Abstract:
Briefly, disclosed is an ultra high pressure blasting head for a mobile marking removal system. The blasting head includes a hydraulic motor that is constructed and arranged for direct connection to a spray bar for controlled rotation thereof. The output shaft of the hydraulic motor is constructed to be hollow or tubular so that the ultra high pressure water can be supplied to the spray bar through the output shaft. The spray head assembly is particularly suited for mobile systems utilized to remove markings and/or coatings from surfaces with high or ultra high pressure liquid.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application No. 61/032,286, filed Feb. 28, 2008, entitled “WATER BLASTING HEAD WITH THROUGH FEEDING HYDRAULIC MOTOR”, the entirety of which is incorporated herein by reference. This application is also related to U.S. Pat. No. 7,255,116, entitled “STRIPE REMOVAL SYSTEM”; U.S. patent application Ser. No. 11/340,738, filed Jan. 26, 2006, and entitled “TRANSPORTAL HOLDING TANK FOR STRIPE REMOVAL SYSTEM”; U.S. patent application Ser. No. 11/340,104, filed Jan. 26, 2006, entitled “MOBILE MARK REMOVAL SYSTEM”; U.S. patent application Ser. No. 11/368,020, filed Mar. 3, 2006, entitled “ARTICUABLE ARM FOR A MOBILE MARK REMOVAL SYSTEM”; U.S. patent application Ser. No. 11/368,035, filed Mar. 3, 2006, entitled “COMBINED GRINDER AND WATER BLASTER FOR STRIPE REMOVAL”; and U.S. patent application Ser. No. 11/835,642, filed Aug. 8, 2007, entitled “STRIPE REMOVAL SYSTEM”. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to the field of high pressure water cleaning devices for highways, runways, parking decks, factory floors and other marked surfaces. More specifically the invention is a high pressure water blasting head that includes a through feeding hydraulic motor for supplying the spray bar of the blast head with ultra high pressure water. 
       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 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. 
         [0004]    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. 
         [0005]    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. 
         [0006]    It is also known in the art of marking removal to utilize high pressure water to remove road markings and the like. For example, U.S. Pat. No. 5,078,161 to Raghaven et al. discloses a method of cleaning an airport runway utilizing ultra high pressure water. The device disclosed by Raghaven includes a rotatably mounted spray bar. A hollow conduit extends to the spray bar through which the high pressure water is supplied to the spray bar. A hydraulic motor and belt are utilized to rotate the hollow conduit and the spray bar simultaneously. A drawback to this configuration is component failure and wasted energy. Belts or chains are prone to breakage and require additional maintenance. The use of a gear train between the motor ant the conduit requires precision mounting points for alignment significantly increasing the cost of the assembly. 
         [0007]    Therefore, what is needed in the art is a high pressure water blasting head having a hydraulic motor with a tubular output shaft. The tubular output shaft should be constructed and arranged to directly rotate at least one device, preferably a spray bar, with a first pressurized fluid while allowing the passage of a second fluid through the pump via the output shaft to supply the second fluid to the rotated device. 
       SUMMARY OF THE PRESENT INVENTION 
       [0008]    Briefly, disclosed is an ultra high pressure blasting head for a mobile marking removal system. The blasting head includes a hydraulic motor that is constructed and arranged for direct connection to a spray bar for controlled rotation thereof. The output shaft of the hydraulic motor is constructed to be hollow or tubular so that the ultra high pressure water can be supplied to the spray bar through the output shaft. The spray head assembly is particularly suited for mobile systems utilized to remove markings and/or coatings from surfaces with high or ultra high pressure liquid. The mobile system generally employs a liquid reservoir connected to a high or ultra high pressure pump for directing ultra high pressure water through the output shaft of the motor to the blast head mounted on a front portion of a vehicle. A vacuum reservoir and vacuum pump are preferably utilized to recover the water and debris from the surface. The arm permits an operator to easily maintain alignment of the blast heads to the surface markings being removed. After marking removal, the arm permits the blast head(s) to be raised to a position suitable for vehicle transport. 
         [0009]    Therefore, it is an objective of this invention to provide a blast head assembly for a mark removal system. 
         [0010]    It is another objective of the instant invention to provide a blast head assembly wherein a rotating spray bar connects directly to the output shaft of a hydraulic motor. 
         [0011]    It is a further objective of the instant invention to provide a hydraulic motor for a blast head assembly wherein the hydraulic motor is provided with a hollow or tubular output shaft for supplying high pressure fluid to the spray bar. 
