TECHNICAL FIELD

The present invention generally relates to buttons for garments mainly made of jeans fabric, and particularly relates to removable nail buttons.

BACKGROUND ART

Buttons have been used since prehistoric times to fix together the edges of a garment. Over time they have been declined in various shapes and structures to fulfill a range of needs as well as variable fashion trends.

For the purposes of the present invention, a relevant type is represented by the so-called "nail buttons", which are also named "stem buttons" due to their characteristic mushroom-like shape, or simply "jeans buttons" as they find preferential, but not exclusive, application on garments made of jeans fabric. In these kind of buttons, the head to be inserted into the buttonhole made on a flap of fabric, protrudes from a stem which is firmly fixed to the other flap of the fabric to be buttoned by means of a nail which is an integral part of the button.

As the enclosed Figure 1 illustrates, a nail button of the known type generally consists of a male component, substantially having the shape of a nail provided with circular claws, and a female component comprising a head from which a cylindrical hollow stem protrudes.

By placing the fabric between the two components, and using special manual pliers or automatic machines (e.g. a punching machine), the sharp tip of the male component punches the fabric and enters the axial hole where it is held by the claws. Since the nail undergoes an irreversible plastic deformation, the male and the female component are permanently joined and the button is firmly fixed to the garment.

We point out that this male component is commonly called a "threaded nail" even if the circular claws do not really form a thread in the form of a helix that is wrapped around a cylinder-shaped nail. Indeed, this component is properly named "Christmas tree rivet” and it is a permanent fastener characterized by circular claws along the length of the nail with an increasing radius starting from the tip of the nail. Clearly, this known type of "nail button” is not removable i.e. it cannot be removed without damaging the button or the garment.

With reference to the nail structure, for the sake of clarity the terms "thread" and "threaded" in the present invention shall refer strictly to a thread such as that of common self-tapping screws, and shall not refer to circular claws.

In some applications, however, it is desirable to have a button that can be disassembled and removed from the garment, for example to prevent it from being damaged during machine washing especially if the button has a cap made of precious material such as rhodium or gold.

In the attempt to address this need, removable or dismountable structures of nail-type buttons such as those shown in Figure 2 have been proposed.

In a first example of buttons of this type (Figure 2a) a screw-like male element is joined to a nut-like female element by means of a common screwdriver. Other examples of buttons of this type are also disclosed in the applications JP2004121576A and US3474504A.

These known removable buttons have two main drawbacks that have limited their application. First, they require the fabric to be pre-punched in the position where the removable button is intended to be fixed. Furthermore, their application requires different machinery and procedures than those normally available in standard clothes workshops. In particular, buttons must be fixed manually or by means of screwdrivers and cannot be fixed by means of a punching machine.

These limitations have made this type of buttons uneconomical in large-scale productions and have limited their use only to luxury garments which can afford the higher assembly cost. A second example of removable button known in the art is illustrated in Figure 2b. Buttons of this kind are, for instance, disclosed in the utility model 202011901979091 "Button with separable head" in the name of RIRI INDUSTRIES Spa. Buttons like these have a structure that allows to separate only the cap from the body. Therefore, they are partially removable buttons as only the head, and not the entire button, can be removed from the garment. In turn, this feature determines a further significant limitation: a relevant environmental impact arises when the garment reaches end-of-life since it is difficult to remove all the parts of the button from the garment.

With reference to the environmental issue, it should be noted that jeans buttons are often subjected to heavy chemical treatments (e.g. galvanic treatments), which have a very high impact on the environment and thus motivate a proper disposal and recycling of buttons.

In recent years, the “green conscious” of consumers has greatly increased and with environmental concerns on top of producers’ agenda, new structures for easy-to-remove buttons are more and more required. Even more, a new "green paradigm” suggests the use of compostable fabrics (e.g. organic cotton) as fertilizer for the garden. From this point of view the button, which is not compostable in itself, represents a critical component of the garment to manage in the waste disposal and recycling cycle.

