Patent Document

RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of Ser. No. 10/884,643, filed Jul. 2, 2004 and entitled “Stripe Removal System”, the contents of which are incorporated herein in their entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to the field of high pressure water cleaning devices for highways, runways, parking decks, and other hard surfaces.  
       PRIOR ART BACKGROUND  
       [0003]     The use of paint stripes on road surfaces is the accepted method to indicate vehicle lanes, crossing lanes, parking areas and numerous other indicators. Various pavement marking techniques are known, including the use of traffic paint, thermoplastic, epoxy paint and preformed tapes. Common pavement surfaces are asphalt and concrete. Most pavement marking systems are intended to be as durable and permanent as possible, and resistant to weathering and wear from traffic. The removal of such striping is typically required when the road is to be resurfaced or if the indication is to be changed. The removal of such stripes is typically performed by use of abrasive wheels, grinding teeth, or the blasting of abrasive particles against the material to be removed. However, the use of these carbide teeth and grinding wheels results in an undesirable trench or groove in the road.  
         [0004]     When polymers such as paint are used for roadway marking, the surface of the pavement is penetrated from ⅛-⅜ inch, so that mere surface removal of the marking material is not sufficient to remove the marking. Therefore, current pavement marking removal machines often employ various forms of cutting devices to remove the marking material, as well as a portion of the underlying layer of pavement material in order to effectively remove painted lines.  
         [0005]     For example, one type of cutting machine is disclosed in U.S. Pat. No. 5,236,278 known as a “Road Pro” grinder manufactured by Dickson Industries, Inc. This type of machine employs parallel passive shafts that extend between circular rotating end plates. Hardened steel star wheels are carried on the parallel passive shafts, and these star wheels strike and abrade the pavement surface. While this type of device is effective for removal of markings, they often create excessive heat which may melt thermoplastic materials causing equipment to gum up.  
         [0006]     Another approach to pavement marking removal is the use of diamond saw blades arranged to make a dado cut. Still other types of machines use grinders or shot blast as described in patent Registrations U.S. Pat. Nos. 4,753,052; 4,376,358; 3,900,969; 4,336,671; 3,977,128 and 4,377,924. Unfortunately, these devices must remove a portion of the pavement material to effectively remove the marking, thereby leaving unsightly and potentially dangerous grooves in the pavement.  
         [0007]     NLB Corporation markets a high pressure water jet system for removing paint from pavement under the name “STARJET”. The STARJET system includes a blast head frame mounted on an attachment to the front bumper of a prime-mover truck. Casters support the frame for movement over the pavement and the path of the blast head is controlled by the driver steering the truck. Because of the position of the driver and the cab body of the prime-mover, it is difficult for the operator to see the blast head&#39;s position with regard to the stripes on the pavement. Obtaining clear vision requires the driver to lean out of the driver&#39;s side window, resulting in fatigue and other non ergonomically efficient factors. Positioning the blast head to the passenger side of the prime mover is performed manually with some difficulty and greatly complicating the driver&#39;s ability to view the path of the blast head. In addition, due to the length of the extension holding the blast head, the angular off-set, and the swivel of the casters, the movement of the wheel of the truck is not directly related to the path of the blast head further complicating operation.  
         [0008]     NLB Corporation also has another system marketed under the mark “STRIPEJET”, that is a self propelled tractor with a blast head on the front of the tractor. The blast head has a shroud and high pressure inlet without a vacuum recovery. A problem associated with the STRIPEJET device relates to the construction of the blast head mounting assembly. The mounting assembly includes a rigid track mounted transversely across the front of the tractor. This construction makes the tractor too long for transport on a truck in a transverse orientation. Transport of the tractor aligned with the longitudinal centerline of the truck requires a substantial amount of bed space, making a one truck stripe removal system impracticable.  
         [0009]     BLASTERS Corporation markets a high pressure water device which is mounted on a truck similar to the STARJET device. Yet another model appears to be a self-powered four wheeled tractor, similar to a grass mower, which supports a driver and is connected to the prime-mover by high pressure lines for delivery of high pressure water to a blast head. The blast head is mounted to the front portion of the tractor.  
         [0010]     Like the other systems currently available, the construction of the blasting head and mechanisms utilized to maneuver it prevent the tractor from being transported on a truck in a transverse orientation with respect to trucks longitudinal centerline. This construction necessitates the need to have multiple trucks and/or trailers to complete the assembly.  
