Abstract:
A flexible interlocking floor tile having a dual construction with an interlocking mechanism allows for easy installation of multiple tiles. The dual construction can include recycled material and new material. The tile also includes an adequate support at the corner of the tile when assembling multiple tiles. The tile has a single interlocking structure or groove to keep the entire tile joint tight with other tile joints, instead of interrupted interlocking structure which can lead to functional and aesthetic flaws in the entire floor. The single continuous interlocking structure allows for a one-step easy removal of any excess material or flashing from the tile after the molding process.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to floor tiles, and is directed in particular to a flexible interlocking floor tile made from rubber, vinyl, polyvinyl chloride (PVC), plastic or the like. More particularly, the invention relates to interlocking floor tiles which can be easily manufactured and installed without the need of a professional installer. 
     2. Description of the Prior Art 
     Various types of commercial flooring are known in the art. Such places which utilize commercial flooring are usually high traffic areas and include office buildings, hospitals, recreation centers, etc. These high traffic areas require durable yet inexpensive flooring with aesthetic appeal as well. Traditional wood flooring is expensive and difficult to maintain and is not ideal for commercial use. Hard laminate flooring is an alternative to wood flooring but is also expensive. Carpet is not usually desired in high traffic areas since it will wear very quickly, is difficult to clean and must be replaced often, and may impede the travel of vehicles thereacross. Even if the above types of flooring are chosen for commercial use, they require significant time and effort to properly install. If a new building is being constructed, construction may be delayed based on the time it takes for installation of any of the above flooring. Furthermore, removing and replacing any of the above floor types is also expensive and time consuming, which may cause delays in actual operation of the business inside the building. Some such removal and replacement is at times done at night or on weekends so as not to obstruct traffic where such activities are being done. 
     Based on the above shortcomings of the various flooring mentioned, cheaper yet durable flooring made from rubber, vinyl and the like has been used for commercial settings. Such flooring usually comprises individual molded tiles, panels, boards etc. which interlock together and are placed over a subfloor. Various types of interlocking mechanisms are known in the art. For example, Johnsonite Inc. of Chagrin Falls, Ohio has manufactured an interlock tile under the name UNDERLOCK®. The UNDERLOCK® tile features an interlocking mechanism in the form of a dovetail connection on the underside of the tile which fit together like a puzzle without the need for an adhesive either between the respective tiles, or between the tiles and the floor or subfloor. These UNDERLOCK® tiles are easy to install and uninstall and can be done without a professional installer. 
     One drawback with most molded products is the presence of flashing that is left behind on the product after the molding process. Flashing is excess material in a thin layer exceeding normal part geometry of the product. The flashing extends from a molded product, and must usually be removed. Flashing is typically caused by leakage of the molding material between the two surfaces of a die or mold that actually leaks out of the mold. With respect to interlocking flooring assemblies, flashing must be removed in order to ensure a precise interlocking fit between the tiles. Any excessive flashing which is not removed from the interlocking tiles may compromise the integrity of the mating of the tiles, which could lead to uneven flooring, curling and peaking etc., and also may add difficulty to the installation of such tiles. The flashing is typically removed by the installer during the installation process. The installer uses a utility knife or other tool to cut away and remove the excessive flashing. Since removal of the flashing is another time consuming step for the installer, a quick and easy method for such removal is desired. Flash removal is particularly time consuming for tiles having intersecting edges, since the installer cannot simple move the utility knife along a straight line, but rather would have to change the direction of movement often. Since flash removal must be done for each tile, the amount of installation time is greatly increased. If the excess flashing is removed by the manufacturer before installation, additional time and expense is still required for this tedious process. 
     Additionally, some tiles feature a studded partial backing to keep the tiles raised above the subfloor while providing air space between the studs. Such studs allow less contact with the subfloor in the event contaminants and liquids are present. However, the studs extend only over the dovetail configuration or interlocking mechanism and do not cover the entire bottom of this type of tile. The dovetail configuration is often an important feature of this type of tile. 