In conclusion, for the reasons set out above, there is still a need to improve the structure of "nail" buttons which can be easily removed from garments but at the same time can be attached to the garment using the same machines normally used in the clothes workshops to fix traditional i.e. "non-removable" nail buttons.

DISCLOSURE OF INVENTION

Object/scope of the invention

In view of the above, the present invention intends to overcome the existing disadvantages and drawbacks of the prior art by providing a removable button having an improved structure. Accordingly, it is a first object of the present invention to provide a removable button of the "nail" type that can be easily attached and removed from a garment, for example a garment made of jeans fabric. In particular, this purpose includes a removable button which can be applied to a garment manually or by means of the same machines (e.g. a punching machine) used to fix traditional or "non-removable" nail buttons.

A second important object of the present invention is to provide a removable button of the "nail" type which, once applied to a garment, can be temporarily removed and attached again with ease when desired, for example before machine washing to protect valuable decorative caps of the button head.

In addition, a third important object of the present invention is to provide a removable button of the "nail" type which, once applied to a garment, can be definitively removed to reduce the environmental impact when the garment reaches end-of-life and its disposal as a waste is necessary.

Finally, a last object of the present invention is to provide a removable button of the "nail" type which can be produced in a simple and economical way by means of known technologies.

Additional objects and advantages of the invention will be set forth in part in the detailed description which follows and in part will be obvious from the description or may be learned by practice of the invention.

Technical Solution

These and still other purposes, which will appear more clearly in the specification which follows, are achieved by a removable button of the "nail" type and by a method of applying said button to a garment.

The invention is defined in the appended independent claims 1 and 12 while advantageous features are set forth in the appended dependent claims. The aforesaid claims, to which reference should be made, are hereinafter specifically defined and are intended as an integral part of the present description.

In summary, the inventive concept underlying the present invention consists in the combination of a specific structure for the male and female components, and the use of a standard punching machine to attach the button the fabric. By selecting properly materials and geometry of the male and female components, this combination leads to the formation of a stable thread in the female element which is produced by the male element when the button is fixed to the garment thanks to plastic adaptation mechanisms. In this way, the removable button according to the present invention can be removed and fixed again to the garment any time the user wants, with the aid of a common screwdriver, till the garment reaches ends-of-life.

The practical implementation of the inventive concept has required a long and non-trivial development activity which will be apparent from the following specification.

Brief description of drawings

The present invention will be more fully understood by reference to the following drawings which are provided solely for illustration of the embodiments and not limitation thereof.

Figure 1 show a known type of "nail" button provided with circular claws and not with an authentic threading;

Figure 2 illustrates known type of "nail" buttons, where (a) is a removable button that can be fixed to the garment only by a screwdriver, while (b) is a button that can only be partially disassembled and not completely removed;

Figure 3 illustrates a view along a longitudinal section of the button according to the preferred embodiment of the invention, where (a) shows the female element, while (b) is the exploded view of said female element showing (on the right) the conformation of the 'imprint of the plastic body;

Figure 4 is a longitudinal section of a button according to the preferred embodiment of the invention, before being attached to the fabric (in the middle), with the threaded male component (bottom) separated from the female component (top) before the internal thread is self-formed (for ease of visualization the threaded male component is not shown in section);

Figure 5 is a longitudinal section of a button according to the preferred embodiment of the invention. In detail, (a) shows said button applied to a fabric interposed between the threaded male component and the female component, after the internal thread is self-formed when the button is attached to the fabric. Evidence of the reliefs generated on the surface of the closure element as a result of this process is provided in (b); - Figure 6 is a longitudinal section of a button according to the preferred embodiment of the invention, which schematically depicts the operations for removing the button from the fabric by means of a screwdriver (for viewing convenience, the thread of the male element is not shown in section);

Figure 7 illustrates a view along a longitudinal section of the button in a second preferred embodiment of the invention, where (a) is the female element, while (b) shows the exploded view of said female element;

Figure 8 is a longitudinal section of a button according to a second preferred embodiment of the invention.

These figures illustrate and demonstrate various features and embodiments of the present invention but are not to be construed as limiting the invention.

