AND FOOTWEAR SO MA5E

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to safety footwear and, more particularly, to an improved non-metallic toe guard for footwear, and to footwear incorporating such an improved toe guard.

2. The Prior Art

Toe guards, also known as toe boxes, have been known and in use for a long; time. In safety footwear, such as used by firemen, policemen, military men, sportsmen, outdoorsmen, construction workers, electrical workers, and steel workers, as opposed to conventional footwear worn in general, known toe guards typically are formed of a metal, such as steel, as by stamping and/or drawing, or the like. While for many applica¬ tions, such safety footwear, incorporating metallic toe guards, is satisfactory, it has its inherent drawbacks and limitations. Such drawbacks and limitations include excessive weight causing undue fatigue, high thermal conductivity causing the feet to become too hot or too cold, improper shape causing discomfort, corrosion causing premature aging of the footwear, electrical conduction risks such as are associated with electrical shocks, the detonation of land mines, the distortion or erasure of magnetic representations in data

processing memories, and high tooling costs which inhibit custom design. On the other hand, heretofore known non- metallic toe boxes as used in conventional safety footwear simply have lacked the required properties, particularly those involving strength as regards compression and impact resis¬ tance.

SUMMARY OF THE INVENTION

It is a principal object of the present invention to overcome the above disadvantages by providing an improved non-metallic toe guard for safety footwear and safety footwear incorporating such a toe guard. This toe guard possesses a chemical composition and a mechanical configuration that are characterized by a fortuitous combination of flex modulus, compression strength, and impact strength.

More specifically, it is an object of the present in¬ vention to provide an improved non-metallic toe guard for safety footwear and the safety footwear so made, which do not suffer from the drawbacks and the limitations of present day safety toe guards and safety footwear incorporating such safety toe guards. The non-metallic toe guard of the present invention is composed of a specific fiber-reinforced polymeric composite material, preferably a fiber reinforced composite material having the characteristics of light weight, corrosion resistance, low thermal conductivity and required high compression and impact resistance. Preferably, the composite toe guard of the invention is formed (1) with a bevel on

its inside top edge for greater comfort and for preventing injury to the foot of the wearer when the footwear is flexed,

(2) optionally increased front to back length providing increased protection for the foot of the wearer and extending rearwardly behind the toes, and, (3) optionally, no bottom flange, a bottom flange of selected width, or a full bottom flange extending all the way across the bottom of the footwear. Such a bottom flange, which characterizes the preferred embodiment, if made sufficiently wide, reduces or even eliminates any splay in the footwear that would otherwise be caused by compression or severe impact and establishes an integral floor which prevents the sole from "domeing" up when pressure or impact is applied to the top of the shoe. Unlike steel, which dents and/or deforms permanently when struck, the toe guard of the present invention, because of its "memory," returns substantially to its original shape. The flange or floor prevents the foot of the wearer from being locked in the impacted footwear so that it remains useable even after being exposed to repeated severe impacts or pressures. Preferably, the fiber reinforced composite compound includes a matrix or external phase composed of a polymeric material and a filler or internal phase composed of high tensile strength fibers embedded therein. The composite material in accordance with the present invention is a glass fiber filled linear polyamide. Footwear incorporating the improved toe guard of

the present invention includes boots and shoes made for and μsed by men, women, and children of any design and construction, including welted, cemented or injection molded.

Other objects of the present invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the improved non-metallic toe guard for footwear, and the footwear so produced, of the present disclosure, its components, parts and their interrelationships, the scope of which will be indicated in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and objects of the present invention, reference is to be made to the follow¬ ing detailed description, which is to be taken in connection with the accompanying drawings, wherein:

FIG. 1 is a partially cut away perspective view of a footwear incorporating an improved toe guard according to the present invention;

FIG. 2 depicts a portion of the footwear shown in FIG. 1 cut along the line 2 - 2;

FIG. 3 is a cross section of the improved toe guard shown in FIG. 1 along the line 2 - 2;

FIG. 4 is a fragmentary side elevational section of the footwear shown in FIG. 1 along the line 4 - 4;

FIG. 5 is a partially cut away perspective view of another footwear incorporating a different embodiment of an improved toe guard according to the present invention;

FIG. 6 is a cross section of the toe guard of FIG. 5 along the line 6 - 6;

