Abstract:
A roadway marker is formed from a forged longitudinally extending unitary body having an upper surface and a bottom surface from which extent two rooting members in a direction away from the bottom surface, the upper surface of the elongated body respectively define inclined ramps each extending from a respective end of the longitudinally extending body to a centrally elevated bridging area, the ramps defining recesses in which is mounted reflective media. The rooting pins are secured in holes drilled at an acute angle in the pavement such that when the rooting pins are mounted into the holes drilled in the pavement after an adhesive has been placed in the holes, resilient clips mounted on the rooting pins create an interference fit with the wall of each of the two drilled holes to secure the roadway marker to the pavement.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Not applicable. 
       FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO SEQUENCE LISTING 
       [0003]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Field of the Invention 
         [0005]    The present invention is related to road imbedded traffic lane markers located in or along a road or highway in such a manner that beams of light from headlights of an approaching vehicle will be reflected backwards to heighten the awareness of the vehicle&#39;s driver such that the center of a road or position of a driving lane is readily distinguishable to the driver and assists the driver in determining whether it is safe to pass a vehicle or to change from lane to adjacent lane. 
         [0006]    2. Description of Related Prior Art 
         [0007]    Traffic markers are installed in roadways for the purpose of providing positive visual delineation or identification of various traffic lanes particularly at night, and especially during rainy or foggy conditions. This is particularly true on roads with a dark surface, and on rainy nights when illuminations from headlights appear to be absorbed by the dark roadway. Although traffic lanes are generally defined by lines painted on the pavement, in wet weather, these lines can easily become imperceptible because of the deflection of the vehicles&#39; headlight beams away from their source, rough road conditions, or the vehicle&#39;s driver unfamiliarity with the road traveled. 
         [0008]    In order to eliminate these dangerous conditions, many road markers today incorporate reflectors with reflective surfaces mounted to project above the water residue covering the road surface. The reflective elements are generally accompanied by a metal road marker base that is permanently mounted with an adhesive in the road surface and encapsulates the plastic reflectors to protect them from damage due to the vehicles driving over the markers during normal driving conditions. The prior art pavement marker as disclosed in U.S. Pat. No. 4,147,447 is a typical example of an encapsulated reflector element within a metal road marker base. The base member includes a pair of spaced apart arcuate bottom keel portions which are mounted in grooves formed in the pavement. The upper surfaces of the keels define a pair of ramps for deflecting the snowplow blades from a plastic reflector. The reflector is mounted between the longitudinal ramps in a center portion of the casting extending between the keels. However, the reflector lenses of previously known markers have been damaged when the blade of a snowplow is angled sharply. When the blade is sharply angled, such as 45° to the axis of the road, the corner of the blade can pass between the ramps to damage the marker before the snowplow blade is deflected by the ramps. 
         [0009]    Additionally, it has been difficult to accurately position prior art castings with respect to the road surface. If the casting is placed too low, the lens of the reflector element is obscured and there is insufficient light reflected from the lens to delineate the lane. If the casting extends too far above the road surface it becomes a hazard for vehicles passing over it and is more likely to be dislodged by the blades of the snowplow. Unfortunately, where snow falls commonly occur, these embedded markers can easily become hidden when snow starts building up on the roads. In the case of traffic markers in snow fall areas, the markers must be able to withstand the impact of snow removal equipment, as well as repeated impacts from vehicle tires, and at the same time, the markers must not unduly impede snow removal or produce excessive wear or damage to snowplow blades. The marker housing itself must be able to withstand impact, and the reflector should be protected to avoid separation from the housing which has been a problem in the prior art. Further, there must also be some means by which the reflective surfaces are kept relatively clean, so that the reflective properties are preserved. In the case of a vertical reflective surface, it is particularly difficult to accomplish since road debris tends to pile up and accumulate against a vertical surface. A reflective surface with an angled surface is to some extent cleaned by rainfall as well as by the action of vehicle wheels passing over it. However, on an angled surface, some light is reflected away from the source rather than back towards it, thereby reducing the intensity of the reflected signal and thus reducing the effectiveness of the reflector. 
         [0010]    In some prior art traffic markers, cleaning is accomplished by wiping the reflective surfaces while the marker accomplishes a vertical receding movement, beneath the road surface. This retractable design allows the traffic marker to recede below the road surface as it is impacted by the vehicle wheel and rise from beneath the surface after impact. Clearly, such road markers are complicated in design and expensive to manufacture as well as economically prohibited from use by those municipalities where large quantities are required. 
