Patent Publication Number: US-6339888-B1

Title: Disposable shoe cover

Description:
The present application is a Continuation application of Ser. No. 09/069,299 filed on Apr. 29, 1998, now U.S. Pat. No. 6,023,856. 
     This application is a Continuation-in-Part (CIP) application of U.S. patent application Ser. No. 08/686,348, filed Jul. 25, 1996 now abandoned. 
     This invention is related in general to disposable protective clothing and in particular to disposable shoe covers. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     Background of the Invention 
     Sterile reusable clothing has previously been used in many health care environments. Due to the inconvenience and cost of cleaning and providing sterile storage for such clothing, a switch to disposable products has generally occurred. For example, the demand for disposable shoe covers has increased substantially during the past several years and is now standard practice for most surgical procedures. Health care workers in emergency rooms and other medical environments wear disposable shoe covers to protect the health care environment from microbial and other types of contamination carried by shoes and to protect the respective health care worker from contamination by blood and other body fluids. 
     In addition to the health care industry, it is necessary in many other industries to wear protective clothing to prevent contamination of clean room type working environments. In certain environments it is also necessary to prevent stray electricity such as static electricity and sparks, from damaging sensitive electronic circuits or accidentally igniting a possibly volatile atmosphere. 
     Disposable shoe covers are worn in a wide variety of industrial environments for many reasons such as providing either a conductive or non-conductive electrical surface depending upon the environment preventing contamination of both the wearer and the surrounding environment, and providing a non-skid walking surface for the wearer. Disposable shoe covers have often been manufactured from a single type of material. Since it is difficult to find a single material with all the desired characteristics such as, fluid resistance, breathability, non-skid surface, anti-static and durability, some desired characteristics have frequently been enhanced to the detriment of other desired characteristics. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a disposable shoe cover is provided to substantially reduce or eliminate shortcomings previously associated with prior disposable shoe covers. A disposable shoe cover incorporating teachings of the present invention provides an effective barrier to protect the surrounding environment from any contamination carried by the wearer&#39;s shoes and at the same time assists with protecting the wearer for the surrounding environment. A disposable shoe cover may be formed from material selected in accordance with the teachings of the present invention to protect the wearer&#39;s shoes and feet from contamination by potentially dangerous fluids, liquids, aerosols and/or other sources of contamination in the surrounding environment. A disposable shoe cover may be formed from material selected in accordance with the teachings of the present invention to provide a non-skid surface for walking and/or a static free, electrically conductive surface. A relatively low cost disposable shoe cover may be formed in accordance with the teachings of the present invention from different types of material to provide all or selected portions of the previously noted features. 
     One aspect of the present invention includes providing a disposable shoe cover formed from a generally quadrilateral sheet of material or blank having three panels. Four resilient or elastomeric bands or strips are disposed on and attached to the quadrilateral sheet of material approximately parallel with and spaced laterally from each other. Two of the elastomeric bands are respectively disposed adjacent to opposite edges of the quadrilateral sheet. The other two elastomeric bands are respectively spaced between the center line of the quadrilateral sheet and one of the elastomeric bands or straps on opposite edges of the quadrilateral sheet. 
     For one application, the quadrilateral sheet of material may be folded along its longitudinal center line. Adjacent lateral edges extending from the resulting fold are preferably sealed to each other to form the disposable shoe cover. For one application a W-shaped fold is preferably formed in the middle panel of the quadrilateral sheet extending along the center line. The W-shaped fold cooperates with sealing the adjacent lateral edges to provide a better fit between the disposable shoe cover and the wearer&#39;s shoe. For still other applications, the quadrilateral sheet may be folded parallel with respect to the middle elastomeric bands to provide a generally T-shaped configuration at each lateral edge of the quadrilateral sheet. The resulting T-shaped configuration at each end of the quadrilateral sheet is preferably sealed to form opposite ends of the resulting disposal shoe cover. 
     Technical advantages of the present invention include high speed manufacture of a relatively low cost disposal shoe cover satisfactory for use with a wide range of shoe types and sizes. The present invention allows selecting appropriate material depending upon the intended working environment to enhance the performance of the resulting disposable shoe cover. For example, materials having high fluid resistance, good breathability, nonskid surface, static free and/or improved wearability may be used as desired to fabricate selected portions of the resulting disposable shoe cover. The present invention allows the use of two or more different types of material without substantially increasing manufacturing costs of the disposable shoe cover other than raw material costs associated with each type of selected material. 
     In accordance with another aspect of the present invention, a disposable show cover may be fabricated from a quadrilateral sheet of material or blank which has been formed from three or more continuous strips or webs of material. For some applications, the three continuous strips may be the same material. For other applications, each continuous strip may be a different type of material to enhance the performance of the resulting disposable shoe cover depending upon the intended working environment. Four bands or straps of elastomeric material are respectfully disposed along each longitudinal edge of the blank and adjacent to each longitudinal junction or seam between the three continuous strips of material. 
