Patent Publication Number: US-8528278-B2

Title: Embedment tile with replaceable top plate

Description:
This is a continuation of U.S. application Ser. No. 12/462,398 filed Aug. 3, 2009, which is a continuation-in-part of pending U.S. application Ser. No. 12/077,739 filed Mar. 20, 2008, which is a continuation-in-part of U.S. application Ser. No. 11/371,550 filed Mar. 9, 2006, which was a continuation-in-part of U.S. application Ser. No. 10/951,240 filed Sep. 27, 2004, now abandoned, which claimed priority to U.S. Provisional Application No. 60/505,794 filed Sep. 25, 2003. U.S. application Ser. No. 11/371,550 also claims the benefit of U.S. Provisional Application No. 60/660,529 filed Mar. 10, 2005. All of the above-referenced applications are incorporated herein by reference in their entireties. 
    
    
     FIELD AND BACKGROUND OF THE INVENTION 
     The Department of Justice (DOJ), the lead agency that oversees the Americans with Disabilities Act (ADA), has mandated that many municipalities and other governmental bodies comply with certain regulations regarding accessibility. One such regulation deals with accessibility on walkways in public right of ways. In brief, it requires that surfaces of those walkways enable tactile detection by visually impaired persons. 
     One of the primary ways of providing the ability to detect proximity to hazardous locations (e.g., roadways, railroad crossings, etc.) is by modifying the surface texture of the walkways. Tactilely detectable warnings are distinctive surface patterns of domes detectable by cane or underfoot, and are used to alert people with vision impairments of their approach to streets and hazardous drop-offs. The ADA Accessibility Guidelines (ADAAG) require these warnings on the surface of curb ramps, which remove a tactile cue otherwise provided by curb faces, and at other areas where pedestrian ways blend with vehicular ways. They are also required along the edges of boarding platforms in transit facilities and at the perimeter of reflecting pools. 
     Complying with the federal mandate is requiring the expenditure of much time and money by the municipalities to modify the surface textures of their sidewalks and other walkways. The need for a tactile warning device that is cost effective is essential to enable municipalities to comply with the ADA unfunded mandates. It is also needed by non-governmental entities, such as land developers, railroad companies and others who likewise need to provide tactile-detectable surfaces at curb ramps, platforms and the like. 
     Some embedded tile devices currently exist for providing tactilely detectable warning surfaces for the visually impaired in concrete walkways. Once embedded in moldable walkway materials such as concrete or asphalt, these devices form a truncated dome portion of the surface that is detectable to people on foot. 
     However, most of these devices are made out of plastic and are flimsy, being subject to ultraviolet light damage, deterioration and cracking in short periods of time. Also, inherent to the truncated dome design is the exposure of domes to severe impacts by snowplow equipment, particularly snowplow blades and end-loader buckets. Domes made of plastic tend to be sheared off, nicked or cracked when snowplows hit them. Once damaged, repair requires that entire plastic embedded tiles be removed and replaced. The fact that plastic embedded tile devices are easily damaged results in high long-term costs to maintaining truncated dome surfaces when they are employed. Yet, current manufactures of plastic embedded tile devices either do not warrant the devices or warrant them for no more than five years. Public entities cannot afford to replace truncated dome devices every five years—nor every ten to fifteen years for that matter. A more durable device is needed. 
     Information somewhat relevant to attempts to address these problems can be found in U.S. Pat. Nos. 5,775,835 to Szekely; U.S. Pat. No. 6,449,790 to Szekely; U.S. Pat. No. 6,715,956 TO Weber et al.; and, U.S. Patent Application Publication US 2004/0042850 to Provenzano, III. However, each one of these references suffers from one or more of the following disadvantages: (1) they do not enable embedment of a tile in moldable materials such as concrete or asphalt; (2) they lack means for securely interlocking a tile with the moldable material; (3) they result in build-up of moldable material around the edges of the tile when inserted, resulting in longer installation times due to the need for removal of the buildup prior to finishing; (4) the tiles do not provide means for internal air release and therefore allow trapped air pockets to obstruct the efficient movement of air and moldable material when the tile is sunk, making embedment more time-consuming and difficult, and often requiring the application of weights to prevent the tile from floating while the moldable material sets; and, (5) the tiles are not made of materials that stand up to the cracking and sheering effects of snowplows or other heavy equipment, thus resulting in high maintenance costs over time. 
     For the foregoing reasons there is a need for an embedment tile device that is designed to be both easily installable to minimize installation time and cost, and durable to minimize long-term maintenance costs and to reliably provide tactilely detectable surfaces. 
     The embedment tiles of the present invention are well-anchored and durable. Nonetheless, embedment plates in accordance with the present invention, as well as all other known embedment plates, are subject to damage from snow plows, construction equipment, and corrosive materials. Further, some existing tactile surfaces fail to comply with appropriate governmental standards because, for example, they do not have raised and truncated cones on their surface. 
     Removing non-compliant or damaged embedment tiles and installing new embedment tiles requires breaking concrete or asphalt in the area around and under the damaged embedment plate, cleaning and preparing the area for new concrete or asphalt, placing concrete or asphalt, and embedding a new tile. Such a process in time-consuming, relatively expensive, and subject to shoddy construction practices that could result in delamination of the new concrete or asphalt from existing materials. Replacement tiles have been installed over the top of damaged tiles, but matching size and contour, as well as drilling holes for fasteners, is difficult and time-consuming. Thus, it would be desirable to have simple and efficient apparatus and methods for repairing damaged embedment tiles. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided an embedment tile having a replaceable top plate, such that an upper plate that is non-compliant, damaged, or requires replacement for any other reason can be easily removed, replaced, and secured with fasteners to a lower plate of the embedment tile. The lower plate and the upper plate can both have raised conical domes of similar size, spacing, and shape such that they nest and resist damage better than a single plate surface of an embedment tile. 
     The two plates can be joined together by nuts and bolts, and in particular can be joined with nuts secured to the lower plate and bolts that extend through holes in the upper plate and are threaded into the nuts. 
     The double plated embedment tile can be preassembled at a factory and initially installed in the same way a single plate embedment tile is installed, as described herein. When the upper plate requires replacement, the bolts are removed, the upper plate is removed, the new upper plate is set and nested (if a matching tactile surface is provided) on top of the lower plate, and the bolts (or new bolts) are threaded into nuts on the lower plate. Other types of anchoring systems can also be used to secure the upper plate. 
     Alternatively, the double plated embedment tile can be initially installed with only the lower plate so that the upper plate is added after the lower plate portion is embedded in moldable material. Such an installment method reduces the overall weight of the embedment tile for ease of installation. 
     Further, with the upper plate removed, the embedment tile lower plate can include air vents to allow air to escape from under the embedment tile during installation. Air vents are particularly useful in the conical domes of the lower plate because they allow air pockets under the domes to escape and moldable material to fill the undersides of the domes to reinforce the domes from snow plow damage, for example. 
     The present invention is also directed to an embedment tile and method that satisfy this need for a device that is designed to be both easily installable to minimize installation time and cost, and durable to minimize long-term maintenance costs and to reliably provide tactilely detectable warning surfaces. Cross beams with hollow chambers are provided on the underside of the embedment tile of the present invention to enable movement of air and moldable material into the interior of the cross beams during installation thus enabling air release as well as movement of moldable material internal to the tile&#39;s cross beams. In this way, the formation of air pockets under the tile member that might otherwise resist embedment of the tile, and prevent the material from flowing smoothly to fill the spaces between the cross beams and under the lower surface of the tile more completely, is minimized. Once set, the moldable material internal to the cross beams serves to further secure the tile in place in the walkway. 
