DETAILED DESCRIPTION OF THE INVENTION

[0036] Referring to FIG. 1, one embodiment of footwear (i.e., a shoe) comprising sole 2 and upper 3 connected to sole 2 is identified by the number 1. Sole 2 comprises opaque outsole 4; midsole 5; and an insole (not visible in FIG. 1). In other embodiments, sole 2 may comprise an outsole and a midsole, the outsole being provided to contact a surface, while the midsole directly contacts a wearer's foot, so that no insole is present. While a left-foot shoe is depicted in FIG. 1, it is to be understood that similar elements, differing in enantiomeric configuration, are also present in embodiments of a right-foot shoe. It is to be understood that all elements of the present invention may apply to embodiments of either right-foot or left-foot footwear.

[0037] Referring to FIGS. 1 and 2, midsole 5 comprises toe-to-heel midsole section 10, which is made entirely of clear (i.e., translucent or transparent) material. Sidewalls extending upward from opaque outsole 4 cover some of the side areas of midsole section 10 along the front region and, partially, heel region of sole 2, blocking through these side areas visibility of cushioning cassettes 44 and 53 in the cavities of midsole section 10. However, in this particular embodiment, opening 6 in outsole 4 provides visibility of cushioning cassette 44 in the front-region cavity, while opening 7 provides visibility of cushioning cassette 53 in the heel-region cavity, through lower clear surfaces of toe-to-heel midsole section 10.

[0038] Referring to FIG. 2, a front-region cavity (between open cells 8 and 9) holding two-chambered cushioning cassette 44 (having inner chamber 11 and outer chamber 12) and a heel-region cavity (between open cells 13 and 14) holding thicker cushioning cassette 53 (having inner chamber 15 and outer chamber 16) are each formed by interior side walls of a periphery of open cells in midsole section 10. The front-region cavity is accessible by lifting insole area 17 to permit removal and replacement of cushioning cassette 44, while the heel-region cavity is accessible by lifting insole area 18 to permit removal and replacement of thicker cushioning cassette 53. In either case, the lifting of sock liner 19 occurs with the lifting of insole areas 17 or 18. When within a cavity, each cushioning cassette is visible through clear material of the sides of midsole section 10, as well as through the lower clear surfaces of toe-to-heel midsole section 10 above openings 6 and 7 in outsole 4.

[0039] In other embodiments of the insole, insole areas 17 and 18, over cushioning cassettes 44 and 53, respectively, may be free of attachment to other areas of the insole. That is, insole area 17 and insole area 18 may simply be separate pads over cushioning cassette 44 and cushioning cassette 53, respectively. However, in such embodiments of the insole, insole area 17 and insole area 18 may be attached to the lower surface of sock liner 19, so that the lifting of sock liner 19 again occurs with the lifting of insole areas 17 or 18.

[0040] Referring to FIG. 3, a toe-to-heel midsole section for a right-foot shoe is identified by the number 20. Toe-to-heel midsole section 20 is like toe-to-heel midsole section 10 of FIGS. 1 and 2 except for being of a right-foot shoe rather than a left-foot shoe. Other views of toe-to-heel midsole section 20 are depicted in FIGS. 4 and 5. Toe-to-heel midsole sections 10 (of FIGS. 1 and 2) and 20 (of FIGS. 3-5) are made of a clear elastomeric material (as are front midsole section 40 of FIGS. 6-8 and heel midsole sections 50 of FIGS. 10-13, 70 of FIGS. 16-17, 80 of FIG. 18, and 90 of FIGS. 19-20). The clear material may be transparent, or translucent, though, in either case, the color of a cushioning cassette is visible through the clear material of a sole when viewed from outside of the footwear.

[0041] The clear material, which can be based on either thermoplastic or thermosetting resin systems, can be formulated from any elastomeric material that can be made into a clear product with a combination of sufficient strength, flexibility, and durability. As noted in EP Publication No. 0 456 434 A2 (incorporated herein by reference), thermosetting systems are generally preferred because of compatibility of processing techniques and better physical properties. As also noted in EP Publication No. 0 456 434 A2, suitable elastomeric materials include synthetic elastomers based on homo and copolymer systems such as polycondensation polymers (e.g., polyurethanes), ethylene-propylene based copolymers (e.g., EPDM), other synthetic rubber materials (e.g., SBR, neoprene, etc.), vinyl-based polymers (e.g., polyvinyl chloride), polyacrylate copolymers, and the like.