     Further technical advantages of the present invention include providing a disposable shoe cover that does not have a seam on the bottom of the shoe cover in contact with the sole of a wearer&#39;s shoe. Particulate contamination is substantially reduced or eliminated by not placing a seam in contact with the sole of a wearer&#39;s shoe. The present invention also results in placing two bands of elastomeric material extending longitudinally along opposite sides of the wearer&#39;s shoe adjacent to the sole. These two elastomeric bands result in shaping a generally rectangular panel in the middle of the blank into a generally oval configuration corresponding approximately with the sole of the wearer&#39;s shoe. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following written description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein: 
     FIG. 1 is a schematic drawing showing a perspective view of a disposable shoe cover incorporating teachings of the present invention on a wearer&#39;s foot; 
     FIG. 2 is a schematic drawing showing an isometric view with portions broken away of equipment used to form an intermediate piece of material for fabrication of disposable show covers in accordance with the teachings of the present invention from three continuous strips or webs of material and four bands or strips of elastomeric material; 
     FIG. 3 is a schematic drawing showing a plan view of a quadrilateral sheet or blank having three panels which may be used to fabricate a disposable shoe cover in accordance with teachings of the present invention; 
     FIG. 4 is a schematic drawing showing a plan view of the blank of FIG. 3 after additional bonded areas have been formed on the elastomeric bands; 
     FIG. 5 is a schematic drawing showing an isometric view of the blank of FIG. 4 folded in accordance with one embodiment of the present invention; 
     FIG. 6 is a schematic drawing showing an isometric view of another step in the process of fabricating a disposable shoe cover from the blank of FIG. 4; 
     FIG. 7 is a schematic drawing showing an isometric view of showing still another step in the process of fabricating a disposable shoe cover from the blank of FIG. 4; 
     FIG. 8 is a schematic drawing showing an isometric view of the blank of FIG. 4 folded in accordance with an alternative embodiment of the present invention; 
     FIG. 9 is a schematic drawing showing another step in the process of fabricating a disposable shoe cover after folding a blank as shown in FIG. 8; 
     FIG. 10 is a schematic drawing showing a plan view of a blank formed with panels of different types of material; 
     FIG. 11 is a schematic drawing showing an isometric view of a blank formed from a single web of material which has been divided into three panels along with an alternative configuration for attaching elastomeric bands to the blank; 
     FIG. 12 is a schematic drawing showing an isometric view of a blank formed from a single web of material which has been divided into three panels along with still another configuration for attaching elastomeric bands to the blank; 
     FIG. 13 is a schematic drawing showing an isometric view of a blank formed from a single web of material which has been divided into three panels along with a further alternative configuration for attaching elastomeric bands to the blank; 
     FIG. 14 is a schematic drawing showing an isometric view of another alternative way of folding a blank to form a disposable shoe cover in accordance with teachings of the present invention; 
     FIG. 15 is a schematic drawing showing an isometric view in the process of fabricating an alternative embodiment of a disposable shoe cover incorporating an angled heel seam section; 
     FIG. 16 is an additional schematic drawing showing an isometric view of an additional step in the process of fabricating the alternative shoe cover illustrated in FIG. 15; 
     FIG. 17 is an additional perspective view of the shoe cover according to the invention illustrated in FIG. 1; 
     FIG. 18 is a perspective view of the shoe covers illustrated in FIGS. 15 and 16 disposed on the foot of a wearer; and 
     FIG. 19 is an additional perspective view of the shoe cover in FIG.  18 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiments of the present invention and its advantages are best understood by referring to FIGS. 1 through 14 of the drawings, like numerals being used for like and corresponding parts of the various drawings. 
     Disposable shoe cover  20  incorporating various teachings of the present invention is shown in FIG. 1 covering shoe  22  on the foot of wearer  24 . As a result of the present invention, disposable shoe cover  20  may be adapted to slip over various types and sizes of shoes and is not limited for use with only shoe  22  shown in FIG.  1 . The present invention may be used to provide disposable covers for boots (not shown) and other types of footwear in addition to shoes. The term “shoe” as used in this application is intended to include all types of shoes, boots, sandals and other types of footwear. 
     A disposable shoe cover may be formed in accordance with teachings of the present invention from a sheet or blank having at least three panels of selected material and four bands or straps of elastomeric material. The terms “band” and “strap” are used in this application to mean a length of material substantially longer than it is wide. The elastomeric bands or straps have a reduced width as compared to the width of the associated panels. 
     Disposable shoe cover  20  is preferably formed from sheet or blank  40  having three panels  41 ,  43  and  45 . Panel  43  or the middle panel of blank  40  is generally disposed under sole  26  of shoe  22 . Panels  41  and  45  are disposed adjacent to and extend over the sides of shoe  22  when disposable shoe cover  20  is placed on the foot of wearer  24 . Panel  41  is not shown in FIG.  1 . 
