Patent Description:
Fall-related injuries among the ever-growing North American elderly population are a major health concern. In the United States, nearly <NUM>,<NUM> hip fractures occur per year, more than <NUM>% of which are associated with falls. It is estimated that this number may double or triple by the middle of the century. The repercussions of hip fracture among the elderly add to the concern surrounding the issue. Over <NUM>% of hip fracture patients over <NUM> years of age die within <NUM> year of the injury, and more than <NUM>% suffer major declines in mobility and functional independence.

Traumatic brain injuries (TBI) also make up a significant portion of fall-related injuries; seniors are hospitalized twice as often as the general population for fall-related TBI. The incidence of fall-induced TBI and associated deaths has been rising at alarming rates, increasing by over <NUM>% between <NUM> and <NUM>. The risk for fall-related TBI increases substantially with age; persons over the age of <NUM> are hospitalized for fall-related TBI over twice as often as those aged <NUM>-<NUM>, and over <NUM> times as often as those aged <NUM>-<NUM>.

The financial burden associated with fall-related health care is significant. It is estimated the economic burden of fall-related injuries in Canada approximately $<NUM> billion in annual treatment costs and is expected to rise to about $<NUM> billion by <NUM>.

The costs to treat fall-related injuries in the United States are even higher. The average hospital cost for a fall injury in the US is over $<NUM>,<NUM>, and in <NUM>, costs for falls to Medicare alone totaled over $<NUM> billion.

It would therefore be desirable to implement a surface, such as a flooring, underlayment system that will reduce impact forces and therefore reduce the potential risk of injury associated with fall-related impacts on the surface. Relatedly, it would be advantageous to have a low cost, low profile, durable safety flooring underlayment system that is compatible with sheet vinyl and carpet. Potential benefits include reducing injury risk due to falls on the flooring surface, minimizing system cost, maintaining system durability, facilitating installation, abating noise while offering surface quality and comfort for both patients and caregivers.

Flooring system manufacturers offer a variety of products to the commercial and residential market. These products include ceramic tile, solid wood, wood composites, carpet in rolls, carpet tiles, sheet vinyl, flexible vinyl tiles, rigid vinyl tiles, rubber sheet, rubber tiles, and the like.

Commercial flooring systems are typically installed directly over subfloors comprised of either rigid plywood or concrete. These systems are engineered to either be adhered/affixed directly to the subfloor or to float over the subfloor without being affixed to the subfloor. Products commonly affixed to the subfloor include ceramic tiles, vinyl tiles, sheet vinyl, carpet tiles, rubber tiles, wood flooring, and rubber sheet goods. Products that commonly float over the subflooring system are typically rigid and include luxury vinyl tile, rigid wood composites and plastic flooring tiles.

Further, some flooring constructions add a second layer or underlayment between the subfloor and the flooring system to either increase force distribution, enhance comfort under foot, abate noise within the room and through the flooring, or provide some additional insulation. This second layer can either be affixed to subfloor or float depending upon the recommendation of the system manufacturer.

While such underlayment layers provide some added benefit, they also increase system cost, installation complexity, and often reduce the durability of the top flooring material. To date, no commercially cost effective and durable underlayment system has been developed that provides a substantial injury risk reduction due to falls on the variety of flooring products. Several attempts have been made and are summarized below, but such approaches often fail to meet certain performance and cost effectiveness objectives.

Ecore® is a product manufactured from reconstituted tire rubber particles bound together into roll or sheet goods by a thermosetting polyurethane binder. Similar products are also offered by Cal Rubber and other manufacturers. The crumb rubber is bound using the polyurethane binder and extruded/calendared into sheet or roll stock of a given thickness. The thickness typically ranges from <NUM>-<NUM>. The Ecore rubber layer is adhered to thermally bonded to vinyl sheet flooring product to the rubber. The composite of rubber and vinyl is then bound to the subfloor using a cushioning and comfort under foot, they make sub-optimal contributions to the goals of cushioning a blow that accompanies a fall. The risk and severity of injury due to falls remain.

