WO2011045749A2

WO2011045749A2 - Extendable lockup system for belts and straps in general.

Info

Publication number: WO2011045749A2
Application number: PCT/IB2010/054620
Authority: WO
Inventors: Franco Buttignon
Original assignee: Franco Buttignon
Priority date: 2009-10-13
Filing date: 2010-10-12
Publication date: 2011-04-21
Also published as: ITPI20090124A1; WO2011045749A3; IT1396242B1

Abstract

The present invention concerns a belt or a strap for use in clothing, footwear, leather goods and other accessories in general comprising a belt 2 and a buckle 3 and characterized in that it comprises at least an elastic element (4, 204, 304, 404, 504, 604), elastically extendable/retractable between an extended position and a rest position. In such a manner, in correspondence of the application to the belt or strap of a traction Tsuperior to a minimum threshold value, the element lengthens elastically, causingan increase in the overall length of the belt or strap. Then, in correspondence of the traction it returns to the rest position, taking the belt back to the original measure.

Description

TITLE

EXTENDABLE LOCKUP SYSTEM FOR BELTS AND STRAPS IN GENERAL Technical Field

The present invention regards the technical field relative to belts and/or straps of different nature and that are commonly used in fields that go from the leather industry to footwear, clothing and other accessories.

In particular, the present invention refers to an innovative system constituted by elastically yielding elements that allow belts and straps in general to assume extensive variations.

Background Art

As it is well known from the state of the art, belts and straps are commonly used on diverse products of the leather industry, footwear, clothing and even on other accessories in general, such as watches.

The straps constitute the lockup system of bags, briefcases, suitcases, backpacks, watches and some models of footwear both for men and women. In the last ones, the strap substitutes or coexists with the more ordinary laces. Classic belts, as it is well known, are instead used with the aim of maintaining in a correct position different types of clothes, both for men and women, such as trousers, jeans, skirts, raincoats, overcoats, jackets and even night dresses. In addition, both the belt and the strap have become neat and refined accessories and apart from having a practical function, they can always be distinguished even more with the brands of important fashion designers to offer style, elegance and refinement to those who wear them.

Generically, the basic components that form a belt include a buckle and a belt that is connected to the buckle by means of seams or with equivalent lockup systems, such as those bayonet-like or through appropriate bolts and screws.

In the case of straps for bags, suitcases, shoes, watches and similar, the overall architecture is substantially equivalent, naturally with the exception of its dimensions (typically the length varies) . In the case of a suitcase, for example, the lockup strap is composed of two parts: the first with belt and buckle and a second with belt with holes. The first belt is connected on a wallet-like open/close face of the suitcase. The second one is connected on the opposite face of the suitcase in such a way that by inserting it into the buckle of the first one a closure is realized that prevents it from opening.

A very common technical problem in the field of the use of belts and straps concerns the variations of the volumes that they are destined to contain.

It is well known in fact that after a meal an increase (though contained) of the circumference of the waist occurs, which is essentially due to the physiologic dilation because of the consumption of food and/or drinks. When this happens, it is therefore inevitable to notice a certain feeling of tightness that calls the need for loosening the waist by unblocking the buckle.

Such a problem is particularly felt both by men and women, since in certain circumstances, it can create many inconveniences .

Likewise, it may happen that the pre-established arrangement of the holes of the belt is such as not to allow a fastening at the desired measure. In that case, the user is obliged to choose either a constrictive or, alternatively, a slack position.

In the case of bags, briefcases, backpacks or suitcases, the problem is the same since in case of excessive filling it will be extremely difficult to operate their closing.

In the case of shoes or watches, the problem is equivalent as well. Just to think of a momentary swelling that causes the tightness of the instep or of a dilation of the wrist due to particularly hot environment conditions .

In GB 179486 a belt provided with springs so as to vary its length is described. Such a constructive solution presents springs that are directly in sight and does not result aesthetically appreciable. Moreover, the springs, being directly in sight, are exposed to the exterior, causing the risk of entanglement of the same with parts of clothing, and therefore of malfunctioning.

In US2004083536, on the other hand, the elastic element 4 is internally arranged in a sliding seat 21 but the overall configuration is such that the buckle cannot be separated from the rest of the belt.

Disclosure of invention

It is therefore the aim of the present invention to provide a new type of belt or strap in general, which can be used in the field of clothing, leather goods, footwear, accessories and other that solves at least in part the above mentioned inconveniences.

