Abstract:
Work footwear includes a work shoe and a resilient anti-fatigue layer shaped to fit under the sole and heel of a shoe of a wearer with a cover member elastically attached to the shoe to trap the layer therebetween. The layer is separate from the cover for ready replacement. When used in a contaminated area the cover member has a peripheral wall to seal the area between the cover and the shoe against penetration of moisture. When used in an uncontaminated environment, the layer may be received in a cupped shape of the cover member with elastic strap portions engaging over the foot to hold the cover and layer in place.

Description:
[0001]     This application is a continuation-in-part application from application Ser. No. 10/929,719 filed Aug. 31, 2004 which is a continuation-in-part of application Ser. No. 10/792,386 filed Mar. 4, 2004 and is a continuation-in-part application from application Ser. No. 10/385,294 filed Mar. 11, 2003 and is a continuation-in-part application from application Ser. No. 10/097,645 filed Mar. 15, 2002, the disclosure of which is incorporated herein by reference. 
     
    
       [0002]     The present invention relates to a resilient sole insert which can be attached underneath the shoe of a wearer by an attachment member for purposes of providing a layer underneath the shoe for additional resilience.  
       BACKGROUND  
       [0003]     There has been much research that shows a direct relationship between comfort, safety, and productivity in the workplace. In situations where long periods of standing exist, worker discomfort and fatigue can negatively impact productivity, absenteeism, and healthcare costs. Standing requires about 20 percent more energy than sitting. The foot is a very complex organ, a structure of 26 bones, or 12.5% of all the bones in the entire body, 56 ligaments, 38 muscles and over 7000 nerve endings. It is essential to recognize that your feet are sensitive parts of your body deserving good care. Being farthest from the heart, the feet generally have the poorest circulation in the body and this diminishes with age Depending on the floor surface and the amount of time workers are standing, employees can ‘feel drained’ and experience poor blood circulation in feet and legs. This may lead to serious consequences for health and safety at the work place. Beyond discomfort, pain and fatigue sets up the worker for further injuries affecting the muscles and joints. In addition an employee who is suffering from pain and fatigue is less alert and more likely to act in an unsafe manner.  
         [0004]     Anti-fatigue mats have been designed to provide effective shock attenuation to address this problem. These mats are made of various materials including rubber, vinyl, wood and carpeting materials. By alleviating pressure, it can help stimulate blood circulation and possibly reduce stress of the lower back, leg joints, and major muscle groups. The result is an improved workplace with fewer occupational health complaints.  
         [0005]     One anti-fatigue mat is available from 3M which is formed of a layer of intermingled course strands of heat bondable flexible plastics or rubber material which fibers are bonded together at crossing points to form an interconnected mat. One surface of the layer is relatively flat and the bonding effect is more pronounced with some of the strands clearly melted in the bonding process to form a tight surface while the other surface is looser and the strands less bonded together so that the strands are loose at the surface and stand out from the surface. This mat is commercially available and widely used as a floor covering for commercial floors for purposes of reducing fatigue in workers required to stand and work on the floor for extended time periods. The mat is applied to the floor surface such as concrete with the tight surface in contact with the floor and the loose surface facing upwardly. This mat is resistant to wear and to damage from commercial use including material spills and thus is widely used.  
         [0006]     Many anti-slip soles are available for workplaces or exterior use but these are generally formed as a shoe to be worn on the foot of the wearer rather than as a strap on cover. Examples are manufactured by Shoes for Crews Inc. and Skid Busters. These provide soles with nubs or projections on the bottom surface which tend to be more slip resistant and tend to prevent or inhibit the accumulation of ice and snow.  
         [0007]     One example of a strap on cover is shown in Canadian Application 2,421,460 by the present applicant which was published Sep. 11, 2003, the disclosure of which is incorporated herein by reference.  
       SUMMARY OF THE INVENTION  
       [0008]     It is one object of the present invention to provide an improved footwear for providing a layer under the shoe sole on which the wearer can walk.  
         [0009]     According to the present invention there is provided footwear comprising: 
        a resilient, anti-fatigue, flexible layer shaped to fit under the sole and heel of a shoe of a wearer;     a shoe cover member for enclosing the layer between the cover member and the shoe;     the shoe cover member having a sole plate shaped to underlie the shoe of the wearer with an outer peripheral edge of the sole plate exposed around the shoe;     the layer being separate from the cover member for ready removal and replacement of the layer;     and elastic attachment portions connected around the sole plate and elastically stretchable for engaging over the shoe of the wearer for fastening the flexible layer to the foot of the wearer.        
