SOCKLINER
A laminated foam sockliner for use in combination with footwear. The sockliner has a forward part generally underlying and supporting toes and metatarsal heads, a middle part generally underlying and supporting an arch, and a back part generally underlying and supporting a heel of the wearer. The sockliner includes a porous upper layer made from a flexible air permeable material. The upper layer provides support for at least a portion of the foot of the wearer including a heel and an arch of the foot. The sockliner also includes a shockfoam layer positioned generally at the back part of the sockliner below the upper layer. A top surface of the shockfoam layer being permanently bonded to at least a portion of a bottom surface of the upper layer underlying the back part of the sockliner. The forward part of the sockliner substantially lacks the shockfoam layer.
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The present invention generally relates to footwear and more particularly to footwear having a sockliner for cushioning a foot in the footwear.
BACKGROUND OF THE INVENTIONDuring walking and running, various portions of the foot impact the ground at different times resulting in certain parts of the foot being subjected to repeated impact forces. For instance, an outside portion of the heel experiences high impact forces during the initial heel strike phase of a gait cycle. These forces can transfer to other parts of the leg including the shins and knees. Over time, injury can result from these forces.
Foam sockliners are used to attenuate impact forces applied to the feet during walking and running. These liners are frequently made using a closed cell polyurethane or EVA (ethylene vinyl acetate) foam in a heel portion of the sockliner due to the ability of these types of foam to attenuate shock. Theses sockliners help to reduce the forces transferred to the feet. However, closed cell foam has limited durability and degrades over time eventually failing to provide adequate shock absorption.
SUMMARY OF THE INVENTIONIn one aspect, the present invention includes a laminated foam sockliner for use in combination with footwear for cushioning a foot of a wearer of the footwear. The sockliner has a forward part generally underlying and supporting toes and metatarsal heads of a wearer in use, a middle part generally underlying and supporting an arch of the wearer in use, and a back part generally underlying and supporting a heel of the wearer in use. The sockliner comprises a porous upper layer made from a flexible air permeable material. The upper layer has a top surface and a bottom surface opposite the top surface. The upper layer is sized and shaped to be inserted in the footwear and to provide support for at least a portion of the foot of the wearer including a heel and an arch of the foot. The sockliner also comprises a shockfoam layer positioned generally at the back part of the sockliner below the upper layer. The shockfoam layer has a top surface and a bottom surface opposite the top surface. The top surface of the shockfoam layer is permanently bonded to at least a portion of the bottom surface of the upper layer underlying the back part of the sockliner. The forward part of the sockliner substantially lacks the shockfoam layer.
In another aspect, the present invention includes a method of making a laminated foam sockliner for use in combination with footwear for cushioning a foot of a wearer of the footwear. The sockliner has a forward part generally underlying and supporting toes and metatarsal heads of a wearer in use, a middle part generally underlying and supporting an arch of the wearer in use, and a back part generally underlying and supporting a heel of the wearer in use. The method comprises molding an open cell foam upper layer to have a lower surface and an upper surface opposite the lower surface and to be sized and shaped to cover at least a portion of a sole of the footwear to underlie at least a portion of the foot of the wearer including a heel and an arch of the foot. A closed cell foam lower layer is molded to have a lower surface and an upper surface opposite the lower surface. The lower layer is sized and shaped to cover at least a portion of the foot of a wearer including at least the toes of the foot. The upper surface of the lower layer is bonded to the lower surface of the upper layer. A shockfoam layer is formed to a predetermined size and shape corresponding to a portion of the upper layer included in the back part of the sockliner. The method also includes bonding the shockfoam layer to the lower surface of the upper layer so the shockfoam layer is positioned below a portion of the upper layer and at the back part of the sockliner and not at the forward part of the sockliner.
In still another aspect, the present invention includes a laminated foam sockliner for use in combination with footwear for cushioning a foot of a wearer of the footwear. The sockliner has a forward part generally underlying and supporting toes and metatarsal heads of a wearer in use, a middle part generally underlying and supporting an arch of the wearer in use, and a back part generally underlying and supporting a heel of the wearer in use. The sockliner comprises a porous upper layer having a top surface and a bottom surface opposite the top surface. The upper layer is sized and shaped to be inserted in the footwear and to support at least a portion of the foot of the wearer including a heel and an arch of the foot. Further, the sockliner comprises a closed cell foam lower layer positioned generally at the forward part of the sockliner having a top surface and a bottom surface opposite the top surface. The lower layer is sized and shaped to be inserted into the footwear and to support at least a portion of the foot. The top surface of the lower layer is permanently bonded to the bottom surface of the upper layer. The sockliner also includes a nitrile butadiene rubber compound shockfoam layer positioned generally at the back part of the sockliner. The forward part of the sockliner substantially lacks the shockfoam layer.