In particular, it is the aim of the present invention to provide a belt or strap wherein an elastic element is comprised that results easily exchangeable with respect to just the belt of the belt or with respect to both belt and buckle but that, at the same time, does not cause the risk of entanglement, avoiding the exposure in sight of the springs .

It is also the aim of the present invention to provide a belt and strap wherein the technical solution of the elastic element is such as to lend itself well to different constructive solutions wherein the aesthetic forms result appreciable and such as to adapt to the different models of buckle commonly used.

These and other aims are obtained with the present belt or strap for use in clothing, footwear, leather goods and accessories comprising a belt (2) and a buckle (3) wherein an elastic element (204, 304, 404, 604) results interposed between the belt (2) and the buckle (3) in such a way that the belt results selectively extendable/retractable, as per claim 1.

In accordance with the invention, the elastic element is directly connected to an end of the buckle in an exchangeable manner and comprises a sliding guide (208, 308, 408, 508, 608) inside of which one or more than one elastic springs (210; 310'; 310''; 410) are arranged for realizing selectively the elastic lengthening and in which the buckle is connected to the elastic element.

In such a manner, the buckle is not any more permanently connected to the elastic element but can easily be substituted by other ones. In addition, the springs are not in sight anymore, and therefore there is no risk of entanglement of the same with the clothes.

Advantageously, in accordance with a possible embodiment of the belt or the strap, the elastic element (204) can comprise:

- A first attachment to the belt on one side and a second attachment to the buckle on the opposite side;

- The sliding guide (208), generally box-shaped, into which a substantially U-shaped support (209) is generally arranged slidingly, comprising a front traverse (212);

- One or more than one traction springs (210) that are connected by one of their ends to the front traverse (212) and by the opposite end to the base (214) of the said sliding guide;

- and wherein the buckle is connected directly to the sliding support (209) . Advantageously, in another constructive solution of the belt or the strap in question, the elastic element (304) can comprise:

- The sliding guide (308), generally box-shaped, provided with a front traverse (308') and into which a support (309), generally rectangular or quadrangular, results slidingly arranged comprising a back traverse (312');

- One or more than one compression springs (310';

310'') that are connected on one side to the back traverse (312') of the sliding support (309) and on the opposite side to the front traverse (308') of the guide to which an end of the said one or more than one springs is connected and in which the said sliding guide (308) comprises a front traverse (308') to which the opposite end of the said one or more than one springs are connected, and wherein the buckle is directly connected to the sliding support (309) .

Advantageously, in a further descriptive configuration, the belt or the strap can comprise an elastic element (404) wherein the following are comprised:

- One or more than one traction springs (410);

- The sliding guide, substantially U-shaped (408);

A support (409) mounted in a sliding manner with respect to the guide and substantially U-shaped;

and wherein an adjustable traverse (408'') that is connected to the sliding guide (408) is comprised so as to form an adjustable anchorage base for the said springs on one side and wherein the opposite side of the springs is connected to the said support (409), and wherein the buckle is connected directly to the sliding support (409) .

Alternatively, in an advantageous manner, the belt or the strap can comprise an elastic element (504) comprising :

- A first (508) and a second corridor (508) obtained into the two arms (508') of the buckle of substantially annular shape ;

- A transversal support (509) that connects transversally the two arms (508') of the annular buckle and mounted slidingly by its ends along the first and the second corridor, the said support (509) comprises on one side an attachment (505) to the belt;

- A spring (510) arranged each one respectively into the first and the second corridor and connected by an end to the base of the said corridor and by the opposite end to the end of the transversal support (509);

- and wherein the springs are connected in a detachable manner to the corridor.

Last, in an advantageous manner, the said belt or strap can comprise an elastic element (604) comprising:

- The fixed sliding guide (608) to which the buckle is connected and into which an extractable element (609) provided with a pivot to spear the belt;

- A spring connected into the sliding guide to the extractable element;

- and wherein the spring is calibrated in such a way that the maximum extraction of the element (609) with respect to the sliding guide results such that the element remains into the external perimeter delimiting the overall area of the buckle.

In all the described configurations, advantageously, the buckle of the belt can further comprise means (620) through which to connect in an exchangeable manner a cover (621) to the buckle.

It is also described here, advantageously, an elastic element (204, 304, 404, 504, 604) comprising a first attachment to be connected to the belt of a belt or strap on one side and a second attachment to be connected directly to a buckle (3) of the belt on the opposite side and wherein the said attachments are configured in such a way that the elastic element results interposable between belt and buckle in an exchangeable manner and, further, comprises a sliding guide (208, 308, 408, 508, 608) into which one or more than one elastic springs are arranged inside it for realizing selectively the said retractable extension/retraction.