         [0011]     One problem with the prior art is the inability to place a suitable amount of equipment upon the bed of a single truck to complete a marking removal task. A portion of this shortcoming stems from the inability to orient a tractor in a transverse manner with respect to the longitudinal centerline of the truck for transport. Another reason relates to the type of water and vacuum tanks utilized in the prior art. All of the known prior art utilizes cylindrical or elliptical tanks for water transport and storage, as well as vacuum recovery. As such these tanks occupy a significant amount of bed space, which obviously limits the amount of equipment that can be transported on a single truck.  
         [0012]     Marking removal systems such as those described above typically include a water tank, a vacuum tank, a high pressure water pump which utilizes an internal combustion engine, a vacuum pump which also utilizes an internal combustion engine and a tractor with a blast head. Utilization of standard water and vacuum tanks makes a single truck system impracticable. Because of this the prior art uses multiple trucks and or trailers to transport enough equipment to complete a job. Therefore, constructing a system capable of being transported on a single truck bed would provide a distinct economic advantage.  
       SUMMARY OF THE PRESENT INVENTION  
       [0013]     Briefly, disclosed is a cleaning system for removing coatings from a hard surface by high pressure liquid. The system employs a combination liquid and vacuum reservoir connected to a high pressure pump for directing ultra high pressure water through a blast head mounted on a self-propelled mobile frame. The mobile frame is a self-propelled tractor wherein the blast head and tractor are of a size for transport transversely on a truck bed. The cleaning system is preferably mounted on a single truck or in an alternative embodiment; an auxiliary water tank may be pulled behind the truck on a trailer. In either embodiment the truck is tethered to the tractor during operation. The truck bed includes a ramp sized to support the tractor for docking and transport.  
         [0014]     It is an objective of this invention to provide a vacuum recovery truck mounted stripe removal system having a compact unit for safe, fast over-the-road travel to job sites in a single truck construction.  
         [0015]     It is another objective of this invention to provide a high pressure water jet for removal of paint or other coverings and a vacuum recovery system for the water and debris being generated.  
         [0016]     It is a further objective of this invention to provide a rectangular holding tank system for a stripe removal system.  
         [0017]     It is still another objective of this invention to provide a holding tank for a stripe removal system wherein the tank system includes a water tank and a vacuum tank in a single enclosure.  
         [0018]     Still yet another objective of this invention is to provide a holding tank system for a stripe removal system wherein the vacuum tank includes a filter bag for containment of the debris generated while allowing the water to be disposed of separately.  
         [0019]     It is a further object of this invention to provide a holding tank system for a stripe removal system including a plurality of filter bag retention hooks which allow the filter bag to be retained while the tank is in generally level position while allowing the bag and any contents to be dumped by tilting the tank.  
         [0020]     It is yet another object of this invention to provide a collection/filter receptacle for the removed materials for ease of disposal and the release of filtered wastewater. This allows an operator to easily regain all of the available capacity not occupied by paint or road debris within the vacuum chamber by simply releasing a dump valve. All of the solid debris is retained until such time as the vacuum chamber is completely full. The amount of capacity able to be regained will be continually diminished as the vacuum tank fills with debris, and will eventually reach a point of inefficiency at which point it must be dumped. When the material is dumped, it is dumped as a semi-dried, dewatered debris in which the wastewater is not mixed with the debris.  
         [0021]     Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated from the following detailed description, taken in conjunction with the drawings, in which:  
         [0023]      FIG. 1  is a side view of the stripe removal system;  
         [0024]      FIG. 2  is a perspective of the stripe removal system in operation with the blast head deployed;  
         [0025]      FIG. 3  is a front view of the blast head and tractor;  
         [0026]      FIG. 4  is perspective of the articulated link;  
         [0027]      FIG. 5  is a side view of the articulated link with a portion of the boom in a stowed position;  
         [0028]      FIG. 6  is a side view of the liquid reservoir and sump;  FIG. 7  is a perspective of the vacuum tank and waste removal system;  
         [0029]      FIG. 8  is a side view of the single truck stripe removal system; and  
         [0030]      FIG. 9  is a sectional side view taken along line  1 - 1  of  FIG. 7 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]     The paint removal system  10 , shown in  FIG. 1 , includes a prime-mover truck  11  and a trailer  12 . The truck has a forward cab-over  18  for the driving controls and operator. Mounted on the bed  81  of the truck is the water reservoir  13  and the sump  14  or vacuum chamber. The reservoir and sump are interconnected by a strategically positioned duct for continuous dumping of filtered wastewater when operating from a fixed position where liquid is supplied to the high pressure pump by a means other than the reservoir  13 .  
