climbing holds of the present invention, the screw that locks the climbing hold is not directly fastened to the wall, but in a metal insert joined to a bushing which, suitably sensorized, simultaneously act both as support and load cell.

To enable the sensorized device for fastening climbing holds of the present invention to fulfil both these functions, the Inventors have designed a suitable geometry of the metal insert, so that it acts as a strain gauge type load cell, and also as an adequate fastening system to the climbing wall, so as to allow loading the sensorized device properly so that it measures accurately the deformations and the forces applied on the hold.

A first aspect of the present invention, independent and that can be used autonomously with respect to other aspects of the invention, relates in particular to the preferred embodiment of the present invention illustrated in Figures 2, 4 and 5, a sensorized device for fastening climbing holds 10 including

- a plate 1;

a metal insert 2;

a disc 3 for fixing the sensorized device for fastening holds 10 to a climbing wall 6;

- a bushing 4;

a locking nut 5; and

- means (not shown) for anchoring said disc 3 to said climbing wall 6.

The sensorized device for fastening holds 10, as previously mentioned, in place of conventional fastening screw comprises a metal insert 2 and a bushing 4.

The metal insert 2 is provided with a first end 2a, arranged for connecting to plate 1 and to a climbing hold (not shown), and a second end 2b, threaded or otherwise arranged for connecting to disc 3.

Referring to Figure 3, and defined a cartesian reference system x, y, z for the device for fastening climbing holds 10, in which the x and y axes are contained in the plane formed by the climbing wall 6 and are mutually perpendicular, with x parallel to the ground on which the climbing wall (6) rests, and in which the z axis is perpendicular to the climbing wall 6 plane and parallel to the main axis of the device for hold device 10, it can be seen that the metal insert 2 in turn comprises

- two first pairs of strain gauges Al, A2 and A3, A4 positioned in a first plane zl parallel to the plane of the climbing wall 6, with the strain gauges arranged perpendicularly to said first plane zl and on diametrically opposite positions, in particular the pair Al, A2 is positioned in parallel to the direction of the x axis, and the pair A3, A4 positioned perpendicularly to the direction of the x axis and in parallel to the y axis;

- two second pairs of strain gauges Bl, B2 and B3, B4 positioned in a second plane z2 parallel to the plane of the climbing wall 6, spaced from the first plane zl and parallel thereto, with the strain gauges arranged perpendicularly to such second plane z2 and on diametrically opposite positions, in particular the pair Bl, B2 positioned in parallel to the direction of the x axis and the pair B3, B4 positioned perpendicularly to the direction of the x axis and in parallel to the y axis.

Always referring to Figure 3, it can be observed that the bushing 4 in turn comprises - two third pairs of strain gauges A5, A6 and B5, B6 positioned on a third plane z3 parallel to the plane of the climbing wall 6, spaced from the first plane zl and parallel thereto, and spaced from the second plane z2 and parallel thereto, with the strain gauges arranged perpendicularly to the such third plane z3 and on diametrically opposed positions, in particular each of the two third pairs A5, A6 and B5,B6 positioned in a plane perpendicular to the climbing wall 6, oriented with any angle around the z axis, but such that the planes of the two third pairs A5, A6 and B5, B6 are perpendicular to each other, more in particular the pair B5, B6 positioned in parallel to the direction of the x axis and the pair A5, A6 positioned perpendicularly to the direction of the x axis and in parallel to the y axis.

It should be underlined that the strain gauges can be replaced with equivalent detectors, for example with inductive elements; therefore, the term "strain gauge" in the present description means to include any deformation detector.

The metal insert 2 and the bushing 4 together constitute the triaxial load cell of the sensorized fastening device 10 according to the present invention.

As it can be noticed, in the preferred embodiment of the present invention, all the pairs of strain gauges have strain gauges arranged in parallel to the main axis of the sensorized device for fastening holds 10; however, it should be stressed that many other arrangements of the strain gauge are possible, for example even at 45 degrees with respect to one another, although arrangements different from that of the preferred embodiment may result less efficient.

The inventors have found the technical solution of the present invention that allows using the deformations of an interlocked beam, however measured, to determine the forces.

Preferably, the second plane z2 is spaced from the first plane zl by a distance ranging between 1 mm and 500 mm.

Preferably, the third plane z3 is spaced from the first plane zl by a distance ranging between 1 mm and 500 mm, and is spaced from the second first plane z2 by a distance ranging between 1 mm and 500 mm.

As said above and with reference to Figures 4 and 5, the plate 1 is secured to the first end of the metal insert 2; it ensures a large supporting surface of the climbing hold device 10.