Further characteristics and advantages of the invention will become apparent from the description of two preferred, but not exclusive, embodiments which follow.

DETAILED DESCRIPTION OF THE INVENTION

First preferred embodiment

With reference to the accompanying Figure 3 and Figure 4, the reference number (1) designates as a whole the removable button according to the preferred embodiment of the present invention.

In this preferred embodiment, intended as a mere example of the invention and not a limitation thereof, the button (1) is composed of: a mushroom-shaped female element (10), comprising a head (11) from which a stem (12) protrudes; and a screw-shaped male element (20) comprising a head (21) from which a threaded element (22) having an external thread (221) protrudes.

Optionally, a decorative cap (15) is applied (e.g. by gluing) on the head (11) of the female element (10). The decorative cap (15) can be made of precious or delicate materials that can be accidentally removed or damaged during washing operation of the garment, especially by wash machine.

The button (1) is attached to a garment by interposing a substrate (T), preferably a fabric (T) between the female and male elements (10,20).

With reference to Figure 3, intended solely for illustration of the invention and not a limitation thereof, the stem (12) encloses a cavity (13), bounded at one end by a first opening (131), and by a closure element (132), which are positioned, respectively, on the head part (11) of the female element (10) and on the opposite side thereof. A hole (133) is provided over the closure element (132), preferably placed in the center.

In the cavity (13) a mushroom-shaped plastic body (14) is inserted through said first opening (131). Said plastic body (14) has a base element (141) having a stem (142) protruding thereof with an impression (144) at the end opposite of this base element (141). Inside said stem (142) there is provided a hole (143), directed along the direction of the stem, preferably a blind hole positioned in the center of the impression (144).

In the preferred embodiment of the present invention, herein provided solely for illustration of the invention and not limitation thereof, the female element (10) and the plastic body (14) are both single bodies made by injection molding.

Preferably the head (11), the stem (12), the cavity (13) and the plastic body (14) all have cylindrical or slightly conical symmetry shapes, wherein the cavity (13) and the holes (133,143) are coaxial to the stem (12). The base element (141) and the head (11) preferably have conic-like shapes. Furthermore, the stem (142) of the plastic body has a diameter slightly greater than that of the cavity (13) of the female element, while the base element (141 ) has a smaller diameter than that of the head (11).

However, according to convenience as well as the type of fabric and garment, these elements can have other geometries, for example they can have a prismatic shape. They can be also different in shape, for example the head (11), the stems (12,142) and the base element (141) may be prismatic in shape, while the cavity (13) cylindrical in shape.

Preferably the impression (144) of the plastic body (14) consists of 4 equal reliefs arranged at 90° from each other to form a cross. However, other configurations of the impression (144) are possible as long as they are suitable for obtaining the technical effect described below. Like a common screw, the visible surface of the head (21) of the male element (20) has a recess (211) to allow engagement of a screwdriver to attach and remove the button (1) from the item of clothes as will be explained below. Said recess (211) can have any shape, for example slotted, cross slot (Philips or pozidriv), torx, hexagonal (alien) or other types.

The female and male elements (10,20) can be made with any of the materials used to make traditional "nail" type buttons, such as steel, brass, Zn-AI-Mg alloy, copper, but also plastic materials such as technopolymers, or a combination thereof.

For the purposes of implementing the present invention, the stem (12) has to be much more rigid than the plastic body (14) for a reason that will be explained below. For example, it has proved to be suitable making the stem (12) of brass (with a wall thickness of about 0.3 mm) and the plastic body (14) of a standard techno-polymer available on the market that the expert in the field is in able to select according to needs.

In the preferred embodiment of the present invention, herein provided solely for illustration of the invention and not limitation thereof, after having inserted the plastic body (14) into the cavity (13) (Figure 4), by means of common tools, it is possible to attach the button (1) to a garment using a common punching machine and the same procedure used to apply traditional non-removable buttons. Said procedure comprises the following steps: first, the head (10) and the nail (20) are axially aligned i.e. they are partially joined; then a fabric (T) is interposed between the two; finally, a pressure is exerted on the head (21) of the male element (20), or equivalently on the head (11) of the female element (10) until the head is completely fixed.

