“X” stitching method for mounting uppers by means of the string-lasting system

Abstract

This is a patent application for an X stitching method, specifically intended for the assembly of uppers by the system known as tied string—stringlaster, with particular application in the footwear segment. The invention includes application to an upper (1), for full assembly of shoes, using string traction (2) as the responsible element for closing the edges of this upper (1), against the mold (3); with the overlock type stitching hereby used as an example of realization.

Claims

1. An X stitching method for mounting uppers using a string lasting system, which includes an application to an upper (1), for full assembly of shoes, using traction string (2) as an element for closing edges of the upper (1), against a mold (3) that has a body and a sole, the method comprising: generating a cross vector tractioning force by sewing, resulting in full, proportional, symmetric and simultaneous fitting, of the upper (1), to the body and the sole of the mold (3), in a region of an insole, completely covering a toe area, an area in a region of a shank and a rear area stitching at least one “X” (X), to an upper (1), for full assembly of shoes, using the traction string (2) for closing the edges of the upper (1), against the mold (3), where a position in which the upper (1) is found in the mold, at the time of the stitching front or back, does not modify the result of stitching; determining a start point (C) and an end point (H) of the stitching; assuring that the traction string (2) has sufficient length to facilitate their fixing ends of the traction string (2) to a tractioner; determining an X position through which the traction string (2) must pass, from one side to another and vice versa; this X position determines an inversion of a stitching side of the upper (1), in the “shank” (C); tractioning the upper (1) in a vector direction (V), resulting in a full fitting of the upper (1), against the mold (3); stitching from the start point (C), until end point (H); and assembling the upper on the mold by tractioning the ends of the traction string (2) after grouping the upper (1) with the mold (3) in accordance with the vector direction (V) resulting in the full closure of the edge of the upper on the mold.

2. The method according to claim 1, wherein stitching the “X” (X) enables assembly of all models of shoes and all known heights of heels; further comprising gluing or injecting the sole to upper.

3. The method according to claim 1, wherein the upper closes on the mold (3) in three-dimensional planes X, Y and Z, in a single operation; resulting in full assembly of a shoe, homogeneously and with sealing.

4. The method according to claim 3, wherein the “X” (X) stitching is performed on a string traction machine (M1), and the tractioning step is performed with a string tractioner module, after the “X” stitching is performed.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention will duly be described in one form of embodiment, and, for better understanding, references will be made to the attached drawings, in which the following are represented:

(2) FIG. 1: shows the overlock type stitch, used here as an example, applied in an “X” to the upper;

(3) FIG. 2: shows the upper with the insole and the “X” stitch next to the mold;

(4) FIG. 3: Top view of the upper with the insole and the “X” stitch, showing the “V” vectorization;

(5) FIG. 4: Side view of the upper with the insole applied to the mold with the string;

(6) FIG. 5: Shows the overlock stitching, used here by way of example, without “X” stitching, in a pattern that does not offer great resistance to traction;

(7) FIG. 6: Shows the assembly by string traction, with the application of stitching only to the external contour of the upper, resulting in unwanted distance and space between the upper and the mold;

(8) FIG. 7: Shows FIG. 6 in side view;

(9) FIG. 8: Shows in perspective the use of metal barbs fixed to the mold;

(10) FIG. 9: Shows, in a side view, the X, Y and Z vectorization;

(11) FIG. 10: Shows, in a top view, the X, Y and Z vectorization;

(12) FIG. 11: Shows a version of the upper and insole with a double “X”, with proportional fitting of the upper, at negative angles of the mold, without the need for metal or fabric latches;

(13) FIG. 12: Shows a model of a pump, with an increased upper in the area of the shank, to allow fitting without a fabric or metal latch;

(14) FIG. 13: Shows a semi-bagged sneaker, i.e., with a fabric latch;

(15) FIG. 14: Shows a string tractioning process in a moccasin with “X” stitching, in a tractioning machine according to the patent application of the same applicant—BR 10 2015 013357 0;

(16) FIG. 15: Shows a string tractioning process in a boot with “X” stitching, in a string tractioning machine in accordance with the patent application of the same applicant—BR 10 2015 013357 0.

