Patent Publication Number: US-2018030678-A1

Title: Striping apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Patent Application No. 62/369,429, filed Aug. 1, 2016, titled “Ribbon Gun,” the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments herein relate to the application of marking indicia to roadways and runways. 
     BACKGROUND 
     Highway and road markings have been used for many years to guide drivers as they maneuver vehicles down the road. Examples are interrupted yellow lines between different lanes of travel, passing and no-passing zones, white side lines, pedestrian lanes, bicycle lanes, turn and no-turn lanes, and other marking indicia. Such striping is also used on airport runways to identify areas where airplanes should and should not be maneuvering, lanes to and from runways, to and from gates, and for similar uses. All of these uses are within the definition of “road marking,” “road surface” or “roadway” as used herein. Most of these markings use an aqueous traffic paint, which typically includes polymer particles containing soft and hard polymers, along with suitable solvent compositions. Various other thermoplastic materials are also used. One material that has recently been introduced is methyl methacrylate (“MMA”). 
     Systems for applying marking vary greatly. Many involve spray painting lines and other indicia. Such systems have worked reasonable well since they do not have to actually contact the road surface, which is not only rough and irregular but is often covered with debris. However, spray paint road marking systems sometimes have difficulty defining edges and starting and stopping points when intermittent marking is desired. In addition to issues with definition, such striping is often not thick enough to last through years of traffic, snow plowing and weather. In order to be sprayed, the paint cannot be very viscous, and this further reduces the thickness of the coatings or striping being applied. 
     Various thermoplastic materials have been applied to the road surface as a thick ribbon, which overcomes some of the drawbacks expressed above. However, because the material is thermoplastic, the material has to be kept hot until it hits the road surface. This requires that some sort of jacket surround the application member, which creates practical difficulties. A knife that is designed to open and close the application member and controls the flow of the thermoplastic material out of the member and onto the road surface. 
     MMA is an extremely durable plural component material that can be used for applying marking indicia to road surfaces. MMA is normally applied by one of two methods. A heavy “shoe” apparatus has been used, which is dragged over the road surface, with a knife being used to close off the shoe gate that distributes the MMA. MMA can also be applied using a spray process but materials may need to be removed from the MMA to make it less viscous so it can be sprayed through a spray head. 
     While these two systems of applying MMA to a road surface have been generally satisfactory, there are many drawbacks. Using the shoe system that contacts the road surface requires a heavy duty shoe that often gets fouled with road debris or the MMA itself, which tends to stick to anything in which it comes into contact. This requires the application process to be stopped while the shoe is cleaned. Also, because the shoe rides directly on the road surface, irregularities and unevenness in the surface results in variations in the indicia being applied and problematic wear to the shoe itself. 
     As noted above, spraying through a spray head requires the MMA to be thinned to reduce viscosity. This reduces the thickness and therefore the durability of the indicia. It also can result in the definition of the lines and other indicia being reduced. 
     The disclosed embodiments provide an apparatus is provided for applying fluid material to a road or runway surface. The apparatus includes a material distribution bar to be extended laterally and parallel but spaced from the surface, the bar having closed ends and defining a laterally-extending fluid distribution slot through which material is to be pumped; a system for providing material under pressure in a flow path; and a valve disposed between the material distribution bar and the system for providing material under pressure, to selectively open and close to control the flow of material from the system to the material distribution bar and the fluid distribution slot. 
     The apparatus may also include a valve control mechanism for selectively opening and closing the valve, the mechanism comprising a fluid-operated piston and cylinder arrangement (it is typically pneumatic) in which fluid under pressure is provided to displace to both open and close the valve. 
     The material distribution bar may be in the form of a cylindrical bar having removable caps on each end, with a conduit extending from the system for providing material under pressure in a flow path. 