         [0011]    Several approaches have been taken in the prior art to provide resistance to damage by snowplows. For example, Stolarczyk et al., U.S. Pat. No. 2,981,149 discloses a retractable highway marker wherein a casing box, is embedded in concrete and has a dome marker block projecting upward therefrom. The marker block is supported by a helical spring seated in the marker block. Reflectors are mounted to the dome marker block such that the dome marker block with reflectors recedes into the casing box as a vehicle passes thereover. 
         [0012]    To provide adequate protection for the reflector element, more recent snowplowable pavement markers have proposed the use of a single metal housing incorporating a pair of side ramps having longitudinal flanges extending outwardly from each of the ramps to position the base properly with respect to the road surface. For example Hedgewick, U.S. Pat. No. 5,975,794, proposes such design. An upper surface on each of the ramps provides a smooth continuous surface for lifting the snowplow blade up and over the reflector which is mounted between the two ramps. The flanges have a contoured periphery to prevent any sharp edges from engagement with the edge of a snowplow. This arrangement results in a marker which may be easily traversed by a tire because it has wide ramps which are shorter in length than previous castings and provides lifting surfaces for lifting the snowplow blade regardless of the angle of incidence with the base. Arcuate slots corresponding to the arcuate curvature of the base members are cut into the road and filled with adhesive. The base members are inserted into the slots and the strength of the adhesive serves to anchor the roadway marker apparatus to the road. 
         [0013]    The dependency on the strength of the adhesive leaves these traditional anchoring means exposed to failure. Any defects in terms of either the consistency of the adhesive itself or any defects in the application of the adhesive to the base member may result in an improperly anchored marker. This will lead to higher roadway maintenance costs as well as result in poor lane differentiation and thus more dangerous roads, putting public safety at risk. 
         [0014]    Obedzinski, U.S. Pat. No. 7,524,137 proposes to avoid this danger and risk by the use of separate side guards for a roadway marker. A pair of spaced apart side-guards flank opposing sides of a reflector roadway marker. The opposing side-guards are each mounted in the road with rooting pins mounted in drilled holes in the road surface. Adhesive is coated on the rooting pins and in the holes in the road to assist in securing each side-guard to the road. Although the rooting pin concept of Obedzinski solves some of the shortcomings of the Hedgewick device, the resulting reflector marker straddled by two spaced apart side-guards is not economical and therefore what is needed is a traffic marker and reflector housing that is simple in design, effective in terms of communication with the driver of a vehicle, relatively simple to install, long lasting, and cost effective. Simplicity of installation is important not only from a cost standpoint but also in view of the need to minimize disruption of traffic. 
       SUMMARY OF THE INVENTION 
       [0015]    A snowplowable roadway marker according to the present invention includes a forged elongated rail member having a top portion integrally formed with a bottom portion. The top portion includes a reflector element to communicate to a driver the lane in which a vehicle is traveling at night from a viewpoint generally ahead of that vehicle, as from another entering from a merging side road or ramp. The top portion also has two laterally spaced apart inclined upper surfaces forming ramps which are joined together at their upper ends by a bridging upper surface or rib to smoothly guide a snowplow over the reflector elements of the roadway marker. The bottom portion of the snowplowable roadway marker includes a bottom surface and located on opposing ends of the bottom surface of the elongated rail member are two integrally forged rooting pins which, after installation, the bottom surface rests on the roadway surface with the exception of the leading edges which are below the road surface while the rooting pins are recessed below the roadway surface. 
         [0016]    The inner side surfaces of the inclined ramps are tapered to define a tapered recess or pocket on each side of the bridging rib so that reflector elements secured in each pocket can be easily viewed by vehicle drivers approaching the roadway marker from both directions. The outer side surfaces of the inclined ramps also are tapered from top to bottom. The outer side surfaces may also be used to attach reflector elements which are used to assist a vehicle who is entering a highway from a merging side road or ramp. 
         [0017]    The bottom portion of the forged elongated rail member is configured with rooting pins to be placed in a pair of holes drilled into the pavement. An adhesive is placed into the pair of holes before the rooting pins of the forged elongated rail member are inserted into the holes. Undercuts in the rooting pins including a separately spring loaded clip mounted to the rooting pins act to anchor the roadway marker into the pavement as the adhesive cures so as to prevent lateral movement of the roadway marker as a result of impact conditions caused by vehicle wheels and roadway maintenance equipment such as snowplows and the like. 
         [0018]    It is therefore an important object of the invention to provide a roadway marker that is resistant to damage from snowplow blades and protects a reflector element. 
