Abstract:
A padeye cleaning system includes a housing having an outlet designed to be positioned in communication with the opening in a padeye cover with a media inlet for introducing a pressurized media flow into the housing and through both the housing and the opening in the padeye cover for releasing a pressurized media flow into the padeye receptacle. A media exhaust port is provided for removing the released media flow from the receptacle.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The subject invention is generally related to media blasting systems and is specifically directed to a pressurized media delivery system for cleaning padeyes and similar open-topped, closed recesses or tie-downs. 
         [0003]    2. Discussion of the Prior Art 
         [0004]    Generally, a padeye is a recessed cleat or tie-down on the deck of a ship. Padeyes and other components for securing cargo or equipment to a ship are generally referred to as tie-downs, which generically includes padeyes. This invention is directed to padeyes and tie-downs substantially flush mounted on a surface and having a recess or cavity, sometimes referred to as a can, positioned beneath the surface. The terms padeye and tie-down are used interchangeably throughout this disclosure and refer to any unit which is substantially flush mounted on a surface with a recess beneath the surface. Such units are typically set flush with the surface of the deck or floor so that they do not create an obstruction to the surface when not in use. 
         [0005]    There are several types of padeyes currently in use. They are generally used to tie-down or secure cargo or equipment in place on the deck of the ship using lines which are secured at one end to the cargo and at the other end to the padeye. Several types of padeyes are shown and disclosed in the following U.S. Pat. Nos. 4,672,909; 5,004,388; 5,106,248; 5,301,627 and 5,535,694. All of theses padeyes have one thing in common. Each is housed in a can or receptacle which is recessed in the deck. Currently, one of the most common padeye has an inverted dome shaped receptacle mounted in the deck with a flat cover having a cross-opening or clover-leaf opening designed to engage a link of chain for securing the cargo to the ship deck. The center opening of the padeye is enlarged to permit the link to be removed for loosening or tightening the chain. Because of the location of the padeye or other tie-down in the deck of a ship, it is in a highly corrosive environment. This requires frequent cleaning of the padeye or tie-down, in particular of the receptacle which is recessed in the deck. The receptacle is prone to collect seawater, oil and other materials which may collect on the deck. 
         [0006]    The prior art cleaning methods included removing the padeye or tie-down for cleaning, or using a water or fluid blasting system for pressure washing. The liquids used were somewhat limited because of the need to protect the deck from corrosive materials. At best these systems are expensive and time consuming, and marginally effective. 
         [0007]    Typically, the water blasting system of the prior art would permit the cleaning of approximately two or three padeyes per hour. A typical U.S. Naval cargo ship may have several hundred padeyes on the top deck, meaning is would take one hundred or more hours just to clean the padeyes. Since the padeyes have to be cleaned regularly, this has become an almost full time job. In most fluid cleaning systems, the system was open-looped, permitting the fluid to run over the deck during the cleaning process. 
         [0008]    Also, since the open top member is generally welded to the receptacle, it is difficult to clean the entire padeye with just a liquid blast. The pressurized stream needs to flow directly from the nozzle to the surface being cleaned. Once a liquid stream hits a surface it dissipates rapidly and there is little or no rebound benefit. Basically, even if such systems were functional for cleaning that portion of the padeye receptacle they were of marginal effect when cleaning the underside of the cover or the junction between the top and the receptacle around the perimeter. 
         [0009]    Inability to provide thorough cleaning of padeyes or other tie-downs of this nature results in premature failure, requiring costly replacement. There is a need for a more efficient and more effective system for in situ cleaning of padeyes and the like. 
       SUMMARY OF THE INVENTION 
       [0010]    The subject invention is a closed loop system, wherein the cleaning material may be recycled and reused as the padeye is cleaned. It uses a solid, particulate media cleaning agent which is propelled under pressure air to drive the media into the surface of the padeye for abrasively removing corrosion and dirt. In its preferred form the cleaning system of the subject invention includes a housing with an open bottom which may be placed over the padeye. An input conduit or tube is selectively extendable through the housing and into the padeye receptacle. The lower end of the tube is coupled to a nozzle assembly having one or more nozzles. The tube extends above the housing and is rotatable to direct each nozzle to various points in the receptacle. The nozzles may be angled to direct the propelled media to different locations in the receptacle. 
