Abstract:
An abrasive media containment bag ( 11 ) having a bag portion ( 13 ), a nozzle fitting ( 15 ), a blast fitting ( 17 ), and a filter member ( 19 ) is disclosed. The abrasive media containment bag ( 11 ) allows the surface of an aircraft or aircraft component to be prepared for bonding by using abrasive blasting, without fear of contaminating other aircraft components with the abrasive media. The abrasive media containment bag ( 11 ) isolates the area to be treated ande recovers and contains the abrasive media.

Description:
This application claims benefit of provisional appln, 60/330,344 filed Oct. 18, 2001. 
    
    
     TECHNICAL FIELD 
     The present invention relates to abrasive blasting. In particular, the present invention relates to apparatuses for the recovery and containment of the abrasive media. 
     DESCRIPTION OF THE PRIOR ART 
     Click studs and other types of fasteners are bonded to the surfaces of aircraft and aircraft components to secure and hold electrical lines, hydraulic lines, and other items in desired locations. If these fasteners become loose, the items they are securing can rub together, against the surface of the aircraft, or against other aircraft components causing significant damage to the item, the aircraft, and/or other aircraft components. The failure of the bond between the fastener and the aircraft can lead to damage and destruction of critical aircraft components, resulting in dangerous flying conditions. Therefore, it is imperative that the bonds between these fasteners and the aircraft are prepared and formed as good as possible. 
     The current method of preparing the surface of the aircraft for bonding of click studs and other fasteners is hand sanding. Although it is known that abrasive blasting would provide a better surface treatment and preparation, abrasive blasting has been avoided for fear that the abrasive media would contaminate other components on the aircraft, as vacuum containment means are not always available or practical in confined spaces or on aircraft in the field. 
     SUMMARY OF THE INVENTION 
     There is a need for an improved method and apparatus for treating and preparing the surfaces of aircraft and aircraft components prior to bonding click studs and other fasteners to the aircraft or aircraft components. 
     Therefore, it is an object of the present invention to provide an improved method and apparatus for treating and preparing the surfaces of aircraft and aircraft components prior to bonding click studs and other fasteners to the aircraft or aircraft components. 
     The above objects are achieved by providing an abrasive media containment bag having a bag portion, a nozzle fitting, a blast fitting, and a filter member. The abrasive media containment bag according to the present invention allows the surface of the aircraft or aircraft component to be prepared for bonding by using abrasive blasting, without fear of contaminating other aircraft components with the abrasive media. The abrasive media containment bag isolates the area to be treated and recovers and contains the abrasive media. 
     The abrasive media containment bag according to the present invention provides significant advantages, including: (1) abrasive blasting can be used to treat and prepare the surface of the aircraft or aircraft component without fear of contaminating other aircraft components with the abrasive media; (2) the containment bag isolates the area to be treated; (3) the containment bag and be quickly and easily installed before use, and removed after use; (4) as a result of using the method of the present invention, the bonds are up to 30% stronger than bonds that were prepared by hand sanding; (5) 99.5% of the abrasive media can be recovered and contained; (6) the manufacturing costs are very low; and (7) the containment bag and the collected abrasive media can be quickly and easily disposed of. Some of the materials removed by the abrasive media, such as paint and primer, are designated as hazardous materials. By utilizing the present invention, these materials can be contained and disposed of properly with the abrasive media. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. However, the invention itself, as well as, a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a front perspective view of an abrasive media containment bag according to the present invention; 
         FIG. 2  is a rear perspective view of the abrasive media containment bag of  FIG. 1 ; 
         FIG. 3  is a side view in partial cross-section of the abrasive media containment bag of  FIGS. 1 and 2  shown in an aircraft surface preparation application; and 
         FIG. 4  is a perspective view of the abrasive media containment bag according to the present invention shown in a three-dimensional application. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-3  in the drawings, an abrasive media containment bag  11  according to the present invention is illustrated. Containment bag  11  may be used in a wide variety of applications to isolate surfaces to be treated, and recover and contain abrasive media from abrasive blasting operations. Although the present invention is described herein with respect to an abrasive blasting procedure to treat and prepare aircraft surfaces and aircraft components for bonding with click studs and other fasteners and components, it should be understood that the present invention may be used in any abrasive blasting procedure in which it would be desirable to isolate the surface to be treated, and recover and contain the abrasive media. Containment bag  11  includes a bag portion  13 , a nozzle fitting  15 , a blast fitting  17 , and a filter member  19 . 
