RELATED APPLICATION This application is a continuation-in-part of copending application of Serial No. 07/705,124, filed May 24, 1991.

FIELD OF INVENTION This invention relates to a tactile edge-warning panel particularly suited for application to train platform edges for providing a safe, effective means of warning visually- handicapped persons when approaching the platform edge. This invention also serves as a safety feature which keeps fully sighted people away from the platform edge.

BACKGROUND OF INVENTION

There are many instances in which visually handicapped persons need to be warned of their approach to a dangerous area. For example, it is critical in public areas to warn those persons of their proximity to uneven surface areas. Some examples of areas requiring such warning include train platform edges and sidewalk curbs, especially in the vicinity of cross-walks where the warning can also indicate the presence of a cross-walk and curb cuts.

There have been numerous attempts to provide such warning to visually handicapped persons. Most of those attempts employ tactile warning, often times along with some visual warning to which partially-sighted visually handicapped persons may be able to respond. Most of the tactile warning systems employ relatively small tiles having some type of uneven surface which the visually-handicapped person can detect with a cane or his or her feet. One such

device is disclosed in U.S. Patent No. 4,715,743. That device comprises tiles made of a flat plate of a flexible polymer material with a number of raised bumps formed of the same material and projecting from the surface. These tiles must be set in concrete or mortar in the areas in which warning is desired. In existing stations, concrete must be removed in order to create a setting bed for the tile and allow for a level installation. Accordingly, the tiles are difficult and expensive to install. Further, the area in which the tiles are installed may not be used by the public until the mortar is set, which can be a problem in areas such as train stations which are typically operated 24 hours a day.

Since these solutions require a large number of tiles, each having four edges, there are innumerable tile edges in any area of tiles, all of which need to be aligned to present a flat, even tile area which will not cause pedestrians to stumble or trip. In addition, any one of those tile edges may be caught and lifted partially or fully by pedestrian traffic, or more likely, by machinery used to clean the surface. Lifting is especially a problem in outdoor areas in the northern latitudes in which the surfaces must be cleared of snow during the winter; the snow clearing shovels or tractors can easily catch a tile edge and lift the tile, necessitating immediate replacement to prevent the creation of a dangerous hazard to both visually impaired and normally sighted individuals. Because tiles are not mechanically fastened, the expansion of materials due to changes in the weather causes the tiles to frequently delaminate from their bonding agents. In outdoor applications, the tiles tend to bleach rapidly, thereby losing some of their visual impact. Accordingly, the tile tactile edge-warning systems have a number of drawbacks which have prevented them from being ideal solutions to the problem.

SUMMARY OF INVENTION

It is therefore an object of this invention to provide a tactile edge-warning system which presents a uniform, durable surface which is both non-slip and readily detectable by a visually impaired person.

It is a further object of this invention to provide such a system in which the tactile edge-warning device is quickly and easily anchored to the surface requiring tactile warning.

It is a further object of this invention to provide such a system in which the tactile edge-warning device may not easily be lifted from the surface to which it is anchored.

It is a further object of this invention to provide such a system in which most edge warning applications can be accomplished with large, unitary structures which minimize the number of hazardous edge intersection areas.

It is a further object of this invention to provide such a system in which the strip is compliant, resilient, and is sound-deadened. The non-slip texture provides an effective contrast in sound-on-cane contact between the warning surface and adjacent areas when a cane is slid across the surface.

It is a further object of this invention to provide a wear-resistant surface which can be easily seen and easily maintained.

It is a further object of this invention to provide a surface which provides a distinct visual contrast with its surrounding area.

This invention features a tactile edge-warning panel system including a panel or strip that may be sheet-metal or a molded material (such as an acrylic resin) for fixing to a surface, a series of projections formed in the strip to present an uneven surface for tactile feedback, a roughened coating on the uneven surface to inhibit slipping, and an angled strip edge portion or return for anchoring the strip

edge into the surface to inhibit strip lifting. Preferably, the strip is made of a pregalvanized steel or other material such as stainless steel or aluminum. Sixteen-gauge pregalvanized steel has been found to be an ideal material. The strip preferably includes a series of holes through the strip along its edges to allow passage of surface fasteners. The strip may include the angled edge portions on more than one edge to allow firm anchoring of the exposed edges of the strip to prevent its lifting and also provide a "cleaner" finish. Preferably, the strip edge is angled at approximately 90° to the strip and projects 3/16" to 1/2" below the strip when being set into a sawcut. The strip edge can project up to 2 1/2" below the strip when mounted against a platform edge or visible edge.