         [0032]     The sump  14  is positioned on the rear portion  82  of the bed  81 . The rear portion  82  of the bed is pivotally mounted on the truck frame and hydraulicly powered to tilt in the vertical plane permitting dumping of the contents of the sump  14 . The sump  14  is connected to the vacuum pump  15  by hose  16 . The intake of a high power vacuum pump capable of approximately 1100 CFM (cubic feet per minute) is connected to the vacuum tank. The vacuum tank and pump are also mounted on the bed  81  of the prime-mover  11 .  
         [0033]     A ramp  19  is hinged to the edge of the bed  81  between the vacuum pump  15  and the cab  18 . The ramp can be lowered to provide a pathway for the self propelled tractor  20  ( FIGS. 2 and 3 ). As shown on  FIGS. 1 and 8 , the ramp  19  is in the stowed or traveling position for highway transport. When the ramp is unfolded it is approximately 9 feet in length.  
         [0034]     The trailer  12  is removably attached to the prime-mover through a conventional trailer hitch  21 . Mounted on the bed  81  of the trailer is a high pressure fluid pump greater than 25,000-40,000 psi and from 2-15 gallons per minute. A high pressure hose connects the pump with the blast head during operation.  
         [0035]     Referring to  FIG. 8 , a single truck unit is illustrated eliminating the need for a trailer. The single truck unit includes a prime-mover truck  11 . The truck has a forward cab-over  18  for the driving controls and operator. Mounted on the bed  81  of the truck is the holding tank  75  including the water reservoir  13  and the vacuum chamber or sump  14 . The reservoir and vacuum chamber are interconnected by a strategically positioned duct  64  for continuous dumping of filtered wastewater when operating from a fixed position where liquid is supplied to the high pressure pump by a means other than the reservoir  13 .  
         [0036]     The sump  14  is positioned on the rear portion  82  of the bed  81 . The rear portion  83  of the holding tank  75  is pivotally mounted on the truck frame and hydraulicly powered to tilt in the vertical plane permitting dumping of the contents of the vacuum chamber  14 . The vacuum chamber  14  is connected to the vacuum pump  15  by hose  16 . The intake of a high power vacuum pump, capable of approximately 1100 CFM (cubic feet per minute), is connected to the vacuum tank. The vacuum tank and pump are also mounted on the bed of the prime-mover  11 .  
         [0037]     Also mounted on the bed  81  of the truck is a high pressure fluid pump  76  capable of producing 25,000-40,000 psi at 2-15 gallons per minute. A high pressure hose connects the pump with the blast head during operation.  
         [0038]     This embodiment may also include a ramp  19  hinged to the edge of the bed  81  between the vacuum pump  15  and the cab  18 . The ramp can be lowered to provide a pathway for the self propelled tractor  20 . As shown in  FIG. 8 , the ramp  19  is in the stowed or traveling position for highway transport. When the ramp is unfolded it is approximately 9 feet in length and constructed of a material suitable for traverse by a tractor.  
         [0039]     In  FIG. 2  the mobile tractor  20  is illustrated in the normal operations position. The tractor is similar to a riding mower with a small engine self propelling the tractor. The blast head  23  has at least one and up to sixteen high pressure nozzles delivering high pressure fluid to the surface to be cleaned. The high pressure nozzle is carried on a chassis  24  mounted on casters  25 . A shroud  27  descends from the chassis and surrounds the high pressure nozzle. The blast head is connected to the high pressure fluid pump by high pressure hose  26  and the shroud  27  is connected to the vacuum chamber by vacuum hose  28 . The high pressure hose  26  and the vacuum hose  28  is supported by a swinging boom  29  which is mounted on the prime mover  11  shown in  FIG. 1  to provide freedom of movement for the tractor and to prevent tangling or running over of the hoses by the prime mover.  
