Sole construction
View Patent ↗A sole construction for use in the manufacture of a shoe has an outer sole made of a soft and pliable natural or synthetic elastomeric material having a substantially uniform thickness over its entire area. The outer sole has a substantially planar external surface (when relaxed) for contacting the ground, with cuts formed therein to enhance grip. A puncture-resistant inner sheet of woven synthetic fibers is bonded to the internal surface of the outer sole and an inner lining is bonded to the puncture-resistant inner sheet. A removable soft insole may be provided on the inner lining. The sole construction is lightweight and highly flexible such that a foot of a wearer may flex in the same manner as if the wearer was barefoot with the puncture-resistant inner sheet protecting the wearer's foot from accidental injury from sharp objects on which the wearer may tread.
1. A sole construction for a relatively flexible, thin and lightweight shoe comprising:
an outer sole made of a soft and pliable natural or synthetic elastomeric material and having a substantially uniform thickness over its entire area, the outer sole having a substantially planar external surface for ground contact, an opposed inner surface and an up-turned marginal region for the attachment thereto of a shoe upper;
a puncture-resistant inner sheet directly contacting and overlying the inner surface of the outer sole and comprising a woven fabric consisting of or including high strength flexible fibres; and
an inner lining directly contacting and overlying the puncture-resistant inner sheet; wherein the puncture-resistant inner sheet allows the foot to flex naturally of a wearer of a shoe utilizing the sole construction.
2. A sole construction as claimed in claim 1 , wherein the flexible fibres of the inner sheet are tightly woven to render the fabric highly resistant to puncture by a sharp object.
3. A sole construction as claimed in claim 1 , wherein the fibres of the woven fabric are embedded in a flexible resin matrix.
4. A sole construction as claimed in claim 1 , wherein the inner sheet comprises two overlying layers of a woven fabric the overlying layers having similar properties.
5. A sole construction as claimed in claim 1 , wherein the woven fabric comprises or includes synthetic fibres.
6. A sole construction as claimed in claim 5 , wherein the woven fabric consists of or includes fibres of an aromatic polyamide.
7. A sole construction as claimed in claim 1 , wherein the inner sheet is bonded to the inner surface of the outer sole, over substantially the whole of the area of said inner surface.
8. A sole construction as claimed in claim 1 , wherein the substantially uniform outer sole thickness is not greater than 5 mm.
9. A sole construction as claimed in claim 8 , wherein the substantially uniform thickness of the outer sole is not greater than 3 mm.
10. A sole construction as claimed in claim 1 , wherein the hardness of the natural or synthetic elastomeric material of the outer sole is not greater than 65 on the Shore A scale.
11. A sole construction as claimed in claim 10 , wherein the hardness of the natural or synthetic elastomeric material of the outer sole lies in the range of 42 to 54 on the Shore A scale.
12. A sole construction as claimed in claim 1 , wherein the outer sole is made from a polyurethane material.
13. A sole construction as claimed in claim 1 , wherein a pliable insole is provided on the inner surface of the lining.
14. A sole construction as claimed in claim 13 , wherein the insole is in whole or in part of a resilient foam material.
15. A sole construction as claimed in claim 13 , wherein the insole is removable from the lining.
16. A sole construction as claimed in claim 1 , wherein the lining is of a natural or synthetic leather material.
17. A sole construction as claimed in claim 16 , wherein the lining is bonded to the inner surface of the inner sheet.
18. A shoe comprising a sole construction as claimed in claim 1 in combination with a shoe upper attached to the up-turned marginal region of the outer sole.
19. A shoe as claimed in claim 18 , wherein the shoe upper is attached to the marginal region by one or both of stitching and bonding.