As said above and with reference to Figures 4 and 5, the disc 3 is secured to the second threaded end of the metal insert 2; it serves for anchoring the sensorized device for fastening holds 10 to a wall 6 (visible in Figure 4), and precisely it is able to realize an interlocking constraint.

With reference to Figures 4 and 5, the locking nut 5 is screwed to the metal insert 2 and serves to secure the metal insert 2 to the disk 3.

The hold device 10 has dimensions compatible with the equipment for sport climbing; consequently, its component parts, in particular the metal insert 2 and the bushing 4, have adequate dimensions.

By way of example and not of limitation, the metal insert 2 of the sensorized device for fastening holds 10 has dimensions ranging between 1 mm and 300 mm, preferably dimensions ranging between 20 mm and 200.

By way of example and not of limitation, the bushing 4 of the sensorized device for fastening holds 10 has dimensions ranging between 1 mm and 70 mm, preferably dimensions ranging between 10 mm and 30 mm.

Preferably, the metal insert 2 of the hold device 10 is made of metal alloys or composite materials with high resistance, more preferably is made of steel, aluminum alloy, titanium alloys.

Preferably, the bushing 4 of the hold device 10 is made of a material with low elastic modulus, more preferably is made of a polymeric material or low resistance composite products.

Referring again to Figure 3, the best arrangement and the optimal number of strain gauges necessary to achieve the right compromise between a sufficiently precise signal and a low cost are shown.

Preferably, the strain gauges are located on a surface of the metal insert 2 and the bushing 4 so as to react to the minimum deformations of the metal insert 2 and the bushing 4 in any direction, generating the relevant electrical signal; however, strain gages can also be positioned on a different surface, for example on a surface coaxial to the metal insert 2.

The distance between the two first pairs Al, A2 and A3, A4 and the two second pairs Bl, B2 and B3, B4 of strain gauges must be the greatest possible to improve the quality of the electrical signal, compatibly with the mechanical strength of the metal insert 2; purely by way of example, but not by way of limitation, , the distance between the two first pairs Al, A2 and Bl, B2 and the two second pairs A3, A4 and B3, B4 of strain gauges ranges from 5 mm to 40 mm.

The "Wheatstone Bridge" connection of strain gauges belonging to the first two pairs Al, A2 and Bl, B2 and the two second pairs A3, A4 and B3, B4 provides the measurement of deformations of the metal insert 2 that, suitably processed, provides the value of the forces Fx and Fy.

More in particular, the strain gauges Al, A2 are connected in half bridge configuration and positioned on adjacent sides of a "Wheatstone Bridge", and the strain gages Bl, B2 are connected in half bridge configuration and positioned on the other two sides; together the two pairs constitute a full bridge configuration for the measurement of the force in the direction parallel to the direction defined by the intersection of the plane that contains the pairs Al, A2/B1, B2 and the climbing wall 6.

Similarly, the strain gages A3, A4 are connected in half bridge configuration and positioned on adjacent sides of a "Wheatstone Bridge" and the strain gages B3, B4 are connected in half bridge configuration and positioned on the other two sides; together the two pairs constitute a full bridge configuration for the measurement of the force in the direction perpendicular to the direction Al, A2/B1, B2.

This configuration, optimising the distance between the sections perpendicular to the axis of the metal insert 2 that contain the strain gages, allows disengaging the extent by the errors induced by the distance of the application point of forces, with respect to the plane of measurement.

The connection on opposite sides of a "Wheatstone Bridge" of the strain gauges belonging to two third pairs A5, A6 and B5, B6 provides the measurement of deformations of the bushing 4 which, suitably processed, provides the value of the force Fz.

More in particular, the pair of strain gauges A5, A6 is connected on opposite sides of a "Wheatstone Bridge" and provides the measurement of the force in the direction perpendicular to the plane of the wall 6; similarly, the pair of strain gauges B5, B6 is connected on opposite sides of a "Wheatstone Bridge" and provides a redundant measurement of the same component of force.

This configuration, doubling the signal relating to the axial deformation of the bushing 4, allows detecting even small values of deformation and, therefore, small values of force in a direction parallel to the z axis of the metal insert 2.

The device for fastening holds 10 according to the present invention allows to obtain a clearer picture in the mechanics of climbing thanks to the measurement of the contact forces of the climber's against the wall; specifically, a clearer understanding of the forces involved in the gesture of climbing is obtained as follows.

