Abstract:
A visual highlight accessory for attachment to highway guardrails has a paint coating and a clear varnish overcoating with mica particles for making the visual highlight accessory and the guardrail on which the visual highlight accessory is mounted readily visible to persons in vehicles travelling along a highway along which the visual highlight accessory borders. The visual highlight accessory has orifices corresponding to orifices in the guardrails to facilitate mounting of the visual highlight accessory on a guardrail.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of Chilean utility model application No. 01052 filed Sep. 30, 2010. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to guardrails, namely highway guardrails, and more particularly apparatus for making guardrails readily noticeable to drivers of motor vehicles on the highways and roadways having guardrails bordering the sides and medians between lanes of traffic on highways and roadways. 
     2. Description of the Prior Art 
     Guardrails bordering highways and roadways are well known in the United States and throughout the world. Highways are usually bordered with continuous, horizontal metal guardrails, having guardrail beams attached to regularly spaced vertical posts spaced at equal distances along the highways and roadways, and anchored to the ground. (Highways and roadways will hereinafter be defined as “highways.”) The continuous guardrail beams are generally attached to the vertically-anchored posts for holding one or more horizontal guardrail beams between the vertical posts. 
     The horizontal guardrail beam is generally composed of a continuous horizontal rail or beam which may have a double-wave shape, generally referred to as a W-beam made from standard heavy gauge metal. Each guardrail beam usually has at least two folds to provide a typical W-beam cross section. A series of post bolt holes and splice bolt slots are included in the guardrail beams so that they can be used interchangeably with existing guardrail systems. W-beam guardrails very often comply with the American Association of State Highway Transportation Official (AASHTO) Designation M180-89. Designation 180-89 Class Type A specifies that the overall length of the W-beam guardrail is respectively 4.318 meters with an effective length 4.0 meters or 4.128 meters with an effective length of 3.81 meters; the uncoated thickness for both lengths is 2.67 mm; and the weight is respectively 46 kg or 44 kg. Highway guardrails have end treatments. Guardrail beams are conventionally made by roll-forming methods using steel alloy materials. The W-beam guardrail is galvanized and coated with a zinc covering to avoid corrosion and increase the life of the guardrail. AASHTO Designation M180-89 for galvanizing has a minimum single-spot test of 1,100 g/m 2  (3.603 oz/ft 2 ) and a minimum triple-spot test of 1,220 g/m 2  (4.003 oz/ft 2 ). A requirement for galvanizing is to be in accordance with ASTM A123. 
     A serious and very common problem with guardrails is that they are not highly visible to drivers of motor vehicles on the highways which are bordered by the guardrails due in part to the color of the guardrails, to deterioration of the guardrails and to the large number of other motor vehicles that are close to any particular motor vehicle traveling on the highway. The visibility of guardrails is very important for both daytime and night-time driving, since the guardrails should be readily apparent during the day under ambient light, and at night from the reflection of headlights and sometimes street lamps along the highway. Another problem with the visibility of guardrails is that motor vehicles travel very fast, particularly along long, slightly curved highways, requiring each driver to concentrate on the highway itself rather than on the guardrails. Furthermore, guardrails tend to be covered with dirt and dust due in part to the fast moving vehicles traveling along the highways and due in part to the weather, and there is little or no cleaning of the guardrails where they are used. Support posts are provided for supporting and maintaining the highway guardrails horizontally along the highway. The posts are anchored to the ground, and may be fabricated from metal, wood or a combination of metal and wood. One often-used requirement for metal posts is that they meet the requirements of ASTM A36/A36M. 
     There are various techniques which are presently being used to enhance the visibility of guardrails. These generally involve using readily visible paint or fluorescent adhesive tapes that are put on the guardrails after the guardrail system has been installed. However, it has been found in practice that these techniques do not have a sufficiently long duration of being effective, they are not as visible as would be desired, and many accidents have occurred with lateral or frontal impacts of motor vehicles. Some presently available products include an I-Beam Reflector/Protector from HSS Traffic Control Products, Fort Wayne, Ind., for attachment to guardrails, different types of reflecting devices for being attached to guardrail systems and types of reflective tapes. One reflective sheet is 3M™ Diamond Grade™ Fluorescent Sheeting, 3M Corporation, St. Paul, Minn. However, these have not proven effective. The conventional techniques of rendering guardrails more apparent to drivers are economically inefficient, particularly with installed guardrail systems, because they require an intensive maintenance program with high labor costs and the expense of replacement materials in order to keep the guardrails visible. It has recently been stated: “Chronic lack of research is highlighted with particular reference to visibility and its inadequate treatment in design standards.” Douglas Stewart, Civil Engineering 160, pp. 131-136. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a product for improving the visibility of guardrails so that they are readily observable by drivers of motor vehicles along highways which are bordered by the guardrails. 
