Description

Field of invention

This invention relates to the footwear sector and, more specifically, the professional footwear sector, and concerns a toe cap provided with a special band designed to make the footwear lighter, much more stable, with minimum elongation and greater resistance to impact than the known safety footwear. Background of the invention

According to the known state of the art, the toe cap is an element fitted inside professional footwear to cover and protect the toes. It ensures a certain amount of resistance of the footwear to impact at the tip and to compression. There are various types of toe caps on the market, differing in materials, thicknesses and weights.

Metal toe caps are characterized by reduced thickness, between 1.8 and 3 mm, and significant weight, between 70 and 85 g. This adds to the final weight of the footwear making it heavier. They also have the drawback of not being flexible: in case of impact, the material undergoes permanent damage and the footwear has to be replaced immediately.

Toe caps in composite material are lighter, with weights between 45 and 60 g, but thicker, up to 7 mm. This affects comfort, on the one hand, as there is less room for the toes, and on the other, the footwear also suffers esthetically: the finished aspect of any size footwear is that of one at a full size larger. The material is very flexible, however, so that after an impact it tends to return to its original shape and this extends the average life of the footwear, which can resist many impacts.

When a toe cap is struck by an impact or pressure, it undergoes the following alterations [Figures la and lb]: 1. the top (a) is creased along the direction of the blow (d);

2. the sides of the toe cap (b, c) forced outward by the power of the blow tend to widen, spreading away from each other along the directions (el, e2);

3. the toe cap tends to upend, rotating backward toward the direction (f).

The consequence of these alterations in shape is the reduction of the free height (h) so that the toes may be crushed, even when the plastic toe cap does not break.

The toe caps described above, whether metallic or non-metallic, have many disadvantages that facilitate alterations 1, 2, and 3.

The flange (g) is too short (< 10 mm) and not sufficiently thick (< 2 mm); this makes it too easy for the sides of the toe cap to spread.

To resolve the problem of alteration on impact, the walls of the toe cap tend to be thickened [Figure lc] in the zone of the tip (p) which is easily encased in the sole, while on the sides (b, c) the tendency is to reduce the thickness so as not to swell the lateral profile of the footwear excessively. Thickening at the tip makes the toe cap larger, and when it is assembled the finished footwear is elongated outward (r) by one or two sizes with respect to the size of the interior shape. The typical thicknesses at the tip of the toe caps on the market are made of molded plastic and measure from 7 mm to 10 mm; this thickness is added to the length of the shape when the toe cap is assembled. Considering that in the development of sizes the difference between one size and the next is 6.5 mm, it becomes clear that the entire footwear is extended lengthwise by one or two sizes.

This adds more weight to the entire footwear and makes walking in them more uncomfortable because the physiology of the foot is not respected; the elongated toe tends to rise, in time, while walking, increasing the risk of tripping. The lower portion immediately above the weight-bearing flange (i, 1) also becomes thinner due to the inclusion of the protective band in soft plastic that rests its initial and final ends precisely on the flange at those points (i, 1). If the angle (φ) of tilt of the tip is too sharp, this facilitates its tipping forward when struck on the back, so that the toes may be crushed by effect of the lower of the edge due to the rotation. In fact, when as the tip is struck on the point (m) the force of the blow tends to push the toe cap along the direction (f).

At the state of the art, in the professional footwear sector the following documents are known:

- US 2007/289165 Al that discloses a toe for safety footwear comprising: a shell shaped in such a way as to receive the extremity of a foot placed in the footwear; a lining which is structurally separated from the shell and shaped in such a way as to match the profile of the shell, the lining being integrally bonded to an outer surface of the shell and at least partially covering the same; a layer of elastomer or viscoelastic material having a thickness of between 0.3 and 2.5 mm placed between the shell and the lining.

- US 5 878 511 A that discloses a toe protection device for safety footwear and, more specifically, a metatarsal protection flange system for safety boots.

The toe disclosed in US 2007/289165 Al does not appear to be a breathable toe cap as well as to have the characteristics to resist the impact according to the technical standards of reference.

The invention disclosed in US 5 878 511 A is not just a device to protect the toes, but a metatarsal protection system for safety boots.