Generally, based on the cartesian reference system x, y, z defined for the device for fastening holds 10 - in which, ad already stated, x and y axes are contained in the plane formed by the climbing wall 6 and are mutually perpendicular, with x parallel to the ground on which the climbing wall 6 rests, and in which the z axis is perpendicular to the climbing wall 6 plane and parallel to the main axis of the device for hold device 10 - the hold device 10 detects deformation measures in the x, y and z directions, from which the force components Fx, Fy and Fz are obtained in the corresponding directions x, y and z.

As regards the measurement of a force component in the plane of the climbing wall 6, for instance Fx or Fy, such measurement is obtained from the measurement of the deformation of the metal insert 2 that, schematically, can be considered as an interlocked beam loaded at its free end, and thus subjected to bending by the applied load, for example, by grasping the climbing hold, for example by a climber hanging from the hold; Figure 6 shows the diagram of load distribution and internal actions of the sensorized device for fastening holds 10 for sport climbing according to the present invention - shown schematically as an interlocked beam - secured to a climbing wall

6.

To amplify the deformation signal and reduce the noise in the measurement due to random errors, deformations on diametrically opposite positions are detected that, during bending, will be one in traction and one in compression. By connecting the corresponding strain gages in a half-bridge configuration on a "Wheatstone Bridge", it is possible to determine the value of the force applied, for example, by grasping the climbing hold.

In order to disengage the measurement from the effect of the application point of the force, the measurement is acquired on two different sections, and precisely on the planes Z1 and Z2, which are connected in such a way as to constitute a full "Wheatstone Bridge", as explained below.

Always referring to Figure 6, an interlocked beam - which represents schematically the device according to the present invention - cantilever loaded in the direction perpendicular to the z axis, has a distribution of a bending moment Mf in correspondence with the plane positioned at a distance "a", measured from the interlocking along the z axis of the beam:

M_f(a) =— F(l - a)

In the case of a cylindrical section of the beam, having a diameter D, if the loads remain in the elastic field, the corresponding deformation e_z in the direction parallel to the z axis of the beam, at the generic coordinate "a" is:

-F(l - a) D

s_z(a) = +

EJ 2 where E is the elastic modulus of the material and J is the bending moment of inertia of the beam.

By connecting two strain gauges on a "Wheatstone Bridge" in a half-bridge configuration, and precisely Al, A2 in the x direction or A3, A4 in the y direction, positioned at the two ends of a diameter at the generic coordinate "a" which measure deformations having equal and opposite sign, a double value of deformation is detected and random errors result reduced, and precisely: -F(l - a) D

E_m (a) = ^£ _z(a) - [-E_z(a)] = 2s_z(a) = 2 - EJ 2

The value of the measured deformation being known, the value of the applied force can be traced back as follows:

s_m(a)EJ

F =

D(l - a)

If a second pair of strain gauges Bl, B2 for the x direction, or B3, B4 for the y direction, are positioned along the z axis of the beam at a distance L from the previous one, the measurement of deformation that is obtained is:

Referring to Figure 7 it can be observed that, by connecting the two half-bridges Al,

A2 and Bl, B2 for the x direction, or A3, A4 and B3, B4 for the y direction, in such a way that they form a full bridge, the following measurement is obtained:

From this deformation measurement, it is possible to trace back the extent of the applied force, except the sign:

With the first strain gauge bridge Al, A2 and Bl, B2 arranged in the horizontal plane perpendicular to the climbing wall 6, that contains the x direction and the axis of the beam, the measurement of Fx is obtained.

With the second strain gauge bridge A3, A4 and B3, B4 disposed in a vertical plane perpendicular to the climbing wall 6, that contains the y direction and the axis of the beam, the measurement of Fy is obtained.

With reference to Figures 8 and 9, as regards the extent of the force in the z direction parallel to the axis of the device Fz, a pair of strain gauges, and precisely a5, A6 and B5, B6, is mounted on opposite sides of an additional "Wheatstone Bridge", on an element coaxial to the axis z of the beam and integral with the beam itself at a generic distance "b" from the origin of the reference system.

The strain gages A5, A6 and B5, B6 thus arranged are able to detect only the axial component of the deformation, while the bending one will be self-deleted because of opposite sign.

The hold device 10 further comprises an interface 12, positioned downstream the metal insert 2, and also a computer 14 of the forces Fx, Fy and Fz, positioned downstream the interface 12.

During the operation, i.e. during the climbing by the climber, the strain gauges communicate the detected deformation data, which are suitably conditioned and sampled at a frequency selectable between about 1 Hz and 100 Hz, via such interface 12 to a unit for the data collection and analysis 14.

The data transmission takes place via a wireless or wired interface, for example via a CAN (Controller Area Network) bus with a standard protocol.