     One version of the embedment tile for embedment in a moldable material such as concrete or asphalt, comprises a tile member substantially planar in form, having an upper surface and a lower surface and two or more sides defining side edges, the upper surface having a plurality of projections extending upward there from in a tactilely detectable pattern; and, two or more cross beams projecting downward a distance from the lower surface of the tile member, each cross beam comprising a hollow chamber and a sidewall, the sidewall having two sides defining side edges and two ends defining a length of the cross beam there between, each sidewall being shaped so as to define the hollow chamber interior to and running the length of each cross beam and so as to define an opening at each end, the hollow chamber of each cross beam being in communication with an exterior via the opening at each end so as to allow air and moldable material located under the tile member to move into the hollow chambers of the cross beams during embedment of the tile in the moldable material, whereby an embedment tile is provided with cross beams having hollow chambers that allow for air release and movement of moldable material internal to the cross beams of the tile during embedment so as to ease and speed installation and to secure embedment of the tile into the moldable material. 
     In another version, air release means are provided for enhancing communication between the hollow chamber of one or more of the cross beams and the exterior so as to further enable air and moldable material to move into the hollow chamber from the exterior via said air release means during installation of the tile. The air release means may consist of one or more apertures located in the sidewall of the one or more cross beams. Alternatively, the air release means may consist of a gap formed where one side edge of the sidewall of each of said one or more cross beams approaches but does not attach to the lower surface of the tile member, the space between said side edge and the lower surface of the tile member defining the gap, the opposing edge of the sidewall connecting the cross beam to the lower surface of the tile member. 
     the sidewall of one or more of the cross beams is connected to the lower surface of the tile member by one of its two side edges, the other side edge approaching but not attaching to the lower surface of the tile member, instead defining a gap between it and the lower surface through which air and moldable material may move into the hollow chamber of the cross beam, thus further promoting movement of air and moldable material into the interior hollow chamber of the cross beams. 
     In another version, the sidewall further consists of one or more apertures and the hollow chamber of each cross beam is further in communication with the exterior via the one or more apertures. 
     In another version the projections on the upper surface of the tile member consist of a surface rising from a perimeter to a central top portion, the surface having a plurality of reinforcement ridges thereon, each reinforcement ridge extending from the perimeter toward the central top portion of the projection and functioning to reinforce the projection against damage from objects such as snow plows impacting its surface. 
     In yet another version, the embedment tile further consists of support members. Support members are attached to the lower surface of the tile member and project downward a distance there from, the distance defining a depth of the support member, the depth of the support member being greater than that of the two or more cross beams and comprising a sidewall having two opposing ends which define a length there between, the sidewall being shaped so as to define a hollow channel extending the length and an opening at each end, the chamber being in communication with the exterior at each end via the openings, whereby the moldable material is displaced around and into the openings of the support members as the embedment tile is lowered into the material. The support members may also function to support the tile member during installation. 
     In another embodiment of the present invention, the embedment tile is essentially the same as described above except for the cross beam construction. The cross beam in an alternate embodiment defines a substantially closed chamber with openings into the chamber through which a moldable material flows or is pushed. The ends of this cross beam are open and the ends of the side walls of the cross beam are tapered from top to bottom to define edges that can more easily penetrate fresh concrete. Preferably, the edges are curved to permit easier installation of the embedment tile. This arrangement also defines an opening in the lower side of a cross beam end that permits moldable material to more easily flow into the chamber, as opposed to a beam that is closed at the bottom and only open at its end. 
     In still another embedment tile in accordance with the present invention, the cross beam can be any of the cross beams disclosed herein, except that adjacent to one or more cross beams is a reinforcing member secured directly or indirectly to the bottom of the embedment plate. The reinforcing member preferably is a channel shape that opens in a downward direction. 
     Also preferably, the channel member is formed integrally with the adjacent cross beam to simplify construction because forming two members simultaneously is less expensive and more rigid, and attachment to the underside of the embedment plate is simplified. The reinforcing member provides additional rigidity to the embedment tile during and after installation. 
     In another embodiment of an embedment tile in accordance with the present invention, there is a transverse beam attached to the underside of the plate which extends at a substantially right angle to the cross beam. The transverse beam provides still more rigidity to the embedment tile. The transverse beam is preferably channel-shaped in cross section and open downward for ease of embedment into fresh concrete. 
     Also preferably, the transverse beam is positioned at the end of a cross beam and adjacent to an edge of the embedment plate. The transverse beam can be welded or otherwise attached to the underside of the embedment plate, and can be a separate member from the cross beam or connected to the cross beam for ease of attachment to the underside of the plate. 
     In other versions, the upper surface of the tile member may be skid-resistant, all or a portion of the embedment tile may be manufactured out of stainless steel, and/or its projections may consist of a surface of truncated domes distributed in a warning pattern compliant with the Americans with Disabilities Act Accessibility Guidelines. 
     In other versions, methods for making a tactilely detectable surface using the embedment tile as described above are disclosed. 
     Several objects and advantages of the present invention are: 
     providing an embedment tile with cross beams on its lower surface designed with hollow chambers, openings therein to enable air trapped under the tile during embedment to move into the hollow chambers the openings and further air release means, thus affecting internal air release and minimizing air pocket obstructions to the smooth movement of moldable material into and around the cross beams and toward the lower surface and sides during embedment of the tile; 
     means for providing tactilely detectable warning surfaces (or other surface patterns such as way-finder, decorative and the like) that are both efficiently installed and durable to enable entities to comply with ADA Accessibility Guidelines, or other requirements, rapidly and cost-effectively; 
     means for providing tactilely detectable surfaces in moldable materials such as concrete and asphalt efficiently and reliably so as to save installation time and labor costs; 
     means for providing tactilely detectable surfaces in moldable materials such as concrete and asphalt durably so as to minimize the need for replacement and thereby, the long-term costs of maintenance, by providing embedment tiles that last at least as long as the surrounding materials; 
     means for providing embedment tiles that are reusable in order to conserve materials and to minimize replacement costs; and, 
     means for providing embedment tiles with improved recyclability so as to maximally conserve environmental resources. 
     The reader is advised that this summary is not meant to be exhaustive. Further features, aspects, and advantages of the present invention will become better understood with reference to the following description, accompanying drawings and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention, reference may be made to the accompanying drawings, in which: 
         FIG. 1   a , shows a top perspective view of a version of the embedment tile  100  of the present invention; 
         FIG. 1   b , shows a bottom perspective view of the version of the embedment tile  100  depicted in  FIG. 1   a;    
         FIG. 2   a , shows a top view detail of the tile member  200  depicted in the embedment tile of  FIG. 1   a;    
         FIG. 2   b , shows the cross section indicated in  FIG. 2   a  (i.e. B-B), detailing a projection  210  and an optional edge flange  220  of the tile member  200 ; 
         FIG. 2   c , shows a side view (both sides being alike) of the tile member  200  depicted in  FIG. 2   a;    
         FIG. 2   d , shows an end view (both ends being alike) of the tile member  200  depicted in  FIG. 2   a;    
         FIG. 3   a , shows a top view of a tile member  200  similar to that of  FIG. 2   a , but showing a version of a projection  210  having reinforcement ridges  216  thereon in the upper left corner; 
         FIG. 3   b , shows a detailed top view of the ridged projection of  FIG. 3   a;    
         FIG. 3   c , shows a cross sectional view of two projections  210  denoted in  FIG. 3   a  as cross-section C-C, on the left a projection with reinforcement ridges  216  and on the right a projection without reinforcement ridges; 
         FIGS. 4   a  to  4   d , show top views of tile members  200  varying in number of sides from 2-sided to 3- and 4-sided, respectively, with  FIG. 4   d  showing a top perspective view of one version of an embedment tile  100 , having a 3-sided tile member  200 . 