 
         [0015]     Preferably the sole plate is thin and flat with a flat bottom surface of the layer lying on a flat upper surface of the sole plate.  
         [0016]     Preferably the elastic attachment portions are sealed to the sole plate to prevent penetration of moisture between the sole plate and the shoe and into the layer.  
         [0017]     Preferably the elastic attachment portions extend around the full periphery of the sole plate.  
         [0018]     Preferably the elastic attachment portions hold the sole plate and layer in place under the shoe solely by elastic engagement without fastening elements.  
         [0019]     Preferably the elastic attachment portions include portions extending along the sides and around the heel of the shoe and a portion extending over the toe of the shoe.  
         [0020]     Preferably the elastic attachment portions include a heel portion for wrapping around the heel of the wearer, two side portions and a toe portion for engaging over the toe, there being provided spaces between the portions such that the portions connect separately to the sole plate.  
         [0021]     Preferably the heel portion extends from a connection at each side to the side of the sole plate around the heel, wherein the side portions extend from the sides over the arch of the shoe and wherein the toe portion forms a toe receptacle into which the toe of the shoe extends.  
         [0022]     Preferably each of the elastic attachment portions is stretchable to engage over the shoe of the wearer without fastening elements.  
         [0023]     Preferably the sole plate includes an upturned peripheral edge such that the edge receives and edge of the layer and contains the layer.  
         [0024]     Preferably the upturned peripheral edge includes an in-turned lip for retaining the layer in the cover member.  
         [0025]     Preferably the layer has a recess for receiving the in-turned lip.  
         [0026]     Preferably the layer is fastened into the cover member at the sole plate by releasable fastening elements.  
         [0027]     Preferably the layer has a thickness in the range between 6 mm and 14 mm.  
         [0028]     Preferably the layer has a hardness durometer in the range between 35 and 55.  
         [0029]     Preferably the layer has acompressibility in the range, using the ASTM D575 test to determine an ideal level of compression set in the range between 15% and 45%.  
         [0030]     Preferably the layer comprises a resilient mat defined by resilient polymer fibers heat bonded together.  
         [0031]     According to a second aspect of the invention there is provided work footwear for use in a contaminated area comprising: 
        a work shoe for wearing on the foot of the wearer;     a resilient, anti-fatigue, flexible layer shaped to fit under the sole and heel of the shoe;     a shoe cover member for enclosing the layer between the cover member and the shoe;     the shoe cover member having a sole plate shaped to underlie the shoe with an outer peripheral edge of the sole plate exposed around the shoe;     the layer being separate from the cover member for ready removal and replacement of the layer;     and elastic attachment portions connected around the sole plate and elastically stretchable for engaging over the shoe of the wearer for fastening the flexible layer to the shoe.        
 
         [0038]     19. The footwear according to claim  18  wherein the elastic attachment portions are sealed to the sole plate to prevent penetration of moisture between the sole plate and the shoe and into the layer. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0039]     In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:  
         [0040]      FIG. 1  is a side elevational view of a light weight footwear construction to be used over shoes generally in a clean internal environment to provide an anti fatigue layer underneath the shoe.  
         [0041]      FIG. 2  is an exploded view of the footwear of  FIG. 1 .  
         [0042]      FIG. 3  is a first cross sectional view showing the construction of the footwear of  FIG. 1 .  
         [0043]      FIG. 4  is a second cross sectional view showing a modified arrangement for the cross section of the footwear of  FIG. 1 .  
         [0044]      FIG. 5  is a longitudinal cross sectional view of footwear for use in a contaminated work environment.  
         [0045]      FIG. 6  is a cross sectional view of the footwear of  FIG. 5  in a transverse direction. 
     
    
     DETAILED DESCRIPTION  
       [0046]     In  FIGS. 1, 2  and  3  is shown a first embodiment of footwear according to the present invention.  
         [0047]     This footwear is intended for relatively lightweight duty in an interior situation where there is little or no contamination so that the area is relatively clean. Such a situation might be a hospital where workers are required to stand to stand for extensive periods of time so that the use of an anti-fatigue matting to reduce the fatigue of standing and walking would be desirable.  