         [0019]    It is a further object of the invention to provide a roadway marker that can be secured to the roadway surface in such a manner as to provide a high degree of resistance of being removed by snowplows. 
         [0020]    It is still a further object of the invention to provide a roadway marker having high resistance to damage and displacement by snowplows, and which uses a reflector element wherein the reflector element is not directly subjected to the impact and shock loads imposed by vehicle wheels. 
         [0021]    It is yet a further object of the invention to provide a roadway marker that is of very low profile having a minimum amount of marker protruding above the surface of the pavement. 
         [0022]    It is yet a further object of the invention to provide a roadway marker that is simple in design, economical to manufacture, easy to install using conventional equipment, and durable. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a perspective view of the preferred embodiment of the invention; 
           [0024]      FIG. 2  is a top view of the roadway marker and reflector guard; 
           [0025]      FIG. 3  is a cross-sectional view taken along line  3 - 3  of  FIG. 2 ; 
           [0026]      FIG. 4  is a cross-sectional view taken along line  4 - 4  of  FIG. 3 ; and 
           [0027]      FIG. 5  is a plan view of an intersection of two streets merging together where the roadway marker can be most effective. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    With reference to the drawings,  FIGS. 1-4  illustrates a roadway marker and reflector guard  10  according to a preferred embodiment of the invention. The roadway marker, designated by reference character  10 , in use, is intended to be embedded in the pavement  15  of a roadway so as to project above the roadway surface  18  and be visible from oncoming vehicles traveling in either direction along the roadway surfaces  18 , while being protected from snowplow blades (not shown) inclined at an acute angle to the direction of travel along the pavement  15 . The roadway marker  10  includes a longitudinally elongated unitary body that supports thereon retro-reflector elements which will be described hereinafter. 
         [0029]    The roadway marker  10  is formed from a relatively high-strength material. The roadway marker  10  is preferably forged as an integral unit having a body or base  20  having a lower portion  22  which is mounted in the pavement  15  and an upper portion  24  which includes a pair of elongated, laterally spaced apart rail or ramp members  26  for protecting the reflector elements from a blade of a snowplow. The ramp members  26  are designed so that their leading edges  28  are intended to be placed below the pavement level  15 . The ramp members  26  have an incline  30  towards the longitudinal central portion of the roadway marker  10  and terminate into a bridging upper surface or rib  32  which is substantially parallel to the roadway surface  18 . The bridging upper surface  32  is at a level above the uncut pavement level  15 . The incline  30  of the ramp members  26  raises an oncoming snowplow blade up and over the forged roadway marker  10 . Each pair of ramp members  26  straddling the bridging upper surface  32  also converge  34  towards the longitudinal central portion of the roadway marker  10 . 
         [0030]    Each pair of inclined ramps members  26  is defined by tapered outer sidewalls  36 . Along the outer periphery of the roadway marker  10 , a tapered outer sidewall  36  extends from the base  20  upwards to an outer top edge  38  of each ramp member  26 . The inner top edges  40  are also the terminus for a tapered inner sidewall  42  which extends from the top of the ramp member  26  to a recessed surface  44  of a recessed area  46 . The recessed area  46  receives a reflector element as will hereinafter be discussed. 
         [0031]    A particular problem with pavement markers, especially in snowbelt country, is that of maintaining the pavement marker  10  in place on the roadway surface  18  under the frequent shock loads imposed by the wheels of vehicles passing over the pavement markers  10  as well as the loads delivered by snowplow blades during maintenance of the roadways in winter months. These impact loads are generally delivered near the very ends of the lower portion  22  of the base  20  of the roadway marker  10 . To reduce the impact force, the leading edge of the roadway marker  10  is placed about ¼ inch below the pavement level so that when a snowplow blade impacts the roadway marker  10 , the impact is made on the incline  30  of the ramp members  26 . To resist the impact force, the lower portion  22  of the base  20  on each end includes a rooting pin  48 ,  50 . In this preferred embodiment, the rooting pins  48 ,  50  are in the form of elongated cylindrical elements depending downwardly near the leading edge of the roadway marker  10  as part of the base lower portion  22 . Other configurations or shapes are within the contemplation of this invention. The rooting pins  48 ,  50  create two anchoring points for the roadway marker  10 . This doubles the anchoring force as compared to a single downwardly depending arcuate rib as exemplified in the prior art and allows for a more even distribution of forces on the pavement  15 . 
