Method of manufacturing sole assembly for article of footwear

1. A method of forming a midsole comprising the steps of:

placing a first mold member and a second mold member of a first mold assembly in contact with one another;

injecting a first material into a first recess and a second recess in the first mold member to form first and second portions of a midsole preform while the first mold member is maintained at a temperature below an ambient temperature;

positioning the first and second portions in a first midsole recess in a third mold member of a second mold assembly;

placing a second material in the first midsole recess;

placing the third mold member and a fourth mold member of the second mold assembly in contact with one another;

subjecting the second material and the first and second portions in the second mold assembly to heat to form a midsole preform;

placing the midsole preform in a second midsole recess in a fifth mold member of a third mold assembly;

placing the fifth mold member and a sixth mold member of the third mold assembly in contact with one another; and

subjecting the midsole preform in the third mold assembly to heat and pressure to form a midsole.

2. The method of forming a midsole of claim 1 , wherein the first mold member includes at least one additional first recess and at least one additional second recess, an additional first portion of a midsole preform being formed in each additional first recess, and an additional second portion of a midsole preform being formed in each additional second recess.

3. The method of forming a midsole of claim 1 , wherein the first and second portions are positioned in a forefoot portion of the midsole preform, the second portion being positioned rearwardly of first portion.

4. The method of forming a midsole of claim 1 , wherein the first material has a first hardness and the second material has a second hardness that is different than the first hardness.

5. The method of forming a midsole of claim 1 , wherein the second material is placed in the second recess in the form of pellets.

6. The method of forming a midsole of claim 1 , wherein the first mold member of the first mold assembly includes a channel, the channel extending between the first and second recesses and an exterior of the first mold member.

7. The method of forming a midsole of claim 6 , wherein the first material is injected into the first recess through the channel.

8. The method of forming a midsole of claim 1 , wherein the first material is EVA.

9. The method of forming a midsole of claim 1 , wherein the second material is EVA.

10. The method of forming a midsole of claim 1 , wherein the midsole preform is approximately 160-170% of a size of the midsole.

11. The method of forming a midsole of claim 1 , wherein a first groove is formed about a periphery of the first portion of the midsole preform and a second groove is formed about a periphery of the second portion of the midsole preform.

12. The method of forming a midsole of claim 11 , wherein the first groove is formed by a first wall extending upwardly from a bottom of the first mold recess of the second mold assembly, and the second groove is formed by a second wall extending upwardly from a bottom of the first mold recess of the second mold assembly.

13. The method of forming a midsole of claim 1 , wherein a third portion is formed in a heel portion of the midsole preform, a third groove being formed about a periphery of the third portion.

14. The method of forming a midsole of claim 13 , wherein the third groove is formed by a third wall extending upwardly from a bottom of the first mold recess of the second mold assembly.

15. A method of forming a sole assembly comprising the steps of:

placing a first mold member and a second mold member of a first mold assembly in contact with one another;

injecting a first material into a first recess and a second recess in the first mold member to form a first portion and a second portion of a midsole preform while the first mold member is maintained at a temperature below an ambient temperature;

positioning the first portion and the second portion in a first midsole recess in a third mold member of a second mold assembly;

placing a second material having a hardness different than a hardness of the first material in the first midsole recess;

placing the third mold member and a fourth mold member of the second mold assembly in contact with one another;

subjecting the second material and the first and second portions in the second mold assembly to heat to form a midsole preform;

placing the midsole preform in a second midsole recess in a fifth mold member of a third mold assembly;

placing the fifth mold member and a sixth mold member of the third mold assembly in contact with one another;

subjecting the midsole preform in the third mold assembly to heat and pressure to form a midsole;

removing the midsole from the third mold assembly; and

securing an outsole to the midsole.

16. The method of forming a midsole of claim 15 , wherein a first groove is formed about a periphery of the first portion of the midsole preform and a second groove is formed about a periphery of the second portion of the midsole preform.

17. The method of forming a midsole of claim 16 , wherein the first groove is formed by a first wall extending upwardly from a bottom of the first mold recess of the second mold assembly, and the second groove is formed by a second wall extending upwardly from a bottom of the first mold recess of the second mold assembly.

18. The method of forming a midsole of claim 15 , wherein a third portion is formed in a heel portion of the midsole preform, a third groove being formed about a periphery of the third portion.

19. The method of forming a midsole of claim 18 , wherein the third groove is formed by a third wall extending upwardly from a bottom of the first mold recess of the second mold assembly.

20. A method of forming a sole assembly comprising the steps of:

placing a first mold member and a second mold member of a first mold assembly in contact with one another;

injecting a first material into a first recess and a second recess in the first mold member to form a first portion and a second portion of a midsole preform while the first mold member is maintained at a temperature below an ambient temperature;

removing the first and second portions from the first recess and the second recess, respectively;

positioning the first portion and the second portion in a first midsole recess in a third mold member of a second mold assembly;

placing a second material in the first midsole recess in the third mold member;

placing the third mold member and a fourth mold member of the second mold assembly in contact with one another;

subjecting the second material and the first and second portions in the second mold assembly to heat to form a midsole preform, the midsole preform having a first groove formed about a periphery of the first portion, a second groove formed about a periphery of the second portion, and a third groove formed about a periphery of a third portion formed in the midsole preform;

placing the midsole preform in a second midsole recess in a fifth mold member of a third mold assembly;

placing the fifth mold member and a sixth mold member of the third mold assembly in contact with one another;

subjecting the midsole preform in the third mold assembly to heat and pressure to form a midsole;

removing the midsole from the third mold assembly; and

securing an outsole to the midsole.