The data is collected from a remote unit equipped with a processor and a memory sufficient for storing and processing the data received in a time interval depending on the required analysis; the remote unit is able to reconstruct the force signal from each cell in time and space, and to communicate this data through an additional wired interface, for example with Transmission Control Protocol (TCP) or User Datagram Protocol (UDP), to an application installed on a device (for example a phone, a PDA or a computer) available to the user, who can then easily use such high resolution information for the purposes indicated, in real time or in delayed time.

The effectiveness of the technical solution according to the present invention are hereinafter demonstrated by the following experimental analysis, which is meant as illustrative, but not limitative of the present invention.

The FEM ("Finite Element Method", finite elements method) analysis was performed on various geometries of the metal insert 2 instrumented for the structural check and the optimization of performance, in particular maximization of the deformations along with structural resistance and safety.

The best arrangement and the best number of strain gauge cells necessary to achieve the right compromise between a sufficiently precise signal and a low cost have been determined.

The hold device equipped with the triaxial load cell was fitted with a data acquisition system (DAQ, "Data AcQuisition") consisting of a signal amplifier, an analog-to-digital converter, a microcontroller and a communication module on CAN ("Controller Area Network") bus, designed so as to have adequate characteristics (bandwidth = 100 Hz, resolution = 1 N, range = + 5 kN) and low cost.

As regards the experimental validation of the device 10 according to the present invention, a series of tests was performed to check repeatability, linearity, sensitivity, resolution, and stability of the device itself.

The device was mounted with the axis perpendicular to the plane of a plate, which in turn was mounted vertically on a workbench with guides by means of a system of clamps.

The plane, containing the strain gages Al, A2 and Bl, B2, with which the measurement was carried out, and containing the axis of the device, was oriented so as to be initially vertical.

Test loads were applied to the cantilever end, i.e to the free end of the device, by means of a weight holder plate.

5 weights of 50 N each were applied in succession, so as to increase linearly the load and check the linearity of the detection.

Measurements were taken also during the unloading phase, to examine the possible elastic hysteresis.

The measurements were repeated three times to check the repeatability.

The tests were carried out in four different configurations:

- Test 1: the plane containing the strain gages Al, A2 and Bl, B2 was arranged vertically and in parallel to the direction of the load;

- Test 2: the plane containing the strain gages Al, A2 and Bl, B2 was rotated by 45° about the z axis;

- Test 3: the plane containing the strain gages Al, A2 and Bl, B2 was arranged horizontally, perpendicularly to the direction of the load; and

- Test 4: the plane containing the strain gages Al, A2 and Bl, B2 was arranged again vertically and in parallel to the direction of the load, to check again the repeatability.

By way of example and not limitation, the average results of the tests relating to the above tests are reported below:

Test 1 _ Test 2 _

Measured deformation Applied force Measured

Applied force [N]

_ [pm/m] _ [N] deformation [pm/m 0 0 0 0

49.0 65.9 49.0 47.3

98.1 131.5 98.1 94.4

147.1 197.5 147.15 141.8

196.2 263.0 196.2 189.5

245.2 328.8 245.2 237.5

Test 3 _ Test 4 _

Measured deformation Applied force Measured

Applied force [N]

[pm/m] [N] deformation [pm/m

49.0 3.8 49.0 66.1

98.1 6.1 98.1 130.1

147.1 9.9 147.15 195.8

196.2 10.7 196.2 264.3

245.2 13.2 245.2 329.0

Another series of tests was carried out to verify the operation of the bushing.

In particular, the device was mounted on the same workbench of the previous tests and with the z axis vertical and perpendicular to the ground on which the climbing wall 6 rests; the test loads were applied to the cantilever end, i.e to the free end of the device by means of a weight holder plate.

The measurements were repeated three times to check the repeatability.

The average results are reported below: Applied force [N] Measured deformation [pm/m]

0 0

49 170.9

98.1 341.4

147.1 511.9

196.2 659.0

245.2 813.4

294.3 934.4

The experimental tests have demonstrated that the response of the device according to the present invention is positive in terms of linearity and independence from the application point of the force, thereby achieving the proposed objects.

A hold for sport climbing constitutes a further independent aspect and can be used autonomously with respect to the other aspects of the invention, comprising

a shape of the known type used for sport climbing and similar activities (not shown); and

a fastening sensorized device for holds 10, as previously described in detail, for fastening the shape to a climbing wall 6.

