Patent Publication Number: US-8109050-B2

Title: Flooring apparatus for reducing impact energy during a fall

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a non-provisional application claiming priority from U.S. Provisional Application Ser. No. 60/771,630, filed Feb. 9, 2006, entitled “SorbaShock Pressure Reduction Flooring” and from U.S. Provisional Application Ser. No. 60/793,457, filed Apr. 20, 2006, each of which is incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to cushioned flooring systems, and in particular to a flooring apparatus for reducing impact energy during a fall. 
     BACKGROUND OF RELATED ART 
     It is known that falls represent a leading cause of non-fatal injuries in the United States (Cost of Injury, 1989). In 1985, for example, falls accounted for an estimated 21% of non-hospitalized injured persons (11.5 million people) and 33% of hospitalized injured persons (783,000 hospitalizations). In addition 9% of fatalities (12,866 deaths) were related to falls. Some estimates have said that the cost of fall related injuries in the United States in 2000 was approximately $20 billion dollars. 
     A number of epidemiological studies report a drastic increase of fall incidence rate in the population over the age of 65, suggesting a direct relationship between aging and the frequency of fall events (Sorock, 1988; Healthy People 2000, 1990; Injury Prevention: Meeting the Challenge, 1989; National Safety Council, 1990; Grisso et al., 1990; DeVito et al., 1988; Waller, 1985; Waller, 1978; Sattin et at., 1990). Although the exact incidence of non-fatal falls is difficult to determine, it has been estimated that approximately 30% of all individuals over the age of 65 have at least one fall per year (Sorock, 1988). 
     When the dramatic growth in the number of people over 65 and their proportion in the population is considered, this represents a significant health problem. By some estimates, this age group currently makes up 12.4% of the U.S. population, with a projected increase to 19.6% by the year 2030 (Federal Interagency Forum on Aging-Related Statistics, 2004). Of particular note is the growth of the “oldest old” (i.e. those people over 75). In the decade between 1990 and 2000, the greatest growth in the over 55 age group was projected to be among those 75 and older—an increase of 26.2 percent or a gain of nearly 4.5 million (U.S. Dept. of Commerce, Bureau of Census, 1988). 
     In Injury in America (1985, p. 43) the authors stated that “Almost no current research deals with the mechanisms and prevention of injury from falls (the leading cause of non-fatal injury) . . . Little is known about the effectiveness of energy-absorbing materials, either worn by persons at high risk or incorporated in the surfaces onto which they fall.” 
     Typically, current approaches to solving the problem of injury from falls include devices which use composite matting to absorb energy resulting from patient/floor impact during falls. For example, U.S. Pat. Nos. 3,636,577, 4,557,475, 4,727,697, 4,846,457, 4,948,116, 4,991,834 and 4,998,717, each describe impact absorbing coverings which utilize air-filled cells or compressible materials to absorb the energy of a fall. Because each of these systems is always compliant (i.e., always deformable under compressive pressures), shoes, feet, and/or other contacts with the flooring surface results in relatively large mat deflections. This has the potential to increase the likelihood of falls due to toe/mat interference during foot wing, and/or presents a problem when an individual attempts to move an object over the floor (e.g., a wheelchair). These factors can be of even greater concern in a health care setting, where many residents may have an unsteady gait and/or utilize wheel chairs for locomotion. 
     The disclosed floor overcomes at least some of the above-described disadvantages inherent with various apparatuses and methods of the prior art. The example floor includes a flooring system which requires no special clothing or restriction of movement because the floor will act as the injury prevention system. The design incorporates a stiffened floor which remains substantially rigid under normal conditions and deflects under impact (i.e., a pressure greater than a predetermined critical pressure) to absorb the energy of the impact. Accordingly, the examples floor offers a novel and effective system to reduce injuries from falls. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of an example flooring apparatus for reducing impact during a fall. 
         FIG. 2  is a bottom side view of the flooring apparatus of  FIG. 1  with a portion of the underlayment removed. 