Since the walls of the stem (12) are non-deformable due to the high rigidity compared to that of the plastic body, the threaded element (22) widens the hole (133) of the closure element (132) and the blind hole (143) of the plastic body (14), and thus determines by plastic adaptation self-forming of an internal thread (145) on the inner surface of the enlarged hole (143) which engages the external thread (221) of the threaded element (22). This feature is illustrated schematically in the enclosed Figure 5. The present inventor has verified that the button structure hereinabove described advantageously determines three unexpected technical effects.

Firstly, the structure of the button (1) allows the formation of an internal thread (145) which engages the external thread (221) ensuring an excellent joint between the male and female elements (10,20) as well as with the fabric (T). This effect is achieved on condition that the following selections are properly made: a material for the stem (12) having a much greater rigidity than that of the plastic body (14); a sufficiently sharp profile of the crests of the external thread (221); a suitable pitch of the thread of the threaded element (22) such as to allow the adaptation of the plastic body (14) within the cavity (13); dimensions of the stem (142) of the plastic body (14) slightly higher than those of the cavity (13), to allow complete filling of the cavity (13) with the plastic body (14) and the formation of a stable internal thread (145). Since the thread thus created is stable, it is possible to engage the recess (211) of the head (21) with a common screwdriver in order to: first, totally disassemble the button (1) in a simple way for temporary removal form the garment; and then attach again the button to the garment by using the screwdriver. These results have been experimentally demonstrated by subjecting various buttons according to the invention to static load tests where a mass of 40 kg was applied separately to each of the buttons attached to a jeans fabric: no detachments of buttons from the fabric were recorded. In addition, the load-bearing capacity was maintained even after the temporary removal of the button.

The second technical effect found by the inventor consists in an easier perforation of the fabric (T), with a limited snagging of the same. This is the unexpected result of properly dimensioning the diameters of the threaded element (22) and the hole (133), as well as the thickness of the walls of the stem (12) of the female element (10) according to the features of the selected materials. The dimensioning is carried out in such a way as to generate a mechanical interference between the threaded element (22) and the hole (133) which causes its edges to bend towards the inside of the cavity (13) and lead to the formation of folds (134) which favor a clean cut of the fibers of the fabric (T) and prevent they are dragged within the holes (133,143). Finally, the last technical effect determined by the button structure (1) according to the present invention is related to the impression (144) obtained on one end of the stem (142), which during the button attaching operation (1) acts as a punch producing reliefs (135) on the surface of the closure element (132). Said reliefs (135), for example symmetrical with respect to the hole (133), increase the seal performance between the fabric (T) and the female/male elements (10,20). In addition, they also prevent both the rotation of the button and the fabric snagging, particularly when the button according to the invention is attached to lightweight fabrics. This is due to the particularly surface morphology of the closure element (132) which retains the textile fibers more effectively as the present inventor has experimentally found.

It will be evident to those skilled in the art that the different technical effects hereinabove described are interrelated and are determined by the optimization of conflicting design parameters which required a considerable and non-trivial experimentation activity. For example, the diameter of the hole (133) must be chosen as small as possible, to avoid the fabric to be dragged into the holes (133,143), an effect that would not only hinder the removal of the button by means of the screwdriver but would produce a snag on the fabric during this operation, especially when the button is fixed to lightweight fabrics. Flowever, an excessively small diameter of the hole (133) would irreparably damage the external thread (221) of the threaded element (22) and would not lead to the generation of the internal thread (145).

From the description provided herein, solely for illustration of the invention and not limitation thereof, it will be apparent to those skilled in the art that the removable button structure according to the present invention has numerous advantages. In particular, during the production step of the garment it is possible to apply said buttons using standard punching machines usually used to fix traditional non-removable "nail" buttons, and without the use of screwing machines. Furthermore, thanks to the stability of the internal thread (145) self- formed in the plastic body (14), it is possible to use a common screwdriver to completely disassemble the button (1) and remove it from the garment either definitively or temporarily, before waste disposal of the garment, or before machine washing, or when the user wants to change the aesthetic of the garment by replacing buttons with different ones (Figure 6), again using the screwdriver.

