WO2016020876A1

WO2016020876A1 - Fastening device for filiform materials and similar products

Info

Publication number: WO2016020876A1
Application number: PCT/IB2015/055977
Authority: WO
Inventors: Dante Bruno Priuli
Original assignee: Schnell S.P.A.
Priority date: 2014-08-08
Filing date: 2015-08-06
Publication date: 2016-02-11

Abstract

The fastening device for filiform materials and the like comprises a tightening member (2) predisposed to perform the tightening of at least one portion of wire prearranged at a fastening zone, and to perform the fastening of the tightened wire by twisting about a same fastening axis (A).

Description

FASTENING DEVICE FOR FILIFORM MATERIALS AND SIMILAR PRODUCTS

Technical Field

The present invention concerns a fastening device for filiform materials and similar products.

Background Art

It has been known that equipments for fastening filiform metal materials and the like are used, for example to manufacture cages or metal reinforcement nets for reinforced concrete, or protection nets, enclosures predisposed for use in different technical fields. The equipments of the most widespread use are of the manual type, for example of the pliers type. In substance, the operator prepares a piece of metal wire around the area whereby it is necessary to carry out the fastening, leaving respective ends protruding from one side. The pliers member tightens the ends and then twists them about themselves by means of the rotation imparted by the operator.

In certain other known equipments, the rotation can be semi-automatic, by the use of a worm screw operated by the operator and drawn back in position by elastic means.

Obviously, such manual equipments involve relatively long time for carrying out the fastening, as well as high costs for the considerable employ of labour.

In addition, it should be considered that the accuracy of the manually performed fastening significantly depends on manual skills and expertise of the operator, not however ensuring the repeatability of the results.

Patent DT 2458133 discloses a fastening device for fastening metal wires comprising a casing within which the tip of a spindle is axially slidable and rotatable. The casing also comprises an opening for the insertion of portions of wire to fasten, predisposed to be engaged by the rotating tip, to tighten the same portions and carry out the fastening.

Patent GB 2329140 discloses a fastening device comprising a gripping portion for at least one tract of wire to fasten, and control means to operate the handling of the gripping portion and to perform the twisting of the gripped tract of wire about a further portion of wire.

Automatic devices have been recently proposed for fastening wires or similar products, which, however, are necessarily associated with dedicated and complex power equipments, not always available on site.

The fastening solutions of known type, therefore, do not meet the needs of the specific field, in particular as regards the repeatability, precision and effectiveness of the results, the cost and flexibility of use.

Disclosure [1 1 ] The task of the present invention is to solve the aforementioned problems, devising a fastening device for filiform materials and similar products which allows to carry out the fastening of metal wires in an effective, precise and repeatable way.

[12] Within such task, it is a further scope of the present invention to provide a fastening device for metal wires and similar products of simple constructive and functional conception, provided with safe and reliable use, as well as relatively economic cost.

[13] A further scope of the present invention is to provide a fastening device for metal wires of flexible use, in particular easy to fit to materials of different transversal cross-section.

[14] The cited scopes are attained, according to the present invention, by the fastening device for metal wires according to claim 1 .

[15] The fastening device for metal wires and similar products, according to the invention, comprises a tightening member provided with a tightening operative portion, predisposed to carry out the tightening of at least one portion of filiform material wound at a fastening zone, and to perform the fastening of the same portion of tightened filiform material by twisting respective branches of the above mentioned tightened portion about a fastening axis, performing the rotation of the above mentioned tightening member about a longitudinal axis, which results to be a fastening axis for the so performed fastening.

[16] The cited fastening zone comprises at least one element to be fastened. For example, the fastening zone is represented by the overlapping of a first and a second element to be fastened, such as preferably a first metal rod and a second metal rod overlapped in crossed way.

[17] The device comprises as well a casing bearing the tightening member along the above mentioned longitudinal axis. In particular, the aforesaid casing is preferably of containment, at least partial, of the tightening member.

[18] The casing has an inlet portion, for covering the tightening member.

[19] According to the invention, the inlet portion comprises an opening arranged about the same longitudinal axis, predisposed to allow the insertion of the portion of filiform material to be tightened, and an activation assembly sliding along the same longitudinal axis with respect to the casing to apply a tightening activation force. In this way, the operative portion of the tightening member is operated, in particular handled, from an inactive configuration to a tightening operative configuration.

[20] In particular, when the operative portion of the tightening member is in the above mentioned operative configuration, it tightens the portion of filiform material inserted in the above mentioned opening, at the longitudinal axis of the fastening device, so as to carry out a tensioned, regular and perfectly repeatable fastening.

[21 ] It is important to underline that the operative portion of the tightening member, predisposed to tighten the filiform material, is substantially fixed in axial direction inside the above mentioned casing, at least when it is held in the tightening operative configuration.

According to an aspect of the invention, the above mentioned operative portion of the tightening member, in the inactive opening configuration, encloses the above mentioned opening. Therefore, the branches of the portion of filiform material to be tightened are efficiently inserted inside the same opening, independently from the respective orientation. In practice, the operative portion of the tightening member, thanks to such circumstance, is able to receive the branches of the portion of filiform material to be tightened, which can have whatever orientation, making unnecessary any previous orientating operation of the same branches to be tightened, with respect to the tightening member or vice versa.

The opening borne by the cited inlet portion has a shape predisposed to guide the portion of filiform material to be tightened towards the longitudinal axis of the device, to allow the tightening at the same axis.

According to an advantageous aspect of the invention, the opening of the cited inlet portion has a flaring shape, converging towards the inside of the casing of the fastening device, so as to ensure the insertion of the portion of the wire to be tightened and their guiding towards the longitudinal axis of the device, with any starting orientation.

The activation assembly comprises as well a connection member for the connection with actuation means, which allows to drive the rotation of the tightening member about the above mentioned longitudinal axis, to perform the fastening of the tightened portion of filiform material.

The cited connection member is preferably out of the containment casing, for an easy connection with the actuation means.

According to a prerogative of the invention, the connection member allows the removable connection with the fastening device with a portable tool, for example of known type, to operate the rotation of the fastening member.

The above mentioned portable tool can indifferently be of electric, hydraulic, pneumatic, manual type or other type.

The containment casing for the tightening member preferably acts as a protection for the tightening member, making the operation and the functioning of the same member thoroughly safe for the operator, who, in this way, does not risk to touch any moving members causing dangerous situations.

According to a particular aspect of the invention, when the operative portion of the tightening member is in the operative tightening configuration, it lays in a condition of stable balance. Therefore, upon reaching such configuration, the tightening member automatically remains in such configuration, also after removing the above mentioned activation force, which serves to bring the operative portion from the inactive configuration to the operative configuration.

