Abstract:
A self-propelled mobile marking removal system which comprises a mobile vehicle assembly including a chassis, a high pressure liquid pump in fluid connection with a liquid reservoir contained within said chassis, said high pressure liquid pump is further in fluid connection with a blast head, said blast head having at least one high pressure nozzle for delivering liquid at high pressure to a marked surface, a waste removal hose fluidly coupled with said blast head and a sump for collection of liquid and debris, said blast head positionable along a left or a right side of said chassis, a mechanical abrasion means, said mechanical abrasion means positionable along a left or a right side of said chassis in front of said blast head, said mechanical abrasion means is constructed and arranged to substantially remove marking material protruding above said marked surface and said blast head constructed and arranged to substantially remove any marking material extending below said marked surface. As a result of this arrangement the self-propelled vehicle can travel at speeds up to approximately 25 MPH.

Description:
RELATED APPLICATIONS 
   This application is related to application Ser. No. 10/884,643, filed Jul. 2, 2004, entitled “Stripe Removal System”; Ser. No. 11/340,104, filed Jan. 26, 2006, entitled “Mobile Mark Removal System”; Ser. No. 11/340,738, filed Jan. 26, 2006, entitled “Transportable Holding Tank For Stripe Removal system” and U.S. patent application filed Mar. 3, 2006, U.S. Express Mail No. EV531127420US, entitled “Articuable Arm for Mark Removal System” the contents of which are herein incorporated by reference. 
   FIELD OF THE INVENTION 
   This invention relates to the field of high pressure water cleaning devices for highways, runways, parking decks, and other hard surfaces. 
   PRIOR ART BACKGROUND 
   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 well known in the art, including the use of traffic paint, thermoplastics, epoxy paints and preformed tapes. Most pavement marking systems are intended to be as durable and permanent as possible, and resistant to weathering and wear from traffic. Common road surfaces are asphalt and concrete. The removal of such striping is typically required when the road is to be resurfaced or if the indication is to be changed. 
   When polymers such as paint or plastic 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. 
   Commonly known methods for removal of such markings typically include the use of abrasive grinding wheels, material removing cutters, or blasting of abrasive particles against the material to be removed. However, the use of these devices often results in undesirable grooves in the pavement surface. 
   For example, one type of cutting machine is disclosed in U.S. Pat. No. 5,236,278 known as “Road Pro” 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, it often creates excessive heat which may melt thermoplastic materials causing equipment to gum up. Also, since markings may sometimes penetrate below the surface of the roadway, as in the case of an asphalt roadway, a portion of the pavement surface must be removed to remove the marking. This results in excessive debris, slower operating speeds and a grooved surface that must be repaired. The instant invention avoids these problems by employing a combination abrader and high pressure fluid nozzle to remove the markings without penetration of the surface of the roadway. 
   Another approach to pavement marking removal is the use of diamond saw blades or cutters arranged to make a dado cut. Still other types of machines use grinders or shot blast as described in 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. They also generate a large amount of abraded dust and particulate matter from the road surface which is either dispersed into the air or remains along the road surface requiring further cleaning. The instant invention overcomes these problems by capturing all the dust and debris that is generated by the strip removal process. Since the invention removes the final amount of striping with high pressure liquid, there is no damage to the surface of the roadway. 
   It is also known in the prior art to utilize high-pressure water jets to remove markings from pavements. The instant inventor teaches a Stripe Removal Systems in U.S. patent application Ser. Nos. 10/884,643; 11/340,104 and 11/340,738, the contents of which are incorporated herein in their entirety. In addition, NLB Corporation markets a high pressure water jet system for removing paint from pavement under the name “STARJET”. BLASTERS Corporation markets a high pressure water device which is mounted on a truck similar to the STARJET device. 
   The most common problem associated with these prior art devices is the removal of a portion of the pavement material during removal of the markings. If the entire road surface was going to be paved afterwards, this would not present a problem. However, if the road surface or parking lot was not going to be subsequently paved these prior art systems would leave unsightly and potentially dangerous grooves in the road surface or pavement which would have to be repaired prior to its being open to traffic. This repair involves a timely and costly filling in of the grooves. 
   The use of high powered water jet systems to remove striping or paint from a roadway surface or parking lot overcomes the problem of abrading away the top layer of the roadway surface and leaving grooves. These systems use a very large amount of water to remove the striping. This water cannot be dumped along the road side and must be properly disposed of. This presents multiple problems. The downtime to send the contaminated water off for disposal and the cost of proper disposal. Also, these systems do not move very fast. They operate at approximately 7,000 ft per hour. 
