WATERPROOF BREATHABLE BOOT

Abstract

A waterproof breathable boot comprises a sole, at least two panels forming an external shell having an outer most surface waterproof, an internal layer separate from the outer shell and connected to the external shell by the sole such that a gap of air is formed between the internal layer and the external shell, and a drying insert connected to the internal layer. The at least two panels are waterproofly bonded to each other. An adhesive is in direct contact with a first portion of the inner surface and a second portion of the outer surface waterproofly for bonding the first portion to the second portion. The internal layer has wicking properties and is protected from an outside of the boot by the external shell. A method of manufacturing a waterproof breathable boot is also presented.

Description

TECHNICAL FIELD

The application relates generally to boots and, more particularly, to waterproof boots.

BACKGROUND OF THE ART

When working in humid environments, the boots have to fulfill two purposes: prevents water to pass therethrough, and remove humidity generated by the foot. Two types of boots are currently available. The first type is a leather boot. Leather boots are comfortable breathable boots with limited waterproof capabilities. Under repeated exposure to water the boot may become wet and may take a long time to dry. The boot may then become heavier due to the water accumulated in the leather. In cold weathers, the wet leather boot can even freeze.

The other type of boots are rubber boots. While rubber boots are perfectly waterproof, they do little for the evacuation of humidity generated by the foot. When rubber boots are used, it may become uncomfortable for the user to walk for hours with wet feet.

Some have proposed a leather boot with a waterproof inner liner to remedy to the deficiency of the above two types of boots. However the leather being water permeable, water may accumulate between the leather and the waterproof inner liner.

SUMMARY

In one aspect, there is provided a waterproof breathable boot comprising: a sole; an external shell having an outer most waterproof surface, the external shell extending to the sole and connecting thereto, the external shell including at least two panels, each panel having an outer surface and an inner surface, the outer surface of the at least two panels forming part of the outermost waterproof surface of the external shell, the outer surface and the inner surface of each panel being waterproof, the at least two panels being waterproofly bonded to each other, the waterproof bonding including an overlapping of a first portion of the inner surface of one of the at least two panels with a second portion of the outer surface of the other one of the at least two panels, an internal layer separate from the external shell and connected to the external shell by the sole such that a gap of air is formed between the internal layer and the external shell, the internal layer having wicking properties, the internal layer being protected from an outside of the boot by the external shell; and at least one drying insert, the internal layer carrying humidity from the wearer's foot to the drying insert, the drying insert being exposed to the outside of the boot.

In another aspect, there is provided a method of manufacturing a waterproof breathable boot, the method comprising: cutting at least two panels in a waterproof material having an outermost waterproof surface, the panels being cut in accordance to a pattern of the waterproof breathable boot; positioning at least one of the two panels onto a foot last and sewing adjacent sides of the panels forming a back of the boot so as to create a back seam; waterproofly bonding a back strap onto the back seam, the back strap being made of waterproof material; waterproofly bonding a portion of an inside of at least one other panel to a portion of an outside of the at least one of the two panels so as to form a vamp of the boot until forming a waterproof external shell, respective outer surfaces of the panels forming an outer most waterproof surface of the external shell; forming a wicking internal layer and disposing it inside the external shell; and securing the internal layer and the external shell to a sole thereby connecting the internal layer and the external shell to each other.

In accordance with a further general aspect, there is provided a waterproof breathable boot comprising: a sole; an external shell extending upwardly from the sole, the external shell having an outer most waterproof surface, the external shell including at least two panels having an outer surface and an inner surface, each panel having a multiply construction including at least one impermeable film laminated on a microfiber substrate, the impermeable film being provided at said outer surface of said at least two panels to form part of the outer most waterproof surface of the external shell, the at least two panels being waterproofly bonded to each other, the waterproof bonding including an overlapping of a first portion of the inner surface of one of the at least two panels with a second portion of the outer surface of the other one of the at least two panels; and an internal layer mounted in the external shell with a gap of air therebetween, the internal layer having wicking properties for carrying humidity away from the wearer's foot.

DESCRIPTION OF THE DRAWINGS

Reference is now made to the accompanying figures in which:

FIG. 1 is a side view of a waterproof breathable boot according to a first embodiment;

FIG. 1a is cross-section view taken along line 1a-1a in FIG. 1;

FIG. 2 is a schematic cross-section of a portion of an external shell of the boot shown in FIG. 1;

FIG. 3 is a schematic cross-section of a portion of the external shell and an internal layer of the boot shown in FIG. 1;

FIG. 4 is a waterproof breathable boot according to a second embodiment;

FIG. 5 is a waterproof breathable boot according to a third embodiment;

FIG. 6 is a waterproof breathable boot according to a fourth embodiment; and

FIG. 7 is a flow chart of a method of manufacturing the waterproof breathable boot.