     For some applications, a disposable shoe cover may be formed in accordance with the teachings of the present invention with more than three panels and four elastomeric bands. However, one of the panels, such as middle panel  43 , is preferably disposed under sole  26  without any seams in direct contact with the bottom of sole  26 . This feature of the present invention substantially reduces particulate contamination from the resulting disposable shoe cover  20 . 
     Blank  40  is preferably folded, bonded and cut in accordance with teachings of the present invention to allow elastomeric bands  87 , 89 ,  91  and  93  to conform disposable shoe cover  20  with various types and sizes of shoes. Disposable shoe cover  20  includes opening  30  defined in part by elastomeric bands  87  and  93  which hold disposable shoe cover  20  on the foot of wearer  24 . Elastomeric bands  89  and  91  are preferably disposed adjacent to and extend longitudinally along opposite sides of sole  26  of shoe  22 . Elastomeric band  89  and  91  cooperate with each other to allow disposable shoe cover  20  to be adopted to a wide variety of shoe sizes and types. Elastomeric bands  87  and  89  are not shown in FIG.  1 . 
     FIG. 2 shows a schematic representation of an apparatus and method which may be satisfactorily used to form disposable shoe cover  20  from three continuous strips or webs of material  81 ,  83  and  85  and four continuous straps of elastomeric material  87 ,  89 , and  91  and  93 . Continuous webs  81 ,  83  and  85  are provided from respective rolls  80 ,  82  and  84  of selected raw material having the desired characteristics for disposable shoe cover  20 . One of the technical benefits of the present invention includes the ability to vary the type of raw material selected to provide each continuous web  81 ,  83  and  85  depending upon the environment in which disposable shoe cover  20  will be worn. Appropriate materials may be selected without substantially increasing the cost of fabricating the resulting disposable shoe cover  20  except for any change in raw material costs. 
     A wide variety of rollers, motors, tensioners, guides and control systems are available to allow quickly replacing rolls  80 ,  82  and  84  such that strips  81 ,  83  and  85  are essentially continuous webs of the selected raw material. In a similar manner, rolls  86 ,  88 ,  90  and  92  may be replaced to provide respectively continuous elastomeric strips  87 ,  89 ,  91  and  93 . 
     U.S. Pat No. 3,684,922 entitled “Anti-Static Plastic Shoe Cover and Method of Making Same”; U.S. Pat. No. 4,304,021 entitled “Method and Apparatus for Making Disposable Shoe Covers”; and U.S. Pat. No. 4,616,429 entitled “Disposable Shoe Cover” show representative examples of various types of rollers, feed motors, tensioners, guides, and control systems that may be satisfactorily used with the present invention. Each of these patents is incorporated by reference for all purposes within this application. 
     Bonding apparatus  100  is provided to attach continuous webs  81 ,  83  and  85  with each other along with elastomeric straps  87 ,  89 ,  91  and  93  to form intermediate piece  102 . Intermediate piece  102  may also be described a continuous web of material having a width equal to approximately the combined total width of continuous webs  81 ,  83  and  85  less any overlap between adjacent portions of continuous webs  81 ,  83  and  85 . 
     For purposes of illustration, elastomeric straps  87 ,  89 ,  91  and  93  are shown attached to tensioner  104  extending from bonding apparatus  100 . In actual practice, tensioner  104  may include a series of tensioners, takeup rollers, clamps and buffers as appropriate for handling a continuous web of material such as intermediate piece  102  and blanks  40  which are formed therefrom. 
     Depending upon the specific type of material associated with continuous webs  81 ,  83 , and  85  and elastomeric straps  87 ,  89 ,  91  and  93 , bonding apparatus  100  may include sewing machines, hot melt adhesive applicators, radio frequency (RF) bonding equipment, ultrasonic bonding equipment, heat and pressure bonding equipment, impulse sealing equipment or any other type of equipment that can be used to attach continuous webs  81 ,  83  and  85  with each other and elastomeric straps  87 ,  89 ,  91  and  93  in accordance with teachings of the present invention. 
     U.S. Pat. No. 5,059,277, entitled “Adhesive-Free Bonding of Continuously Moving Webs to Form Laminate Web”; U.S. Pat. No. 5,114,509, entitled “Starch Adhesive Bonding”; and U.S. Pat. No. 5,383,988, entitled “Modular Apparatus for Fabricating an Absorbent Article” show representative examples of various types of ultrasonic bonding equipment that may be satisfactorily used as part of bonding apparatus  100 . These patents are incorporated by reference for al purposes within this application. The specific type of bonding apparatus may be varied depending upon the material selected for continuous webs  81 ,  83  and  85  and elastomeric straps  87 ,  89 ,  91  and  93 . 