Advantageously, the temporary removal of the button (1) can be done an arbitrary number of times, as it was experimentally found by the inventor.

Furthermore, unlike known removable "nail" buttons, it is not even necessary to make check notches on the female/male elements (10,20) to mark that the correct number of screwing turns of the threaded element (22) has been reached.

Although in the first embodiment of the present invention the operation of fixing the button (1) is first carried out by means of the standard machines used to apply common non-removable buttons to fabrics, manual or automatic screwdrivers can also be used, as it will be disclosed in the next embodiment.

Second preferred embodiment

The second embodiment of the button according to the present invention, intended as a mere example of the invention and not a limitation thereof, refers to a removable button structure of the "nail" type particularly suitable for being applied to previously perforated fabrics of any type, heavyweight or lightweight fabrics.

As illustrated in the accompanying Figure 7 and Figure 8, this embodiment is a variant of the first one. For this reason the same reference numbers will be used in the description which follows to designate components identical to those of the previous embodiment. Unlike the first embodiment, the removable button structure (1) is now characterized by the fact that the female element (10) does not have the closure element (132) and the hole (133) so that the cavity (13) is bounded at the ends by a first opening (131), placed on the head (11) side of the female element (10), and by a second opening (131') opposed to the first. Since the stem

(12) has preferably a cylindric-like shape, these openings (131 ,131') are identical to each other. Furthermore, in this structure, once the plastic body (14) is introduced into the cavity

(13), the stem (142) protrudes from the opening (131') and exhibits the impression (144), which preferably takes the form of a cross with a through-hole (143) in the center. This alternative button structure has the advantage of being cheaper than the previous one, and in addition it can be applied with a screwdriver on perforated fabrics as well as it can be applied by pressure, as in the previous form.

Further details to implement this embodiment will be apparent to those skilled in the art on the basis of the teachings already disclosed related to the previous embodiment.

CONCLUSIONS

To conclude, it has been found that the invention described hereinabove fully achieves the intended aim and objects. In fact, a removable button of the "nail" type having an improved structure has been disclosed. The structure allows to both attach the button by means of traditional punching machines and at the same time the temporary and complete removal of the button from the garment according to the needs. Particularly, temporary removal is useful before garment washing to preserve delicate decorative elements of the button, whilst the definitive removal reduce the environmental impact of the garment when the button reaches end-of-life. The technical effect produced by the structure of the removable button according to the present invention is related to the stable thread in the female element which is produced by the male element during fixing of the button to the garment (by means of standard punching machines), thanks to plastic adaptation mechanisms and an appropriate choice of materials.

It is understood that the invention is not limited to the exemplary embodiments shown and described herein and although the description and examples provided contain many details, these should not be construed as limiting the scope of the invention but simply as illustrative illustrations of some embodiments of the present invention.

For example, it is preferable that the closure element of the stem of the female element has a central cavity to facilitate insertion of the threaded element, but this cavity may not be present and could be made directly from the tip of this threaded element when assembling the female element. Similarly, it is not necessary a central hole in the plastic body to facilitate the formation of the internal thread by the threaded element. Furthermore, the fabric substrate can be replaced by a substrate made of different materials, both made of fibrous and non-fibrous materials, used in the clothing industry and not, such as leather, imitation leather, neoprene or other plastic materials, but also metal and wood. Hence, any modification of the present invention which falls within the scope and scope of the following claims is considered to be part of the present invention.

In conclusion, it appears evident to those skilled in the art that the button structure described here, and developed through a non-trivial inventive effort, represents a significant advancement and allows to obtain a greater usefulness compared to the removable buttons of known type. Where the characteristics and techniques mentioned in any claim are followed by reference signs, these reference marks have been applied solely for the purpose of increasing the intelligibility of the claims and consequently these reference marks have no limiting effect on the interpretation of each element identified by way of example from these reference signs.