DETAILED DESCRIPTION

The following description will be made with reference to a boot. It should be understood that any other foot accessory, such as a shoe, or bootie could be used instead of a boot. The boot/shoe/bootie may be used in a variety of environments including, none exclusively, street, mining, construction, backpacking, firefighting, hunting, military, leisure.

With reference to FIGS. 1 to 3, a waterproof breathable boot 10 will be described. The boot 10 includes a waterproof external shell 14 preventing fluid to permeate through the boot 10, and a wicking inner layer 13 transporting humidity formed in a foot portion 10a of the boot 10 toward a calf portion 10b of the boot 10 thereby rendering the boot 10 breathable.

The boot 10 includes a sole 12 which may be made of rubber and may have a pattern depending on the use of the boot 10. For a boot 10 to be used outdoors, the sole 12 may have a pattern to increase adherence to the ground. For street use, the sole 12 may have no pattern to be aesthetically pleasing.

The external shell 14 renders the boot 10 waterproof. The external shell 14 defines an exterior 17 of the boot 10 and an interior 18 of the boot 10. Thanks to the external shell 14 no fluid may communicate through the external shell 14 between the exterior 17 and the interior 18 of the boot 10, both ways. The external shell 14 may be directly connected to the sole 12 by, for example, gluing edges of the external shell 14 to the sole 12.

In the embodiment shown in the figures, the external shell 14 is made of two panels 14a, 14b. The external shell 14 could, however, be made of more than two panels. The panel 14a forms a vamp of the boot 10, while the panel 14b form a quarter of the boot 10. It is contemplated that the vamp of the boot 10 could not be unitary made, and be instead made of two or more pieces. The boot 10 could also include a foxing.

Referring more specifically to FIG. 2, the panels 14a, 14b are individually waterproof. An external surface 15a, 15b of the panels 14a, 14b is waterproof and an internal surface 16a, 16b of the panels 14a, 14b is also waterproof. The panels 14a, 14b may contain non-waterproof material between their external surfaces 15a, 15b and internal surfaces 16a, 16b. This could be the case when, for example, the panels 14a, 14b are made of two or more layers of material bonded to each other. The panels 14a, 14b could also be made entirely of waterproof material. In any case, water, humidity and vapor may not travel through the panels 14a, 14b both ways, as illustrated by arrows 20 and 21.

In one embodiment, the panels 14a, 14b are each made of a unitary piece of synthetic leather or polyurethane. However, it is understood that the panels 14a, 14b may be made of a waterproof material other than polyurethane.

According to another embodiment, each panel 14a, 14b is provided in the form of a multiply material comprising first and second layered structures bounded together, such as by an adhesive (e.g. a glue). Each layered structure may comprise a layer of microfiber (e.g. felt-like material) and a film of polyurethane or an equivalent film of water impermeable material laminated on at least one face of the microfiber layer. The material may be chosen more or less rigid depending on the use of the boot 10. For example, for street use, the material may be selected to be more flexible than for construction or mining use. The selection of the rigidity may be made via the selection of the material or by the selection of thickness of the material. The material and/or thickness of the material may also be chosen to resist to cuts and dents. Depending on the use of the boot 10, the material may be acid resistant, scratch resistant or fire resistant to name a few.

The panels 14a, 14b are waterproofly bonded to each other at bond 27. In one embodiment, an adhesive 22 bonds a portion (i.e. rim) of the internal surface 16a of the panel 14a to a portion (i.e. rim) of the external surface 15b of the panel 15b. In that embodiment, no sewing is needed, the adhesive 22 ensuring bonding and waterproofing of the connection between the panels 14a, 14b. Alternatively, a radio frequency (RF) bonding process may be used to bond the panels together.

