The invention generally relates to the production of shoes made out of hard synthetic material and is worn for sports, that is, shoes, in particular encompassing a hard, resistant outer shell made out of thermoplastic synthetic material.
In detail, the invention relates to a method for producing a shoe that can be adapted to the foot of a wearer and that is made out of hard, thermoplastic synthetic material and that is worn for sports, wherein a prefabricated shoe is heated at least in sections and is adapted by applying pressure from the outside and by shaping the heated area. The shoe is then cooled down.
The invention further relates to a strip for carrying out the method as well as to a sports shoe or hard shell shoe, respectively, that can be used as a prefabricated shoe in such a method or that was produced according to such a method, respectively.
Synthetic material shoes that are worn for sports, such as ski boots for downhill skiing or cross-country skiing, are typically made out of synthetic material by means of injection molding. A completion of cross-country ski boots by injecting a shoe sole that includes binding parts onto already prefabricated shoe parts is known from FR 2736515 A. Another type of production is described in CH 530 251 A5, wherein two shoe halves are produced in the method known therefrom by deforming synthetic material plates. The two shoe halves are subsequently joined by welding the synthetic material or also by means of adhesion. An individual fit is not provided thereby.
It is also known from DE 42 24 827 A1 to produce an impression of a part of a body, e.g. of a foot, for the production of an individual piece of clothing, e.g. of a shoe, wherein films are placed around the foot or body part in general, the space between the film and the foot is evacuated and a further film is subsequently applied on top, wherein the space between the two films is then evacuated and the second film is adhered to the first film. The cavity defined by the two films can then be filled with plaster, e.g., so as to obtain the desired impression that can be used as a mold, for instance for a shoe.
In the case of the production of shoes made out of thermoplastic synthetic material, in particular by means of injection molding, it is generally common to create a shoe for a certain shoe size. Oftentimes, however, such a commonly formed shoe does not fit the individual feet of wearers, because feet have different widths, for example in the area of the ball of the toes, or also insteps of varied heights and/or because they can encompass other differences. On principle, it is thus possible to produce the shoes in each case in a custom-made fashion according to the respective shape of the foot (see the above-mentioned DE 42 24 827 A1), which, however, is altogether very extensive and expensive.
On the other hand, U.S. Pat. No. 3,848,286 A already proposed a method in the case of which a shoe, concretely a ski boot, is prefabricated out of thermoplastic synthetic material. Such a prefabricated ski boot is then individually adapted to the respective foot of a wearer in that—after putting on the shoe—the shaft of the shoe is closed relative to the leg of the wearer as air-tightly as possible. After this, the interior of the shoe is evacuated by means of lines that extend through the seal closure or that are connected to an opening in the subshell of the shoe. Heat is furthermore applied to the outside of the shoe and the shoe is pressed against the foot of the wearer and is individually adapted thereto by the higher external air-pressure as compared to the interior of the shoe in response to the corresponding heating of the shoe beyond the softening point of the thermoplastic shoe material. Among other things, it is disadvantageous here that the shoe is to be provided with an evacuation opening and that it is furthermore difficult to tightly close the shaft on the leg, in particular when the wearer wears a so-called thermo-sock for thermally insulting the foot in the shoe, so that only a slight low pressure can be generated in the interior of the shoe, whereby the pressure difference between exterior and interior of the shoe is so small that a good adaptation of the shoe to the foot may possibly be prevented.
It is now the object of the invention to provide for a production of an adapted shoe, that is, an individual adaptation of a shoe to a foot of a wearer, in a simple and reliable manner, wherein in particular an evacuation opening in the shoe may no longer be necessary and a relatively high pressure difference between exterior and interior of the shoe can nonetheless be attained for the deformation of the shoe so as to adapt it to a foot. In so doing, it is supposedly possible to use only a single average tool strip in response to the production of the prefabricated shoe, that is, different general strips should be superfluous as far as possible, even in the case of a given shoe size.
The solve the posed object, the method of the afore-specified type according to a first aspect of the invention is characterized in that a correction strip that is made out of hard material and that is taken from the foot is introduced into the prefabricated shoe and that the heated shoe is pressed onto the correction strip by applying pressure.
In response to the use of such a correction strip that is individually adapted to the foot of the respective wearer, provision can be made for a comparatively good seal as well as for the use of a comparatively higher temperature for the hot deformation, so that the desired adaptation of the shoe is made possible in a simple and efficient manner in response to external pressure application.
In the case of ski boots (for downhill skiing as well as for cross-country skiing), the sole area of the boot has a predetermined function with reference to the interaction with binding parts on the ski, so that the sole area should not be deformed any longer as far as possible in response to the adaptation-deformation of the boot. In this respect, it is thus further advantageous according to the instant invention when a material comprising a higher softening temperature, e.g. 170°, is used for the sole area of the boot than is used for the remaining area of the shoe, e.g. a shell and a cuff.
To provide for an accurate individual adaptation to the foot in the case of a correction strip, it is also advantageous when a base correction strip is produced that is provided with holes at the neuralgic spots, with molded elastic parts being inserted into said holes.
