WO2000070982A1

WO2000070982A1 - Footwear manufacturing method

Info

Publication number: WO2000070982A1
Application number: PCT/AU2000/000484
Authority: WO
Inventors: Michael Anthony Van Niekerk
Original assignee: Blundstone Pty Ltd
Priority date: 1999-05-19
Filing date: 2000-05-19
Publication date: 2000-11-30
Also published as: AUPQ044799A0

Abstract

A method of manufacturing an article of footwear including an insole (3) having an upper face and a lower face, an upper (2) secured to the insole, a penetration-resistant midsole (5), and a sole element moulded to the upper, said method including providing the insole with a retaining member (4) and positioning the penetration-resistant midsole within the retaining member to be held in a retained position with respect to the insole.

Description

FOOTWEAR MANUFACTURING METHOD

The present invention relates to a method of manufacturing an article of footwear, and to an article of footwear made from this method.

In particular, the present invention relates to a method of including a penetration-resistant midsole in an article of footwear.

As used throughout the description of the invention, the expression "penetration-resistant midsole" refers to a midsole which prevents or inhibits the passage of sharp foreign objects through the midsole and to the foot of the wearer of the footwear.

Footwear articles having a penetration-resistant midsole for protection against penetration include the basic components of an upper, an insole and a sole element, with the penetration-resistant midsole positioned to the underside of the insole.

The principle of using a penetration-resistant midsole (such as steel midsole) for protection against penetration by foreign objects through the sole element and up to the foot of the wearer of the footwear is well established for industrial and military applications. An example of one application is in the manufacture of fire fighting boots where exposed nails in the burnt remains of buildings can be a hazard after the surrounding wood has been burnt away.

There are two common methods used to incorporate penetration-resistant midsoles in articles of footwear. The first method involves providing two holes in the penetration-resistant midsole and using two tacks to tack the penetration-resistant midsole to the insole. The toe region of the upper of the footwear is then lasted to the insole and a sole is moulded to the insole to form the article of footwear. This method is disadvantageous in that if a sharp object passing through the sole element pierces the midsole in the region of the hole, there is a risk that the sharp object will push the tack through the hole and thereby cause injury to the foot of the wearer of the article of footwear. For this reason, holes of a size which enable tacks to be inserted therein are not permitted in penetration-resistant midsoles in the Standards prescribed in various countries .

A second known method for incorporating a penetration resistant midsole into an article of footwear involves attachment of the penetration resistant midsole to the underside of the insole with an adhesive. After attachment of the penetration resistant midsole to the insole with adhesive, the toe region of the upper is lasted to the insole and a sole is moulded to the insole incorporating the steel midsole in a central region against the insole. The accurate location of the midsole in the sole element is essential, and firm retention in position during the toe lasting and sole moulding operations is therefore very important. The high temperatures associated with the toe lasting and sole moulding operation are known to cause problems with the adhesive used to attach the midsole to the insole. This can result in movement of the penetration-resistant midsole and incorrect positioning of the midsole in the article of footwear.

Accordingly, it is an object of the present invention to provide a method for inclusion of a penetration-resistant midsole in an article of footwear which avoids the difficulties associated with the known tacking and adhesive attachment methods. According to the present invention there is provided a method of manufacturing an article of footwear including an insole having an upper face and a lower face, an upper secured to the insole, a penetration-resistant midsole, and a sole element moulded to the upper, said method including providing the insole with a retaining member and positioning the penetration-resistant midsole within the retaining member to be held in a retained position with respect to the insole.

By providing the insole with a retaining member which holds the penetration-resistant midsole therein to be held in a retained position with respect to the insole, the difficulties associated with the known methods for accurately attaching the steel midsole to the insole are avoided. Specifically, this method of location of the penetration-resistant midsole with respect to the insole is not affected by the high temperatures associated with the sole moulding step, and does not necessitate the formation of holes in the penetration-resistant midsole to facilitate attachment to the insole by tacks .

Preferably, the penetration-resistant midsole is received within the retaining member to lie at least partly against the lower surface of the insole.

Preferably, the retaining member locates the midsole against the insole sufficiently securely to restrict or prevent movement of the midsole before and during the sole moulding step.

The penetration resistant midsole may be formed from a variety of suitable materials . Preferably, the penetration resistant midsole is formed from a resilient flexible material.

Preferably, the midsole is formed from a metal material such as steel . The midsole may be formed from a sheet of metal or from a metal mesh, providing the mesh openings are sufficiently small to inhibit the passage of sharp foreign objects.

Preferably, the penetration-resistant midsole is of a complementary shape to the insole and has a periphery that is within the vertical confines of the periphery of the insole.

The retaining member may be of any suitable configuration and may be made from any suitable material.