     U.S. Publication No. 2005/0183370 to Cripps discloses a floor tile with interlocking edge elements that enable juxtaposed tiles to be assembled by a vertical snap or press-in assembly method to secure tiles together. A first and second pair of contiguous lateral extension walls of the tile are arranged to meet at a square corner of approximately ninety degrees and lie at opposite edges of the tile from the first two lateral extension walls. The second lateral extension walls meet at a common corner that is diagonally opposite from another corner. The floor tile has two channels as a result of first and second lateral extension walls which form part of the interlocking mechanism. The sidewalls forming the channels include an undercut as part of the interlocking mechanism. The tile does not include a downwardly extending member at the corner of the tile for additional support at the corner of tile. The floor tile is made from a unitary material rather than a dual construction made of two materials. 
     U.S. Publication No. 2007/0011980 to Stegner et al. discloses a unitary interlocking floor tile with interlocks located on adjacent sides of the tile having a gap located at a mid point of the interlocks along each side of the tile, creating a discontinuous interlocking structure on the sides of the tile. The interlocking structure does not fully extend to the corner of the tile. Stegner et al. does not teach a continuous interlocking structure on adjacent sides of a tile extending to the corner of the tile. The discontinuous interlocking structure of Stegner et al. leads to multiple joints when interconnecting the tiles, which can result in a loose fit amongst the tiles, creating both functional and aesthetic problems. If the discontinuous interlocking structure is not a completely straight line between the gap, realignment problems can occur when fitting multiple tiles together, especially if the tiles are staggered and not side by side. The discontinuous locking structure also results in an excessive amount of time required to remove the flashing from the interlocking structure as well as requiring additional time for the installer to remove such flashing, since the direction for the utility knife to move must be interrupted on different sides of the tile. This is due to the gap located at a mid-point of the interlocks along each side of the tile, wherefore the installer cannot remove the flashing in a single motion using a utility knife. 
     U.S. Publication No. 2003/0093964 to Bushey et al. discloses a floor grid system including a number of interconnectable tiles made from a single unitary material. The tiles are interconnected with one another through the use of locking assemblies extending between the tiles. The locking assembly uses half dove tails as the interlocking configuration. The upper face of the tile includes two locking elements on two adjacent sides of the upper face of the tile. The bottom face of the tile includes two locking elements on the opposite adjacent sides of the bottom face of the tile. Each locking element includes a base projecting outwardly from the tile and an upwardly extending vertical member having an inner surface spaced from a corresponding side of the tile so as to define a wall receiving channel therebetween. The locking elements on adjacent sides of the tile extend beyond the corner of the tile, with a vertical protrusion located that the intersection of the locking elements. Bushey et al. does not include a downwardly extending member at the corner of the tile. Furthermore, the locking elements have numerous edges in difficult directions causing a large amount of time for flash removal. 
     Accordingly, there is a need for a tile with an interlocking mechanism which is partly spaced from the floor or subfloor and possible contaminants on the floor or subfloor when installed. Such a tile should be easy to manufacture and allow for some misalignment of seams of the tile to allow for different layout designs and for multiple size tiles to be fitted together, which does not detract from the aesthetics of the tiles when laid or from their functionality. There is also a need for a tile which reduces the amount of flashing to be removed, and which is easier to install and re-install than existing tiles, saving installation time. Desirably, such a tile would allow for a continuous connection along all of the sides of the tile and include adequate support at the corner of the tile. The latter feature would prevent bending or buckling of the corners of overlapping tile portions, as when a high heel shoe is pressed thereon. The desired tile would have a single interlocking structure or groove to keep the entire tile joint tight with other tile joints, instead of interrupted interlocking structure which could lead to functional and aesthetic flaws in the entire floor. The single continuous interlocking structure would allow for a one-step easy removal of any excess material or flashing from the tile after the molding process. The tile would desirably include a continuous uniform distribution of shallow studs on the entire bottom of the tile to allow for the wicking of moisture and prevention of exposure of the interlocking mechanism to contaminants from the subfloor. Most desirably, such a unit maintains a strong, structurally sound mounting of the tile on the floor which allows for easy installation. Time saving is particularly important in multiple room facilities where flooring needs to be installed quickly and cost efficiently such as for apartment buildings, hospitals, hotels and the like, where new building construction and renovations are common. Thus, the problem to be solved by the present invention is to provide a tile with the above characteristics. 