Advantageously, the said elastic element (204) can comprise in a possible solution:

- A sliding guide (208), generally box-shaped, into which a substantially U-shaped support (209) is arranged slidingly, comprising a front traverse (212);

- One or more than one traction springs (210) that are connected by one of their ends to the front traverse (212) and by the opposite end to the base (214) of the said sliding guide.

Alternatively, in an advantageous manner, the elastic element can comprise:

- A sliding guide (308), generally box-shaped, provided with a front traverse (308') and into which a support (309), generally rectangular or quadrangular, results arranged slidingly, comprising a back traverse (312');

- One or more than one compression springs (310'; 310'') that are connected on one side to the back traverse (312') of the sliding support (309) and on the opposite side to the front traverse (308') of the guide to which an end of the said one or more than one springs are connected and wherein the said sliding guide (308) comprises a front traverse (308') to which the opposite end of the said one or more springs are connected.

Advantageously, in a further embodiment, the elastic element (404) can comprise:

- One or more than one traction springs (410);

- A sliding guide (408), substantially U-shaped;

- A support (409) mounted slidingly with respect to the guide and substantially U-shaped;

and wherein an adjustable traverse (408'') is comprised that is connected to the sliding guide (408) so as to form an adjustable anchorage base for the said springs on one side and wherein the opposite side of the springs is connected to the said support (409) .

Advantageously, the elastic element (504) can eventually comprise:

- A first (508) and a second corridor (508) obtained into the two arms (508') of the buckle, substantially annular;

- A transversal support (509) that connects transversally to the two arms (508') of the annular buckle and mounted slidingly by its ends along the first and the second corridor, the said support (509) comprising on one side an attachment (505) to the belt;

- and wherein the springs are connected in a detachable manner from the corridor.

In a last possible embodiment, advantageously, the elastic element (604) can comprise:

- A fixed sliding guide (608) to which the buckle of the belt results connectable and into which an extractable element (609) slides provided with a pivot to spear the belt of the belt;

- A spring connected to the sliding element on one side and to the extractable element on the other side; - and wherein, further, the spring is calibrated in such a way that the maximum extraction of the element (609) with respect to the sliding guide is such that the element remains inside the external perimeter delimiting the overall area of the buckle.

Brief description of drawings

Further characteristics and advantages of the extendable belt or strap, according to the invention, will be clearer with the description of some of its embodiments that follows, made to illustrate but not to limit, and with reference to the annexed drawings, wherein:

- Figure 1 shows a belt or strap in accordance with a first possible embodiment of the invention;

- Figure 2 shows a lateral view of the same;

- Figure 3 shows, both a lateral view and a top view of the belt or strap wherein the elastic element results extended by means of the traction applied and in a phase in which it results retracted in correspondence of the traction release.

- Figure 4 shows a second preferred embodiment of the invention ;

- Figure 5 shows in axonometry a detail of the components that form the elastic element 204.

- Figure 6 and figure 7 show an alternative embodiment that uses compression springs;

- Figures from 8 to 10 describe a further preferred embodiment of the invention with an adjustable elastic element ;

- Figure 11 and figure 12 show another possible embodiment of the invention wherein the springs are arranged directly into the buckle, while figure 13 shows, in accordance with such a solution, a different form of buckle ;

- Figure 14 and figure 15 show another embodiment wherein the pivot inserted into the hole of the belt, when it is extracted elastically, remains covered into the external perimeter of the buckle itself.

- Figure 16 shows exchangeable covers applicable to the buckles, while figure 17 shows examples of buckles configured to result connectable in an exchangeable manner to the elastic element.

- Figures 18 and 19 show the application of an elastic element between two subsequent portions of belt together with other further embodiments of elastic elements in general .

Description of some preferred embodiments

With reference to the annexed figures, a belt or strap is described in accordance with the present invention and comprising a belt 2 and a buckle 3. In particular, an elastic element is comprised which can result elastically lengthened in correspondence of a traction T applied so as to increase the overall length of the belt or strap, to then return to the rest condition in correspondence of the diminution or removal of the traction.