According to an advantageous aspect of the invention, the above mentioned inlet portion has an abutment rim, predisposed to act as support or abutment for the fastening zone, to exert the activation force which causes the tightening of the portion of filiform material, through the above mentioned activation assembly.

This circumstance, concerning the abutment of the abutment portion against the fastening zone, represented by at least one element to be fastened, usually a joint constituted by a first metal bar and by a second metal bar, is very important. As a matter of fact, such abutment, produced by the contact between the inlet portion against the fastening zone, combined with the fact that the operative portion of the tightening member performs the tightening of the filiform material at a fixed position along the longitudinal axis of the fastening device, allows to carry out a tensioned, repeatable and regular fastening.

More precisely, a prerogative of the invention is that the above mentioned operative portion of the tightening member tightens the portion of filiform material along the cited longitudinal axis and at a distance substantially fixed from the abutment portion, the same abutment portion being placed against the fastening zone, that is against the at least one element to be fastened, to carry out the fastening. Therefore, in such working condition the portion of filiform material tightened by the operative tightening portion is at the cited substantially fixed distance from the at least one element to be fastened.

Moreover, such substantially fixed distance is held until the complete achievement of the fastening, that is both during the tightening step and during the rotation step about the above mentioned longitudinal axis, thus obtaining a fastening wound in tensioned manner about the fastening zone and twisted in regular manner along the longitudinal fastening axis.

The cited inlet portion is arranged as a cover for the above mentioned operative portion both in the inactive configuration, in order to let the cited opening free for the insertion of the portion of filiform material to be tightened, and in the operative tightening configuration, at which the cited operative portion axially tightens the portion of filiform material and is arranged at a substantially fixed distance with respect to the abutment portion placed against the fastening zone, to carry out a fastening wound in tensioned manner about the fastening zone and twisted in regular manner along the longitudinal fastening axis.

Preferably, the above mentioned activation force is by push.

Likewise, according to the invention, it is possible to provide that the above mentioned activation is by traction, exerted through the command unit, instead of by push. In this case, the abutment rim against the fastening zone can, for example, be hook-shaped. Such rim can have a flat abutment or support surface or, as an alternative, an irregular abutment surface, predisposed to act as receiving seat for at least one element which represents the fastening zone. In this case, the one of irregular surface, the above mentioned rim, for example, can comprise one or more depressions, which usefully prevent the casing to from being drawn during the above mentioned rotation motion.

It is important to underline that, according to the invention, the distance between the cited fastening zone and the operative portion of the tightening member of the filiform material, which itself is substantially fixed in axial direction inside the above mentioned casing in the tightening operative configuration, is substantially constant in use, as long as the fastening zone is in abutment against the rim of the cited inlet zone.

As a matter of fact, it is important to underline that, when the portion of filiform material is tightened by the operative portion of the tightening member and operated in rotation about the fastening axis, the filiform material, further to the twisting produced by rotation, takes a progressively shortened configuration. The material is finally subjected to traction, when the above mentioned shortened configuration of the fastening being created is shorter than the substantially constant distance between the abutment rim of the inlet portion and the operative tightening portion.

In practice, in case there are at least two elements to be fastened, such traction firstly performs the approaching of the elements to be fastened until the minimum possible distance, then causes a corresponding progressive tensioning of the twisted filiform material.

Therefore, it is possible to say, that at the end of the fastening step, the fastened elements, in case being at least two, result to be joined in safe way as well as pre- tensioned by the same fastening.

The fastening per se, due to such traction, shapes regular helixes extended about a perfectly rectilinear axis coinciding with the fastening axis.

According to the invention, the fastening device can be connected with a screw tool of known type, able to exert high torques to create fastenings tightened in safe way.

The drill or screw gun usually comprises a torque limiter which, upon reaching the set value, causes twisting vibrations and, moreover, generates, during rotation of the mandrel, a percussion or hammering. These functions have advantageous effects on the manufactured fastening, as they contribute to better tighten and tension the fastening, increasing the accuracy of the result.

Therefore, according to the invention, it is possible to obtain a safe, pre-tensioned fastening in an easy way through the removable connection of a portable tool which is as well of economic purchase and reduced energy consumption. According to the invention, it is possible to intercept a wire simply wound or more wires with the same tightening member, so as to carry out a correspondently simple fastening, double, or with more wires of any type. In each case the fastening can result pre- tensioned, as previously described.

According to an advantageous aspect of the invention, the tightening member is connected with the above mentioned activation assembly through an articulation leverage to transmit and preferably increase the activation force, preferably a push one, which is then exerted by the tightening member on the filiform material.

The above mentioned leverage can have articulation pivots spaced from the longitudinal axis, to minimize the transversal space required by the same fastening device.

According to a very advantageous aspect of the invention, the above mentioned tightening member shapes pliers or a pincer, comprising respective tightening jaws hinged at a transversal pin.

The transversal pin is preferably fixed in direction axial with respect to the containment casing, so as to keep constant the distance between the fastening zone, placed in abutment against the rim of the inlet portion, and the tightening operative portion.

According to an advantageous aspect of the invention, such transversal pin can be split in a couple of transversal pins, spaced from the above mentioned longitudinal axis, so as to free an axial channel, useful for the insertion of the portion of filiform material to fasten. According to a further aspect of the invention, the tightening member of the fastening device is made up of a couple of elements having the shape of blades, sliding alternatively between an inactive configuration, with reciprocally spaced blades, and an operative position, converging at the opening of the above mentioned inlet portion. Preferably, the above mentioned blades slide at suitable guides obtained inside the containment casing, upon operation of the above mentioned activation member.

According to a particular aspect of the invention, the pliers, blades or other tightening member, shapes tightening portions having sharp edges, intended to intercept the filiform material, performing the tightening and preventing the axial sliding. Such feature allows and fosters the tensioning of the fastening. In substance, the above mentioned tightening portions are predisposed to tighten the filiform material at a respective sharp edge instead of a substantially flat surface, preventing the axial sliding thereof.

Moreover the sharp shape of the edges of the tightening portions, being jaws or blades, allows as well the cutting of the filiform material, at the end of the fastening.

Therefore, the so produced fastening, preferably has a net end cut, free of not twisted or fastened end tracts. According to an advantageous aspect of the invention, the ends of the tightening portions, for example being jaws, are interchangeable, to ensure the prompt replacement in case of wear and tear.

It is important to underline that according to the invention the fastening device can comprise technically equivalent tightening means, which use different means, such as for example, endless screw means, preferably with pre-load action, fluid dynamic, magnetic or further equivalent means.