[0042] Referring to FIGS. 3 and 5, cavity 22 is formed in the front region of toe-to-heel midsole section 20 by interior side walls of a periphery of open cells, like open cells 23, 24, 25, and 26. An open cell—like any one of cells 23, 24, 25, and 26—has no ceiling that joins with side walls to form a closed cell.

[0043] Referring again to FIG. 3, interior side walls of open cells form cavity 22 having a shape that is approximately that of an equatorially-squeezed marshmallow section for receiving cushioning cassette 44 of (FIGS. 1, 2, 6, 7, and 9). In other embodiments of the present invention, the shape of cavity 22 could greatly vary.

[0044] The bottom of cavity 22 is lined with shorter reticulated wall structure for supporting cushioning cassette 44. In other embodiments, the shorter reticulated wall structure could be in a honeycomb-like arrangement of open cells, each having a largely uniform size. In other embodiments, the reticulated wall structures could be webbed in other dimensions. Walls of open cell 27, which typify walls on cavity 22's bottom, are less than about one-third the height of walls like those of open cells 23, 24, 25, or 26 in this particular embodiment of toe-to-heel midsole section 20. In other embodiments, heights of walls of open cells like cells 23, 24, 25, or 26 could vary considerably in comparison to each other and to walls on cavity 22's bottom. Furthermore, in other embodiments, the cells could be closed, the walls of cells (closed or open) could be reticulated in other dimensions, or the walls of cells could be arranged in a honeycomblike pattern wherein the cells are each of a largely uniform size.

[0045] Referring again to FIGS. 3 and 5, cavity 28 is formed in the heel region of toe-to-heel midsole section 20 by interior side walls of a periphery of open cells, like open cells 29, 30, 31 and 32. Walls of open cells—like open cells 29, 30, 31, and 32—form cavity 28 to be approximately oval in shape, having a diameter between the interior side walls of open cells 29 and 30 that is about one-and-a-half times the diameter between the interior side walls of open cells 31 and 32 in this particular embodiment. In other embodiments of the present invention, the ratio of diameters could greatly differ, as could the shape of the cavity.

[0046] With the interior side walls of the open cells that form heel-region cavity 28 being higher than those that form front-region cavity 22, the cushioning cassette (53 of FIG. 14) that fits within heel-region cavity 28 differs from the cushioning cassette (44 of FIG. 9) that fits within front-region cavity 22 not only in being approximately oval in shape (rather than being shaped as an equatorially-squeezed marshmallow section), but also in being about twice as high or thick, in this particular embodiment.

[0047] Cavity 28, like cavity 22, has a bottom that also comprises reticulated wall structure for supporting a cushioning cassette. Walls of open cell 33 on the bottom of cavity 28 are about the same height as walls of open cell 27 on the bottom of cavity 22. For either cavity 22 or cavity 28, the shorter wall height contributes to causing cushioning cassettes, which are typically not as high or thick as the side walls that form each cavity, to protrude above the plane of the top surface of toe-to-heel midsole section 20 in this particular embodiment. Other embodiments of midsole sections—including other toe-to-heel midsole sections, as well as front midsole sections and heel midsole sections—may contain longer or shorter walls, or no walls at all, to cover a cavity's bottom.

[0048] Referring to FIG. 4, molded upward extensions, like upward extension 34, provide surfaces for attaching toe-to-heel midsole section 20 to shoe uppers (like left-foot shoe upper 3 of shoe 1 in FIG. 1, except for a right-foot shoe). In FIG. 4, dashes or hidden lines 35 along the outsole-adjacent boundary of toe-to-heel midsole section 20 outline height maximums for interiorly-oriented impressions on the lower surface of midsole section 20.

[0049] Referring to FIG. 5, toe-to-heel midsole section 20 is made largely of clear material in this particular embodiment. Areas of potential attachment by an outsole on the lower surface of toe-to-heel midsole section 20 may be marked by swellings or molded discontinuities (not visible in FIG. 5). Similar swellings or molded discontinuities may also be found near the lower surfaces of other embodiments of midsoles sections (e.g., front midsole sections of FIGS. 6-8 or heel midsole sections of FIGS. 10-13 and 16-20). Hidden lines outline where, on the opposite side of toe-to-heel midsole section 20, cavities 22 and 28 are located.