Other objects and features will be in part apparent and in part pointed out hereinafter.
Corresponding reference characters indicate corresponding parts throughout the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTSReferring to the drawings and in particular
The sockliner 11 includes a porous upper layer 21 made from a flexible, air permeable material such as an open cell polyurethane foam. The upper layer 21 has a top surface 23 and a bottom surface 25 (
Referring to
Referring to
A shockfoam layer 43 is positioned generally in a back portion of the sockliner 11. The shockfoam layer 43 is positioned under the back part 17 and in some embodiments extends to a rearward portion of the middle part 15 of the sockliner 11. In other embodiments, the shockfoam layer 43 extends at least partially over the middle part 15 of the sockliner 11. The shockfoam layer 43 has a top surface 45 and a bottom surface 47. The top surface 45 is permanently bonded to the bottom surface 25 of the upper layer 21. In the illustrated embodiment, the shockfoam layer 43 is glued to the upper layer 21. The shockfoam material comprises a nitrile butadiene rubber compound having a C-type durometer hardness in a range from about 8 to about 10 and a density in a range from about 0.08 g/cc to about 0.11 g/cc. Although the shockfoam layer 43 may have other thicknesses without departing from the scope of the present invention, in one embodiment, the shockfoam layer has a thickness in a range from about 3 mm to about 4 mm. The shockfoam layer 43 provides the sockliner 11 with decreased weight and very good durability. The shockfoam layer 43 is positioned at the back part 17 of the sockliner 11 where durability is needed and less breathability can be tolerated.
Although the sockliner 11 may be made by other processes without departing from the scope of the present invention, in one embodiment, the open cell polyurethane foam is cut and molded to form the upper layer 21 and the closed cell polyurethane foam is cut and molded to form the lower layer 42. Next polyurethane gel is poured into the same mold that formed the lower layer 42 to form the raised pillow 33. Lastly, nitrile butadiene rubber is laminated to the upper layer 21, after the upper and lower layers 21, 42 are de-molded, to form the shockfoam layer 43 and a substantially complete sockliner 11.
Referring to
As illustrated in
As will be understood by those skilled in the art, although the shockfoam layer 43 has good cushioning properties, it generates heat from repeated compression during walking and running. The upper layer 21 spaces the shockfoam layer 43 from the foot to reduce heat transfer between the shockfoam layer and the foot and to insulate the foot from thermal energy generated by the shockfoam layers. Additionally, the shockfoam layer 43 is positioned at the back portion of the sockliner 11, away from the forward part 13, so breathability of the sockliner is not compromised in the forward arch and toe areas. The shock foam layer 43 maintains superior cushioning and durability under the heel of the foot where high impact loads are generated.
In the illustrated embodiments, the sockliner 11 comprises upper layer 21 and lower layer 42 similar to the upper layer and lower layer described in U.S. Pat. No. 6,199,304, entitled, “Sockliner”, which is incorporated by reference in its entirety. In other embodiments, the upper and lower layers of the sockliner 11 may have a unitary construction.
Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Claims
1. A laminated foam sockliner for use in combination with footwear for cushioning a foot of a wearer of said footwear, the sockliner having a forward part generally underlying and supporting toes and metatarsal heads of a wearer in use, a middle part generally underlying and supporting an arch of the wearer in use, and a back part generally underlying and supporting a heel of the wearer in use, the sockliner comprising:
- a porous upper layer made from a flexible air permeable material, said upper layer having a top surface and a bottom surface opposite the top surface, said upper layer being sized and shaped to be inserted in the footwear and to provide support for at least a portion of the foot of the wearer including a heel and an arch of the foot; and
- a shockfoam layer positioned generally at the back part of the sockliner below the upper layer, said shockfoam layer having a top surface and a bottom surface opposite the top surface, said top surface of the shockfoam layer being permanently bonded to at least a portion of the bottom surface of the upper layer underlying the back part of the sockliner, and said forward part of the sockliner substantially lacking the shockfoam layer.
2. A sockliner as set forth in claim 1 further comprising a closed cell foam lower layer positioned generally at the forward part of the sockliner and having a top surface and a bottom surface opposite the top surface, said lower layer being sized and shaped to be inserted into the footwear and to provide support for at least a portion of the foot, said top surface of the lower layer being permanently bonded to the bottom surface of the upper layer.
3. A sockliner as set forth in claim 2 wherein said back part of the sockliner entirely lacks the closed cell foam layer.
4. A sockliner as set forth in claim 2 wherein the lower layer includes a channel permitting air pass to cool and dry the foot.