         FIG. 5 , shows a bottom view of the embedment tile depicted in  FIGS. 1   a  and  1   b , showing cross beams  300  and support members  400 ; 
         FIGS. 6   a - 6   f , depict how air  910  and moldable material  900  exterior to a cross beam  300  move into the hollow chamber  340  of the cross beam when the tile is lowered during installation, arrows indicating direction of flow of the air  910  (white arrows) and of the moldable material (curved black arrows) as they are displaced by the cross beam  300  [ FIGS. 6   a - 6   c  showing movement through apertures  330   a , and  FIGS. 6   d - 6   f  showing movement through a gap  330   b];    
         FIGS. 7   a , shows a bottom perspective view of one version of the embedment tile  100  of the present invention having cross beams  300  extending downward from each side edge of the tile member  200 ; 
         FIG. 7   b , shows an end-view of the embedment tile of  FIG. 7   a , detailing certain of the structures, including air release means that include both gaps  330   b  and apertures  330   a  in the cross beams  300  (similar in cross section to the cross beam depicted at  FIG. 12   b ); 
         FIG. 8 , shows a version of a cross beam  300  (similar in cross section to that depicted at  FIG. 12   c ) having apertures  330   a  distributed along its length and noting the hollow channel  340  interior to the cross beam and in communication with an exterior via the two end openings  320  and the apertures  330   a;    
         FIG. 9 , shows side views of a cross beam  300  showing various possible versions of aperture  330   a  shape and distribution; 
         FIGS. 10   a  to  10   c , show side view details of versions of cross beams  300  present in the embedment tile of  FIGS. 1   b  and  5 , which vary in length and in number of apertures  330   a;    
         FIG. 11   a , shows a bottom perspective view of a version of the embedment tile  100  of the present invention showing cross beams  300  extending down from each edge of the tile member  200  (similar in cross section to that depicted in  FIG. 12   a ) and a central cross beam  300  (similar in cross section to that depicted in  FIG. 12   c ); 
         FIG. 11   b , shows the bottom perspective view of  FIG. 11   a  cut in cross section as indicated; 
         FIG. 11   c , shows an end view of the embedment tile of  FIG. 11   a , showing details of the edge cross beams  300 ; 
         FIG. 12   a - 12   f , show cross sectional views of several versions of the cross beams  300  of the present invention,  FIGS. 12   a  and  12   b  of the type in which a gap  330   b  is formed when one side edge of the cross beam approaches but does not meet the lower surface of the tile member  200 ; 
         FIGS. 12   c - 12   f  show versions of cross beams  300  that attach at both side edges, or portions of the sidewalls proximate thereto; 
         FIG. 13 , shows cross-sectional views of versions of the cross beams  300  which vary in shape of the side wall  310 ; 
         FIG. 14   a , shows a side view of the embedment tile depicted in  FIGS. 1   a  and  1   b;    
         FIG. 14   b , shows the detail “A” of  FIG. 14   a , enlarged to show apertures and the location of a cross beam perpendicularly to another aligned to allow optional insertion of reinforcement bars there through; 
         FIG. 14   c , shows an end view of the embedment tile depicted in  FIGS. 1   a  and  1   b;    
         FIG. 15 , shows a side view and several cross sectional views of versions of the support member  400 ; 
         FIG. 16  is a partial perspective view of the underside of an alternate view of an embedment tile having cross beams with rounded ends and a lower beam end opening in accordance with the present invention; 
         FIG. 17  is an isolated perspective view of the cross beam of  FIG. 16 ; 
         FIG. 18  is a perspective view of the underside of an alternate view of an embedment tile having cross beams with rounded ends, a lower beam opening, and adjacent reinforcing channels in accordance with the present invention; 
         FIG. 19  is an isolated perspective view of the cross beam and reinforcing channel of  FIG. 18 ; 
         FIG. 20  is a partial perspective view of a cross-section of the cross beam of  FIG. 18 ; 
         FIG. 21  is a perspective view of the underside of another alternate embodiment of an embedment tile having transverse reinforcing channels in accordance with the present invention; 
         FIG. 22  is a partial perspective view of the underside of the embedment tile of  FIG. 21 ; 
         FIG. 23  is a side view of an upper plate and a lower plate in accordance with the present invention; 
         FIG. 24  is a perspective side view of the underside of a double plated embedment tile in accordance with the present invention, with the lower plate moved away from the upper plate; 
         FIG. 25  is an exploded and perspective view of the top of an embedment tile in accordance with the present invention; 
         FIG. 26  is a top view of the embedment tile replaceable top plate in accordance with the present invention; 
         FIG. 27  is an exploded and perspective view of a bottom of the embedment tile of  FIG. 25  in accordance with the present invention; 
         FIG. 28  is a perspective view of a portion of a top plate and a portion of a bottom plate for an embedment tile in accordance with the present invention; 
         FIG. 29  is a side view of top plate fasteners and anchors for use in the embedment plate of the present invention; and 
         FIG. 30  is a top view of a plurality of wedge-shaped embedment tiles in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now specifically to the figures, in which identical or similar parts are designated by the same reference numerals throughout, a detailed description of the present invention is given. It should be understood that the following detailed description relates to the best presently known embodiment(s) of the invention. However, the present invention can assume numerous other embodiments, as will become apparent to those skilled in the art, without departing from the appended claims. For example, though the present embedment tile is described relative to embedment in moldable materials such as concrete or asphalt, it may also be embedded in other types of materials. Also, though the tactilely detectable surface of the embedment tile is described as producing a warning pattern compliant with ADA Accessibility Guidelines, any pattern may be produced, including way-finder patterns, purely decorative patterns, emblematic patterns or patterns of other sorts. 
     It should also be understood that, while the methods disclosed herein may be described and shown with reference to particular steps performed in a particular order, these steps may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the present invention. Accordingly, unless specifically indicated herein, the order and grouping of the steps is not a limitation of the present invention. 
     Detailed Description—Embedment Tile 
     Referring to  FIGS. 1   a  and  1   b , one version of the embedment tile device of the present invention is depicted. This version of the embedment tile device  100  is designed for embedment in walkways made of moldable materials  900  such as concrete or asphalt (see  FIGS. 6   a - 6   f  for depictions of embedment of tiles into materials  900 ), in order to bring them into compliance with the Americans with Disabilities Act Accessibility Guidelines (ADAAG) by producing tactilely detectable warning surfaces. Though the accompanying drawings and following description relate to use of the embedment tile  100  for creating tactilely detectible warning surfaces, the reader is reminded that the tiles  100  may be used to produce other surface patterns in a variety of places other than walkways specifically, and in a variety of moldable materials  900  other than concrete and asphalt. 
     The embedment tile  100  comprises a tile member  200  and two or more cross beams  300 . It may also comprise air release means  300  ( a  or  b ) and optionally also two or more support members  400 . 
     The tile member  200  is substantially planar in form, having an upper surface (shown in  FIGS. 1   a ,  2   a , and  3   a ) and a lower surface (shown in  FIGS. 1   b ,  5 ,  7   a , and  11   a ) and two or more sides defining side edges. As depicted in most of the figures, the tile member  200  has 4 side edges. However, the same design can be constructed to meet the needs of a user for different shapes, including, for example, skewed curb ramp approaches, blended sidewalk approaches, sides of curb ramp approaches and the like where the number of side edges may vary (see  FIGS. 4   a - 4   c  for examples of 2-, 3-, and 4-sided versions, respectively, with detail of one type of triangular tile member shown at  FIG. 4   d ). Tile members  200  may further be cut for customized fitting to certain areas. 
