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FIELD OF THE INVENTION  
       [0001]     The present invention relates to an apparatus and method for removing road markings such as lane lines, stripes, arrows and the like from roads.  
       BACKGROUND OF THE INVENTION  
       [0002]     Road lane markings, such as lane lines, stripes, arrows and the like are commonly applied to road lanes for designating vehicular traffic flow.  
         [0003]     Large efforts have been expended to improve the durability of these road markings in the face of intensive wear caused by vehicle tires and deterioration caused by the sun and weather. Hence, there have been a variety of marking substances (special paints, heated thermosetting or reactive thermoplastics, epoxy and other materials) developed and introduced.  
         [0004]     Techniques have also been developed to increase the thickness of the applied paint layer composing the markings, so that it will be felt by drivers when passed over and to produce reflecting effects to increase the ease and safety of night-time driving.  
         [0005]     Occasionally there exists the need to erase existing road markings. This may occur when the road undergoes maintenance operations, changes such as the addition of a lane or lanes, temporary deviations or detours, or other circumstances requiring the erasure of road markings.  
         [0006]     A typical method to eliminate the markings is simply to cover them with a layer of pitch. However, this cover material can prove to be reflective when illuminated by vehicle headlights, which of course is confusing and uncomfortable for the driver and may cause a traffic safety problem. If the markings are chipped off (e.g. with chisels or by sand blasting), the result will be the formation of cavities or depressions that may endanger driving and damage vehicles.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention relates to an apparatus and method for removing road markings such as lane lines, stripes, arrows and the like (hereinafter in the specification and claims, “road markings”), from roads the apparatus comprising a chassis adapted to travel over the road lane; a heating source mounted to the chassis for directly or indirectly applying heat to the road marking; and a positively driven rotatable brush mounted to the chassis. The brush has bristles contactable with the road marking and adapted for removing the road marking, when heated, from the road.  
         [0008]     The method for removing road markings from roads comprises: 
        providing an apparatus comprising a chassis with a heating source and a rotatable brush mounted thereto, the brush having bristles;     bringing the apparatus to the road lane;     causing the chassis to travel over the road lane;     applying heat directly or indirectly to the road marking; and     causing the bristles of the brush to rotate and contact the road marking thereby removing the marking.        
 
         [0014]     The chassis is typically adapted for mounting or attaching to the front of a truck or other suitable vehicle. Mounting to the front of the truck aids visibility of the markings to be removed, however, the apparatus can be designed for rear mounting or even mounting such that at least the bulk of the apparatus is disposed to the side of the truck.  
         [0015]     It is preferable that the apparatus comprises a means to displace the chassis, or at least, the brush, in a direction transverse to the truck, to facilitate alignment of the brush with the markings. Alternatively, the apparatus may be designed in a simpler manner wherein it does not include such means to displace the brush or chassis and the appropriate alignment of the brush with the markings is obtained by appropriately positioning the truck controls. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     These and additional constructional features and advantages of the invention will become more clearly understood in the light of the ensuing descriptions of embodiments thereof, given by way of example only with reference to the accompanying drawings, wherein:  
         [0017]      FIG. 1  is a schematic side view of an apparatus and associated vehicle for removing road markings according to the present invention;  
         [0018]      FIG. 2  is a top view of the apparatus in  FIG. 1 ;  
         [0019]      FIG. 3  is a bottom view of the apparatus of  FIG. 1 , on an enlarged scale;  
         [0020]      FIG. 4  is a view in the direction of arrow IV in  FIG. 2 , on an enlarged scale;  
         [0021]      FIG. 5  is a schematic side view of another embodiment of the apparatus according to the present invention; and  
         [0022]      FIG. 6  is a view in the direction of arrow VI in  FIG. 5 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]     Schematically shown in  FIGS. 1 and 2  is a vehicle  10 , generally of any conventional type, e.g. a small truck, the vehicle adapted however to allow the attachment (e.g. mounting, connecting) thereto of an apparatus  12  designed for removing or erasing road markings M from a road R. The apparatus  12  is shown mounted to the front of the vehicle  10  by a pair of brackets  14  and  16 .  