As a result of choosing the panels 14a, 14b to be waterproof, and bonding them waterproofly, the external shell 14 has its outer most surface 24 waterproof. Waterproofing of the boot 10 is thus achieved at the outer most surface 24 of the boot 10. As such, water, humidity and vapor coming from the environment may be deflected off the outer most surface 24 upon contact with it, as illustrated by arrow 20 in FIG. 1. As a consequence, environment water may not accumulate on the boot 10 or in the boot 10 as it does in leather boots. In the embodiment shown in the Figures, the external shell 14 also has its inner most surface 23 waterproof which deflects water generated in the inside 18 of the boot 10 (as illustrated by arrow 21 in FIG. 3). It is however contemplated that the inner most surface 23 could be covered with a cloth such as felt

A rear 25 of the boot 10 may be sewn at seam 29 (shown in phantom in FIG. 1) and covered by a back strap 26. The panel 14b (or other panels if the boot 10 is made from more than two panels) may be brought side to side to form the rear 25 of the boot 10. The sides may be sewn to each other and covered by the back strap 26. The back strap 26 may be made of a same material as the panels 14a, 14b and may be adhesively secured to the panel 14b as per the various procedures described above. The back strap 26 covers the seam 24 such that the rear 25 of the boot 10 is waterproof.

Referring more specifically to FIG. 3, the inside 18 of the boot 10 includes the wicking internal layer 13 disposed adjacent to the external shell 14. The internal layer 13 may be directly connected to the sole 12 by, for example, gluing a lower rim of the internal layer 13 to the sole 12. The internal layer 13 may be connected to the external shell 14 solely at the sole 12 and at a rim 10e of the boot 10. The internal layer 13 may be sewn to the external shell 14 at the rim 10e of the boot 10. In other cases, the internal layer 13 may be sewn to the external shell 14 at discrete points on the boot 10.

Unlike the external shell 14, the internal layer 13 is not waterproof. The internal layer 13 is made of a material capable of absorbing humidity that may arise from the feet of the wearer at the foot portion 10a of the boot 10. The internal layer 13 may also wick or transport the humidity or water formed at the foot portion 10a toward the calf portion 10b of the boot 10. The internal layer 13 may not be attached to the inner most surface 23 of the external shell 14 such that a gap 32 of air is be formed between the external shell 14 and the internal layer 13. The gap 32 allows the internal layer 13 to dry faster than it would if glued to the external shell 14.

In one embodiment, the internal layer 13 is made of woven or non-woven fabric backed with a light foam. For instance, a material commercialized under the trade mark Cambrelle® could be used. The internal layer 13 may be backed or not with wicking foam. The foam may also be chosen to provide added comfort to the wearer. The internal layer 13 may be made of two or more layers of material, some may have wicking properties, and some may not. The internal layer 13 may be unitary made or made of panels sewn to each other. The internal layer 13 may be made of a material that is soft at the contact with the skin. The internal layer 13 may be formed of a single material or from a plurality of materials. For example, a first material may be used towards the foot portion 10a of the boot 10 and another material may be used toward the calf portion 10b of the boot 10.

As shown in dotted line in FIG. 1, the boot 10 may further include one or more reinforcing pieces 33 disposed between the external shell 14 and the internal layer 13. The reinforcing piece 33 may, for example, be a toe cap disposed at a toe portion 10c of the boot 10 to protect the toe of the user from being damaged by a heavy object. The reinforcing pieces 33 may also include a heel support disposed at a heel portion 10d of the boot 10 to provide support to the foot of the user. The reinforcing pieces 33 could be made, for example, of metal, plastic, fiber glass, leather, or thermoplastic depending on the application of the boot 10. The reinforcing pieces 33 may be disposed between the external shell 14 and the internal layer 13 during assembly of the boot 10, as will be described below, or may be connected, such as glued, to one of the external shell 14 and the internal layer 13.

As shown in FIG. 1a, the boot 10 may further include one or more pads 33a disposed between the external shell 14 and the internal layer 13. The pads 33a may be used to provide added comfort and foot support. The pads 33a may be made of foam and may be glued to the inner most surface 23 of the external layer 14.

Turning now to FIGS. 4 to 6, the boot 10 may be provided with drying inserts 34a and 34b to further enhance the drying capabilities of the boot 10. The drying inserts 34a, 34b may be located at the calf portion 10b of the boot 10 away from the sole 12 and the foot portion 10a in order to avoid contact with water coming from the environment. According to some applications (e.g. golf shoes) the drying insert could be disposed close to the sole 12.

The drying inserts 34a, 34b may be provided in the form of breathable membranes or fabrics impermeable to liquids but permeable to water vapor.

FIG. 4 shows a first embodiment of the drying insert 34a. The drying insert 34a is disposed in an aperture 36 or window defined in the external shell 14. The window may be defined in one of the panels with a die prior to assembling the external shell of the boot. The drying insert 34a may be bonded to the inner surface of the external shell so as to cover the aperture 36. The aperture 36 allows direct contact of the drying insert 34a with the outside 18 of the boot 10 (i.e. environment). The water vapor conveyed by the wicking liner 13 can be vented to the atmosphere through the drying inserts. The water vapor flows from the wicking liner 13 to the drying inserts 34a by diffusion.