     The tile member  200 ′s upper surface comprises many projections  210  extending upward from the surface (see  FIGS. 1   a ,  2   a , and  3   a ). Each projection  210  generally consists of a surface rising from a perimeter  212  to a central top portion  214  ( FIG. 2   b ). As shown in the figures, the projections  210  are shaped like truncated domes where the projection&#39;s surface rises from a circular perimeter  212  to a flattened central top portion  214  (i.e., forming the truncated dome). Also as depicted, these projections  210  are distributed in a tactilely detectable warning pattern, i.e., the domes  210  are distributed in a matrix of rows and columns in conformance with the ADAAG. As the ADA guidelines evolve over time or as users require conformance with other guidelines, the projections  210  may be altered in form, size, distribution pattern and spacing to meet those new requirements. For example, users may require the projections  210  to form a way-finder pattern, decorative design or some other pattern. 
     The projections  210  may further comprise several reinforcement ridges  216  (see  FIG. 3   a - 3   c ). Reinforced ridges  216  function to strengthen projections  210  so that they are better able to endure impacts from other objects, to better protect the tile&#39;s surface coatings from wear, and to enhance the slip-resistance of the domes  210  themselves. 
       FIG. 3   c  shows one truncated dome  210  with ridges  216  (on left) and one dome  210  without ridges  216  (on right) to illustrate the difference. In  FIG. 3   b , a top view is given to show that, in this particular version,  8  reinforcement ridges  216  are distributed evenly along the sides of the dome  210 , extending from the perimeter  212  of each dome toward the center top portion  214 , in this case extending slightly above the edge of the truncated top surface of the dome  210 . In this way, an object impacting the dome  210  from any side, such as the blade of a snow plow when directed over a tile  100 , would first hit one or more of the reinforcement ridges  216  on several of the domes  210 . The ridge(s)  216  which would in turn lesson and/or divert impact of the object up and over the tops of the domes  210 , thereby protect the domes. Likewise, the surface coating of the domes, including coatings on the top surface of the domes, would also be protected. In this way the reinforcement ridges  216  function to protect not only the underlying domes themselves but also the coatings on the surfaces of the domes. This results in higher durability of both the domes and the coatings, reducing the frequency with which either needs to be replaced. 
     The number, distribution pattern and sizing of the ridges  216  may vary according to the particular application and the particular type and sizing of upwardly extending projections  210  (e.g., according to whether the projections  210  are formed as truncated domes, diamonds or otherwise). The sizes depicted in  FIGS. 3   a - 3   c  (inches [cm]), are given by way of example only. 
     The reinforcement ridges  216  may be formed by various methods. In versions of embedment tiles  100  made from sheets of stainless steel or other metals, the domes  210  complete with reinforcement ridges  216  may be formed using a press. Other alternatives to forming the upwardly extending projections complete with ridges  216  may be employed, including forming them by molding or otherwise depending on the materials used (e.g., plastics, etc.). 
     Referring to  FIGS. 2   a  to  2   d , detailed views of the version of the tile member  200  depicted in  FIG. 1   a  are provided. A top view is provided in  FIG. 2   a , side view in  FIG. 2   c  and an end view in  FIG. 2   d .  FIG. 2   b  shows a cross-sectional view through one of the truncated dome projections  210  and one edge of the tile member  200  (defined as section B-B in  FIG. 2   a ). 
     Note that in  FIGS. 2   b  to  2   d , a vertical flange  220  is shown extending vertically downward from each edge of the tile member  200 . Vertical flanges  220  are optional. When present, however, the vertical flanges  220  may function to further stabilize the tile member  200  and enable the easy connection of additional embedment tiles  100  as may be necessary to extend or expand surface projection areas by bolting them together at the flanges  220  (note that bolt holes  222  are shown in the vertical flanges  220  as depicted in  FIGS. 1   a - 1   b ,  2   c - 2   d ). Alternatively, in versions with cross beams  300  located at the edges of a tile member  200 , bolt holes  222  may be located in the sidewalls  310  of the cross beams (see, e.g.,  FIG. 7   b ). 
     As mentioned above, the size of the tile member  200  as well as its shape and number of sides may vary depending on a user&#39;s needs (see shape variations in  FIGS. 4   a - 4   d ). By way of example, in one version as depicted in  FIGS. 1   a ,  1   b , and  2   a - 2   d , the tile member is about 24.0 inches (61 cm) wide by 48.0 inches (122 cm) long. Many other shapes and sizes are possible, including 2 foot square versions (24.0×24.0 inches; 61×61 cm) and the like. 
     The upper surface of the tile member  200  may further be conditioned or surfaced so as to provide skid-resistance. For example, if the tile member  200  is made of a metal material, such as stainless steel, the upper surface might be etched or otherwise surfaced to provide skid-resistance. In addition or alternatively, the upper surface may be coated with a material to improve or provide its skid-resistant quality. Color for improved visual contrast of the embedment tile  100  may further be provided by treatment of the embedment tile  100 &#39;s material itself, and/or by coating it with a colorant. A variety of techniques may be used to impart the embedment tile  100  with long-lasting color contrasting and skid resistance. 
     The embedment tile  100  further comprises two or more cross beams  300  that are attached to and project downward a distance from the lower surface of the tile member  200 , the distance defining a depth  360  of the cross beams  300  (see  FIGS. 1   b  and  5 , in which five cross beams  300  are shown; see  FIG. 8  for example of an individual cross beam noting depth dimension  360 ; see below for discussion of other versions of cross beams  300 ). 
     Each cross beam  300  generally consists of a hollow chamber  340  and a sidewall  310 . The sidewall  310  has two sides defining side edges and two ends defining a length of the cross beam there between. The sidewall  310  is shaped (via bending, molding or the like) so as to define the 3-dimensional shape of the cross beam  300 , to define and to enclose, or substantially enclose, a hollow chamber  340  interior to and running the length of each cross beam  300 , and to define an opening  320  at each end. The hollow chamber  340  of each cross beam is in communication with the exterior via the openings  240  at each end so as to allow air  910  and moldable material  900  located under the tile member  200  to move into the hollow chambers  340  of the two or more cross beams via the openings  320  during embedment of the tile in the moldable material  900 . 
     In this way, the hollow chambers  340  of the cross beams  300  allow for air release and movement of moldable material  900  internal to the cross beams (i.e., into their interior hollow channels) during embedment. All of the air  910  trapped under the tile  100  as it is lowered into the moldable material  900 , need not move out to the edges of the tile member  200 . Instead, most may move into the hollow chambers  340  of the cross beams  300 . This greatly improves ease and speed of installation because it prevents formation of air pockets that would otherwise be trapped under the tile member  200  and prevent smooth movement of material  900  up between the cross beams  300 . Because some of the moldable material  900  also may move into the hollow chambers  340  of the cross beams  300 , embedment of the tile into the moldable material  900  is further secured once it sets. 
     The tile  100  may further consist of air release means  330  ( a  or  b ) for enhancing communication between the hollow chamber  340  of one or more of the cross beams  300  and the exterior so as to further enable air  910  and moldable material  900  to move into the hollow chamber from the exterior via the air release means  330   a,b  during installation of the tile (see  FIGS. 6   a - f ). Inclusion of air release means  330   a,b  may particularly improve installation when the length of the cross beams  300  approaches that of the tile member  200  (versus shorter lengths where the openings  320  alone provide sufficient air release). 
     The air release means may comprise one or more apertures  330   a  located in the sidewall  310  of one or more of the cross beams  300  (see  FIGS. 6   a - c , also, most of the figures in which cross beams are depicted). Alternatively, the air release means may comprise a gap  330   b  formed where one side edge of the sidewall  310  of each of the one or more cross beams  300  approaches but does not attach to the lower surface of the tile member, the space between the side edge and the lower surface of the tile member  200  defining the gap  330   b  (see  FIGS. 6   d - f ; see also  FIG. 7   b ,  12   a - b ). In this case, the opposing edge of the sidewall  310  connects the cross beam  300  to the lower surface of the tile member  200 . 