DETAILED DESCRIPTION OF THE INVENTION

(17) “X” STITCHING METHOD FOR THE MOUNTING OF UPPERS BY THE STRING-LASTING SYSTEM, the object of this patent application, comprises a methodology with “X” stitching, using an overlock machine or one with a similar function, applied to an upper (1), for the assembly of shoes, in order to provide cross vector traction, resulting in the full, proportional, symmetric and simultaneous fitting of the upper (1), to the body and sole of the mold (3), in the region of the insole, completely covering the three different areas of assembly of shoes, such as the toe, the area in the region of the shank and the rear.

(18) So, the order of the “X” stitching methodology, described herein, can be reversed, or mirrored, or initiated or terminated, at other points of the circuit, depending on the stitching equipment available, or the operator's preference. An alternative example to the overlock stitching, for example, can be the application of the “X” stitching methodology using a programmable automatic sewing machine, CNC, with a Cartesian coordinate table, with or without the third or fourth axle integrated, with a view to increasing the speed of the process, but without discarding other sewing machines, such as zigzag, or even manual sewing.

(19) For the purpose of illustrating the invention, the example of realization hereby used will be the overlock stitching type applied to an upper (1), for the full assembly of shoes, using string traction (2) as the element responsible for closing the edges of this upper (1), against a mold (3), whose shape reproduces the anatomy of the human foot. It is important to clarify that the position in which the upper (1) is found in the mold, at the time of the stitching—front or back—, does not modify the result of the stitching.

(20) The assembly of shoes by string traction (string or stringlaster method) occurs by exerting a traction force on a string (2), sewn on the lower edges of an upper (1), which is compressed, by the traction, against a mold (3), until these edges close. The direction of the movement of the edges, exerted by the string traction (2) is downward and towards the center of the mold.

(21) This tractioning is intended to fully seal the upper (1) and remove any gaps or wrinkles that may prejudice the perfect sealing of the upper, originally on a 2D plane, as it is produced, on and around a three-dimensional mold (3D) (3), which translates the anatomical mold of the human foot.

(22) This “X” stitching and assembly methodology of shoes applies to all models of shoes and all known heights of heels, such as shoes without heels or flat type sneakers, tennis and children's shoes, sandals, men's shoes, safety and occupational shoes, and even pumps and high-heeled women's boots. After this assembly, the sole can be glued or directly injected.

(23) The sequence of the methodology and strategy of the directional sequence of the overlock stitching (hereby used as an example of realization) on the edge of the upper (1), involving the string traction (2), comprises the following steps, with the direction of the stitching being from right to left or left to right: The first procedure is to determine the reference points for the start (C) as shown in FIG. 1, and the end of the stitching (H), in the same FIG. 1. The ends of the string (2) need to be long, to facilitate their fixing to the traction element (tractioner).

(24) It should be clarified that the positions, of the start of the stitching and the location of the “X”, should be determined at the time of the stitching, only in the execution of the models, because on the production line, these positions already come previously marked, usually by small cuts, for the guidance of the seamstress; The second procedure is the demarcation on the upper (1), of the position of the X stitching, which is to say, at this time the right point will be determined where the traction string (2) must pass, from one side to another and vice versa. This point is called the “X” (X) position and is visible in the references (D); (E); (F); and (G), as shown in FIG. 1 and also in the reference (C) of FIG. 2 (region of the shank). This position of the “X” determines the inversion of the side of the overlock stitching in the upper (1), in the region known as the “shank” (C) in FIG. 2. From this point, the upper (1) is tractioned, in the vector direction (V), in accordance with FIG. 1, resulting in the integral fitting of this upper against the surface of the mold, producing maximum efficiency. The traction angle is variable, according to the model of shoe to be assembled (with heels, fiats, women's, men's or children's shoes, etc.). The necessary variation of the traction angle is defined by the different angles, vertical and horizontal, which the model possesses (height of heel, width of shank, etc.). The traction angle, during the traction, provides greater or lesser resistance, at points of the mold; thus the traction is exerted with equal force, but the closure of the upper (1) occurs at slightly different times, for each region of the shoe, previously determined.

