WATERPROOF SAFETY FOOTWEAR
A waterproof safety article of footwear and preferably, but not exclusively, constructed with an outer shell formed from EVA (ethyl vinyl acetate) material, is described. It is comprised of an outer boot shell formed of waterproof material capable of being injection molded and an inner protective boot liner which is positioned inside the boot shell. The protective liner has a puncture proof insert, preferably a toe cap and sole plate secured thereto. The outer shell can also be molded from TPR (thermoplastic rubber) material. In order to achieve a maximum light weight safety article of footwear, the protective liner has a toe cap and a sole plate formed from composite materials and the outer shell is molded from EVA material. The method of constructing the waterproof safety article of footwear is also described.
The present invention relates to a waterproof safety footwear and a method of fabrication of same and wherein an inner protective boot liner is removably retained inside an outer waterproof boot shell and wherein the liner has a puncture proof toe cap and sole plate secured thereto. Preferably, but not exclusively, the outer shell is formed from EVA (ethylene vinyl acetate) material.
BACKGROUND ARTSafety footwear has been known for a very long time and such is usually used by construction workers in the form of leather boots in which is integrated a steel toe cap and sometimes, in combination, a steel sole plate. It is also known to fabricate safety protective boots made of rubber material such as thermoplastic rubber (TPR) and wherein a steel toe plate and a steel toe cap is encapsulated in the mold and molded in the rubber. A sock liner is first placed on an aluminum last before inserting the steel toe cap and steel plate. The metal pieces are retained in position on the aluminum last by magnets secured in the last. The mold is then closed and the thermoplastic material is injected. There are several problems associated with such fabrication.
Some of the problems with TPR molded boots is that they are expensive to fabricate due to the high percentage of rejects and labour costs. The molds are also expensive to produce. In an attempt to reduce cost boot rejects are usually cut open whereby to salvage the steel caps which is an expensive item in the manufacture of safety rubber boots. Because the steel plate is retained captive along the entire sole portion of the boot, it would be too labour intensive to try and salvage the plate and it is therefore discarded. Accordingly, there is extensive material loss involved with rejects as well as a loss in labour costs. The production cycle in the fabrication of such boots is also slow due to the fact that the sole plate and toe cap need to be assembled on the mold and encapsulated between liners. A further disadvantage of such rubber safety boots is that they are heavy due to the weight of the thermoplastic rubber as well as the weight of the steel toe cap and sole plate.
It is known to reduce the weight of waterproof articles of footwear by utilizing EVA (ethylene vinyl acetate) material which is waterproof and very light weight as compared with thermoplastic rubber. However, it is not possible to inject this material over a mold on which a steel sole plate and toe cap can be secured as the molding process of such articles of footwear utilizes molds which are of miniature dimension and the boot shell is formed by expansion of the injected material once the shell is removed from the mold. With this process, when the molded EVA shell is removed from the mold it starts expanding and it is immediately placed on a plastic last which is dimensioned to a desired size and the EVA shell is cured on the plastic last whereby to achieve a desired shape and size.
It would therefore be desirable to construct a waterproof safety footwear which is light weight and which could be made at lower production cost with a substantial reduction in the percentage of rejects associated with its manufacture.
SUMMARY OF INVENTIONIt is a feature of the present invention to provide a waterproof safety article of footwear which provides the above desired need and wherein the article of footwear can be made of light weight EVA material or TPR material with a substantial reduction in rejects and material and labour costs associated therewith.
Another feature of the present invention is to provide a light weight waterproof safety article of footwear constructed of an outer boot shell formed of EVA material and an inner protective boot liner removably retained therein and provided with a puncture proof protective insert which may be constructed of steel or light weight composite material.
Another feature of the present invention is to provide a waterproof safety article of footwear wherein the outer boot shell is formed from TPR material and further wherein an inner protective boot liner is removably retained inside the outer boot shell and provided with a puncture proof protective insert which may be constructed from steel or light weight composite materials.
Another feature of the present invention is to provide a method of constructing a waterproof safety article of footwear formed from an outer shell and an independent inner protective boot liner which is provided with a puncture proof protective insert to protect a portion of a wearer's foot and wherein the outer boot shell may be formed of light weight EVA material or TPR material.
According to the above features, from a broad aspect, the present invention provides a waterproof safety article of footwear comprising an outer boot shell formed of waterproof material capable of being injection molded. An inner protective boot liner is positioned inside the boot shell. The protective liner has a puncture proof protective insert to protect a portion of a wearer's foot. The puncture proof insert is independently secured to the protective liner.
According to a further broad aspect of the present invention there is provided a method of constructing a waterproof safety article of footwear which comprises the steps of injection molding an outer boot shell with a waterproof injectable material. An inner protective boot liner is formed from fabric material. A puncture proof protective insert is secured to the boot liner to protect a portion of the wearer's foot. The liner with its puncture proof protective insert is then inserted inside the boot.
The method also comprises forming the inner protective boot liner from thermally insulating fabric material and securing both a protective toe cap and a sole plate to the liner and wherein the sole plate and toe cap may be fabricated from either steel material or lighter weight composite materials.