     Another object of the present invention is to provide an improved product for rendering guardrails readily apparent to drivers of motor vehicles on highways or roadways bordered by the guardrails which can be installed at relatively low expense. 
     It is still another object of the present invention to provide a product for improving the visibility of highway guardrails including a product which is easy to transport from a storage facility to the respective highways where the guardrails are to be installed. 
     Another important object of the present invention is to provide a product for enhancing the visibility of highway guardrails to drivers of motor vehicles traveling along highways bordered by the guardrails, which product is highly reflective and works well both at nighttime and during the day. 
     It is also an object of the present invention to provide a covering for a visual highlight accessory for highway guardrails which is more visible to drivers of motor vehicles along highways bordered by the guardrails than are presently available using paints and other coverings. 
     A still further object of the present invention is to provide a visual highlight accessory to be applied to guardrail systems which is made of a product which would not deteriorate in the environment and can be applied using inexpensive application techniques. 
     It is still another object of the present invention to provide a guardrail visibility system which is readily observable by drivers of motor vehicles along highways bordered by the guardrails at all angles of perception, rendering the guardrail beams readily visible as drivers pass continuously placed guardrails. 
     A yet further object of the present invention is to provide product for enhancing the visibility of guardrail beams which does not detrimentally change the shape of the respective guardrail beams. 
     Another object is to provide a visual highlight accessory for guardrail beams which covers the guardrails and which has the same length as the guardrails and has holes the same as the holes in the guardrails so that the same bolts or other fastener can be used for attaching the respective accessories to the guardrails as are used for attaching the guardrails to each other in an overlapping means or by means of a connector as is well known in the art and widely practiced in the United States and around the world. 
     It is also an object of the present invention to provide a covering for guardrail beams in the form of an improved paint which not only improves the visual brightness of the guardrail beams, but further keeps the base color of the guardrail beam unchanged while increasing the reflectability of the paint. 
     A basic object of the invention is to prevent vehicular accidents between vehicles and guardrails and to avoid injury and save lives of persons in the vehicles. 
     A general object of the present invention is to provide an improved system for enhancing the visibility of guardrails to drivers of motor vehicles traveling along the highways bordered by the guardrails, which system is effective in operation, and efficient to install and maintain. 
     These and other objects of the present invention should be apparent to those skilled in the art from the description to follow and from the appended claims. 
     The invention in its preferred form includes, in part, a covering including a brightly colored paint on top of which is coated with clear, non-color or a transparent varnish having fine mica particles dispersed therein for providing a strong reflective effect on the surface on which it is coated. The paint and varnish are preferably made from a polyester resin, and the fine mica particles result from an organic pigmentation. 
     Another aspect of the present invention is a visual highlight accessory which is secured to a highway guardrail, and the accessory can be made from galvanized steel sheet, aluminum or polyvinyl chloride (PVC), the latter being shaped as desired using an extrusion machine. The visual highlight accessory is preferably first coated with the paint, preferably bright yellow paint. A coating compound made with a mixture of clear varnish and mica is applied to the accessory with a coater machine. The visual highlight accessory is then placed in an oven to dry with ultraviolet lamps. The visual highlight accessory is preferably very smooth to reduce or eliminate any cleaning thereof. 
     Galvanized steel sheet and aluminum are the preferred materials since they allow for easy shaping using a roll-forming process, are easy to handle, and provide a long-lasting attachment when the metal accessory is mounted on an existing respective highway guardrail beam. 
     If the visual highlight accessory is made from PVC as described above, the PVC has a corona treatment for opening the pores on the PVC in order to achieve the stronger adherence of the varnish mixed with mica. 