         [0032]    As best shown in  FIG. 3 , each of the rooting pins  48 ,  50  are substantially perpendicular to the roadway surface  18  when the roadway marker  10  is installed in the pavement  15 . Each of the rooting pins  48 ,  50  also has a rounded end  52 ,  54  spaced from the base  20  of the roadway marker  10 . In the preferred embodiment of the invention, each of the rooting pins  48 ,  50  are aligned with the ends  31  of the inclined surface  30  of the respective ramp members  26  so as to provide a generous contour  55  at the intersection of the bottom or end  31  of the inclined ramp  30  and the outer diameter surface of each rooting pin  48 ,  50 . This generous contour  55  provides a smooth transition between the ends of the tapered inner sidewall  42  of the recessed area  46  between the ramp members  26  and the outer diameter surface of each rooting pin  48 ,  50 . Since each peripheral end of the roadway marker  10  is intended to be located approximately ¼ inch below grade with the center of the base  21  located at road level, it is this contour  55  that will first initiate an impact with the vehicle wheel or snowplow blade. 
         [0033]    In order to obtain maximum retention capability by the adhesive used to permanently hold the rooting pins  48 ,  50  in a hole  56  drilled in the pavement, each rooting pin  48 ,  50  is provided with a plurality of laterally spaced recesses or anchor recesses, as exemplified by recess  57  as best shown in  FIG. 3 . Further, to maintain the rooting pins  48 ,  50  in position in the drilled hole  56  until the adhesive dries, a pre-loaded retainer clip  58  is clipped in at least one of the anchor recesses in the outside diameter of each rooting pin  48 ,  50  prior to inserting the rooting pin  48 ,  50  into each respective hole  56  which has been filled by an adhesive. The retainer clip  58  has barbs  60  on its outer diameter which create frictional interference with the walls of the hole  56  so that once installed in place, the barbs  60 , because of the frictional interference with the walls of the drilled hole  56 , will not allow the rooting pins  48 ,  50  to attempt to work its way out of the hole  56  before the adhesive cures. Back pressure is created by the action of inserting each rooting pin  48 ,  50  into each hole  56  filled with adhesive and the displacement of the adhesive causes a back pressure. To assist in reducing the effect of this adhesive displacement pressure, an axially oriented groove  62  is forged in the outside diameter of the rooting pins  48 ,  50 , from the bottom end to the top end, to assist relieving the backpressure created by displacement of the adhesive as the rooting pins  48 ,  50  are inserted into each hole  56  upon installation in the pavement  15 . The adhesive used in the preferred embodiment is an epoxy adhesive although it is well understood by those skilled in the art that a wide variety of adhesives may be used. 
         [0034]    As disclosed hereinabove, the highest point of stress occurs near the ends of the roadway marker  10  when the vehicle or snowplow first comes into contact with the roadway marker  10  in the vicinity of the contour  55 . To increase the resistance to stresses, the underside of the base  20 , along the lower portion  22  is reinforced with additional material in the form of a large inside radius  64  between the underside of each pair of ramps and the interface with the rooting pins  48 ,  50 . A constant cross-section is maintained for the complete length of each inclined ramp. This constant cross-section is then forged with the inner radius  64  as well as contour  55  providing a smooth transition from the inclined ramps to the outside diameter of the rooting pins  48 ,  50  on both the top and bottom of the lower portion  22  of the base member  20 . 
         [0035]    As disclosed above, the recessed area  46  between each pair of inclined ramps  26  is for the purpose of housing reflective elements to be mounted on the tapered inner sidewall  42  as well as the recessed surface  44  of the recessed areas  46  between the inclined ramps  26 . It is also foreseen that reflector elements will be mounted on the tapered outer sidewall  36  along the outer periphery of the roadway marker  10  such that it can be easily identified to a driver that enters the highway from a side-street or entrance ramp. The tapered outer sidewalls  36  may be forged with a small depression (not shown) in order to accommodate the reflector element. For example, if the reflective element is in the form of a reflective tape, the tape may be fabricated to fit into the small recess and then sealed in position by a clear polycarbonate lens and ultrasonically welded thereto. If the reflective element is in the form of a reflective powder-coat that is sprayed onto the surface and cured in place, there is no need for a recessed surface in the outer tapered sidewall  36 . In the case of a plastic reflector, it may be desirable to provide a recess into which the plastic reflector is adhesively sealed. Depending on the application, it is understood that the reflective element used is specifically designed to reflect light in specific angular ranges, in each case to suit the specific application. 
         [0036]    In the preferred embodiment described reflectors are disclosed to be installed in both the recessed area  46  as well as the tapered outer sidewall  36  of the ramp members  26 . It is foreseeable that reflector elements are used only in both recessed areas  46  without the use thereof on the tapered outer sidewalls  36 . Such roadway markers could find application in situation where motorists only need to see a road marker from one direction, i.e., on a one-way road. 
         [0037]    The roadway marker  10  is installed by drilling a pair of holes  56  to an appropriate depth into the roadway at a predetermined spaced interval. The holes  56  are not perpendicular to the roadway but at a slight acute angle to the roadway as is illustrated in  FIG. 3  in hyphenated lines. A relief  65  in the form of a radius cut is then cut into the pavement  15  to create a clearance in order to accommodate the large inside radius  64  in the lower portion  22  of the base  20  between the pair of rooting pins  48 ,  50 . A retainer clip  58  is then placed on each of the rooting pins  48 ,  50 . Thereafter, the adhesive is placed in both holes. Prior to insertion of the rooting pins  48 ,  50  into the holes, the bottom  20  of the rail member is coated with the adhesive to assist in securing the base  20  of the marker to the road. Both rooting pins  48 ,  50  are then inserted into the respective holes  56 . The barbs  60  on the retainer clip  58  interact with the walls of the holes  56  to create a frictional interference so that when the base  20  of the roadway marker  10  locates on the roadway surface  18  the roadway marker  10  will remain in place, and not be forced upwards out of the holes  56  by the reaction to the displacement of the adhesive within the hole, until the adhesive completely cures and vehicle traffic is permitted to traverse the roadway marker. 
         [0038]    The purpose of drilling the holes  56  at a slight acute angle is to help retain the rooting pins  48 ,  50  in the holes  56 . Any upward force created by a vehicle or snowplow passing over the roadway marker will be resisted by the adhesive trying to retract out of the hole  56 . The small acute angle creates an interference with any force attempting to pull the rooting pin  48 ,  50  horizontally out of the holes  56 . The interference created by the adhesive with the sidewall of the hole  56  will make it more difficult to remove the rooting pin  48 ,  50  with a horizontally upward force. 
         [0039]    In operation, the roadway marker of this invention is implanted at spaced intervals along the edges of lanes of a multi-lane roadway to provide a system to delineate the lane in which a vehicle is travelling at night from positions generally ahead of the vehicle. The markers may be implanted and attached, as by an adhesive such as epoxy composition, to mark the outer edges and common middle edge of a double lane roadway, for example, as illustrated in  FIG. 5 . In this system inner lane  66  and outer lane  68  are parallel adjacent lanes having roadway markers,  10  for example, as described and illustrated in  FIGS. 1-4 , implanted at intervals as shown. The headlights of a vehicle  70 , travelling in outer lane  68  at night, will illuminate markers  10  ahead of it, specifically markers  10   a , and the light falling on the recessed surface  44  and tapered outer sidewall  36  of these markers will be reflected backwards as well as forwards and will be visible by the driver of the vehicle  70 . A merging ramp or road  72  is shown on which another vehicle  74  is just about to enter or merge into roadway lane  68 . The driver of the vehicle  74  can look back along roadway lane  68 , either directly or through his rear view mirror, and seeing the brightly lit roadway markers  10  of the tapered outer sidewall  36  can readily determine that the vehicle  70  is in the outer lane  68  and not in inner lane  66 . Warned of the danger he can slow down or stop until vehicle has passed and it is safe to enter lane  68 . The headlights of vehicle  74  will to some extent illuminate markers  10   b  as he enters lane  68 , providing indication of his entering lane location to drivers ahead of him. 
         [0040]    In a comprehensive installation, markers  10  may be placed along all edges of the lanes of a multilane roadway as illustrated in  FIG. 5 . This provides lane indication from forward positions of vehicles in all lanes, and may be useful for a driver wishing to switch into another lane, for example, facing a situation somewhat similar to that facing a driver merging from an on-ramp. In a more limited embodiment, markers  10  may be placed at edges of the outside lane and at areas near or approaching on-ramp or merging side road junctions to provide positive lane delineation at the most dangerous locations. 
         [0041]    While the present invention has been described in terms of a preferred embodiment, it is apparent that other forms can be adopted by one skilled in the art. For example, the teachings of the present invention encompass any reasonable substitutions or equivalents of claim limitations. Those skilled in the art will appreciate that other applications are possible with this invention. Accordingly, the present invention is not limited to the preferred embodiment disclosed. Accordingly, the scope of the present invention is to be limited only by the following claims.