Process for producing footwear and apparatus for making the same

Technical field

FIELD OF THE INVENTION The present invention relates to a method of manufacturing a shoe in which the upper is first cut, prepared, sewn into the upper and provided with a front and back toe cap without the tensioning tab, finally, the cup-shaped sole is put on and pressed at least on the toe and heel. The invention further relates to an apparatus for carrying out this method.

BACKGROUND OF THE INVENTION

Today, the manufacture of footwear with cup soles involves approximately seventeen operations. First, the stretch insole is stitched, then the back toe is formed, the hoof is assigned and the tip is stretched. After activation, the sides and finally the heel are stretched. In separate operations, the bottom and sides are roughened and then the bottom and sides are coated with glue. The adhesive must now be activated and the cup sole must be put on. Then the surfaces to be bonded are pressed together and dried. Finally, the shoes are removed from the hooves, the cuts are cleaned, the shoes are completed and the covering insole is inserted.

In the known, just described procedure with a large number of operations, the share of wages in production costs is high. A disadvantage of conventional shoe production is also the relatively high proportion of skin for the stretch tab, for which approximately 30% of the upper skin is consumed. As leather consumption has increased not only in the footwear industry, but also in the automobile construction and in the manufacture of cushion furniture, the best leather is increasingly used, but the production of raw leather has not increased to the same extent. .

In the past, there have been many attempts to make shoes without a tab. For example, DE-OS 23 60 249 relates to a method in which the sole is cut directly onto the outer skin. To this end, the upper is first formed before the sole is sprayed. The upper is then placed on the molding last acting as the upper part of the spray mold, fastened with clips and tightly inserted into the insole formed as the lower part of the spray mold. For anchoring the upper in the sole, an upper edge corresponding to the tensioning edge is required so that the desired skin saving is not achieved. In addition, the production of the sole requires a so-called sprayed hoof, which is not normally split, and therefore cannot be used to stretch the upper to measure. According to this known method, heel-free shoes, so-called kickers, can in any case be produced.

Another attempt to manufacture a footwear without insoles is described in DE-3j 23 42 304. Here, the tip region is formed by suitable cutting of the skin and subsequent sewing. This gives the toe a little apparent shape. In addition, the uppers must be fastened in the tip and heel area of ​​the hoof by means of thorns. However, these spines interfere with the removal of footwear from the hoof, as they may damage at least the lining, but sometimes also the skin. In addition, it limits the special shaping of the modeler's tip in his artistic freedom.

-1GB 278552 B6

According to DE-OS 26 18 183, the upper leather is to be glued to the edge of the upper, pulled up and possibly sewn. However, there is no discussion of how a substantially flat shoe or shoe skin could be fastened to the sole, particularly in the toe area. This process is therefore best suited for making thong sandals.

DE-OS 23 06 129 shows a method and apparatus for preforming a complete shoe upper. At the same time, the rear toe is formed on the two-part adjustable compression mold, but the front toe is merely preformed so that it joins the skin and is ready for the next stretching action.

The manufacture of shoes according to this method also relates to the solution according to DOS No. 2,749,609. The production is based on a relatively thick and firm sole, on the upper side of which a profile corresponding to the foot is formed. Leather straps are fastened to the sides of the sole and are sewn to the upper. The disadvantage of this method is its considerable laboriousness, and the quality of the footwear produced in this way is highly dependent on the care of the operator and requires high-quality leather.

Shoe manufacturing devices are known, for example, from CS AO 183 861, CS AO 143 351 and GB 2 048 648.

A shoe last is known from CS-AO 183 861, consisting of two parts mounted on an articulated pin and attracted by a clamping spring.

CS AO 143 351 describes the creation of a block for an arched part of a shoe in an apparatus for forming the upper of the shoe.

GB 2 048 648 relates to a heel and a top block, respectively, which consists of two parts connected by a pin.

All these devices can be used to shape shoes. However, they are not equipped to tailor the upper.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The object of the present invention is to provide a method of manufacturing a shoe of the above-mentioned type which operates without a tension tab and without tensioning operations, but with the remaining working processes being machine and partly even automatic. the durability does not differ from the existing footwear.

According to the invention, this is achieved by first stitching the toe only after stitching the upper, then the upper is stabilized and axially tightened, while at the same time the rear part is formed and the cup-shaped sole is glued to the upper. The covering insole is preferably inserted after gluing the upper and the sole and can be glued. This saves about 30% of the top skin material and greatly reduces the number of work operations, so that, in addition to the material share, the wage share is drastically reduced in the production costs.

According to a preferred embodiment of the invention, an additional seam may be used to increase the durability of the connection between the sole and the upper. This seam can simultaneously be formed as a decorative seam.

According to a particular embodiment of the invention, after gluing the upper and the bowl sole, the footwear can be steamed at positive pressure, then put on the hoof, dried and removed from the hoof again. Steaming of shoes is recommended especially for leather shoes, which by this final action will get their final shape, corresponding to the last. Since the hooves are only needed in this last processing step, their number can be greatly reduced, thereby obtaining a further rationalization effect. ________ _________________

As already mentioned, the production process according to the invention is largely machine-driven or self-operating. Accordingly, a number of devices, which are used in individual production steps and which interfere with the cost-effective and perfect production of footwear, are also required for carrying out the invention.

The most important and at the same time the most cost-effective device is the machine, which tailor-made the upper, tailored exactly according to the hoof in the peak area. The device comprises a toe and foot mold and a toe and foot molding parts. The essence of the invention is that the toe and heel subforms and the toe and heel press fit parts are displaceably mounted relative to one another. The functional surface of the tip-shaped molding part and the heel-shaped pressing part, respectively, is offset relative to the functional surface of the tip-shaped part and the heel part, respectively, by the height of the roughened adhesive-provided edge of the upper. In this case, an adjustable further tip-shaped molding part and a further shoe-shaped molding part, respectively, are arranged in the height of the roughened, adhesive-provided upper edge of the upper, in addition to the tip-shaped base and the base-shaped base, respectively.

