Abstract:
The invention generally relates to a surface treatment distribution apparatus and spray assembly apparatus method capable of applying a variety of surface treatments, for example mastic surface treatments, to a variety of highways, roadways and other asphalt surfaces of variable shapes and sizes. The invention generally includes a tank, pumps, operator station, control inputs, filter assemblies, spray bar and self cleaning spray tip assemblies. Each spray tip assembly includes a self cleaning functionality whereby the operator may remove any debris or clogging material from one or more spray tips with a pneumatically actuated plunger located in the spray tip assembly that acts to force the debris or blockage out of the spray tip. The plunger retracts after actuation and the spray tip assembly is then ready to resume spray operations as desired by the operator.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of and priority to U.S. provisional application, Ser. No.61/829,314, filed on May 31, 2013, the disclosure of which is incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not Applicable 
       INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0004]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    The present invention relates generally to apparatus and methods for applying a surface treatment to roadway surfaces and more specifically to a truck mountable surface treatment distributor apparatus and method providing the operator with control of the application rate of the product in real time as the surface treatment is being applied. The present invention also relates to apparatus and methods for cleaning the applicator spray tips so as to easily maintain the spray apparatus and prevent clogging of the applicator apparatus over repeated usage. 
         [0006]    Asphalt surface treatments are applied to asphalt roadways and surfaces mainly as a preventative maintenance procedure to prevent or delay degradation of the road surface from environmental exposure to rain, snow, and thermal temperature variations. Surface treatments are also applied to enhance the wearing properties of the roadway and to improve fraction between the vehicle tires and the roadway. 
         [0007]    Generally, asphalt surface treatments are composed of a thin layer of asphalt material made from an asphalt emulsion, cutbacks or asphalt cement. Mastics and/or other modifiers may be added to liquid asphaltic mixture and may include rubber, latex, and polymers. Additional additives such as sand, aggregate, fillers and rubber crumbs may applied after the asphaltic mixture is applied to the pavement surface. In other known sealing methodologies, certain seal coats such as slurry seals, utilize aggregates and fillers that are combined in the seal coat mixture prior to application on the asphalt surface. 
         [0008]    Asphalt surface treatments are typically applied by a distributor spray system such as a truck mounted system with multiple spray applicators or “spray tips” attached to a spray bar mounted on the rear of the truck. The fluid or surface treatment to be applied to the roadway is stored on a tank mounted to the truck and drawn from the tank through a pump and into the spray bar and shot or emitted as a spray from the spray tip nozzles in a downward direction and on to the road surface. The spray applicators are in fluid communication with a manifold and the pressure within the manifold is controlled by a control panel so that the operator may control and adjust the rate of fluid application to the road surface. However, in most if not all applications, the application of surface treatments to a roadway surface requires intermittent spraying and actuation of the system due to environmental working conditions or to allow for treatment of certain areas of the roadway. For example, during periods of high winds spraying of a roadway surface may result in the surface treatment being blown out of the desired coverage area or being substantially dispersed in the air. As such, it is not cost effective to continue spraying operations until environmental conditions become more favorable spray operations that can change within minutes. As the truck is on site, yet not conducting spray operations, the surface treatment may which is in a liquid state may begin to congeal and thicken resulting in the formation of agglomerated particles into small chunks of hardened material that can result in the partial stoppage and clogging of the spray system and spray applicators. Also, if the spraying system is not cleaned or flushed soon after spraying operations are stopped or completed, the spraying application system and spray applicators may become clogged which substantially reduces the ability to conduct spray operations until the system and equipment are flushed or cleaned at a maintenance facility. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The invention generally relates to a surface treatment spray system apparatus and method capable of applying a variety of surface treatments, for example mastic surface treatments, to a variety of highways, roadways and other asphalt surfaces of variable shapes and sizes. The invention generally includes a tank mounted on load cells secured to a subframe assembly. The subframe assembly mounts to a standard truck chassis or, in other embodiments, a trailer or other vehicle. The spray system also includes a tank, pumps, operator station, compressed air source, control inputs, primary filter assemblies, secondary filter assemblies, spray bar and self cleaning spray tips in fluid communication via rigid, semi-rigid or flexible piping connections rated for pressurized operations. A global positioning system (GPS) may be integrated with the system to provide accurate speed and distance information associated with the system while in use and calibrated scales for tracking product weight(s) before, during and after operation of the system and to provide weight differential data during operation of the system. 