The roughened surface coating may include a paint or an epoxy-based substance having therein a hard filler material for creating the roughened coating. The edges may be anchored into the surface by a polyurethane-based sealant or a two-component traffic loop sealant, dependent upon the substrate type.

The system may include a filler sheet between the strip and the surface to which it is applied. The filler may be compliant to help match the uneven surfaces, to provide a compliant feel to the strip for cushioning hard surfaces, and to provide a distinctly different sound from surrounding substrate when impacted by a sweeping cane, tapping cane, foot, or seeing eye dog. An expansion joint may be included to inhibit abrupt jutting edges produced by heaving at joints between strips.

The strip projections may include truncated, tapered bumps or elongated, linear bumps or other configurations. The projections in one embodiment are formed in a regular pattern. Alternatively, the projections may be spaced closer

together toward one end of the strip than toward the opposite edge to provide tactile strip-position warning.

DISCLOSURE OF PREFERRED EMBODIMENT

Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:

Fig. 1 is an axonometric view of a tactile edge-warning panel according to this invention;

Fig. 2 is an end view of the panel of Fig. 1 detailing the raised projections and the angled strip edge;

Fig. 2A is a similar view showing a panel return covering a platform edge;

Fig. 3A is a cross sectional view of a tactile edge warning panel according to this invention anchored to a platform edge;

Fig. 3B is a detailed cross section of the panel edge of Fig. 3A embedded in the platform;

Fig. 4A and 4B are end and top views of an expansion joint for use on asphalt platform applications;

Figs. 4C and 4D are similar views for an alternative expansion joint;

Fig. 5 is an axonometric view of an alternative dimple pattern;

Fig. 6 is an axonometric view of an alternative dimple shape;

Fig. 7 is a cross-section through a dimple of Fig. 5;

Fig. 8 is a cross-section through an elongated, linear dimple;

Fig. 9 is a view of another dimple design; and

Fig. 10 is a view of electrical grounding of panels according to this invention;

There is shown in Fig. 1 tactile edge-warning panel 10 according to this invention. Panel 10 is made from a strip of sheet metal. Preferably, galvanized steel is employed; it has been found that 16 gauge pregalvanized steel accomplishes a strip which is stiff and tough, yet light enough to allow the installation of long strips by only one or two people. Aluminium (easier handling due to lighter weight) or stainless steel (maximum corrosion resistance) may also be used. Panel 10 includes angled edge 16 which helps to anchor the panel as described below. The top surface of panel 10 includes a number of raised projections 14, only some of which are shown, to present an uneven surface for tactile feedback. Further included are a series of punched oval holes 15 to allow for expansion and contraction along all four edges and along the interior portion of panel 10 to allow it to be anchored to surfaces requiring tactile warning. The panel may be anchored to wooden surfaces by screws, and to concrete and asphalt surfaces with specialized fastening devices known in the art.

Panel 10 is shown in end view in Fig. 2 , in which it can be seen that angled edge 16 is preferably bent at a 90° angle to panel 10. The edge may extend 3/16" to 1/2". The other edge may be beveled as shown to minimize sharp edges and reduce tripping hazard. A 2" return can be added to protect the platform edge and better anchor the tactile panel. Projections 14 are preferably formed by deforming the sheet metal material so that the entire panel can be made from a single piece of metal. This arrangement allows a tactile edge-warning strip according to this invention to be made of virtually any length and width to fit a desired application. For example, many train platforms require tactile warning 24" wide along the length of the platform. This may be accomplished in the present invention by

employing a sheet metal strip up to 28" wide which has projections 14 formed therein, and then one or more edges bent in a press brake to create angled strip edge or edges such as edge 16. Hazardous vehicular areas (including curb cuts) require a tactile warning system which is 36" wide. The only limitation to the size and shape of the strip is the ability to finish the strip and transport, carry and install the strip. Accordingly, many train platforms can be protected with one or only a few strips placed end to end. As a result, there are very few edges on the platform which are subject to lifting and the consequent presentation of an uneven surface which can cause stumbling or tripping, even of sighted persons.