Disclosure of the invention

The purpose of this invention is to obtain a lighter toe cap with respect to those known at the state of the art, lightening the total weight of the footwear. Another purpose of this invention is to obtain a toe cap having the minimum thickness at the tip that will guarantee the minimum increase in length of the footwear. Another purpose of this invention is to obtain a toe cap having the maximum breathability.

Another purpose of this invention is to obtain a much more stable toe cap. Another purpose of this invention is to obtain a toe cap having greater resistance to upending.

A further scope of this invention is to obtain a toe cap equipped with a band fitted on it by means of bonding and without the use of adhesives.

Not the least important purpose of this invention is to obtain a toe cap in which the risk of detachment of the band is very low.

Additional characteristics and advantages of the invention will be seen from the description of a preferred, but not exclusive, embodiment of the toe cap that is the subject of this patent application, illustrated for informative purposes but without limitation in the attached drawings in which:

- Fig. la shows a toe cap known at the state of the art in which:

- (a) indicates the top;

- (b, c) indicate the two sides;

- (dl) indicates the direction in which a blow may alter the shape;

- (el, e2) indicate the direction toward which the sides (b, c) of the toe cap spread following a blow;

- (f) indicates the direction toward which the toe cap tends to tilt;

- (g) indicates a flange;

- (i, 1) indicate the lower parts above the flange (g);

- (m) indicates a point at which the toe cap may receive a blow;

- Fig. lb shows the toe cap known at the state of the art following a blow; - Fig. lc shows how a toe cap at the known state of the art and great thickness affects the length of the entire footwear;

- Fig. 2 shows a toe cap (1) according to this invention in several three- dimensional views, in which:

- (a) indicates the tip; - (b, c) indicate the lateral areas;

- (d) indicates a flange;

- (e) indicates the connecting rib between the flange (d) and the vertical walls;

- (f) indicates the external bottom profile where it rests on the flat surface;

- (g, h) indicate the steps on which a band rests (2);

- (i, j, k, 1, m) indicate the vertical windows opened on the toe cap;

- (n) indicates the top central part of the toe cap;

- Fig. 3a shows a lateral view of a toe cap known at the state of the art in which:

- (o) indicates the direction of impact;

- (p) indicates the direction of tilt of the toe cap;

- (φ) is the acute angle of inclination of the lateral profile;

- Fig. 3b shows a lateral view of a toe cap (1) according to this invention in which:

- (o) indicates the direction of impact;

- (p) indicates the direction of tilt of the toe cap;

- (φ) indicates the angle of inclination > 7° of the lateral profile;

- Fig. 4a shows a toe cap (1) equipped with projections (q, r, s, t) necessary to fit a band (2) on it;

- Fig. 4b shows a three-dimensional view of the toe cap (1) with the band (2) according to this invention.

Detailed description of the invention

According to a preferred - but not limiting - embodiment, this invention concerns a toe cap (1) in plastic material that improves the resistance to impact and guarantees, on the one hand, the minimum increase in length of the footwear and, on the other, the maximum lightness.

In order to improve the safety performance and impact resistance, this toe cap (1) possesses the following characteristics in the thickness and profile: - the vertical wall, at the point of closure of the injection mold, which corresponds with the position of the toes inside, has a thickness of < 7 mm at the tip (a) to ensure the minimum extension in length of the shoe, while throughout the lateral areas (b, c), where the lines of force discharge the maximum stress, the walls are 30% thicker above the outline of the volume containing the toes.

- The floor of the toe cap has a flange (d) that makes it possible to anchor the toe cap to the last during assembly and to discharge onto the sole and then onto the ground the pressure due to the impact and any crushing pressure in case of accident. This flange (d) is shaped in such a way as to increase the area in contact with the sole; the interior portion of said flange (d) has been shaped with a very broad band to increase its width and the thicknesses at the point of fastening to the vertical wall, where the leveraging effect of the stress is greatest (the flange (d) behaves like a shelf, discharging the maximum force into the connecting rib (e) of the flange (d) to the vertical walls).