     Provision of air release means in the form of apertures  330   a  in the sidewalls  310  and/or gaps  330   b  between side edges of the sidewalls  310  and the lower surface of the tile member  200 , promotes greater air release during installation further promoting ease and rapidity of the installation process [see  FIGS. 6   a - 6   d  for illustrations of the internal air release process in cross sectional view of a cross-beam having apertures  330   a  ( FIGS. 6   a - 6   c ) and having a gap  330   b  ( FIGS. 6   d - f ) and below for further discussion of these features]. 
     Without the hollow chamber  340  in communication with the exterior (via the openings and/or air release means  300   a  and/or  300   b ), pockets of trapped air  910  would form under the tile as it is lowered during installation and the air pockets would exert a force upward against the lower surface of the tile member  200 , thus resisting insertion of the tile into the material  900 . This situation often requires the use of weights during installation in order to keep the tile  100  in place at the desired grade. Free from the resistance of air pockets, the embedment tile  100  of the present invention meets with little resistance and eases into the moldable material  900  flawlessly and rapidly for efficient installation. Air pockets  910  also prevent even flow of moldable material  900  to fill the areas between the cross beams  300  and up against the lower surface of the tile member  200 . Thus, enabling release of air pockets  910  into the interior hollow chambers  340  of the cross beams  300  of the present invention, further removes the air pocket obstacle to smooth flow of moldable materials  900  up to more fully fill the spaces between the cross beams  300  and under the lower surface of the tile member  200 . More complete filling of those spaces with moldable materials  900  further strengthens support for the tile member  200  once installed. 
     Gap air release means  330   b , are formed when the sidewall  310  of one or more of the cross beams  300  connects to the lower surface of the tile member  200  by one of its two side edges, the other side edge approaching but not attaching to the lower surface of the tile member  200 , thus instead defining the gap  330   b  between it and the lower surface (see  FIGS. 7   a - 7   b  for a version of the tile  100  showing cross beams  300  formed to produce gaps  330   b ). Air  910  and moldable material  900  may move into the hollow chamber  340  of the cross beam through the gap  330   b  in addition to through the openings  320 , thus improving internal air release during installation (see  FIGS. 6   d - f ). 
     Aperture air release means  330   a , like gaps  330   b , also provide channels of communication between the hollow chamber  340  of each cross beam  300  and the exterior (see  FIG. 8  and almost all other figures showing cross beams  300  for examples of apertures  330 ). Air  910  and moldable material  900  may move into the hollow chambers  340  of the cross beams  300  via the apertures  330   a  in addition to through the openings  320  and gaps  330   b  (when present) to greatly improve internal air release during installation (see  FIGS. 6   a - 6   c ). 
     Aperture air release means  330   a , though generally illustrated as circular openings, may be variously shaped (e.g., rectangular, saw-toothed, triangular, oval, square and the like) and variably distributed in the sidewalls  310  of cross beams (See  FIG. 9  for examples). The number and size of the apertures  330  may vary with the depth and length of the cross beam  300 . Several cross beams  300  of varying lengths are depicted in  FIGS. 10   a - 10   c  in side view. In these versions, as length increases, so do the number of apertures  330 , though the number and distribution of apertures  330  may vary and are not necessarily proportional to length of the cross beam  300 . 
     In versions with apertures  330   a  and/or gaps  330   b , some moldable material  900 , in addition to air  910 , also flows into the interior hollow chambers  340  of the cross beams  300 . This tends to strengthen contact between the surrounding matrix and the cross beams  300  and interlock the beams  300  with the walkway when the moldable material sets and hardens. This results in excellent securement of the tile  100 . The resultant release of air pockets  910  into the interior hollow channels  340  of the cross beams also removes their restriction to the movement of moldable material  900 , thus enhancing its flow up toward the lower surface of the tile member  200  to more completely fill the areas between the cross beams  300 . The resultant substantially complete filling of the underside of the tile member  200  with moldable material  900  further strengthens the tile  100  once installed in a walkway or the like. 
     The cross beams  300  themselves may vary in size and shape. For example, the depth  360  of the cross beam  300  may typically vary between 2.0 inches (5.1 cm) to 2.5 inches (6.3 cm). However, many other depths  360  are possible depending on the particular application. Likewise, cross beam lengths may vary. 
     The cross beams  300  may be distributed on the lower surface of the tile member  200  in various ways. As depicted in  FIG. 5 , two longer cross beams  300  (detailed in  FIG. 10   c ) are located length wise toward the outer edges of the lower surface of the tile member  200 . Two cross beams  300  of shorter length (detailed in  FIG. 10   a ) are located at opposite ends of the lower surface of the tile member  200  so as to span the distance between and to rest perpendicularly to the two longer beams  300 . A fifth cross beam  300  (detailed in  FIG. 10   b ) is located lengthwise down the middle of the lower surface of the tile member  200  in parallel to and midway between the two longer cross beams  300 , and spanning the distance between the two short cross beams  300  running perpendicular to them. Other orientations (such as diagonal) and numbers of cross beams  300  may be employed also. As shown in  FIG. 7   a , cross beams  300  are distributed only at each side edge of the tile member  200 . In  FIG. 11   a , edge cross beams  300  like in  FIG. 7   a  are present with addition of a central cross beam  300  running substantially the entire length of the middle of the tile member  200 . 
     Cross beams  300  may likewise connect to the lower surface of the tile member  200  in various ways (see  FIGS. 12   a - 12   f ).  FIGS. 12   a  and  12   b  show connection of one side edge  312  of the sidewall  310  only so as to form the gap  330   b  where the opposite side edge of the sidewall approaches the lower surface of the tile member  200 , but does not quite meet. The connection in these cases may be made by a simple bend in the tile member, with subsequent bends in the thus-defined sidewall portion  310  of the cross beams to define its 3-dimensional structure and hollow chamber  340  within.  FIGS. 12   c - 12   f  show alternative formations of the sidewall  310  so that both edges  312 , or portions of the sidewall proximate the edges, connect to the lower surface of the tile member  200  ( FIG. 8  shows perspective view of  FIG. 12   c  version). Connection in these cases may be made in a variety of ways such as by welding in the case of metal cross beams. 
     Likewise, the shaping of the sidewall  310  may vary (see  FIG. 13  for cross-sectional views depicting various shapes). The sidewalls  310  of the cross beams  300  may be shaped so that the cross beams are substantially V-shaped in cross section as in the version depicted in most of the figures. The V-shape functions well to enable the cross beams  300  to embed efficiently in wet moldable material  900  such as concrete or asphalt, acting to move the moldable material  900  into and around the cross beams  300  and to provide the interior cavity (i.e., hollow chamber  340 ) into which air  910  trapped under the tile member  200  may escape so as to enable insertion (as shown in  FIGS. 6   a - 6   f ). However, as mentioned previously, the sidewall  310  may be formed to other cross-sectional shapes as well that function likewise such as U-shaped, round, square or otherwise (see  FIG. 13 ). 
     As can be seen from the above, cross beams  300  with their hollow chambers  340 , function both to stabilize the tile member  200  and to provide good internal air release to enhance the flow of trapped air  910  and material  900  into (via the end openings  320 , and apertures  330   a  and/or gaps  330   b ) and around the cross beams  300  toward the lower surface and sides of the tile member  200  as the tile  100  is lowered into the moldable material  900 , thus easing the embedment tile  100  down into the material and thereby facilitating rapid embedment of the tile  100  (see  FIGS. 6   a - 6   f ). In versions of the tile member  200  where the projections  210  on the upper surface are accompanied by matching indentations on the lower surface below (as illustrated in  FIGS. 1   b ,  2   b ,  6   a - 6   f ), the cross beams  300  also function to move the material  900  into the indentations, minimizing voids therein and thereby further fortifying the projections  210  above against cracking and breaking from heavy equipment. 