So as to be able to transfer corresponding forces from the leg via the shoe in the case of a sports shoe, in particular ski boot, when engaging in a sport, it is advantageous to provide for a fit that is as tight as possible at certain parts of the foot, whereas a rather comfortable fit of the foot in the boot is desired for other sports. In this context is has thus also proven to be advantageous to use a correction strip that is narrower than the measured human foot between the navicular bone (os naviculare) at the inside of the foot or the base bump at the outside of the foot, respectively, on the one hand, and the area of the ball of the large toe or the area of the ball of the small toe, respectively, on the other hand. On the other hand, it is advantageous here when provision is made in the area of the ball of the toes for an excess and/or when a free space is available in the area of the toes. It is also advantageous for the use as ski boot for downhill skiing when the correction strip encompasses an axis under an angle relative to a vertical axis so as to be able to lean forward.
The afore-mentioned base correction strip can in particular also be produced to simplify the method for each shoe size. However, only a few base correction strips can also be produced for each shoe size. Following the creation of the base correction strip, the mentioned individual adaptation is carried out by inserting the molded elastic parts.
It has further proven to be particularly advantageous for the creation of the correction strip when the shape of the correction strip is obtained by scanning the foot of the respective wearer by means of a digitizing camera and by processing the obtained data in a computer.
It has also proven to be advantageous for a simple pressure application or creation of a pressure differential between exterior and interior of the shoe, for a film to be placed over the entire prefabricated shoe and the correction strip and for it to be closed, for the interior of the film to be evacuated and for the shoe to thus be pressed onto the correction strip and for the shoe to be removed after a dwell period for the solidification of the synthetic material.
In a comparable manner, the invention provides for a method for producing a shoe that can be adapted to the foot of a wearer and that is made out of hard, thermoplastic synthetic material, and is worn for sports, wherein a prefabricated shoe located on the foot is heated at least in sections and is adapted by applying pressure from the outside and by shaping the heated area, whereupon the shoe is cooled. According to the invention, this method is characterized in that, similarly as in the case of the afore-mentioned method, a film is placed over the entire prefabricated shoe, said film being closed in the area of the calf, the interior of the film being evacuated and the shoe thus being pressed onto the foot, whereupon the shoe is removed after a dwell time for the solidification of the synthetic material.
For carrying out the method according to the invention, the invention furthermore provides for a strip that is formed as a correction strip that is made out of hard material and that is taken from the foot of the wearer. In the case of this strip, it is particularly advantageous when the distance between the navicular bone (os naviculare) at the inside of the foot or the base bump at the outside of the foot, respectively, and the area of the ball of the large toe or the area of the ball of the small toe, respectively, is narrower than the measured human foot. It is furthermore advantageous when it is provided as base correction strip for a shoe size and when it is provided with holes at the neuralgic spots, with molded elastic parts being capable of being inserted into said holes. It is also advantageous when an excess is available in the area of the ball of the toes and/or when a free space is available in the area of the toes. It is furthermore advantageous for downhill skiing when the correction strip encompasses an axis that is inclined about an angle relative to a vertical axis so as to be able to lean forward.
As mentioned, the invention also provides for a hard shell shoe for the use in the instant method or produced according to the instant method, respectively, wherein provision is made for a subshell and for a cuff made out of synthetic material and for subshell and cuff in detail to be made out of different synthetic material. Such a hard shell shoe is in particular provided for a method or according to a method as mentioned above, respectively, with said hard shell shoe encompassing a subshell and a cuff made out of thermoplastic synthetic material, wherein at least one area of the subshell is made out of synthetic material comprising a higher softening temperature than that of the remaining area of the subshell and of the cuff.
The invention will be defined in more detail below by means of preferred exemplary embodiments, to which it is not to be limited to, however, and with reference to the drawings. In detail:
The inherently known shoe 11 according to
The outline of a human foot 6 in such a shoe 11 is shown in
The production of the subshell 1 is carried out by means of an injection molding process. An injection molding tool consisting of two mold halves 8 or 8′, respectively, (see
A so-called molded strip 9 that encompasses a different contour than the two mold halves 8 and 8′ in certain areas, whereby a cavity is formed that is filled with liquid synthetic material from an injection molding machine 10, is integrated within the tool that consists of the mold halves 8, 8′. The subshell 1 is formed after the liquid synthetic material in the cavity 7 has cooled down.
The cuff 2 is produced in an analogous manner.
This method, in particular the production of the mold halves 8 and 8′ and of the molded strip 9 is extensive when individually adapted shoes are to be created with it.
To provide for an economical production of shoes, as is known from the shoe making for a custom-made shoe, the molded strip 9 is designed to an average shoe size or foot shape, respectively, so as to provide the possibility of being able to use the shoe for as many wearers as possible. In view of the differences in the case of individual foot shapes, provision is made in the inner shoe 3 for deformable pads, so as to ensure a contact to the external shell on the one hand and so as to form a certain crush zone on the other hand, so as to avoid painful pressure marks on the foot. However, this has the disadvantage that relatively soft zones are created, wherein the transfer of force from the foot to the sports equipment is impaired.
