Heat-insulating lining for a footwear article and a footwear article including the same

Abstract

A heat-insulating lining for a footwear article includes an enclosure body made from an air-impermeable thermoplastic material and defining an inner space, and a porous layer disposed in the inner space such that the enclosure body encloses the porous layer intimately. The inner space in the enclosure body is in a vacuum state.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese application no. 200410098885X, filed on Dec. 20, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a heat-insulating lining for a footwear article, more particularly to a heat-insulating lining including an enclosure body defining an inner space in a vacuum state, and a porous layer intimately enclosed in the inner space of the enclosure body. This invention also relates to a footwear article including the heat-insulating lining.

2. Description of the Related Art

Heat-insulating fabrics, such as heat-insulating resin fabrics and glass fibers, are commonly used in footwear articles, such as an outsole, a lining, and an upper. While heat-insulating fabrics are useful for heat accumulation and insulation, they are unsuited for avoiding heat loss due to heat conduction, heat convection, and heat radiation when used in a cold environment. While heat loss can be reduced by increasing the fabric thickness, the increased fabric thickness will result in a corresponding increase in the size and weight of the footwear article. Physical motions of the wearer will be impeded accordingly.

Another conventional method for reducing heat loss of a footwear article is to stitch an aluminum foil layer and a heat-insulating resin fabric together, so as to diminish the heat radiation through the reflective property of the aluminum foil layer. However, since heat conduction and heat convection cannot be reduced through application of the aluminum foil layer, the footwear article made from this conventional method has a poor heat-insulating effect.

One conventional footwear article includes an upper having an upper enclosure that is lined with an inner lining sleeve by stitching. The inner lining sleeve is made from waterproof and breathable fabrics. The inner lining sleeve is capable of preventing intrusion of water into the interior of the footwear article. However, when the footwear article is used in a severely cold climate, pores of the inner lining sleeve will contract, and the moisture in the interior of the footwear article cannot be effectively expelled out to the exterior of the footwear article. Accordingly, the great temperature differential between the interior and the exterior of the footwear article results in condensation of the moisture in the interior of the footwear article. As cold air can permeate into the interior of the footwear article, water condensate in the interior of the footwear article can freeze. As a consequence, the footwear article loses its heat-insulating ability.

Another conventional footwear article includes an inner lining produced by the following steps: attaching respectively a fabric layer or heat-insulating resin layer to upper and lower surfaces of a plastic piece made from EVA or PU material, so as to form a pre-product; and cutting and stitching the pre-product so as to form an inner lining having a shoe shape. The inner lining thus made can be disposed in footwear articles, such as a shoe or a boot, to intimately enclose the foot of the wearer. However, although the inner lining can stop the cold air outside from permeating therethrough, gradual heat loss and condensate freezing attributed to heat conduction, heat convection, and heat radiation cannot be avoided.

Therefore, there is a need for a footwear article that is suitable for use in severely cold climates and that can minimize wearer discomfort attributed to heat conduction, heat convection and heat radiation.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a heat-insulating lining for a footwear article, and footwear articles including the heat-insulating lining that are clear of the aforesaid drawbacks of the prior art.

According to one aspect of this invention, includes an enclosure body made from an air-impermeable thermoplastic material and defining an inner space, and a porous layer disposed in the inner space such that the enclosure body encloses the porous layer intimately. The inner space in the enclosure body is in a vacuum state.

According to another aspect of this invention, a footwear article includes an outsole, an upper interconnected with the outsole so as to define a wearing space therebetween, and the heat-insulating lining as described above disposed in the wearing space and attached to the outsole.

According to still another aspect of this invention, a footwear article includes an outsole, an upper interconnected with the outsole so as to define a wearing space therebetween, the upper including a skin layer and an inner lining confronting the skin layer, and the heat-insulating lining as described above that is sandwiched between the skin layer and the inner lining of the upper and that is attached to the outsole.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:

FIGS. 1 and 2 respectively are inverted exploded perspective and schematic views to illustrate the first preferred embodiment of a heat-insulating lining for a footwear article according to this invention;

FIG. 3 is a schematic sectional view to illustrate the second preferred embodiment of a heat-insulating lining for a footwear article according to this invention;

FIG. 4 is a schematic sectional view to illustrate a structural modification of the second preferred embodiment shown in FIG. 3;