The tip and heel subforms in outline correspond to the hoof and can be fitted with an upper preformed at the tip. The tip thrust member pushes the preformed upper at the tip against the front subform, thereby holding the skin against sliding, but leaving the edge of the upper provided with glue free. By means of the heel thrust piece, the heel region of the upper is pressed, while at the same time the rear toe is extruded and shaped. Here again, the edge of the upper provided with glue remains free. Finally, the other press-fit parts serve to compress the adhesive surfaces after placing the dish-shaped prepared sole on the tensioned and steady upper in order to achieve a perfect glued connection. The toe and heel subforms and / or toe and heel press fit parts can be connected to the heat source.

According to a further embodiment of the invention, the sub-molds by which the upper is tensioned and the pressing molds by which the upper is fixed or compressed are bonded to the pneumatic actuator. Manually performed tasks consist only of putting on the upper, sewing the bowl-shaped sole and removing the glued shoe.

Overview of figures in the drawing

The method according to the invention, as well as the devices necessary for its implementation, will be explained with reference to the drawing, in which Fig. 1 shows an upper as it is cut in a conventional method of making shoes.

-3GB 278552 B6

Giant. 2 shows an upper as it is cut for the method according to the invention.

Giant. 3 shows roughening or ripping of the edge.

Giant. 4 illustrates a tip shape.

Giant. 5 shows the tailored tension of the upper and the deployment of the cup-shaped sole, including the device used.

Giant. 6 shows the prepared and sewn shoes, including the sewing machine used.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a prepared and grafted upper 1 with a tension tab 2 at the lower edge thereof. The area of ​​the tension tab 2 is approximately 30% of the entire upper material.

Giant. 2 shows an upper 2 without a tension tab as used in the production method of the invention.

Giant. 3 shows the roughening of the upper 2ⁱⁿ The outer edge 4 can be roughened to any width, which is in any case adapted to the depth of the insertion into the preformed cup sole.

Giant. 4 shows an upper 2^se roughened edge 4 and preformed toe 5. To form the toe 5, the stitched upper 2 must be subjected to extremely strong tensile deformation, especially if it consists of leather, so as to obtain a shape exactly according to the last, including any reinforcing sticks, removing with hooves. This occurs with the shoe being stretched so far, especially during the tensioning process by pulling on the tension tab

2. Since in the method according to the invention the tensioning edge and thus also the tensioning action are eliminated, the upper 2 must first be shaped almost exactly to the hoof in its tip region before it joins the sole 6. Otherwise it would not be possible to prevent deformation and uneven fold formation.

The preforming of the tip 5 occurs in a separate tip-shaping machine having, for example, an upper mold, a lower mold and a medium mold, the contours of which correspond to the contour of the last. These molds are lined with abrasion-resistant material, which has a certain elasticity and thus allows different skin thicknesses to be equalized.

Giant. 5 shows the most important process step as well as a schematic representation of the apparatus used for this.

The apparatus for carrying out the method comprises a top mold 21, a foot mold 22, a top pressure mold 23 and a foot pressure mold 24. The functional surface of the pressure mold parts 23 and 24 '. disposed relative to the functional surface of the sub-mold 21 and 22 by the height of the roughened, adhesive-provided edge 4 of the upper part 2. In addition to the press fitting 23 and 24, a further press fitting 25 and another heel press fitting 26. having functional surfaces of a thickness at least equal to the height of the roughened, adhesive-provided edge 4. ' The sub-molds 21 and 22, the press-fit parts 23 and 24 and the other press-fit parts 25 and 26 are adjustable with respect to each other by means of a mating drive (not shown) to which they are connected.

A preformed upper 3 is placed on the sub-molds 21 and 22. With the aid of the top pressing mold 23, the upper 3 is stabilized in the tip region on the top sub-mold 21. The two sub-molds 21 and 22 are pneumatically operated. they move apart while the upper is stretched to its final length. The contours of the two molds 21 and 22 correspond to the contours of the finished footwear.

By means of the heel press fitting 24, the upper 3 is pressed in the heel region and stabilized. At the same time, the rear toe is retracted and compressed. To enable the rear toe cap to be activated, the heel mold 22 and the heel mold 24 are connected to a heat source (not shown).

The tip and heel thrust pieces 23 and 24 are formed such that the adhesive-provided edge 4 'remains free on the upper 3. A prepared cup-shaped sole 6 is mounted on this edge 6 '. Further press-fit parts 25 and 26 are now also mechanically or pneumatically moved forward and press the tip region 8 or heel region 9 of the cup-shaped sole 6 onto the molds 21 and 22 and cause such an adhesive connection between the upper 3 and the sole 6.

After shifting the press-fit parts 23 to 26 and relieving tension of the sub-molds 21 and 22, the footwear can be removed from the machine.

Giant. 6 shows a shoe 10 consisting of a cup-shaped sole 6 and an upper 3. To additionally provide a glued connection between the tray. a sewn 28 is sewn by a sewing machine 27 through a sewn sole 6 and an upper 3.

After gluing and eventually stitching, the shoes are steamed in a pressure chamber (not shown), whereby the skin becomes flexible and malleable in a short time. A hoof is now put into the steamed shoes for the first time. The footwear mounted on the hoof is dried with a drying device, the leather getting its final shape. This shape is retained even after removal from the hoof.

The last work consists of finishing and inserting or gluing the covering insole.

The method and apparatus of the invention are industrially applicable in the footwear industry.