Footwear shock absorbing system

• US 5,983,529 A
• Filed: 07/31/1997
• Issued: 11/16/1999
• Est. Priority Date: 07/31/1997
• Status: Expired due to Term

• Current Assignee: Vans Incorporated (V.F. Corporation)
• Original Assignee: Vans Incorporated (V.F. Corporation)
• Inventors: Serna, Ralph
• Primary Examiner(s): PATTERSON, MARIE D
• Application Number:
  US08/904,413
• Time in Patent Office: 838 Days
• Field of Search: 36/28, 36/29, 36/35 R, 36/37, 36/35 B, 36/43, 36/102
• US Class Current: 36/28
• CPC Class Codes: A43B 1/0072 made at least partially of transparent or translucent materials
• CPC Class Codes: A43B 13/10 Metal
• CPC Class Codes: A43B 13/12 Soles with several layers of different materials
• CPC Class Codes: A43B 13/141 with a part of the sole being flexible, e.g. permitting articulation or torsion
• CPC Class Codes: A43B 13/145 Convex portions, e.g. with a bump or projection, e.g. 'Masai' type shoes

Abstract

A shock absorbing cassette for the midsole of an article of footwear is described. The shock absorbing cassette has a cassette base, first and second sets of cushion elements, and a reduced height cushion element in between the first and second sets of cushion elements. The cushion elements are arranged to cushion the heel of the foot. The shock absorbing cassette may be part of a shoe sole shock absorbing system that also includes an insole board having forefoot slits to improve flexing, a thin midsole with a heel pocket for seating the cassette, and a durable outsole.

Claims

1. A shock absorbing cassette for the midsole of an article of footwear, comprising:

a cassette base;

a first set of deformable cushion elements, wherein each cushion element has a wide base and a narrower tip, attached to a front portion of the cassette base;

a second set of deformable cushion elements, wherein each cushion element has a wide base and a narrower tip, attached to a rear portion of the cassette base; and

at least one reduced height cushion element that is shorter than at least one cushion element of either the first or second set of cushion elements, and that has a base that is smaller than the base of any of the first and second sets of cushion elements and has a narrower tip and is attached to the cassette base in between the first and second sets of cushion elements.

2. The shock absorbing cassette of claim 1, wherein the cushion elements are in the shape of truncated cones.

3. The shock absorbing cassette of claim 1, wherein the cushion elements are hemispherically shaped.

4. The shock absorbing cassette of claim 1, wherein the first and second sets of cushion elements are of equal height.

5. The shock absorbing cassette of claim 1, wherein the base of each element of the first set of cushion elements is larger than the base of each element of the second set of cushion elements.

6. The shock absorbing cassette of claim 1, wherein the base of each of the first, second and reduced height cushion elements is attached to the cassette base portion.

7. The shock absorbing cassette of claim 1, wherein the tip of at least one of the cushion elements is attached to the cassette base portion.

8. A method for manufacturing a shock absorbing cassette for an article of footwear, comprising:

forming a cassette base having a front area and a rear area;

forming a first set of cushion elements, wherein each cushion element has a base and a narrower tip;

forming a second set of cushion elements, wherein each cushion element has a base and a narrower tip;

forming a reduced height cushion element that is shorter than at least one cushion element of either the first or second set of cushion elements, the reduced height cushion element having a base that is smaller than the base of any of the first set and second set of cushion elements and having a narrower tip; and

attaching the first set of cushion elements to the front area of the cassette base, the second set of cushion elements to the rear area of the cassette base and the reduced height cushion element to the cassette base in between the first and second sets of cushion elements.

9. The method of claim 8, wherein the cassette base is made of polyurethane.

10. The method of claim 9, wherein the polyurethane is in the range of 57 to 68 durometers.

11. The method of claim 8, wherein the cushion elements are made of polyurethane.

12. The method of claim 11, wherein the density of the polyurethane is in the range of 57 to 68 durometers.

13. A method for manufacturing a shock absorbing system for an article of footwear, comprising:

forming an insole board having a plurality of forefoot slits;

forming a midsole of cushioning material having a thin forefoot section and a heel pocket;

forming a shock absorbing cassette having a cassette base and a first plurality of cushioning elements connected to a front portion of the cassette base, a second plurality of cushion elements connected to a rear portion of the cassette base, and at least one reduced height cushion element connected between, and shorter than at least one of, the first and second plurality of cushion elements, each cushioning element having a base and a narrower tip, wherein the base of the reduced height cushioning element is smaller than the base of any of the first and second sets of cushion elements;

connecting the midsole to the insole board and seating the shock absorbing cassette in the heel pocket; and

attaching a flexible outsole to the midsole and shock absorbing cassette.

14. The method of claim 13, wherein the cassette is formed so that the tips of the cushioning elements face away from the cassette base.

15. The method of claim 13, wherein the cassette is formed so that at least one of the tips of the cushioning elements face the cassette base.

16. The method of claim 13, wherein the midsole cushioning material is CMEVA.

17. The method of claim 13, wherein the heel pocket is shaped to conform to the shape of the shock absorbing cassette.

18. The method of claim 13, wherein the insole board contains heel cuts.

19. A shock absorbing system for a shoe, comprising:

a midsole having a thin forefoot section and a heel pocket;

a shock absorbing cassette comprising a cassette base, a first plurality of cushion elements connected to a front portion of the base, a second plurality of cushion elements connected to a rear portion of the base, and a reduced height cushion element, wherein each cushioning element has a base and a narrower tip, and wherein the reduced height cushion element is shorter than at least one of the first or second plurality of cushion elements, has a base that is smaller than any of the first and second sets of cushion elements, and is connected to a central portion of the cassette base, the cassette seated in the heel pocket; and

a flexible outsole connected to the midsole, wherein the outsole includes a toe area and a heel portion, and includes a curved lateral outside edge.

20. The system of claim 19, further comprising a toe guard attached to the outsole.

21. The system of claim 19, further comprising an insole board connected to the midsole that contains a plurality of heel cuts.

22. The system of claim 19, wherein the lateral outside edge has a curvature in the range of 7.0 to 18.0 degrees.

23. The system of claim 19, wherein the heel portion has a curvature of 25 degrees.

24. The system of claim 19, wherein the toe area has a curvature of 45 degrees.

25. The system of claim 19, further comprising an insole board having forefoot slits connected to the midsole.