         [0040]     As shown in  FIGS. 3-5 , the blast head  23  is connected to the tractor  20  by an articulated link  31  which is capable of horizontal movement, as shown in  FIGS. 3 and 4 , and vertical movement, as shown in  FIG. 5 . A bar  32  is attached to the tractor frame by rods  33  and  34 . The bar  32  is located between the front wheels of the tractor. The horizontal swinging movement of the link results in a widened path of the high pressure nozzle to adjust for different widths or patterns of striping of the surface being cleaned and deviations in direction of the tractor. The horizontal movement is powered by the hydraulic cylinder  35  connected to the bar  32  which may be controlled by the operator moving a joy stick on the tractor. The hydraulic piston  36  is connected to the trailing arms  37  and  38  so that the trailing arms rotating about pins  39  and  40  attached by brackets  41  and  42  on bar  32 .  
         [0041]     The forward end of the articulated link  31  has a plate  43  connected to the forward ends of trailing arms  37  and  38 . The arms  37  and  38  are rotatably connected to the plate by brackets  41 ′ and holding pins  39 ′,  40 ′, respectively. The forward arms  44  and  45  are rotatably connected to the plate  43  to rotate vertically. Pins  46  and  47  extend horizontally through brackets  48  and  49 . Another hydraulic cylinder  50  is connected to the plate  43 , and the piston  51  is connected to the forward end of the arm  44 . As the piston  51  moves, the distance between the surface to be cleaned and the blast head  23  changes. The vertical movement permits elevation changes to accommodate the contours of the surface. Further, the blast head  23  may be raised to the vertical position and then manually flipped up and back reducing the overall length to permit the tractor  20  and blast head  23  to be stowed on a truck bed sideways consuming a space of less than 8′ 6″ for highway travel, shown in  FIG. 5 . This arrangement also facilitates the operator examining the nozzles and the rotating assembly of the blast head from the operating position. The forward ends of the arms  44  and  45  are attached by pins  52  and  53  to brackets  54  and  55  to prevent binding as the arms are manipulated. The brackets are mounted on a blast head attachment plate  56 .  
         [0042]     A blast head attachment plate  56  is removably connected to the chassis  24  of the blast head  23  to provide support and control of the blast head from the tractor through the link  31 .  
         [0043]     The holding tank  75 , including the liquid reservoir  13  and the vacuum chamber  14 , is shown in  FIG. 6 . As illustrated, the liquid reservoir and vacuum chamber have a common enclosure with an internal partition dividing them. The vacuum chamber  14  has an inlet  57  for connection by hose  28  to the vacuum shroud  27 . An outlet  58  is connected to the vacuum pump hose  16 . The liquid reservoir has a hatch  60  for inspecting and cleaning the reservoir with approximately 600-1500 gallons of liquid. An outlet  61  is connected to a low pressure pump by a low pressure suction hose  62 . The low pressure 12-volt pump (not shown) may be used to pump water out of the reservoir  13  back to the high pressure pump  76  at about 40 psi and up to 20 g.p.m. A recycling valve  63  is mounted in a connector pipe  64  having one end opening into the reservoir  13  and the other end opening into the sump  14 . The connector is located near the bottom of the vacuum chamber and reservoir to allow for some settling of debris in the vacuum chamber. The valve  63  opens or closes the connection.  
         [0044]     Referring to  FIGS. 7 and 9 , the vacuum chamber  14  is shown with the rear door  65  open for unloading the porous enclosure  84 . The door includes a seal (not shown) to maintain the negative pressure therein during operation. The porous enclosure may be a wire screen or mesh box sized to fit within the vacuum chamber  14 . In an alternative embodiment shown in  FIG. 9 , the porous enclosure is replaced by a plurality of perforated plates  77 . The perforated plates are secured to an inner surface of the sump panels with stanchions  78 . Wire mesh or expanded metal may be utilized in place of the perforated plates without departing from the scope of the invention. An additional filter bag  79  having between 5-200 micron porosity may be inserted into the porous enclosure  64 . Alternatively, the filter bag may be supported in a substantially open position utilizing a plurality of hooks  80  secured to an inner surface of the vacuum chamber. The hooks are preferably constructed and arranged to secure the bag while the sump is in a level position while allowing the bag and any contents to be automatically released when the sump is in a tilted position. It should also be noted that the hooks could be replaced with other mechanical or mechanical/electrical means suitable for retaining the bag in an open position during use while allowing the bag and any contents therein to be automatically released for disposal thereof.  