FIG. 7 is a fragmentary portion of the footwear shown in FIG. 5;

FIG. 8 is a view similar to that shown in FIG. 7, but showing a further embodiment of an improved footwear according to the present invention; and

FIG. 9 is a cross section of still another footwear incorporating another embodiment of an improved toe guard according to the present invention;

Detailed Description of the Preferred Embodiment

In general, a footwear 10 made according to and incor¬ porating the present invention is illustrated in FIG. 1 as comprising an upper 12, a bottom 14 and a vamp 16, forming a toe 18. The footwear 10 as illustrated is a military boot. The invention equally is applicable to any and all types of safety footwear, including shoes and boots such as are used by firemen, policemen, sportsmen, hunters, surveyors, con¬ struction workers, electrical workers, steel workers, and the like. Further, and as will become more apparent from below, the footwear according to the invention can be of any known design and construction, including welted, cemented or

injection molded. The footwear 10 illustrated in FIGS. 1 and 2 is of the welted construction. An improved non-metallic toe guard 20 is shown as being incorporated in the toe 18 of the footwear 10. By being non-metallic, the improved toe guard 20 endows the footwear 10 with dielectric and non-magnetic properties, significantly reducing exposure of its wearer to electrical shock and the like.

The toe guard 20 is formed of a glass fiber filled linear polyamide composite material. This compound is characterized by being light in weight, non-corrosive and having a low thermal conductivity. The footwear 10 incorporating the improved non-metallic toe guard 20, therefore, occasions less wearer fatigue, resists the damaging effects_of salty envi¬ rons, and provides for better wearer comfort by better in¬ sulating the boot from outside temperature, be it hot or cold. Nevertheless, the improved non-metallic toe guard 20 provides the wearer of the footwear 10 incorporating it with as much, if not more, safety as heretofore exhibited by safety footwear featuring metallic, such as steel, toe guards. More specif¬ ically, the composite material of which the toe guard of the present invention is composed comprises an external phase consisting essentially of a linear polyamide such a 6-6 Nylon, and an internal phase consisting essentially of a refractory fiber such as fiberglass, the proportion of external phase polymer by total weight ranging from 40-70% and the proportion

of internal phase filler by total weight ranging from 60-30Z, and the density of the composite ranging from 1.27 to 1.65.

Preferably a majority of the glass fibers are at least 1 centimeter long, are composed of E-glass or F-glass, and are oriented at random with respect to each other.

EXAMPLE I

In one preferred example of the toe guard of the present invention, the external phase is 6-6 Nylon - 60% by total weight, the internal phase is E-glass fiberglass - 40% by total weight, the density of the 6-6 Nylon being approximately

1.14 grams per cubic centimeter, the density of the fiberglass being 2.54 grams per centimeter, and the density of the composite product being 1.50 grams per cubic centimeter.

Further details of such composite materials are disclosed in a

U.S. Patent 4,312,917 granted to Ronald C. Hawley on January

26, 1982, the disclosure of which is herewith incorporated by reference. Preferably, the starting fiberglass, linear polyamide composite is formed by extruding the linear polyamide along lengths of the fiberglass filler in such a way as to produce lengths of the composite, then chopping the lengths to size, typically producing pieces of 1 centimeter square, mixing the resulting pieces and compacting in a mold under pressure and heat ranging from 1,000 to 6,000 pounds per square inch and from 400 to 600°F. As a practical matter, the fiberglass is distributed in small groups, each having

-8- parallel fiberglass strands such that the strands in a given group are parallel, but the strands of different groups are at random angles with respect to other groups.

As shown in FIGS. 1 - 4, the improved non-metallic toe guard 20 is formed with a top portion 22, a front portion 24 and side portions 26 and 28. The top portion 22 and the side portions 26 and 28 define a first or upper edge 30 distal from the front of the toe, the edge 30 being provided with a first bevel 32. The front 24 and the side portions 26 and 28 also define a second or lower edge 34, with the edge 34 provided with a second bevel 36. As may be best observed in FIG. 4, the inclination of the first bevel 32 with respect to the adjoining portions of the rearward edge of the toe guard is of a gentler slope and lesser angle than that of the second bevel 36 with respect to the lower edge of the toe guard. Further, the first bevel 32 is formed on the inside, i.e., t p- side facing the foot of a wearer, while the second bevel 36 is formed on the bottom or outside, i.e., the side facing away from the foot of a wearer. Consequently, a potential source of discomfort, heretofore found to exist with some metallic toe guards, formed with a sharp steel edge on the inside top edge, has been eliminated. Such discomfort arose heretofore as a result of repeated flexing of the heavy leather upper along the length of this sharp steel edge. In metallic toe guards, an attempt was made to relieve this problem by