With particular reference to figure 1, a first embodiment of the invention is described which results particularly simple from the constructive point of view. In particular, an elastic element 4 results interposed between the belt 2 and the buckle 3. As better highlighted in figure 2 and in figure 3, the elastic element 4 is in that case constituted by rigid bands 6 (for example metal ones) placed side by side one to the other through an elastic-band joint 7. Figure 3 further indicates, both in a lateral view and in a top view, the effect of lengthening of the belt made possible through the lengthening of the elastic element 4. This takes place in the moment in which a traction T is applied on the belt that exceeds a predetermined threshold value, on the basis of the dimensional and elastic characteristics of the element 4 itself. The connecting methods of the elastic element 4 between belt and buckle are multiple. For example, figure 2 shows a bayonet-like attachment 5 arranged in correspondence of the band 4 on the opposite side to the attachment with the buckle 3. In such a manner, by simply inserting the head 2 ' ' of the belt 2 into the clutch 5 the block is realized. Nevertheless, equivalent systems, such as screws or seams, can be used without for this moving away from the present inventive concept .

It is also evident that the solution described above can be easily substituted by the use of a simple elastic band interposed between belt and buckle, and without for this moving away from the present inventive concept.

Figure 4 shows a second embodiment of the invention wherein an elastic element 204 is always described interposed between belt and buckle. In that case, the element 204 comprises a sliding guide 208 (visible in the tear view), generally box-shaped, into which a support 209 is mounted slidingly and to which one or more than one springs 210 are connected.

Going into the descriptive detail, the support 209 is realized through two parallel legs 211 and a front traverse 212 interposed between the legs in such a way as to define a substantially U-shaped element. The support 209 is therefore configured in such a way that the two legs 211 are sliding with respect to the guide 208. Figure 5 shows in axonometry the sliding guide 208 to which the support 209 is coupled.

The transversal dimension h of the traverse 212 is such as to be able to apply along the length of the same one or more than one traction springs, fixed through screws 213 or equivalent connecting elements. The springs (see for that purpose figure 4 and figure 5) result connected to the base 214 of the box forming the sliding guide on the opposite side of the traverse 212.

The same solution can anyway comprise springs of different nature, for example compression springs. To that aim, subsequent figure 6 and figure 7 show a third configuration that uses such types of springs.

In particular, figure 6 shows springs 310' of the bayonet-like type that exerts a compression force, while figure 7 shows simple linear compression springs 310''. In accordance with such a constructive solution, it is therefore necessary to include an adequate sliding support 309 and an adequate guide 308. In that sense, the external box-like guide 308 comprises a front traverse 308' to which to connect an end of the one or more than one present springs 310' or 310'', while the support 309 comprises a back traverse 312' to which to connect the opposite end of the one or more than one springs so that they work with compression when the belt is placed in traction T.

In that sense, an optimal configuration of the support 309 could be of the annular type, quadrangular or rectangular .

The subsequent figures from 8 to 10 show a fourth preferred embodiment of the invention. In this case, the elastic element 404 comprises a box-like sliding guide 408 into which the U-shaped support 409 is inserted for the springs. An adjustable traverse 408'' is connected to the sliding guide on the base of the box through screws, so as to form an adjustable anchorage base for the springs. By appropriately adjusting such screws the distance of the traction or compression springs can be varied. The opposite part of the springs is connected instead to the U-shaped support 409. The sliding element comprises a slot 405 through which the head of the belt results connectable. Figure 10 in fact shows a connection between belt and elastic element through ordinary screws, winding the head of the belt around the slot.

A further fifth preferred embodiment of the invention is described in the subsequent figures 11 and 12. In this case, the elastic element 504 is practically arranged into the buckle itself. In particular, a sliding guide 508 is obtained directly in the annular buckle (for example quadrangular, circular or rectangular) , incising in it two corridors 508 in correspondence of the two legs 508' into which the springs 510 are held (either traction or compression ones) . An end of the springs is connected to the base of the corridor, while the opposite end is connected to a support 509 comprising a slot or a bayonet^¬ like attachment 505 to be connected to the belt 2. Figure 12 shows a functioning phase in correspondence of the application of a traction T . In particular, it can be seen how the traction T determines a lengthening of the springs into their corridors.

The connection of the springs into the corridor is naturally of the removable type so that the buckle results separable from the belt.

Figure 13 shows a further constructive example of such a solution.

Figure 14 and figure 15 show a further preferred embodiment of the invention wherein an external sliding guide 608 forms a fixed channel having an end connectable to the belt. Into the channel an extractable sliding element 609 is arranged, in such a way that this can be extracted from the channel from the opposite side to the connection with the belt.

The extractable element comprises a pivot to spear the belt in the specific hole.