         FIG. 3  is a side elevational view of the example flooring apparatus of  FIG. 1  showing the floor being subjected to a compressive pressure under normal conditions. 
         FIG. 4  is a side elevational view of the example flooring apparatus of  FIG. 1  showing the floor being subjected to a compressive pressure under impact conditions. 
         FIG. 5  is a side elevational view of another example flooring apparatus for reducing impact during a fall. 
         FIG. 6  is a bottom side view of the flooring apparatus of  FIG. 5  with a portion of the underlayment removed. 
         FIG. 7  is a side elevational view of the example flooring apparatus of  FIG. 5  showing the floor being subjected to a compressive pressure under impact conditions. 
         FIG. 8  is a side elevational view of the flooring apparatus of  FIG. 5  including a tile overpayment. 
     
    
    
     DETAILED DESCRIPTION 
     An impact-absorbing flooring system is described, with applications in various areas where there is a risk of injury due to fall and/or high-impact. For instance, the flooring system may be utilized in healthcare facilities, in sports facilities, and/or in any other commercial or residential environment. The floor may be manufactured as a single continuous floor, or may be manufactured as a modular tile that may be combined with adjoining tiles to form a floor surface. The flooring system may also take the form of a safety mat or coating for use around slippery areas, such as, for example, bathtubs, showers, swimming pools, etc. 
       FIGS. 1 and 2  together illustrate an example flooring apparatus  10 . The apparatus  10  may provide a significant reduction in peak impact pressure during falls, yet retains a substantially non-compliant configuration during normal pressures. In particular, in the illustrated example, the apparatus  10  includes a flooring plate  20  having a plurality of spaced apart stiffening columns  22 , extending from an undersurface  26  of the flooring plate  20 . Each of the columns  22  may be integrally formed with the plate  20 , or may be coupled to the plate  20  as desired. In the illustrated example, the stiffening columns  22  are generally rectangular and extend generally perpendicular to the plate  20 . In this example, the columns are spaced at generally  90 ° to one another. It will be appreciated, however, that the angle from which the columns  22  extend from the plate  20 , as well as the pattern of the columns  22  may be varied as desired. Furthermore, while the columns  22  are illustrated as separate bodies, the columns could be coupled via bridge-like connections, or otherwise connected together to form a straight and/or curvilinear rib  23  (see, for example,  FIGS. 1 ,  2 ). 
     The stiffening columns  22  are at least partially (and possible completely) surrounded by a resilient underlayment  24 . The underlayment  24  may cover at least a portion of the undersurface  26  of the flooring plate  20  and may be secured thereto. Additionally, the underlayment may be secured to at least one of the columns  22 . The columns  22  and/or the underlayment  24  (together or separately) are adapted to support the flooring plate  20  at a normal H above a support surface  28 , such as for example, a sub-floor. 
     The flooring plate  20  may be constructed of any suitable material including, for example, wood, metal, thermoplastic, such as polyester, polypropylene, and/or polyethylene, and/or any other suitable material. Similarly, the plate  20  may be formed by any suitable manufacturing process, including, for instance, molding, stamping, rolling, etc. Additionally, while in this example the stiffening columns  22  are integrally formed with the plate  20 , it will be appreciated by one of ordinary skill in the art that the columns  22  may be constructed of any appropriate material and as noted above, may be attached to the undersurface  26  via any suitable method, such as, for example, adhesive, mechanical, and/or other comparable fasteners. 
     In the illustrated example, the resilient underlayment  24  is a foam material, such as, for example, a polymer foam. However, it will be appreciated by one of ordinarily skill in the art that the resilient underlayment  24  may be formed from any suitably resilient material, and/or composite material. Furthermore, resilient underlayment  24  may also be secured to the undersurface  26  of the flooring plate  20  and/or the columns  22  by adhesion, mechanical connection, and/or any other appropriate method. 