(25) Thus, the modeler can decide, based on the combined choice of the position of the “X” and the angle of the string traction (2), which region of the upper needs to be assembled first, so that the fitting of the upper (1) to the mold (3) is complete, proportional, symmetric and simultaneous. As an example, one can cite the assembly of boots, since this model of shoe requires that the region of the instep of the foot, is the first region to be compressed against the mold, so that the fit is perfect and lateral wrinkles do not form during the assembly; Overlock stitching sequence overlapping the traction string: After the demarcations, the stitching at the tip (C) begins, as shown in FIG. 1, observing the progressive sequence until (H) the operation is concluded; Assembly of the upper on the mold and string traction: after the grouping of the upper (1) with the mold (3), the ends of the string are tractioned (2) in accordance with the vertical direction indicated in the references (A) and (B) as shown in FIG. 4 and references (A) and (B) according to FIG. 3; the result is the full closure of the edge of the upper on the mold, with or without insoles, in accordance with the vectorization (V) shown in FIG. 3.

(26) Other characteristics can be credited to the invention, namely: Full assembly of the upper in a single operation: After the overlock stitching is applied to the upper (1), in accordance with the execution of the strategy at “X”, at the points shown in FIG. 1, with the upper (1) pre-attached to the mold and duly heated, the string traction (2) progressively and simultaneously begins, which characterizes the assembly. The resulting traction vectorization on the upper to the mold occurs on three-dimensional planes X, Y and Z, as shown in FIG. 3; FIG. 9 and FIG. 10, in a single operation, this results in the full assembly of the shoe, homogeneously and with perfect sealing; When the upper is mounted, it is exposed to a traction force; this force is distributed throughout its edge simultaneously, generating anatomical stabilization in accordance with the mold, without deformations, free of high voltage lines (great resistance), and sectorized, as occurs in other assembly methods, especially those that use gripping clamps (and traction), by the way the force used is distributed; Coverage of assemblies in different materials that compose the uppers: the “X” stitching strategy allows for the assembly of shoes made with synthetic uppers, but also of leather, or mixtures of leather and synthetic materials, structured with armor and buttressing, previously an exclusive characteristic of partial assembly machines. This is possible because the “X” stitching strategy is associated with the equipment developed by the applicant, whose strength and traction control allow for the assembly of the upper, in any of these materials, in a single operation, in high productivity sequences. This association brings another unexpected advantage to the process, because it eliminates the need to end in a knot, previously necessary to prevent the assembly by “string” from unravelling, after the fitting of the upper. This confers speed on the operation and mobility on the operator; Savings in raw material and reduction in waste: the development of the “string” stitching system based on the strategy of the “X”, led to the consequent assembly of structured shoes of higher added value, consisting of liners, buttresses and armor. Compared to the partial assembly system, which works with the traction clamps, the uppers assembled by string, with the “X” strategy, are reduced, on average by 6 mm along the outer edge; the liner is also reduced by about 8 mm on the edge of the upper, and consequently, the armor (structural reinforcement of the toe) and the buttress (structural reinforcement of the rear) also have their outer edges proportionally reduced. In addition to this, there is no longer a need for lining, armor and buttresses of highly structured thick or rustic materials, for general-purpose shoes, because the traction force, which allows for the full assembly of the upper, does not form tension lines capable of breaking or compromising the upper. The aspect that contributes to the reduction of the residues resulting from the assembly of shoes by string traction, is the general reduction of the area of the upper and its components. This smaller edge will be folded under the upper, to receive the sole, glued or injected, thus concluding the assembly of the shoe. In the partial assembly methods, these edges need to be larger to be fastened by the gripping clamps; however, after being folded and glued to the assembly insole, the edges form a wrinkled crust that needs to be removed, usually by sanding, so that the sole can be properly incorporated into the shoe and the user does not feel discomfort on walking in it. All this extra material, turns into a residue.