The upper surface of panel 10 may be painted or coated with a rough coating 19, Fig. 2, to inhibit slipping and aid in detection by the visually impaired. In one embodiment, the coating is an epoxy-based liquid material which hardens after application by painting or spraying, and which includes a relatively high solids content for providing a non-slip surface. The panel may need to be prepared by blasting and then priming. In another embodiment, a non-skid paint may be used. Such may not require a primer coat. These paints preferably have fast curing times so that the panels can be stripped and re-painted in place during platform shutdown times (approximately 6 hours) . The material is preferably colored a bright color so that partially/fully-sighted persons may detect the contrast with the adjacent surroundings and in this manner confirm the fact that they are on or approaching a tactile panel. Fading of coatings by sunlight may be inhibited by applying a top coat such as a urethane with pigmented acrylic-base sealer. One material which has been found suitable for coating 19 is Trac Guard M.P.200 rust inhibitive epoxy metal primer and Trac Guard

HD302 heavy duty non-slip coating by Trac-Guard (A Division of Spray Lat Corp.), Mt. Vernon, New York; or primer 5C and finish coat AS-550 made by American Safety Technologies, Inc. , Roseland, New Jersey.

A preferred embodiment of the shape and pattern of projections 14, Figs. 1 and 2, shows that projections 14 are round tapered projections having a relatively flat top section 18. Preferably, projections 14 are formed in a number of rows 20, 22 and 24, with alternating rows, 20 and 22, identical, interspersed with row 24 of projections offset to create the regular offset pattern shown. Alternatively, the size, shape and/or spacing of the projections may be altered as desired. For example, the projections may be made closer together toward one edge of the strip to indicate that the strip edge is being approached. Such an embodiment may be useful in a train platform for warning the visually-handicapped person when the very edge of the platform is being approached. Alternatively, these projections, or projections of any other shape, such as elongated, linear projections, may be formed into patterns which indicate a direction or other state to the visually-handicapped person.

Panel 200, Fig. 2A, includes 2" return portion 201 disposed over the track-side edge of platform 34a, and anchored therein, to both cover the platform corner and firmly anchor the panel edge.

Fig. 3A illustrates the application of panel 10 to concrete train platform 34 leading to track bed 32. It has been found generally useful to apply a thin membrane between platform 34 and panel 10. Membrane 29 may be a 1/16" EPDM membrane for wood or concrete application or polyethylene or polypropylene rubberized asphalt sheeting for asphalt, wood, or concrete applications. EPDM may not be used in asphalt

due to compatibility problems with the substrate. The membrane 29 is preferably glued to the underside of the panel and provides a cushioned, bulky feel on hard surfaces that is more comfortable. Also, the compliant membrane helps to level older, uneven platforms, reducing voids and tactile panel springiness. This also decreases the amount of platform surface levelling preparation required before installation. Also, membrane 29 deadens the sound of strip 10, thereby providing a clear audio signal to a visually impaired person that a dangerous area is nearby, especially when panel 10 is tapped with a cane.

Panel 10 may be held onto platform 34 by concrete nails such as Zinc-Spike or Zamac Nailin made by Rawl Plug Co., of New Rochelle, New York. Tamper-proof stainless steel screws may be used for wooden platforms. If an aluminum tactile panel is used on concrete platform 34, a coat of bituminous paint or rubberized asphalt sheeting may be applied in order to inhibit galvanic action. The panel may also be set in fresh concrete. Studs may be added to the back of the strip in this case to help anchor the strip. For application to asphalt, speed-lock toggle bolt assemblies with Louie loops, also available from the Rawl Plug Co., may be used. Adhesives may be used in conjunction with mechanical fasteners. Platform 34 is prepared by making a saw cut 48 therein, Fig. 3B, for accepting angled edge portion 16 of strip 10 so that a raw edge of the strip is not presented on the platform surface to decrease any tripping hazard, and also to inhibit the lifting of the strip from the platform, especially by mechanical devices used for cleaning or shovelling the platform which can easily slide under an exposed edge and lift the tactile warning device. Saw cut 48 is filled with caulking 50 for anchoring edge 16 therein. Caulk 50, for wood and concrete platforms, is preferably a polyurethane based adhesive such as Sikaflex-IA which firmly

anchors, in conjunction with nails 28, strip 10 to platform 34. For asphalt, wood or concrete platforms, Sealex Loop sealant by W.R. Meadows, Inc., may be used. The other edges may also be caulked to eliminate penetration of water or other liquids.