In such a configuration, the maximum extraction of the element 609 with respect to the sliding guide is such that the element remains into the external perimeter delimiting the overall area of the buckle.

In this way, the aesthetic effect is optimal since the extraction is anyway hidden by the buckle itself. Figure 15 shows such an extraction covered by the buckle.

In all the configuration described, the buckle can be configured in such a way as to result easily exchangeable with respect to the elastic element to which it is connected and, naturally, with respect to the belt. This gives the possibility of modifying it at will on the basis of personal likes.

In particular, the elastic element can comprise in all these embodiments a first attachment that allows to connect the belt to the elastic element itself on one side (for example through the slot 405 or removable screws) and on the opposite side a second attachment through which to connect the buckle in a removable manner. The second attachment can comprise screws or the elastic release of the legs themselves of the buckle provided with pivots that are inserted on the sides of the elastic element (such as in the solution shown in figure 10) .

The particular embodiment of figure 11 and 12 can also be realized in such a way that the springs 508 are fixed in the corridor and therefore not separable from the buckle .

Moreover, in all the embodiments described and independently from the fact that the buckle itself is detachable or not from the elastic element, the buckle can be substituted by a sort of cover-holder support and comprising holdings 620, for example holes into which release pivots engage. In such a manner, a cover 621 can be applied in a removable manner, allowing each time an easy substitution of the same (see figure 14) . This last embodiment, independently from the type of extendable system applied, favours very interesting production economy for the production company, thanks to the frontal decorative covers, easily applicable and replaceable. In such a manner, it will be very simple and economical to produce a greater variety of models, of any shape and design, to enrich the collection and offer the client broader choice.

In all the described embodiments, the elastic element used can be arranged in different points and not just exclusively between buckle and belt. The subsequent figure 15 shows, just for exemplification purposes, a generic elastic element, for example number 4, interposed along the belt, thus functioning as a joint between two subsequent portions. The subsequent figure 16 shows a further possible variety of elastic elements that can be used for the purpose (that is applicable between portions of belt and/or between belt and buckle) . Such a solution is particularly advantageous since it allows to use the production waste by realizing reduced portions of belt, to subsequently join through the interposition of elastic elements .

It is evident that, in accordance with what has been described, more than one elastic element can be comprised along the belt, thus joining more portions one to each other and eventually placing the said element in combination with an elastic element interposed between belt and buckle.

Having structurally described the basic elements of the invention, we now pass onto the description of the functionality with particular reference, just for descriptive simplicity purposes, just to the configuration of figure 2 and 3. Such functional description is naturally to be understood anyway extended and equivalent to all the other embodiments described.

In use, therefore, in correspondence of a traction T that exceeds a minimum threshold value on the basis of the springs used, the buckle starts to move away from the head 2 ' ' of the belt. Just for exemplification purposes and in an absolutely non limiting manner, figure 3 shows a lengthening dx of the elastic element 4 due to a predetermined traction T . The release of the traction T naturally translates in a return to the initial rest condition, as per figure 2. The realization of a belt or strap thus configured, therefore, allows to compensate the momentary variations of the waist or volumes in general that cause a certain state of traction on the belt itself.

It is evident that the term buckle used in the present text includes buckles of any nature and therefore release mechanic buckles as well as traditional pivot ones .

The present invention, by making reference to belts in general, is therefore also addressed to safety belts.

Claims

1. A belt or a strap for use in clothing, footwear, leather goods and other accessories in general comprising a belt (2) and a buckle (3) and comprising an elastic element (204, 304, 404, 504, 604) interposed between the belt (2) and the buckle (3) in such a way that the belt results selectively extendable/retractable and characterized in that the elastic element is directly connected to an end of the buckle in a detachable manner so that the buckle results exchangeable and further comprises a sliding guide (208, 308, 408, 508, 608) inside of which one or more than one elastic springs are arranged (210; 310'; 310''; 410; 510) to realize selectively the said elastic lengthening.

2. Belt or strap, as claimed in claim 1, wherein the said elastic element (204) comprises:

- The sliding guide (208), generally box-shaped, into which a support (209), substantially U-shaped, is slidingly arranged, comprising a front traverse (212);

- and wherein the buckle is connected directly to the sliding support (209).