The invention concerns as well a method for carrying out the fastening and the fastening itself.

In particular, the fastening according to the invention, carried out by prearranging at least one filiform material about a fastening zone comprising at least one element to fasten, comprises a portion wound about the above mentioned fastening zone and a twisted portion of respective branches of the same fastening about a longitudinal fastening axis. A feature of the fastening according to the invention is that the above mentioned wound portion is tensioned about the fastening zone, so as to be adherent and tangent to the profile of the fastening zone, and in that the twisted portion is tensioned and arranged along the longitudinal fastening axis, with a regular twisting pitch.

A feature of the invention is represented by the fact that the fastening is made through filiform material having a diameter comprised between 0,8 mm and 4 mm.

A feature of the same fastening is as well that it can fasten in tensioned manner a first element or rod having a diameter up to 20 mm with a second element or rod having a diameter up to 60 mm.

Therefore, the fastening can be advantageously used to fasten very heavy elements or reinforcements, which could not hold up with thinner filiform material, or in the absence of the aforementioned tensioning. In particular, structures effectively fastened may weigh substantially up to 6 tons.

According to a particular aspect of the invention, the fastening can have a cut free end, at the same twisted portion.

In particular, such cut can be performed through the same tightening member of the fastening device, suitably adjusting the torque exerted further to the rotation of the same member about the above mentioned longitudinal axis. After having twisted the branches of the filiform material, in case the torque is high enough, the rotation causes in fact a progressive notch at the tightened portion of filiform material, which weakens the respective portion, until the cutting thereof.

Description of Drawings Details of the invention shall be more apparent from the detailed description of a preferred embodiment of the fastening device for metal wires and similar products according to the invention, illustrated for indicative purposes in the attached drawings, wherein:

figures 1 and 2 respectively show a perspective view, from different opposite corners, of the fastening device according to the invention, with the casing being in cross-section according to a medial axial plane;

figures 3 and 4 respectively show a perspective view, from opposite corners, of the same device, rotated according to the longitudinal axis by 90° with respect to the figures 1 and 2, with the casing being in cross-section according to a median axial plane turned by 90°; figures 5 and 6 show an axial cross-section view of the fastening device according to the invention, respectively in an inactive configuration and in an operative configuration;

figure 7 shows a cross-section view of the fastening device, in the above mentioned operative configuration, according to an axial plane orthogonal to the plane of the cross- sections shown in figures 5 and 6;

figure 8 shapes a plant view of the same fastening device;

figures 9 and 10 show an axial cross-section view of the fastening device in a second embodiment of the invention, respectively in the above mentioned inactive and operative configuration;

figure 1 1 shows a cross-section view of the fastening device shown in figures 9 and 10, according to a plane orthogonal to the plane of the cross-sections shown in the above mentioned figures;

figures 12 and 13 show a plant view of a detail of the fastening device shown in figures 9 and 10, respectively deprived of a casing portion and provided with the same;

figures 14 and 15 show an axial cross-section view of the fastening device in a third embodiment of the invention, respectively in the above mentioned inactive and operative configuration;

figure 16 shows an axial cross-section vies according to an axial plane rotated by 90° with respect to the cross-sections shown in figures 14 and 15;

figures 17 and 18 show a plant view of the device shown in figures 14 to 16, respectively with and without a part of the containment casing;

figures 19 and 20 show a perspective view of the device according to a fourth embodiment with the protection casing in cross-section according to an axial plane, respectively according to opposite corners;

figure 21 shows a perspective cross-section view according to the same axial plane of the device shown in figures 19 and 20; figures 22 and 23 show a cross-section view of the device in a fifth embodiment, according to an axial plane, respectively in the above mentioned inactive and operative configuration;

figure 24 shows a cross-section view of the device shown in figures 22 and 23, according to an axial plane rotated by 90°;

figures 25 and 26 show a plant view of the same device, respectively with and without a part of the covering casing;

figure 27 shows a cross-section view of the device shown in figures 22 and 23, complementary to the cross-section shown in figure 24;

figures 28 to 30 respectively show an axial cross-section view of the fastening device according to a sixth embodiment in a inactive and operative condition, and a plant view of a cross-section according to a plane orthogonal to the axis of the same device, having trace XXX-XXX indicated in figure 28;

figures 31 and 32 show a schematic view in axial section of a seventh embodiment, in inactive and operative configuration respectively;

figures 33 and 34 show a schematic view in axial cross-section of an eighth embodiment, in inactive and operative configuration respectively;

figures 35A and 35B show respective views in cross-section of a fastening according to the invention, in subsequent steps;

figures 36 and 37, finally, respectively show a front cross-section view of a fastening according to the invention and of a traditional fastening.

Best Mode

With particular reference to such figures, the fastening device for filiform materials and similar products, has been indicated for more clarity in its entirety with 1 . The above mentioned filiform materials can be predisposed, for example, in single crops, of a determined length and possibly also preformed, to be wound in any way and tightened about a fastening zone represented by at least one element to fasten.

The fastening device 1 according to the invention is predisposed to carry out any type pf fastening, for example, simple, double, crossed, in any case by twisting the filiform material about a same fastening axis.

For example, the fastening zone can comprise the overlapping zone of a first element of elongated shape, preferably rigid, with a second element of elongated shape, preferably rigid as well. The fastening device 1 is therefore predisposed to carry out the union through fastening of the first element and of the second element at the overlapping zone. The filiform material, which can be covered with suitable material or not covered, is therefore preferably predisposed in preformed crops having U-shape, so as to wind the elements to join and adress to the fastening device a couple of substantially parallel ends to be twisted.

The cited first and second element, to join by fastening, can for example comprise longitudinal metal elements to fasten at junctions or overlapping, or longitudinal and transversal metallic elements to fasten at intersections respectively, intended to manufacture metal cages or metal nets for the reinforcement of building structures, for enclosures or other purposes. For example, the elements to join can comprise a longitudinal element, such as a reinforcement bar and a transversal element such as a reinforcement stirrup, to manufacture reinforced concrete building structures.

However, the fastening device, can be used also in a different way, for fastening a single element at a fastening zone through a filiform material, for example a metal wire o similar product, which is already predisposed or can be wound, preferably having U-shape.

In each case, more precisely, for "fastening" is meant the helical twisting along a fastening axis A, of the filiform material, for example of the cited wire ends, one about the other, until tightening, according to the use requirements, the involved fastening zoneof the elements to join.