         [0048]     As disclosed in the above published Canadian application, anti-fatigue matting can be attached to the foot of the wearer underneath the existing shoe of the wearer as simply a mat element which is attached to straps engaging over the foot and footwear to hold the anti-fatigue mat on the underside of the shoe of the wearer.  
         [0049]     Such anti-fatigue mats are preferably of the type which utilize fibrous elements which are heat bonded together. Such material is well known and is formed from polymer fibres which are arranged in random orientation as an entangled mat of the fibres which are then heat bonded together so that each fibre is bonded to the whole series of fibres in the remainder of the mat so that the whole mat is bonded together by each crossing fibre being attached to the next crossing fibre with air spaces therebetween. It is well known that such matting provides an effective resilient layer, needs floor matting over a concrete floor to provide a resilient action for a person walking on the concrete to reduce fatigue. Matting of this type is well known and available from a number of different manufacturers and primarily from 3M.  
         [0050]     As an alternative, the very resilient matting defined above can be replaced by a foam material such as EVA or polyurethane. While such matting is unsuitable generally as matting delay on the floor, it can be cut into pads to be placed under the footwear of a wearer to provide an anti-fatigue layer.  
         [0051]     Such a layer preferably has a thickness in the range between 6 mm and 14 mm. Such a layer preferably has a hardness durometer in the range between 35 and 55. Such a layer has preferably a compressibility in the range, using the ASTM D575 test to determine an ideal level of compression setting the range between 15% and 45%.  
         [0052]     These figures provide a foam layer which is particularly suitable for an anti-fatigue layer in that it provides resilience and spring-back to the foot and shoe of the wearer when placed onto the layer rather than directly onto the ground surface.  
         [0053]     The present invention provides techniques for attachment of the layer defined above to the underside of the shoe of the wearer.  
         [0054]     In the embodiment of  FIG. 1 , a cup-shaped sole plate generally indicated at  10  includes a flat base  11  and upstanding side wall  12  surrounding the flat base  11 . The upstanding side walls surround the full periphery of the flat base  11 . The flat base is substantially of constant thickness across its full extent but may include ribs and grooves  13  on the underside to present an anti-slip surface.  
         [0055]     The depth of the side wall  12  is sufficient to receive substantially the whole of the layer which is indicated at  14 .  
         [0056]     At the top of the side wall  12  is provided an in-turned lip  15  which extends generally horizontally parallel to the base  11  into the side edge  16  of the layer  14 . The side edge  16  may include a recess  17  so that the lip projects into the recess thus engaging the layer  14  at its side edges to hold the layer downwardly into the cup shaped sole plate.  
         [0057]     The layer  14  is of constant thickness and is shaped to underlie the shoe of the wearer. Different sizes of the footwear can be formed to accommodate different sizes of shoe. In general a limited number of different sizes will be provided to match certain ranges of shoe size of the wearer.  
         [0058]     The footwear is completed by an upper generally indicated at  18  which is formed by molding from an elastic material so that it can be stretched into place over the shoe of the wearer. The upper  18  includes a bottom band  19  around the bottom edge which cooperates with the side wall  12  of the sole plate so that the two elements are attached together permanently uniting the upper with the sole plate.  
         [0059]     In the embodiment of  FIG. 3 , the band  19  extends inwardly of the side wall  12  and between the side wall  12  and a retaining ring  20  on which the lip  15  is formed. Thus the band  19  is adhesively bonded between the upstanding edge  12  and the additional ring  20  with these three elements being attached together to permanently hold the band  19  of the upper  18  in place attached to the sole plate.  
         [0060]     The upper  18  includes a heel portion  22 , an arch portion  23  and a toe portion  24  all of which extend from the band  19  and extend over the foot of the wearer to elastically hold the upper in place over the top of the foot while the cup shape sole plate lies underneath the foot and shoe of the wearer. The heel portion  22  is connected to the band  19  at side pieces  25  and extends therefrom around the rear of the heel of the wearer. The arch portion  23  extends downwardly to the sides at connections  26  and  27  to the band and extends therefrom over the arch of the foot of the wearer into strap portions  28  and  29  which elastically extend over the arch of the foot of the wearer. The toe piece  24  forms in effect a toe cap which is perforated  30  at the front and  31  and  32  at the sides. Thus the toe cap is connected to the band  19  at a series of spaced positions around the band and forms an edge  33  which extends generally over the toe area of the shoe of the wearer.  
         [0061]     Each of these three portions is formed from an elastic material such as rubber which can be readily stretched so as to pull the structure into place without the necessity for straps and fastenings which require to be connected together by buckles or hook and loop fasteners or the like. Thus the attachment is merely by the elastic stretching and the frictional engagement of the three elements over the foot of the wearer.  
         [0062]     The holes between the connections around the band  19  provides an attractive appearance and also reduce the weight of the structure. In addition the holes allow additional stretching action since the holes define simply relatively narrow straps of the pieces which can be pulled and stretched as required by the user to fit over heavier footwear or larger feet as required.  
         [0063]     The band  19  is sealed into the sole plate so that the holes are located at or closely adjacent the top edge of the sole plate. The foot and shoe of the wearer are thus exposed at the holes to allow air penetration to the foot and shoe thus reducing the tendency to overheat the foot of the wearer.  
         [0064]     In  FIG. 4  is shown a modified arrangement in which the lip  15  is molded on the inside surface of the upper at the top of the band  19 . In this arrangement there is no additional molded ring  20  and the attachment between the upper and the sole plate is provided by the single bonding action between the band  19  and the upstanding side wall  12 .  
         [0065]     Also in  FIG. 4  the layer  14 A is formed as two separate sections  14 B and  14 C. These have different characteristics so that the upper layer  14 C may be a more resilient or softer foam whereas the lower layer  14 B provides the majority of the physical characteristics defined hereinbefore. The lip  15 A extends into a recess  16 A defined generally between the upper portion  14 C and the lower portions  14 D at the junction therebetween.  
         [0066]     Turning now to  FIGS. 5 and 6  there is shown a modified arrangement which is intended for use in more contaminated areas for work footwear. Such areas can include areas such as meat packing plants where the floor can be contaminated with animal materials. Other such contaminated areas may include heavily contaminated workshops where oil or other liquids can be found on the floor.  
         [0067]     The previously described arrangement of matting set forth in the above prior Canadian application provides the required anti-fatigue characteristics but the matting itself is exposed to the floor so that it can become contaminated and difficult to clean.  
         [0068]     In the present arrangement, therefore, the matting layer indicated at  30  which may be of the fibre type or the foam type described above is contained between the sole  31  of a shoe  32  of the wearer and an undersole or sole plate  33  attached onto the shoe  32 . The sole plate  33  has a characteristic of a toe rubber so that it has a bottom wall  34  which lies flat on the ground surface and an upstanding peripheral wall  36  which is arranged to form an enclosure around the bottom plate  34  and to fully enclose the lower part of the shoe of the wearer. The upstanding band  36  includes a portion  36 A which extends over the toe of the shoe  32  to provide elastic engagement with the shoe. The structure is held in place simply by the elastic arrangement of the surrounding band  36 . The surrounding band  36  defines a seal around the plate  34  so that material on the floor, unless it extends over the top edge of the band  36 , cannot penetrate into the area between the sole plate  34  and the bottom of the sole  31  of the shoe. Thus the layer  30  is maintained protected against contamination. The band  36  has an upper edge  38  which can be stretched to allow the foot of the wearer to be inserted. The foot is inserted under the toe section  36 A and then the heel is pulled up around the shoe of the wearer with sufficient tension around the upper edge  38  to hold the band  36  and the sole plate  34  in place without the necessity for additional fastening elements or straps.  
         [0069]     The underside of the sole plate  34  may have ribs or recesses to provide an anti slip effect. The layer  30  is flat so that it defines a flat upper surface  30 A onto which the sole  31  and heel  31 A of the shoe of the wearer are placed.  
         [0070]     The shoe is preferably a work-type boot which provides initial work protection such as protection against falling objects or cutting so the boot may contain steel or other resisting material as is well known. In addition to the work boot, the outer layer provided by the sole plate  34  and the band  36  together with a layer  30  provides an enhanced anti-fatigue effect for the conventional workboot.  
         [0071]     The layer  30  can in some arrangements be simply placed into the underlying structure so as to be trapped between the shoe  32  and the sole plate  34 . However additional fastening elements  40  may be provided such as hook and loop fasteners to hold the layer down in place on the sole plate  34 .  
         [0072]     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.