5. A sockliner as set forth in claim 1 wherein at least a portion of the middle part of the sockliner entirely lacks the shockfoam layer.
6. A sockliner as set forth in claim 1 wherein the shockfoam layer comprises a nitrile butadiene rubber compound.
7. A sockliner as set forth in claim 5 wherein the shockfoam layer has a C-type durometer hardness from about 8 to about 10.
8. A sockliner as set forth in claim 6 wherein the shockfoam layer has a density from about 0.08 to about 0.11 g/cc.
9. A sockliner as set forth in claim 5 wherein the shockfoam layer has a density from about 0.08 to about 0.11 g/cc.
10. A sockliner as set forth in claim 1 further comprising a pillow positioned in the back part of the sockliner.
11. A sockliner as set forth in claim 9 wherein said pillow comprises a polyurethane gel positioned in an opening in the upper layer.
12. A sockliner as set forth in claim 10 wherein said pillow has a C-type durometer hardness from about 30 to about 35.
13. A sockliner as set forth in claim 11 wherein the pillow has a density from about 1.03 g/cc to about 1.04 g/cc.
14. A sockliner as set forth in claim 10 wherein the pillow has a density from about 1.03 g/cc to about 1.04 g/cc.
15. A sockliner as set forth in claim 1 wherein the upper layer comprises an open cell polyurethane foam.
16. A sockliner as set forth in claim 1 wherein the upper layer includes a channel permitting air to pass to cool and dry the foot.
17. A sockliner as set forth in claim 1 further comprising a cloth layer bonded to the upper surface of the base layer.
18. A method of making a laminated foam sockliner for use in combination with footwear for cushioning a foot of a wearer of said footwear, the sockliner having a forward part generally underlying and supporting toes and metatarsal heads of a wearer in use, a middle part generally underlying and supporting an arch of the wearer in use, and a back part generally underlying and supporting a heel of the wearer in use, the method comprising:
- molding an open cell foam upper layer to have a lower surface and an upper surface opposite said lower surface and to be sized and shaped to cover at least a portion of a sole of the footwear to underlie at least a portion of the foot of the wearer including a heel and an arch of the foot;
- molding a closed cell foam lower layer to have a lower surface and an upper surface opposite said lower surface, the lower layer being sized and shaped to cover at least a portion of the foot of a wearer including at least the toes of the foot;
- bonding the upper surface of the lower layer to the lower surface of the upper layer;
- forming a shockfoam layer to a predetermined size and shape corresponding to a portion of the upper layer included in the back part of the sockliner; and
- bonding the shockfoam layer to the lower surface of the upper layer so the shockfoam layer is positioned below a portion of the upper layer and at the back part of the sockliner and not at the forward part of the sockliner.
19. A method as set forth in claim 18 further comprising molding a gel insert into an opening in the upper layer.
20. A laminated foam sockliner for use in combination with footwear for cushioning a foot of a wearer of said footwear, the sockliner having a forward part generally underlying and supporting toes and metatarsal heads of a wearer in use, a middle part generally underlying and supporting an arch of the wearer in use, and a back part generally underlying and supporting a heel of the wearer in use, the sockliner comprising:
- a porous upper layer having a top surface and a bottom surface opposite the top surface, said upper layer being sized and shaped to be inserted in the footwear and to support at least a portion of the foot of the wearer including a heel and an arch of the foot;
- a closed cell foam lower layer positioned generally at the forward part of the sockliner and having a top surface and a bottom surface opposite the top surface, said lower layer being sized and shaped to be inserted into the footwear and to support at least a portion of the foot, said top surface of the lower layer being permanently bonded to the bottom surface of the upper layer; and
- a nitrile butadiene rubber compound shockfoam layer positioned generally at the back part of the sockliner, said forward part of the sockliner substantially lacking the shockfoam layer.
21. A sockliner as set forth in claim 20 wherein the shockfoam layer has a C-type durometer hardness from about 8 to about 10 and a density from about 0.08 to about 0.11 g/cc.
22. A sockliner as set forth in claim 21 further comprising a pillow positioned in the back part of the sockliner having a C-type durometer hardness from about 30 to about 35 and a density from about 1.03 g/cc to about 1.04 g/cc.
Type: Application
Filed: Aug 18, 2009
Publication Date: Feb 24, 2011
Applicant: NINE WEST DEVELOPMENT CORPORATION (White Plains, NY)
Inventor: John F. Ludemann (Southport, ME)
Application Number: 12/543,196
International Classification: A43B 7/06 (20060101); A43B 13/38 (20060101); A43D 11/00 (20060101);