US20170188658A1 - Safety footwear - Google Patents

Abstract

A method of constructing footwear includes providing a mold having an inner cavity, injecting an expandable material into the inner cavity, removing the expandable material from the inner cavity such that the material expands to form a footwear-shaped shell having an inner cavity and at least one recessed area offset from an inner surface of the shell, and inserting a chassis within the inner cavity of the expanded shell. The chassis has one or more components adapted to protect a user's foot from injury. The insertion of the chassis within the shell permanently affixes the one or more components within the at least one recessed area of the shell.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a divisional application of U.S. application Ser. No. 14/208,037, filed on Mar. 13, 2014, which claims the benefit of U.S. Provisional Patent Application No. 61/779,054, filed Mar. 13, 2013, the disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
• The present invention(s) relates, in general, to safety footwear for use in harsh conditions, such as in a variety of agricultural, food processing, energy exploration, industrial, and/or hazmat environments.
• Footwear developed to withstand harsh conditions, such as conditions in which the wearer is subject to constant exposure to water, chemicals, hot or cold temperatures, or natural corrosives, must be constructed to withstand those conditions while maintaining comfort for the wearer. A common area in which certain footwear is subject to one or more of the foregoing environments is, for example, in the oil drilling industry. Currently, drilling platforms may be in an environment in which the ground or working area is constantly muddy, laced with chemicals or corrosive additives used during drilling, or both. Fracking (or hydraulic fracturing) is a practice in the drilling industry in which the aforementioned conditions are commonly present. In such harsh working conditions, footwear often degrades or deteriorates entirely within a short period of time, subjecting the user to unnecessary costs in purchasing footwear at short intervals. For example, certain footwear available in the current market may only last for a period of two (2) or three (3) weeks in such conditions.
• It is also the case that, with working conditions such as those encountered in the drilling industry, safety is paramount. Indeed, certain standards (e.g., those prescribed by the American Society for Testing and Materials (ASTM), CSA, or EN-ISO) require that footwear used within these industries meet numerous safety requirements. As an example, any safety components introduced into the footwear must be integral to the construction of and non-removable from the footwear; or in other words, the user cannot remove the safety components once the footwear is purchased. Other safety requirements are also present, of course.
• Further, solid elastomer and/or rubber footwear currently used in the above-noted environments tend to be heavy; and, since footwear weight and flexibility are factors that impact human ambulation efficiencies and/or the amount of energy expended during normal work shifts, these considerations may be significant. For example, heavy and/or non-flexible footwear may increase worker fatigue as compared to if lighter and/or more flexible footwear was used.
• Particular methods of manufacturing footwear are also known in the industry, one of those being a method in which expandable polymeric materials (e.g., polyolefin elastomers (PE), ethylene-vinyl acetate (EVA), or other such materials) are used. In short, expandable polymeric materials may be placed into an injection mold and formed into various footwear-type components. However, to date, incorporating such expanding footwear with industry and government regulated safety footwear performance features, as outlined in recognized Occupational Standards Bodies (ASTM F2413 and CSA Z195, for example), has not been possible.
• Given the foregoing, there exists a need for lightweight footwear that can withstand harsh environments while providing ample safety for the user in those environments.
BRIEF SUMMARY OF THE INVENTION
• Aspects of the present invention(s) provide footwear that can withstand harsh environments while providing ample safety for the user in those environments.
• As an example, a first aspect of the invention(s) includes a footwear system comprising a shell having an inner cavity and at least one recessed area offset from an inner surface of the shell, and a chassis having one or more components adapted to protect a user's foot from injury, the chassis being insertable into the inner cavity of the shell, such that the one or more components of the chassis are permanently affixed within the at least one recessed area of the shell. In variants of this aspect, each recessed area also includes a set of stop surfaces arranged at an angle to the inner surface of the shell, and each component includes corresponding stop surfaces adapted to engage with the stop surfaces of the shell to retain the component within the recessed area. In some cases, the shell may also be composed of a corrosive-resistant material, or a material selected from the group consisting of a polyolefin elastomer, ethyl vinyl acetate, an expandable polymer, or a co-polymerized material suitable for cross-link foaming in a post-injection expandable foaming process. Further, the chassis may include a toe cap composed of rigid material, a heel counter, an insole board engaged to the top cap and heel counter, and/or a metatarsal guard.