Therefore, the fastening device 1 comprises a tightening member 2 for a portion of the filiform material or fastening wire, an activation assembly 3 of the tightening which can be operated by the tightening member 2, a protection casing 4 containing the tightening member 2 and the activation assembly 3.

Preferably, the fastening portion of the filiform material is represented by ends of a crop of filiform material or wire.

As an alternative, such portion could be provided by a median portion, for example central, of a crop of filiform material, in which the respective ends are reciprocally hooked or united about the fastening zone.

In particular, the casing 4, preferably of cylindrical tubular shape, has at one end an inlet portion 5 for the insertion of the fastening portion of filiform material. In practice, the inlet portion 5 shapes an opening 6, preferably having flaring or funnel shape, converging towards the inside of the casing 4, to ease the insertion of the above mentioned portion of filiform material to twist. The opening 6 is delimited, out of the casing 4, by an abutment rim 7, preferably annular, predisposed to act as abutment or stop.

The annular rim 7 preferably shapes a flat surface orthogonal to the longitudinal axis A of the same casing 4, coinciding with the cited fastening axis A. Alternatively, the rim 7 can have an irregular surface, given that it is suitable for abutting the fastening zone.

The tightening member 2 is contained inside the casing 4, with the corresponding operative portion, for the tightening of the inserted wire, turned towards the above mentioned opening 6. More precisely, the tightening member 2 is preferably a pliers or pincer member.

[81 ] The operative portion of the pliers member is represented by a first jaw 21 and by a second jaw 22, pivoted at a pin 23 transversal to the axis A, substantially fixed in axial direction.

[82] The first jaw 21 and the second jaw 22 are carried at the ends of a respective first arm 24 and of a respective second arm 25 of the tightening member 2, to transmit the required tightening force to the above mentioned operative portion, upon command of the activation assembly 3, as it is better described in the following.

[83] Therefore, the first jaw 21 and the second jaw 22 of the tightening member 2 are mobile, upon command of the activation assembly 3, between an inactive opening configuration, to intercept a portion of filiform material to fasten, and an operative tightening configuration, at which the first jaw 21 and the second jaw 22 tighten between them the above mentioned intercepted portion of filiform material with a force proportional to the activation force applied through the first arm 24 and the second arm 25.

[84] Preferably, the first jaw 21 and the second jaw 22 address to the portion of filiform material to be tightened a minimal surface.

[85] Such circumstance, of minimal contact surface, is obtained for example through a sharp edge configuration of the tightening ends of the above mentioned jaws 21 , 22. Such sharp edge configuration is useful to concentrate the tightening action on a corresponding minimal surface of the tightened portion of filiform material.

[86] Moreover, the sharp edge shape, besides efficiently tightening the filiform material, also prevents its sliding. Such feature allows and enhances the tensioning of the fastening, locking the tightened filiform material at a substantially fixed distance from the fastening zone. In substance, the above mentioned tightening portions are predisposed to tighten the filiform material at a respective sharp edge instead of a substantially flat surface, preventing its axial sliding during the twisting about the fastening axis, thus imparting a straight and rectilinear shape, with regular twisting pitch, to the twisted portion C (see figure 36).

[87] Moreover, the sharp edge shape of the tightening portions allows as well the cut of filiform material, at the end of the fastening step, at the tightened portion and so of the end of the twisted portion C, imparting an optimal finishing to the fastening. Such cut imparts a higher safety for the operator which is charged with the handling of the fastened structure, reducing the extension of the end portion G protruding from the twisted portion C, to a minimum.

[88] The tightening action to be exerted on the arms 24, 25 results reduced, due to the particular conformation, at equal required tightening. In is to observe that both in the inactive and in the operative configuration, the first jaw 21 and the second jaw 22 are axially backed, that is protected, from the inlet portion 5 inside the casing 4 of the fastening device 1 beyond the annular rim 7.

Preferably, the end portion of the first jaw 21 and of the second jaw 22 are arranged at a height below the opening 6, accessible, through the same opening 6, for the portion of filiform material to fasten and, at the same time, being safe for the operator.

The activation assembly 3 is made, for example, of a command member 40, intended to apply an activation force to the tightening member 2, corresponding to the force required for the tightening of the filiform material.

The required activation force is advantageously reduced, in relation with the tightening effect produced, thanks to connection means, for example articulation or guide means, dynamically "advantageous", as it is better described in the following. Therefore, such activation force can be easily applied by the same operator, without recurring to actuation means powered by external energy sources.

The command member 40 comprises, in particular, a base 41 , preferably having cylindrical shape. The base 41 can bear, for example a leverage 30 for the transmission of the above mentioned activation force, articulated to the first arm 24 and to the second arm 25.

More precisely, the leverage 30 can comprise a first lever member 31 and a second lever member 32, respectively articulated, at one end, to the first arm 24 and to the second arm 25 of the tightening member 2 and, at the opposite end, to a transversal articulation pin 33, in which the longitudinal axis is parallel to the cited transversal pin 23 and preferably coplanar to the same longitudinal axis A of the fastening device 1 .

The articulation pin 33 is carried fixed by the command member 40 to apply to the first arm 24 and to the second arm 25 of the tightening member 2, though the leverage 30, the activation force necessary to balance the resisting tightening force of the portion of filiform material which is intercepted by the first jaw 21 and by the second jaw 22.

In particular, one of the two lever members 31 , 32 can be split, and articulated to the articulation pin 33 from opposite sides with respect to the other lever member 31 , 32 (see figure 7).

The command member 40 is preferably fork shaped and, in particular, is inserted axially slidable inside the tubular casing 4. From the base 41 a couple of support prongs 42 axially extends towards the inside of the casing 4, between which the first arm 24 and the second arm 25 of the tightening member 2 are interposed (see figures 5 to 7).

The support prongs 42 comprise as well guide means 43 represented by slots, predisposed to receive sliding the cited transversal pin 23 axially fixed with respect to the casing 4. Each slot 43 has as a matter of fact an elongated extension in axial direction A. [99] The activation assembly 3 comprises as well a connection member 44 applied or integrally obtained on the base 41 by the side addressed towards the outside of the device 1 , to allow an easy and fast connection with outer actuation means, for example a screw tool of known type, electrically or pneumatic powered.

[100] Different further kinds of actuation means can be connected with the above mentioned connection member 44, provided that they are suitable for the scope of producing the rotation of the tightening member 2 connected to the base 41 of the command member 40, as it is described in more detail in the following.

[101 ] Preferably, the connection member 44 has the shape of a shank, advantageously of normalized type, predisposed for the removable connection with actuation means of known type, to command the rotation of the operative members contained inside the casing 4.