   Therefore, what is needed in the art is a stripe removal system that is capable of efficiently removing striping and other markings without damage to the underlying surface. The system should remove the striping without damaging the underlying surface in the event that new striping is to be subsequently applied. Also, what is needed is a system which will not contaminate the environment by allowing abraded dust and particulate mater from the roadway to be released into the atmosphere or surroundings. In addition, the system should be capable of employing water to remove the striping efficiently without excessive disposal costs or downtime. Finally, the system should be capable of removing striping at surface speeds far in excess of those currently available. 
   SUMMARY OF THE INVENTION 
   Disclosed is a cleaning system for removing coatings from a surface by a combination of abrading and high pressure liquid. Striping and markings on roadways normally comprise paints or thermoplastics. These markings normally extend approximately ¼ inch above the surface and approximately ¼ inch below the surface. Surface removal of the striping and markings is not sufficient to completely remove them. The marking removal system of the instant invention employs a combination of an abrading device and high pressure liquid to remove the markings without damage to the underlying surface. The prior art devices have relied on high pressure liquids to remove the markings above and below the surface. One of the problems with these systems is that the rate of marking removal is very slow. The instant invention overcomes this problem by employing an abrading device to remove the markings above the surface and high pressure liquid to remove the markings below the surface. The abrading device removes the markings above the surface at a substantially greater rate than high pressure liquids can. This leaves the markings below the surface for the high pressure liquids to remove. Since the high pressure liquids only have to remove the markings below the surface they can accomplish this at a substantially greater rate than having to remove the markings both above and below the surface. As a result the instant invention can remove markings on a surface at a substantially greater rate than the prior art devices. 
   Accordingly, it is an objective of the instant invention to provide a marking removal system which employs both an abrading device and a high pressure liquid device to remove the markings. 
   It is a further objective of the instant invention to provide a marking removal system which permits rapid and efficient removal of markings at a substantially greater rate than prior art devices. 
   It is yet another objective of the instant invention to provide a marking removal system mounted on a single mobile vehicle which can operate at speeds substantially greater than prior art vehicles, up to approximately 25 MPH. 
   It is a still further objective of the invention to provide a marking removal system which operates a high pressure water pump, a vacuum pump, a hydraulic pump and an infinitely variable speed hydrostatic drive from a single prime mover. 
   Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein 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 FIGURES 
     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: 
       FIG. 1  is a side view, partially in section, of one embodiment of the instant invention with the blast head and abrasion means in the operational position; 
       FIG. 2  is a partial side view of the prime mover and the drive line of one embodiment of the instant invention; 
       FIG. 3  is a top view of the embodiment illustrated in  FIG. 1  illustrating the positions of the blast heads and abrading devices; 
       FIG. 4  is a side view of an embodiment of the invention with the blast head and abrading device in their operational positions. 
       FIG. 5  is a schematic illustration of the second transmission of the instant invention; 
       FIG. 6  is a perspective view of a spray or blast head and 
       FIG. 7  is a top sectional view of a abrading device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   While the present invention is susceptible of embodiment in various forms, there is shown in the accompanying drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. 
   The marking removal system  10 , shown in  FIG. 1 , includes a prime-mover vehicle  12 , preferably a truck, which has an elongated frame or chassis  14 . Mounted on a front portion of the elongated chassis  14  is a cab  16  for enclosing the operator as well as the driving and operating controls. Mounted on a front portion of the chassis is a prime mover  44  ( FIG. 2 ). The prime mover is generally an internal combustion engine of a type well known in the art, utilizing diesel, gasoline, propane, natural gas or other suitable fuels. 
   Referring to  FIG. 2 , the prime mover  44  is connected to the truck drive-train which includes a first transmission  46  and a second transmission  48  as well as the drive axle gears  50 . The first transmission is operatively coupled to the prime mover as is well known in the art. The first transmission is preferably a manual type transmission with multiple forward and reverse gears such as is well known in the art. Alternatively, an automatic transmission having at least one forward and one reverse gear may be utilized without departing from the scope of the invention. The first transmission includes a case  52  and an output shaft  54 . 
   The second transmission  48  is secured to the chassis of the truck between the output shaft of the first transmission  46  and the drive axle  50 . The second transmission includes a case  56 , a first input shaft  58 , a first output shaft  60 , a second output shaft  62 , a third output shaft  64 , a hydraulic pump output  66 , and a hydraulic motor input  68 . In the first preferred embodiment, the first input shaft  58  and the first output shaft  60  are axially aligned to extend from both sides of the case  56 . Also, within the preferred embodiment, the second and third output shafts  62 ,  64  are axially aligned to extend from both sides of the case  56  and are spaced above the first input and output shafts as illustrated in  FIG. 2 . Alternatively, the second and third output shafts  62 ,  64  may be parallel with respect to one another and spaced in a horizontal plane to be above or below the first input and output shafts respectively. The hydraulic pump output  66  and hydraulic motor input  68  are preferably positioned along the outer surface of the case  56  between the axis of the second and third outputs and axis of the first input and output. However, it should be noted that other positions suitable for mounting the hydraulic pump and motor may be utilized without departing from the scope of the invention. Transmissions such as the second transmission described above are available from suppliers such as Omsi Transmission of Volciano Italy and are disclosed in U.S. Pat. Nos. 5,826,460 and 6,393,944, the contents of which are incorporated herein by reference. 