Preferably, the retaining member comprises a web. More preferably the retaining member comprises a flexible web.

Preferably, the web forms a pocket with the insole. This pocket may have an open base ie. may have an open base that is not affixed to the insole (eg. a strap), or may have a closed base (e.g. may have a closed base affixed to the insole) .

According to one preferred embodiment of the invention, the insole is provided with a plurality of retaining members .

Preferably, the insole has a toe region and a heel region to opposite ends of the insole and the insole is provided with a pair of retaining members, one to either end of the insole.

Preferably, the midsole is located within the retaining members by deforming the midsole to reduce the distance between two lateral ends of the midsole, locating the two lateral ends of the midsole adjacent to the retaining members and allowing the midsole to return to its undeformed structure to locate the two lateral ends of the midsole within the retaining members .

Preferably, the method of manufacturing the article of footwear includes the step of securing the retaining members to the insole.

According to one preferred embodiment of the invention, the insole includes toe and heel regions to either end of the insole and the upper includes toe, side and heel sections, and the method of manufacturing the article of footwear includes the steps of:

(a) securing at least a portion of the upper to the insole;

(b) securing the retaining members to the insole;

(c) positioning the penetration-resistant midsole within the retaining members to lie against the lower surface of the insole at least in the toe and heel regions of the insole; and

(d) moulding a sole element to a lower face of the penetration-resistant midsole.

Steps (a) and (b) may be conducted simultaneously by stitching together the retaining members, the insole and the upper at the toe and heel regions of the insole. The toe section of the upper may then be lasted to the insole in a toe lasting machine so as to incorporate the penetration-resistant midsole within a lasted margin at the toe region of the insole prior to step (d) .

Alternatively, step (a) may be conducted following steps (b) and (c) . Specifically, the two retaining members may be secured to the insole, followed by positioning of the penetration-resistant midsole within the retaining members and then lasting of the toe, side and heel sections of the upper to the insole so as to incorporate the penetration-resistant midsole within this lasted margin.

Preferably, the sole element comprises a polymeric midsole and a polymeric outsole.

The midsole and the outsole may be of dual density with, by way of example, the midsole being made from expanded rubber which forms a cushion layer, and an outsole made from high density rubber which forms a relatively tough outer skin. Alternatively, the midsole and the outsole may be of single density.

According to the present invention there is also provided an article of footwear formed by the method described above.

The present invention is described further by way of example with reference to the accompanying drawings in which:

FIGURE 1 is an exploded perspective view of the underside of the article of footwear in a first stage of manufacture in accordance with one preferred embodiment of the present invention;

FIGURE 2 is a perspective view from the underside of the footwear of article illustrated in Figure 1 in a later stage of manufacture;

FIGURE 3 is a perspective view from the underside of the article of footwear illustrated in Figures 1 and 2 during a later stage in the manufacturing method;

FIGURE 4 is a perspective view from the underside of an article of footwear in accordance with a second preferred embodiment of the invention;

FIGURE 5 is a perspective view from the underside of an article of footwear in accordance with a third embodiment of the invention; and

FIGURE 6 is a perspective view of the heel region of the article of footwear illustrated in Figure 5 with the penetration-resistant midsole raised away from the heel section of the insole.

The article of footwear 1 illustrated in Figures 1 to 3 comprises an upper 2, an insole 3, a pair of retaining members in the form of two fabric webs 4, a penetration-resistant midsole in the form a steel midsole 5, and a sole element (not illustrated) .

In a first stage of manufacture the upper 2 and the insole 3 are aligned with the two fabric webs 4 located one to each end of the insole 3, specifically in a toe region 3a and a heel region 3b of the insole. The fabric web 4 at the toe region conforms to the shape of the region and extends to the edge a lasting margin 9 to be formed in a later stage described below. The fabric web 4 at the heel region likewise conforms to the shape of the heel region and extends a sufficient length inwardly of the heel to be able to retain a heel region of the steel midsole 5. The upper 2, insole 3 and fabric webs 4 are secured together by stitching 8 in a Strobel stitching operation.

The two fabric webs form closed pockets with the insole. However, various other forms of retaining members may be used to fulfil the same function as the fabric webs 4. For example, two strips of fabric or plastic material could be positioned at the toe and heel regions of the insole and secured to the insole in the Strobel stitching operation to form open pockets. Alternatively, pairs of hooks depending downwardly from a peripheral region of the insole at the toe and heel ends thereof may be used to form surfaces within which the steel midsole 5 could be located to be held in a retained position with respect to the insole.