         [0024]     The apparatus  12 , as a whole, is mounted to the brackets  14  and  16  by both a cross shaft  18  and a screw-threaded spindle  20 , best seen in  FIG. 4 , extending parallel to each other. The apparatus  12  is thus suspended above the road R, in cantilever fashion, carried by horizontal chassis side rails  22 ,  24  rigidly connected to vertical rails  26  and  28  ( FIG. 4 ). Rails  26  and  28  are coupled to the shaft  18  by slide bearings  30  and  32  and to the spindle  20  by nuts  34  and  36 , respectively.  
         [0025]     Alternatively, the apparatus  12  could be adapted to be at least partially supported above the road R by means other than, or in coordination with, the cantilever type arrangement detailed herein above. One such means is the use of any number of wheels (not shown) to allow the apparatus  12  to ride over the road R. By one aspect of this alternative, the weight of the apparatus  12  could be supported by these wheels in conjunction with the brackets  14  and  16  to support the apparatus. By another aspect, the weight of the apparatus  12  could be completely supported by wheels.  
         [0026]     If the apparatus  12  were completely supported by wheels, the attaching arrangement need merely be a connecting mechanism to allow pushing (or pulling) thereof, and need not be a load bearing mechanism such as mounting.  
         [0027]     With reference to  FIGS. 1 and 3 , the apparatus  12  is further provided with a heating source  50  such as a multi-flame burner unit having torches  51 . The heating source  50  is suspended from above (although alternatively, it may be supported from below), and adjustably movable by an assembly comprising a pneumatic cylinder  52  and a piston  54  mounted to a top rail  56 , guided by rollers  58 ,  60  along vertical rails  62 ,  64  respectively. A chimney fitting tube  66  extends upward into a chimney  68  to enable up and down movement of the heating source  50 .  
         [0028]     Alternatively the heating source could be, for example, an electric forced air heater (not shown) powerable by the vehicle&#39;s battery or another source of electricity.  
         [0029]     As seen best in  FIG. 4 , the apparatus  12  can be transversely moved from side to side by rotation of the spindle  20  while maintaining an essentially constant height above the road R. The spindle  20  may be rotated in either or both directions by known means such as an electric drive motor  38  coupled thereto by sprocket wheels  40  and  42  via a sprocket chain  44 .  
         [0030]     A supply line  70 , at least a portion of which is helically configured, is provided for flowing combustible gas or liquid (e.g. butane, propane, natural gas, kerosene etc.) from gas containers  72  carried by the vehicle  10  ( FIG. 1 ). The helical configuration allows for movement of the heating source  50  and an analogous configuration (not seen) allows the transverse movement of the apparatus  12 .  
         [0031]     The apparatus  12  further comprises a high-speed rotatable brush  80 , mounted on an axle  82  which is driven by a motor  84  via a belt  86 —or other known means. The arrangement can be designed such that the brush  80 , comprising bristles  88 , can be rotated in either direction, however it is typically more effective for the brush to rotate in the direction opposite that of the progress of the vehicle  10 .  
         [0032]     The pressure of the brush  80  on the road markings M could be defined simply by the stiffness of the bristles  88  of the brush  80 . To this end, the brush  80  could comprise bristles  88  of any combination of different length, thickness, stiffness and material (as long as the bristles reasonable withstand the heat and wear) to thereby optimize the pressure on the markings M and their removal.  
         [0033]     However, to control and even out the pressure of the brush  80  on the road markings M, other means such as a spring (not shown) biased to press downward with a desired pressure or a weight (not shown) may be associated with the brush.  
         [0034]     It should be understood that the bristles  88  of the brush  80  are configured in a pattern such that they contact the road markings M throughout the area of the markings, and to this end, groups of bristles may be shifted, offset, irregularly arranged, etc. For sake of clarity, this is not depicted in the figures.  