     A highway guardrail system, as mentioned above, includes horizontal guardrail beams attached to vertical posts anchored to the ground. The horizontal guardrail beams as installed are fixed to the vertical posts with bolts and nuts which are generally the same for the respective highway guardrail systems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a portion of the highway guardrail system employing W-beam guardrails fixed to vertical posts; 
         FIG. 2  is a cross-sectional view of a W-beam guardrails shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of a horizontal W-beam guardrail mounted on a vertical post; 
         FIG. 4  is a cross-sectional view of a W-beam guardrail having a visual highlight accessory according to the preferred embodiment of the invention mounted thereon; 
         FIG. 5  is a cross-sectional view of a W-beam guardrail with a pair of visual highlight accessories attached thereto according to the preferred embodiment of the invention; 
         FIG. 6  is an isometric view of a W-beam guardrail having a visual highlight accessory according to a preferred embodiment of the invention about to be attached thereto; 
         FIG. 7  is similar to that of  FIG. 6  showing a pair of visual highlight accessories about to be attached to a W-beam guardrail; 
         FIG. 8  is an isometric view of a W-beam guardrail with a visual highlight accessory according to a preferred embodiment of the invention in position for being assembled, and a set of fins having reflective tape attached thereto with a detailed enlargement of a part of the view; 
         FIG. 9  is a front view of a visual highlight accessory according to the preferred embodiment of the invention in its painted condition, prior to being folded to the W-shape; and 
         FIG. 10  is a front view of a visual highlight accessory as shown in  FIG. 9  after having been bent or folded. 
         FIG. 11  is a schematic view of a machine line for manufacturing a visual highlight accessory according to a preferred embodiment of the invention. 
         FIG. 12  is an exploded view of a guardrail assembly with which the present invention could be used. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , a guardrail assembly  10  is shown. Guardrail assembly  10  includes a pair of W-beam guardrails  1  which are connected together by a corner brace  3  and mounted on a pair of spaced vertical posts  2  which are anchored to the ground. One of W-beam guardrails  1  extends between the corner brace  3  and another brace  5  which are affixed to another anchored post  2  and could be attached to an end anchor treatment. W-beam guardrail  1  is shown as having a double-wave shape with an upper crown  7  and a lower crown  9 , which are connected together by an integral transition component  11 . 
     Another guardrail assembly  100  is shown for a slightly different guardrail assembly with which the present invention can be used, which varies slightly from guardrail assembly  10  shown in  FIG. 1 . Guardrail assembly  100  includes a set of W-beam guardrails  101  having a set of holes  103  through which bolts extend for attachment to other guardrails  101  in a succession of guardrails  101 . The bolts extending through holes  103  would normally be held in place by a set of nuts. Oval splice bolt slots  105  each receive a bolt  107  which extends through a rectangular washer  109  and then through slot  105  for attachment to a vertical post  2 , which in this case includes a separator  111 . Separator  111  is a modular unit which is composed of a pair of parallel flanges  113  lying in general planes which are perpendicular to vertical post  2  and to W-beam guardrail  101  when it is attached thereto. Parallel flanges  113  are attached to a separator plate  115  which is perpendicular to flanges  113  and to W-beam guardrail  37 . A washer  117  is disposed between flanges  113  and parallel to washer  109  for receiving bolt  107  passing through washer  109  and one of holes  103  to attach W-beam guardrail  101  to post  2 . Separator  111  has holes for receiving one of bolts  119  which extend through one of three vertically oriented oval splice bolt slots  121 . Guardrail system  100  is oriented as shown along the border of a highway whose direction of vehicle flow is shown by the arrow  123 . The foregoing is intended to provide a better understanding of a guardrail system with which a visual highlight accessory  16  would be used in an actual operating environment. 
     Referring next to  FIG. 2 , a cross-sectional view of W-beam guardrail  1  is shown. Upper crown  7  and lower crown  9 , and integral transition component  11  are clearly shown. As mentioned previously, W-beam guardrail  1  could be expected to meet AASHTO Designation M180-89 standards. 
     Turning next to  FIG. 3 , W-beam guardrail system  10  is shown in a side view. W-beam guardrail  1  is shown attached to post  2  by means of brace  3 . This is accomplished by means of one of bolts  4  which extend through an oval hole  12  in transition component  11  of W-beam guardrail  1 , and a brace hole  14  in brace  3 . 