     For the embodiment of the present invention as shown in FIG. 2, middle web or the second continuous web  83  has a width selected to accommodate the width of the sole on a wide variety of shoe sizes and types plus providing sufficient material to form overlapping junctions or longitudinal seams with continuous webs  81  and  85 . The overlapping junction or longitudinal seam between continuous web  81  and  83  is defined in part by a pair of longitudinal bonds  118 . The overlapping junction or longitudinal seam formed between continuous web  83  and continuous web  85  is defined in part by a pair of longitudinal bonds  120 . As best shown in FIG. 3, width  32  of the portion of middle panel  43  between longitudinal edges  119  and  121  corresponds approximately with the maximum width for the sole of a shoe that will fit within the resulting disposable shoe cover  20 . 
     For some applications the width of continuous web or first web  81  and the width of continuous web or third web  85  are selected to be approximately equal to each other and to the width of middle web  83 . For other applications, it may be desirable to have the width of first web  81  and third web  85  substantially larger than the width of middle continuous web  83 . Increasing the width of first webs  81  and third  85  will result in a disposable shoe cover having a greater height to cover more of a wearer&#39;s leg above shoe  22 . Also, additional continuous webs and elastomeric straps may be used to provide a disposable shoe cover having an increased height. For example, a disposable shoe cover (not expressly shown) which extends from the wearer&#39;s foot to just below the wearer&#39;s knee may be formed from five continuous webs and six elastomeric straps. 
     For some surgical procedures, medical personnel often wear protective coverings extending from the wearer&#39;s shoes to the knees. U.S. Pat. No. 4,093,124 entitled “Protective Shoe Covering” shows an example of such protective shoe and leg coverings. This patent is incorporated by reference for all purposes within this application. 
     For purposes of illustration, guide  108  is shown at the entrance to bonding apparatus  100  to fold first longitudinal edge  109  of continuous web  81  over elastomeric strap  87 . Bonding apparatus  100  will then form longitudinal bond  112  between first longitudinal edge  109  and an adjacent portion of continuous web  81  to provide a long, continuous loop with elastomeric strap  87  disposed therein. In a similar manner, guide  110  is provided to fold first longitudinal edge  111  of continuous web  85  over elastomeric strap  93 . Bonding apparatus  100  will then form longitudinal bond  114  between first longitudinal edge  111  and a portion of continuous web  85  to provide a long, continuous loop with elastomeric strap  93  disposed therein. 
     For the embodiment of the present invention shown in FIG. 2, second longitudinal edge  119  of continuous web  81  overlaps an adjacent portion of middle continuous web  83 . In a similar manner, second longitudinal edge  121  of continuous web  85  overlaps an adjacent portion of middle continuous web  83 . Elastomeric strap  89  is disposed between the overlapping portions of continuous web  81  and  83 . Elastomeric strap  91  is disposed between the overlapping portions of continuous web  83  and  85 . Bonding apparatus  100  forms a pair of longitudinal bonds  118  extending longitudinally parallel with each other along opposite sides of elastomeric strap  89 . A pair of longitudinal bonds  120  are formed on opposite sides of elastomeric strap  91 . 
     The overlapping configuration of continuous web  81 ,  83  and  85  allows the resulting disposable shoe cover  20  to be formed without any upwardly facing edges or seams that could possibly trap liquids or other types of contaminants. Longitudinal edges  119  and  121  will eventually be facing downward on the exterior of disposable shoe cover  20 . Longitudinal edges  123  and  125  of continuous web  83  will be disposed within the interior of disposable shoe cover  20 . For one application bonds  112 ,  114 ,  118  and  120  are preferably long thermal bonds. Thermal bonds satisfactory for use with this invention may be formed by various techniques including but not limited to ultrasonic, radio frequency, heat and pressure, impulse sealing and laser bonding. However, other bonding techniques such as sewing and/or adhesives may be satisfactorily used to form intermediate piece  102 . 
     Intermediate piece  102  is next formed into a series of blanks  40  from which disposable shoe cover  20  may be fabricated. The length of blank  40  and particularly the length of middle panel  43  is selected to correspond approximately with the length of the largest shoe that will fit within the resulting disposable shoe cover  20 . 
     For purposes of illustration, blank  40  is shown in FIGS. 3 and 4 secured between tensioners  104  and  106 . In actual practice, blank  40  will preferably remain a part of and be secured to intermediate piece  102  within a series of tensioners  104  and  106  as each blank  40  moves through different steps in the process of fabricating disposable shoe cover  20 . Tensioners  104  and  106  are provided to maintain the desired tension on elastomeric straps  87 ,  89 ,  91  and  93  until various steps associated with fabrication of disposable shoe cover  20  from blank  40  have been completed and blank  40  can be cut or released from intermediate piece  102 . 
     Blank  40  as shown in FIGS. 3-9 may be described as a generally quadrilateral sheet of material formed from three panels  41 ,  43 , and  45 . For purposes of explanation, panel  41  may sometimes be referred to as the first panel. Panel  43  may sometimes be referred to as the second panel or middle panel. Panel  45  may sometimes be referred to as the third panel. Panel  41  is formed from a portion of continuous web  81 , panel  43  from continuous web  83  and panel  45  from continuous web  85 . 
