"SAFETY INSOLE" DESCRIPTION

The subject of the present invention is a safety insole . ^Safety insole' , in the context of the present invention, is intended to mean an insole having mechanical, chemical and physical characteristics which prevent its perforation by sharp objects which can cause serious injury to a user. More particularly, ^safety insole' must be understood to mean an insole which cannot be crossed by nails of 4.5 mm diameter or above, thrust perpendicularly at a speed of about 10 mm per minute against the said insole with a force which reaches 1100 Newton. These values coincide substantially with those required by the prevailing legislation on the prevention of accidents .

The safety insoles of the known art consist essentially of a suitably profiled metal plate. This plate is inserted into the soles of individual protection footwear in such a way as to be interposed between the ground and the sole of the foot of a user who wears the footwear. More particularly, safety insoles of the known art are positioned in a small interstice formed in the sole of

the shoe, which is usually made of plastic, to be subsequently retained in operating position by means of the introduction of filling material into the interstice in the sole. In this way, even if the user accidentally leans his foot on a nail or a comparable object, the nail penetrates the sole of the shoe and is arrested by the metal insole, which prevents the nail from reaching the sole of the user's foot, thus preserving him from a serious injury.

The Applicant has discovered that the safety insoles of the known art are capable of improvement in various respects . In the first place, the safety insoles of the known art have an excessive thickness due to the metal insert inside the footwear. Consequently, the entire footwear ends up being too heavy and inconvenient during walking. Furthermore, the insoles of the known art offer a degree of protection to the user which is not always satisfactory.

In fact, it can happen that a sharp body such as a nail penetrates the sole of the shoe and reaches the user' s foot without encountering the resistance of the insole. This occurrence, which inevitably causes the

user a disabling injury, is due to the fact that the metal insole is not able to stop nails which penetrate the sole laterally with an inclination (with respect to the precise plane of the sole) such as not to intercept the metal insole but to be able to reach the user's foot anyway.

In fact, because the metal insole has to be inserted into the sole of the shoe, the imprint (that is to say the projection on plan) of the metal insole is necessarily always smaller than the imprint of the sole, in order to guarantee that during walking the insole does not protrude from the sole. In other words, there is always a space between the rear extremity of the shoe and the rear extremity of the metal insole, between the front extremity of the shoe and the front extremity of the metal insole, and between the lateral extremities of the shoe and the lateral extremities of the metal insole. When a nail makes its way into these spaces, it does not encounter any resistance and it reaches the user's foot.

It should also be borne in mind that, as has been said, it is necessary to insert the metal insole into a suitable interstice and jam it there until a filling material has been inserted into the space. Jamming the insole in the operating position is often difficult

and not always crowned with success, given the narrow space available for manipulating and retaining the insole inside the interstice for the time necessary for inserting the filling material. In this context, the principal technical task of the present invention is to propose a safety insole capable of overcoming the disadvantages mentioned above . In particular, it is an object of the present invention to make available a safety insole which is particularly thin and therefore light and comfortable. It is equally an object of the present invention to make available a safety insole capable of blocking sharp bodies irrespective of the direction in which they perforate the sole of the individual protection shoe .

Finally, it is an object of the present invention to propose a safety insole which is easy and quick to fit in individual protection footwear. The declared technical task and the specified objects are substantially achieved by a safety insole including the technical characteristics described in one or more of the attached claims. Further characteristics and advantages of the present invention will become clearer from the indicative, and

therefore non-limiting, description of a preferred but not exclusive embodiment of a safety insole, as illustrated in the attached drawings, in which:

- figure 1 is a perspective representation in section of a safety insole in accordance with the present invention fitted in an article of individual protection footwear; and

- figure 2 is a section along the plane II-II of the insole shown in figure 1. With reference to the attached figures, no. 1 comprehensively denotes a safety insole in accordance with the present invention.

It must be clarified that the term ^safety insole' must, in the context of the present invention, be understood to mean an insole capable of resisting sharp objects without being traversed. In particular, the term ^λ safety' must be understood to denote an insole which, if penetrated by a point of diameter 4.5 mm with a point truncated by 1 mm, thrust perpendicularly to the insole with a force of 1100 N at a speed of 10 m/s, succeeds in restraining this point so that it does not protrude by more than 3 mm from the opposite side. This condition must be maintained even after treatment with acids or alkalis in accordance with the

provisions of ISO EN 20345.

The insole 1 includes a base surface 2 and a top surface 3 opposed to the base surface 2. The sole 1 consists of a multi-layer fabric 4 and is passable from the base surface 2 to the top surface 3 and vice versa by needles of diameter below 20 tenths of a millimetre, of between 4 and 15 tenths of a millimetre, preferably of between 8 and 12 tenths of a millimetre, advantageously of 10 tenths of a millimetre, thrust perpendicularly to the insole 1 with a load of at least 90 N, preferably of between 90 and 400 N, even more preferably of between 150 and 300 N such as for example 200 N, in order to be sewn directly to an upper 101 of an article of footwear 100, preferably by the Strobel technique.