FIG. 5 shows a second embodiment of the drying insert 34b. The drying insert 34b is similar to the drying insert 34a except that it is disposed in front of a cut-out 37 of the external shell 14.

FIG. 6 shows a third embodiment wherein a collar 34c of the internal layer 13 is exposed to the outside of the external shell, thereby allowing humidity to be exhausted away from the wearer's foot directly via the wicking internal layer 13. The collar may be bonded to a rim 38 of the external shell 14. The collar 34c may include a string 39 to tighten it around a calf of the user.

Turning now to FIG. 7, a method 50 of manufacturing of the boot 10 will be described.

The method 50 starts at step 52 with the formation of the external shell 14. The formation of the external shell 14 starts with cutting of the panels 14a, 14b in the waterproof material described above, and selecting the material in a manner described above. The cutting of the panels 14a, 14b may also include the formation of the window 36 or the cut-out 37. The drying insert 34a, 34b, 34c are positioned over the windows and bonded to the inner surface of the panels. The shape and size of the panels 14a, 14b may be dictated by a predefined pattern. Once the panels 14a, 14b are cut, they are waterproofly bonded to each other at the bond 27. As mentioned above, a suitable glue can be used to glue a portion (i.e. rim) of the panel 14a onto a portion (i.e. rim) of the panel 14b, such that the panels 14a, 14b have only a small overlapping portion. Pressure may be mechanically locally applied onto the bonding to solidify it in order to ensure waterproofness. The bonding described above results not only in a waterproof shell but also in an aesthetically pleasing boot, where the bond 27 provides a seamless effect.

Before the panels 14a, 14b are brought together to form the external shell 14, the pads 32 may optionally be glued to the inner most surface 23 of the external shell 14 according to a predefined pattern defining positions of the pads 32.

Once the panels 14a, 14b are bonded to each other, sides of the panel 14b are brought in a side-by-side relationship to form the seam 24. A boot last may be used to facilitate this operation. It is contemplated that the seam 24 could be made before the panel 14a is bonded to the panel 14b. The sides of the panels 14b are sewn to each other and thereafter the back strap 26 is waterproofly bonded to over the seam 24 in a manner described above. At the end of the above steps, the external shell 14 is formed. The external shell 14 at that stage has a general tubular shape.

From step 52, the method 50 goes to step 54, where the internal layer 13 is formed. It is contemplated that the internal layer 13 could be done before or at the same time as the external shell 14. The internal layer 13 is formed by sewing one or more pieces of the wicking material described above. The pieces to be sewn may be determined using a predefined pattern. If required by the predefined pattern, pads such as the pads 32 may optionally be sewn to a surface of the internal layer 13 which is to be facing the inner most surface 23 of the external shell 14. Once the internal layer 13 is formed, it has a general tubular shape. The internal layer 13 is then slid inside the external shell 14 and sewn to the rim 38 of the external shell 14.

The assembly formed by the internal layer 13 and the external shell 14 may be placed on the boot last. The reinforcing pieces 33 may be placed between the internal layer 13 and the external shell 14. Some may be secured by an adhesive or sewn to the external shell 14, other may just be placed between the internal layer 13 and the external shell 14.

From step 54, the method 50 goes to step 56, where the sole 12 is waterproofly glued to lower rims of the internal layer 13 and the external shell 14 so as to close the boot 10.

The above boot and method provide a light boot that is waterproof in both directions, and which at the same time allows an inside of the boot to dry relatively fast. The construction of the boot requires few steps and allows to manufacture the boot in a small amount of time. The construction of the boot also employs steps that are common to traditional boot manufacturing which allows to build this boot without major investment in new machinery and production methods. The boot may provide a compromise between leather boot which are breathable yet not waterproof and rubber boots which are waterproof but not breathable. The boot may be adapted to various environments ranging from city to outdoors and heavy duty. Because the waterproofing is obtained by the external shell and not by the internal layer, the addition of drying inserts is relatively easy. The multiply panel construction of the panels used to form the external shell allows to preserve the impermeability of the external shell even in the event of puncturing or ripping of the outermost layer of the shell.

The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.