Figs. 4A and 4B detail an expansion joint that may be used at tactile strip joints especially on asphalt platforms that may have a tendency to heave. Without such an expansion joint, heave may cause a sharp height differential at the joint, presenting a tripping hazard which is especially detrimental for a tactile edge warning strip designed to provide tactile feedback to visually handicapped persons. To eliminate this problem, joint 110 is applied across and underneath of the joint of panels 102 and 104 which are separated by 1/4" expansion joint gap 116. Membranes 106 and 108 are left short of the joint to allow room for expansion joint 110 consisting of interleaved joint members 112 and 114, themselves separated by a 1/4" expansion joint space 118. As best shown in Fig. 4B, members 112 and 114 have a pattern of interwoven fingers. Joint 110 changes any heave at the intersection of panels 102 and 104 from a sharp point to a curved or bowed area, thereby presenting far less of a tripping hazard.

Alternative expansion joint 200, Figs. 4C and 4D, comprises metal plate 216 welded to the underside of one of panels 212 and 214 before installation. Panels 212 and 214 have lower, compliant membranes 211 and 215, respectively, as described above. When installed, 1/4" gap 213 is left between panels 212 and 214, and fasteners are passed through holes such as holes 218 and 220. Plate 216 thus also provides electrical continuity between panels 214 and 216 to facilitate electrical grounding, described below.

Fig. 5 details pattern 0 of dimples on strip 10a that may be used as a guide. Other shapes of dimples may also be used, such as octagonal-sided dimples 62, Figs. 6 and 7, and elongated linear dimples, Fig. 8. The dimples may also have a very slightly truncated, or non-truncated, conical shape as shown in Fig. 9.

Fig. 10 illustrates electrical grounding of the panels installed on a platform. Panel 250 on the edge of platform 252 above track bed 254 is electrically connected to grounding rod 256 driven into bed 254 by wire 258. Joints such as expansion joint 210, Fig. 4C, provide electrical continuity amongst all the panels so that the entire platform area is sufficiently grounded.

Other possible uses of the panel are for floor plates providing a non-slip surface to avoid removal of contaminated flooring, which cannot be painted directly with a non-slip paint, for example in diesel maintenance facilities. Also, the panel may be used as a threshold upon entering a train or transit vehicle in order to avoid slipping hazard. The panels may be used to provide a non-slip flooring for marine applications.

The tactile edge-warning panel of this invention may also be used for other applications where tactile warning is needed, or for applications in which hard, non-slip surfaces are desired. For example, the panel may be used for curb cuts at sidewalks and platforms and as stair treads or for landings at the top or bottom of the stairs. The edge warning panel may also be incorporated into retractable train platforms. Other uses are for speed bumps/warning strips in roadways, or as raised areas to help cars stop at intersections where icing is a problem.

The tactile panel member of this invention may also be formed of a solidifiable material, such as a polymer, by

casting or molding. Acrylic resins such as Silikal R68 available from Silikal North America, Inc. , of Stratford, Connecticut, are tough, durable, and able to withstand temperature extremes: these materials are thus well suited for application to public places that see heavy foot or vehicle traffic, and which may be exposed to the elements. This material can be cast in any size and shape and then may be painted. Alternatively, pigments and solids (for roughening) may be added to the liquid that is cast so the color and roughness extend through the entire panel thickness.

These cast panels also have some natural compliance, and so can be used on contoured surfaces such as curb cuts. Also, they are installable with adhesives, although some mechanical fasteners may also be used. Because these panels are cast, they can be repaired in situ.

Although specific features of the invention are shown in some drawings and not others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention.

Other embodiments will occur to those skilled in the art and are within the following claims: What is claimed is: