US 11,700,911 B2
Shoe sole including laminate-structured midsole
Seigo Nakaya, Kobe (JP); Kenta Moriyasu, Kobe (JP); Yoshihito Tahira, Kobe (JP); Keishi Kitamoto, Kobe (JP); and Junichiro Tateishi, Kobe (JP)
Assigned to ASICS CORPORATION, Kobe (JP)
Appl. No. 17/52,123
Filed by ASICS CORPORATION, Kobe (JP)
PCT Filed May 18, 2018, PCT No. PCT/JP2018/019289
§ 371(c)(1), (2) Date Oct. 30, 2020,
PCT Pub. No. WO2019/220621, PCT Pub. Date Nov. 21, 2019.
Prior Publication US 2021/0227927 A1, Jul. 29, 2021
Int. Cl. A43B 13/12 (2006.01); A43B 13/04 (2006.01); A43B 13/18 (2006.01)
CPC A43B 13/127 (2013.01) [A43B 13/04 (2013.01); A43B 13/186 (2013.01); A43B 13/188 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A shoe sole comprising: an outsole having a tread surface; and a midsole arranged on the outsole, wherein:
the midsole includes an upper layer and a lower layer each of a foamed material;
the upper layer is a low-hardness foamed material having a thermoplastic resin component;
the lower layer is a high-hardness foamed material that has a thermoplastic resin component and has a high hardness that is higher than a hardness of the low-hardness foamed material;
the upper layer is seamlessly and integrally continuous from a posterior end portion of a rear foot portion to an anterior end portion of a forefoot portion;
the lower layer is seamlessly and integrally continuous from the posterior end portion of the rear foot portion to a posterior end portion of the forefoot portion;
a boundary line, which is a line of an anterior end of the lower layer and is an anterior-posterior boundary between the upper layer and the lower layer, is arranged at the posterior end portion of the forefoot portion;
in the forefoot portion, a lower surface of the upper layer includes a primary tread portion between a medial edge portion and a lateral edge portion of the midsole, and a line of a posterior end of the primary tread portion is defined by the boundary line;
in the primary tread portion of the forefoot portion anterior to the boundary line, an upper surface of the outsole is attached to the lower surface of the upper layer;
the low-hardness foamed material of the upper layer is made from a low-hardness, high-resilience material having a higher specific gravity than the high-hardness foamed material,
the low-hardness, high-resilience material having a low hardness that is lower than the hardness of the high-hardness foamed material, and
the low-hardness, high-resilience material having a higher speed at which to recover to an original shape after being deformed than that of the high-hardness foamed material,
at least in the forefoot portion, the lower layer is divided into a medial portion and a lateral portion;
a first edge on a central side of the lower layer of the medial portion and a second edge on the central side of the lower layer of the lateral portion are spaced apart from each other in a width direction;
at least in the medial portion, the lower layer forms a longitudinal arch extending in a front-rear direction, and the longitudinal arch has a lower surface that is depressed facing downward;
the first edge on the central side of the lower layer of the medial portion and the second edge on the central side of the lower layer of the lateral portion define a narrow slit extending in the front-rear direction from the forefoot portion to a position posterior to the longitudinal arch;
the upper layer is exposed uncovered by the lower layer through the slit;
at least in the middle foot portion, a ridge is provided on the lower surface of the upper layer, the ridge extending in the front-rear direction along the slit, the ridge fitting into the slit of the lower layer;
a first longitudinal groove extending in the front-rear direction is formed on the primary tread portion; and
the first longitudinal groove is formed anterior to the slit, and a posterior end of the first longitudinal groove and an anterior end of the ridge are continuous with each other in the front-rear direction.