As illustrated in Figure 2, the steel midsole 5 is deformed by bending in the directions shown by arrows A to reduce the distance between the two lateral ends of the steel midsole 5. The deformed steel midsole 5 is brought to the lower face of the insole with the two lateral ends of the midsole adjacent to the webs, and the midsole is then allowed to return to its undeformed structure such that the lateral ends of the steel midsole 5 move in the directions indicated by arrows B to locate the two lateral ends of the midsole within the webs 4. Since the steel midsole 2 is formed from a resiliently flexible material, removal of the force deforming the midsole in the direction indicated by arrows A results in the steel midsole "springing" into its undeformed shape.

As is illustrated in the Figures, the steel midsole 5 is of a complimentary shape to the insole 3 and has a periphery that is within the vertical confines of the periphery of the insole 3.

In the preferred embodiment illustrated, when the steel insole 5 is located within the webs 4, it lies against the lower face of the insole. Of course, it is permissible to have a further element or layer of material disposed between the insole and the steel midsole 5, provided that the retaining members locate the steel midsole 5 against the insole 3 sufficiently securely to prevent movement of the steel midsole 5 with respect to the midsole 3 before and during the sole moulding step.

In a next stage of the procedure illustrated in

Figure 3, the toe region of the upper 2 is lasted in a toe lasting machine (not illustrated) . This machine operates to secure a peripheral toe portion 9 of the upper 2 to the lower face of the insole 3. After this toe lasting operation, the steel midsole 5 is incorporated within the lasting margin 9 at the toe. The fabric web 4 at the heel end of the insole 3 continues to retain the steel midsole 5 at the heel. The lasted, Strobel-stitched upper illustrated in Figure 3 is ready for moulding of the sole.

The arrangement illustrated in Figure 3 is positioned on a conventional injection moulding machine (not shown) and the machine injects outsole material into a cavity in the bottom of the mould assembly to form the outsole 13.

The final step of the method comprises injecting polymeric midsole material into the space between the insole 3 and the outsole 13. In this injection moulding stage, polymeric midsole material moulds to the lower surface of the steel midsole 5 and around the peripheral edge of the steel insole 5 to come into contact with a peripheral edge region or margin of the lower face of the insole 3, and/or the lower margin of the upper 2.

According to a second preferred embodiment of the invention, which is illustrated in Figure 4, a different method is used to secure the upper 2 to the insole (not visible) .

In a first stage of manufacture, two fabric webs 4 are secured by any suitable means such as stitching to the toe and heel regions of the insole. Next, the steel midsole 5 is positioned within the fabric webs 4 by the method described above in relation to Figures 1-3.

According to this embodiment, the upper 2 has a peripheral toe portion 9, peripheral portions 10 and a peripheral heel portion 11. The toe portion 9 of the upper 2 is lasted around the insole 3 and the steel midsole 5 in a conventional toe lasting machine (not illustrated) . This lasting operation can be conducted in a single stage (for example if there is no steel cap to be included within the footwear article) or in two stages according to the standard technique known in the art which enables a steel toe cap (not illustrated) to be incorporated within the article of footwear. The side portions 10 of the upper are pulled around the sides of the insole 3 and steel midsole 5 and are lasted to the insole to incorporate the steel midsole 5 within the margin defined by the peripheral side portion 10. The heel portion 11 of the upper is also lasted to the article of footwear in a standard lasting operation.

According to the third preferred embodiment of the invention illustrated in Figures 5 and 6, only one retaining means in the form of a fabric web 4 is provided.

According to this embodiment of the invention, the upper includes the peripheral toe, side and heel portions 9, 10, 11 respectively. A pair of slits 12 are located in the peripheral region of the upper which divides the peripheral heel region 11 from the peripheral side region 10.

According to this embodiment, the upper includes an outer component which forms the outer surface of the upper (which may be formed from leather) and a lining. The lining includes toe and side sections which underlie the toe and side portions of the upper.

According to this embodiment of the invention, - li the upper including both the outer and inner components is mounted onto a last. In a first toe-lasting operation, the toe portion of the upper (including the toe lining and the peripheral toe portion of the outer part of the upper) is pulled around the toe of the last and the lining is lasted (by way of cementing) to the insole 3. In a first side- lasting operation, the sides of the upper (including the lining and the peripheral side portions of the outer part of the upper) are pulled around the sides of the last, and the side lining is secured to the insole by lasting the lining to the insole with cement. Simultaneously with this side lining lasting operation, the heel portion 11 of the upper is lasted using a series of tacks 13 to the heel region of the insole.

Following these first lasting stages, the outer peripheral toe portion of the upper is pulled back from the toe of the insole and the fabric web 4 is secured to the insole by affixing the fabric web 4 to the peripheral toe portion of the lining which overlies a peripheral toe region of the insole. The outer peripheral side portions of the upper are also pulled back slightly to allow insertion of the steel midsole 5 into the fabric web 4 and within a side lasting margin formed by the peripheral side portions of the upper 10 forward of the slits 12. As is illustrated in Figure 5, the heel region of the steel midsole 5 does not lie within the margin defined by the peripheral heel region of the upper. If a steel toe cap (not illustrated) is to be fitted in the toe region of the article of footwear, a peripheral toe portion of the steel midsole 5 will lie within a flange component of the steel toe cap.