[102] In substance, providing the connection member 44 allows to connect the fastening device 1 in a very versatile way with any actuation means, independently from the power source, for example electric, pneumatic, or other kind, portable or fixed.

[103] The shank 44 can be for example cylindrical, to be tightened on a mandrel of a tool, or square to transmit the rotation without tightening.

[104] At the command member 40, the casing 4 preferably comprises a guide sleeve 50, inside which the base 41 is inserted axially sliding and rotatable with respect to the same axis A. More precisely, the guide sleeve 50 is axially associated with an end portion of the casing 4, opposite to the opening 6 for the insertion of the portion of filiform material to fasten.

[105] Therefore, the base 41 can shift inside the guide sleeve 50 according to an activation direction, coinciding with the above mentioned axis A.

[106] The base 41 is mobile in the above mentioned activation direction alternatively between a rest condition, for example extracted with respect to the guide sleeve 50, at which the leverage 30 carries the tightening member 2 in inactive opening configuration (see figure 5), and an operative condition, for example fed inside the guide sleeve 50, at which the leverage 30 operates the tightening member 2 in operative closure configuration (see figure 6).

[107] Moreover, the base 41 of the command member 40 can rotate about the same axis A upon command of the above mentioned actuation means, when these are connected with the connection member 44. Such rotation allows to twist a portion of filiform material about the same axis A when this is tightened by the jaws 21 , 22 of the tightening member 2, so as to carry out the desired fastening with a determined tightening rate.

[108] In order to allow such freedom degree, the casing 4 can be drawn in rotation together with the tightening member 2, or it can stay stationary with respect to the same rotation, as it is the case illustrated in figures 1 to 8. [109] In this case, for example the transversal pin 23 of articulation of the tightening member 2 is fixed to a sleeve 45 mounted coaxial to the casing 4 and fixed axially thereto, through suitable fixing rings 46. The same sleeve 45 is fixed to the casing 4 through the interposition of revolving support means 47. In this way, the actuation means connected with the connection member 44 can draw in rotation the tightening member 2 carrying the transversal pin 23, so producing the fastening and the tightening desired of the filiform material to the fastening zone. Due to the presence of revolving support means 47, at the same time, the casing 4 is not drawn in rotation, making safer the handling of the tool by the operator.

[1 10] The functioning of the fastening device for filiform metal materials and similar products according to the invention can be understood from the preceding description.

[1 1 1 ] In a starting preparation step, the fastening device 1 is connected with actuation means, for example a portable screw gun of the known type, electrically powered, through the connection member 44.

[1 12] At the fastening zone, for example the overlapping zone of the longitudinal and transversal elements of a metal net to be manufactured, a first crop of filiform material is placed, for example a U-shaped metal wire.

[1 13] The protruding ends of such crop protrude therefore from one operative side, at which the fastening device 1 is brought. The free portions of the wire can protrude from the operative side with any orientation and with any longitudinal extent, even not equal, of the branches of the U-shape.

[1 14] Then, the fastening device 1 is brought at such fastening zone, so as to be able to receive the protruding ends of the fastening wire inside the opening 6 obtained at the top of the inlet portion 5 of the casing 4. The preferably funnel shape of the opening 6 eases the centring and ensures the correct insertion of the wire, accompanying the protruding ends inside the inlet portion 5, independently from the respective starting orientation.

[1 15] In practice, the inlet portion 5 is approached to the fastening zone, centring the protruding portions of wire, until bringing the annular rim 7 in abutment against the fastening zone itself. In this step, the tightening member 2 has the fist jaw 21 and the second jaw 22 in the cited inactive opening configuration, predisposed to receive the the wire portion or ends to tighten at a height substantially below the opening 6.

[1 16] The activation assembly 3 is the operated to exert the activation force necessary to tighten the wire ends inserted inside the opening 6, that is which can be intercepted by the jaws 21 , 22.

[1 17] In practice, the command member 40 is moved in the activation direction, coinciding in the illustrated case with the direction of the longitudinal axis A. [1 18] In particular, the base 41 can be pushed from the extracted configuration to the fed configuration into the guide sleeve 50. Such displacement moves the leverage 30 of articulation to the tightening member 2, thus bringing the first jaw 21 and the second jaw 22 from the inactive opening configuration to the operative closure configuration. The wire portion or ends previously inserted inside the opening 6 are then intercepted by the first jaw 21 and by the second jaw 22, and tightened with a tightening force depending on the activation force applied to the base 41 .

[1 19] In substance, for example, the activation assembly 3 is pushed by the operator, while such push is efficiently contrasted by the abutment of the rim 7 against the fastening zone.

[120] More generally, it is in fact sufficient that the operator connects a portable tool having an end mandrel, to the fastening device 1 . The operator must then simply exert the activation force in the direction of the axis of the mandrel, against the fastening zone, to tighten the portion or the wire ends intercepted through the first jaw 21 and the second jaw 22.

[121 ] Such activation force, could be, as an alternative, a traction, instead of a compression, or a force applied in a different direction.

[122] At this point, it is possible to carry out the fastening, by operating the rotation of the actuation means of the tool previously connected to the fastening device 1 , through the shank 44.

[123] The above mentioned rotation draws in rotation the tightening member 2 and, consequently, the portion or the ends of the fastening wire held and tightened between the first jaw 21 and the second jaw 22. The portion of the above mentioned ends are then progressively twisted about the rotation axis A until completion of the fastening, up to the desired tensioning rate.

[124] The aforesaid functions of limitation of the torque and of percussion, previously cited, can be used to give the fastening a stronger or lesser pretension also in relation to the diameter of the filiform material used for the fastening.

[125] Once completed the fastening, it is sufficient to stop the rotation of the activation portable tool, in order to carry out the subsequent fastening on a respective fastening zone.

[126] In figures 9 to 13 a second embodiment of the invention is shown, in which the fastening device 1 has technical features entirely similar, from a structural as well as functional point of view, to those described for the first embodiment. More precisely, for this second embodiment and for the further embodiments described in the following, the technical features which have a similar structural an functional shape have been indicated with the same reference numbers.

[127] It is necessary to underline that in this further embodiment a different relation is provided between the longitudinal extent of the first jaw 21 and of the second jaw 22 with respect to the longitudinal extent respectively of the first arm 24 and of the second arm 25 of the tightening member 2, as well as of the activation leverage 30. By adjusting such relation, it is possible to produce a tightening force correspondently increased on the first jaw 21 and on the second jaw 22, exploiting, in particular, the principle of operation of the first-class levers.

[128] More precisely, to produce such effect, the fastening device has the first arm 24, the second arm 25 and possibly the operating leverage 30 with longitudinal extent increased in corresponding manner, with respect to the previously described embodiment.