     Panels  41 ,  43  and.  45  have a generally rectangular configuration with respective longitudinal axii or center lines  42 ,  44  and  46 . Longitudinal axis  44  of panel  43  corresponds with the longitudinal axis or center line of the associated blank  40 . Longitudinal axii  42 ,  44  and  46  are arranged approximately parallel with each other and laterally offset from each other as a result of the previously described procedure for forming intermediate piece  102  from continuous webs  81 ,  83  and  85 . 
     Blank  40  includes first edge  51  and second edge  52  which are disposed opposite from each other. First edge  51  and second edge  52  extend generally parallel with respect to respective axis  42  and  46 . Blank  40  also includes third edge  53  and fourth edge  54  which are disposed opposite from each other and extend between first edge  51  and second edge  52 . Third edge  53  and fourth edge  54  also extend laterally from longitudinal axis  44  of middle panel  43 . For purposes of explanation, first edge  51  and second edge  52  may sometimes be referred to as longitudinal edges. Third edge  53  and fourth edge  54  may sometimes be referred to as lateral edges. For some applications, blank  40  may have a configuration other than quadrilateral as shown in FIGS. 3 and 4. 
     As best shown in FIG. 4, bonded areas  56  and  57  are preferably formed adjacent to respective opposite ends of first edge  51 . Bond areas  58  and  59  formed adjacent to respective opposite ends of second edge  52 . Bond areas  56  and  57  cooperate with each other to retain tension placed on the portion of elastomeric band  87  disposed adjacent to and extending along first edge  51 . Bonded areas  58  and  59  cooperate with each other to retain tension placed on the portion of elastomeric band  93  disposed adjacent to and extending along second edge  52 . 
     Bonded areas  60  and  61  are formed on the overlapping portions of first panel  41  and second panel  43  to retain tension placed on the portion of elastomeric band  89  disposed there between. Bonded areas  62  and  63  are formed on the overlapping portions of second panel  43  and third panel  45  to retain tension placed on the portion of elastomeric band  91  disposed there between. 
     Bonded areas  56  through  63  are preferably formed prior to cutting or releasing blank  40  from intermediate piece  102 . Bonded areas  56  through  63  cooperate with each other to retain respective portions of elastomeric bands  87 ,  89 ,  91  and  93  attached to blank  40 . Bonded areas  56  through  63  may either be formed within bonding apparatus  100  or may be formed on intermediate piece  102  at a later step (not expressly shown) during the fabrication of disposable shoe cover  20 . 
     The tension retained in the portion of elastomeric band  87  extending between bonded areas  56  and  57  will result in substantial gathering or bunching of first edge  51  when blank  40  is released or cut from intermediate piece  102 . In a similar manner bonded areas  60  and  61  cooperate with the portion of elastomeric band  89  extending therebetween, bonded areas  62  and  63  cooperate with the portion of elastomeric band  91  extending therebetween and bonded areas  58  and  59  cooperate with the portion of elastomeric band  93  extending therebetween to gather blank  40  when released from tensioners  104  and  106 . Therefore, blank  40  is preferably held in tension during fabrication of disposable shoe cover  20 . 
     For one application as shown in FIG. 4, bonded areas  60  and  62  are preferably formed approximately two and one-half inches from third edge or lateral edge  53 . Bonded areas  61  and  63  are preferably formed approximately four inches from fourth edge or lateral edge  54 . The distance between lateral edge  53  and bonded areas  60  and  62  is selected to accommodate the heel and quarter of a wide variety of shoe sizes and types. The distance between bonded areas  61  and  63  and lateral edge  54  is selected to accommodate the toe and vamp of a wide variety of shoe sizes and types. 
     As best shown in FIGS. 5,  6  and  7 , first panel  41  and third panel  45  are folded toward each other along longitudinal center line  44 . For one application, a generally W-shaped fold  48  is preferably formed in middle panel  43  extending along longitudinal center line  44 . Cooperation between W-shaped fold  48  and elastomeric bands  89  and  91  allows the resulting disposable shoe cover  20  to conform with the configuration of a wide variety of shoe sizes and types. 
     Folding blank  40  as shown in FIGS. 5,  6 , and  7  results in placing panels  41  and  45  in close juxtaposition with each other. Folding blank  40  also places portions  53   a  and  53   b  of lateral edge  53  immediately adjacent to each other and portions  54   a  and  54   b  of lateral edge  54  immediately adjacent to each other. Opening  30  for placing disposable shoe cover  20  on the foot of wearer  22  is defined in part by placing first longitudinal edge  51  and second longitudinal edge  52  adjacent to each other and forming bonded seams  66  and  68 . 
     As best shown in FIG. 6, bonded seam  66  is preferably formed between adjacent portions of lateral edges  54   a  and  54   b  extending from the adjacent ends of first edge  51  and second edge  52  at location  74  to W-shaped fold  48 . Bonded seam  66  joins adjacent portions of first panel  41  and third panel  45  at what will eventually be the back or heel portion of disposable shoe cover  20 . For some applications, bonded seam  66  may extend in a substantially straight line perpendicular to longitudinal center line  44 , first edge  51 , and second edge  52 . For other applications, bonded seam  66  may include a slightly inward taper or slope  67  to provide a more comfortable fit with the leg and ankle of wearer  22 . 