         [0011]    Where desired, the tube and nozzles may be selectively positioned above the padeye for cleaning the surface area surrounding the padeye. 
         [0012]    In the preferred embodiment, the invention comprises a base housing having a housing outlet designed to be positioned in communication with the opening in a padeye. A media inlet tube or conduit extends through the housing for introducing a pressurized media flow into the base housing and/or through the housing and the opening in the padeye and into the padeye recess. A media outlet nozzle assembly releases a directed pressurized media flow into the area surrounding the padeye or into the padeye recess, as desired. A media exhaust port is provided for removing the released media flow from the padeye surface, padeye recess and the base housing. The system may be a closed loop with the recaptured, exhausted released media reintroduced into the media inlet conduit, or may be a vacuum sealed open circuit with the recaptured media being stored or disposed of, or a combination thereof. 
         [0013]    In the preferred form the padeye cleaning system is mounted on a wheeled carriage or dolly for supporting the base housing, supply conduit and nozzles. This makes the system easy to maneuver with little or no disassembly required as the system is moved from work station to work station. 
         [0014]    The use of a solid particulate matter provides several advantages over the prior art. First, it can be applied at a lower pressure than the liquid systems. Pressurized water, for example, must be propelled at a pressure of greater than  1400  psi to be effective. The solid particulate media can be propelled under a pressure of around  70  psi or more with better results. 
         [0015]    In addition, the solid particulate media stays intact after impact, providing rebound cleaning as it bounces around in the receptacle. This assures better cleaning of hard to reach places, especially around the upper perimeter at the junction between the top of the can or receptacle and the bottom wall of the padeye top member. 
         [0016]    In the preferred embodiment of the invention a plurality of nozzle configurations may be used. A first configuration points slightly downward to assure cleaning of the base of the receptacle. A second configuration is substantially horizontal for general cleaning. A third configuration points slightly upward to clean the perimeter of the top of the receptacle and to clean the underside of the padeye cover. 
         [0017]    Where desired, a nozzle configuration placing the conduit above the padeye the nozzle outlet above the padeye cover may be used to clean the exposed, upper surface of the padeye cover, and the surrounding deck surface where desired. 
         [0018]    In the preferred embodiment of the invention the housing is wheeled to facilitate movement of the housing from padeye to padeye along the deck of a ship. 
         [0019]    Using this system, each padeye generally takes approximately ten to fifteen minutes to fully clean, permitting cleaning of up to six padeyes in an hour, versus two when using prior art systems. In addition, when using either the closed loop system or the captured exhaust system, there is only a minimum of clean-up after each padeye is completed. This is in contrast with liquid systems which almost always release the cleaning liquid to the deck. In addition, water blasting requires rust inhibiting additives so only rust inhibitive compatible paint can be used on the surfaces being cleaned. The water has to dry before re-painting can begin and protective gear is required to worn by the operator. The system of the present invention eliminates these issues. 
         [0020]    The closed loop and/or recovery system of the subject invention is also desirable over the open systems of the prior art because it minimizes any environmental hazard. Basically, the padeye cleaning system of the present invention provides a safer, cleaner, faster and less expensive system for cleaning recessed padeyes on a ship deck. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a side view of a padeye cleaning system in accordance with the subject invention, with the nozzle assembly in the lower, recess cleaning position. 
           [0022]      FIG. 2  is a partial section rotated 90 degrees from  FIG. 1 , with carriage removed for clarity and showing the input tube and base housing assembly. 
           [0023]      FIG. 3  is an enlarged partial section view looking in the same direction as  FIG. 1 . 
           [0024]      FIG. 4  is an enlarged partial section view looking in the same direction as  FIG. 2 . 
           [0025]      FIG. 5  is a further enlarged partial section view looking in the same direction as  FIGS. 4  and showing the blast wand and lifting tube interface. 