         [0010]    Spray tip assemblies, also referred to herein as spray tips, include a self cleaning functionality whereby the operator may remove any debris or clogging material from one or more spray tips with a pneumatically, or by other pressure induced means, actuated plunger located inside of each spray tip that acts to force debris or other blockage out of the spray tip. The plunger retracts and the spray tip is then ready to resume spray operations as desired by the operator. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Various other objects, features and attendant advantages of the present invention will become fully appreciated, as the same becomes better understood when considered in conjunction with the accompanying drawings and photographs of the invention. 
           [0012]      FIG. 1  is a perspective view of a vehicle and spray system incorporating the invention disclosed herein for applying a liquid surface treatment to a roadway; 
           [0013]      FIGS. 2A and 2B  is a rear view of the vehicle and spray system incorporating the invention disclosed herein with spray bar extensions folded and unfolded, respectively, for additional coverage operations; 
           [0014]      FIG. 3  is a side view of the vehicle and spray system incorporating the invention disclosed herein; 
           [0015]      FIG. 4  is a rear perspective view of the vehicle and spray system incorporating the invention disclosed herein depicting the pumps, filters and spray bar with spray tip assemblies; 
           [0016]      FIG. 5  is an exploded view of a spray tip assembly depicting the components of the spray tip assembly according to the invention disclosed herein; and, 
           [0017]      FIGS. 6A and 6B  are depictions of the lower guide assembly of the spray tip assembly and the self-cleaning mechanism for each spray tip assembly according to the invention disclosed herein. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    As described herein and shown in the accompanying Figures, the inventive embodiments described and shown herein disclose an apparatus and method for applying, in one embodiment, an aggregate filled asphalt-emulsion coating designed to add friction and wear surfaces to an existing asphalt surface. As shown in  FIG. 1 , the spray system  10  is mounted to a truck  12  or other capable vehicle or trailer apparatus and provides operator controlled application rates or “shot” rates of the coating product. In certain applications, the shot rate is typically applied to the asphalt surface at 0.1 gallons per square yard per shot. Additionally, the apparatus and method disclosed herein provide variable shot rate control by the operator in real time during application processes. 
         [0019]    The elements of the invention include a tank  14  with a paddle agitator contained therein (not shown) for agitating the mastic emulsion surface treatment or other spray fluid contained in the tank and to keep the spray fluid in suspension while residing in the tank. The tank  14  may be made from steel, plastics or other materials of sufficient strength and durability for use with mastics and other asphaltic sealing materials. A hatch  16  is provided for access to the interior of the tank  14  to allow for filling of the tank  14  or inspection of the tank  14 . In one embodiment, the paddle system agitator is hydraulically powered and is capable of being rotated bi-directionally. In an embodiment, the tank  14  is mounted on load cells and secured to a subframe assembly. The load cells transmit measurable electrical data to a scale head that converts the load data transmitted from the load cells to weight measurements enabling the operator to collect and process data related to specific job production as is known in the art. The subframe assembly is mountable to truck  12 , such as a Class  8  truck chassis, or any other mobile platform capable of supporting the invention assembly as disclosed herein. 
         [0020]    As shown in  FIGS. 1 and 4 , a first pump  20  and a second pump  22  comprising in one embodiment single acting piston/plunger pumps capable of producing a flow rate of up to 100 gallons per minute are in fluid communication with the tank  14  via hydraulic piping and hoses providing a fluid communication system to the elements of the invention disclosed herein. The first and second pump units  20 , 22  provide sufficient pumping force to pressurize, transport and dispense the spray fluid contained in the tank  14  throughout the fluid communication system connecting the tank  14 , pumps  20 ,  22 , filtration assemblies  24 ,  26 , spray bar  30 , and self-cleaning spray tips  32  at the rates and pressures desired by the operator and controlled by the operator stationed (sitting or standing) on platform  28  from control panel  18  for determining the shot rate for application of the fluid surface treatment to the pavement surface. The spray fluid communication system (including but not limited to hosing  40 , spray bar  30 , spray feed tubes  31  and recirculation hoses  38 ) provides the pathways for the flow of fluids through the system utilizing sufficient pressure rated hosing and/or metal piping as is known in the art. Although not shown in detail, one of ordinary skill in the art may easily configure the pneumatic and/or hydraulic components and communication system necessary to supply and operate the identified pneumatic and hydraulic components of spray system  10  as described hereinafter. 