         [0012]    It is yet a further objective of the instant invention to provide a hydraulic motor with a hollow or tubular output shaft for supplying a secondary fluid to the device or assembly being rotated by the motor. 
         [0013]    It is still another objective of the instant invention to provide a blast head assembly having a spray bar rotatable by a hydraulic motor with a tubular output shaft so that high pressure water can be supplied to the spray bar through the output shaft of the hydraulic motor. 
         [0014]    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 
         [0015]    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: 
           [0016]      FIG. 1  is an exploded perspective views of one embodiment of the instant invention; 
           [0017]      FIG. 2A  is side view of one embodiment of the blast head of the instant invention illustrated with a caster plate for mounting one or two blast heads; 
           [0018]      FIG. 2B  is section view of one embodiment of the instant invention; 
           [0019]      FIG. 2C  is a partial section view illustrating the thrust assembly portion of the hydraulic motor assembly; 
           [0020]      FIG. 3  is a front view illustrating one embodiment of the instant invention; 
           [0021]      FIG. 4  is a partial side view illustrating one embodiment of the instant invention; 
           [0022]      FIG. 5A  is a front view of one embodiment of the hydraulic motor output shaft; 
           [0023]      FIG. 5B  is an end view of one embodiment of the hydraulic motor output shaft; 
           [0024]      FIG. 6  is a side view of one embodiment of the instant invention illustrated without the actuators for clarity; 
           [0025]      FIG. 7  is a section view of the output shaft embodiment illustrated in  FIGS. 5 and 6 ; 
           [0026]      FIG. 8  is a perspective view of one embodiment of the hydraulic motor output shaft; 
           [0027]      FIG. 9A  is a front view of one embodiment of the swivel inlet of the instant invention; 
           [0028]      FIG. 9B  is an end view of one embodiment of the swivel inlet of the instant invention; 
           [0029]      FIG. 10  is a section view of one embodiment of the swivel inlet of the instant invention; 
           [0030]      FIG. 11  is a side view of one embodiment of the swivel inlet of the instant invention; 
           [0031]      FIG. 12  is an end view of one embodiment of the swivel inlet of the instant invention; 
           [0032]      FIG. 13  is a perspective view of one embodiment of the swivel inlet of the instant invention; 
           [0033]      FIG. 14  is a top view of one embodiment of the flange adapter of the instant invention; 
           [0034]      FIG. 15  is a bottom view of one embodiment of the flange adapter of the instant invention; 
           [0035]      FIG. 16  is a perspective view of one embodiment of the flange adapter of the instant invention; 
           [0036]      FIG. 17  is a front view of one embodiment of the flange adapter of the instant invention; 
           [0037]      FIG. 18  is a right side view of one embodiment of the flange adapter of the instant invention; 
           [0038]      FIG. 19  is a section view of one embodiment of the flange adapter of the instant invention taken along lines B-B of  FIG. 17 ; 
           [0039]      FIG. 20  is a section view of one embodiment of the flange adapter of the instant invention taken along lines C-C of  FIG. 18 ; 
           [0040]      FIG. 21  is a top view of one embodiment of the thrust housing of the instant invention; 
           [0041]      FIG. 22  is a bottom view of one embodiment of the thrust housing of the instant invention; 
           [0042]      FIG. 23  is a perspective view of one embodiment of the thrust housing of the instant invention; 
           [0043]      FIG. 24  is a front view of one embodiment of the thrust housing of the instant invention; 
           [0044]      FIG. 25  is a right side view of one embodiment of the thrust housing of the instant invention; 
           [0045]      FIG. 26  is a section view of one embodiment of the thrust housing taken along lines D-D of  FIG. 25 ; 
           [0046]      FIG. 27  is a section view of one embodiment of the thrust housing taken along lines E-E of  FIG. 24 ; 
           [0047]      FIG. 28  is a section view of one embodiment of the thrust housing taken along lines N-N of  FIG. 25 ; 
           [0048]      FIG. 29  is a top view of the housing thrust cover of the instant invention; 
           [0049]      FIG. 30  is a perspective view of the housing thrust cover of the instant invention; 
           [0050]      FIG. 31  is a front view of the housing thrust cover of the instant invention; 
           [0051]      FIG. 32  is a right side view of the housing thrust cover of the instant invention; 