           [0026]      FIGS. 6A ,  6 B and  6 C are partial views showing the positions of the nozzle assembly in the center of the padeye ( FIG. 6A ), the nozzle assembly above the padeye for surface cleaning ( FIG. 6B ) and the nozzle assembly in the recess of the padeye ( FIG. 6C ). 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    A basic configuration of the padeye cleaning system of the subject invention is shown in  FIG. 1 , designated by the reference numeral  10 . It is designed to be seated over a typical padeye  12  which is flush mounted in the deck  14  of a ship. The padeye includes a receptacle or can  16  and an open top  18 . 
         [0028]    In the preferred embodiment the system is mounted on a wheeled dolly  20  for portability and maneuverability. As shown in  FIG. 1 , wheels  22  allow the operator to quickly move from one tie down to another. The operator can use the handle  25  on the skid dolly to pull the containment system back so that it rest upon the wheels  22  and may be rolled to the desired location. The basic components of the containment system are the base  11 , supply tube  26 , and the nozzle assembly  27 . 
         [0029]    The control box  24  houses the indicator lights for blast air ON, grit flow ON, and vacuum sensed inside base chamber. The control system for the padeye cleaning system operates in typical manner as is well-known in the industry and provides controls for initiating and terminating flow through the inlet tube  26  via the flexible blast hose  28  and the connector  30 . Typically the control box  24  includes a three position switch for system OFF, grit blasting (compressed air and grit ON), or compressed air only, AIR, (no grit). The compressed air only mode is used to help purge the tie down and base chamber of residual grit and trash. 
         [0030]    Below is the control box on the dolly is the vacuum switch  32  which disables the system until sufficient vacuum is sensed inside the base chamber  34 , see  FIG. 2 . This feature is for assurance of containment and personnel safety. The vacuum connector port  66  is in communication with the base cavity  34 . 
         [0031]    The blast hose  28  terminates at one end at a swivel coupling  36 , and at the other end at the coupling  30  which is used to connect the system to a blast pot (not shown) which properly mixes the grit and compressed air and conveys it to the angled blast nozzles in the nozzle assembly  27 . The flexible blast hose permits vertical adjustment of the inlet tube  26  and the nozzle assembly  27 . The inherent curve  38  of the blast hose at this location is an accelerated wear point. By providing the short modular section of hose  28  the end user will only have to replace a small length of hose instead of the entire supply hose from the blast pot to the input tube coupler  36 . 
         [0032]    The wheel  40  is provided for rotating the nozzle inlet tube  26  and nozzle assembly  27  during operation. 
         [0033]      FIG. 2  is a partial cross-section of the system, with the wheeled dolly removed, for clarity. At top is the blast hose  28  which carries the compressed air and abrasive grit mixture and introduces it into the inlet tube  26 . The blast hose swivel coupling ties into the top of the hose swivel and the bottom connection has pipe thread or other connection that is connected to the inlet tube  26  (or blast wand). Below the hose swivel is the manual wheel  40  for rotating the tube  26  and nozzle assembly  27 . 
         [0034]      FIG. 3  (a partial section view looking in the same direction as  FIG. 1 ) and  FIG. 4  (a partial section view looking in the same direction as  FIG. 2 ) are enlarged for clarity. The inlet tube or blast wand  26  and the nozzle assembly  27  are mounted for vertical and rotational movement in the base  11 . The blast wand is located concentrically inside a lift tube  50  and a hollow threaded rod  52 . A base plate  54  is rigidly attached to the bottom end  56  of the hollow threaded rod  52 . This plate is fastened onto the base flange  58  with three quick release fasteners  60  (two shown in  FIG. 3  and one shown in  FIG. 4 ). The quick release fasteners are required to allow quick removal of the threaded rod flange to access the blast nozzle assembly  27  ( FIG. 2 ) to switch from external blasting nozzles to internal blasting nozzles or vice versa. 