         [0021]    A primary filter assembly  24  is in fluid communication with the tank  14  and first pump  20  which provides fluid from tank  14  to primary filter assembly  24  so as to filter out agglomerated clumps or off-size materials suspended in the mastic fluid which might clog, degrade or otherwise inhibit operation of the fluid communication system, pumps  20 ,  22  or one or more spray tips  32  located on the spray bar  30 . One or more secondary filter assemblies  26  are positioned downstream of the first pump  20  and upstream of the spray bar  30  and spray tips  32 . The secondary filter assembly  26  acts to remove suspended particles in the fluid which are of sizes small enough to pass through the primary filter assembly  24  and such particles remaining of sizes sufficient to clog or inhibit the flow of fluid (e.g. mastic) to and through the spray bar  30  and spray tips  32  located thereon. 
         [0022]    In certain contemplated embodiments, the first pump  20  and primary filter assembly  24  provide fluid to the spray bar  30  with second pump  22  and secondary filter assembly  26  remaining offline as a backup system for providing fluid to spray bar  30 . In certain contemplated embodiments, pumps  20 ,  22  and filter assemblies  24 ,  26  may operate as separate systems for providing fluid to the spray bar  30  in a series or parallel fluid communication system design. It is contemplated that the pumps  20 ,  22  and filter assemblies  24 ,  26  may be interconnected as desired by the user or as dictated by the application to provide and filter spray fluid to the spray bar  30  and spray tips  32  in a parallel or series fluid communication system from which spray fluid is pumped from tank  14  and ultimately to spray tip assemblies  32  via spray bar  30 . One of ordinary skill in the art will recognize the various fluid communication pathways and networks which may be utilized with the apparatus and method disclosed herein and any particular network described herein is not to be construed as a limitation to any such other contemplated embodiments. 
         [0023]    The primary and secondary filter assemblies  24 ,  26  generally comprise a closeable box enclosure with a screen basket filter contained therein providing for pressure filtration of the fluid that is being pumped out of the tank  14  and through to the spay bar  30  and spray tips  32  for spraying on to a roadway surface. In one embodiment, the sieve size of the primary screen filter element is about ⅜ inches, while the sieve size of the secondary screen filter element is about 3/16 inches. In one embodiment, the screen size of the primary screen filter element is larger than the sieve screen size of the secondary screen filter element. The sieve size of the primary and secondary screen filter elements  24 ,  26  may be sized according to the fluid being applied to the pavement surface and the particle types and sizes suspended in the fluid. The lids of the primary and secondary filter assemblies  24 ,  26  are removable to facilitate removal and replacement of the filter screens for cleaning and maintenance. 
         [0024]    A spray fluid recirculation circuit is also provided to provide for circulation of the spray fluid while spraying operations have temporarily been stopped. First pump  20  and second pump  22  draw spray fluid from tank  14  into hosing  40  for provision to the spray bar  30  and ultimately to spray tips  32  for deposit on to the roadway. When spraying operations are temporarily stopped, the operator who is located on the operator platform  28  may configure the system  10  via control panel  18  to remain pressurized and recirculate spray fluid drawn from the tank and through pump  20  and/or pump  22  to return spray fluid into tank  14  via valves  39  that direct the fluid flow to the recirculation hosing  38  from pump  20  and/or pump  22  and back into tank  14 . In this manner, the spray fluid remains moving and pressurized in the system and such recirculation acts to inhibit coagulation or formation of hardened spray fluid nodules from forming when spraying operations are temporarily ceased. Likewise, the system remains in a pressurized state and when spraying operations are to be resumed the operator actuates valves  39  to direct spray fluid to the spray bar  30  via hoses  40 . In an embodiment, spray fluid in spray bar  30  is also in fluid communication with pump  20  and/or pump  22  and is recirculated to tank  14  via the fluid communication system. 
         [0025]    After spraying operations are complete, the operator may flush and clean the fluid communication system, pumps, filter assemblies and spray tips by pumping water (or other cleaning solvents or fluids as may be desired) from a storage tank (not shown), which is located on the truck  12  or from another external source, through the fluid communication system for rinsing and cleaning the piping and hoses, valves, pumps, filters and spray tips of the spray system  10 . This prevents any remaining spray fluid from drying out and hardening within the equipment components and fluid communication system that would degrade or inhibit the operation and performance of the invention disclosed herein. 
         [0026]    As shown in  FIGS. 2A ,  2 B and  3 , spray bar  30  includes folding spray bar extensions  34 ,  36  which are in fluid communication with the tank  14 , pumps  20 ,  22  and filter assemblies  24 ,  26 . Spray bar  30  includes multiple spray tips  32  attached to the spray bar  30  by spray feed tubes  31 . Spray tips  32  emit and direct the spray fluid or other desired fluid on to an asphalt pavement or roadway surface as further described herein. As seen in  FIG. 3 , spray tips  32  receive fluid to be sprayed on to the roadway from spray feed tubes  31  which provide fluid communication between the spray bar  30  and lower chamber of each spray tip  32  (shown and described in  FIGS. 4 and 5 ). A spray feed tube valve (not shown) is included with each individual spray feed tube  31  and positioned between the spray bar  30  and each spray tip  32 . The spray feed tube valves are actuated (either opened or closed) by valve actuator  33  that is controlled hydraulically, pneumatically, electronically or by other means as known in the art by the operator from control panel  18 . Spray feed tubes  31  are secured to the spray bar  30  and spray tips  32  at nipple  72  as shown in  FIGS. 6A and 6B  located on the lower chamber  64  depicted in  FIG. 5  for ease of maintenance and replacement as needed. In an embodiment, spray feed tubes  31  are welded to spray bar  30  so as to provide a stable and rigid support for spray tips  32 . In other contemplated embodiments, spray tips  32  may be supported and connected to spray bar  30  by other means as known in the art such as rigid frames, extension arms or supports connected to spray bar  30  and to which spray tips  32  are secured. 
         [0027]    When spray system  10  is pressurized and ready for operation, the desired fluid supply valves (not shown) which are located in each spray feed tube  31  are opened by the operator as described above allowing spray fluid to be emitted from each corresponding spray tip  32  and sprayed on to the roadway surface. When in the closed position, the supply valves prevent the emission of spray fluid from the spray tips  32 . In one embodiment, spray bar  30  is about eight feet in length with multiple spray tips  32  fed by individual spray feed tubes  31  spaced about 9.25 inches apart on the spray bar providing for the inclusion of eleven spray tips  32 . It is contemplated that various dimensions of spray bar length may be sized and manufactured for various applications and the dimensions provided herein are not to be construed as limiting. 
         [0028]    As seen in  FIG. 2A , two spray bar extensions  34  are shown in a retracted or folded up position.  FIG. 2B  shows the spray bar extensions  34  folded down in the ready position for spray operations to commence. Spray bar extensions  34  are rotatably attached to and in fluid communication with the spray bar  30  via hosing  40  (see  FIG. 4 ) allowing the operator to use one or both of the spray bar extensions  34  to extend the width of spray coverage to be deposited on to the pavement surface. The height of the spray bar  30  above the roadway surface is adjustable from between about sixteen to twenty-four inches from the ground via hydraulic or pneumatic cylinders  36  which are connected to spray bar  30  via frame  37  and which act to elevate or lower the spray bar  30  as desired by the operator from control panel  18 . In one embodiment, spray bar extensions  34  are hingedly connected to the spray bar  30  so as to allow the spray extensions  34  to be folded up or down via as desired by the operator from the control panel  18  for the task at hand. Folding spray bar extensions  34  provide for the ability to vary the width and/or length of the spray pattern as the pavement surface to be sprayed may vary in width and/or length. 
         [0029]    Turning to FIGS.  5  and  6 A- 6 B, the components of spray tip assemblies  32  are shown in greater detail. Each spray tip assembly  32  includes a self-cleaning mechanism whereby any aggregate or other agglomeration of particles and debris in the mastic spray or fluid which act to clog the lower chamber of spray tip  32  may be removed by the actuation of a plunger  48  which acts to force the blocking debris  82  out of the lower chamber of spray tip assembly  32 . As shown in  FIG. 5 , spray tip assembly  32  includes an upper chamber assembly  42 , middle guide assembly  62  and lower assembly  64 . Upper chamber assembly  42  operates to provide an enclosure for imparting a force generated by pressurizing the upper chamber assembly  42  pneumatically with compressed air (received from a compressed air source in communication with upper chamber assembly  42 ) entering upper chamber assembly  42  via an air port  45  with enough force imparted by an air diaphragm (not shown) on to plunger disc  50  of plunger  48  that drives plunger  48  downwards, and partially through and out of the spray tip assembly  32  to remove any debris  82  clogging and inhibiting or otherwise preventing the flow of fluid from the spray tip assembly  32 . When the pressurization of upper chamber assembly  42  is released and it proceeds back to a rest or atmospheric pressure state from an exhaust valve (not shown) located in one of the air ports  45 , plunger  48  retracts due to the force imparted by spring  52  kept in tension by spring tension spacer  54 . Plunger tip  49  retracts above the fluid inlet orifice  80  (the plunger tip  49  retracts above the orifice  80  provided in nipple  72 ) which is in fluid connection with spray feed tube  31  (shown in  FIG. 2C ) that provides the spray fluid to be sprayed by spray tip assemblies  32 . Plunger  48  may be actuated to extend and retract on an as needed basis by the operator or may be programmed to cycle at certain periods as desired by the operator. Upper chamber assembly  42  includes a top housing  44  with air ports  45  providing for the inlet and outlet of pressurized air for imparting a force to plunger  48  via an air diaphragm housed within the upper chamber assembly  42 . 
         [0030]    Bottom housing  46  is releasably connected and sealed with a gasket (not shown) to top housing  44  with clamp  56  which is tightened/loosened with bolt or screw and nut connectors  58 . Such design enables the user to easily access, maintain and repair the upper chamber assembly  42 . Top housing  44  and bottom housing  46  may be fabricated from any material suitable for rugged environmental operations including stainless steel and other suitable metals and materials as known in the art. One or more threaded studs  60  are provided on the bottom surface of bottom housing  46  which allow for middle guide assembly  62  to be attached to the bottom housing  46  with nut connectors  70 . Bottom housing  46  includes an orifice of sufficient diameter (not shown) and positioned to align with orifice  74  in middle guide assembly  62  and through which plunger  48  may extend and move in the axial direction through corresponding orifices  74  in the middle guide assembly  62  and lower chamber  64  as shown in  FIGS. 5 and 6B . 
         [0031]    Middle guide assembly  62  is a machined metal component that acts to connect the upper chamber assembly  42  with the lower assembly  64  which includes a machined tubular barrel or orifice  74  through which plunger  48  moves in a bi-directional axial fashion to push debris  82  out of lower chamber  64  as seen in  FIGS. 5 and 6B . In certain applications, middle guide assembly  62  may be manufactured from any material suitable for rugged environmental operations including stainless steel and other suitable metals and materials as known in the art. Middle guide assembly  62  attaches to the upper chamber assembly  42  via threaded connection at studs  60  and nuts  70 . In an embodiment, lower chamber  64  consists of a machined metal component that includes an o-ring (not shown) that is compressed between the middle guide assembly  62  and lower chamber  64  when bolts  66  and nuts  68  are tightened to connect the middle guide assembly  62  and lower chamber  64  together. The O-ring seal acts to prevent the spray fluid from entering into the upper chamber assembly  42  and middle guide assembly  62 . As shown in  FIG. 6A , lower chamber  64  includes a nipple  72 , such as in one embodiment a #12 JIC 37 degree threaded flare nipple, that provides an attachment point for spray tip assembly  32  to the spray bar  30  via spray feed tube  31  (which can be a rigid or flexible pipe or hose) which includes fluid supply valve  31 , and provides a fluid pathway for feeding the spray fluid from the spray bar  30  to lower chamber  64  for dispersion on to the roadway or pavement. In one embodiment, a steel spray tip (not shown) may be threaded into the bottom of lower chamber  64  which provides a degree of interchangeablity so that a user may install different spray tips which provide a different spray pattern as desired. In certain applications, lower chamber  64  may be manufactured from any material suitable for rugged environmental operations including stainless steel and other suitable metals and materials as known in the art. 
         [0032]    Operator&#39;s control station  18  includes the controls and electronics necessary to operate the inventive apparatus described herein. The operator&#39;s control station  18  includes hydraulic, electric, and pneumatic controls for operation of the spray system  10  described above. In an embodiment, the hydraulic controls operate the position of the spray bar (up and down), the agitator in the tank (forward/reverse direction), the water pump (on/off), the first and second fluid pumps (on/off), actuation of the valves in the spray feed tubes controlling the flow of spray fluid from the spray bar to the spray tip assemblies and the pressure valves for the first and second pumps. The electric controls operate the first and second pumps, the air compressor source, and the work lights stationed on and around the operator&#39;s station and vehicle. The pneumatic controls are utilized for actuating the spray tip cleaning operation as described herein. 
         [0033]    The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention in which all terms are meant in their broadest, reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.