     Turning now to  FIGS. 3 and 4 , the flooring apparatus  10  is illustrated under the influence of two different compressive pressures. In  FIG. 3 , the flooring apparatus  10  is subjected to a compressive pressure P n  distributed over the plate  20  under normal conditions, wherein the pressure P n  is under a predetermined critical pressure (i.e., the pressure at which the column  22  will buckle). For example, the pressure P n  may be the distributed pressure of an individual (or object) walking, standing, running, or otherwise moving over the plate  20 . Under these conditions, the plate  20  of the apparatus  10  will not deflect in any appreciable manner, but rather the stiffening columns  22  will remain substantially rigid and will support the plate  20  at the normal height H above the support surface  28 . 
     In  FIG. 4 , the flooring apparatus  10  is subjected to a compressive pressure P i  distributed over the plate  20  under impact conditions, wherein the pressure P i  is over the predetermined critical pressure (i.e., the pressure at which the column  22  will buckle). For example, the pressure P i  may be the distributed pressure of an individual falling on or otherwise impacting the plate  20 . Additionally, while described as an impact pressure, the pressure P i  need not result from impact, but rather may be any pressure, such as, for example, a static pressure. Under these conditions, a portion of the plate  20  of the apparatus  10  will deflect toward the support surface  28  (such as for example to a height H′) and the stiffening columns  22  will buckle and deflect to absorb the energy of the impact. The columns  22  may, therefore, be the primary means of energy absorption, while the resilient nature of the underlayment  24  may provide a secondary means of energy absorption as the apparatus  10  deforms. After the impact pressure is removed, or otherwise dissipated, the apparatus  10  will substantially return to its original state and the plate  20  will once again be supported at the typical height H above the support surface  28  ( FIG. 1 ). 
     Referring again to  FIG. 2 , the apparatus  10  of  FIG. 1  is illustrated in a bottom side view, with a portion of the underlayment  24  removed to expose the plate  20 . As illustrated, the columns  22  in this example have a generally rectangular cross-section, but it will be understood that the cross section may vary as desired. For example, because the stiffness of each of the columns  22  is directly proportional to the area moment of inertia of that column, in this example the stiffness of each column is generally greater in the y-direction than in the x-direction. Similarly, the because the columns  22  are at least partially encapsulated in the underlayment  24 , the properties of the underlayment  24 , the properties of the underlayment  24  aid in the control of the buckling pressure and the post-buckling deformation of the columns  22 . 
     The critical pressure (e.g., the magnitude of the compressive pressure at which the column  22  will buckle) is determined by a number of factors, including, for example, the column  22  will buckle) is determined by a number of factors, including, for example, the column length, width, area moment of inertia, material properties, the boundary conditions imposed at the column end points, the distribution of the columns on the plate  20 , the angle at which the columns extend from the plate  20 , and/or the properties of the underlayment  24 . In one example, a desired predetermined critical pressure may be approximately 20 lbs/in 2 . Because the critical pressure at which buckling of each of the columns  22  will occur is determined by many factors, it is possible to vary the design of the columns  22  and/or the underlayment  24  for a specifically desired critical pressure by varying some or all of these parameters utilizing known analysis methods such as Euler calculations and/or finite element analysis. Therefore it is possible to configure the columns  22  and/or the underlayment  24  so that the flooring apparatus  10  will remain relatively rigid under normal pressure but will buckle under impact pressures typically sustained during a fall. Varying the parameters of the columns  22  and/or the underlayment will permit construction of multiple embodiments having various uses from private dwellings, bathrooms, and geriatric homes to hospital and athletic events where impact pressures are expectedly variable. 