FIG. 5 is a schematic sectional view to illustrate the third preferred embodiment of a heat-insulating lining for a footwear article according to this invention;

FIGS. 6 and 7 respectively are perspective and fragmentary sectional views to illustrate the fourth preferred embodiment of a heat-insulating lining for a footwear article according to this invention;

FIG. 8 is a schematic sectional view to illustrate the first preferred embodiment of a footwear article according to this invention, which includes an outsole having the heat-insulating lining of FIG. 2 attached thereto; and

FIGS. 9 to 12 are fragmentary schematic sectional views to illustrate the second preferred embodiment of a footwear article according to this invention, which includes an upper integrated with the heat-insulating lining of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, the first preferred embodiment of a heat-insulating lining 100 for a footwear article according to this invention includes a porous layer 1 and an enclosure body 3. The enclosure body 3 is made from an air-impermeable thermoplastic material, and has an inner layer 31 and an outer layer 32. The inner and outer layers 31, 32 define an inner space 33. The porous layer 1 is disposed in the inner space 3 such that the enclosure body 3 encloses the porous layer 1 intimately.

Preferably, the air-impermeable thermoplastic material for preparing the enclosure body 3 is selected from the group consisting of nylon, polyethylene (PE), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), and combinations thereof.

The porous layer 1 is made from a porous elastic material. Preferably, the porous elastic material is selected from the group consisting of open-cell type polyurethane, polyesterresin, glass fiber, open-cell type polyethylene, open-cell type ethylene-vinyl acetate copolymer, and combinations thereof. More preferably, the porous elastic material is open-cell type polyurethane.

Preferably, the porous layer 1 further contains molecular sieve for moisture absorption, and active carbon for deodorization. In the preferred arrangement, the porous layer 1 has a top surface 13 and a bottom surface 14 opposite to the top surface 13. The bottom surface 14 has a honeycomb structure. The porous layer 1 is formed with a plurality of cavities 11 with a hexagonal section dented from the bottom surface 14, and a plurality of air channels 12, which have been magnified in FIG. 2 for ease of understanding, that pass through the porous layer 1 from the bottom surface 14 to the top surface 13 and that are in fluid communication with the cavities 11. The presence of the cavities 11 can reduce weight without sacrificing structural strength. The presence of the air channels 12 can stop heat conduction in the interior of the porous layer 1 attributed to air trapped therein. In addition, the porous elastic material used for manufacturing the porous layer 1 is preferred to have a black color so as to lower the heat-conductivity coefficient and to reduce heat loss attributed to heat radiation.

Preferably, the heat-insulating lining 100 further includes two reflecting layers 2 that are interposed between the outer layer 32 of the enclosure body 3 and the porous layer 1 and between the inner layer 31 of the enclosure body 3 and the porous layer 1, respectively. Each of the reflecting layers 2 is made from a metal material having low heat-conductivity so as to minimize heat radiation. Preferably, the metal material is aluminum foil.

During the manufacture of the heat-insulating lining 100 of this invention, the inner and outer layers 31, 32 of the enclosure body 3 are connected peripherally to each other, and an opening 34 in communication with the inner space 33 is formed therebetween. The porous layer 1 and the reflecting layers 2 are inserted into the inner space 33 through the opening 34. Thereafter, the inner space 33 is vacuumed using a vacuum pump (not shown) through the opening 34, and the opening 34 is subsequently sealed through a high-frequency welding technique or by a vacuum packaging machine, so as to keep the inner space 33 in the enclosure body 3 in a vacuum state. The enclosure body 3 is thus formed into an air-impermeable vacuum body.

FIG. 3 shows the second preferred embodiment of the heat-insulating lining 100 for a footwear article according to this invention. The second preferred embodiment is similar to the first preferred embodiment of this invention illustrated in FIGS. 1 and 2, except that a foam layer 5 and a fabric layer 4 are further included. In this embodiment, the enclosure body 3 has an outer surface with upper and lower sides formed from the inner and outer layers 31, 32, respectively. The foam layer 5 is attached to one of the upper and lower sides of the outer surface of the enclosure body 3. The fabric layer 4 is attached to the outer surface of the enclosure body 3 through the foam layer 5. The heat-insulating lining 100 of this embodiment is suitable for application to an insole.

