WO2000070980A1

WO2000070980A1 - Article of footwear

Info

Publication number: WO2000070980A1
Application number: PCT/AU2000/000483
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: AUPQ044699A0

Abstract

An article of footwear including: (a) an insole (3) having an upper surface, a lower surface and an opening (31); (b) a penetration-resistant midsole (2) which is positioned adjacent to the lower surface of the insole, and which includes a segment below the opening of the insole which defines a cavity region between the penetration-resistant midsole and the plane of the insole; and (c) a sole element (9) moulded from polymeric sole material to the lower surface of the insole (3) so as to incorporate the penetration-resistant midsole (2) as an integral part thereof, said sole element extending through the cavity to the opening in the insole to project to or above the upper surface of the insole to form a load transfer region.

Description

ARTICLE OF FOOTWEAR

The present invention relates to an article of footwear and to a method of manufacturing the footwear.

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

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 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 a 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 firefighting boots where exposed nails in the burnt remains of buildings can be a hazard after the surrounding wood has been burnt away.

Known penetration-resistant midsoles are substantially planar in configuration and are attached directly to a lower of the face of the insole prior to moulding of the sole element to the insole.

Since the penetration-resistant midsole is made from a hard protective material and covers virtually the entire lower surface of the insole, the penetration- resistant midsole restricts the ability of manufacturers of articles of footwear to modify or improve the design of the insole to form footwear articles having improved performance characteristics.

For example, it is not presently possible to manufacture an article of footwear by cutting the insole to form an opening and to extend the polymeric sole element through this opening in the insole to project to or above the upper surface of the insole to form a load transfer region for transferring load between the foot of a wearer of the footwear and the sole element when using a penetration-resistant midsole. It is not permissible to cut the penetration resistant material to form an opening corresponding to that formed in the insole to enable the sole element to extend through the openings in the midsole and insole. Specifically, the provision of an opening in the penetration-resistant midsole defeats the purpose of providing a penetration resistant midsole since foreign objects may project through the sole element, through the cut area of the penetration resistant midsole and to the foot of the wearer of the article of footwear.

Accordingly, it is an object of the present invention to provide an article of footwear having a penetration-resistant midsole which can be combined with other advantageous footwear components .

According to the present invention there is provided an article of footwear including:

(a) an insole having an upper surface, a lower surface and an opening;

(b) a penetration-resistant midsole which is positioned adjacent to the lower surface of the insole, and which includes a segment below the opening of the insole which defines a cavity region between the penetration-resistant midsole and the plane of the insole; and

(c) a sole element moulded from polymeric sole material to the lower surface of the insole so as to incorporate the penetration- resistant midsole as an integral part thereof, said sole element extending through the cavity to the opening in the insole to project to or above the upper surface of the insole to form a load transfer region.

Preferably, the sole element extends through the opening in the insole to project above the upper surface of the insole.

Preferably, the load transfer region is dome- shaped.

Preferably, the opening in the insole and the segment defining the cavity region of the penetration resistant midsole are in the heel section of the footwear.

The opening in the insole may be of any suitable shape and may be in any suitable location. Similarly, the cavity defined by the segment of the penetration resistant midsole may be of any suitable shape and in any suitable location.

The footwear may comprise more than one opening in the insole.

It is possible that the footwear further comprises a member that extends across the or each opening and is secured to the upper surface of the insole. It is preferred that the member be a barrier.

It is preferred particularly that the barrier member be a membrane .

It is preferred more particularly that the membrane be flexible.

It is preferred that the sole element comprises a polymeric midsole component formed from impact energy absorbing material and that the footwear further comprises an outsole secured to the polymeric midsole component .

Alternatively, in a situation where the footwear does not include a polymeric midsole, the sole element may comprise the outsole only.

It is preferred that the impact energy absorbing material be a resilient material.

It is preferred particularly that the impact energy absorbing material be selected from the group comprising rubber (natural or synthetic) such as expanded rubber, polyurethane, PVC and any other suitable polymeric material, or a combination thereof.

It is preferred that the footwear further comprises an upper secured to the insole.

The penetration-resistant midsole may be formed from a variety of suitable materials .

Preferably, the penetration-resistant midsole is formed from a resiliently 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, provided that the mesh openings are sufficiently small to inhibit the passage of sharp foreign objects.