Claims

1. A waterproof breathable boot comprising:

a sole;

an external shell extending and connected to the sole, the external shell having an outer most waterproof surface, the external shell including at least two panels having an outer surface and an inner surface, each panel having an outer surface and an inner surface, the outer surface of the at least two panels forming part of the outer most waterproof surface of the external shell, the outer surface and the inner surface of each panel being waterproof, the at least two panels being waterproofly bonded to each other, the waterproof bonding including an overlapping of a first portion of the inner surface of one of the at least two panels with a second portion of the outer surface of the other one of the at least two panels;

an internal layer separate from the external shell and connected to the external shell by the sole such that a gap of air is formed between the internal layer and the external shell, the internal layer having wicking properties, the internal layer being protected from an outside of the boot by the external shell; and

at least one drying insert integrated to the external shell, the internal layer carrying humidity from the wearer's foot to the at least one drying insert.

2. The waterproof breathable boot as defined in claim 1, wherein the external shell includes at least one layer of polyurethane.

3. The waterproof breathable boot as defined in claim 1, wherein the internal layer has a collar extending outwardly from an upper end of the external shell.

4. The waterproof breathable boot as defined in claim 1, wherein the at least one drying insert is mounted in a window defined in the external shell.

5. The waterproof breathable boot as defined in claim 1, further comprising a rear seam between the at least two panels, the rear seam extending upwardly from a heel portion of the external shell, the rear seam being covered by a back strap, the back strap being made of impermeable material and forming part of the external shell, an adhesive being in direct contact with the back strap and portions of the at least two panels covered by the back strap.

6. The waterproof breathable boot as defined in claim 1, wherein the at least one drying insert is made of a membrane or fabric impermeable to liquid but permeable to water vapor.

7. The waterproof breathable boot as defined in claim 1, wherein the external shell has an innermost surface, said innermost surface being impermeable, thereby providing for an external shell which is impermeable on both the inside and the outside.

8. The waterproof breathable boot as defined in claim 1, wherein a vamp of the boot is made of a single piece of one of the at least two panels.

9. The waterproof breathable boot as defined in claim 1, wherein the waterproof bonding further comprises an adhesive in direct contact with the first portion of the inner surface and the second portion of the outer surface for waterproofly bonding the first portion to the second portion.

10. A method of manufacturing a waterproof breathable boot, the method comprising:

cutting at least two panels in a waterproof material having an outermost waterproof surface, the panels being cut in accordance to a pattern of the waterproof breathable boot;

positioning at least one of the two panels onto a foot last and sewing adjacent sides of the panels forming a back of the boot so as to create a back seam;

waterproofly bonding a back strap onto the back seam, the back strap being waterproof;

waterproofly bonding a portion of an inside of at least one other panel to a portion of an outside of the at least one of the two panels so as to form a vamp of the boot until forming a waterproof external shell, an outer most surface of the external shell being waterproof;

forming a wicking internal layer and disposing it inside the external shell; and

securing the wicking internal layer and the external shell to a sole.

11. The method as defined in claim 10, further comprising locally applying pressure to the waterproof bonds.

12. The method as defined in claim 10, wherein forming the wicking internal layer comprises cutting portions of a wicking material and sewing them according to a pattern of the boot.

13. The method as defined in claim 10, further comprising mounting a drying insert in a window defined in the external shell.

14. The method as defined in claim 10, further comprising placing reinforcing pieces between the external shell and the internal layer.

15. The method as defined in claim 10, further comprising placing pads between the external shell and the internal layer and connecting the pads to at least one of external shell and the internal layer.

16. The method defined in claim 10, wherein the waterproof bonding is done using an adhesive.

17. A waterproof breathable boot comprising:

a sole;

an external shell extending upwardly from the sole, the external shell having an outer most waterproof surface, the external shell including at least two panels having an outer surface and an inner surface, each panel having a multiply construction including at least one impermeable film laminated on a microfiber substrate, the impermeable film being provided at said outer surface of said at least two panels to form part of the outermost waterproof surface of the external shell, the at least two panels being waterproofly bonded to each other, the waterproof bonding including an overlapping of a first portion of the inner surface of one of the at least two panels with a second portion of the outer surface of the other one of the at least two panels; and

an internal layer mounted in the external shell with a gap of air therebetween, the internal layer having wicking properties for carrying humidity away from the wearer's foot.

18. The boot defined in claim 17, wherein at least one drying insert is mounted in a window defined in the external shell at a location spaced from the sole, the internal layer carrying humidity from an area proximal to the sole to the at least one drying insert.

19. The boot defined in claim 17 wherein the microfiber substrate is laminated on both sides thereof with said impermeable film thereby providing at least two impermeable layers across a thickness of the external shell, a first one of the impermeable layer being provided at said outer most surface of the external shell and a second one of the impermeable layer being provided at an innermost surface of the external shell.