     An apparatus for spraying fluid material onto a road or runway surface may also be provided including a spray valve having an air inlet defining an air fluid path and a material inlet defining a material fluid path, the two paths merging immediately prior to an outlet orifice, a system for providing material under pressure in a flow path, a valve disposed between the spray valve and the system for providing material under pressure to selectively open and close to control the flow of material from the system to the spray valve, and a valve control for selectively opening and closing the valve, the valve control comprising a piston/cylinder arrangement with fluid controls to positively drive the piston to both open and close the valve, and including a rod extending from the piston/cylinder arrangement to a control ball, which is selectively moved into and out of engagement with a seat to close and open the valve, respectively. The fluid may be air (pneumatic) or oil (hydraulic) although pneumatic control systems are preferred. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. 
         FIG. 1  is a perspective view of a first embodiment of the present invention, showing the application gun and a material distribution bar; 
         FIG. 2  is a side elevation view of the embodiment of  FIG. 1 ; 
         FIG. 3  is a front elevation view of the embodiment of  FIG. 1 ; 
         FIG. 4A  is a side elevation sectional view of the embodiment of  FIG. 1 , with the valve in an open position, but not showing the distribution bar for simplification; 
         FIG. 4B  is a side elevation sectional view of the embodiment of  FIG. 1 , with the valve in a closed position, but not showing the distribution bar for simplification; 
         FIG. 5  is a perspective view of a second embodiment of the present, showing the application gun and a spray nozzle; 
         FIG. 6  is a side elevation view of the embodiment of  FIG. 5 ; 
         FIG. 7  is a front elevation view of the embodiment of  FIG. 5 ; 
         FIG. 8  is a side elevation sectional view of the spray valve of the embodiment of  FIG. 5 ; 
         FIG. 9  is a perspective view of the embodiment of the material distribution bar depicted in  FIG. 1 ; 
         FIG. 10  is a perspective view of another embodiment of a material distribution bar; and 
         FIG. 11  is a perspective view of yet another embodiment of a material distribution bar. 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents. 
     Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order dependent. 
     The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments. 
     The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other. 
     For the purposes of the description, a phrase in the form “A/B” or in the form “A and/or B” means (A), (B), or (A and B). For the purposes of the description, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). For the purposes of the description, a phrase in the form “(A)B” means (B) or (AB) that is, A is an optional element. 
     The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments, are synonymous. 
     The depicted embodiments utilize a so-called “ribbon” application process that lays down a ribbon of striping or other indicia that can be precisely located, with clean definition to the edges, and can provide a wide variety of thicknesses, depending up the precise material being applied, the surface to which it is being applied, the durability that is required due to traffic and weather. Moreover, the depicted embodiment facilitates these advantages while being suspended over the road surface, thus eliminating many of the drawbacks with the shoe system that rides directly on the road surface; that is, the equipment does not get fouled due to road debris, can be lightweight because it will not encounter the wear associated with direct contact, and is not affected by irregularities in the road surface that can cause the shoe to be deflected, worn or cause the indicia to be applied in an unintended pattern. 
     The Embodiment of FIGS.  1 - 4   
     One form the apparatus for applying the marking indicia may take is that depicted in  FIGS. 1-4 . The striping apparatus is depicted generally at  10 . It typically includes two portions —an application gun  12  designed to provide material for distribution under pressure, and a material distribution bar  14 , which applies the material onto the roadway. The term “material” as used herein can be any type of fluid material used to apply striping or other marking indicia to roadways or runways. It might be any type of polymer or other thermoplastic material. As noted above, MMA appears to be particularly well suited for this purpose. 
     While it should be understood that application gun  12  and distribution bar  14  are normally used together, some applications may permit material feed systems other than application gun to supply material to the distribution bar. The term “ribbon” is used herein to describe the material being distributed through distribution bar  14 . The term is particularly appropriate when used with the depicted apparatus  10  because it can be laid down in an extremely viscous and thick layer of indicia that readily applies itself to even a somewhat irregular road surface but also will be extremely durable due to the thickness of the ribbon. 
     Application gun  12  is designed to provide MMA or other striping material under pressure to distribution bar  14 . Actually, striping material is typically provided to the application gun at the desired pressure, with the striping material already mixed and ready to be applied to the road surface. The equipment for doing that is conventional in design and therefore has not been depicted and will not be described. 