   A first drive shaft  70  is connected to the output  54  of the first transmission  46  and the first input  58  of the second transmission  48 . A second drive shaft  72  is coupled between the output shaft  60  of the second transmission  48  and the drive axle  50  of the truck. 
   Referring to  FIGS. 1-4 , mounted on a rear portion  74  of the chassis is a holding tank  18 , including a water tank portion  20  and a vacuum recovery tank portion or sump  22 . In one embodiment the rear portion  24  of the holding tank is pivotally mounted on the truck chassis  14  and hydraulicly powered to tilt in the vertical plane to permit dumping of the contents of the vacuum recovery tank or sump. The recovery tank  22  is operably connected to a vacuum pump  26  by a suitably sized conduit  28 . The vacuum pump is preferably capable of drawing approximately 1100 CFM (cubic feet per minute) of air through the vacuum tank. Operably connected between the vacuum tank and the vacuum pump is a dust separator  30 . The dust separator is constructed and arranged to prevent airborne particles drawn through the vacuum tank from being drawn through the vacuum pump and discharged into the atmosphere. 
   Also mounted on the chassis is a high-pressure water pump  32 . The high-pressure water pump is capable of supplying 2-15 GPM (gallons per minute) of water to at least one spray head  34  at 25,000-45,000 PSI (pounds per square inch). In a most preferred embodiment, the high pressure water pump is constructed and arranged to deliver 6 GPM to each of the rotating spray heads at about 40,000 PSI. A high pressure hose or conduit is used to connect the high-pressure water pump with the spray head(s). A single spray head  34  may be mounted on one side of the truck as shown in  FIG. 1  or multiple spray heads may be mounted on one side of the truck as shown in  FIG. 3 . In addition, the spray heads  34  may be mounted on both sides of the truck to provide for a doubling of the treatment area at a given speed of the truck. 
   A spray head or blast head  34  will now be described with reference to  FIG. 6 . A plurality of high pressure nozzles (not shown) are rotatably secured within the spray head  34  along an elongated tubular member (not shown). Rotation of the elongated tubular member is controlled via a hydraulic motor  76 . Hydraulic pump  78  and/or  80  supply hydraulic fluid to the hydraulic motor  76  via high pressure hose  82  ( FIGS. 1 and 4 ). Hydraulic motor  76  is coupled to a rotary shaft (not shown) mounted in housing  108  and the elongated tubular members are mounted on the rotary shaft. By controlling the pressure and flow of the hydraulic fluid the speed of rotation of the tubular members can be controlled. A control device (not shown) is provided in the cab  16  of the truck to allow an operator to vary the speed of the rotating tubular members. The spray or blast head is carried on a chassis  84  supported on casters  86 . A shroud  88  descends from the chassis and surrounds the high pressure nozzles. The spray head is connected to the high pressure fluid pump by high pressure hose  90  and the shroud  88  is connected to the vacuum tank by a vacuum hose  92 . The spray or blast head has to remove only the markings below the surface of the road or area to be cleaned as a result of the abrading device, the operation of which will be explained below. Therefore the rate of removal of the markings is substantially increased and the rate that the truck can move down the road is substantially increased. 
   The abrading device  108  will now be described with reference to  FIG. 7 . A substantially rectangular housing  110  surrounds a pair of cylindrical grinders  112 . Each cylindrical grinder is mounted on a rotary axle  114  which is mounted by bearings or other suitable means (not shown) in side portions of the housing. A hydraulic motor  116  is connected to each rotary axle at one end thereof and drives the axle. The hydraulic motor  116  is connected to hydraulic pump  78  and/or  80  via high pressure hose  118  and controlled from the cab of the truck. A vacuum hose  120  connects the housing to a debris collection tank  122 . The markings and other debris removed by the abrading device are drawn into the debris collection tank via the vacuum pump  124 . Vacuum pump  124  is driven by hydraulic motor  125 . The debris is separated from the air in the debris collection tank. Operably connected between the outlet of the debris collection tank and the vacuum pump  124  is a dust separator  126 . The dust separator is constructed and arranged to prevent airborne particles from being drawn through the vacuum pump and discharged into the atmosphere. Vacuum pump  124  is similar in size and construction to vacuum pump  26 . While two cylindrical grinders are illustrated in a preferred embodiment, a single cylindrical grinder can also be employed in each abrading device  108 . Since the abrading device removes the markings above the surface of roadway, without having to remove the markings below the surface, the rate of removal is substantially increased and therefore the truck can move substantially faster down the road or surface to be cleaned. Alternatively, the abrading device does not have to be provided with a debris collection device. The debris can be collected by the collection device of the blast heads which follow behind the abrading device. 