• A second aspect of the invention(s) is a method of constructing footwear comprising the steps of: (1) providing a mold having an inner cavity; (2) injecting an expandable material into the inner cavity; (3) removing the expandable material from the inner cavity, such that the material expands to form a footwear-shaped shell, the shell having an inner cavity and at least one recessed area offset from an inner surface of the shell; and (4) inserting a chassis within the inner cavity of the expanded shell, the chassis having one or more components adapted to protect a user's foot from injury, wherein insertion of the chassis within the shell permanently affixes the one or more components within the at least one recessed area of the shell. In embodiments of this aspect, inserting the chassis within the inner cavity of the shell comprises positioning a stop surface of the one or more components so that it interferes with a stop surface arranged adjacent the at least one recessed area. The shell may also comprise a material impermeable to water or other solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
• A more complete appreciation of the subject matter of the present invention(s) and of the various advantages thereof can be realized by reference to the following detailed description in which reference is made to the accompanying drawings in which:
• FIGS. 1A-C are cross-sectional views of a footwear system, according to one embodiment of the present invention(s).
• FIGS. 2A-C are cross-sectional views of a variant of the footwear system ofFIGS. 1A-C.
• FIGS. 3A-C are cross-sectional views of yet another variant of the footwear system ofFIGS. 1A-2C.
• FIGS. 4A-C are cross-sectional views of the shell of yet another variant of the footwear system ofFIGS. 1A-3C.
• FIGS. 5A-B are cross-sectional views of the shell and chassis of still yet another variant of the footwear system ofFIGS. 1A-4C.
DETAILED DESCRIPTION
• In describing certain features of the present invention(s), specific terminology will be used for the sake of clarity. However, the invention(s) is not intended to be limited to any specific terms used herein, and it is to be understood that each specific term includes all technical equivalents, which operate in a similar manner to accomplish a similar purpose.
• Referring toFIGS. 1A-C, such depictsfootwear10 being composed of a number of components, namely anouter shell20 and an assembledchassis50 inserted and secured into theshell20.FIGS. 1A-B depict, in detail,outer shell20 andchassis50, the latter of which may itself include a number of components, particularly: (1) a safety toe box orcap52; (2) a punctureresistant insole board66; (3) ashock diffusion plate76; and (4) aheel counter86. Other components may also form part ofchassis50, as set forth in additional embodiments discussed below. Nonetheless, in each embodiment,chassis50 may be inserted intoshell20 and secured thereto so that a user may not removechassis50. In this manner,footwear10 may provide safety for a user in certain dangerous or harsh environments (e.g., in the drilling industry).
• As shown inFIG. 1B, in oneembodiment chassis50 may include atoe cap52 having inner andouter surfaces54,56, thetoe cap52 being arrangeable over a user's forefoot region to protect the user's toes from injury due to an impact or other event. Indeed,toe cap52 may be formed of rigid material, such as a hard polymer, metal, or other material, and include asection58 overlying a user's toes. Toecap52 may also include alower protruding section62, in this embodiment, that is connected at itsinner surface54 toinsole board66, as discussed below. Lastly,toe cap52 may includestop surfaces60,64 for engaging with certain stop surfaces inouter shell20.
• Referring still toFIG. 1B,chassis50 may include, as alluded to above, aninsole board66 that in some cases is puncture resistant.Insole board66 may have inner andouter surfaces68,70 andends72,74, which are connected at theirouter surface70 totoe cap52 andheel counter86, respectively.
• Heel counter86 may likewise include inner and outer surfaces88,90, and alower protruding section92 for engaging withinsole board66. Heel counter86 may also provide rigidity tochassis50 at that section so that, when a user inserts his/her foot intofootwear10, stability is provided in the heel region. As withtoe cap52,heel counter86 also has stop surfaces94,96 for engaging with corresponding stop surfaces inshell20.
• Chassis50 further includes ashock diffusion plate76 in this embodiment (FIG. 1B) that overliesinsole board66.Shock diffusion plate76 may, if desired, take the form of tuck board-type material (e.g., standard footwear cellulose, or entangled non-woven or woven-type materials, with or without stiffening agents) that is rigid in nature so as to absorb any shock or force impacted oninsole board66. In an alternate embodiment,shock diffusion plate76 may be any of the shock diffusion plates shown and described in U.S. Pat. No. 6,205,683 to Clark et al., owned by The Timberland Company, the disclosure of which is hereby incorporated herein by reference. Together, the aforementioned components create one embodiment ofchassis50 that is insertable intoshell20 in the manner discussed below.