According to the present invention there is also provided a penetration-resistant midsole suitable for inclusion in the article of footwear described above, said penetration-resistant midsole including a substantially planar region for positioning adjacent to the lower surface of the insole, and a segment which extends out of the plane of the planar region to define a cavity.

The cavity region or the segment defining this cavity region of the penetration-resistant midsole may be of any suitable shape and in any suitable location, provided that the penetration resistant midsole includes a continuous surface which will extend across the insole of the article of footwear so as to prevent or inhibit sharp foreign objects from passing from the tread surface of the sole element of the article of footwear to the foot of the wearer of the article of footwear.

Preferably, the cavity defined by the penetration-resistant midsole is located in a heel region of the penetration-resistant midsole.

Preferably, the penetration-resistant midsole includes one cavity.

The penetration-resistant midsole may be made of any suitable material which prevents or inhibits the passage of sharp foreign objects through the midsole.

It is preferred that the penetration-resistant midsole be formed from a resiliently 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, provided that the mesh openings are sufficiently small.

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

Preferably, the segment which defines the cavity is formed by bending the sheet or mesh of resiliently flexible material sufficiently firmly to form a bent cavity region which extends out of the plane of the remaining planar region of the midsole.

According to the present invention there is also provided a method of manufacturing an article of footwear, the footwear comprising an insole, an upper secured to the insole, a penetration-resistant midsole having a substantially planar region for positioning adjacent to the lower surface of the midsole and a segment defining a cavity, and a sole element moulded to the insole to incorporate the midsole, the upper comprising toe, side and heel sections, the method comprising the following steps:

(a) cutting a section of the insole to form an opening;

(b) securing the upper to the insole;

(c) securing the penetration-resistant midsole to a lower surface of the insole so that the cavity of the penetration-resistant midsole is positioned below the opening of the insole; and

(d) moulding the sole element to a lower surface of the midsole to incorporate the penetration-resistant midsole so that the sole element extends through the cavity to the opening to project to or above an upper surface of the insole to form a load transfer region for transferring load between a foot of the wearer of the footwear and the sole element, the sole element comprising a material capable of absorbing impact energy.

Preferably, the penetration-resistant midsole is secured to the insole by 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.

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 prevent movement of the midsole before and during the sole moulding step.

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

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

Preferably, the retaining members comprise webs More preferably, the retaining members comprise flexible webs .

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

Preferably, the retaining means are secured to the insole at the same time as step (b) of 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 a 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 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; and

FIGURE 4 is a cross-section through the heel region of the article of footwear of the preferred embodiment of the invention illustrated in Figures 1 to 3 viewed from the side of the article of footwear.

The article of footwear shown in Figures 1 to 4 comprises an insole 3, an upper 5 having an upper margin 29 that is wrapped over the edge of the insole 3 and secured to a lower surface 11 of the insole 3, a penetration- resistant midsole 2, a polymeric midsole 9 moulded to the lower surface 11 of the insole 3 and to the upper margin 29, and an outsole 13 (which defines a tread of the footwear) moulded to the midsole 9.

The polymeric midsole 9 is formed at least in part from a material that is capable of absorbing impact energy, such as expanded polyurethane or any other suitable resilient material.

The polymeric midsole 9 and the outsole 13 may be of dual density with, by way of example, the polymeric midsole 9 being made from expanded polyurethane of specific gravity of the order of 0.6 gm/cc which forms a cushion layer, and the outsole 13 being made from polyurethane of specific gravity of the order of 1 gm/cc which forms a relatively tough outer skin. Alternatively, the midsole 9 and the outsole 13 may be of single density.

The insole 3 is formed with an opening 15 in the heel section, and the polymeric midsole 9 extends through the opening 15 and projects to the upper surface 7 of the insole 3 to form a load transfer region 31 for transferring load between a heel of the wearer of the footwear and the midsole 9 when the footwear contacts the ground.

The penetration-resistant midsole 2 is in the form of a steel midsole having generally planar toe and heel edge sections 2a and 2b, respectively.

The steel midsole 2 has an upper face which is located against the lower face 11 of the insole 3 in the toe and heel edge regions 2a, 2b. The steel midsole 2 also includes a segment 10 which projects outwardly from a lower face of the steel midsole 2 so as to define a cavity 12 between the upper face of the segment and the plane of the remainder of the steel midsole 2 defined by planar section toe and heel edge regions 2a, 2b.