[129] The casing 4 has, to this purpose, a containment portion 4' with an increased diameter with respect, for example, to the inlet portion 5, so as to contain the pantographic articulation motion, of the arms 24, 25 and of the leverage 30. In practice, the containment portion 4', preferably having as well cylindrical shape, is sized so as to allow the first arm 24 and the second arm 25 to tilt from the inactive opening position to the operative closure position of the jaws 21 , 22.

[130] In particular, in figure 9 are schematized the configurations taken by the first arm 24 in the inactive opening configuration 24a approached to the axis A and in the operative closure configuration 24b turned towards the inner wall of the containment portion 4' of the casing 4.

[131 ] Unlike the previously described embodiment, the command member 40' can have in this case a first sleeve 51 and a second coaxial sleeve 52, associated with the base member 41 carrying the connection member 44.

[132] The first sleeve 51 , in particular, is inserted axially sliding and rotatable inside the containment portion 4' and of the guide sleeve 50, to guide the operation of the tightening member 2, while the second sleeve 52, arranged inside the first sleeve 51 , carries the articulation to the articulation pin 33, with the same functions previously described. In order to allow the opening and the closure of the leverages engaged by the aforesaid activation, it is possible to provide that the first sleeve 51 comprises diametrically opposite peripheral notches 53.

[133] Finally, it should be observed that, in order to lighten the fastening device 1 , the provided leverages can have an overall reduced cross-section, compatibly with the endurance and the dynamic steadiness of the members subjected to motion. For example, it is possible to provide that the different levers which form the tightening member 2 are split, to reduce the overall cross-section, and that they are arranged in perfectly symmetrical way to allow the articulation and the steadiness of the different components (see figure 10).

[134] The functioning of the described second embodiment is entirely similar to that previously described of the first embodiment.

[135] A third embodiment is shown in figures 14 to 18. [136] This embodiment has technical features functionally similar to those already described, excepting the fact that the leverage 30' has a double pivot with the command member 40. More precisely, each lever member 31', 32' is articulated to a respective articulation pin 33' fixed in distal position to a suitable stirrup 48 fixed to the base 41 of the command member 40.

[137] Moreover, the first lever member 31' and the second lever member 32' have arc-shape, and are arranged in symmetrical way with respect to the axis A, to reduce the space required by the articulation of all the involved parts, for the opening (see figure 14) and the closure (see figure 15) of the tightening member 2. It allows to reduce the transversal space required by the fastening devicel , keeping for example a cylindrical shape having substantially constant cross-section, for the whole longitudinal length, being more comfortable for use.

[138] In the illustrated case, it is possible to observe that the inlet portion 5' is realized as a distinct component with respect to the casing 4, of covering.

[139] More precisely, such inlet portion 5' comprises a fixing rim 49 locked in removable way through fixing rings 54 in a suitable housing seat obtained inside the casing 4. This eases the assembling and the accessibility of the operative members inside the same casing 4.

Obviously, it is possible to provide as an alternative that the inlet portion is realized in a single piece or in the shape illustrated for the other embodiments.

[140] The functioning of the third embodiment described is entirely similar to the functioning previously described for the other embodiments.

[141 ] A fourth embodiment, very similar, from the structural and functional point of view to the embodiment shown in figures 14 to 18 is shown instead in figures 19 to 21 .

[142] The technical features of the disclosed fastening device have articulation members, in particular the first lever member 31 " and the second lever member 32", the first arm 24" and the second arm 25", of rectilinear and more elongated shape, to generate a high tightening force, maintaining the operative members inside a casing 4 substantially with a constant cross-section.

[143] As said before, for each embodiment schematized in figures, it is possible to provide that the casing 4, 4' is rotatable together with the support sleeve 45 of the transversal pin 23, for example being realized in a single piece integral with the same sleeve, or fixed with respect to the rotating sleeve 45, through the interposition of revolving support means 47 or of equivalent elements.

[144] A fifth embodiment is illustrated in figures 22 to 27, in which the tightening member 2, for the rest entirely similar to what was previously described, has a transversal pin split in a couple of transversal pins 23' spaced from the axis A. [145] In practice, the first jaw 21 and the first arm 24, as the second jaw 22 and the second arm 25, are hinged to a respective transversal pin 23' spaced from the axis A. Providing such splitting of the articulation pivot 23' frees a channel 8 at the longitudinal axis A, accessible for the wire or for the fastening wires, when the tightening member 2 is in inactive opening configuration (see figures 22 and 23). The channel 8 enables wires of any extent to freely access, without obstacles, inside the opening 6, to be correctly tightened between the first jaw 21 and the second jaw 22. This provision can be associated with any described embodiment, giving rise to a functioning entirely similar to the already described.

[146] Actually, in a sixth embodiment shown in figures from 28 to 30, it can be seen the presence of the aforesaid couple of transversal pins 23', associated with a leverage 30 of command of the tightening member 2, articulated to the base 41 at a single pin 33.

[147] Like the previously described embodiment, the provision of a couple of transversal pins 23' shapes a free channel 8 between the jaws 21 , 22 of the tightening member 2 (see figure 30).

[148] Figures 31 , and 32 show instead in schematic manner a seventh embodiment of the fastening device 10, in which instead of the leverage 30 of command of the jaws 21 , 22, guide means are provided, for example cam means.

[149] In this case, the command of the jaws of the tightening member 2 occurs by causing the sliding of respective portions of the same jaws 21 , 22, through an axial operating push, onto the above mentioned guide means 300, to bring the tightening member alternatively from the inactive configuration (see figure 31 ) to the operative condition (see figure 32).

[150] Finally, figures 33 and 34 show an eighth embodiment of the fastening device 100, identified by the fact that the tightening means 200 are shaped by a first tightening blade 210 and by a second tightening blade 220, sliding in converging manner towards the opening 6, inside respective guides 300' realized inside the casing 400.

[151 ] The sliding of the blades 210, 220 for the tightening of a portion of filiform material entering through the opening 6, is operated, in a way entirely similar to the previously described ones, from the activation member 3, which is predisposed to intercept with its base 41 a portion of the same blades.

[152] As it can be understood from figures 33, 34, also in this case the tightening of a portion of filiform material intercepted occurs at a substantially fixed distance from the rim 7, thus creating, further to twisting about the longitudinal axis A the desired pretensioning of the fastening.

[153] For the remaining characteristics, the fastening device 100 is functionally entirely similar to the previously described ones.