3. Belt or strap, as claimed in claim 1, wherein the said elastic element (304) comprises:

- A first attachment to the belt on one side and a second attachment to the buckle on the opposite side; - The sliding guide (308), generally box-shaped, provided with a front traverse (308') and into which a support (309), generally rectangular or quadrangular, results arranged slidingly comprising a back traverse (312' ) ;

- One or more than one compression springs (310'; 310'') that are connected on one side to the back traverse (312') of the sliding support (309) and on the opposite side to the front traverse (308') of the guide to which an end of the said one or more than one springs is connected and in which the said sliding guide (308) comprises a front traverse (308') to which the opposite end of the said one or more than one springs are connected.

- and wherein the buckle is connected directly to the sliding support (309).

Belt or strap, as claimed in claim 1, wherein the said elastic element (404) comprises:

- One or more than one traction springs (410);

- The sliding guide (408), substantially U-shaped;

and wherein an adjustable traverse (408'') is comprised that is connected to the sliding guide (408) in such a way as to form an adjustable anchorage base for the said springs on one side and wherein the opposite side of the springs is connected to the said support (409)

- and wherein the buckle is connected directly to the sliding support (409);

Belt or strap, as claimed in claim 1, wherein the said elastic element (504) comprises:

- A first (508) and a second corridor (508) obtained into the two arms (508') of the substantially annular buckle ;

- A transversal support (509) that connects transversally the two arms (508') of the annular buckle and mounted slidingly by its ends along the first and the second corridor, the said support (509) comprising on one side an attachment (505) to the belt ;

- A spring (510) arranged each one respectively into the first and the second corridor and connected by an end to the base of the said corridor and by the opposite end to the end of the transversal support (509) ;

- and wherein the springs are connected in a detachable manner to the corridor.

6. Belt or strap, as claimed in claim 1, wherein the said elastic element (604) comprises:

- The fixed sliding guide (608) to which the buckle is connected and into which an extractable element (609) slides provided with a pivot to spear the belt;

- A spring connected into the sliding guide to the extractable element;

7. Belt or strap, as claimed in one or more of the preceding claims, wherein the buckle further comprises means (620) through which to connect in an exchangeable manner a cover (621) to the buckle.

8. An elastic element (204, 304, 404, 504, 604) comprising a first attachment to be connected to the belt of a belt or strap on one side and a second attachment to be connected directly to a buckle (3) of the belt on the opposite side and characterized in that the said attachments are configured in such a way that the elastic element results interposable between belt and buckle in an exchangeable manner and, further, it comprises an external sliding guide (208, 308, 408, 508, 608) into which one or more than one elastic springs are arranged to realize selectively the said retractable extension/retraction.

9. An elastic element (4, 204, 304, 404, 504, 604), as claimed in claim 8, wherein the said elastic element (204) comprises:

- A sliding guide (208), generally box-shaped, into which a substantially U-shaped support (209) is slidingly arranged comprising a front traverse (212);

10. An elastic element (204, 304, 404, 504, 604), as claimed in claim 8, wherein the elastic element comprises :

- A sliding guide (308), generally box-shaped, provided with a front traverse (308') and into which a support (309), generally rectangular or quadrangular, results slidingly arranged comprising a back traverse (312' ) ;

- One or more than one compression springs (310'; 310'') that are connected on one side to the back traverse (312') of the sliding support (309) and on the opposite side to the front traverse (308') of the guide to which an end of the said one or more than one springs is connected and wherein the said sliding guide (308) comprises a front traverse (308') to which the opposite end of the said one or more than one springs are connected.

11. An elastic element (204, 304, 404, 504, 604), as claimed in claim 8, wherein the elastic element (404) comprises :

- One or more than one traction springs (410);

- A sliding guide (408), substantially U-shaped;

and wherein an adjustable traverse (408'') is connected to the sliding guide (408) in such a way as to form an adjustable anchorage base for the said springs on one side and wherein the opposite side of the springs is connected to the said support (409) .

12. An elastic element (204, 304, 404, 504, 604), as claimed in claim 8, comprising:

- A first (508) and a second corridor (508) obtained into the two arms (508') of the buckle, substantially annular ;

- A spring (510) arranged each one respectively into the first and the second corridor and connected by an end to the base of the said corridor and by the opposite end to the end of the transversal support

(509) ;

- and wherein the springs are connected in a detachable manner from the corridor. 13. An elastic element (204, 304, 404, 504, 604), as claimed in claim 8, wherein the elastic element (604) comprises :

- A spring connected to the sliding element on one side and to the extractable element on the other side;

- and wherein, further, the spring is calibrated in such a way that the maximum extraction of the element (609) with respect to the sliding guide is such that the element remains inside the external perimeter delimiting the overall area of the buckle.