In this way, advantageously, the insole 1 is capable of intercepting any nail which works its way, for example by being trodden on, into the sole 102 of the article of footwear 100, before the nail can reach the sole of a user's foot, irrespective of the angle at which the nail penetrates into the sole. Furthermore, the fact of being able to sew the safety insole directly onto the upper of an article of footwear allows the dramatic lowering of the costs of producing individual protection footwear, because it

is not necessary to resort to complicated positioning of the insole inside the sole.

As was mentioned, the fact that the insole 1 which is the subject of the present invention is passable by needles of the type described above, allows the insole to be sewn to the upper by the Strobel technique. This characteristic enables the costs of producing individual protection footwear to be further reduced, because it is not necessary to resort to special sewing techniques but is sufficient to use sewing techniques and sewing machines (Strobel) well established and rooted in the footwear sector. Also, the insole 1 can advantageously be cut and profiled directly by the shoemaker through the use of conventional templates, ensuring optimised use of warehouse space. In fact, in this way it is not necessary to provide a warehouse including insoles already profiled according to a plurality of shapes and sizes: instead, insoles can be cut and profiled according to the shapes and dimensions which are strictly necessary.

It must be emphasised that, from the point of view of the protection of a user's foot, the fact that the insole 1 is passable by needles of the type described above is for practical purposes irrelevant. In fact,

since nails usually have a length which is substantially a function of their diameter, nails of a diameter below 20 tenths of a millimetre are unlikely to succeed in reaching the sole of a user's foot, since their length is not sufficient to pass through the thickness of the sole of the footwear. In any case, nails having a diameter below 20 tenths of a millimetre are not considered disabling, since they are not capable of inflicting a significant injury on a user, as however does happen with nails of diameter 4.5 mm and above.

From a structural point of view, as has been said, the insole 1 consists of a multi-layer fabric 4 having at least one first pair 5 of layers of fabric 6 coupled together by means of a resin 7.

Preferably, the multi-layer fabric 4 also includes a second pair 5' of layers of fabric 6' coupled together by means of the resin 7', anchored to the first pair 5 as will be made clearer further on in the present description.

In particular, each fabric 6, 6' comprises a weave of satin type (for example irregular satin) or double- faced type, i.e. having a predetermined scheme of warp and weft threads. ^λ Double-faced weave' should be understood to mean a weave by means of which the upper

face of the fabric obtained is not symmetrical with, or is not a mirror-image of, the lower face of the fabric, A double-faced weave is made, for example, by- setting up two series of weft threads, through which a single series of warp threads passes, according to a predetermined scheme.

Advantageously, double-faced weave allows an increase in the weft density (i.e. the number of weft threads per cm of fabric) of fabric layers 6, 6' , increasing the compactness of fabric layer 6 itself.

The high weft density ensures that a nail of large dimensions, i.e. a nail of dimensions of 4.5mm or larger, is detained in one or more intersections of weft and warp, until the point where the weft and warp threads are broken or displaced. The fact that the weft density is not infinite, as in the limiting case of a metal plate, also means that needles of the specified dimensions can pass through the insole 1 and therefore make it sewable. In the preferred embodiment, fabric layers 6, 6' are made with threads obtained from high-tenacity fibres. The fibres are chosen from the group including polyamide, polyester and polyethylene, preferably of high density between 900 and 1200 nominal dtex, advantageously 1100 nominal dtex. More particularly,

each thread consists of a plurality of continuous torsional filaments, preferably from 100 to 500, advantageously 200, with 40-80, advantageously 60 twists per metre.

5 As is better illustrated in figure 2, each layer of fabric 6, 6' has a first surface 6a, 6a' and a second surface 6b, 6b' opposite the first. In particular, each pair 5, 5' has respective first surfaces 6a, 6a' facing each other and respective second surfaces 6b,

I ₀ 6b' located externally.

Layers 6, 6' of each pair are coupled to each other by spreading the above-mentioned resin 7 by means of a doctor blade on the respective first surfaces 6a, 6a' , the said resin 7 being preferably made of a material

I ₅ chosen from the group including natural latex, ethyl vinyl acetate, polyurethane resins and acrylic resins. The resin can possibly include a filler represented by a hard and abrasive material such as ceramic material in micronised form, as for example silica or

20 silicates.

In this situation, with reference still to figure 2, it should be noted that the second surfaces 6b, 6b' of each layer of fabric 6, 6' are devoid of the above- mentioned resin 7.

2 ₅ Advantageously, the layer of resin 7 between the

layers of fabric 6, 6' of each pair 5, 5' confers greater compactness on the layer of fabric 6, 6' itself, because it binds together the threads facing the surface of the layer of fabric 6 impregnated with the layer of resin 7.

It must also be emphasised that spreading the resin 7 by means of a doctor blade allows optimal penetration of the resin 7 itself into the fibres and consequent bonding in depth. The latter characteristic enables greater flexibility to be achieved for insole 1, ensuring it a long operating life. In fact, when subjecting the insole 1 to a variety of bending cycles, it was noted that the insole 1 is still perfectly intact after being subjected to ten times the number of cycles that lead a metal safety insole to break.