     As mentioned previously, once the material  900  sets and hardens, the portions of same which flowed into the hollow chambers  340  of the cross beams  300  (via the end openings  320  and apertures  330   a  and/or gaps  330   b ) function to interlock the tile  100  with the hardened material  900 . However, to further improve interlocking, reinforced steel bars (reinforcement bars or, re-bars, L-bars, tie-bars and the like) may optionally be employed. These are sometimes desired by designers to assist with unusual applications. The re-bars may be inserted through the or into the cross beam  300  and/or support beam  400  (see below) chambers  340 / 440 , and/or the apertures  330   a . In some versions of the cross beams  300 , additional re-bar apertures  332  may be provided to enable more options for insertion of re-bars. 
     Referring to  FIGS. 14   a - c , detailed views of a version of the tile  100  of the present invention are shown [side view and enlargement of a portion thereof ( FIGS. 14   a,b ), and end view ( FIG. 14   c ]. In  FIG. 14   b , a detail of one version of cross beams  300  is shown with a re-bar aperture  332  located in one cross beam  300  so as to allow a reinforcement bar to be inserted at least partly there through and extend through an adjacent and perpendicularly oriented cross beam  300 &#39;s hollow chamber  340 . Many variations on orientation of air release apertures  330   a  and re-bar apertures  332  may be employed according to the needs of the user. 
     In some applications, tie-bars may be used to tie the tiles  100  to the surrounding concrete, particularly for tying narrow strips of concrete to the tile  100  and to keep tooled or untooled cracks (joints) from moving or offsetting. In general, tie-bars would extend through tooled in concrete joints in the sidewalk. The use of reinforced steel bars further stabilizes the embedment tile  100  and strengthens the interlocking between it and the concrete. Reinforcement bars may further aid in joining adjacent embedment tiles  100  to form larger areas of surface projections  210 . Reinforcement bars may still further function in securing the embedment tile  100  in place during installation (see Method section below). 
     The embedment tile  100  may optionally further consist of two or more support members  400  (see  FIGS. 1   b ,  5 ,  14   a ,  14   c ,  15 ) which function as support of the tile member  200  during installation. Support members  400  are attached to and project downward from the lower surface of the tile member  200  for a distance defining a depth  460  greater than the depth  360  of the two or more cross beams  300 . The support members  400  may be two-dimensional and affixed perpendicularly in orientation to the lower surface of the tile member  200 . Alternatively, the support members  400  may be three-dimensional constructs similar to the cross beams  300 , but shorter in length as depicted in the figures referenced above. 
     In their three-dimensional version, support members  400  consist of a sidewall  410  having two opposing ends which define a length there between. The sidewall  410  is shaped so as to define a hollow channel  440  extending the length and an opening  420  at each end, the channel  440  being in communication with the exterior via the openings  420 . In this way materials  900  may be displaced around and into the openings  420  as the embedment tile  100  is embedded in the concrete (similarly to how the cross beams  300  function). Thus an interlocking function is provided by the support members  400  once the moldable material  900  hardens in and around them, helping to further secure the tile  100  in the material  900  when it hardens. 
     Note that the support member sidewall  410  may assume various shapes in cross section similarly to those of the cross beams  300 . Referring to  FIG. 15 , the sidewall  410  in a substantially V-format is shown. As can be seen, it may be bent to open the chamber  440  to the exterior along its length as in the two lower cross-sectional views. These more open versions may facilitate bending in circumstances where users must fit the embedment tiles  100  in odd places and positions relative to other objects, affording the user flexibility in how they may manipulate the support members  400 . 
     As mentioned above, the support members  400  project downward from the lower surface of the tile member  200  for a depth  460  greater than the depth  360  of the two or more cross beams  300 . By so doing, the support members  400  may further function to hold the tile member  200  at the appropriate level above the sub-layer of the walkway (e.g. at the surface height of the walkway) during pouring operations thereby providing an area for the moldable material  900  to flow around and underneath (see descriptions in method section of this alternative method of installation). This enables a user to install the tile  100  quickly into material  900  such as fresh concrete and to work from the surface of the tile member  200  to finish around the embedment tile  100  as necessary. Concrete finishing operations can continue without delay when using the embedment tile  100  with support members  400  attached. 
       FIG. 16  depicts an embedment tile  402  with a tile member  200 , flanges  220 , and at least one cross beam  300 . The cross beams  300  have side walls  310 , openings in the ends  320 , and apertures  330  to define a substantially enclosed chamber  340 . These parts are substantially the same as those described above, except that the ends  320  of the sidewalls  310  are not entirely perpendicular to the tile member  200 . 
     Instead, the ends  320  of the cross beam  300  side walls  310  define downwardly facing edges  350  that are preferably tapered, and more preferably rounded down and inward to the bottom of the v-shape defined by the side walls  310  so that the end of the cross beam includes a lower open portion  313  through which moldable material can more easily enter the chamber  340 . The illustrated taper is an arcuate portion  312  at the lower ends of the side walls  310 . The arcuate portion  312  extends down and inward relative to the tile member  200 . The edges  350  make it easier to embed the tile  200  into moldable material  900  such as concrete or asphalt by creating a slicing action that helps displace moldable material  900  while the tile  200  is being installed. Other shapes of edges  350  can be used, such as a straight taper, a stepped taper, and the like. The lower open portion  313  could even be at the bottom of a cross beam  300  without any end taper to provide a cross beam  300  in accordance with the present invention that is easier to install than a beam  300  with no lower open portion near the end. These lower openings permit moldable material to move into the chamber  340  more easily than an end that has no lower opening. 
     Holes  332  are smaller than openings  330  because the holes  332  are intended to have reinforcing steel bars extending through them for installations requiring such additional anchoring (in bridge decks or poured in place applications, for example) of the embedment tiles and/or reinforcement of the moldable material. 
     Holes  334  are defined by the tile member flanges  220  and can be used to match up and joined with an adjacent embedment tile with bolts or other connectors when it is desired to connect tile members  200  together before installation. 
       FIGS. 18 ,  19 , and  20  illustrate yet another embodiment of an embedment tile  404  in accordance with the present invention. This embodiment includes a tile member  200  with flanges  220 . In this embodiment, there are reinforcing members  370  in the form of channels. The reinforcing members  370  are preferred in some applications to make the tile member  200  more rigid during installation, and after installation if there happen to be any air gaps beneath the tile member  200 . Although depicted as a channel, the reinforcing member  370  could be other shapes as well. 
     The reinforcing member  370  can be a separate element, but preferably, the reinforcing member  370  is formed integrally with the cross beam  300  for added strength and easier manufacturing. The cross beam  300  and reinforcing member  370  are also preferably made of rolled stainless steel, but other materials could be used. It is also possible to form the cross beam  300  and reinforcing member  370  separately, and connecting them with a weld, for example, before attachment to the underside of the tile member  200 . 
     The reinforcing member  370  is preferably connected directly to the underside of the tile member  200  to provide optimum rigidity. This connection can be by welding, rivets, bolts, screws or any other type of connection. 
     In this embodiment, the cross beam  300  openings  330  are triangular in shape with their points directed downwardly. Such shapes may be desirable from a manufacturing standpoint, but any shape of opening  330  could be used. Preferably, when triangular shaped openings are used, they are oriented with their points directed upwardly (or opposite that shown in  FIGS. 18 ,  21 , and  22 ). Having the widest portion of the triangular opening in the lower portion of the cross beam  300  enables moldable material to flow into the chamber  340  more easily. This also reduces installation time. 