     Application gun  12  may include an intake nipple  16 , a valve drive cylinder  18 , a valve  20  (See  FIGS. 4A  and B), and a gun discharge end  22 . Intake nipple  16  is connected to a system for mixing and supplying MMA or other material, and provides that material under pressure to valve  20 . Since the material is being directed downward toward gun discharge end  22 , intake nipple  16  may be disposed at an oblique angle with respect to valve  20 . It may be threaded into place or mounted in some other removable fashion so it may be removed from valve  20  for cleaning or replacement. A block  23  may be provided on the side of application gun  12  to mount the gun to adjacent structure on a vehicle carriage (not shown). 
     Valve  20  may include a valve seat  24  which is designed to receive a ball valve  26  as shown best in  FIG. 4B  in its seated position. Ball valve  26  is typically mounted to a valve control rod  28 , which extends between the ball valve and a valve control mechanism, which may include a cylinder  32  (See  FIGS. 4A  and B). As the name suggests, the valve control mechanism controls the position of valve  26 , causing it to open upwardly to the position depicted in  FIG. 4A  when MMA or other material is intended to be pumped from intake nipple  16  to discharge end  22 , and close downwardly against valve seat  24  to the position in  FIG. 4B  when the flow of material is to be stopped. 
     Cylinder  32  may have a reciprocable piston  34  therein (See  FIGS. 4A  and B), the position of which is controlled by two pneumatic lines with connections  36  and  38 , shown in  FIGS. 1-3 . It can be seen that piston  34  acts as a double-acting piston with air being pumped into or drawn from the top or bottom of cylinder  32 , depending upon the desired position of ball valve  26 . This positive force on the top or bottom of piston  34  ensures that ball valve  26  will be positively driven into the desired position even if viscous MMA or other material is disposed in valve  26 . As shown best in  FIGS. 4A  and  4 B, appropriate air seals  40  and  42  are included adjacent piston  34  and valve control rod  28 , respectively, to minimize air leakage during the operation of piston. 
     One of the advantages of apparatus  10  is that striping material does not need to be applied using compressed air. This may eliminate the need for a large compressor being mounted to the application vehicle. Given that piston  34  can be operated using a small amount of air, a small compressed air bottle may be used on the vehicle instead of having a large air compressor. 
     A lock nut  44  may be included to fix the position of valve control rod  28  with respect to a piston rod  46 , and evenly spaced head bolts  48  may be provided to maintain the integrity of cylinder  32  in conventional fashion. 
     Where valve control rod  28  enters valve  20 , a threaded seal bushing  50  secures a seal  52  in place against a threaded valve bushing  54  to minimize leakage of MMA or other material from the valve. 
     As shown in  FIGS. 1-3 and 9 , material distribution bar  14  is mounted via a bar nipple  54  to gun discharge end  22  to receive MMA or other material from application gun  12  and distribute it in a ribbon onto the roadway or other surface. A fluid distribution slot  56  extending much of the length of distribution bar  14  is provided at the bottom of the bar to distribute material in the desired pattern. The slot is designed to extend laterally with respect to the roadway or other surface, or perhaps better expressed, laterally to the direction of travel of the vehicle with which apparatus  10  is moving across the surface. In normal usage, it will be spaced from the surface by a distance that depends on the material being applied, the form the indicia are to take, the undulations and other variations in the surface, and other factors. This spacing might be in the range of one to several inches. 
     A cap  58  is provided at each end of distribution bar  14 . Caps  58  may be threaded so they can be removed for periodic cleaning. In certain applications it may be desirable to pack grease into the ends of bar  14  prior to mounting a pair of grease caps  58  to minimize the likelihood of material hardening onto them. Slot  56  may be a wide variety of dimensions, depending on the application, the conditions, and the material being distributed but it has been found that, with a bar inner diameter of 1 inch, a slot that is ⅛ or ¼ inch wide and 4 inches long is suitable, although the slot  56  may be 12 inches long or longer, depending on the width of the desired stripe. 