FIG. 4 illustrates a structural modification of the second preferred embodiment of FIG. 3. In this embodiment, the foam layer 5 is attached to one of the upper and lower sides of the outer surface of the enclosure body 3. The fabric layer 4 is attached to the other of the upper and lower sides of the outer surface of the enclosure body 3, so that the enclosure body 3 is interposed between the fabric layer 4 and the foam layer 5.

The foam layer 5 used in the second embodiment shown in FIGS. 3 and 4 is made from an elastic and cushioning material, such as EVA, PU, or TPU.

When the heat-insulating lining 100 shown in either FIG. 3 or FIG. 4 is disposed in a footwear article, the inner space 33, which is in a vacuum state, does not promote air circulation. Hence, heat conduction and heat convection can be efficiently inhibited. In addition, the reflecting layers 2 that are interposed between the outer layer 32 of the enclosure body 3 and the porous layer 1 and between the inner layer 31 of the enclosure body 3 and the porous layer 1 can efficiently impede heat radiation. In addition, in view of the porous layer 1 being made from the porous elastic material, the contact area between the porous layer 1 and the reflecting layers 2 is decreased so as to further enhance inhibition of heat conduction and heat conduction. Therefore, the heat loss from the interior to the exterior of the footwear article can be minimize effectively.

As shown in FIG. 5, the third preferred embodiment of a heat-insulating lining for a footwear article according to this invention is similar to the embodiment illustrated in FIG. 4, except that a heat-insulating layer 50 is further included between the fabric layer 4 and the other of the upper and lower sides of the outer surface of the enclosure body 3, so that the fabric layer 4 is attached to the enclosure body 3 through the heat-insulating layer 50. The heat-insulating layer 50 is made from a foamed resin, such as heat-insulating resin, so as to enhance the heat-insulating effect of the heat-insulating lining.

FIGS. 6 and 7 illustrate the fourth preferred embodiment of a heat-insulating lining 6 for a footwear article according to this invention. The fourth preferred embodiment of this invention is similar to the first preferred embodiment of this invention illustrated in FIGS. 1 and 2, except that two foam layers 5 are attached to the upper and lower sides of the outer surface of the enclosure body 3, respectively.

In this embodiment, the heat-insulating lining 6 is formed into a shoe shape and is adapted to be inserted into a shoe. Particularly, the heat-insulating lining 6 includes a left upper portion 61, a right upper portion 62 and an outsole portion 63 connected to the left and right upper portions 61, 62 through a stitching or gluing technique.

Referring to FIG. 8, the first preferred embodiment of a footwear article according to this invention is illustrated. The footwear article of this embodiment includes an outsole 7, an upper 70 interconnected with the outsole 7, so as to define a wearing space therebetween, and the heat-insulating lining 100 shown in FIG. 2 that is disposed in the wearing space and that is attached to the outsole 7. Preferably, the outsole 7 is formed with a cavity 72 so as to receive fittingly the heat-insulating lining 100.

Referring to FIGS. 9 to 10, the second preferred embodiment of a footwear article according to this invention includes an upper 8 and an outsole 83. The upper 8 is interconnected with the outsole 83 so as to define a wearing space therebetween. The upper 8 includes a skin layer 81, an inner lining 82 confronting the skin layer 81, and a lining space 84 defined therebetween. The heat-insulating lining 100 shown in FIG. 2 is intimately sandwiched between the skin layer 81 and the inner lining 82 of the upper 8 in the lining space 84, and is attached to the outsole 83. Preferably, the heat-insulating lining 100 is peripherally stitched together with the skin layer 81 and the inner lining 82 of the upper 8 or is glued together with the skin layer 81 and the inner lining 82 of the upper 8. FIG. 10 is an enlarged view of a part of the upper 8 of the footwear article shown in FIG. 9.

Preferably, as shown in FIG. 11, the outsole 83 includes the heat-insulating lining 100 shown in FIG. 4, so as to enhance the heat-insulating effect of the footwear article. Alternatively, as shown in FIG. 12, the heat-insulating lining 100 extends with the inner lining 82 to enclosure the entire wearing space.