Following location the steel toe cap in the toe region of the article of footwear, the outer toe portion of the upper is pulled over the toe and a second toe lasting operation is conducted to secure the outer toe portion of the upper to the insole. Finally, a second lasting operation is conducted to secure the outer side portions of the upper to the insole. The article is footwear is then ready for moulding of a polymeric sole element thereto.

Many modifications may be made to the preferred embodiment of the present invention described above without departing from the spirit and scope of the invention.

For example, one retaining member located in a central region on the lower face of the insole may be used for positioning the penetration-resistant midsole 5 within the retaining member to be held in a retained position with respect to the insole 3. For example, a strip of fabric material may extend across the width of the insole in a central region and the steel midsole slid into this loop to be held in a retained position with respect to the insole 3. Since this form of retaining member is likely to be less reliable than the pair of retaining members in locating the midsole against the insole for sufficiently securely to prevent movement of the midsole before and during the sole moulding step, this method is not preferred.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of manufacturing an article of footwear including an insole having an upper face and a lower face, an upper secured to the insole, a penetration-resistant midsole, and a sole element moulded to the upper, said method including providing the insole with a retaining member and positioning the penetration-resistant midsole within the retaining member to be held in a retained position with respect to the insole.

2. The method as claimed in claim 1, wherein the penetration-resistant midsole is received within the retaining member to lie at least partly against the lower surface of the insole.

3. The method as claimed in claim 2, wherein the retaining member locates the midsole against the insole sufficiently securely to restrict or prevent movement of the midsole before and during the sole moulding step.

4. The method as claimed in claim 3, wherein the penetration resistant midsole is formed from a resilient flexible material .

5. The method as claimed in claim 4, wherein the midsole is formed from a metal material .

6. The method as claimed in any one of claims 1 to 5, wherein the penetration-resistant midsole is of a complementary shape to the insole and has a periphery that is within the vertical confines of the periphery of the insole.

7. The method as claimed in any one of claims 1 to 6, wherein the retaining member comprises a web.

8. The method as claimed in claim 7, wherein the retaining member comprises a flexible web.

9. The method as claimed in claim 8, wherein the web forms a pocket with the insole .

10. The method as claimed in any one of claims 1 to

9 , wherein the insole has a toe region and a heel region to opposite ends of the insole and the insole is provided with a pair of retaining members, one to either end of the insole.

11. The method as claimed in claim 10, wherein the midsole is located within the retaining members by deforming the midsole to reduce the distance between two lateral ends of the midsole, locating the two lateral ends of the midsole adjacent to the retaining members and allowing the midsole to return to its undeformed structure to locate the two lateral ends of the midsole within the retaining members .

12. The method as claimed in any one of claims 10 to 11 , wherein the method of manufacturing the article of footwear includes the step of securing the retaining members to the insole.

13. The method as claimed in any one of claims 10 to 12, wherein the insole includes toe and heel regions to either end of the insole and the upper includes toe, side and heel sections, and the method of manufacturing the article of footwear includes the steps of:

(a) securing at least a portion of the upper to the insole;

(b) securing the retaining members to the insole; (c) positioning the penetration-resistant midsole within the retaining members to lie against the lower surface of the insole at least in the toe and heel regions of the insole; and

14. The method as claimed in claim 13, wherein steps (a) and (b) are conducted simultaneously by stitching together the retaining members, the insole and the upper at the toe and heel regions of the insole .

15. The method as claimed in claim 13 or claim 14, wherein the toe section of the upper is lasted to the insole in a toe lasting machine so as to incorporate the penetration-resistant midsole within a lasted margin at the toe region of the insole prior to step (d) .

16. The method as claimed in claim 12, wherein step (a) is conducted following steps (b) and (c) .

17. The method as claimed in claim 16, wherein the two retaining members are secured to the insole, followed by positioning of the penetration-resistant midsole within the retaining members and then lasting of the toe, side and heel sections of the upper to the insole so as to incorporate the penetration-resistant midsole within this lasted margin.

18. The method as claimed in any one of claims 1 to

17. wherein the sole element comprises a polymeric midsole and a polymeric outsole.

19. An article of footwear formed by the method as claimed in any one of claims 1 to 18.

20. A method of manufacturing an article of footwear substantially as herein described with reference to the accompanying drawings .

21. An article of footwear substantially as herein described with reference to the accompanying drawings .