Smart Cells® is another product that is said to offer fall protection. Such technology was originally developed by Penn State University. The technology involves cylindrical columns of molded thermoset rubber consolidated into a sheet with interconnected ribbing between adjacent columns in a square array. The product is offered in heights of approximately <NUM> and <NUM>. The raw material is compression or injection molded under pressure until the structure crosslinks, to make a stable molded structure.

Installation of this material is labor intensive. Individual squares or rectangles of these molded structures are positioned adjacent to one another during installation. The material is not adhered to the floor. However, a binder adhesive is troweled onto the seams and allowed to cure prior to the application of a pressure sensitive of other bonding adhesive to adhere the final flooring surface to the SmartCells system. Once installed, the seams are prone to separation and read through to the A-surface. Finally, the system is expensive and at a premium that most facilities cannot afford.

Foams of various types have been considered for use in senior living facilities. However, these products are often so soft under foot that they promote instability. This reaction may be significant to someone whose balance may be impaired. Additionally, such structures are prone to compression set due to their cellular nature and do not return to their original shape after sustaining a point static loading for long periods. Such loading may be imposed by a bed, chair, or other heavy object. The entire flooring system is expected to withstand the rigors of daily traffic over these surfaces.

Injection molded tiles that snap into one another are often used for temporary or permanent flooring installations such as stage or dance floors, volleyball, basketball, garages, or other indoor flooring for sport surfaces. While the surfaces maybe acceptable from an appearance standpoint, they offer little force distribution or comfort characteristics. Furthermore, they often contain the moisture on or below the flooring surface. A water-tight system is unacceptable from a healthcare standpoint because there is a tendency for standing water to promote mold propagation, etc. The documents <CIT>, <CIT>, <CIT> and <CIT> were cited,.

<CIT> disclosing the features of the preamble of claim <NUM>.

Against this background, it would be desirable to develop a load distribution and absorption system that would underlay a superstructure material such as flooring system to mitigate injuries and soften footfalls, while reducing noise and vibration where possible.

Ideally, such a system would be of relatively low cost and present a low profile to minimize tripping, yet be durable. In several embodiments, an underlayment infrastructure would be compatible with a superstructure material such as sheet vinyl and carpet.

Among the goals are injury risk reduction due to falls on the flooring surface, minimizing system cost, maintaining system durability, facilitating installation, abating noise, yet retaining surface quality and comfort (in the case of elder care facilities) for patients and caregivers.

To solve one or more of above mentioned problems, present invention provides a load distributing and absorbing tile as defined in claim <NUM>, and a load distributing and absorbing system as defined in claim <NUM> which comprises such a tile.

Accordingly, several embodiments of this disclosure include a load distributing and absorbing system that lies below a superstructure material which is exposed to continual or intermittent percussive forces. Often, such forces may cause a high localized pressure, such as when forces from a wheelchair are exerted via narrow wheels. The load distributing and absorbing system includes an underlayment infrastructure that is interposed between an underside of the superstructure material and a foundation below. In the underlayment infrastructure, load distribution is mainly provided by a barrier layer and load absorption is mainly provided by groups of absorbing members that are provided in tiles thereof (described below).

Most of the absorbing members have a ceiling which is positioned below the barrier layer. A continuous curvilinear wall extends from the ceiling. At the lower portion of the wall is a floor that lies above the foundation.

Tiles are united by inter-engagement of overlapping barrier layers that overlie the ceilings of adjacent tiles.

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention defined by the appended claims that may be embodied in various and alternative forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ alternative embodiments of this disclosure.

<FIG> is a top view of one embodiment of a load distributing and absorbing underlayment system <NUM> that has four quadrilateral, preferably rectangular, tiles <NUM>, <NUM>, <NUM>, <NUM>. These tiles are positioned relative to one another by inter-engaging mating registration features <NUM>, <NUM>, including male <NUM> and female <NUM> features provided along the edges of a barrier layer <NUM>. Each tile <NUM>, <NUM>, <NUM>, <NUM> has an infrastructure <NUM> with a plurality of absorbing members <NUM> for load absorption and a barrier layer <NUM> for load distribution.