     As best shown in FIG. 6, bonded seam  68  is preferably formed between adjacent portions of first panel  41  and third panel  45  extending from the extreme end of W-shaped fold  48  to location  72  intermediate the ends of the first edge  51  and second edge  52 . Bonded seam  68  has a generally curved configuration that will eventually be the front or toe portion of disposable shoe cover  20 . The portion of bonded seam  68  immediately adjacent to the junction between first panel  41 , middle panel  43  and third panel  45  includes toe portion  69  with a radius of curvature selected to accommodate the toe of a wide variety of shoe sizes and types. Bonded seam  68  includes tapered portion  70  extending from toe portion  69  to location  72  intermediate the ends of first edge  51  and second edge  52 . Tapered portion  70  is sized to accommodate the vamp of a wide variety of shoe sizes and types. 
     For one application, bonded seams  66  and  68  are preferably formed while blank  40  is held in tension. After seams  66  and  68  have been formed, disposable shoe cover  20  may be released from the associated blank  40  by die cutting techniques while blank  40  is held in tension. 
     Opening  30  is further defined by the portions of first longitudinal edge  51  and second longitudinal edge  52  extending between location  72  and location  74  at which seam  66  intersects and bonds together adjacent portions of first longitudinal edge  51  and second longitudinal edge  52 . A portion of elastomeric bands  87  and  93  will be trapped in tension between location  72  and location  74 . The tension trapped in elastomeric bands  87  and  93  will assist in securing disposable shoe cover  20  on the foot of wearer  22 . 
     After portions of first panel  45 , middle panel  43  and third panel  45  have been bonded with each other as shown in FIG. 6, excess material may be cut away to provide the desired configuration for disposable shoe cover  20  as shown in FIG.  7 . Disposable shoe cover  20  is then preferably turned inside out prior to use on a wearer&#39;s foot. By turning disposable shoe cover  20  inside out, portions of seams  66  which will be adjacent to the heel and the portions of seam  68  which will be adjacent to the toe are retained within the interior of disposable shoe cover  20  to provide a better fit in cooperation with W-shaped fold  48  and to minimize any particulate contamination from seams  66  and  68 . Also, the portion of longitudinal edges  123  and  125  of continuous web  83  will be positioned within the interior of disposable shoe cover  20  leaving downwardly facing longitudinal edges  119  and  121  on the exterior of disposable shoe cover  20 . 
     An alternative configuration for folding blank  40  to form disposable shoe cover  20  is shown in FIGS. 8 and 9. For this application, middle panel  43  is simply folded in half along longitudinal center line  44  to place first panel  41  and second panel  45  in close juxtaposition with each other. Bonded seams  66  and  68  are formed as previously described and any excess material removed. For some applications, removal of the excess material may not be required. Disposable shoe cover  20 , as shown in FIG. 9, is preferably completed by inverting the bonded and cut portion of blank  40 . It may be particularly beneficial to simply fold blank  40  in half as shown in FIG. 8 when middle panel  43  comprises material that is difficult to shape into a W-type fold. 
     FIG. 10 shows blank  140  which may be described as a generally quadrilateral sheet of material formed from three panels  41 ,  143 , and  45  using techniques as previously described with respect to blank  40 . Middle panel  143  is formed from material used to form first panel  41  and third panel  45 . 
     For some applications, middle panel  143  may be formed from rubber such as shown in U.S. Pat. No. 3,308,562, entitled “Sanitary Shoe Cover of the Type Having a Conductive Sole” or slip resistant material such as shown in U.S. Pat. No. 4,598,485, entitled “Slip-Resistant Disposable Shoe Cover”. Middle panel  143  may be formed from conductive material to protect against accumulation of static electricity such as shown in U.S. Pat. No. 3,898,750, entitled “Universal Size Disposable Shoe Cover or Vinyl Material With Anti-Static Agents” and U.S. Pat. No. 3,684,922, entitled “Anti-Static Plastic Shoe Cover and Method of Making Same”. Each of the above-referenced patents is incorporated by reference for all purposes within this application. 
     For some applications, middle panel  143  may be formed from material which is stretchable in the longitudinal direction or the machine direction as the respective continuous webs move through the associate bonding apparatus  100 . Panel  143  may also be stretchable in the lateral direction or cross-direction. Forming middle panel  143  from such stretchable material may allow reducing the total amount of material required to form a disposable shoe cover that can be used with the same range of shoe sizes and types. Various woven and non-woven materials are available that can be stretched in the machine direction and/or the cross-direction. If desired, panels  41 ,  143  and  45  may be formed from such stretchable material. 