         [0035]    Between the threaded rod plate  54  and the base flange  58  is a gasket  62  to seal the blasting chamber  34  inside the base  11 . Below the base flange  58  and located on the base  11  is an atmospheric vacuum intake port  36  ( FIGS. 2 and 4 ) which allows air flow from ambient into the blast chamber and keep air flowing through the vacuum reclaim system. This port is sized such to allow continuous vacuum flow and still produce sufficient vacuum inside the base chamber to produce sufficient downward sealing force upon the base seal  64  ( FIGS. 1 and 2 ) against the deck  14 . Below the atmospheric vacuum intake port  64  is the vacuum switch port  36  which is hosed to the vacuum switch  32  ( FIG. 1 ). This vacuum switch will not allow blasting if sufficient vacuum is not sensed inside the base chamber  34 . This helps to ensure that blasting cannot be performed until the base  11  is sealed against the deck  14  and the operator cannot inadvertently turn on the blast operation while moving from one tie down to another. 
         [0036]    A clean out port  68  is provided for purging the system and cleaning out the blast chamber  34  during blast and purge operations. The clean out port is connected to a vacuum system (not shown) for reclamation, screening and reusing the abrasive. 
         [0037]    In the preferred embodiment of the invention the inlet tube (blast wand)  26  and nozzle assembly  27  are mounted in the lift tube  50  for rotation and vertical adjustment relative to the base  11 . As shown, the fixed threaded rod  52  is mounted on the base plate  58  which is removably secured to the base  11  by the disconnects  60 . In the exemplary embodiment a threaded receptacle such as, by way of example, the nut  70 , is provided in or on the base plate  54 . The threaded rod  52  is then secured in the receptacle  70 . This prevents dirt and grit from accumulating in these gaps. 
         [0038]    A similarly threaded receptacle or nut  72  is secured to the lower end  74  of the lift tube  50 . Handles  76  are mounted in the lift tube  50  to facilitate rotation and vertical adjustment of the lift tube relative to the threaded rod  52  and to the base  11 . In the embodiment shown the handles  76  are hollow pipes or tubes open to the interior of the lift tube. These function as a fresh air intake to continuously purge the gap between the internal diameter of the threaded rod  52  and the outer diameter of the blast wand  26 , see opening at  78 . 
         [0039]    As best seen in  FIGS. 4 and 5 , the upper end  80  is capped with a cap  82  which is rigidly secured to the lift tube  50 . The cap has a central aperture  84  for accommodating the blast wand  26 . The blast wand has a flange  86  positioned above the cap  82 . A resilient washer  88  is placed between the flange  86  and the cap  82 . This assembly permits the blast wand to rise and fall with the lift tube  50 , while at the same time permitting rotation of the blast wand relative to the lift tube and the base, permitting both rotation and vertical adjustment of the nozzle assembly  27 . 
         [0040]    As also best shown in  FIG. 5 , the turn wheel  40  is secured directly to the blast wand  26  at hub  90 . This permits the nozzle assembly  27  to be rotated relative to the blast base  11  for selectively positioning and rotating the nozzles during operation. It should be understood that the selection of the rotation wheel is arbitrary and other devices and assemblies for rotation could be readily employed without departing from the invention. 
         [0041]    The nozzle positions during operation are illustrated in  FIGS. 6A ,  6 B and  6 C.  FIG. 3A  shows the blast nozzle  27  at the center of a cloverleaf padeye  18 . As shown in  FIGS. 3B and 3C  angled orifice nozzles  100  and  102  are secured to the lower end of the blast wand  26 . Rotating the angled orifice nozzles one or more revolution will blast clean a donut shape area. The nozzles may be angled as a matter of choice depending on the operation. In  FIG. 6B  the nozzles are positioned for higher and lower external cleaning. In  FIG. 6C  the nozzles are positioned in the higher and lower recess or receptacle cleaning positions. 
         [0042]    Where desired, the wheel  25  may include indexing marks  110 ,  112  on its perimeter to show the position of the nozzles during rotation. This permits non-visual systematic geometric blast coverage by providing an external indication of each nozzle position during rotation. As shown in  FIGS. 1 and 2 , calibration marks  114  may be provided on the tube to show the vertical position of the nozzles without visual access to the nozzles. 
         [0043]    While certain features and embodiments of the invention have been described in detail herein, it should be understood that the invention includes all modifications and enhancements within the scope and spirit of the following claims.