Consider <FIG>. The barrier layer <NUM> (in this case) is quadrilateral with edges B1, B2, B3 and B4. A sub-assembly of underlying absorbing members <NUM> includes individual members <NUM> that are conjoined by their ceilings <NUM> which, before for example thermoforming take the form of a planar basal sheet. The absorbing members <NUM> join together and coordinate to form a periphery of the sub-assembly that is quadrilateral and has edges A1, A2, A3 and A4. Each barrier layer <NUM> is securely affixed to one or more of the ceilings <NUM> in a tile. In some cases, the barrier layer <NUM> is affixed to one or more of the ceilings <NUM> by means for securing <NUM> such as an adhesive or by mechanical means including screws, rivets, pins and the like.

Edge B1 of the barrier layer <NUM> overhangs edge A1 of the sub-assembly of absorbing members <NUM> and edge B2 overhangs edge A2. Thus, edges A3 and A4 of the sub-assembly of absorbing members <NUM> extend beyond overlying edges B3 and B4 of the barrier layer <NUM>. This arrangement creates an overhanging L-shaped platform <NUM> (<FIG>, <FIG>) of the barrier layer <NUM> and an open L-shaped roof formed by the ceilings <NUM> of the absorbing members <NUM> in the sub-assembly. In adjacent tiles, the L-shaped roof <NUM> associated with a given tile <NUM> supports the L-shaped platform of the barrier layer <NUM> of an adjacent tile.

One consequence of this arrangement is that adjacent tiles engage each other in such a way as to inhibit relative lateral movement therebetween.

Interlocking engagement of adjacent tiles in a group is provided by mating registration features <NUM>, <NUM> (<FIG>, <FIG>, <FIG>). In a preferred embodiment, these mating registration features <NUM>, <NUM> are trapezoidal in shape. For example, a male trapezoid <NUM> abuts a female trapezoid <NUM> along the edges of adjacent tiles <NUM>, <NUM>, <NUM>, <NUM>. It will be appreciated that there are alternative shapes of mating registration features, such as keyholes, sawtooth, semicircles, jigsaw-like pieces, etc..

<FIG> is a vertical sectional view through two illustrative adjacent abutted tiles, such as <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM> in <FIG>. One version of an underlayment system <NUM> according to the present disclosure includes a barrier layer <NUM> which in some embodiments is in contact with the ceilings <NUM> of hat-shaped absorbing members <NUM>.

As used herein the term "hat-shaped" includes frusto-conical. Such hat-shaped members <NUM> may have a lower portion <NUM> that has a footprint which is circular, oval, elliptical, a cloverleaf, a race track, or some other rounded shape with a curved perimeter. Similarly, for an upper portion <NUM> of an absorbing member <NUM>. As used herein the term "hat-shaped" includes shapes that resemble those embodied in at least these hat styles: a boater/skimmer hat, a bowler/Derby hat, a bucket hat, a cloche hat, a fedora, a fez, a gambler hat, a homburg hat, a kettle brim or up-brim hat, an outback or Aussie hat, a panama hat, a pith helmet, a porkpie hat, a top hat, a steam punk hat, a safari hat or a trilby hat. See, e.g., https://www. hatsunlimited. com/hat-styles-guide.

As used herein the terms "hat-shaped" and "frusto-conical" exclude structures that include a ridge line or crease in a continuous curvilinear wall <NUM> associated with an absorbing member <NUM>, because such features tend to promote stress concentration and lead to probable failure over time when exposed to percussive blows. They tend to concentrate, rather than distribute or absorb incident forces.