Provision is thus made for a shell that is made out of synthetic material and that can be produced on an average tool strip to be adapted to an individual foot. By means of such a retroactive individual, correct fit, the human foot has good contact to the external shell when engaging in sports, wherein forces created when engaging in sports, for example when skiing, are transferred well between foot and sports equipment.
According to
In detail,
The digitizing camera 12 is not used for the production of images, as is the case in the common photography, but it is a system that provides the opportunity to convert the photographed object, in this case the shape of the foot of the wearer, into data points by means of the photographing, wherein an x-, y- and z-coordinate is assigned to each data point and it thus becomes possible to produce the photographed object in a 1:1 illustration in a three-dimensional manner by means of a computer-controlled machine, e.g. a milling device, in a simple manner.
It can be seen from
Provision is thus made according thereto for an adaptation of the shoe 11, so as to overcome these disadvantages and so as to eliminate cavities between correction strip and subshell as well as cuff, so that an exact fit is attained on the basis of a shoe shell that can be produced in a cost-efficient manner by means of retroactive process steps. The exact fit ensures that painful pressure marks are avoided on the one hand and that the transfer of force onto the sports equipment is optimized.
The principle of such a process can be seen from
The method thus described in principle can be carried out, for example, by using a device according to
The autoclave technology that is used for producing fiber-reinforced synthetic material components comprising a three-dimensional surface provides a further production possibility. An advantage of this technology is that particularly simple, inexpensive tools can be used.
In the case of this production method, see
According to
The use of the autoclave technology also has the advantage that, due to the large interior of the autoclave, many shoes 11 can be formed simultaneously, because the required individual “tool” herein is nothing more than a sack made out of a synthetic material film. Contrary thereto, the “tool” in the case of the method according to
According to
The adapted stiff shoe made out of synthetic material is ready after the interior of the autoclave has cooled down.
The particular advantage of this method is that a plurality of shoes can be formed with simple means.
To attain a plastic deformation of the subshell 1, it is advantageous to bring it to a temperature, which is preferably at least 10° C. above the so-called softening temperature of the used synthetic material.
In the case of the shoe illustrated in
In the case of the shoe according to
The dashed line in
In the area of the calf 31 or of the shin 32, respectively, the correction strip 15 encompasses an excess towards the front and the back that runs upwards in a funnel-shaped manner from the bending area 42, as is illustrated in particular in
It can be seen from the view towards the front in
A heel height can be incorporated into the correction strip 15, that is, the heel stands higher than the ball of the foot 18 relative to the ground by a measure x, as can be seen from
The contour 15′ of the correction strip 15 can run parallel to the foot 31 in the area of the instep 33, starting at the bend 42 up to the toe area. However, it is also possible to chose a different contour that is substantially oriented on the interior surface of the available shoe shell.
An advantageous feature of the correction strip 15 is present in the areas 41 that can be seen in
With this measure, the metatarsal area is compressed slightly, which does not cause pain due to the available jointed bone structure, but which creates a very good support effect from the side and also ensures that the heel 30 is held in its place during the engagement in the sport and cannot slip forward.
On the other hand, it is advantageous to provide for an excess in the area of the ball of the toes 38 and 39, so as not to cause pressure marks on the sensitive bones. It will furthermore be advantageous to arrange an excess in the area of the toes 40, so as to prevent frostbites. Due to the fact that the foot receptors are not blocked by the free space, the natural sense of balance is thus also maintained in the entire toe area 40.
Finally, an axis 19 comprising an angle a relative to a vertical axis Z can also be optionally available in the correction strip 15 (see
The correction strip 15 embodied as stand strip is provided with holes 43 at neuralgic spots in
The parts 44 are preferably produced by means of a synthetic material injection molding method, wherein it has become apparent that a certain elasticity is particularly advantageous for the molding process. Accordingly, materials from the group silicon elastomers as well as thermoplastic elastomers in a Shore hardness range D of between 45 and 65 are preferably suitable.
An advantage of this alternative is that one set of base strips is produced for each shoe size and a great many different feet can be imaged by means of a type of construction kit system comprising different synthetic material parts.
The method for producing or adapting the shoe 11 illustrated in
Preferably, a shoe 11 according to
At a suitable location, e.g. in the front cuff area, the film sack 25 is thereby provided with a valve 22 and a hose 23 by means of which low-pressure or vacuum, respectively, can be applied along the arrow P, that is, air can be extracted so as to evacuate the interior of the film sack 25.
As is shown in
The film 25 is removed after a certain dwell time, which is required to cool down the synthetic material to below the softening temperature and the shoe 11 is integrally molded directly to the leg 50 of the wearer.
Number | Date | Country | Kind |
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A 1636/2007 | Oct 2007 | AT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/AT2008/000367 | 10/10/2008 | WO | 00 | 4/12/2010 |