[154] Figure 35, finally, shows a fastening obtained, in particular, with the fastening device according to the invention, in any embodiment. [155] The fastening comprises a portion B wound about the fastening zone and a twisted portion C of respective branches of the same fastening about the longitudinal fastening axis A.

[156] The fastening zone is for example represented by the crossed overlapping of a first bar E and of a second bar F.

[157] The particular obtained fastening has a wound portion B perfectly stretched about the fastening zone, adherent or tangent to the profile of the same. Moreover the twisted portion C is perfectly rectilinear and tensioned until plasticization, with a regular pitch up to the free end cut by the operative portion of the tightening member 2, partially indicated with a dotted line in figure 35.

[158] The particular fastening, perfectly stretched and smooth, is, in particular, obtained thanks to the use of the described fastening device, which ensures, in the twisting step, that is of rotation of the tightening member 2, a substantially constant distance D between the fastening zone and the tightened portion of filiform material.

[159] During the rotation, the activation portion of the device retains a portion of tightened filiform material, preventing sliding in direction of the longitudinal axis A. Moreover, when the tightened portion of filiform material opposes greater resistance to twisting due to an advanced twisting effect, the same operative portion slides in circumferential direction on the tightened portion of wire, engraving it so as to facilitate a net cut, which removes the end portion G.

[160] The obtained fastening is particularly advantageous since stretched and accurate, even operating with filiform metal material and the like, having a diameter greater than 0,8 mm.

[161 ] The fastening according to the invention can have diameter of the filiform material even up to 4 mm.

[162] In particular, the fastening according to the invention can be performed with filiform material of a diameter comprised between 0,8 mm and 4 mm, and therefore able to fasten in safe and pre-tensioned way very heavy fastening elements, such as reinforcement bars having a large diameter, for example a first bar or rod E having a diameter up to 60 mm with a second bar or rod F having a diameter up to 16 mm or 20 mm. The weight of the structure fastened in tensioned way can thus reach up to 6 tons.

[163] The fastening according to the invention is particularly advantageous for use in the construction field, being made with filiform material equal to or greater than 1 ,5 mm up to 3 mm. In this case, the fastening is safe and robust, also for particularly heavy applications.

[164] In any case, the fastening is tensioned, with the stretched portion B wrapped around the fastening zone (see figure 36), unlike the traditional known fastening in which the wound portion is substantially loose around the fastening zone and, consequently, the elements to be fastened are not firmly pushed together or pressed against one another. An example of such traditional fastenings is visible in figure 37, in which the different portions, for more clarity, are indicated by adding a superscript to the same letter that distinguishes corresponding portions, even in the respective structural and functional diversity, of the fastening according to the invention shown in figure 36.

[165] Moreover, it is important to highlight that thanks to the fastening, the elements E, F to fasten are firmly pushed together, thanks to the aforementioned tensioning of the wound portion B. Therefore the so constrained elements, such as rods, do not move when the fastened structure, for example the reinforcement, is handled or when the operators walk on it to carry out the assembling and the casting of the concrete.

[166] In practice, the embodiment of the invention, the materials used, as well as the shape and dimensions, may vary depending on the requirements.

[167] Should the technical characteristics mentioned in each claim be followed by reference signs, such reference signs were included strictly with the aim of enhancing the understanding the claims and hence they shall not be deemed restrictive in any manner whatsoever on the scope of each element identified for exemplifying purposes by such reference signs.

Claims

1 . Fastening device for metallic filiform materials and similar products, of the type comprising a tightening member (2) provided with a tightening operative portion (21 , 22, 210, 220) predisposed to perform the tightening of at least one portion of a said filiform material, wound at a fastening zone comprising at least one element to be fastened, and to carry out the fastening of said tightened portion of filiform material by twisting two respective branches of said portion about a fastening axis, characterized in that

it comprises a casing (4, 4', 400) bearing said tightening member (2) along a longitudinal axis (A) and having an inlet portion (5, 5') having an opening (6) about said longitudinal axis (A) for the insertion of said portion of filiform material to be tightened, and an abutment portion (7) for the abutment against said fastening zone, an activation assembly (3) slidable inside said casing (4, 4', 400) along said longitudinal axis (A), for applying an activation force to said tightening member (2) predisposed to move said operative portion (21 , 22, 210, 220) from a inactive configuration to an operative configuration of tightening in which said operative portion (21 , 22, 210, 220) performs the tightening of said portion of filiform material inserted through said opening (6) at said longitudinal axis (A) at a distance (D) substantially fixed with respect to said abutment portion (7) placed against said fastening zone, a connection member (44) for the connection with actuation means, for operating the rotation of said tightening member (2) about said longitudinal axis (A) and performing said fastening when said operative portion (21 , 22, 210, 220) is held in said operative tightening configuration, said inlet portion (5, 5') being arranged as a covering for said operative portion (21 , 22, 210, 220) both in said inactive configuration, leaving free said opening (6) for the insertion of said portion of filiform material to be tightened, and in said operative tightening configuration, to produce said fastening of said portion of filiform material, wound in tensioned way about said fastening zone and twisted in regular manner along said longitudinal fastening axis (A).

2. Fastening device according to claim 1 , characterized in that said activation force is applied through a push action by said activation assembly (3) to bring said abutment portion (7) in abutment against said fastening zone.

3. Fastening device according to claim 1 , characterized in that said activation force is applied through a traction force by said activation assembly (3) on said fastening zone.

4. Fastening device according to claim 2, characterized in that when said operative portion (21 , 22, 210, 220) of said tightening member (2) is in said operative tightening configuration , said operative portion (21 , 22, 210, 220) is in a condition of stable balance, therefore, upon reaching said operative configuration, said tightening member (2) autonomously remains in such configuration, also after removing the above mentioned activation force, used to bring said operative portion (21 , 22, 210, 220) from said inactive to said operative configuration.

5. Fastening device according to one of claims 1 to 4, characterized in that said connection member (44) is predisposed for a removable connection with said actuation means of said rotation.

6. Fastening device according to one of the previous claims, characterized in that said connection member (44) is of the shank type or of mandrel type, predisposed for the removable connection with a portable tool of activation of the rotation about said longitudinal axis (A).

7. Fastening device according to one of the previous claims, characterized in that said casing (4, 4', 400) is rotatable jointly with said tightening member (2) about said longitudinal axis (A) through the activation of said connected actuation means.

8. Fastening device according to one of the claims 1 to 7, characterized in that said casing (4, 4', 400) is associated with said tightening member (2) through the interposition of revolving support means (47), being fixed to said rotation of said tightening member (2), operated through said connection member (44).