     Many floor tiles are made entirely of relatively expensive vinyl or artificial rubber. This can be expensive, particularly for commercial buildings with extensive floor space to be covered with the tile. It would be advantageous to employ less expensive recycled vinyl, artificial rubber or the like on part of the underside of the tile where it is not visible after it is laid, yet serves its intended purpose and has all of the necessary structural features. 
     SUMMARY OF THE INVENTION 
     The present invention provides a flooring solution to the above-described problems of producing and installing interlocking floor tiles. Applications of the interlocking floor tile according to the present invention may include covering access floors, temporary office quarters, workout areas, subfloors with high moisture content or even trade show floors—areas where performance and flexibility are equally important. The interlocking floor tiles are designed to fit together without the locking structure underneath the respective tiles being readily observable, and if observed being nevertheless aesthetic. Damaged tiles can be easily removed according to the preferred embodiment of the invention as discussed below, even in the middle of the floor and replaced, without any special tools required; removal and replacement are accomplished as discussed below, by simply pulling up the damaged tile and replacing it. 
     It is an object of the present invention is to provide an interlocking floor tile that can be easily installed and re-installed without necessarily requiring a skilled installer. 
     It is also an object of the present invention to provide an interlocking floor tile which could be installed using a hand seam roller to locking the respective tiles together. 
     Another object of the present invention is to provide an interlocking floor tile having a continuous connection along all of the sides to keep the entire joint tight between the tiles. 
     Still another object of the present invention is to provide a tile with adequate support at the corner of an installed set of tiles. 
     A further object of the present invention is to provide an interlocking floor tile with an interlocking mechanism which is not completely and directly exposed to the subfloor and any contaminants thereon. 
     It is a further object of the present invention is to provide an interlocking floor tile which does not require an adhesive for installation either between the respective tiles or between the tiles and the floor or subfloor. 
     Still another object of the present invention is to provide an interlocking floor tile which is portable and can be used for both temporary and permanent installations. 
     Another object of the present invention is to provide an interlocking floor tile which can be placed directly over uncured concrete slabs. 
     A still additional object is to provide an improved interlocking floor tile system that can be installed on subfloors with high moisture content. 
     A further object of the present invention is to reduce significant installation time and the associated expense with flooring installation techniques making it easier to lay the inventive tiles as compared to laying existing tiles, and by reducing flashing that must be removed and the overall time required for installation. 
     Yet another object of the present invention is to provide an interlocking floor tile which can be easily removed due to damage or other problems and replaced without any special tools. 
     Another object of the present invention is to provide an interlocking floor tile having a dual construction and comprises in part non-observable recycled artificial rubber or other material having a lower cost than the visible portion of the tile. 
     Still another object of the present invention is to reduce the weight of the tile without reducing the functions of the tile or the area of coverage of each tile, by incorporating shallow studs on the bottom of the entire tile, which would additionally make the improved tile easier to install, remove and \transport. 
     Yet another object of the present invention is to provide an interlocking floor tile which is slip resistant. 
     It is yet still another object of the invention to provide an improved interlocking floor tile which can be easily maintained. 
     A further object of the present invention is to provide an interlocking floor tile which is fire resistant and has a Class 1 Flame Rating. 
     Another object of the present invention is to provide an interlocking floor tile that can accommodate various size tiles to create unique and aesthetic patterns. 
     It is also an object of the present invention to provide an improved interlocking floor tile having the advantages noted above which can be laid in a traditional corner-to-corner pattern or offset to create a staggered look. 
     It is a general object of the invention to provide an improved tile which is effective in its production, installation and use, and which can be manufactured efficiently and economically. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other characteristics and advantages of the present invention will emerge from reading the detailed description hereinbelow of nonlimiting embodiments of the invention, and examining the attached drawings wherein: 
         FIG. 1A  is a top perspective view of the interlocking floor tile according to the present invention. 
         FIG. 1B  is a top perspective view of the tile of  FIG. 1  shown from another angle of the tile. 