[0050] Referring to FIG. 6, a front midsole section for a left-foot shoe is identified by the number 40. Interior side walls of open cells, like open cells 47 and 48, form a cavity, approximately the shape of an equatorially-squeezed marshmallow section, for cushioning cassette 44, which is in place. Cushioning cassette 44 may fit snugly within the cavity of either a right-foot or left-foot front midsole section, though the bottom side of cassette 44 in a cavity of a front midsole section for a right-foot shoe becomes the top side of cassette 44 in a cavity of a front midsole section for a left-foot shoe, and visa versa. In this particular embodiment, except for sidedness, the dimensions of the cavity are approximately the same as the dimensions of cavity 22 of toe-to-heel midsole section 20 of FIG. 3. In this particular embodiment, front midsole section 40 is made entirely of clear material, so that cushioning cassette 44 is visible through both the sides and the lower surface of front midsole section 40.

[0051] Referring to FIG. 7, a side view of a cross-section of the front midsole section of FIG. 6 is again identified by the number 40. Molded upward extensions, like upward extension 42, provide surfaces for attaching front midsole section 40 to shoe uppers. Cushioning cassette 44 is in the cavity of front midsole section 40. Walls of open cells in front midsole section 40 are also depicted. In this particular embodiment, shorter walls, like walls 45 and 46 of open cells beneath cushioning cassette 44 on the cavity's bottom have a height similar to, referring again to FIG. 3, the height of the walls of open cell 27 on the bottom of cavity 22. In other embodiments, the height of cell walls on the bottom of cavities may differ markedly. As noted previously for walls of cells on the bottom of cavities for cushioning cassettes, in other embodiments of front midsole sections, longer or shorter walls, or no walls at all, may be found on a cavity's bottom.

[0052] Referring to FIG. 8, a front view of a front midsole section for a left-foot shoe is again identified by the number 40. Molded upward extensions, like upward extension 41, provide surfaces for attaching shoe uppers to front midsole section 40. Hidden lines along the lower surface indicate the position of walls of open cells on the upper or cell-containing side of front midsole section 40. A cushioning cassette is not present in a cavity of front midsole section 40 in the particular view presented in FIG. 8.

[0053] Referring to FIG. 9, one embodiment of a cushioning cassette is identified by the number 44. Referring also to FIGS. 3 and 5, front-region cavity 22 of left-foot, toe-to-heel midsole section 20 receives, in a snug fit, cushioning cassette 44. Referring also to FIGS. 6 and 7, the cavity of left-foot front midsole section 40 also receives, in a snug fit, cushioning cassette 44. Again, cushioning cassette 44 may fit snugly within the cavity of either a right-foot or left-foot midsole section, though the bottom side of cassette 44 in a cavity of a midsole section for a right-foot shoe becomes the top side of cassette 44 in a cavity of a midsole section for a left-foot shoe, and visa versa.

[0054] Referring again to FIG. 9, exteriors of inner chamber 11 and outer chamber 12 (of FIGS. 2 and 7) are demarcated by groove 47 in this particular embodiment of cushioning cassette 44. In other embodiments, cushioning cassette 44 may have but one chamber, or comprise two or more chambers. In brief, in other embodiments the shape and chamber configuration of cushioning cassette 44 may vary greatly. Material of which cushioning cassette 44 is preferably made, as well as the containment of a gaseous medium within cushioning cassette 44, is as described later for cushioning cassette 53 (of FIGS. 10-12, 14, and 15)

[0055] Referring to FIG. 10, one embodiment of a heel midsole section, from a top view, is identified by the number 50. Other views of heel midsole section 50 are depicted in FIGS. 11-13; they are also identified by the number 50.

[0056] Referring to FIGS. 10-13, cavity 52 is formed in heel midsole section 50 by interior side walls of a periphery of closed cells, like closed cells 54, 55, and 56. These cells are designated closed because a ceiling closes the cells. Interior side walls of a periphery of these closed cells form cavity 52, in which cushioning cassette 53 snugly fits, to be roughly oval in shape. In this particular embodiment, the dimensions of cavity 52 are approximately the same as the dimensions of heel-region cavity 28 of toe-to-heel midsole section 20 of FIG. 3.