           [0052]      FIG. 33  is a section view of the housing thrust cover of the instant invention taken along lines G-G of  FIG. 32 ; 
           [0053]      FIG. 34  is a section view of the housing thrust cover of the instant invention taken along lines F-F of  FIG. 31 ; 
           [0054]      FIG. 35  is a bottom view of the housing thrust cover of the instant invention; 
           [0055]      FIG. 36  is a top view of the dirt shield of the instant invention; 
           [0056]      FIG. 37  is a perspective view of the dirt shield of the instant invention; 
           [0057]      FIG. 38  is a front view of the dirt shield of the instant invention; 
           [0058]      FIG. 39  is a right side view of the dirt shield of the instant invention; 
           [0059]      FIG. 40  is a section view of the dirt shield of the instant invention taken along lines H-H of  FIG. 39 ; 
           [0060]      FIG. 41  is a top view of the gland nut of the instant invention; 
           [0061]      FIG. 42  is a perspective view of the gland nut of the instant invention; 
           [0062]      FIG. 43  is a front view of the gland nut of the instant invention; 
           [0063]      FIG. 44  is a right side view of the gland nut of the instant invention; 
           [0064]      FIG. 45  is a section view of the gland nut of the instant invention taken along lines K-K of  FIG. 44 ; 
           [0065]      FIG. 46  is a bottom view of the gland nut of the instant invention; 
           [0066]      FIG. 47  is a top view of the grease seal nut of the instant invention; 
           [0067]      FIG. 48  is a perspective view of the grease seal nut of the instant invention; 
           [0068]      FIG. 49  is a front view of the grease seal nut of the instant invention; 
           [0069]      FIG. 50  is a section view of the grease seal nut of the instant invention taken along lines M-M of  FIG. 49 ; 
           [0070]      FIG. 51  is a top view of the counter washer of the instant invention; 
           [0071]      FIG. 52  is a perspective view of the counter washer of the instant invention; 
           [0072]      FIG. 53  is a front view of the counter washer of the instant invention; 
           [0073]      FIG. 54  is a side view of the counter washer of the instant invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0074]    Referring generally to  FIGS. 1-4 , a blast head  100  for use in removing markings from a marked surface is illustrated. The blast head  100  is constructed and arranged to be connected to a mobile vehicle, preferably at the front portion thereof at the distal end of a articulable arm (not shown) where it can be infinitely maneuvered to extend across the front portion and beyond the sides of the vehicle if desired. A joystick or other suitable control device (not shown) is provided in the mobile vehicle to allow an operator to manipulate the articulable arm about various axes for an operator determined path of the blast head(s). The mobile marking removal vehicle is preferably a truck however, tractors, heavy equipment and the like may be utilized without departing from the scope of the invention. 
         [0075]    In general the blast head  100  includes a mobile support structure in the form of a caster plate  14 . The caster plate is preferably constructed of a lightweight metal such as aluminum and includes a plurality of caster wheels for supporting the blast head at a predetermined distance from the surface being cleaned. A hydraulic motor assembly  200  is secured to an upper or lower surface of the caster plate for imparting selective rotation to a spray bar  24 . The hydraulic motor is provided with a hollow output shaft  8  for transfer of ultra high pressure water (e.g. 25,000-40,000 psi) through the pump to the spray bar  24 . In the preferred embodiment, the spray bar  24  is directly connected to the output shaft and includes an internal flow path  104  for the ultra high pressure water, a plurality of nozzle apertures  107  and a plurality of nozzles  106 . ( FIG. 4 ). Each of the nozzles having apertures therein for expelling the ultra high pressure water against a surface. In a most preferred embodiment the nozzle apertures are between 0.005 and 0.075 inches in diameter and a single spray bar may include nozzles with various diameter apertures. A shroud  15  is also secured to a bottom surface of the caster plate, preferably in contact with an adapter flange portion  4  of the hydraulic motor assembly  200  to enclose the spray bar assembly  24  for containment of debris and water deflected from the cleaned surface. The shroud  15  may also be provided with a vacuum aperture  102  for connection to a vacuum tank for collection of the debris and used water. It should be noted that multiple blast heads may be secured to the caster plate to create various arrays of blast heads for cleaning surfaces. 