         FIGS. 2A-2C  are enlarged partial top perspective views of several corners of the tile of  FIG. 1 . 
         FIG. 3A  is a partial side view of a corner of one of the sides of the tile of  FIG. 1 . 
         FIG. 3B  is a partial side view of a corner of another of the sides of the tile of  FIG. 1 . 
         FIG. 4A  is a bottom perspective view of the tile of  FIG. 1 . 
         FIG. 4B  is bottom perspective view of the tile of  FIG. 1  shown from another side of the tile. 
         FIGS. 5A-5D  are enlarged partial bottom perspective views of several corners of the tile of  FIG. 1 . 
         FIG. 6A  is another enlarged partial bottom perspective view of another corner of the tile of  FIG. 1 . 
         FIG. 6B  is a partial side view of a corner of still another side of the tile of  FIG. 1 . 
         FIG. 7A  is a top partial perspective view of two adjacent tiles before assembly. 
         FIG. 7B  is a top partial perspective view of two adjacent tiles after assembly. 
         FIG. 7C  is a top partial perspective view of three adjacent tiles before assembly. 
         FIG. 8A  is a bottom partial perspective view of three adjacent tiles before assembly. 
         FIG. 8B  is a bottom partial perspective view of three adjacent tiles after assembly. 
         FIG. 9  is a top perspective view of multiple staggered tiles after assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiment of the present invention relates to an improved floor tile with an interlocking mechanism which is easy to be laid with a quality installation. The installed inventive floor tile is not completely and directly exposed to the subfloor and any contaminants thereof. The interlocking floor tile can be formed of any suitable flexible material, such as plastic, vinyl or rubber (including artificial rubber), among others. As recited herein, a flexible tile is defined as a tile which is made from plastic, vinyl, polyvinyl chloride (PVC) or rubber. The tiles are not limited to a specific size but can be designed in any size to accommodate the size of the subfloor or floor and the space to be covered. The tile is preferably composed of an attractive exposed material when installed, with low cost but effective inexpensive material which is not exposed when the tile is installed. The inventive tile can be placed on a floor or subfloor, slid relative to adjacent tiles to the desired position, and pressed together with the adjacent tile to interlock them together. Preferably no adhesive is required to install tiles according to the invention. 
     Turning now to  FIGS. 1A ,  1 B and  4 A,  4 B, illustrated is an example interlocking floor tile  10  according to the preferred embodiment of the present invention. Each tile  10  is preferably made of dual construction, meaning each tile  10  includes a top portion  12  made from one material and a bottom portion  14  except for its edge portions, made from another material. Both layers have rubber components. More than two different materials could be also be used. In a preferred embodiment, flexible interlocking floor tile  10  is composed of 73% recycled rubber and 27% new rubber. Top portion  12  includes a large top layer  112  which is a finish layer for aesthetics and performance, and can be made from any number of materials known in the art capable of being flexible and resilient to absorb shock and returned if momentarily bent or indented, to its original shape. For example, top layer  112  could be made from rubber, which has a greater elastic effect. Top layer  112  may include a number of different components for performance, such as SBR rubber and clay. SBR (styrene-butadiene-rubber) is a synthetic rubber copolymer consisting of styrene and butadiene. Top layer  112  may also include pigments and/or a design for aesthetic purposes. As discussed below, the harder material of top layer  112  is also used for the edge of top portion  12  and part of the edge of bottom portion  14 . According to a preferred embodiment, bottom portion  14  is 7.5 mm in height and top portion  12  is 2.0 mm in height. 
     Bottom portion  14  includes large base layer  100  of less expensive, preferably softer material such as recycled rubber discussed below. Large base layer  100  extends to a very edge  102  of tile  10  on two sides, only up to a pair of channels discussed below at edges  104  and  106  of large base layer  100 , and to an edge  108  shown as a line, all depicted in  FIGS. 4A ,  4 B. Base layer  100  provides padding and absorbs some of the shock from loads on tile  10 . Base layer  100  can be made from a cheaper material than top layer  112 . For example, base layer  100  can be made from industrial rubber scrap or recycled rubber including recycled SBR rubber. New SBR rubber, natural rubber and vulcanized recycled rubber dust may also be used. 