[0057] As a ceiling wall forms cells 54, 55, and 56 to be closed cells, a ceiling wall may form, in other embodiments, cells of front midsole sections, like section 40 of FIGS. 6-8, as well as cells of toe-to-heel midsole sections, like section 20 of FIG. 3, also to be closed cells Referring to FIG. 13, shorter walls, like walls 58 and 59 of open cells on the bottom of cavity 50, are similar in height in this particular embodiment to walls 45 and 46 beneath cushioning cassette 44 of FIG. 7, as well as to walls of open cell 33 on the bottom of cavity 28 of FIG. 3. As noted previously for other midsole sections, these walls on the bottom of the cavity of a heel midsole section may be absent or vary greatly in height. In other embodiments of heel midsole sections, as well as of front midsole sections and toe-to-heel midsole sections, a ceiling wall may also form cells on a cavity's bottom to be closed cells.

[0058] Referring to FIGS. 1-13, all cell walls—i.e., side, bottom, and ceiling walls of closed cells, or, side and bottom walls of open cells, whether outside or within a cavity—in midsole sections are of a similar thickness in these particular embodiments. In other embodiments of the present invention, however, the thickness of all walls may vary greatly within, as well as between, embodiments. For example, the ceiling wall that forms closed cells of cells of heel midsole section 50 (such as closed cells 54, 55, and 56) may be approximately one-fifth as thick as the side and bottom walls of heel midsole section 50 in a preferred embodiment.

[0059] Referring to FIGS. 14 and 15, one embodiment of a cushioning cassette is identified by the number 53. Referring also to FIGS. 1-3, 10-12, cushioning cassette 53 is sized to fit snugly within heel-region cavity 28 of toe-to-heel midsole section 20 (of FIG. 3) (or as shown in FIGS. 1 and 2 for toe-to-heel midsole section 10) or within cavity 52 of heel midsole section 50 (as shown in FIGS. 10-12). Cushioning cassette 53 also has outer and inner chambers. In a preferred embodiment, oval torus-shaped outer chamber 16 surrounds stretched pillow-shaped inner chamber 15 (shown in FIGS. 2 and 15). In this particular embodiment, elastomeric material joins the outer walls of the two chambers so as either to allow, or not to allow, sharing of gaseous medium between the chambers through a passageway. In preferred embodiments, the same elastomeric material that joins the two chambers also forms the walls of the chambers. Whether sharing of gaseous medium between chambers is allowed or not allowed, the gaseous medium is held in sealed containment within the cassette if elastomeric material prevents escape of gaseous medium.

[0060] The elastomeric material of which cushioning cassette 53 is preferrably made is a thermoplastic elastomer, such as thermoplastic polyurethane (TPU). The elastomeric material may also be of the following materials, without being limited thereto: adduct rubber, butadiene acrylonitrile rubber, butadiene styrene rubber, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene propylene polymer, fluoroelastomer, high-strength silicone rubber, low-density polyethylene, methyl rubber, natural rubber, neoprene, polyester elastomer, polyether polyurethane, polyethylene/ethylene vinyl acetate copolymer, polyurethane, polyvinyl chloride, sulfide rubber, thermoplastic rubbers, and the like (see U.S. Pat. Nos. 4,817,304 and 5,685,090, each incorporated herein by reference, as well as EP Publication No. 0 456 434 A2, previously incorporated herein by reference).

[0061] Referring to FIG. 15, the gaseous medium that fills chambers 15 and 16 preferably comprises clean ambient air, or, more preferably, one or more elements of clean ambient air having lower oxidizing potentials, such as argon. The gaseous medium that fills chambers of cushioning cassettes for a front-region cavity (such as chambers 11 and 12 of cushioning cassette 44 of FIG. 9) also preferably comprises clean ambient air, or, more preferably, one or more elements of clean ambient air having lower oxidizing potentials, such as argon.