• Shell20, as shown inFIG. 1A, may include several aspects common to typical footwear, such as anoutsole22, an upper24, andheel26,forefoot28, andinstep30 sections. In one embodiment,shell20 is also impermeable to certain substances, such as water, mud, or other solutions or corrosives.Shell20 may also include aninner cavity21 shaped to accommodate a user's foot, which has various recessed areas orcutouts31,32 for receiving a portion ofchassis50. In one embodiment, recessedareas31,32 may be bounded by stop surfaces34 on either side to receive and securely hold a portion ofchassis50 within the relevant recessedarea31,32. In a particular embodiment, as shown inFIG. 1A,shell20 may include two (2) recessedareas31,32 for accommodatingtoe cap52 andheel counter86 therein, although more or less recessed areas may be employed.
• As shown inFIG. 1C, to constructfootwear10,chassis50 may be inserted intoshell20, such thattoe cap52 is situated in recessedarea31 ofshell20, andheel counter86 is likewise situated in separate recessedarea32. Once so inserted intoshell20, stopsurface64 oftoe cap52 and stopsurfaces94,96 ofheel counter86 may contact respective stop surfaces34 surrounding recessedareas31,32 ofshell20 so thattoe cap52,heel counter86, and thuschassis50 are securely retained withinshell20. While not shown inFIG. 1C, in oneembodiment stop surface60 may also contact analternate stop surface34 within shell20 (e.g., recessedarea31 may be made to be smaller so that astop surface34 of recessedarea31 contacts stopsurface60 to retaintoe cap52 within shell20).
• To ensure thatchassis50 is not removable fromshell20, in compliance with safety standards, it is possible to cement or otherwise adhere certain portions ofchassis50 to shell20 (e.g., the whole ofchassis50 or, for example, only insoleboard66 may be cemented or adhered to shell20). Alternatively, it is contemplated thatchassis50 may snap into place withinshell20 so thatchassis50 is non-removable therefrom. In other words, during insertion ofchassis50 withininner cavity21 ofshell20, a user may press-fit toe cap52 andheel counter86 within recessedareas31,32, such thatchassis50 is retained withinshell20 due to interference between stop surfaces34,64,94,96 (and in an alternate embodiment, stop surface60). This may be achieved by manufacturingchassis50 so that a dimensional interference is created betweenchassis50 and shell20 (e.g., certain portions ofchassis50, such astoe cap52 andheel counter86, may be arranged so that such portions can be press-fit into recessedareas31,32). As an example, stopsurface64 ontoe cap52 and stopsurface94 onheel counter86 may be separated by a first distance, which is slightly less than a second distance separating stop surfaces34 of recessedareas31,32 that contact stop surfaces64,94. In this manner, oncechassis50 is inserted intoshell20, stop surfaces64,94 may be forced past stop surfaces34 of recessedareas31,32 to securely lockchassis50 in place (e.g., via a dimensional interference).
• Withchassis50 inserted intoshell20, as discussed above,toe cap52 may adequately ensure that a user's toes are not injured due to an impact event (e.g., an object striking the toes),insole board66 may provide puncture resistance,shock diffusion plate76 may diminish or absorb any impact forces borne on the foot, andheel counter86 may provide support for a user's heel during use. In addition,shell20 may provide corrosion resistance and/or impermeability with respect to several substances (e.g., water, mud, corrosive liquids/chemicals, etc.)
• It is also contemplated that shell20 (or any of the alternate shells described below) may be manufactured from particular corrosion-resistant materials, such as cross-linking post-injection expansion polyolefin elastomers. As an example,shell20 may be manufactured through an injection-molding process that uses expandable polymers, such as EVA. In short, during such a process, a mold may be injected with EVA or EVA-type material to formshell20, and once appropriately cured,shell20 may be released from the mold into the configuration shown inFIG. 1A (or any of the remaining figures depicting alternate embodiments of shell20). The curing process may be controlled by subjectingshell20 to engineered expansion (e.g., controlling ambient conditions, temperature, time, etc.)
• Stated differently, as injected into the mold,shell20 may be relatively smaller than in its final configuration (FIG. 1A), and once released,shell20 may expand to its final state. Then, aftershell20 has been released from the mold and allowed to expand to its final form (FIG. 1A, or the other figures depicting the shell),chassis50 may be inserted into and secured withinshell20 in the manner discussed previously. As such, through this process, it is possible to manufacturefootwear10 meeting the various requirements mandated in certain industries (e.g., the non-removability of safety components), such as in the drilling industry. In addition,footwear10 utilizing the aforementioned features not only provides comfort for the user, along with safety, but also lasts far longer in corrosive environments than other existing arrangements. As such, within these industries, the consumer is not forced to purchasefootwear10 at exceedingly short intervals of time.
• An alternate version offootwear10 is shown inFIGS. 2A-C, in whichchassis50 andshell20 are slightly modified. Here, like numerals refer to like elements, except where indicated (although reference numerals are in the 100-series instead of, as an example, the 10-series).