     Top portion  12  and bottom portion  14  are combined together to form a dual construction tile by vulcanization, which is well known in the art. Top portion  12  comprises a sheet of rubber as defined above while bottom portion  14  includes a sheet of recycled rubber as previously mentioned. The respective sheets are stacked on top of each other and put into a mold in a press, i.e. top portion  12  is stacked on top of bottom portion  14 . The two sheets are then bonded by the vulcanization process without the use of a bonding agent. It is possible that during the vulcanization process that the two different sheets of different material may overflow into either top portion  12  or bottom portion  14 . 
     Each tile  10  can have any desired polygonal shape, but is preferably generally rectangular in shape for ease of interlockability. For tiles having any polygonal shape, a side portion of a first tile will have a specific shape while a side portion of another tile adjacent the side portion the first tile will have a corresponding mating shape. It is also possible for a single tile to have a side portion having a specific shape while a side portion opposite of the first side portion of the tile has a corresponding mating shape. For example, if the tile is in the shape of a crescent moon, a side portion of this tile will have a convex shape, while the shape of a side portion of another crescent moon-shaped tile adjacent the side portion of the first tile will be concave. Thus, the respective side portions have corresponding mating shapes. 
     As shown in  FIGS. 1A ,  1 B, top layer  112  includes outwardly-facing top planar sidewalls  15  on each of two adjacent side portions  11   a ,  11   b  of tile  10 . A bottom interlocking element set  16  is included in top portion  12 , is separated from top layer  112  and is located adjacent outwardly-facing top planar sidewall  15  on each of two adjacent side portions  11   a ,  11   b  of tile  10 . Referring to  FIGS. 2A-3C , bottom interlocking element set  16  includes a bottom base  18  and a bottom upwardly extending male locking projection  20 . Bottom base  18  extends outwardly from outwardly-facing top planar sidewall  15  near bottom portion  14  of tile  10 . Bottom upwardly extending male locking projection  20  has an inwardly-facing bottom planar wall  22  spaced from outwardly-facing top planar sidewall  15  of corresponding side portions  11   a ,  11   b  of tile  10  so as to define a bottom channel  24  therebetween. Bottom interlocking element sets  16  are made from a dual construction, i.e. they are composed of both material from top portion  12  and of material from bottom portion  14 . 
     Respective bottom interlocking element sets  16  on respective adjacent side portions  11   a ,  11   b  are connected by a bottom base element  25  at a corner  27  of tile  10 . A bottom base element  25  is an extension of bottom base  18  but is devoid of any male locking portion projecting therefrom. Bottom base element  25  provides support for a corner post of an adjacent interlocking floor tile  10  when joined together as further explained below. 
     When viewed from the bottom, shown in  FIGS. 4A ,  4 B, base layer  100  includes outwardly-facing bottom planar sidewalls  17  on each of the other two adjacent side portions  1  ic,  11   d  opposite from side portions  11   a ,  11   b  on top portion  12  of tile  10 . Each adjacent side portion  11   c ,  11   d  includes a top interlocking element set  26 . Referring to  FIGS. 5A-6B , top interlocking element set  26  includes a top base  28  and a top male downwardly extending (when bottom portion  14  is facing downwardly) locking projection  30 . Top base  28  projects outwardly from each outwardly-facing bottom planar sidewall  17  of respective side portions  11   e ,  11   d  near the top of tile  10  and top downwardly-extending male locking projection  30  extends downwardly from top base  28 . Top downwardly-extending male locking projection  30  has an inner wall  32  ( FIG. 5A ) spaced from sidewall  17  of a corresponding side  11   c ,  11   d  of tile  10  so as to define a top channel  34  therebetween. 