Connecting the ceiling <NUM> and the floor <NUM> of an absorbing member <NUM> is a curvilinear wall <NUM>. When viewed laterally, a curvilinear wall <NUM> appears substantially linear or straight before being subjected to an impact force that may reign on a barrier layer <NUM>. When viewed from above or below, the footprint of the lower portion <NUM> or upper portion <NUM> may appear circular, elliptical, oval, a clover leaf, a race-track or some other rounded shape with a curved perimeter.

The floor <NUM> or ceiling <NUM> of an absorbing member <NUM> may be flat or crenelated.

The absorbing members <NUM> may be manufactured from a resilient thermoplastic and be formed into frusto-conical or hat-shaped members <NUM> that protrude from a sheet which before exposure to a forming process is substantially flat.

In one preferred embodiment, the barrier layer <NUM> is made from a strong thin layer of a polycarbonate (PC), the absorbing member <NUM> is made from a resilient thermoplastic polyurethane (TPU), and the means for securing <NUM> is provided by a pressure sensitive adhesive (PSA) which bonds well to both the PC and TPU.

Thus, an underlayment infrastructure <NUM> is created by the juxtaposition of a barrier layer <NUM> and a sub-assembly of absorbing members <NUM>.

An assembly of absorbing members <NUM> and overlying barrier layer <NUM> forms a tile <NUM>, <NUM>, <NUM>, <NUM> (<FIG>). Adjacent tiles are inter-engaged by overlapping and underlapping edges of the barrier layer <NUM> in the manner described above. Preferably, a small, but acceptable, gap exists between barrier layers <NUM> associated with adjacent tiles. The barrier layer <NUM> of one tile overlaps at least some of the exposed absorbing members <NUM> of an adjacent tile.

If desired, an adhesive <NUM> (<FIG>) can be applied to one or both surfaces prior to the application of pressure which then adhesively attaches a barrier layer <NUM> to a tile <NUM>, <NUM>, <NUM>, <NUM>. adjacent tiles. An underlayment infrastructure <NUM> is thus assembled when the edges of adjacent tiles are brought into registration through the inter-engagement of mating registration features <NUM>, <NUM> of adjacent edges of associated barrier layers <NUM>.

While a pressure sensitive adhesive is a preferred embodiment of means for securing <NUM> a barrier layer <NUM> to the ceilings <NUM> of a tile, alternatives for attaching overlapped tiles together through their associated barrier layers <NUM> include mechanical means for attaching such as Velcro®, tape, rivets, etc..

The overlap of the barrier layers <NUM> and proximity of the absorbing members <NUM> on adjacent tiles distributes a load applied to the barrier layer <NUM> over a broad area. Loads are evenly distributed when applied either on a seam between adjacent tiles or within a tile. Loads are at least partially absorbed by flexure and possible rebound of the walls in the absorbing members.

<FIG> and <FIG> depict a representative assembled flooring system which includes the underlayment infrastructure <NUM> and three superstructure materials <NUM>, such as flooring products. Those figures depict a section through a typical carpet system (<FIG>), a sheet vinyl or rubber system (<FIG>), and rigid wood or composite tiles (<FIG>). Commercial carpet systems are most often bonded directly to a foundation <NUM> or subfloor or to an underlayment material using an adhesive. Sheet vinyl or rubber are typically adhesively bonded to the underlayment material. The rigid wood or composite tiles may or may not be adhesively bonded to the underlayment material, depending on the product recommendations.

<FIG> and <FIG> show two different tile orientations. <FIG> shows a four-tile arrangement <NUM>, <NUM>, <NUM>, <NUM> where adjacent tiles lie in the same orientation. This orientation is preferred as it minimizes the number of edge cuts when the installation site is rectangular. <FIG> suggests a three-seam intersection or staggered configuration of adjacent tiles. The periodicity of the male <NUM> and female features <NUM> in the barrier layer <NUM> are engineered such that the tiles can be staggered relative to one another to create a "T" seam (<FIG>) as opposed to a seam in the four-tile intersection (<FIG>). Both configurations contemplate overlapping the barrier layer <NUM> of one tile with another (see also, e.g., <FIG>).