     For other applications, middle panel  143  may be formed from a composite material having multiple layers. For example, the exterior surface of panel  143  may be formed by a layer of adhesive film to provide a sticky or tacky surface for walking and another layer may be formed from stretchable material as previously described. The present invention allows selecting material to form panel  143  with a tacky film surface on both the interior and the exterior. Thus, the resulting disposable shoe cover  20  may be fabricated with a suitable coefficient of friction provided by the exterior of panel  143  for safe walking and a suitable coefficient of friction between the interior of panel  143  and shoe  22  to prevent sliding of shoe  22  within disposable shoe cover  20 . Composite materials having the previously discussed characteristics are available from various manufacturers including Tredegar Film Products, 1100 Boulders Parkway, Richmond, Va. 23225. 
     Blank  240 , as shown in FIG. 11, may be described as a generally quadrilateral sheet of material formed from a single, continuous web (not expressly shown). The width of this single continuous web will be approximately equal to the combined width of continuous webs  81 ,  83  and  85  as shown in FIG.  2 . Portions of blank  240  are gathered together to form long, continuous loops or sleeves  222 ,  224 ,  226  and  228  by respective longitudinal bonds  223 ,  225 ,  227  and  229 . Elastomeric straps  87 ,  89 ,  91  and  93  are preferably disposed within the respective sleeve  222 ,  224 ,  226  and  228 . Sleeve  222 ,  224 ,  226 , and  228  cooperate with each other to divide blank  240  into three panels  241 ,  243  and  245  similar to previously described panels  41 ,  43  and  45 . Blank  240  may then be formed into disposable shoe cover  20  as previously described with respect to blank  40 . 
     Blank  340 , as shown in FIG. 12, may be described as a generally quadrilateral sheet of material formed from a single, continuous web (not expressly shown). The width of this single continuous web will be approximately equal to the combined with of continuous webs  81 ,  83  and  85  as shown in FIG.  2 . Portions of elastomeric straps  87 ,  89 ,  91 , and  93  are directly bonded to blank  340  by respective longitudinal bonds  323 ,  325 ,  327  and  329 . The bonded portions of elastomeric bands  87 ,  89 ,  91  and  93  cooperate with each other to divide blank  340  into three panels  341 ,  343 , and  345  similar to previously described panels  41 ,  43  and  45 . Blank  340  may then be formed into disposable shoe cover  20  as previously described with respect to blank  40 . 
     Blank  440 , as shown in FIG. 13, may be described as a generally quadrilateral sheet of material formed from a single, continuous web (not expressly shown). The width of this single, continuous web will be approximately equal to the combined width of continuous webs  81 ,  83  and  85  as shown in FIG.  2 . Four continuous strips of relatively narrow material (not expressly shown) may be used to form casings  422 ,  424 , and  426  and  428  on panel  440 . Each casing  422 ,  424 ,  426  and  428  is preferably secured to blank  440  by a respective pair of longitudinal bonds  418 . Portions of elastomeric bands  87 ,  89 ,  91  and  93  are preferably disposed within respective casings  422 ,  424 ,  426  and  428 . Appropriate bonded areas (not expressly shown) may be formed to trap the desired amount of tension in the respective elastomeric bands  87 ,  89 ,  91  and  93 . Casings  422 ,  424 ,  426  and  428  cooperate with each other to divide blank  440  into three panels  441 ,  443  and  445  similar to previously described panels  41 , 43  and  45 . Panel  440  may then be formed into disposable shoe cover  20  as previously described with respect to blank  40 . 
     A further alternative configuration for folding blank  40  is shown in FIG.  14 . For this application, middle panel  43  remains essentially flat or not folded and first panel  41  and second panel  45  are folded along their respective longitudinal center lines  42  and  46  with a portion extending essentially normal or perpendicular to middle panel  43 . This type of fold results in lateral edges  53  and  54  having a generally T-shaped configuration. The adjacent portions of lateral edges  53  and  54  may be bonded with each other to retain the generally T-shaped configuration during the remaining fabrication steps associated with forming disposable shoe cover  20 . Seams (not expressly shown) similar to previously described seams  66  and  68  may then be formed in adjacent portions of panels  41  and  45 . Blank  40  may then be formed into disposable shoe cover  20  as previously described. 
     Continuous webs  81 ,  83  and  85  may be formed from a wide variety of materials such as textiles, nonwoven, woven, paper, plastic films and composites of these materials. Specific examples include canvas, polyethylene film backed nonwoven fabric, paper products such as “Tyvek” available from E.I. duPont Nemours and Company, polytectofluoralethylene, spunbounded polypropylene, meltblown polypropylene, and fiber glass composites. 