According to this invention, since the enclosure body 3 of the heat-insulating lining 100 is in a vacuum state, heat conduction, heat convection and heat radiation from the exterior to the interior of the heat-insulating lining 100 can be efficiently inhibited. In addition, by virtue of the porous layer 1 and vacuuming the enclosure body 3, the footwear article that includes the heat-insulating lining 100 can be maintained relatively lightweight.

While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation and equivalent arrangements.

Claims

1. A heat-insulating lining for a footwear article, comprising:

an enclosure body made from an air-impermeable thermoplastic material and defining an inner space; and

a porous layer disposed in said inner space such that said enclosure body encloses said porous layer intimately;

wherein said inner space in said enclosure body is in a vacuum state.

2. The heat-insulating lining for a footwear article as claimed in claim 1, wherein the air-impermeable thermoplastic material is selected from the group consisting of nylon, PE, TPU, PET, PVA, PAN, and combinations thereof.

3. The heat-insulating lining for a footwear article as claimed in claim 1, wherein said porous layer is made from a material selected from the group consisting of open-cell type polyurethane, polyester resin, glass fiber, open-cell type polyethylene, open-cell type ethylene-vinyl acetate copolymer, and combinations thereof.

4. The heat-insulating lining for a footwear article as claimed in claim 3, wherein said porous layer further contains molecular sieve and active carbon.

5. The heat-insulating lining for a footwear article as claimed in claim 1, wherein said porous layer has a surface with a honeycomb structure.

6. The heat-insulating lining for a footwear article as claimed in claim 1, further comprising a reflecting layer that is interposed between said enclosure body and said porous layer, said reflecting layer being made from a metal material having low heat-conductivity.

7. The heat-insulating lining for a footwear article as claimed in claim 6, wherein said metal material is aluminum foil.

8. The heat-insulating lining for a footwear article as claimed in claim 1, wherein said enclosure body has an outer surface with upper and lower sides, said heat-insulating lining further comprising a foam layer attached to one of said upper and lower sides of said outer surface of said enclosure body.

9. The heat-insulating lining for a footwear article as claimed in claim 8, further comprising a heat-insulating layer attached to the other of said upper and lower sides of said outer surface of said enclosure body.

10. A footwear article, comprising

an outsole;

an upper interconnected with said outsole so as to define a wearing space therebetween; and

a heat-insulating lining disposed in said wearing space and attached to said outsole, said heat-insulating lining including an enclosure body made from an air-impermeable thermoplastic material and defining an inner space, and a porous layer disposed in said inner space such that said enclosure body encloses said porous layer intimately;

wherein said inner space in said enclosure body is in a vacuum state.

11. The footwear article as claimed in claim 10, wherein said outsole is formed with a cavity so as to receive fittingly said heat-insulating lining.

12. The footwear article claimed in claim 10, wherein said porous layer further includes molecular sieve and active carbon.

13. The footwear article as claimed in claim 10, wherein said porous layer has a surface with a honeycomb structure.

14. The footwear article as claimed in claim 10, wherein said heat-insulating lining further includes a reflecting layer that is interposed between said enclosure body and said porous layer, said reflecting layer being made from a metal material having low heat-conductivity.

15. The footwear article as claimed in claim 14, wherein said metal material is aluminum foil.

16. The footwear article as claimed in claim 10, wherein said enclosure body has an outer surface with upper and lower sides, said heat-insulating lining further including a foam layer attached to one of said upper and lower sides of said outer surface of said enclosure body.

17. A footwear article, comprising

an outsole;

an upper interconnected with said outsole so as to define a wearing space therebetween, said upper including a skin layer and an inner lining confronting said skin layer; and

a heat-insulating lining that is sandwiched between said skin layer and said inner lining of said upper and that is attached to said outsole, said heat-insulating lining including an enclosure body made from an air-impermeable thermoplastic material and defining an inner space, and a porous layer disposed in said inner space such that said enclosure body encloses said porous layer intimately;

wherein said inner space in said enclosure body is in a vacuum state.

18. The footwear article as claimed in claim 17, wherein said porous layer has a surface with a honeycomb structure.

19. The footwear article as claimed in claim 17, wherein said heat-insulating lining further includes a reflecting layer that is interposed between said enclosure body and said porous layer, said reflecting layer being made from a metal material having low heat-conductivity.

20. The footwear article as claimed in claim 17, wherein said metal material is aluminum foil.