     There are many advantages with the use of the apparatus  10 , some or all of which may be achieved, depending on the application conditions and the components actually selected. First and foremost, there is nothing in the system that needs to touch the surface being striped. This facilitates a smooth, consistent ribbon of material to be applied to the road or other surface. Deviations, contours or rough surfaces do not affect the quality of the stripe or other marking indicia. As mentioned above, apparatus  10  does not require air to move striping material through the apparatus. With no need for air, equipment costs are less, as vehicle-mounted compressors are no longer over-worked, saving maintenance and fuel costs. Unlike a spray application, there is little problem with definition at the edges of the indicia because air is not used to drive the material through. 
     Because distribution bar  14  does not contact the surface to which the material is being applied, apparatus  10  will rarely need to be stopped for cleaning. In the event distribution bar  14  does become fouled, it can be quickly and easily replaced, or it can be easily cleaned by removing caps  58 . The cleaning of shoes larger amounts of solvent, which can be a hazardous material, requiring troublesome and sometimes expensive disposal. 
     The Embodiment of FIGS.  5 - 8   
     The embodiment of  FIGS. 5-8  may be the same as that of  FIGS. 1-4  other than the replacement of the distribution bar with a spray nozzle  158 . While there are many advantages in using apparatus  10  with distribution bar  14 , in some applications it may be desirable to use an application gun like that shown at  10  in combination with a spray head instead of a distribution bar. In this second embodiment, the principal parts of the application gun have been identified with numerals corresponding to the embodiment of  FIGS. 1-4 , except that they are in the  100  series. The apparatus has thus been identified at  110 , the application gun at  112 , the intake nipple at  116 , the valve drive cylinder at  118 , the valve at  120 , and the gun discharge end at  122 . 
     As best shown in  FIG. 8 , spray nozzle  158  includes a material intake end  160 , an air intake  162  and a spray outlet  164 . The material is pumped into material intake end  160  and passes through a centrally-disposed material channel  166  toward spray outlet  164 . Immediately prior to reaching the spray outlet, the material is subjected to pressurized air that is pumped through air intake  162  to a series of evenly-spaced air channels  168  that mix with the material and spray it out spray outlet  164 . 
     To facilitate cleaning of spray nozzle  158 , the spray nozzle may be formed of several different pieces that are removably fastened to each other, such as by threads. A spray tip  170  including a spray orifice  172  may be mounted at the very end. Replacement of spray tip  170  with tips having larger or smaller orifices is thus possible, which may be an advantage to facilitate apparatus  110  being used for different materials, different indicia requirements, and different operating conditions. 
     In the depicted embodiment, spray tip  170  is not threaded to the rest of spray nozzle  158  but instead is secured in place by a collar  174  that is threaded to a spray nozzle adaptor  176 , which is in turn threaded to a pipe coupler  178 . Pipe couple  178  may be detachably mounted, such as by threading, to other members, the top member of which is detachably mounted, such as by threading, to gun discharge end  122 . 
     The Embodiments of FIGS.  10  and  11   
     The embodiments of  FIGS. 10 and 11  are simply different embodiments of the material distribution bar  14 , which include two or three bar nipples, here  254  and  354 , which may be removably mounted, such as by threading. These embodiments of the distribution bar, identified at  214  and  314 , respectively, may in all other respects be the same as the embodiment of  FIGS. 1-4  but may be desirable in the event wider material ribbons need to be spread onto the roadway or other surface. Each of these embodiments include a slot  256  or  356  through which material in the form of a ribbon is designed to pass. While the precise dimensions of slots  256  and  356  may vary, again, depending on the application, the conditions, and the material being distributed but it has been found that with a bar inner diameter of 1 inch, a slot that is ¼ inch wide and 7 inches long, and ¼ inch wide and 8.5 inches wide, respectively, is suitable (or whatever the width of the desired stripe would be). Like distribution bar  14 , distribution bars  214  and  314  may include threaded caps  258  and  358 , respectively. 
     The disclosure set forth above may encompass multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense, as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein. Similarly, where the claims recite “a” or “a first” element or the equivalent thereof, such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. 
     It is believed that the following claims particularly point out certain combinations and subcombinations that are directed to one of the disclosed inventions and are novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure.