Patent Application
20180030678
Embodiments herein relate to the application of marking indicia to roadways and runways.
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.
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.
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.
One form the apparatus for applying the marking indicia may take is that depicted in
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
Valve 20 may include a valve seat 24 which is designed to receive a ball valve 26 as shown best in
Cylinder 32 may have a reciprocable piston 34 therein (See
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
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
As best shown in
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
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.
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.
| Number | Date | Country | |
|---|---|---|---|
| 62369429 | Aug 2016 | US |
