IL45937A

IL45937A - Footwear and method of manufacture

Info

Publication number: IL45937A
Application number: IL45937A
Authority: IL
Original assignee: Ro Search Inc
Priority date: 1973-10-29
Filing date: 1974-10-25
Publication date: 1977-01-31
Also published as: BR7409031A; SE415725B; ES431409A1; IL45937A0; AT350436B; JPS5512243B2; FR2248799B1; GB1482277A; FR2248799A1; DE2450538C2; JPS5078451A; ES222538U; ES222538Y; NZ175807A; SE7413554L; DE2450538A1

Description

FOOTWEAR AMD METHOD PF MANUFACTURE The invention refers to the manufacture of r ^)t-wear, such as shoes, boots, etc* with soles comprising elastomeric material molded directly $o the bottom of the upper, usually comprising material such as leather* Such direct molding of elastomeric sole material is carried out in sole molding devices having a mold last and a sole molding cavity formed by a usually divided side rim part and a piston shaped part for the bottom sole surface* It is known to tighten the upper on the mold last by so-called stringlasting in the absence of a structural lasting sole when the outer sole is strong enough to hold in position the lasting margin of the upper bonded by the elastomer sole* Often a welt secured to the upper at the lasting margin level (insole level) is also bonded to the outer sole.

Improvements of such footwear and manufacturing advantages are obtained by the invention described hereafter in connection with the drawings which show in schemdt&ic cross sections in Fig. 1 the sole edge of an upper in relation to a part of the sole molding device befor juxtaposition with the sole mold cavity , while Fig* 2 shows the same sole edge on conclusion of the sole molding.

Fig. 3 shows an execution of the invention in a side view of a finished shoe.

Fig. 4 to Fig. 7 show variations in the execution of the sole edges, in coess sections thereof.

According to the invention, the elastomeric sole 4 is extended at part of its periphery upwardly, as shown at 5 in Fig. 3 to present an apparent sole height at a multiple apparent sole height might vary, i.e. be greater at t™ toe and/or heel area, and lover at the shank area 6.

Correspondingly, more or less of the upper 1 remains visible.

At the upper edge 2 of the sole extension 5 a sealing welt, located correspondingly spaced from the insole level 3, is secured to the material of the upper 1 , usually leather. The welt comprises an outward extension 15 The material of the welt is preferably elastomeric material compatible with the elastomer of the sole 4. The portion 14 is secured to the upper by a stitching 13 or other means such as heat sealing, etc.

In the manufacture of the footwear, the upper with the welt spaced from the lasting margin 10 is mounted on the mold last 9 of a sole device which includes a sole moldin cavity 25. In a loading station of such soling device the upper is lasted b a lasting string 11 secured to the edge of the lastin margin 10, or by fastening the lasting margin 10 after tightening to an insole 19, or any other of the various lasting methods. As shown in Fig. 1, the lasting string 11 is preferably located on the mold last side between the feather edge and the widest part of the last. This results in savings in material and a reduction in the shirring of the lasting margin. Pig. 1 shows the replacement of upper material between the welt 15 and the lasting margin 10 by a strip 24 secured by a stitching 20 to the lower or inside portion 14 of the welt. Different, such as less expensive, material than the visible upper As shown in Fig. 4, the portion 14 of the wei-,ύ might be extended downward to form the lasting margin 10 and to carry the lasting string 11. When less lasting stresses are needed, the pre-welted upper might be held on the mold last 9 by a welt plate 16, as shown in Fig. 6. When full lasting is required, the strip might be extended, as shown at 28 in Fig. 7, to include not only a lasting margin 10, but also a portion carrying the vamp 26.

Elastomeric sheet stock 28, integrally pervious or made pervious by per orations, is preferred because of its lightweight and its strength to take lasting stresses of the upper and provide resiliency and strength to the upper if bonded to even very soft leather of thinner gauge.

After the mounting and lasting of the pre-welted upp< 1 on the mold last 9, the invention provides for the use of a flat welt plate 16 to bring the outward extending welt 15 from the position shown in Fig. 1 into the position of Fig. 2. The welt plate, usually divided lengthwise, is carried by supports 30 in a preselected spacial relation to the mold last 9, so that the correct position of the welt 15 can easily be checked by the operator in the loading station* The absence of a cavity side frame and/or cavity bottom assures ease of flattening the welt, as well as inspection. Thereafter, the unit of mold last, with welt plate and its locating and locking supports 30, is moved into juxtaposition with the sole molding cavity 25· In closing the mold cavity the edge of the welt portion 15 is clamped between the lip plate 16 and edge 32 of the mold cavity so that there is not direct contact between the Frequently, the molding cavity parts are heated while the lip plate 16, spaced from the heated parts by the outer edge of the welt, remains cool* The welt plate, as a result of the insulating effect of the edge of the welt remains cool to the touch, even should the bottom cavity be heated to the high temperature necessary for vulcanization. This allows the operator to handle the welt plate freely during the molding operation thus increasing his efficiency. This feature also permits the use of heat-sensitive upper material, such as vinyl, which would otherwise be burned by contact with the welt plate. The clamping of the outer edge of the welt assures not only the aforementioned spacing, but also a reliable sealing of the mold cavity even if elastomers with a very high flow rate are used, such as blown urethanes. The lip plate 16 is also used to force the material of the upper 1 around groov^ the ds£s sastXB 21 of the mold last 9, such a step as showAn in Pig. 1 , or a groove as shown in Fig. 6· In either case, the deformation of the material of the upper around an edge assures satisfactory sealing of the upper to the last to prevent the running of elastomer upwardly beyond the sealing groove.