     As shown in  FIGS. 5C-5D , respective top interlocking element set  26  on respective adjacent side portions  11   c ,  11   d  are connected by a top base element  35  at an upper corner  37  of tile  10 , top base element  35  being an extension of top base  28 . Top base element  35  is substantially the same thickness as top base  28  (i.e., top base element  35  is level with top base  228 ) and includes a support post  38 . Support post  38  depends downwardly from top base element  35  towards the subfloor when tile  10  is installed. Support post  38  provides support in conjunction with bottom base element  25  upon which it is seated near the corner of an adjacent tile  10  when joined together as shown from the bottom of multiple tiles  10  being joined together in  FIG. 8A .  FIG. 8B  shows multiple tiles  10  joined together from  FIG. 8A , but support post  38  is hidden from view. Bottom base element  25  on top portion  12  does not have any male projections in order to allow clearance for top male locking element set  26  to pass therethrough when multiple tiles  10  are joined together. When multiple tiles  10  are joined and respective top locking element set  26  and respective bottom locking element set  16  are connected, a void would be created if support post  38  did not exist. Such a void would create tripping hazard since top base element  35  would not be supported at its upper corner  37  when tile  10  is installed, and would be depressed or deformed by a stiletto, cleat, ice skate or other shoe with a pointed structure on the bottom of the shoe. However, support post  38  fills the void and fully supports the corner of tile  10 . It is advantageous that support post  38  projects downwardly from top base element  35  rather than being located on bottom base element  25  and projecting upwardly. When depressed by a shoe (or part of a shoe such as a stiletto heel etc.), support post  38  effectively prevents any movement of upper corner  37  (such as sliding or shearing) with bottom base element  25  of another tile  10 . However, if support post  38  was located on bottom base element  25 , there is believed to be a greater likelihood that upper corner  37  could slide or shear on support post  38  since support post  38  is not connected to upper corner  37  when depressed by shoe (or part of a shoe such as a stiletto heel etc.). This could cause tripping and possible injury to the person walking (or running) on tile  10 . 
     In a preferred embodiment, the male locking projections  20  and  30  on the corresponding interlocking element sets  16  and  26 , respectively, have a generally square-shaped cross-section as shown in  FIGS. 3A ,  3 B and  6 B, for reasons hereinafter described. However, the cross-section can include some type of dove-shaped designs as well. 
     Considering  FIGS. 2A-2C  and  3 A- 3 B, the upper edges of each tile  10  are slightly curved or canted as shown at numeral  29 . Since when installed the respective tiles  10  may not be in the same plane at their upper surface, one would not want any tile to jut upwardly even if it not be so high as to cause possible tripping when walking thereacross, so as to spoil the smooth appearance. Therefore, curves or cants  29  may be visible, but are not unsightly, which would add aesthetic appeal to the floor as shown in  FIGS. 7A-7C . The appearance might be particularly noticeable early or late in the day when sunlight strikes the floor at a very small angle, but would not be visually unpleasant to observe. 
     Since the present invention is manufactured from molding methods well known in the art, flashing is likely to remain on certain areas of tile  10  as previously discussed. Flashing occurs during the molding process, where rubber or other material oozes along the edges of the mold which leaves excess material (i.e. flashing) after the tile cures. Flashing normally occurs at various edges of tile  10 , including the respective interlocking element sets  16  and  26 . This excess flashing must usually be removed in order for tiles  10  to be able to lock together. A utility knife or other suitable tool is used to trim the excess flashing. Since the interlocking element sets  16  and  26  run the full length of tile  10  without interruption, excess flashing is easily removed with a utility knife using one continuous motion. There are no curves or sharp corner edges (i.e. puzzle pieces) that need to be traced and subsequently trimmed with the utility knife. This greatly reduces installation time. 
     There are additional advantages of the present invention based on the continuous connection along all sides of tile  10  since there is no interruption in respective interlocking element sets  16  and  26 . Tiles could be locked together with a commonly used hand seam roller. This allows the connection or joint where two tiles  10  meet to remain tight, which will provide a better appearance and prevent dirt and other debris and even possibly moisture from entering the joint. This could be done with a commonly used hand seam roller. Another advantage of the continuous connection or joint is the prevention of realignment problems with tiles  10 . As previously mentioned with respect to the prior art, individual locking tabs or a discontinuous locking connection will result in possible realignment problems. Finally, since the interlocking element sets  16  and  26  run the full length of tile  10  without interruption, the tiles  10  can be staggered to form any type of pattern or design (i.e. tiles  10  do not need to be corner to corner). For example,  FIG. 9  shows a number of tiles in a staggered pattern. 
