Patent Application
20060230634
The present invention relates to the production of footwear and specifically of plastic footwear, such as clogs, sandals and similar.
In particular, the invention concerns the specific production of footwear in an antistatic plastic material, made by pressure casting and commonly used by health workers in hospitals or closed health structures, where bacterial hygienic control is very important. Despite this particular purpose, such footwear has also a wider public appeal beyond that specific sector, thanks to its comfortable and practical use. Its main characteristic is that it is simply manufactured, in this specific case with a single material, with surfaces easy to clean and accurately disinfect, features that, together with the above-mentioned comfort, make it essential in the clothing of hospital personnel or anyone standing for many hours during the day.
Such a product is perfect in rooms with specific bacterial hygienic needs, such as certain hospital wards and obviously operating theaters. It is certainly easier to clean and sterilize footwear homogeneously manufactured, stamped with no seams and no porous or absorbing materials, or shaped so that it creates few bends or small gaps. Such bends or gaps creating natural receptacles for impurities, that make cleaning and sterilizing operations more complex.
Nowadays, such footwear is almost totally made in a plastic material by pressure casting, except for the strap, which is made separately in a second manufacturing phase, and then soldered to the inner surface of the footwear. When worn, the strap passes around the back above the heel and is closed by a buckle on the external side of the footwear.
Unfortunately, this manufacturing technology alters the above-mentioned characteristics of uniform and simple maintenance when cleaning the product, by overlapping different materials, thereby creating bends and small gaps possible receptacles of germs and bacteria are formed. In addition, the fastener of the buckle on the external part of the footwear is often made of metal, like in the common shoes with similar types of fasteners. Metal fasteners eventually undergo an inevitable oxidation making it unsuitable for certain purposes such as when the elimination of all infecting agents is necessary.
Furthermore, the current manufacturing technology, generally designed for the production of a single body of the footwear, needs a separate manufacturing process for straps and buckles. This involves additional and different working phases, since it is later necessary to apply the buckle to the upper (1a). This process can be carried out either by sewing, with the above-described hygienic consequences, or by soldering, with the further need to find materials compatible with casting. This not only involves a further manufacturing process that generates costs, but it is also still subject, like all the varied components, to possible divisions, cuts, breaks or manufacturing imperfections that make it a critical point of failure in time. As a matter of fact, the buckle cannot be formed of the same material as the footwear, because the soft plastic would not provide a firm clasp of the strap, resulting in its slipping out of place and so releasing the foot. Therefore, the buckle must be made of more rigid plastic that, being different from the plastic used for the footwear, cannot be soldered to the footwear, but must be closed by other means and principally by a metal rivet subject to wear and tear, oxidation and other technical problems.
Regarding the opposite side of the footwear, the one holding the fastener, due to the use of a metal buckle, it is naturally subject to corrosion, which not only endangers the total safety of the footwear, but also requires a separate element fixed to the external side of the footwear or clog, which involves all the problems already described in the fastening of the buckle.
In practice, this drawback is confirmed by the fact that the fastening strap is often ignored or removed, if present, or even eliminated at all by choosing a different kind of footwear without it.
The present invention provides solutions for the above-mentioned and other drawbacks by supplying footwear made by plastic pressure casting, comprising in a single body all the essential elements that allow the fastening of the strap above the heel. In particular, in said footwear, both the strap and the buckle are realized by the same plastic pressure casting employed for the footwear.
The advantages resulting from the present invention comprise the fact that it is possible to eliminate the metal components and realize footwear completely made of plastic; which is easy to wear and easy to clean and sterilize, owing to its manufacturing uniformity; and where the production costs are reduced, avoiding operations of soldering, sewing or rivets, using for the fastening support the same plastic material used for the footwear. In addition, said footwear realized in a single body, involves a minimum risk of failure in critical points, unlike shoes assembled with various supports.
The present invention deals with plastic footwear made by pressure casting.