After the molding of the sole 4, either by pouring, injection, or other molding, the footwear is removed from the soling device and the previously clamped edge of the welt 15 trimmed to the sole circumference. The trimming after de-molding can be very close to the upper, giving a nearly weltless appearance, without danger of elastomer flowing to the outside of the welt.

Claims

The lastxng margin, which might be part of tl J upper material, or other material connected to it or to the welt, in another execution of the invention, is fastene to a centerless insole, i.e. an insole which extends to the feather edge but is open in its center to allow the inward movement of the lasting margin even after it is secured to the insole. The centerless insole 29, as shown in Fig. 7, is thereafter at least at its inner portion, embedded in the elastomer of the sole* The absence of a center in such centerless insole allows the stitching of the lasting margin, inside or outside of the insole* In either case, the embedding of the inner edge of the insole improves the securing of the sole to the upper* C L A I S :

1. Footwear having an upper of material such as leather and a sole comprising elastomeric material, molded to a prewelted upper, characterized in that said welt is located on said upper spaced upwardly from the insole level of said sole, and the elastomeric sole material at least on part of the sole periphery extending upwardly to said welt and bonded thereto*

2. Footwear having a welt above the insole level, as described in claim 1, characterized in that the material between said welt and said insole level differs from the upper material visible above said welt, preferably said wel connecting said upper material above the welt with the material below said welt.

3. Footwear according to claim 2, characterized' j.n that the material below said welt carries the lasting means such as lasting strings, preferably located above the insole level, and below the widest part of the upper (last).

4. Footwear according to claim 2, characterized in that the lasting means (lasting margin) include elastomeric sheet stock connected to the upper material above the insole level, said elastomeric sheet stock preferably extending upward through at least part of the vamp as a pervious, resilient carrier also for thin and supple leather.

5. Footwear according to claim 1, characterized in that the upward sole extension has a thickness which is a level multiple of the sole thickness below the insole/ said extension preferably being strongly tapered towards the sole bottom.

6. Footwear according to claim 1 , characterized in that said welt comprises elastomeric material compatible with the sole elastomer, said welt preferably extending towards the insole level and carrying the lasting means,

7. Footwear according to claim 1, characterized in that the lasting means, such as a lasting margin on the insole level are secured to a centerless insole which is at least partly embedded in the sole elastomer*

8. The method of manufacture of footwear as described in claims 1 to 7 inclusive, characterized in that the following steps are carried out sequentially! providing an upper of material such as leathe^.-with lasting means and a welt strip preferably located substantially above the insole level mountin and lasting said upper on the last of a sole molding device in the loading (lasting) position of said mold last, without a structural insole; locating a lip frame only against said welt and locking it in the desired position relative to said mold last in absence of the sole mold cavity; moving said upper on said mold last and the sole mold cavity into juxtaposition to clamp the outer rim of said welt between lip plate and cavity rim, and molding a sole comprising elastomer material to said welt and upper while maintaining said lip plate spaced from said sole cavity part by said welt and an air gap, and providing a temperature difference between said lip plate and said sole cavity part, preferably by heating the latter.

9. The method of claim 8, further characterized in that said lasting step carried out by tightening a lasting string located between the widest part and the bottom of said last, while said lasting string is secured to material connected to said upper.

10. · The method of claim 8, further characterized in that said lasting step includes the fastening of a lasting margi to a centerless insole and thereafter embedding and bonding at least the inner edge of said centerless insole in the elastomeric sole materialo

11. The method according to claim 8, wherein said upper is provided with lasting means comprising elastomeric sheet stock, preferably extending through the vamp of the upper as a resilient and at least partially pervious carrier for thin and supple upper material, said elastomer stock being set (molded) to the mold last during the molding of the sole*

12. The method according to claim 8, characterized in that said lip plate secures the sealing of the mold cavity both on the outside of the upper (by clamping the welt between said lip plate and the outside rim of the mold cavity) and on the inside of the upper against the mold last by pressing the edge of said lip plate against the material of the upper to conform it to a of said last. -Aviv, October 24, 1974 AGENT POH APPLICANTS