It will be appreciated that in some applications, a given sub-assembly <NUM> absorbing members <NUM> may have more than one overlying barrier layer <NUM>.

A preferred embodiment of the finished tiles is a <NUM> ft x <NUM> ft rectangular tile. Tiles of this size can be delivered to the job site on densely packed pallets. They fit through any doorway. Alternatively, any number of polygonal arrangements of tiles including hexagons and the like could form a load distribution and absorbing system <NUM>. However, the four-sided structures are preferred to conform with rectangular rooms.

Flooring systems are rarely uniformly dimensioned or shaped throughout a facility. Flooring transitions from one product to another often require a transition feature <NUM> (<FIG>, <FIG>) to smoothly graduate from one height and type of product to a product of another type and height. In some cases, sheet vinyl flooring is usually around <NUM> in thickness. But rigid products can be as high as <NUM> or <NUM>. Commercial carpet often lies somewhere in between sheet vinyl and rigid.

<FIG> shows an illustrative engineered height transition <NUM> that transitions from an <NUM> safety flooring system to another flooring product that is lower in height. The transition from <NUM> to <NUM> over a length of approximately <NUM> meets the Americans with Disabilities Act (ADA) requirements for wheelchairs.

<FIG> is a cross sectional view of one transition feature <NUM> overlapping an adjacent tile. In such cases, the transition has a barrier layer <NUM> extending across the tiles which overlaps adjacent sub-assemblies <NUM> of absorbing members <NUM> and provides a sloped section <NUM> (<FIG>) to transition down to an alternative construction. While the transition feature <NUM> could be positioned almost anywhere within a flooring surface, these transitions would often occur near a doorway from one room to the next. For example, a facility may choose to deploy carpet and underlayment in a patient room for comfort and sheet vinyl with no underlayment in a hallway. The transition feature <NUM> can be cut where the height matches the height of the adjacent flooring system.

In alternative embodiments, mating registration features <NUM>, <NUM> may resemble jigsaw puzzle pieces or rectangles. Overlap of a barrier layer over an adj acent tile of absorbing members is facilitated by a tight gap between adjacent tiles. This feature helps avoid soft spots or read through defects in form and appearance. <FIG> represents one alternative interlock design.

The absorbing members <NUM> may be made from various materials. In a preferred example, they may be thermoformed from a resilient thermoplastic polyurethane from a <NUM> to <NUM> base stock. Such units may have a curvilinear wall <NUM> with <NUM> to <NUM> degrees of draft and be <NUM>-<NUM> in height. Such constructions are primarily suitable for commercial applications.

Other environments of deployment, such as residential, may require less durability and resiliency since they experience relatively little wear. In such cases, the absorbing members <NUM> or the barrier layer <NUM> could be produced from other less resilient and less expensive thermoplastics such polyethylene, polypropylene, acrylonitrile butadiene styrene, polycarbonate and the like. Residential applications may require less durability and resiliency since they experience only a fraction of the force distribution. Additionally, a casting or injection molding process could also be deployed to produce a similar product or structure.

For commercial applications, barrier layer materials <NUM> are preferably made of polycarbonate between <NUM> and <NUM> in thickness with a surface texture.

Alternative approaches to affixing the superstructure material <NUM> to the barrier layer <NUM> or the barrier layer to the ceiling <NUM> of an absorbing member <NUM> through means for securing <NUM> will now be described. Styrene butadiene rubber and polypropylene-based pressure sensitive adhesive, like HB Fuller <NUM>, is preferred over other adhesive types based on its affinity for both PC and TPU layers. Pressure sensitive adhesive is preferred over other types of adhesive systems as it allows for adjacent tiles to be adhered to one another with a pre-applied adhesive that requires only pressure to activate. Unlike rigid thermosetting adhesive systems, the PSA remains pliable over the life of the system. However, other adhesives could be utilized to permanently or temporarily bond the layers together. The HB Fuller adhesive preferred is specific to the materials of construction and an alternative might be better suited to a different build of materials.