         [0076]      FIG. 4  illustrates a partial view of the blast head  100  having the shroud  15  and caster plate  14  removed. The hydraulic motor assembly  200  of the instant invention includes a thrust assembly portion  108 , a motor block portion  110 , and a flange adapter portion  112 . The thrust assembly portion  108  is constructed and arranged to control the vertical thrust caused by expelling the ultra high pressure water out of the nozzles and against a surface. ( FIGS. 21-28 ). The thrust assembly includes a body portion  118 , at least one bearing  18  and at least one thrust washer  28 . Positioned juxtaposed to the thrust washer is a grease seal  12  threadably connected to the output shaft  8 . The grease seal preferably includes at least one O-ring  31  or other suitable seal for retaining grease in the area of the bearing  18  and the thrust washer  28 . Also contained within the thrust assembly body  118  is the counter washer  13 . ( FIGS. 51-54 ). The counter washer includes at least one and preferably two upstanding wall portions  114  and a centrally located aperture  116 . The central aperture is sized to cooperate with the output shaft for rotation therewith, while the upstanding wall portions cooperate with a proximity switch  30  for counting revolutions of the output shaft  8 . Secured to an upper portion of the thrust assembly body  118  is the thrust assembly cover  6 . The thrust assembly cover  6  is constructed and arranged to cooperate with the gland nut  10  which maintains position and prevents thrust separation between the output shaft swivel  9  and the output shaft  8 . Preferably a seal is provided between the gland nut  10  and the thrust assembly cover  6 . A second seal is also provided between the swivel and the thrust assembly cover to prevent dirt and the like from entering the thrust assembly  108 . 
         [0077]    Referring to  FIGS. 1-4 , the motor block portion  110  is generally constructed and arranged to rotate the output shaft when pressurized hydraulic fluid is directed thereto. The motor body  1  includes a cavity  120  sized and shaped for containing a driving surface that is subject to a pressure differential to cause rotation. In a most preferred embodiment, the motor block portion includes a gear arrangement as is typically utilized in external gear pumps and motors having a driving gear  114  and an idler gear  116 . The driving surface, e.g. gear, may be integrally formed to the output shaft or alternatively may be keyed clamped or otherwise secured thereto. It should also be noted that other types of motor configurations suitable for rotating the spray bar which could incorporate a hollow output shaft could be utilized without departing from the scope of the invention. Such motors may include, but should not be limited to positive displacement motors such as, direct drive gerotor, Orbiting gerotor, roller vane gerotor, vane motors, swash plate motors and the like. 
         [0078]    The flange adapter portion  4  is constructed and arranged to provide horizontal and vertical thrust support while also providing a mounting surface for securing the motor to the shroud  15  and/or caster plate  14 . The flange adapter includes at least bearing  26  secured in place with press fit and/or a retaining ring  27 . The bearing is sized to accept and support the outer diameter of the output shaft  8 . An upper flange  122  is provided for securing the flange adapter  4  to the motor assembly  200  while a lower flange  124  is provided to secure the motor assembly to the shroud and/or caster plate  14 . The flange adapter may also include weep holes  126  and the like well known in the art for allowing water to escape from the flange prior to entering the motor assembly. 
         [0079]    Referring to  FIGS. 5-16 , the output shaft  8  and swivel nozzle  9  are illustrated. The output shaft is preferably constructed from a durable material such as steel to include a hollow or tubular central bore  128 . As disclosed above the purpose of the central bore is to allow the passage of high or ultra high pressure liquid (water) to pass through the output shaft to the spray bar  24 . The ends of the output shaft are preferably provided with threads for securement to the thrust assembly as well as the spray bar. It should be noted that other means of securing the spray bar to the output shaft and the thrust assembly may be utilized without departing from the scope of the invention. Such means of securing may include, but should not be limited to, locking tapers, snap rings, spring pins, clamps, suitable combinations thereof, and the like. The upper portion  130  of the output shaft  8  includes a cavity  132  for accepting the swivel  9 . The bottom of the cavity  132  preferably includes a tapered seat  134  which cooperates with a tapered end  136  of the swivel. In a most preferred embodiment, the clearance between the side wall bearing surfaces  138  of the swivel is such that the ultra high pressure water passing between the swivel aperture  140  and the output shaft bore  128  provides lubrication between the two components without allowing substantial leakage. The bearing surfaces may also include grooves  142  which further allow the water to provide lubricity. A flange  144  is also provided on the swivel to cooperate with an inner surface  146  of the gland nut  10 . An upper tip portion  148  of the swivel extends through aperture  150  of the gland nut for connection to the high or ultra high pressure water pump (not shown). The gland nut  10  may also be provided with weep holes  152  to allow the escapement of excess water. 
         [0080]    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. 
         [0081]    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. 
         [0082]    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.