       FIGS. 5 and 6  illustrate another example of a flooring apparatus  100  similar to the flooring apparatus  10  of  FIG. 1 , but including a stop to prevent over-deformation. In particular, the apparatus  100  includes the flooring plate  20  having the plurality of spaced apart stiffening columns  22 , extending from the undersurface  26  of the flooring plate  20  as described above. The apparatus  100 , however, further includes a plurality of spaced apart deflection stops, such as stop columns  127 , additionally extending from the undersurface  26  of the flooring plate  20 . In this example, the stop columns  127  extend a shorter distance from the undersurface  26  of the plate  20  than the stiffening columns  22 . As with the stiffening columns  22 , each of the stop columns  127  may be integrally formed with the plate  20 , or may be coupled to the plate  20  as desired. 
     In the illustrated example, both the stiffening columns  22  and the stop columns  127  extend generally perpendicular to the plate  20  and are, in this example, spaced at generally 45° to one another. However, it will be appreciated that the pattern of the columns  22  and  127  may be varied as desired. Furthermore, while the length of each of the stiffening columns  22  and the length of each of the stop columns  127  are illustrated as being substantially similar, respectively, it will be understood that the length of each of the columns  22 ,  127  may vary as desired to provide for different pressure deflection characteristics. 
     As with the previous example, both the stiffening columns  22  and the stop columns  127  are at least partially surrounded by the resilient underlayment  24 . Additionally, the underlayment  24  may be secured to at least a portion of the undersurface  26  of the flooring plate  20  and/or at least a portion of the columns  22 ,  127 . As shown is  FIG. 5 , the resilient underlayment  24  may completely cover any of the columns  127  or may at least partially expose any of the columns  127  when viewed from the underside  26 . 
       FIG. 7  illustrates the example flooring apparatus  100  under the influence of a compressive pressure P i  distributed over the plate  20  under impact conditions. As with the previous example, in this example, the pressure P i  is greater than the predetermined critical pressure (e.g., the pressure at which the columns  22  will buckle). Under these conditions, the plate  20  of the apparatus  100  will deflect toward the support surface  28  and the stiffening columns  22  will deflect to absorb the energy of the impact. The amount of deflection in the plate  20 , however, is limited at a height H L  by contact of the deflection stops columns  127  with the support surface  28 . The columns  22  may, therefore, be the primary means of energy absorption, while the resilient nature of the underlayment  24  provides a secondary means of energy absorption as the floor deforms. The stopping columns  127 , meanwhile, may provide a deflection stop to prevent over-buckling and/or permanent deformation of the columns  22  as well as provide the ability for the flooring apparatus  10  to resume a substantially rigid state after initial deflection to assist, for example, individuals utilizing wheelchairs. After the impact pressure is removed, or otherwise dissipated, the apparatus  10  will return substantially to its original state and the plate  20  will once again be supported at the typical height H above the support surface  28  ( FIG. 5 ). 
     Turning now to  FIG. 8 , an example of an enhanced flooring system  200  is shown. The system  200  includes one of the flooring apparatus  100  and/or  10  (the flooring apparatus  100  is illustrated) including an overlayment  210 . In this example, the overlayment  210  comprises a plurality of tiles  212 , such as traditional floor tiles, and a flexible grout  214 , such as for example, a sand and silicon based grout. Accordingly, the tiles  212  and the grout  214  may deflect with the plate  20 . The overlayment  210  may be any suitable flooring material, including, for example, carpeting, tiling, vinyl, etc. In this example, the tiles  212  width and length of each individual tile is less than the distance between each column  22 . 
     Turning now to  FIG. 8 , an example of an enhanced flooring system  200  is shown. The system  200  includes one of the flooring apparatus  100  and/or  10  (the flooring apparatus  100  is illustrated) including an overlayment  210 . In this example, the overlayment  210  comprises a plurality of tiles  212 , such as traditional floor tiles, and a flexible grout  214 , such as for example, a sand and silicon based grout. Accordingly, the tiles  212  and the grout  214  may deflect with the plate  20 . The overlayment  210  may be any suitable flooring material, including, for example, carpeting, tiling, vinyl, etc. In this example, the tiles  212  width and length of each individual tile is less than the distance between each column  22 . 
     Although certain example methods and apparatus have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.