The cavity region 12 of the steel midsole 2 is formed by pressing folds into the steel midsole 2 in a region which will result in the cavity being positioned below the opening 31 of the insole 3.

The applicant has found that a footwear article having this arrangement of the opening 15 and the midsole 9 which extends through the cavity 12 region between the steel midsole 2 to or above the plane of the upper surface of the insole 3 optimises adsorption of energy at impact and thereby minimises impact shock. This arrangement also provides the benefits associated with a penetration- resistant midsole layer which prevents sharp foreign objects from passing through the sole (in particular the lower density midsole 9) to the foot of the wearer of the article of footwear.

The article of footwear of the present invention may be manufactured by any suitable method.

According to a preferred method of manufacture, in a first stage of manufacture the upper 5 and the insole

3 are aligned with two retaining means in the form of two fabric webs 4 which are located one to each end of the insole 3. More specifically, the two fabric membranes are positioned in a toe region 3a and a heel region 3b of the insole. The upper 5, insole 3 and fabric webs 4 are secured together by stitching 8 in a Strobel stitching operation. The two fabric webs 4 form closed pockets with the insole 3. As illustrated in Figure 2, the steel midsole 2 is deformed by bending in a direction shown by arrows A to reduce the distance between the two lateral ends of the steel midsole 2. The deformed midsole is brought to the lower face of the insole with the two lateral ends of the steel midsole 2 adjacent to the fabric webs 4, and the steel midsole 2 is then allowed to return to its undeformed structure such that the lateral ends of the steel midsole 2 move in the directions indicated by arrows B to locate the two lateral ends of the midsole 2a, 2b within the fabric 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 2 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 2 is located within the fabric webs 4, the toe and heel edge regions 2a, 2b lie against the lower face of the insole 3. 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 steel midsole 2 is located against the insole 3 sufficiently securely to minimise any movement of the steel midsole with respect to the insole 5 before and during the sole moulding step.

In a next stage of the procedure, the toe region of the upper 5 is lasted in a toe lasting machine (not illustrated) . This machine operates to secure a peripheral toe portion 29 of the upper 5 to the lower face of the insole 3. After this toe lasting operation, the steel midsole 5 is incorporated within the lasting margin 29 at the toe. The fabric web 4 at the heel end of the insole 3 continues to retain the steel midsole 2 at the heel. The lasted, Strobel-stitched upper illustrated in Figure 4 is ready for moulding of the sole.

The arrangement illustrated in Figure 4 is positioned on a conventional injection moulding machine

(not shown) and the machine injects outsole material into a cavity in the bottom of a mould assembly to form the outsole 13.

The final step of the method comprises injecting polymeric midsole material into the space between the outsole 13 and the insole 3. More specifically, polymeric midsole material is injected so as to form a polymeric midsole 9 which extends from the upper face of the outsole 13 through to the lower face of the steel midsole 5 and through from the upper face of the segment 10 defining the cavity 12 of the steel midsole 5 up to the plane of the upper face 7 of the insole 3. In the planar region of the steel midsole 2a, 2b, the polymeric midsole material extends to the lower face of the steel midsole 2. A peripheral region of the insole 3 is not covered by the steel midsole 5. Polymeric midsole material extends to this peripheral region of the insole so that the sole element is firmly moulded to the insole 3.

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, the penetration-resistant midsole may be secured to a lower face of the insole by adhesive or mechanical attachment means such as tacks. Nevertheless, it is preferred to provide retaining members as described above. For another example, the polymeric midsole material may extend above the plane defined by the upper face 7 of the insole 3 to provide a raised load transfer region 31.

For another example, the opening in the insole may be formed by cutting the insole to form a flap and thereafter bending the flap downwardly from the plane of the insole so as to be located in the cavity 12. For this and other alternative features concerning the formation of the load transfer region, specific reference is made to international patent application PCT/AU97/00117, which is incorporared herein by reference in its entirety.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An article of footwear including:

(a) an insole having an upper surface, a lower surface and an opening;

2. The article of footwear as claimed in claim 1, wherein the sole element extends through the opening in the insole to project above the upper surface of the insole.

3. The article of footwear as claimed in claim 2, wherein the load transfer region is dome-shaped.

4. The article of footwear as claimed in any one of claims 1 to 3, wherein the opening in the insole and the segment defining the cavity region of the penetration resistant midsole are in the heel section of the footwear.