         [0045]     The dimensions of the porous enclosure  64  are somewhat less than the interior of the vacuum chamber which provides a marginal area  85  between the porous enclosure and the interior walls and floor of the vacuum chamber which provides an exit path for filtered water through valve  70 . The inlet  57  empties into the porous enclosure  64 , thereby preventing coatings from being entrained in the vacuum system. One side of the holding tank enclosure is hinged and latched to permit entry into the vacuum tank or removal of the filter bags. By opening the vacuum chamber door and raising the dump bed of the truck, the waste material can be easily and quickly removed without prolonged interruption of the operations. The filter bag is the disposal container, and is dumped with the material. A permanent filter material can also be utilized which requires cleaning after each use but does not waste a filter bag each time it is dumped.  
         [0046]     In operation, the process for using the disclosed equipment in a mobile operation for stripe removal:  
         [0047]     1. Connection valve  63  remains closed. Water tank  13  is used only as a fresh water supply and is not placed under vacuum at any time.  
         [0048]     2. Filter material  84  positioned in the vacuum tank at a distance off the walls and floor of the tank. A filter “bag”  79  may also be hung by hooks  80  from the top panel to produce even cleaner waste water.  
         [0049]     3. The vacuum tank or sump  14  is placed under vacuum by starting the diesel powered vacuum pump which is connected by an air outlet hose  57  to the vacuum tank.  
         [0050]     4. As stripe material is removed creating a slurry of water and debris, the mixture is drawn through the inlet hose into the vacuum tank being trapped in the filter.  
         [0051]     5. When the vacuum tank reaches its full capacity, a shutoff ball  86  is forced upwards toward the air outlet hose and makes contact with a ball seal  87  causing loss of tank vacuum.  
         [0052]     6. The drain valve  70  is then opened on the vacuum tank. The drain permits water to drain through the filter material and into the open cavity between the walls and floor allowing an exit from the drain.  
         [0053]     7. The connection valve  63  is closed allowing for a capacity equal to the capacity previously occupied by dirty water, only the debris slurry remains inside the tank.  
         [0054]     8. Steps 1-7 are repeated until the strip is removed.  
         [0055]     9. Opening of a door to the vacuum container, allows for a removal of all debris captured in the filter.  
         [0056]     The instant invention may also be used in a non-mobile setting in continuous operation as follows.  
         [0057]     1. The connection valve  63  remains open except when it is necessary to dump the water tank. The water tank is used as an overflow vacuum tank and is under vacuum much of the time.  
         [0058]     2. Filter material  84  is positioned in the vacuum tank at a distance off the walls and floor of the tank. A filter “bag”  79  may also be hung by hooks  80  from the ceiling to produce even cleaner waste water.  
         [0059]     3. Vacuum tank or sump  14  is placed under vacuum by starting the diesel powered vacuum pump which is connected by the air outlet hose  57  to the vacuum tank. The water tank  13  is under vacuum as well by way of connection valve  63 .  
         [0060]     4. As stripe material is removed, creating a slurry of water and debris, the mixture is drawn through the inlet hose into the vacuum tank being trapped in the filter.  
         [0061]     5. As the debris and water level rise to the level of the connection valve, the water will begin flowing through the connection valve into the water tank. The water in the water side tank will be filtered water as the water has had to first flow through the filter material to reach the connection valve.  
         [0062]     6. When the waste water has reached the level of the connection valve it will be visible to the operator through a strategically positioned sight glass. At that point, without shutting down the vacuum or the operation, the operator closes the connection valve which releases the water side tank from vacuum.  
         [0063]     7. Next, the operator must open the drain valve on the water tank to release the waste water being held there.  
         [0064]     8. After the water tank has drained completely, the water side drain valve must be closed.  
         [0065]     9. The connection valve is reopened allowing wastewater to flow freely into the water tank.  
         [0066]     10. Repeating of steps 1-9 while never shutting down or affecting the blasting operation whatsoever. This may be continued until the vacuum tank is full of debris.  
         [0067]     11. It is now necessary to shut off the vacuum power unit and open the drain valve on the vacuum tank. This allows the water to drain through the filter material, into the open cavity between the walls and floor, and exit the drain. This allows the debris to dewater.  
         [0068]     12. Opening of the vacuum door allows for a release of all material to repeat the process.  
         [0069]     A number of embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiment but only by the scope of the appended claims.

Technology Category: 0