     As best seen in  FIGS. 19 and 20 , the cross section of the cross beam  300  is slightly different from the triangular shape described in earlier embodiments. In this embodiment, the cross beam  300  and reinforcing member  370  are formed integrally which results in the side walls  310  of the cross beam  300  including a portion  375  that is rolled to a more vertical shape. This shape can provide additional rigidity, especially when combined with the reinforcing members  370 , as illustrated. Other shapes of cross beams  300  can be used in the present invention, as well. 
       FIGS. 20 and 21  illustrate a variation in the embedment tile  406  of the present invention. To provide additional rigidity, a transverse reinforcing member  380  is added adjacent to the edge of the tile member  200  even when a flange  220  is present. The transverse reinforcing member  380  is illustrated in the form of a channel for efficient penetration into the moldable material  900 , but other shapes and sizes can be used in this embodiment of the present invention. 
     The transverse reinforcing members  380  preferably extend substantially the entire width of the tile member  200 , but other lengths could be used as well. When the transverse reinforcing member  380  is used adjacent to a flange  220 , the cross beam  300  is preferably cut short to provide space. This minor change in length of the cross beam does not significantly affect the embedment strength or rigidity of the cross beam  300 . 
     Transverse reinforcing members  380  can be used at one edge of the tile member  200  only, or two can be used at opposite edges or any number can be used between the plate edges. When transverse reinforcing members  380  are used away from the edges of the tile member  200  they are preferably sized to fit between the cross beams  300 . 
     When transverse reinforcing members  380  are used, they are preferably of a similar depth as the tile member flanges  220 . To accommodate bolts through the bolt holes  334  for connecting adjacent embedment tiles, the transverse reinforcing members  380  include notches  338  that are aligned with the bolt holes  334  and are preferably oversized to accommodate nuts and washers. ( FIG. 22 ). 
     Suitable materials for embedment tiles in accordance with the present invention include: plastic, composite materials, metal, coated metal, anodized or galvanized metal, cast iron, stainless steel (particularly grades  304  and  439  in a 16 gauge thickness) or any other suitable material. 
     The embedment tile  100  may be made in whole or in part, out of a variety of materials. Stainless steel has advantages of strength, durability and recyclability. However, the embedment tile  100  may be made out of other hard, durable materials such as galvanized steel, other metals, hard plastics, fiber reinforced plastics, resins and the like. As technology evolves, other types of metals, plastics, resins and the like may be developed that may be used to provide the durability needed in the tile member  200  and its projections  210 , among other parts of the embedment tile  100 . 
     One advantage of using stainless steel is that it is recyclable, thus conserving resources, and highly durable. Stainless steel will not be damaged by ultraviolet light, will not crack and will withstand heavy vehicle loading, e.g., snowplow equipment (including snow plows, end loaders, skid loaders) and heavy truck traffic across the domed area of the walkway. Unlike plastic dome projections  210  which experience all of the preceding types of damage, steel dome projections  210  will not sheer off when hit by snowplows and the like and will last as long as the concrete around them does. Maintenance of stainless steel embedment tiles  100  is, therefore, largely limited to periodically resurfacing an optional topcoat as necessary to maintain color contrast and skid resistance. The frequency and cost of maintenance over the long-term is thus minimized. The high durability of steel embedment tiles  100  ensures that the tactile-detectible surface is compliant with ADA requirements and that the surface is therefore, in condition to safely warn the blind and other users. 
     In those cases where ramped walkways, including the tactilely-detectable surface areas are removed from time to time for utility repairs or other necessary work, the embedment tile  100  can be removed for re-use again at the same site or other locations. This further reduces the costs of using the stainless steel version of the embedment tiles  100 . 
     Detailed Description—Method 
     The various versions of the embedment tile  100  of the present invention may be embedded in fresh moldable material  900  in various ways. Following are descriptions of two basic methods, though others may be employed. The descriptions specify how to embed the tile  100  in fresh concrete. However, the basic methodology may be applied to other moldable materials  900  such as fresh asphalt. 
     The design of the embedment tile  100  enables installation to proceed easily and rapidly. For example, certain versions of the embedment tile  100  require only about 1 minute or less to install in concrete. 
     In general, the embedment tile  100  is either (a) embedded into already poured wet concrete (or other moldable material  900 ) or (b) is secured in place before the concrete is poured to fill in the walkway or other surface areas around and underneath the embedment tile  100 . Once installed, the embedment tile  100  provides a pattern of projections  210  on its upper surface that remains exposed to pedestrian traffic once the concrete sets and hardens to provide a surface that is tactilely-detectable to pedestrians. 
     One version of the method for producing a tactilely detectable surface in concrete comprises providing a version of the embedment tile  100  described above for embedment in wet concrete. A user installs the embedment tile  100  by (a) lowering the embedment tile  100  into the concrete; and, (b) positioning the upper surface of the tile member  200  relative to a surface of the surrounding concrete as desired and so that the upper surface&#39;s tactilely-detectable pattern of projections  210  is exposed. A user may optionally work from the surface of embedment tile  100 , finishing (and optionally also edging) around the two or more edges of the embedment tile  100 . The concrete is then allowed to set and interlocking to occur between the embedment tile  100  and the hardened concrete. 
     Another version of the method for producing a tactilely detectable surface in concrete also comprises providing a version of the embedment tile  100  described above prior to pouring wet concrete. In this version however, a user installs the embedment tile  100  by (a) securing the embedment tile in place relative to an existing sub-base or newly prepared sub-base; (b) adjusting the embedment tile  100  to meet slope or grade requirements (e.g., those set by the ADA Accessibility Guidelines or other requirements of the user); and, (c) pouring the concrete onto the sub-base in a formed area and under and around the embedment tile  100 . A user may work from the surface of embedment tile  100 , working the concrete under and around the embedment tile  100  and finishing (and optionally also edging) around the two or more edges of the embedment tile  100 . The concrete is then allowed to set and interlocking to occur between the embedment tile  100  and the hardened concrete. This version may further comprise using a concrete vibrator to consolidate the concrete. 
     Securing the embedment tile  100  in place may comprise (a) anchoring the embedment tile  100  to the sub-base, or (b) suspending the tile above the sub-base. 
     Anchoring the embedment tile  100  will generally involve resting the embedment tile  100  on the sub-base or a portion thereof [depending on version, it may rest on the sub-base (or shims placed on the sub-base) by its cross-beams  300  or by its support members  400 ]. Once resting in place, one or more weights (such as sand bags, cement blocks, or the like) may be placed directly on the upper surface of the embedment tile  100 . Alternatively, L-shaped reinforcement bars (or, re-bars) may be placed through or into the bottom portions of hollow channels  440  of the support members  400  (or if resting on cross-beams  300 , through the bottom portions of hollow chambers  340 ) and secured to the sub-base by pushing or tapping the reinforcement bars down into the sub-base. Likewise, other types of reinforcement bars and means for anchoring the embedment tile  100  may be employed. 
     Alternatively, securing the embedment tile  100  in place may consist of suspending the embedment tile  100  above the sub-base before the concrete is poured. In one version, the embedment tile  100  is suspended above the sub-base by placing L-shaped reinforcement bars (or, re-bars) into the hollow chambers  340  of the cross beams  300  or bar aperture&#39;s  332  of cross beams  300  and securing the other ends of the reinforcement bars into the sub-base by pushing or tapping the reinforcement bars down into the sub-base. Alternatively, suspending the embedment tile  100  may be accomplished by securing a wood board or other rigid material to the upper surface of the embedment tile  100 , then resting ends of the wood board on an existing portion of concrete surface (such as a walkway and back of curb and gutter) to hold the embedment tile  100  to grade. Other alternatives for suspending the embedment tile  100  may also be employed. 