5. The article of footwear as claimed in any one of claims 1 to 4, wherein the article of footwear further comprises a member that extends across the or each opening and is secured to the upper surface of the insole .

6. The article of footwear as claimed in claim 5, wherein the member is a barrier.

7. The article of footwear as claimed in claim 6, wherein the barrier member is a membrane.

8. The article of footwear as claimed in claim 7, wherein the membrane is flexible.

9. The article of footwear as claimed in any one of claims 1 to 8, wherein the sole element comprises a polymeric midsole component formed from an impact energy absorbing material and the footwear further comprises an outsole secured to the polymeric midsole component .

10. The article of footwear as claimed in claim 9, wherein the impact energy absorbing material is a resilient material .

11. The article of footwear as claimed in claim 10, wherein the impact energy absorbing material is selected from the group comprising rubber (natural or synthetic) such as expanded rubber, polyurethane, PVC or a combination thereof .

12. The article of footwear as claimed in any one of claims 1 to 11, wherein the footwear further comprises an upper secured to the insole.

13. The article of footwear as claimed in any one of claims 1 to 12, where the penetration-resistant midsole is formed from a resiliently flexible material.

14. The article of footwear as claimed in claim 13, wherein the midsole is formed from a metal material .

15. A penetration-resistant midsole suitable for inclusion in the article of footwear as claimed in any one of claims 1 to 14, wherein said penetration-resistant midsole includes a substantially planar region for positioning adjacent to the lower surface of the insole, and a segment which extends out of the plane of the planar region to define a cavity.

16. The penetration resistant midsole as claimed in claim 15, wherein the cavity defined by the penetration- resistant midsole is located in a heel region of the penetration-resistant midsole.

17. The penetration resistant midsole as claimed in claim 16, wherein the penetration-resistant midsole includes one cavity.

18. The penetration resistant midsole as claimed in any one of claims 15 to 17, wherein the penetration- resistant midsole is formed from a resiliently flexible material.

19. The penetration resistant midsole as claimed in claim 18, wherein the midsole is formed from a metal material .

20. The penetration resistant midsole as claimed in any one of claim 18 or claim 19, wherein the penetration- resistant midsole is of a complimentary shape to the insole and has a periphery that is within the vertical confines of the periphery of the insole.

21. The penetration resistant midsole as claimed in any one of claims 18 to 20, wherein the segment which defines the cavity is formed by bending the sheet or mesh of resiliently flexible material sufficiently firmly to form a bent cavity region which extends out of the plane of the remaining planar region of the midsole.

22. A method of manufacturing an article of footwear, the footwear comprising an insole, an upper secured to the insole, a penetration-resistant midsole having a substantially planar region for positioning adjacent to the lower surface of the midsole and a segment defining a cavity, and a sole element moulded to the insole to incorporate the midsole, the upper comprising toe, side and heel sections, the method comprising the following steps:

(a) cutting a section of the insole to form an opening;

(b) securing the upper to the insole;

23. The method as claimed in claim 22, wherein the penetration-resistant midsole is secured to the insole by 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.

24. The method as claimed in claim 23, wherein the penetration-resistant midsole is received within the retaining member to lie at least partly against the lower surface of the insole.

25. The method as claimed in claim 24, wherein the retaining member locates the midsole against the insole sufficiently securely to prevent movement of the midsole before and during the sole moulding step.

26. The method as claimed in any one of claims 23 to 25, wherein the insole is provided with a pair of retaining members .

27. The method as claimed in claim 26, wherein the insole has a toe region and a heel region to opposite ends of the insole and the pair of retaining members are positioned one to either end of the insole.

28. The method as claimed in claim 27, wherein the retaining members comprise webs .

29. The method as claimed in claim 28, wherein the retaining members comprise flexible webs.

30. The method as claimed in any one of claims 27 to 29, wherein the midsole is located within the retaining members by deforming the midsole to reduce the distance between the two lateral ends of the penetration-resistant midsole, locating the two lateral ends of the penetration- resistant midsole adjacent to the retaining members and allowing the penetration-resistant midsole to return to its undeformed structure to locate the two lateral ends of the midsole within the retaining members .

31. The method as claimed in any one of claims 27 to 30, wherein the retaining means are secured to the insole at the same time as step (b) .

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

33. A penetration-resistant midsole substantially as herein described with reference to the accompanying drawings .

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