[0062] By way of example, and not limitation, ambient air for a typical terrestrial location is, by volume, approximately 21% oxygen, 77% nitrogen, 1% argon, and 0.3% carbon dioxide, with 0.97% a mixture of other gases like hydrogen, neon, krypton, helium, ozone, and xenon. The filling of a chamber with ambient air as the gaseous medium, does not require that the ambient air be sealed within the chamber for the cassette to provide cushioning, though sealed containment of ambient air within cushioning cassette 53, or cushioning cassette 44, is preferred, whether or not the contained gaseous medium may exchange between chambers 15 and 16 of cassette 53 (of FIGS. 2 and 15) or chambers 11 and 12 of cassette 44 (of FIGS. 2 and 7). If the elastomeric material of which a cassette is made has a sufficient hysteresis capacity (i.e., a capacity repeatedly to return quickly to an original molded shape despite being repetitively struck or depressed), ambient air (or other gaseous medium) within a cushioning cassette need not be in sealed containment. In other words, if the hysteresis capacity of a cushioning cassette's elastomeric material itself provides sufficient cushioning capacity, requiring that ambient air (or other gaseous medium) be in sealed containment in the elastomeric material of a cushioning cassette may not be necessary.

[0063] Referring to FIGS. 11 and 12, while cushioning cassette 53 is shown as being significantly higher than the top of the side wall of the cavity that it occupies, the heights of cushioning cassettes in other embodiments may vary from being near the tops of the side walls (as for cushioning cassette 44 in FIGS. 2 and 7) to being even further above the tops of the side walls than cushioning cassette 53 is in FIGS. 11 and 12. Furthermore, cushioning cassettes of other embodiments may be single-chambered or comprise more than two chambers. In addition, the thickness of chamber walls may vary from being as thin as soap film to being thicker than midsole section walls, for example, thicker than the walls within heel midsole section 50.

[0064] In addition to ambient air, other gases, without limitation, that may be used to fill chambers of cushioning cassettes (such as cassettes 44 and 53) in a sealed manner include halogenated alkanes and alkenes such as: bromotrifluoromethane, chlorofluoroethylene, 1,2-dichlorotetrafluoroethane, hexafluoroethane, hexafluoropropylene, monochloropentafluoroethane, monochlorotrifluoromethane, octafluorocyclobutane, perfluorbutane, perfluorocyclobutane, perfluorohexane, perfluoroheptane, perfluoropropane, tetrafluoromethane, 1,1,2-trichloro-1,2,2-trifluoroethane, and the like, as well as other gases, including sulfur hexafluoride (see U.S. Pat. No. 4,817,304 and EP Publication No. 0 456 434 A2, each previously incorporated herein by reference).

[0065] Referring to FIGS. 2, 7, 9, 14, and 15, in a preferred embodiment, chambers of cushioning cassettes (such as chambers 11 and 12 of cushioning cassette 44, and chambers 15 and 16 of cushioning cassette 53) are each filled during manufacture with clean ambient air to a fixed pressure level. In this preferred embodiment, cushioning cassette 53 contains no valve or other mechanical component to adjust the pressure of the gaseous medium of ambient air within each chamber, though pressure within each chamber may be variously set on manufacture of the cushioning cassette. Since clean ambient air is used to fill each chamber in this particular preferred embodiment, release of potentially environmentally damaging gases, such as chlorofluorocarbons (CFCs), is avoided.

[0066] Referring to FIGS. 16-20, embodiments of the present invention are depicted wherein column-like cushioning cassettes—such as cassettes 71 (of FIG. 17) or 81 (of FIG. 18)—or box-like cushioning cassettes—such as cassette 91 (of FIG. 20)—may be removed and replaced through a lateral or medial side of a heel midsole section, such as a heel midsole sections 70 (of FIGS. 16 and 17), 80 (of FIG. 18), or 90 (of FIGS. 19 and 20). In these particular embodiments, the side-inserted cushioning cassettes are single-chambered and also are preferably filled with one or more elements of clean ambient clean air. Like cushioning cassettes described earlier, side-inserted cushioning cassettes in other embodiments may have two or more chambers. In addition, other embodiments of side-inserted cushioning may be filled in a sealed manner with a gaseous medium comprising a halogenated alkane, a halogenated alkene, or sulfur hexafluoride.

[0067] Referring to FIG. 16, column-like cushioning cassette 71 is within cavity 77 of heel midsole section 70. Side walls of closed cells, like cells 74 and 75, form cavity 77 and side walls of other closed cells, like cells 75 and 76, form cavity 78 of heel midsole section 70.