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:
Referring now to the drawings and more particularly to
As herein illustrated with more specific reference to
With reference to
Having produced an inner protective boot liner 10 as above described and illustrated by
The outer boot shell 50 as shown in
In order to further reduce the weight of the waterproof safety article of footwear fabricated in accordance with the present invention, the toe cap 16 may be fabricated from a composite fiber material 25 as shown in
As shown in
Although the inner protective boot liner 10 as herein illustrated and described shows a protective toe cap and a protective sole plate secured to the liner it is intended that the present invention also cover a liner which is provided solely with a toe cap or solely with a protective sole plate depending on the requirements of the finished article of footwear. The outer boot shell may also be of a different construction than above-described. It is also pointed out that by fabricating the inner protective boot liner independently of the outer boot shell that better tolerances can be achieved in the protection of the sole portion of the safety article of footwear wherein the protective sole plate can be dimensioned to extend very close to the feather edge of the sole portion of the protective liner to about 4 mm from this feather edge 27 as illustrated in
Briefly summarizing the method of constructing the waterproof safety article of footwear 40 or 50 of the present invention it consists of injection molding an outer boot shell, such as the shell 40 and 50 in
It is within the ambit of the present invention to cover any obvious modifications of the examples of the preferred embodiment described herein provided such modifications fall within the scope of the appended claims.
Claims
1. A waterproof safety article of footwear comprising an outer boot shell formed of waterproof material capable of being injection molded, and an inner protective boot liner inside said boot shell, said protective liner having a puncture proof protective insert to protect a portion of a wearer's foot, said puncture proof insert being independently secured to said protective liner.
2. A waterproof safety article of footwear as claimed in claim 1 wherein said protective liner is removably retained inside said outer boot shell.
3. A waterproof safety article of footwear as claimed in claim 2 wherein said boot shell is a light weight injection molded shell formed of ethylene vinyl acetate (EVA) material.
4. A waterproof safety article of footwear as claimed in claim 2 wherein said puncture proof insert is a toe cap immovably secured to a toe portion of said boot liner.
5. A waterproof safety article of footwear as claimed in claim 4 wherein said puncture proof insert further comprises a sole plate immovably secured to a sole portion of said boot liner.
6. A waterproof safety article of footwear as claimed in claim 5 wherein at least one of said toe cap and sole plate is formed from one of a composite material or steel.
7. A waterproof safety article of footwear as claimed in claim 6 wherein both said toe cap or sole plate are formed from one of a composite material or steel.
8. A waterproof safety article of footwear as claimed in claim 6 wherein said toe cap and sole plate are secured to said protective boot liner by glue.
9. A waterproof safety article of footwear as claimed in claim 8 wherein said toe cap and sole plate are imprisoned in said protective boot liner between fabric material pieces which are stitched together along predetermined contour lines.
10. A waterproof safety article of footwear as claimed in claim 2 wherein said boot shell is a thermoplastic rubber (TPR) injected shell.
11. A waterproof safety article of footwear as claimed in claim 1 wherein said inner protective boot liner has a boot upper secured thereto, said outer boot shell being a boat-like shell, said liner being stitched to said boat-like shell.
12. A waterproof safety article of footwear as claimed in claim 6 wherein said sole plate extends to about 4 mm from a feather edge of the sole portion of said protective liner.
13. A waterproof safety article of footwear as claimed in claim 9 wherein said protective boot liner is constructed of felt material, said cap and sole plate being imprisoned between said felt material and an outer fabric retention liner secured to said felt material by stitching.
14. A method of constructing a waterproof safety article of footwear comprising the steps of:
- i) injection molding an outer boot shell with a waterproof injectable material;
- ii) forming an inner protective boot liner from fabric material;
- iii) securing a puncture proof protective insert to said boot liner to protect a portion of a wearer's foot; and
- iv) inserting said liner with said puncture proof insert inside said outer boot shell.
15. A method as claimed in claim 14 wherein said waterproof safety article of footwear is a light weight safety article of footwear, said step (i) comprising injection molding said outer boot shell with ethylene vinyl acetate (EVA) material.
16. A method as claimed in claim 14 wherein said step (iii) comprises immovably securing a sole plate to a sole portion of said boot liner.
17. A method as claimed in claim 16 wherein there is further provided immovably securing a toe cap to a toe portion of said boot liner.
18. A method as claimed in claim 17 wherein said toe cap and sole plate are secured by gluing same to said boot liner.
19. A method as claimed in claim 18 wherein said toe cap and sole plate are further imprisoned in said protective boot liner between fabric material pieces which are stitched together along predetermined contour lines.
20. A method as claimed in claim 14 wherein said step (i) comprises injection molding said outer boot shell with thermoplastic rubber (TPR) material.
Type: Application
Filed: Jul 10, 2007
Publication Date: Jan 15, 2009
Inventor: Pardo Vitulli (Riviere-des-Prairies)
Application Number: 11/775,254
International Classification: A43B 19/00 (20060101); A43B 23/07 (20060101); A43D 11/00 (20060101);