     In order to maintain a tight joint as discussed above, the interlocking element sets  16  and  26  have a generally square-shaped cross-section as shown in  FIGS. 3A ,  3 B and  6 B. Respective male locking projections  20  and  30  are press fit into respective bottom and top channels  24  and  34 , respectively, easily done with a hand seam roller. Since tile  10  is flexible, there is some elasticity when male locking projections  20  and  30  are fit into top and bottom channels  24  and  34 . However, an initial force must be overcome to begin the press fit of tiles  10  together. In order to help overcome this initial force, interlocking element sets  16  and  26  include rounded and/or chamfered edges and corners in order to provide a small space or relief to overcome the initial force. Top downwardly-extending male locking projection  30  includes rounded corners  40  as shown in  FIG. 5A . Top locking element set  26  in bottom portion  14  additionally has a chamfered edge  42  which runs along an inside edge  44  of top male locking projection  30  as shown in  FIGS. 5A-5D  and  6 A,  6 B. Support post  38  also includes rounded edges  46 . Rounded corners  40 , chamfered edge  42  and rounded edges  46  provide a small space or relief when top downwardly-extending male locking projection  30  is initially press fit into respective bottom channels  24 . This space or relief is especially necessary in case any excess flashing remains on interlocking element sets  16  and  26 . For example, if a small piece of flashing remains on bottom upwardly-extending male locking projection  20 , chamfered edge  42  of top male locking projection  30  will provide space or relief for the flashing and will allow top downwardly-extending male locking projection  30  to be fit into bottom channel  24 . Even if no excess flashing exists, chamfered edge  42  will allow top upwardly-extending male locking projection  30  to enter into bottom channel  24  and overcome the initial force of fitting and locking tiles  10  together. 
     In order to interlock tiles  10  together, a pair of tiles  10  are positioned adjacent each other as shown in  FIG. 7A , but may also be staggered as mentioned above and shown in  FIG. 9 . Top male locking projection  30  of top interlocking element set  16  is inserted into bottom channel  24  of adjacent tile  10 . Rounded corners  40 , chamfered edge  42  and rounded edges  46  provide a small space or relief when top downwardly-extending male locking projection  30  is initially press fit into respective bottom channels  24 . Bottom upwardly-extending male locking projection  20  is then inserted into top channel  34  of top interlocking element set  26 . The square cross-section configuration of male locking projections  20  and  30  maintain the connection between adjacent tiles  10  and prevent lateral movement of tiles  10  when placed on top of a subfloor as shown in  FIG. 7B . Since tile  10  is flexible, respective interlocking element sets  16  and  26  can slightly deform when engaged with one another to secure tiles together and provide a tight joint.  FIG. 7C  shows multiple tiles  10  being joined together. 
     Bottom portion  14  includes a continuous grid of shallow flat round studs  50  that flow uninterrupted into adjacent tiles  10  when installed as shown in  FIG. 8B . Studs  50  may provide moisture flow when uncured concrete (or moist subflooring) is still drying, and more cushioning effect for tile  10  when a load is imposed thereon such as when tiles  10  are walked upon, vehicles are transported across, cleaning and repair equipment are disposed thereon or the like. The use of studs  50  provide less contact with the subfloor. If the subfloor has old adhesive or contaminants, it will be easier to pull up, if needed. Thus, studs  50  are easier to disengage from a floor or subfloor, facilitating installation and removal of particular tiles  10 . 
     In addition to being made at least partially from recycled material the interlocking floor tile of the present invention also includes other beneficial characteristics. For example, the interlocking floor tile is fire resistant and has a Class 1 Flame Rating. 
     Tiles according to the present invention can be easily maintained by using a damp mop or microfiber pad along with a minimal amount of water and cleaning solution. This maintenance technique avoids water migrating to the subfloor through the hidden locking mechanism. 
     Although the invention has been described with regard to certain preferred example embodiments, it is to be understood that the present disclosure has been made by way of example only, and the improvements, changes and modifications in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. Such improvements, changes and modifications within the skill of the art are intended to be covered by the scope of the present disclosure.