     Advantages of the Invention 
     The previously described versions of the present invention have many advantages, including: 
     providing an embedment tile with cross beams on its lower surface designed with hollow chambers, openings therein to enable air trapped under the tile during embedment to move into the hollow chambers the openings and further air release means, thus affecting internal air release and minimizing air pocket obstructions to the smooth movement of moldable material into and around the cross beams and toward the lower surface and sides during embedment of the tile; 
     means for providing tactilely detectable warning surfaces (or other surface patterns such as way-finder, decorative and the like) that are both efficiently installed and durable to enable entities to comply with ADA Accessibility Guidelines, or other requirements, rapidly and cost-effectively; 
     means for providing tactilely detectable surfaces in moldable materials such as concrete and asphalt efficiently and reliably so as to save installation time and labor costs; 
     means for providing tactilely detectable surfaces in moldable materials such as concrete and asphalt durably so as to minimize the need for replacement and thereby, the long-term costs of maintenance, by providing embedment tiles that last at least as long as the surrounding materials; 
     means for providing embedment tiles that are reusable in order to conserve materials and to minimize replacement costs; and, 
     means for providing embedment tiles with improved recyclability so as to maximally conserve environmental resources. 
     The present invention does not require that all the advantageous features and all the advantages need to be incorporated into every embodiment thereof. 
     Depicted in  FIGS. 23 to 27  is an embedment tile  480  with a replaceable top plate of the present invention, having a double plated surface, such that an upper plate  482  that is non-compliant, damaged, or requires replacement for any other reason can be easily removed, replaced, and secured with fasteners to a lower plate  484  of the embedment tile  480 . The lower plate  484  and the upper plate  482  can both have raised conical domes  486  of similar size, spacing, and shape such that they nest and provide a strong embedment tile that resists damage better than a single plate surface of an embedment tile. As seen in  FIG. 28 , the lower plate  484  can have embossed domes  488  that are not ribbed because the domes without ribs are not exposed and are cheaper to manufacture, yet are able to nest with the embossed domes  486  of the upper plate  482 , although the domes  488  could also have ribs  487  like those on the upper plate  482  domes  486 . 
     The upper plate  482  and the lower plate  484  can be joined together by nuts  490  and bolts  492  ( FIG. 30 ), and in particular can be joined with nuts  490  secured to the lower plate  484  and bolts  492  that extend through holes  508  (such as seen in  FIG. 25 ) in the upper plate  492  and are threaded into the nuts  490 . The nuts  490  are preferably closed at the bottom to prevent concrete and other debris from entering the nut  490  ( FIG. 29 ). 
     The embedment tile  480  can be preassembled at a factory and initially installed in the same way a single plate embedment tile is installed, as described above. When the upper plate  482  requires replacement, the bolts  492  are removed, the upper plate  482  is removed, the new upper plate  482  is nested on top of the lower plate  484 , and the bolts (or new bolts)  492  are threaded into nuts  490  attached to or anchored underneath the lower plate  484 . Other types of anchoring systems can also be used to secure the upper plate  482 , such as expandable anchors  497  ( FIG. 29 ) that wedge into cured moldable material under the embedment tile. 
     Alternatively, the double plated embedment tile  480  can be initially installed with only the lower plate  484  and the upper plate  482  added after the lower plate  484  portion is embedded in moldable material and stabilized. Such an installment method reduces the overall weight of the embedment tile for ease of installation. 
     Further, with the upper plate  482  removed, the embedment tile lower plate  484  can include air vents  496  ( FIG. 28 ) to allow air to escape from under the embedment tile  480  during installation. Air vents  496  are particularly useful in the conical domes  488  (as illustrated) of the lower plate  484  because they allow air pockets under the domes  488  to escape and moldable material to fill the undersides of the domes  488  to reinforce the domes  488  from snow plow damage, for example. 
       FIGS. 25 ,  26 , and  27  depict another embodiment of an embedment tile  500  in accordance with the present invention. The embedment tile  500  includes an upper plate  502 , a number of tactile projections  504 , downwardly extending flanges  506 , and anchor holes  508 . The embedment tile upper plate  502  is positioned over a lower embedment tile plate  512 . 
     The upper plate  502  of this and the other embodiments can be made of any suitable material, but is preferably stainless steel of at least  16  gauge, Grade  304 . The upper plate  502  (and  482  above) can also be E-coated and painted for a durable coating. 
     The lower plate  512  (and  482  above) need not be made of stainless steel because it is not as exposed to damage as is the upper plate  502  (and  484 ). Nonetheless, the lower plate  512 / 482  can be any suitable material such as stainless steel, galvannealed steel or mild steel, and any of these can be E-coated for added corrosion resistance. A coating weight of A60 of galvannealing provides adequate protection from snow plow damage, but other weights may be used depending upon subsequent manufacturing steps and expected product usage. 
     The tactile projections  504  are shaped to meet or exceed all state and federal design requirements for such tactile surfaces, as explained above in relation to the embedment plates. Preferably, the tactile projections  504  are sized and spaced so that the embedment tile top plate  500  nests onto the lower plate  512 . Alternatively, the embedment tile top plate  500  can rest on top of the lower plate  512  projections  514 . 
     The downwardly extending flanges  506  preferably extend down about 0.500 inches and are formed integrally with the plate  502 . The downwardly extending flanges  506  preferably include slots  511  that function to permit flexibility during installation. The downwardly extending flanges  506  can be a single flange that either completely or only partially surrounds the embedment tile upper plate  500  plate  502 . 
     The anchor holes  508  are preferably formed during manufacture of the embedment tile upper plate  500  by stamping, punching, drilling or other method, but they can be drilled on site where the embedment tile upper plate  500  is to be installed. 
     Also preferably, the embedment tile upper plate  502  is sized to match the size of the lower plate  502 , but this is not absolutely necessary because the embedment tile upper plate  502  can be larger or even smaller than the embedment tile lower plate  512 . The embedment tile lower plate  512  can include any type of moldable material anchor  513 , with those described above in other embodiments being preferred. 
     A method for installing a embedment tile upper plate  500  in accordance with the present invention includes the steps of; forming a flange recess at least partially around a lower plate  512 , placing a embedment tile upper plate  500  over the lower plate  512 , inserting a downwardly extending flange  506  into the flange recess, and anchoring the embedment tile upper plate  500  to cured concrete or asphalt underneath the lower plate  512 . 
     The step of forming a flange recess can include sawing a recess around or at least partially around the lower plate  512 . The step of anchoring the embedment tile top plate  500  to the cured moldable material underneath the lower plate  512  can include the steps of drilling holes into the cured moldable material and inserting anchors in the holes. Preferably, the anchors include an AVK nut that is enclosed at its bottom end that is pounded into a drilled hole and a bolt  492  that is threaded into the AVK nut  490 . Other anchor types can also be used. AVK fasteners are available from AVK Industrial Products located at 25323 Rye Canyon Road, Valencia, Calif. 91355. 
       FIG. 28  illustrates alternate shape embodiments of embedment tiles in accordance with the present invention. Rectangular tiles  550  and wedge-shaped tiles  552  are used in combination to create a generally arc-shaped tactile surface to accommodate a curved curb  556 . Preferably, the rectangular tiles  550  are about 48 inches by about 24 inches, and the wedge-shaped tiles  552  are about 24 inches long by about 2 inches wide at the narrow end, and about 8 inches wide at the widest end. Other tile shapes and sizes can be used in the present invention. 
     Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the scope of the claims should not be limited to the description of the preferred versions contained herein.