As it can be deduced from the foregoing, the innovative technical solution described here has the following advantageous features:

spatial and temporal reconstruction of the force signal thanks to the sensor being triaxal;

- processing of information in real time or delayed time for the evaluation of the user's performances for the purpose of sports training, rehabilitation or psychomotricity;

study of the movements of any type of user, including children;

- containment of overall dimensions; and

- low production costs.

From the description above it is therefore apparent how the sensorized device for fastening climbing holds for sport climbing according to the present invention allows achieving the intended objects. Therefore, it is apparent to a person skilled in the art that it is possible to make modifications and further variants to the solution described with reference to the accompanying figures, without departing from the teaching of the present invention and from the scope of protection, as defined by the appended claims.

Claims

1. A fastening sensorized device for holds (10) for sport climbing comprising

- a plate (1);

- a metal insert (2);

a disc (3) for fixing the fastening sensorized device for holds (10) to a climbing wall (6);

- a bushing (4);

- a locking nut (5); and

- means (7) for anchoring said disc (3) to said climbing wall (6),

characterized in that said metal insert (2) comprises in turn

- two first pairs of strain gauges (Al, A2 and A3, A4) positioned in a first plane (zl) parallel to the plane of the climbing wall (6), with said strain gauges arranged perpendicularly to said first plane (zl) and on diametrically opposite positions, in particular the pair (Al, A2) positioned in parallel to the direction of the x axis and the pair (A3, A4) positioned perpendicularly to the direction of the x axis and in parallel to the y axis;

- two second pairs of strain gauges (Bl, B2 and B3, B4) positioned in a second plane (z2) parallel to the plane of the climbing wall (6), spaced from the first plane (zl) and parallel thereto, with said strain gauges arranged perpendicularly to said second plane (z2) and on diametrically opposite positions, in particular the pair (Bl, B2) positioned in parallel to the direction of the x axis and the pair (B3, B4) positioned perpendicularly to the direction of the x axis and in parallel to the y axis, and characterized in that said bushing (4) comprises in turn

- two third pairs of strain gauges (A5, A6 and B5, B6) positioned on a third plane (z3) parallel to the plane of the climbing wall (6), spaced from said first plane (zl) and parallel thereto and spaced from said second plane (z2) and parallel thereto, with said strain gauges arranged perpendicularly to said third plane (z3) and on diametrically opposed positions, in particular each of said two third pairs (A5, A6 and B5, B6) positioned in a plane perpendicular to the climbing wall (6), oriented with any angle around the z axis but such that the planes of said two third pairs (A5, A6 and B5, B6) are perpendicular to each other, wherein said two first (Al, A2 and A3, A4), two second (Bl, B2 and B3, B4) and two thirds (A5, A6 and B5, B6) pair of strain gauges, connected to each other, detect the forces (Fx; Fy; Fz) applied by a user (U) in the directions (x; y; z) of a Cartesian reference system (x, y, z) defined for said fastening device for holds (10), in which the x and y axes are contained in the plane formed by said climbing wall (6), with x perpendicular to said climbing wall (6), and in which the z axis is parallel to the main axis of said fastening device for holds (10), said metal insert (2) and said bushing (4), taken together, thus acting as a triaxial force sensor for said fastening device for holds (10).

2. A fastening sensorized device for holds (10) according to claim 1, wherein all said pairs of strain gauges have said strain gauges arranged in parallel to the main axis of said fastening sensorized device for holds (10).

3. A fastening sensorized device for holds (10) according to claim 1 or 2, wherein said strain gauges are positioned on a surface of said metal insert (2) and of said bushing (4) or on a surface coaxial to said metal insert (2).

4. A fastening sensorized device for holds (10) according to any of the preceding claims, further comprising an interface (12) located downstream said fastening sensorized device for holds (10).

5. A fastening sensorized device for holds (10) according to claim 4, further comprising a computer (14) of said forces (Fx; Fy; Fz) located downstream said interface (12).

6. A fastening sensorized device for holds (10) according to claim 5, wherein said computer (14) provides a real-time output.

7. A fastening sensorized device for holding (10) according to claim 5, wherein said computer (14) provides an output delayed over time.

8. A fastening sensorized device for holds (10) according to any of the preceding claims, wherein said metal insert (2) is made of metal alloys or of high strength composites, preferably is made of steel, aluminum alloy, titanium alloys.

9. A fastening sensorized device for holds (10) according to any of the preceding claims, wherein said bushing (4) is made of a material having a low elastic modulus, preferably is made of polymer material or of low strength composites.

10. A hold for sport climbing comprising

- a shape; and

- a fastening sensorized device for holds (10) according to any of the preceding claims for fastening said shape to a climbing wall (6).