   In an alternative embodiment, illustrated in  FIG. 4 , a single vacuum pump  26  is connected to both vacuum recover tank  22  and debris collection  122 . Dust separator  30  is operably connected between to both tanks via conduits  28  and  128  and the vacuum pump  26 . In this embodiment both manufacturing costs and equipment weight are saved through the use of a single vacuum pump and a single dust collector. 
   Referring to  FIG. 5 , a schematic representation of one embodiment of the second transmission  48  is illustrated. The construction of the second transmission  48  provides the marking removal truck with two modes of operation, a transport mode and a work mode. In the transport mode the first input shaft  58  of the second transmission is operatively coupled to the output shaft  60 . The engagement between the shafts may be accomplished utilizing splined shafts and a ring having internal splines or other suitable means for coupling the shafts. In the preferred embodiment a fluid powered cylinder  96  is utilized to slide a ring to engage the two shafts. Other means such as cables or levers may be utilized in place of the fluid cylinder without departing from the scope of the instant invention. This construction allows power from the prime mover  44  and the first transmission  46  to drive through the second transmission to the drive axle  50  of the truck for transport of the entire marking removal system in a conventional manner. 
   In the work mode, the input shaft  58  of the second transmission is uncoupled from the output shaft  60  via the fluid cylinder moving the engagement ring as described above. The second and/or third output shafts  62 ,  64  are coupled to the input shaft  58  via clutches  98  or other suitable means of engagement. Engagement of the second and/or third output shaft preferably engages the hydraulic pump output  66  to drive a first hydraulic pump  80 , most preferably a variable volume pump. The second output shaft  62  is operably connected to the high pressure water pump  32  via belts pulleys. Alternatively, gears, chain drives or suitable combinations thereof may be utilized to connect the second output shaft to the high pressure water pump. In one embodiment, the third output shaft  64  is operably connected to a second hydraulic pump  78  ( FIG. 1 ). The second hydraulic pump is fluidly connected to hydraulic motors  102  and  125  which are operably secured to the input shaft of vacuum pumps  26  and  124  respectively. 
   In an alternative embodiment, the third output shaft  64  is operably connected to the vacuum pump  26  via belts and pulleys as illustrated in  FIG. 4 . Alternatively, gears, chain drives or other suitable combinations thereof may be utilized to connect the third output shaft to the vacuum pump without departing from the scope of the instant invention. In this embodiment the second hydraulic pump  78  and hydraulic motor  102  are eliminated. 
   In the work mode the first hydraulic pump  80  and hydraulic motor  94  are utilized to form a mechanical-hydrostatic transmission, wherein fluid generated by the first pump  80  is delivered to the first hydraulic motor  94 . The hydraulic motor is coupled to the hydraulic motor output shaft of the second transmission by suitable means such as a slip ring with internal splines  104 , gears, clutches, chains or suitable combinations thereof. In the preferred embodiment a fluid powered cylinder  106  is utilized to slide the slip ring to engage the output shaft to the hydraulic motor. Other means such as cables or levers may be utilized in place of the fluid cylinder without departing from the scope of the invention. A joystick type control (not shown) is provided within the cab of the truck to allow an operator to infinitely control the speed of the truck within a predetermined range. In a most preferred embodiment the mechanical-hydrostatic transmission is constructed and arranged to propel the marking removal system from 0 to about 10 MPH. 
   The system described above is especially useful for marking removal on roadways or cleaning large surfaces, such as airport runways. The prime mover may be set at an optimum RPM for efficiency or power. The chassis mounted equipment is then powered from the prime mover thereby eliminating the need for additional prime movers for their operation. With the weight of the additional prime movers eliminated, the truck can carry additional water for extended operation without the need to refill the water tank  20 . The mechanical-hydrostatic transmission allows the speed of the truck to be controlled for optimum marking removal. For example, the ground speed of the truck may be increased between marks being removed, such as dashed lines, without changing the speed of the prime mover and affecting the operation of the high pressure liquid pumps, the blast head, the abrading device or the vacuum pumps. In addition, the increased horsepower provided by the prime mover, since it does not have to propel the truck, allows for increased water pump size when compared to the prior art devices. The increased water pump size facilitates increased removal rates and/or the ability to operate multiple spray or blast heads as illustrated herein. The additional horsepower allows for the hydraulic pumps to operate the abrading devices without affecting the operational efficiency of the spray or blast heads. In addition to removing markings, the system is useful for tasks such as removal of accumulated rubber from airport runways, cleaning parking lots, cleaning factory floor and the like. 
   All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. 
   It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein. 
   One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.