Advantageously, the layer of resin 7 is not applied to the external surface of the multi-layer fabric 4 destined to come into contact with the sole of the user' s foot .

This characteristic enables the insole 1 to be more comfortable, since it is preferable to ensure an adequate rate of absorption and de-absorption of moisture in the insole 1 in proximity to the area destined to come into contact with the user's foot.

As mentioned above, the first and second pair 5, 5' of layers are anchored to each other to form the multilayer fabric 4. Advantageously, the coupling of the two pairs 5, 5' is effected through the interposition of a thermoplastic film 8 between the second surfaces βb, 6b' of respective fabric layers 6, 6' of each pair 5, 5' .

The thermoplastic film 8 preferably consists of a polyurethane, polyolefin or EVA film. A suitable method for making the safety insole 1 which is the subject of the present invention requires interweaving weft and warp threads of a material chosen from the group including polyester and polyamide, according to a predetermined double-faced weave, to obtain a first and a second pair 5, 5' of fabrics 6, 6' .

Subsequently, a layer of resin 7 is spread by means of a doctor blade on the first facing surfaces 6a, 6a' of the fabric layers 6, 6' of each pair 5, 5' . This spreading requires extending the liquid resin uniformly over the fabric layer through the use of a spreading blade which distributes the resin uniformly. Preferably, the spreading blade remains stationary while the layer of fabric 6, 6' is made to advance by traction underneath it.

When the first surfaces 6a, βa' of each layer of fabric 6, 6' have been uniformly covered with resin 7 , each pair 5., 5' obtained is put through a dryer, for example an oven, to dry the resin and make it integral with the layers of fabric 6, 6' .

Subsequently, the two pairs 5, 5' are united stably with each other by interposing a thermoplastic film 8 between the two second surfaces 6b, 6b' of respective textile layers 6, 6' of each pair 5, 5' . The pairs 5, 5' , with the sheet of thermoplastic material 8 interposed between them, are passed for example through a heated cylinder opposed to a felt mat, resistant to high temperatures, which melt the sheet of thermoplastic material 8 and unite the two pairs 5, 5' of layers to form the multi-layer fabric 4.

The multi-layer fabric 4, having a textile structure derived from satin, can be made of high-tenacity polyester, polyamide or polyether, or in other equivalent fibres with high tenacity. EXAMPLE

Test-piece A: a multi-layer fabric 4 was prepared, having a textile structure derived from satin. The fabric was made of high-tenacity polyester having a weight of 600 g/m ² , 1100 dtx, 22 warp threads/cm, 29

weft threads/cm.

The fabric was thermofixed to increase its dimensional stability.

The test-piece was subjected to a cycle (method: EN ISO 20344:2004 7.2) which included bending the test- piece and subjecting its surface to a flow of 7.5 ml/min ± 2.5 ml/min of water. The test-piece was also subjected to a load of 80 N ± 5 N during bending. This cycle was repeated for 4 hours and at the end the quantity of water retained by the test-piece was measured, expressed in mg of water retained per cm ² of test-piece .

Subsequently the test-piece was placed in an environment with controlled temperature and humidity for 24 hours, and the quantity of water released by the test-piece was measured, compared with the water absorbed. The results are given below.

A point of diameter 4.5 mm with an angle of 30° and truncated at the point by 1 mm, was made to advance at

a speed of 10 ± 3 mm/min perpendicularly to the test- pieces (method: EN 12568 (98) 7.2.2 mod.). Measurements were taken of the force necessary for penetrating the test-pieces, by means of a dynamometer of the type specified in standard ISO EN 20344 6.2.1. The results are given below.

Test 1 Test 2 Test 3 Force [N] Force [N] Force [N]

Test-piece A 1190 1200 1190

The test-piece was subjected to two types of thermal ageing (method: EN 12568 (98) 7.2.2 mod. - 7.1.5.1 mod.) and the perforation test was repeated. The first type of thermal ageing requires the test-piece to be subjected to a temperature of 60 ± 2 ⁰ C for 4 hours. The second type of thermal ageing requires the test- pieces to be subjected to a temperature of -20 ± 2 ⁰ C for 4 hours.

The results are given below.

The test-piece was subjected to three types of chemical ageing (method: EN 12568 (98) 7.2.2 mod. -

7.1.5.1 mod.) and the perforation test was repeated.

\

The first type of chemical ageing requires the test- piece to be subjected to immersion in a sulphuric acid solution at a temperature of 20 ± 2 ⁰ C for 24 hours. The second type of chemical ageing requires the test- piece to be subjected to immersion in a sodium hydroxide solution at a temperature of 20 ± 2 ⁰ C for

10 24 hours. The third type of chemical ageing requires the test-piece to be subjected to immersion in 2,2,4- trimethylpentane at a temperature of 20 + 2 ⁰ C for 24 hours . The results are given below.

I ₅