         [0035]     The operation of the apparatus  12  for removing road markings M is as follows:  
         [0036]     First, the truck  10  is driven to the location where erasure of road markings M is desired and it is positioned in alignment therewith. Due to the transverse displacement arrangement as explained above (using the spindle  20 ), it is not mandatory that the truck  10  itself be centered on the markings M, rather only the apparatus  12 —and in actuality the brush  80 —need be aligned with the road markings M. This feature allows removal/erasure of markings M adjacent the margins or shoulders of road lanes without driving with half the vehicle  10  off the road; and allows the removal of centrally located road markings without need to drive the vehicle in the center of the road R which would potentially block traffic.  
         [0037]     Then, while the torches  51  are burning and the brush  80  is rotating, the vehicle  10  is slowly driven over the road markings M thereby removing them.  
         [0038]     The heating of the road markings M by the torches  51  may be direct with the distance of the torches from the road markings being adjustable, as described above. The distance of the torches  51  from the road markings M can be used to adjust and optimize the heat applied to the markings.  
         [0039]     However, the heating of the road markings M may be indirect, for example by means depicted in  FIGS. 5 and 6  (where reference numerals similar to those of  FIGS. 1-4  have been used but with the numeral “1” preceding).  
         [0040]     As seen in  FIGS. 5 and 6 , the location and mode of operation of the brush  180  remains unchanged. However, the heating source  150  with torches  151  now corresponds with the brush  180  such that the heat is applied to the bristles  188  of the brush  180 . The torches  151  are preferably at an angle to the bristles  188 , as seen in  FIG. 5 . This has the effect of improving the heat transfer to the bristles  188  as well as avoiding excessive heating of the hub of the brush  180 .  
         [0041]     Hence, now it is the heated bristles  188  that heat the road markings M and together with rotation of the brush  180  remove the markings. Thus, the only portion of the road R that is significantly heated is that portion contacted by the brush  180 —presumably just the road markings M.  
         [0042]     The heating source  150  is again displaceable by an arrangement comprising, for example, a pneumatic cylinder  152 , a piston  154 , and supporting rollers  158  and  160  for adjusting the amount of heat applied to the brush  180 . Examples of alternate arrangements for displacing the heating source  50 ,  150  include a threaded spindle (like spindle  20 ), a gear mechanism, extending-retracting scissor-like rods, a lever system, and the like.  
         [0043]     One example of a modification of the above embodiments includes the use of extra brushes (not shown)—potentially each brush having its own heating source. These brushes may spin in opposite directions to thereby improve removal of the markings removal on uneven roads. In a further option, the brush  80 ,  180  or brushes just referred to may be rotatable at different rpm, and have bristles  88 ,  188  of different characteristics, e.g. lengths, thicknesses, materials, etc.  
         [0044]     Another example of a modification of the above embodiments includes the use of extra heating sources (not shown); e.g. an arrangement wherein both the road R and brush  80 ,  180 —or brushes—are heated.  
         [0045]     Yet another example of a modification of the above embodiments includes the use of an additional heating source, or “branch” of the existing heating source (not shown) disposed at the back side of the brush  80 ,  180 . It may happen that some amount of material composing the road markings M may stick to the brush bristles  88 . This added heating source may improve removal of road markings material from the brush  80 ,  180 , if any sticks thereto. In the embodiment where the brush  180  is heated by the heating source  150  ( FIGS. 5 and 6 ), that heating source may be sufficient to maintain the cleanliness of the brush bristles  188 .  
         [0046]     Furthermore, as the road markings M may be composed of various materials and thicknesses, it may be desirable to have available brushes  80 ,  180  of different characteristics. This can be accomplished, for example, by having more than one brush type installed in the apparatus  12  adaptable to position the appropriate brush adjacent the road markings M or adapting the brushes to allow quick change-out thereof.  
         [0047]     Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations and modifications can be effectuated without departing from the true spirit and scope of the invention as defined in and by the appended claims.

Summary:
An apparatus for erasing a road marking on a road lane comprising a chassis adapted to travel over the road lane; a heating source mounted to the chassis for directly or indirectly applying heat to the road marking; and a positively driven rotatable brush mounted to the chassis. The brush has bristles contactable with the road marking and adapted for removing it, when heated, from the road. Indirect heating of the road marking can be accomplished by first heating the bristles of the brush.