     For some applications, continuous webs  81 ,  83  and/or  85  may have two or more layers of material that have been laminated to each other. Fiber glass may be included as one layer to provide protection in potentially harsh chemical environments. Examples of fibrous nonwoven webs formed from two or more layers of material that may be satisfactorily used with the present invention are shown in U.S. Pat. No. 5,490,846, entitled “Surge Management Fibrous Nonwoven Web for Personal Care Absorbent Articles and the Like”; U.S. Pat. No. 5,362,306, entitled “Surgical Stockinette”; U.S. Pat. No. 5,409,761, entitled “Breathable Nonwoven Composite Barrier Fabric and Fabrication Process”; and U.S. Pat. No. 5,486,166, entitled “Fibrous Nonwoven Web Surge Layer for Personal Care Absorbent Articles and the Like”. Each of these previously noted patents is incorporated for all purposes within this application. 
     An additional preferred embodiment of the disposable shoe cover  20  according to the present invention is illustrated generally in FIGS. 15-16 and  18 - 19 . In this particular preferred embodiment, bonded back or heel seam  66  is also formed between adjacent portions of lateral edges  54   a  and  54   b  extending from the adjacent ends of first edge  51  and second edge  52  (referring to the blanks of FIGS. 4-5,  8 , and  10 ). As discussed above, in relation to FIGS. 5 and 6, seam  66  may extend in a substantially straight or vertical line with respect to longitudinal center line  44  of middle panel  43 , and may also include a slightly inward taper or sloped section, 67  to provide a more comfortable fit with the leg and ankle of the wearer. 
     This particular embodiment also includes an angled seam section  66   b  that angles to the longitudinal center line of middle panel  43  in a direction towards the toe section of shoe cover  20 . Referring particularly to FIGS. 15 and 16, angled seam section  66   b  is angled directly to the fold point  49  in middle panel  43 . In other words, referring to FIGS. 15 and 16, reference character  49  indicates the end of the longitudinal W-shaped fold  48  in the sole portion of middle panel  43 . Thus, angled seam section  66   b  is formed from sealed adjacent edges  54   a  and  54   b  of middle panel  43 . 
     In the embodiment illustrated, angled seam section  66   b  extends from vertical seam section  66   a.  However, it should be understood that the entire back or heel seam  66  could comprise a generally arcuate seam that angles or curves towards longitudinal center line  44  in generally the same manner as angled seam section  66   b.  A presently preferred ratio of rise to run for angled seam section  66   b  is about 1⅜ inches to 2 inches in an embodiment designed to fit shoes of varying width and size. 
     The shoe cover  20  incorporating angled seam section  66   b  is not limited to an embodiment of the present invention incorporating three separate panels, but is just as applicable to a disposable shoe cover formed from a single continuous web of material, for instance as described in relation to FIGS. 11 through 13 above. 
     FIG. 17 illustrates the disposable shoe cover  20  according to the embodiment of FIG.  1 . In this embodiment wherein seam  66  extends generally vertically or perpendicular to the longitudinal center line of middle panel  43 , the bottom or sole portion of middle panel  43  will form a “bunch”  66   c  at location  49  defining the end of the fold, particularly the W-shaped fold  48 . This bunched portion  66   c  is a result of the fact that middle panel  43  does not incorporate additional lateral seams or seals extending across the width of the sole portion. Such additional seams would add substantially to the manufacturing cost and complexity of shoe covers  20  according to the invention. Although the embodiment of the present invention illustrated in FIG. 17 is particularly useful in many applications, the bunched portion  66   c  of middle panel  43  may be undesirable in certain situations, particularly wherein bunched portion  66   c  may tend to fold under the sole of the shoe cover. In this situation, the bunched portion  66   c  may become bothersome to the wearer as might a pebble or stone under the sole of the shoe. If the bunched portion  66   c  extends rearward from the shoe, as illustrated in FIG. 17, it is possible that this bunched portion can become caught in equipment or under rollers of various devices or equipment. 
     Referring to FIGS. 18 and 19, it can be seen that the embodiment of shoe cover  20  according to FIGS. 15 and 16 ensures that bunched portion  66   c  of middle panel  43  is always disposed along the back portion of the shoe. When this particular embodiment is placed on the foot of a wearer, the back edge  26   a  of the heel will slide down angled seam section  66   b  when the shoe cover is pulled upward from location  74 . Thus, angled seam section  66   b  is pulled upwards along the back portion of the shoe such that the end location  49  of the fold in middle panel  43  is also disposed along the back portion of the shoe. The entire shoe cover  20  is pulled essentially rearward and upward so that longitudinal seam  91  bends or angles towards the ankle of the wearer causing the bunched portion  66   c  to essentially wrap around the back edge of the heel from location  49  along fold lines  66   d.  This particular construction of shoe cover  20  thus forces the toe section of the shoe cover to conform more tightly against the toe of the shoe, at least to the extent that angled seam section  66   b  is offset or angled towards the toe section along the “run” thereof. In this regard, referring to FIGS. 15 and 16, the distance of middle panel  43  between the toe section and location  49  defines the maximum length of the shoe compatible with shoe cover  20 . 
     Although the present invention and its advantages have been described in detail with respect to alternative embodiments, various changes and modifications may be suggested to one skilled in the art. It should be understood that various changes, substitutes, and alterations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.