     Referring next to  FIG. 4 , W-beam guardrail  1  is shown having its upper crown  7 , lower crown  9  and transition component  11 . Shown in an exploded view is a visual highlight accessory  16  forming part of the invention, which is positioned to be attached to upper crown  7 . Accessory  16  is configured the same as upper crown  7  so that it can be attached to upper crown  7  with the two pieces being substantially in contact. Likewise, referring to  FIG. 5 , a pair of accessories  16  are shown as being ready to be attached to upper crown  7  and lower crown  9  of W-beam guardrail  1 . 
     Referring next to  FIGS. 6 and 7 , W-beam guardrail  1  is shown with upper crown  7 , lower crown  9  and transition component  11 . Visual highlight accessory  16  is shown in  FIG. 6  as being ready to be installed on upper crown  7 . W-beam guardrail  1  includes a set of oval splice bolt slots  17  which are disposed one over the other, with two slots  17  in upper crown  7  and two slots  17  in lower crown  9 . It is shown in  FIGS. 6 and 7  that oval splice bolt slots  17  are at both ends of W-beam guardrail  1 . Likewise, accessory  16  has oval slots  18  corresponding to slots  17 . Slots  17  and  18  are each dimensioned so that they can receive the same bolts, so there is no need for a separate set of bolts for each of slots  17  and  18 . (If slots  17  and  18  were circles, they would have the same diameter.) When visual highlight assembly  16  is fitted against upper crown  7  so that slots  17  are in line with oval slots  18 , a bolt can be inserted into the respective slots  17  and  18  and a nut applied to the respective bolt so that visual highlight assembly  16  is held fast against upper crown  7  of W-beam guardrail  1 . The same situation is true for visual highlight assembly  16  which is fitted over lower crown  9  of W-beam guardrail  1 . As shown in  FIG. 10 , slot  17  is elongated in the vertical direction, and this permits a slight amount of vertical movement between accessory  16  on W-beam guardrail  1  without affecting its performance. 
     As shown in  FIGS. 6 and 7 , visual highlight accessory  16  is of the same length as the length of W-beam guardrail  1 , has holes (which could be slots) of the same diameter as the holes of guardrail  1  (or at least the same shortest cross dimension if slots  17  and  18  are elongated) and the same distance between the holes to enable them to receive the same bolts or other fasteners. Since the same nuts and bolts would preferably be used to install the respective accessories  16  to W-beam guardrails  1 , this would simplify obtaining the respective parts and installing them. 
     Turning to  FIG. 8 , W-beam guardrail  1  is depicted with visual highlight assembly  16  in position to be attached thereto. In addition to the bright color and reflectivity which is part of visual highlight accessory  16  as discussed below, a set of fins  20  are attached to W-beam guardrail  1  which extend from respective blades  22  discussed below. Referring to the enlarged detail shown in  FIG. 8 , each fin  20  preferably has a length 1 of preferably 70 mm, a height of 60 mm and a thickness of preferably 1 mm. Attached to the face of each fin  20  is a reflecting tape  24 . With reference to the detailed enlargement incorporated in  FIG. 8 , it can be seen that there is a fold  26  which need be only 10°. Fold  26  adds tension to fin  20  to provide resistance to wind. Reflecting tape  24  with fold  26  reflects vehicle headlights and street lights to assist in alerting vehicle drivers of the presence of guardrail system  1 . Blades  22 , extending from the base of respective fins  20 , have a length of preferably 60 mm rather than 50 mm (the latter being the height of slit  23 ), and are placed on the inside of accessory  16  facing toward the outside of accessory  16 . Faces  21  extend outwardly as shown. The wider blade  22  makes it difficult to remove fin  20  from accessory  16  and helps to avoid theft. Thefts should be difficult to occur because fins  20  are not held in place by bolts (which also would add expense), but by the increased height of blades  22 . Slits have been made which have a length of 51 mm and a width of 1.5 mm, and fins  20  have a length of 50 mm for entering slits  23 , and a gauge of 1.0 mm to fit through the 1.5 mm width. Each fin  20  is bent 90° to form blade  22  in a press in a manufacturing shop. Blade  20  is located on the inside of slit  23  to make it difficult to remove, thus preventing or at least making theft of fins  20  more difficult. Each fin  20  is installed from behind accessory  16  (on the side to face guardrail  16 ) before visual highlight accessory  16  is installed on guardrail  1 . Face  21 , blade  22  and fold  26  are each flat. Blade  22  may be provided with a curve corresponding to the curve of the back of visual highlight accessory  16  to provide intimate contact between blade  22  and accessory  16  for a more positive seating of fin  20  against accessory  16 . Reflector tape  24  is placed on fin  20  in a shop and not on site. Reflecting tape  24  could, for example, be 3M™ Diamond Grade™ Fluorescent Sheeting, discussed earlier 
       FIG. 9  shows visual highlight accessory  16  prior to being bent or folded. Oval splice bolt slots  17  are visible. Their dimensions have been found effective if their longest length is 52 mm and their width is 1.5 mm. These slots can advantageously be made with an eccentric press. It has been found effective if the length of each visual highlight accessory  16  is 4318 mm, and their width is 200 mm, as is each crown  7  and  9  of W-beam guardrail  1 . 