Other applications for the disclosed load distributing and absorbing system <NUM> exist. It will be appreciated that this disclosure is mainly focused on fall protection for older adults or infirm patients in areas where slips and falls are prone to occur. However, it is conceivable that the system could be used in other applications or environments of use beyond fall protection. As non-limiting examples, these include work mats, blast mats, boat matting, work platforms, anti-fatigue mats, enhanced comfort mats, wall protection, playgrounds, day care floors, residences, sports surfaces, and other surfaces where those in contact with the surface might benefit from the technology.

The system <NUM> can be enhanced by further layers that provide an added function. The barrier layer <NUM> may include an additional layer of PSA film for the attachment of a superstructure material <NUM> such as a flooring surface or an additional sound abatement layer such as rubber, cork, vinyl barrier, and insulators. The absorbing members <NUM> may also have additional layers for sound abatement or adhesive.

In some cases, the load distributing and absorbing system <NUM> may benefit from the addition of a barrier layer <NUM> where no adjacent tile exists, and the PSA is exposed on a tile edge as in <FIG>. Adding these pieces would be most logical starting from a wall edge so that the first piece does not need to be trimmed back and a full tile can be installed without trimming.

Advantages of the disclosed load distributing and absorbing system include:.

Testing has demonstrated that use of various embodiments of the disclosed system may lead to a:.

Test data indicate that the proposed load distributing and absorbing systems have the potential to substantially reduce the risk of injury and improve the quality of life for both older adults and caregivers.

Claim 1:
A load distributing and absorbing tile (<NUM>, <NUM>, <NUM>, <NUM>) that is adapted to be used in a load distributing and absorbing system (<NUM>) that lies below a superstructure material (<NUM>) which is exposed to percussive forces, the load distributing and absorbing infrastructure tile (<NUM>, <NUM>, <NUM>, <NUM>) being adapted to be interposed between the superstructure material (<NUM>) and a foundation (<NUM>) below, the load distributing and absorbing infrastructure tile (<NUM>, <NUM>, <NUM>, <NUM>) having an infrastructure (<NUM>) underlaying the superstructure material (<NUM>) and comprising:
a barrier layer (<NUM>) adapted for distributing at least some of the percussive forces that lies below the superstructure material (<NUM>), the barrier layer (<NUM>) being quadrilateral with edges B1, B2, B3 and B4, the edges B1 and B2 including female trapezoidal registration features, and the edges B3 and B4 including male trapezoidal registration features;
an absorbing member (<NUM>) adapted for absorbing at least some of the percussive forces that is adapted to be positioned below the barrier layer (<NUM>), the absorbing member (<NUM>) being quadrilateral and having edges A1, A2, A3 and A4, the absorbing member including hat-shaped energy absorbing member (<NUM>), at least some of the hat-shaped energy absorbing member (<NUM>) having:
a ceiling (<NUM>), the ceiling (<NUM>) being adapted to be positioned below the barrier layer (<NUM>);
a curvilinear wall extending from the ceiling (<NUM>), the curvilinear wall having a lower portion; and
a floor (<NUM>) that connects facing sections of the curvilinear wall of adj acent hat-shaped energy absorbing units, the floor (<NUM>) being adapted for lying above the foundation (<NUM>), characterized in that:
the barrier layer (<NUM>) is secured to an absorbing member (<NUM>) so that:
edge B1 of the barrier layer (<NUM>) overhangs edge A1 of the absorbing member (<NUM>) and edge B2 overhangs edge A2, and
edges A4 and A3 of the absorbing member (<NUM>) extend beyond edges B4 and B3 of the barrier layer (<NUM>), thereby creating an L-shaped platform and an L-shaped roof that engage corresponding male and female trapezoidal registration features of adjacent infrastructure tiles.