BITTON, Armand (19.b Hasaharon, : Hedera, 38360, IL)
CLAIMS
1. A process for manufacturing footwear, the process comprising: providing plastic material to a mold; molding said plastic material to form a shoe-upper; removing said shoe-upper from said mold; removing a portion of the shoe-upper to provide for a foot entry; and attaching a sole to said shoe-upper to form said footwear.
2. A process as in claim 1 , wherein the step of molding comprises inserting the mold into an oven and heating and rotating the mold.
3. A process as in claim 1 , wherein the step of molding comprises heating the plastic material and injecting air.
4. A process as in claim 1 , wherein the step of molding comprises melting the plastic material prior to providing the plastic material to the mold.
5. A process as in claim 1 , wherein the mold is made of two or more parts and the method further comprises attaching together the two or more parts.
6. A process as in claim 1 , wherein the shape of the plastic material is selected from the group consisting of ampoules, tubes, pellets and granules.
7. A process as in claim 1 , wherein said plastic material is molded assumes the shape of the inner outlines of said mold.
8. A process as in claim 1 , wherein the shoe-upper is further shaped and stylized.
9. A process as in claim 1 , wherein said footwear is water proof.
10. A process as in claim 1 , wherein said footwear is pre-designed to be suitable for orthopaedic insole. |
PROCESS FOR MANUFACTURING FOOTWEAR
FIELD OF THE INVENTION
The present invention relates in general to footwear items and in particular to the manufacturing thereof.
BACKGROUND OF THE INVENTION
References to shoes can be found from the earliest records of man, and the production of shoes is still commonly a time and labor consuming task. A progression through the centuries shows distinct trends in three areas: function, protection and fashion. Shoemaking is a traditional handicraft profession, which has now been largely superseded by industrial manufacture of footwear. Shoemakers may produce a range of footwear items, such items are generally made of leather, wood, rubber, plastic, jute or other plant material. Presently, machine assisted shoe production is common alongside with the customary hand-making. The apparatus upon which the shoe-upper is shaped is referred to as a last.
The last is traditionally made of iron or wood, or currently of plastic. The last is designed to produce a specific heel height, toe shape and type of footwear, e.g., shoes, boots, sandals. Lasts come in asymmetric pair
members, left and right. After the shoe-upper is formed on the last, a sole is joined to the shoe-upper, typically by stitching or gluing.
In US Patent Application No. 20020023306, a system and a method are disclosed for producing shoe lasts in a three dimensional cavity. The adjustable cavity can include a blow molding apparatus. The adjustable cavity can allow an inflatable hollow last to be formed, using a blow-molding process.
SUMMARY OF THE INVENTION
The present invention relates to a process that reduces much of the labor and time heretofore required in the manufacturing of footwear. In accordance with the present invention, an apparatus for molding of a shoe- upper is used that obviates the need for the last.
Accordingly, the present invention provides a process for manufacturing footwear, the process comprising: providing plastic material to a mold; molding the plastic material to form a shoe-upper; removing the shoe- upper from the mold; removing a portion of the shoe-upper to provide for a foot entry; and attaching a sole to the shoe-upper to form the footwear.
In an exemplary embodiment of the present invention, the mold apparatus, in which the shoe-upper is produced, is made of two separable parts.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
A diversity of molding processes is hereby disclosed for manufacturing footwear in accordance with the present invention; for example, blow molding, injection blow molding, rotational molding and extrusion blow molding. In the various molding applications, the applicable plastic raw material may be supplied as pellets, granules, ampoules or tubes; or any combination thereof. Examples of potentially appropriate plastic materials include natural resins (e.g., natural rubber) as well as synthetic resins (e.g., PVC, EVC).
According to one embodiment, an ampoule is introduced into a hollow mold, in the shape of a shoe-upper and subsequently heated for softening in order to allow blowing into the mold. As the ampoule expands via introduction of compressed air into the hollow mold, it inflates and assumes the interior shape of the mold. After a cooling period the mold is opened, and the initially formed upper part of the shoe is ejected. Alternatively, an injection blow molding, in which pellets or granules of plastics material are provided as the input feed, can be used.
In another embodiment of the present invention, plastic material, either a natural resin (e.g., natural rubber) or synthetic resins (e.g., PVC, EVC), is provided in a powder form. A predetermined amount of plastic powder is supplied to a hollow mold. The mold is loaded into an oven, inside which the mold is rotated around a preferred axis or axes. As the mold becomes hotter the resin begins to melt and adhere to the inner walls of the mold. As the resin
melts, it progressively builds up an even coating over the entire internal surface of the mold. After a cooling period the mold is opened and the shoe-upper is removed.
In a further embodiment of the present invention, plastic material, either a natural resin (e.g., natural rubber) or synthetic resins (e.g., PVC, EVC), is first heated until melted. Then, using a technique of extrusion blow molding the molten plastic is fed through a die to emerge as a hollow pipe section, which when reaching a sufficient length (provided sufficient volume of a material to create the footwear), the pipe section is inserted into a hollow mold. Then, compressed air is blown into the pipe section to inflate it to the shape of the mold. After a cooling period, the mold is opened and the upper part of the shoe is ejected from the mold.
Thus, in accordance with the present invention, the fundamental structural features of the shoe-upper are bestowed in a single molding step. Furthermore, the footwear produced is water proof.
In all of the aforementioned embodiments, after removing the cooled and formed plastic material, a portion of the material is removed (e.g. cut) to allow entry of the user's foot, i.e. a shoe-upper is produced. In some embodiments, this material removal step is followed by further shaping and stylizing. Such further operations may include cutting, gluing and or stitching according to a fashion or a style, until the final shoe shape is obtained.
In one embodiment of the present invention, soles are made to correspond to the final shape and design of the shoe-upper, using the
materials, colors and style required. The stylized shoe-upper and the sole are then joined by means known in the art (e.g. gluing, stitching and so on). In one embodiment of the present invention, the mold used is designed so that the insole of the shoe-upper is formed as an orthopedic insole; or the insole is formed to receive an orthopedic insole.
It should be understood that the above description is merely exemplary and that there are various embodiments of the present invention that may be devised, mutatis mutandis, and that the features described in the above-described embodiments, and those not described herein, may be used separately or in any suitable combination; and the invention can be devised in accordance with embodiments not necessarily described above.