(27) Only in the assemblies of leather shoes, by string traction and cross stitching, is the use of sanders necessary and only to make the surface of the edge of the upper that received the adhesive rough and permeable, for the fixing of the sole. In the assemblies by string, with X stitching, it is not necessary to use fabric latches or nails, in the region of the shank, so there are further savings of raw material and a consequent reduction in waste. In the assembly by string, with X stitching, it is possible to assemble the shoe without the assembly insole and without the knot for fixing, which is to say, there is a reduction of the insole material and of labor for the knot of the string, which reductions extended to a large production scale, become highly significant; High quality and a gain in comfort, even in assemblies of models with a high degree of difficulty, using the partial assembly method: Assembly of shoes with high heels, boots and with pointed toes, including with winkle-pickers, of delicate materials, with pre-decorated textures or uppers: The negative angles are challenges for partial assemblies. One of the reasons is the equipment used for this purpose, which is quite crude, executing the bending of the edges of the upper by brute force, causing tension lines, which cause the breakage of the molds, the ruptures of the uppers, the smoothing of textures, making it impossible to assemble an upper with ornaments. The partial assemblies have even more handcrafted characteristics, mainly due to the high dependence on the operators, because the equipment does not have a high degree of automation, thus, each model is positioned and each clamp executes the elongation according to the personal standards of the operator responsible for the assembly of the shoe. This causes a loss in quality, comfort, regularity and time. Although these machines possess resources and technology, they are still used as simple tools and not as machine tools. While the shoes assembled by “string” and with the “X” stitching strategy, have the traction force distributed along the assembly edge of the upper, which prevents the formation of tension lines. The position and the angle of the traction string, in an upper assembly with a X stitching, allows for the full assembly of the upper, with perfect fitting, as predetermined by the modeler at the time of the creation of the model, including the area of the shank, side, rear, toe and instep, without losing productivity, which helps to reduce costs and maintain quality. The gain in comfort is the result of a series of conditions produced by the string traction assembly technique, with X stitching. One of these aspects is the perfect fit of the upper to the mold, capable of copying to the shoe the lines and contours of the human foot, resulting in a shoe with a balanced fit, which respects the anatomy of the foot. Another aspect is the possibility of creating a shoe from more malleable and softer materials, or without an assembly insole, conferring greater flexibility on the shoe. Even the possibility of assembling a pair of shoes, where one foot is equal to the other (repeatability of results) and of respecting the initial predeterminations of the creation of the shoe creation, provided by the modeler, are points to be considered, for gains in comfort; High productivity: Assembly by string traction, with a “X” stitching strategy, allows for the full assembly of the upper in only one operation. Currently, these assemblies take 8 seconds on average, and can go down to 4 seconds, in cases of the assembly of shoes with straight soles, called “flats”. With this system we can fully assemble up to 2200 pairs of shoes with straight soles, in 8 hours of work, or an average of 1800 pairs of shoes of general models. On average, the partial assembly method, assembles 1600 pairs of shoes parts (only the toe, or the toe and the shank, or only the rear, or the rear and the shank), in 8 (eight) hours of work.

(28) FIG. 11 shows a version of an upper (1) and insole (P) with a double “X” (X), with proportional fitting of the upper (1), at negative angles of the mold (3), without the need for metal or fabric latches.

(29) FIG. 12 shows a model of pumps (S), with an enlarged upper (1) in the area of the shank (C), to enable fitting without a metal or fabric latch.

(30) FIG. 13 shows a semi-bagged sneaker (Si), which is to say, with a fabric latch.

(31) FIG. 14 shows the process of string traction (2), in a moccasin (M) with “X” (X) stitching, with said tractioning carried out on a tractioning machine (M1) in accordance with the patent application of the same applicant, where one observes the mold (3) and string traction module (M2), which performs the tractioning operation, once the “X” is realized.

(32) FIG. 15 shows the process of the tractioning of the strings (2) in a boot (B1) with “X” stitching, with said tractioning being realized on a tractioning machine (M1) in accordance with the patent application of the same application, where one observes the mold (3) and the string traction module (M2), which performs the string tractioning operation, once the “X” is realized.