shortening the longitudinal length of the toe guard, in essence restricting it to the size of a toe cap only. This of course effectively reduced the area of protection provided by that type of safety shoe. In accordance with the present invention, because of the built-in inside top bevel 32 of the non-metallic toe guard 20, a longer top portion 22 thereof is now possible than heretofore, extending into the vamp portion 16, note FIGS. 1 and 4. In fact, a safety protection coverage of about 20% more of the foot now can be achieved than has been usual with metallic toe guards.

FIG. 3 illustrates a cross-section of the non-metallic toe guard 20 according to the invention and formed with no flange at the bottom. The footwear 10 illustrated in FIGS. 1 - 4 is of a welt construction, as best seen in FIGS. 2 and 4. The bottom 14 thereof is shown comprised of an outsole 38, a midsole 40, and a welt 42, all connected by a line of stitch¬ ing 44. Preferably, a filler 46 is disposed on the midsole 40, topped by a felt liner 48 and an inner sole 50, all as well known. Preferably, the footwear 10 also is provided with a lining 21.

In FIGS. 5 - 7, a footwear 56 of cement construction is illustrated. The illustrated footwear 56 is a cowboy boot and formed with an upper 58 and a bottom 60 forming a toe 62, with a non-metallic toe guard 64 incorporated in the toe 62. In FIG. 6, a cross-section of the non-metallic toe guard 64

according to the invention is shown being of the same composi¬ tion as toe guard 20 and as having a flange 76. Flange 76 is shown as extending throughout the bottom of the toe guard and as presenting a reentrant portion extending forwardly from the rearward edge. This particular cement construction includes a midsole 66 injection molded to the upper, and an outsole 68 cemented to the midsole 66 along a line 70 defining their interface. Further, the upper 58 preferably also is roughed and cemented as at 72, prior to its being injection molded with the midsole 66, observe FIG. 5 with the insole being omitted.

This embodiment of the non-metallic toe guard 64 also is provided with an inside top bevel edge 74 and differs essen¬ tially from the toe guard 20 merely in that it is provided with the flange 76 at the bottom thereof. In metallic toe guards, it has not been possible to provide such a wide flange, or sometimes indeed any flange at all since one can only draw steel so far. Consequently, when the resultant footwear has been exposed to compression or severe impact from the top, as by a heavy object falling on the footwear, severe splay often developed. Such severe splay not only rendered the footwear unfit for further use, but more importantly presented a danger that the wearer's foot might become locked in the impatted footwear. The non-metallic toe guard 64 of the invention, in contrast, can be formed with as wide a

flange 76 as desired. Generally, the wider the flange 76, the less the resultant splay.

FIG. 8 illustrates an injection molded footwear 80 having a bottom 82, injection formed in a suitable mold to an upper 84, preferably roughed and cemented, as at 86. Footwear 80 is provided with a non-metallic toe guard 88 having a bottom flange 90 and it is like toe guard 20 in composition.

In the construction of a footwear 100 illustrated in FIG. 9, a non-metallic toe guard 102 is like that shown in FIG. 8 in composition and in configuration except as follows. The toe guard 102 also is provided with a full bottom portion 104. The upper 106 is this time injection formed with a rubber bottom 108, however. Bottom 108 can be formed of natural or synthetic rubber, as contrasted with a preferred PVC bottom 82 for the footwear 80 illustrated in FIG. 8. An insole 109, is shown overlying the bottom portion 104 of the toe guard 106.

Thus it has been shown and described an improved non-metallic toe guard and footwear incorporating the same, which toe guard and footwear satisfy the object and advantages set forth above. Since certain changes may be made in the present disclosure without departing from the scope of the present invention, it is intended that all matter described in the foregoing specification or shown in the accompanying drawings, be interpreted in an illustrative and not a limiting sense.