- The external bottom profile resting on the flat surface (f) is usually coupled to facilitate the passage of the plastic material in completion of the sole at the tip (as shown in Fig. lc, q); in this invention the external junction profile of the flange (d) has been shaped with an angle of 90° to increase its capacity to discharge the pressure toward the ground and prevent tilting of the toe cap under stress.

- Also with a view to strengthening the zone of the flange (d), and thus the "stress shelf portion, the protective band (2) is housed on steps (g, h) produced at a height of 10 mm from the upper resting surface of the flange (d) (normally, the toe caps available on the market have the band that starts from the bottom edge of the toe cap border in contact with the flat surface, thus reducing the thickness of the toe cap walls in the zone of greatest stress leveraged on the shelf). - The sturdiness of the assembly consisting of the flange (d) and the connecting rib (e) 10 mm high forms a "horseshoe" that makes the toe cap (1) much stiffer in the area subject to the most stress. When the toe cap (1) is struck in the central upper part (n), the sturdy horseshoe ensures the maximum reduction of deformation due to widening of the toe cap; in fact, having doubled the thickness of the flange (d) and of the walls immediately above it, this acts as a stiffening bar during stress. The base makes the toe cap (1) less crushable and leaves vital space for the toes, reducing possible damage, even when the toe cap does not break.

- To reduce the tilting effect (p) in case of impact, an angle of inclination (φ) of the toe cap (1) > 7° is provided; in this way the direction of impact of the object striking the upper part of the toe cap, even in the part nearest to the edge, falls much more within the projection of the standing base of the flange

(d) , creating a benefit of stability by effect of the rotation movement toward the tip, thus eliminating the risk of contact between the toes and the edge of the toe cap.

- The toe cap (1) has been opened with vertical windows (i, j, k, 1, m) that, on one hand, ensure its lightness and, on the other, its breathability, designed in such a way that they do not interfere with resistance to impact and pressure, and located in areas where the stress forces are minimum. No window is positioned in the zone of the longitudinal midline of the toe cap, and the windows do not open areas of surface near the edge of the tow cap (1), which is one of the zones most subject to stress, and do not invade the area of the rib

(e) and flange (d) in the base. The number of windows may vary depending on the size of the toe cap (1). These windows also serve to lighten the toe cap

(1): two important advantages are thus achieved by this innovation: a lighter toe cap and the maximum breathability of the footwear, also at the tip (a), which is usually hermetically closed in safety footwear (some toe caps on the market have a few simple holes a few mm in diameter for breathability, but the open surface obtained is much smaller than that provided by the windows produced in this invention; moreover, in case of impact, the entire system of holes would be jeopardized).

- To house the toe protection band, normally thermoplastic adhesives are used, but these, which tend to heat up during use of the footwear, lose their adhesive power, which causes the band to separate and fall on the toes where it causes extreme discomfort to the wearer; moreover, the solvents which may be present in the adhesive, and other chemical components in it, may damage the plastic material of the toe cap causing crystallization and making it more fragile in time. In other cases, a band of plastic material, of the same type as the toe cap but softer, is directly applied to the toe cap by direct molding (a second, subsequent injection to the one that produces the plastic toe cap ensures that the two parts adhere directly to one another). The two materials, however, must both belong to the same class of polymer, because otherwise they are not able to combine and molding becomes more complex and costly because more movements are added.

This invention, however, is equipped with projections (q, r, s, t) on the front edge that, with a system of key/lock, ensure the bonding of a protective band (2) that is perfectly adherent and contoured to the toe cap (1), without the use of adhesives. The band (2), produced by independent molding in 3 sizes following the same geometry as the toe cap (1), is simply fitted on it. This prevents the risk of accidental detachment of the band (2) and consequent pressure and pain on the toes. Other significant advantages are: the simplicity of the die used to mold the toe cap (1) and the band (2), which are independent, no labor and time are required to coat them with glue, as they are positioned necessarily by the projections for optimum bonding between the two contact surfaces.

The materials and dimensions of the invention as described above, illustrated in the attached drawings and claimed hereafter, can be of any time depending on the needs. Moreover, all the details can be replaced with others technically equivalent, without for this reason leaving the sphere of protection of this patent application.