As shown in
In the internal back portion of the upper (1a), a strap (3) is applied at suitable height for closing around the ankle; said strap having predetermined length according to the various physical needs or sizes. The strap extends from the wearing edge of the upper (1a) and is inserted into a loop (7) of a buckle (4). Said buckle (4) is made in a single body and has a surface (8) comprising one or more buttons (6), for fastening the strap, and a loop (7). The strap (3) comprises sizing holes (3a) which fit over one or more of the buttons (6) of the buckle. Said surface (8) also comprises a buttonhole (5) for the insertion of a button (2) found on the upper 1a of the footwear (1). The button (2) is also formed by the same pressure casting employed to form the footwear.
The surfaces of the footwear are flexible, soft, antistatic and rough stamped making the footwear suitable for its purposes, both in the portion holding the foot, obviously anatomically shaped, and in the fastening strap (3) that is elastic and soft so as not to cause unpleasant sensations when contacting a user's heel.
As shown in
On the contrary, the detail of the buckle fixing the strap to the button is conveniently made of a harder and stiffer plastic material which ensures a longer life and a safer hold, without causing any physical discomfort since this support is not in direct contact with the foot.
Reduced to its essential structure and with reference to the figures of the enclosed drawings, the footwear of the present invention is made of plastic by pressure casting. The footwear according to the invention includes on its upper (1a) a back strap (3), passing above the heel of the footwear, and a button (2). The button (2) extends perpendicularly from a side opposite to the side where the strap attaches to the upper (1a). The button (2) is inserted by pressure into a buttonhole (5) of a buckle (4). The buckle (4) retains the end of the strap. All of these components, namely the button, strap and buckle, are made by the same plastic pressure casting used to form the footwear.
Conveniently, the strap (3) is of a predetermined length and extends from one side of the footwear upper (1a) around the back portion of a wearer's foot. Said strap (3) extends from a first side of the upper (1a) and fastens to buckle (4) by fitting sizing holes (3a) over one or more buttons (6) of the buckle.
As shown in
Said buckle (4) is made in a single body of a stiffer plastic material than the one used for the footwear and has a surface (8) comprising one or more buttons (6) for fastening the strap (3), a loop (7) through which the strap passes before fastening to the buckle and a buttonhole (5) for the insertion of the button (2).
The button (2), formed by pressure casting together with the footwear, can have any shape as long as it enters the buttonhole (5) on the buckle. Said button can either be circular, square, hexagonal or have any other shape providing it is realized in a monolithic single body with the footwear. This button is made of a body and a projecting head. Said head having a greater peripheral dimension than the body, that is elastically deformable and is able to enters the buttonhole (5) extending through the buttonhole. The button (2) then resiles and secures the buckle, with attached strap, to the upper (1a) of the footwear.
The footwear of the present invention also includes a supporting base, of standard thickness, internally shaped providing an anatomical sole, and a top surface or upper (1a) which is thinner and sufficiently soft. From the inner portion of a first side of the upper (1a), the strap extends towards the rear of the foot, while on the outer part of the upper (1a) on the side opposite the side from which the strap (3) extends, there is a button (2) similarly manufactured.
In order to fasten strap and button, a particular buckle made of a different plastic material is used. This plastic material is stiffer and resistant to wear and tear. The buckle is provided with a buttonhole for the simple insertion by pressure of the button (2) of the footwear and also comprises at an opposite end, a loop (7) for the insertion of the strap of the footwear. The strap (3) also comprises sizing holes (3a) that adjust the length of the strap (3) by their relative attachment on buttons (6) of the buckle. Owing to its characteristic of manufacturing in a single body, the present invention involves many economical advantages, avoiding additional processes of soldering or sewing the fastening support. The same manufacturing characteristic guarantees a safer footwear having a longer life, eliminating the failure points that naturally arise where different materials overlap.
The present invention combines the soft wearing portion with the resistant and hard fastening support, the only detail not connected with the manufacturing. Furthermore, owing to the particular type and material of the fastening support, the present invention avoids the use of metal parts at all, while preserving the same functionality, avoiding natural oxidation and corrosion.
As a result of the single material used, together with the manufacturing technology of realizing the invention in a single monolithic body, angles, gaps, “shadow” sectors are eliminated, so as to easily get a complete bacterial cleaning or disinfection of the footwear, which makes it ideal for its specific purpose for use in hospitals and other healthcare facilities as well as for any other use.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI2005U000008 | Apr 2005 | IT | national |