• Referring toFIG. 2B,chassis150 is generally the same aschassis50, except thatchassis150 includes ametatarsal guard198.Metatarsal guard198 may have respective inner andouter surfaces200,202 and anend206 that connects withtoe cap152. In one embodiment, end206 includes an L-shaped groove that connects withtoe cap152 so that both components are an integral unit forming part ofchassis150. In some cases,metatarsal guard198 may take the form of any of the metatarsal guards shown or otherwise described in U.S. patent application Ser. No. 13/648,839 (the '839 Application), entitled “Protection Devices for Use in Shoes or Other Products,” the disclosure of which is hereby incorporated by reference herein. As taught in the '839 Application, a metatarsal guard, such asmetatarsal guard198, may be positioned over the metatarsal region of a user's foot to protect the same from injury. In particular, as shown inFIG. 2C,metatarsal guard198 may be positioned withininstep130 ofshell120 to overlie the metatarsal region of the user's foot.
• FIG. 2A depictsshell120 as having a recessedarea131 that extends from a portion of afloor136 ofshell120adjacent forefoot end128 to a section ofshell120adjacent instep130. Thus, in this embodiment, recessedarea131 may be designed specifically to accommodatemetatarsal guard198 andtoe cap152, in combination. Recessedarea132 may be of the same configuration and shape as recessedarea32 of the previous embodiment ofshell20 so thatheel counter186 may be received within such recessedarea132.Metatarsal guard198 may also include a stop surface204 (FIG. 2B) that engages withstop surface134 bordering recessedarea131 upon insertion ofchassis150 withinshell120.
• Much like the previous embodiment, to assemblefootwear110,chassis150 may be inserted withininner cavity121 ofshell120 so thatheel counter186 is received within recessedarea132, andmetatarsal guard198 andtoe cap152 are received within recessedarea131. In particular, stop surfaces194,196 ofheel counter186 may engage withstop surfaces134 of recessedarea132 to secureheel counter186 within recessedarea132, and stop surface164 oftoe cap152 and stopsurface204 ofmetatarsal guard198 may engage withstop surfaces134 of recessedarea131 to securetoe cap152 andmetatarsal guard198 within recessedarea131. In one embodiment, the aforementioned components of chassis150 (e.g.,heel counter186,toe cap152, and metatarsal guard198) may also be cemented or adhered within recessedareas131,132 so thatchassis150 may be non-removable fromshell120. Alternatively, it is contemplated thatchassis150 may simply snap into place within recessedareas131,132, such thatchassis150 is not removable fromshell120, as detailed more fully above. Indeed, as an example, a distance between stop surface164 oftoe cap152 and stopsurface204 ofmetatarsal guard198 may be greater than a distance between stop surfaces134 of recessedarea131, such thattoe cap152 andmetatarsal guard198 may be press-fit into recessedarea131. The same may be true forheel counter186 and recessedarea132, in one embodiment.
• Referring toFIGS. 3A-C, an alternate embodiment offootwear10,110, namelyfootwear310, is shown. As with above, like numerals refer to like elements in this embodiment, although in the 300-series instead of, as an example, the 10-series.
• As shown inFIG. 3B,chassis350 is generally the same as chassis50 (FIGS. 1A-C), except thatchassis350 may include aninsole410 that is specifically configured to be puncture resistant (e.g., via being composed of rigid material(s), such as metal, hard plastics or composites, etc.) Thus, althoughinsole board366 may have puncture-resistant characteristics as well,insole410 may provide yet additional puncture resistance tochassis350. Referring toFIG. 3B,insole410 may have inner andouter surfaces412,414 and respective toe and heel ends416,418, theouter surface414 ofsuch ends416,418 being bonded, respectively, to lower protrudingsection362 oftoe cap352 and lower protrudingsection392 ofheel counter386. As such,insole410 may overly theinner surfaces354,388 of lower protrudingsections362,392 oftoe cap352 andheel counter386, respectively.
• Referring now toFIG. 3A,shell320 in this embodiment may be generally identical to theprevious shells20,120 so as to accommodatechassis350. Thus, the assembly offootwear310, as shown inFIG. 3C, may proceed substantially as discussed above with respect tofootwear10 ofFIGS. 1A-C (with the addition of added puncture resistance via insole410). As such,chassis350 may be non-removable fromshell320, as in previous embodiments, so thatfootwear310 satisfies certain safety requirements of various recognized regulatory bodies.
• A further variant offootwear10,110,310 may be provided, theshell520 of which is shown inFIGS. 4A-C. In this embodiment, as shown inFIG. 4A, thefootwear shell520 may include anopening538. Opening538 may be shaped to accommodate an outsole522 (FIG. 4B) that is applied to shell520 after manufacture thereof. Thus, opening538 may be specifically configured to accommodate outsole522.
• For example, as shown inFIG. 4B, outsole522 may include a set offlanges540,542 and stopsurfaces544,546 adjacentsuch flanges540,542; and, to fully constructshell520, outsole522 may be inserted throughopening538, such thatflanges540,542 engage correspondingflanges547,548 of shell520 (FIG. 4A) and stopsurfaces544,546 engage respective stop surfaces543,545 formedadjacent flanges547,548 ofshell520. The engagement betweenshell520 and outsole522 is shown in detail inFIG. 4C. Thus, outsole522 may be securely retained withinshell520 post-manufacture ofshell520. Indeed, in one embodiment, outsole522 is cemented to shell520, or adhered via an adhesive, chemical bonding, etc.
• Once adhered to shell520, outsole522 may serve to create the same configuration as the previously-describedshells20,120,320. Indeed, referring toFIG. 4C, a portion of outsole522adjacent flange540 may create astop surface534 forming part of recessedarea531, and a portion of stop surface546 of outsole522 may act as astop surface534 for recessedarea532, as shown. As such, once outsole522 is attached to shell520, any of theaforementioned chassis50,150,350 may be inserted into and secured withinshell520 in the manner described previously. In other embodiments, it is also contemplated that the size ofopening538 and the configuration of outsole522 may be modified, if desired.
• Yet an additional variant of footwear is shown inFIGS. 5A-B. In this variant, as with the others, like reference numerals refer to like elements unless otherwise indicated (although in the 600-series instead of, as an example, the 10-series).
• Referring toFIG. 5A, analternate shell620 is shown.Shell620 may be made of any of the materials and according to any of the processes as set forth above forshells20,120,320,520.Shell620 includes aninternal cavity621, an upper624, anoutsole622, and heel626,forefoot628, andinstep630 sections, as withshells20,120,320,520.Shell620 differs fromshells20,120,320,520, however, in that it has a different arrangement for engaging with itscorresponding chassis650, shown inFIG. 5B. Indeed,shell620 includes a set ofrecesses606,607 for engaging with certain sections of chassis650 (described in more detail below) to retainchassis650 withinshell620.Recesses606,607, in a preferred embodiment, extend substantially entirely or entirely around the perimeter ofshell620, as shown inFIGS. 5A-B, although it is contemplated thatrecesses606,607 may alternatively be formed along only certain sections of the perimeter ofshell620 and not along other sections. In one embodiment,recess606 may be stepped to engage with a correspondingly-shaped section ofchassis650.
• Chassis650 is shown inFIG. 5B (and represented in outline inFIG. 5A).Chassis650 includes achassis body601 and, in some cases, anoptional puncture device605 overlying a section ofchassis body601.Puncture device605 may protect a user's foot from damage due to a sharp object puncturing throughchassis body601, and thus,puncture device605 is constructed of a rigid material adapted to block the object from puncturing throughdevice605 and injuring the user's foot.Chassis650 also includes an optional safety toe652 (not shown). Althoughsafety toe652 is not actually shown in the figures, it is represented by a cavity in the area ofchassis650 wheresafety toe652 would be located. In one embodiment,safety toe652 may be press-fit, adhered, or otherwise secured within that cavity ofchassis650, if desired, so thatchassis650 includes asafety toe652 for protection.Safety toe652, as with the previous toe caps52,152,352, may be formed of rigid material, such as a hard polymer, metal, or other material, and include a section overlying a user's toes to protect the toes from injury (e.g., due to a heavy object falling on the user's toe area).
• In one embodiment,chassis body601 also includes specific geometries for engaging withshell620. For instance,chassis body601 includes a set offlanges602 for engaging withrecesses606,607 inshell620, and a set of projections603 for receivingoptional puncture device605 and/or contacting a section of recess606 (e.g., in the case of the right-side projection603 inFIG. 5B).Flanges602 may be formed entirely or substantially entirely around the perimeter ofchassis650, as shown inFIGS. 5A-B, so that, once engaged,chassis650 is not removable from shell620 (e.g., during ordinary use by the user). In alternate embodiments,flanges602 are formed only along certain sections of the perimeter ofchassis650, but not along other sections.Chassis body601 also includes a stop surface/end604 for engaging with a separate stop surface634 ofshell620.
• To insertchassis650 withinshell620 so that the combined unit is usable as footwear,shell620 may first be produced according to the methods discussed above and allowed to expand to its final state (e.g., by using expandable EVA materials inserted into a mold). Then,chassis650 may be inserted intocavity621 ofshell620, such that itsflanges602 are arranged withinrecesses606,607, as shown in outline inFIG. 5A. This acts to at least partially retainchassis650 withinshell620, such thatchassis650 cannot be removed by a user. In other words, sinceflanges602 are engaged withrecesses606,607 about substantially or the entire perimeter ofchassis650 andshell620, as shown in outline inFIG. 5A,chassis650 is securely retained withinshell620.
• During insertion ofchassis650 intoshell620, stop/end surface604 ofchassis650 may also come to rest on stop surface634 ofshell620 to assist in securingchassis650 relative to shell620. In one embodiment, a step is also formed inchassis body601 and shell620adjacent instep region630 for even further enhanced engagement betweenchassis650 and shell620 at that area. Withchassis650 secured inshell620, for example through press-fitting, adhering, cementing, or otherwise securingchassis650 intoshell620, as described in more detail with reference to the previous embodiments, the user may utilize the footwear of this embodiment in applicable industrial or other environments and obtain adequate protection.
• In the devices depicted in the figures, particular structures are shown that are adapted for use in footwear, such devices serving to protect the foot of a user and provide compliance with certain safety standards. The use of alternative structures for such purposes, including structures having different lengths, shapes, and configurations is also contemplated. As an example, while the disclosed footwear is described above in connection with use in the drilling industry, such footwear is equally usable in other industries in which corrosive environments and/or safety hazards are encountered. For instance, the footwear may be equally usable in the context of the hazmat, food processing, environmental clean-up, or other such industries. Put simply, the footwear has applicability in any area in which the working environment includes the presence of corrosive materials and/or safety dangers.
• As another example, it is contemplated that stop surfaces34,134,334,534,634 ofrespective shells20,120,320,520,620 may be angled in certain embodiments to better retainchassis50,150,350,650; and that, if necessary, the respective stop surfaces ofchassis50,150,350,650 that engage stop surfaces34,134,334,534,634 ofshells20,120,320,520,620 may be angled as well. In other words, in one embodiment, stop surfaces34,134,334,534,634 ofrespective shells20,120,320,520,620 may be arranged so that an acute angle is formed at the junction of the inner surface ofshells20,120,320,520,620 and therelevant stop surface24,134,334,534,634. In this manner, the respective component ofchassis50,150,350,650 (e.g.,toe cap52,152,352,652,heel counter86,186,386, and/or metatarsal guard198) may be more securely retained withinshell20,120,320,520,620 via the interaction between the stop surface(s) of those components, and the angled stop surfaces34,134,334,534,634 ofshells20,120,320,520,620. Of course, in some cases several of stop surfaces34,134,334,534,634 ofshells20,120,320,520,620 may be arranged at an acute angle while others are arranged as shown in the figures and described above. Thus, varying combinations are possible. It is also the case that the stop surface(s) on certain components ofchassis50,150,350,650 (e.g.,toe cap52,152,352,652,heel counter86,186,386, and/or metatarsal guard198) may be angled as well to mate with the acute angle of stop surfaces34,134,334,534,634.
• As yet another example, whilemetatarsal guard198 is not shown in connection withchassis350 ofFIG. 3B, it is contemplated thatguard198 may be situated onchassis350 in much the same manner aschassis150. Thus, certain components from one ofchassis50,150,350,650 may be substituted or added to another ofchassis50,150,350,650, although not depicted in the figures.
• Further, it is also contemplated that the various components ofchassis50,150,350,650 may be arranged differently than shown in the figures. For example, while puncture-resistant insole410 is shown as being attached toinner surfaces354,388 oftoe cap352 andheel counter386, respectively,insole410 may be arranged tooverlay toe cap352 and heel counter386 (e.g., be attached toouter surfaces356,390 thereof). In such an embodiment, shell320 (in particular recessedareas331,332) may also be reconfigured so thatchassis350 is securely retained withinshell320. Thus, a number of different configurations are contemplated in which thevarious chassis50,150,350,650 may be rearranged and accommodated, securely, within one ofshells20,120,320,520,620.
• As yet another example, it is contemplated that any ofchassis50,150,350,650 may be composed of expandable materials (likeshells20,120,320,520,620) so that, once inserted intoshell20,120,320,520,620, thechassis50,150,350,650 may expand and be more securely retained within recessedareas31,32,131,132,331,332,531,532. The expandable materials that could be utilized to composechassis50,150,350,650 are set forth above.
• It is also the case thatshells20,120,320,520,620, while described above as being formed via the use of expandable materials, may alternatively be formed with non-expandable materials (e.g., traditional rubber materials, other composites, etc.) In short, the concepts of the present invention(s) have applicability withnon-expandable shells20,120,320,520,620 in thatsuch shells20,120,320,520,620 may receive any ofchassis50,150,350,650 securely therein to adequately comply with the aforementioned safety standards. Thechassis50,150,350,650, once inserted within theparticular shell20,120,320,520,620, however, would likely be non-removable fromsuch shell20,120,320,520,620 to meet those standards.
• Although aspects of the invention(s) herein have been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of aspects of the present invention(s). It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention(s) as set forth in the appended claims.
• It will also be appreciated that the various dependent claims and the features set forth therein can be combined in different ways than presented in the initial claims. It will also be appreciated that the features described in connection with individual embodiments may be shared with others of the described embodiments.

Claims (12)

1. A method of constructing footwear comprising:

providing a mold having an inner cavity;

injecting an expandable material into the inner cavity;

removing the expandable material from the inner cavity, such that the material expands to form a footwear-shaped shell, the shell having an inner cavity and at least one recessed area offset from an inner surface of the shell; and

inserting a chassis within the inner cavity of the expanded shell, the chassis having one or more components adapted to protect a user's foot from injury, wherein insertion of the chassis within the shell permanently affixes the one or more components within the at least one recessed area of the shell.

2. The method according toclaim 1, wherein inserting the chassis within the inner cavity of the shell comprises positioning a stop surface of the one or more components so that it interferes with a stop surface arranged adjacent the at least one recessed area.

3. The method according toclaim 2, wherein interference between the stop surfaces secures the one or more components within the at least one recessed area.

4. The method according toclaim 1, further comprising adhering the one or more components of the chassis to the at least one recessed area.

5. The method according toclaim 1, wherein the shell is composed of a corrosive-resistant material, or a material selected from the group consisting of a polyolefin elastomer, ethyl vinyl acetate, an expandable polymer, or a co-polymerized material suitable for cross-link foaming in a post-injection expandable foaming process.

6. The method according toclaim 1, wherein the shell is impermeable to water or other solutions.

7. The method according toclaim 1, wherein the chassis includes a toe cap composed of rigid material, a heel counter, and an insole board engaged to the top cap and heel counter, and wherein the one or more components comprise the toe cap and heel counter.

8. The method according toclaim 7, wherein the chassis includes a metatarsal guard adapted to be positioned over a user's metatarsal region to protect the user's metatarsal region from injury.

9. The method according toclaim 7, wherein the chassis includes a puncture-resistant insole engaged to the toe cap and heel counter.

10. The method according toclaim 3, wherein the stop surface adjacent the at least one recessed area is at an acute angle to the inner surface of the shell.

11. The method according toclaim 1, wherein each recessed area includes a set of stop surfaces arranged at an angle to the inner surface of the shell, and each component includes corresponding stop surfaces adapted to engage with the stop surfaces of the shell to retain the component within the recessed area.

12. The footwear system according to methodclaim 1, wherein the chassis is expandable from a first dimension to a second greater dimension to permanently lock the chassis in place within the shell.

Images