[0068] Referring to FIG. 17, side walls of closed cells—like cells 74, 75, and 76—of heel midsole section 70 form cavities 77 and 78 for receiving side-inserted, column-like cushioning cassettes 71. Since side walls of closed cells, like cells 74 and 75, form cavity 77, and side walls of other closed cells, like cells 75 and 76, form cavity 78 of heel midsole section 70, it can be said of these embodiments that interior walls of a periphery of cells form in midsole section 70 at least one cavity for receiving side-inserted cushioning cassette 71.

[0069] Referring to FIG. 18, side-inserted, column-like cushioning cassettes contain notches 82 to hold the cassettes to mating, notch-receiving indentations 83 in heel midsole section 80. Side walls of open cells—like cells 84, 85, and 86—of heel midsole section 80 form cavities 87 and 88 for receiving side-inserted, column-like cushioning cassettes 81.

[0070] Referring to FIGS. 19 and 20, side-inserted, box-like cushioning cassette 91 contains indentations 92 to receive inward-oriented notches 93 of the cavity of heel midsole section 90. Again, since interior side walls of closed cells, like cells 94 and 95, form in midsole section 90 at least one cavity for receiving side-inserted cushioning cassette 91, it can be said of these embodiments that interior walls of a periphery of cells form in midsole section 90 at least one cavity for receiving side-inserted, box-like cushioning cassette 91.

[0071] Referring again to FIG. 2, a method for modifying a color pattern of shoe 1 comprises lifting insole area 18 (sock liner 19 being lifted with insole area 18), removing cushioning cassette 53 from the cavity of the heel region of toe-to-heel midsole section 10 of shoe 1, and replacing removed cassette 53 with another of a different color. Another method for modifying a color pattern of shoe 1 comprises lifting insole area 17 (sock liner 19 being lifted with insole area 17), removing cushioning cassette 44 from the cavity of the front region of toe-to-heel midsole section 10 of shoe 1, and replacing removed cassette 44 with another of a different color.

[0072] Referring again to FIG. 2, a method for modifying impact response capacity of shoe 1 comprises lifting insole area 18 (sock liner 19 being lifted with insole area 18), removing cushioning cassette 53 from the cavity of the heel region of toe-to-heel midsole section 10 of shoe 1, and replacing removed cassette 53 with another having a different cushioning capacity. Another method for modifying impact response capacity of shoe 1 comprises lifting insole area 17 (sock liner 19 being lifted with insole area 17), removing cushioning cassette 44 from the cavity of the front region of toe-to-heel midsole section 10 of shoe 1, and replacing removed cassette 44 with another having a different cushioning capacity.

[0073] Similar methods (for modifying a color pattern or for modifying impact response capacity of footwear), but not including the lifting of an insole area, may be used for embodiments either lacking an insole, or having cassettes in cavities that are accessible without lifting an insole (for example, a cavity amenable to receiving cassettes inserted from a sole side, as in the heel midsole sections of FIGS. 16-20, or a front or a toe-to-heel midsole section having a cavity for a side-inserted cassette in front or heel regions). In embodiments lacking an insole, but having a sock liner, the removing of a cassette from a cavity accessible through an opening under the sock liner also lifts the sock liner so that a cassette (of a different color or a different cushioning capacity) may be placed in the cavity.

[0074] With embodiments of the present invention, an article of footwear, and particularly an athletic or sport shoe, may be tailored to display a particular color pattern. In addition, the footwear may be tailored to have an appropriate impact response capacity. Both a particular color pattern and an impact response capacity may be optimized for activities of the wearer of the footwear.

[0075] It is also to be understood that the visible, replaceable cushioning cassette apparatus of the present invention may be utilized in other articles of manufacture wherein it is desired to alter the cushioning or pressure resistance of the article or change the color or color pattern of the article. Accordingly, the visible, replaceable cushioning cassette, as provided by the present invention, may be utilized, without limitation, in grips and gripping elements of all kinds (including, for example, handles for suitcases or levers for furniture and appliances), pads or padding elements of all kinds (including, for example, bottom units for feet of chairs, stools, or stands; or seat units for furniture, buses, or airplanes), cushioning components of all kinds (including, for example, packaging pads and automotive or aerospace cushioning devices), and the like.

[0076] While footwear of the present invention, i.e., footwear having a sole with a visible, replaceable cushioning cassette, has been described in connection with preferred embodiments, the invention is not intended to be limited to the particular embodiments described. On the contrary, the invention is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.