9. Fastening device according to one of the previous claims, characterized in that said operative portion (21 , 22, 210, 220) of said tightening member (2) shapes sharp tightening ends intended to intercept said portion of filiform material, thus carrying out the tightening and preventing the axial sliding thereof.

10. Fastening device according to one of the previous claims, characterized in that said activation assembly (3) is made up of a command member (40) comprising a base (41 ), connected with said tightening member (2), at the side turned inwards to said casing (4) and bearing said connection member (44) at the opposite side.

1 1 . Fastening device according to one of the previous claims, characterized in that said abutment portion (7) shapes a rim (7) bounding said opening (6), predisposed to act as an abutment against the fastening zone.

12. Fastening device according to claim 1 1 , characterized in that said border (7) has a substantially flat surface orthogonal to said fastening longitudinal axis (A) or a surface having depressions predisposed to act as housings for the fastening zone.

13. Fastening device according to one of the previous claims, characterized in that said opening (6) has a flaring shape converging towards the inside of said casing (4, 4', 400), to ease the insertion of said portion of filiform material.

14. Fastening device according to one of the previous claims, characterized in that said tightening member (2) shapes a pliers or jaws member, said operative portion (21 , 22) being made by a first jaw (21 ) and by a second jaw (22) pivoted at a pin (23, 23') transversal to said longitudinal axis (A).

15. Fastening device according to claim 14, characterized in that said first jaw (21 ) and said second jaw (22) are respectively borne by a first arm (24) and by a second arm (25), said first arm (24) and said second arm (25) being connected with said activation assembly (3), said transversal pin (23, 23') being carried fixed in the direction of said longitudinal axis (A) with respect to said casing (4, 4').

16. Fastening device according to claim 15, characterized in that said first arm (24) and said second arm (25) are articulated to a leverage (30) for the transmission of said activation force applied by said activation assembly (3).

17. Fastening device according to claims 10 and 16, characterized in that said leverage (30) comprises a first lever member (31 ) articulated to said first arm (24) and a second lever member (32) articulated to said second arm (25), said first lever member (31 ) and said second lever member (32) being pivoted to said base (41 ) of said command member (40) at an articulation pin (33, 33') parallel to said transversal pin (23, 23').

18. Fastening device according to claim 17, characterized in that said articulation pin (33') is split so that each said lever member (31', 32') is articulated to a respective said articulation pin (33') fixed to a bracket (48) borne by said base (41) of said command member (40).

19. Fastening device according to claim 18, characterized in that said transversal pin is split in a couple of transversal pins (23') spaced out from said longitudinal axis (A), said first jaw (21 ) and said first arm (24), said second jaw (22) and said second arm (25) being hinged to said respective transversal pins (23'), so as to free a channel (8) at the same longitudinal axis (A), accessible by said portion of filiform material, when said operative portion (21 , 22) of said tightening member (2) is in said inactive configuration.

20. Fastening device according to one of the claims 1 to 14, characterized in that said first jaw (21 ) and said second jaw (22) are guided from said inactive configuration to said operative configuration through the sliding on guide means (300) of cam type, obtained inside said casing (4).

21 . Fastening device according to one of claims 1 to 13, characterized in that said tightening member (2) shapes a blades member, said operative portion (210, 220) being made by a first tightening blade (210) and by a second tightening blade (220), slidable in converging manner towards said opening (6), inside respective guides (300') obtained inside said casing (400).

22. Method of fastening a filiform material about a fastening zone comprising at least one element (E, F) to be fastened, characterized in that it comprises the following working steps:

a. prearranging at least one said filiform material about a said fastening zone; b. approaching a fastening device (1 , 100) to said fastening zone carrying said prearranged filiform material, so as to insert a portion of said prearranged filiform material through an opening (6) shaped by an inlet portion (5) of said fastening device (1 , 100), said opening (6) being placed about a longitudinal axis (A) of the same fastening device (1 , 100), said fastening device (1 , 100) comprising a casing (4, 4', 400) carrying a tightening member (2) along said longitudinal axis (A) with a tightening operative portion (21 , 22, 210, 220) prearranged in an inactive configuration, for receiving said portion of filiform material through said opening (6);

c. applying an activation force on said fastening device (1 , 100) by making slide along said longitudinal axis (A) an activation assembly (3) of said fastening device (1 , 100) with respect to said casing (4, 4', 400), so as to abut said fastening zone through an abutment portion (7) of said fastening device (1 , 100) and thus moving through the same activation force said tightening operative portion (21 , 22, 210, 220) of said tightening member (2) in an active configuration, thus performing the tightening of said inserted portion of filiform material;

d. operating the rotation of said tightening member (2) about said longitudinal axis (A) through actuation means connected with said tightening member (2), through a connection member (44) of said fastening device (1 , 100), and at the same time e. keeping the abutment of said abutment portion (7) against said fastening zone so as to obtain a tensioned fastening, the distance (D) between said abutment portion (7) and said operative portion (21 , 22, 210, 220) of said tightening member (2) being substantially fixed, when said operative portion (21 , 22, 210, 220) is operated in said operative configuration of tightening.

23. Method according to claim 22, characterized in that said activation force is a force of push against said fastening zone.

24. Method according to claim 22 or 23, characterized in that the step of (a.) prearranging a filiform material is associated with the further step of prearranging said fastening device (1 , 100) performing the removable connection with actuation means of the type of a portable tool, so as to produce the above mentioned rotation of said tightening member (2).

25. Method according to one of claims 22 to 24, characterized in that it comprises the further step of producing an effect of twisting vibration through said driving in rotation through said actuation means and, once a given torsion value is reached, said twisting vibration effect being predisposed to help the accuracy of the fastening.

26. Method according to one of claims 22 to 25, characterized in that it comprises the further step of producing a battering effect due to an axial stress which is alternated through said driving in rotation of said actuation means, said battering effect being predisposed to help the accuracy of the fastening.

27. Fastening of a filiform material about a fastening zone comprising at least one element (E, F) to be fastened, said fastening of filiform material comprising a portion (B) wound about the fastening zone and a twisted portion (C) of respective branches of the same fastening about a longitudinal fastening axis (A), characterized in that said said filiform material has a diameter higher than 0,8 mm, said wound potion (B) is tensioned about said fastening zone, so as to result to be adherent and/or tangent to the profile of said at least one element to be bound (E, F), and in that said twisted portion (C) is arranged tensioned along said fastening longitudinal axis (A), with a winding pitch being substantially regular.

28. Fastening according to claim 27, characterized in that said filiform material has a diameter comprised between 0,8 mm and 4 mm.

29. Fastening according to claim 28, characterized in that said filiform material has a diameter comprised between 1 ,5 mm and 3 mm.