     Guardrails  1  could overlap each other, as could accessories  16 . Each accessory  16  is preferably painted with a bright color, especially with a base yellow paint that gives high reflectivity to vehicle headlights and street lights. A particularly good paint is called Yellow Traffic Ral 1023 due to its brightness and its ability to remain effective and last in the exterior for a long time, oftentimes 15 years or more. Yellow Traffic Ral 1023 is available for example from Columbia Coatings, Columbia, Tenn. This paint is much better than conventional paints which may only last for two years. Yellow Traffic Ral 1023 is an effective reflective highlighter at night, in fog and in snow, especially when there is a layer of clear varnish and mica. 
     When accessory  16  is made of metal, it is advantageous if its surface is smooth and free of dust. This makes the yellow paint with reflective material more effective. If the accessory  16  is made from PVC, the color comes out directly from the extrusion manufacturing process. 
     Varnish is poured into a drum with which mica particles are mixed. The varnish is preferably clear. The varnish and mica combination is put in a coater machine, and the previously painted accessory  16  is passed through the coater machine, and through an oven with UV lamps for drying the varnish. A particularly effective varnish is Duranar® fluoropolymer coil coating. The latter coating is a combination of a PPG proprietary resin and pigment technologies with 70% of the resin system being fluoropolymer base resins. This coating is highly resistant to chalking, fading, chipping and peeling when properly applied. Duranar® coatings are available from PPG Industries, Inc., 151 Colfax Street, Springdale, Pa. 15144. Another effective coating is a Truform ZT polyester coil coating which is designed for one or two-coat application on aluminum or steel. Truform ZT coil coatings offer good surface hardness as well as excellent flexibility and resistance to metal marking, marring and staining. They also can be obtained from PPG Industries, Inc. at the address noted above. 
     A preferred manufacturing operation and machine line for making visual highlight accessory will now be described with reference to  FIG. 11  showing a machine line  30  schematically. A coil  32  of galvanized steel sheet  34  having been painted with yellow traffic paint as described earlier is positioned on an uncoiler  36 . Galvanized steel sheet  34  proceeds through a coater  38 , which coats sheet  34  with a mixture of clear varnish with mica particles as also discussed above. Coated sheet  34  proceeds through a UV oven  40  for curing the varnish with mica particles thereon. Cured sheet  34  then progresses to a press  42 , which punches the required holes in the flat sheet  44 . In the example discussed above, there would be four holes  17  and  23  (two of each) punched in sheet  34 . Sheet  34  then proceeds to a roll former  44  which rolls sheet  34  so that it has the configuration of the guardrail to which the visual highlight accessory is to be attached. If the guardrail is the W-beam guardrail  1  discussed above with two crowns  7  and  9  thereon, sheet  34  would be rolled in roll former  44  to have the same shape as crowns  7  and  9 . Shaped sheet  34  then proceeds through a cutting press  46  which cuts shaped sheet  34  into pieces having the desired length, which could be the same length as the horizontal components of guardrail  1 . Finally, the foregoing pieces are stacked in a panel stacker  48 , which does not require workers to manually stack the pieces. The pieces could be strapped together for shipment. 
     The invention has been described in detail with particular reference to the preferred embodiments, but variations and modifications may occur to those skilled in the art from the preceding description and from the appended claims.