     Bag portion  13  is preferably made from flexible clear, semi-clear, or otherwise translucent, plastic having a thickness in a range of about 0.003 to 0.006 inches, such as poly-2 film about 0.004 inches thick. When used in an application of abrasive blasting to treat and prepare aircraft surfaces and aircraft components for bonding with click studs and other fasteners, it is preferred that bag portion  13  be about 8.0 inches long and about 7.0 inches wide; however, it will be appreciated that the size and shape of containment bag  11  may varied widely depending upon the application in which the invention is used. For example, if a large surface area or part is being treated, bag portion  13  may be considerably larger. It is also preferred that bag portion  13  form a seamless enclosure; however, bag portion  13  may include seams, such as seams  21   a ,  21   b ,  21   c , and  21   d . If bag portion includes seams  21   a ,  21   b ,  21   c , and  21   d , it is preferred that seams  21   a ,  21   b ,  21   c , and  21   d  be sealed by bonding, heat-sealing, gluing, sewing, or other appropriate means, provided that seams  21   a ,  21   b ,  21   c , and  21   d  prevent the chosen abrasive media  31  from escaping bag portion  13 . In the preferred application, abrasive media  31  is 220 grit aluminum oxide. 
     Nozzle fitting  15  is a reinforced portion of bag portion  13 , and is preferably centrally located on the front surface of bag portion  13 . Nozzle fitting  15  may be integral with bag portion  13 , or may be a separate member that is connected to bag portion  13 . In cases where nozzle fitting  15  is a separate member connected to bag portion  13 , it is preferred that nozzle fitting  15  be made of rubberized abrasive masking tape, such as the tape sold by the Anchor company as model BT100, 3M 500 stripping tape, or other similar material. The rubberized abrasive masking tape absorbs the impact of the abrasive media and provides a seal as explained below. The rubberized abrasive masking tape preferably includes adhesive on at least one surface that facilitates connection of nozzle fitting  15  to the exterior front surface of bag portion  13 . In cases where nozzle fitting  15  is integral with bag portion  13 , nozzle fitting  15  may be the same thickness as bag portion  13 , or may be slightly thickened, if additional stiffness in the area of nozzle fitting  15  is desired. 
     Nozzle fitting  15  includes a nozzle aperture  23  that is adapted to sealingly receive a conventional blast nozzle  25  of a from a conventional blasting apparatus (not shown). Nozzle aperture  23  may be a circular, or other suitably shaped hole, or one or more slits, such as an X-shaped slit, in nozzle fitting  15 . In any case, the size of nozzle aperture  23  should be such that a seal is formed between nozzle fitting  15  and blast nozzle  25 , when blast nozzle  25  is inserted through nozzle aperture  23 . Such a seal prevents abrasive media  31  from escaping around nozzle aperture  23 . For example, nozzle aperture  23  would have a diameter in the range of about 0.312 to 0.350 inches to sealingly receive a blast nozzle having an outside diameter of about 0.375 inches. In cases where nozzle fitting  15  is a separate member connected to bag portion  13 , bag portion  13  includes an appropriately sized aperture over which nozzle fitting  15  is disposed. Although containment bag  11  has been illustrated with a square nozzle fitting  15  and a circular nozzle aperture  23 , it should be understood that nozzle fitting  15  and nozzle aperture  23  may be configured in other geometrical shapes, as other geometrical shapes may be more conducive for receiving, supporting, and sealing blast nozzles  25  having other shapes. 
     Blast fitting  17  is a reinforced portion of bag portion  13 , and is preferably centrally located on the rear surface of bag portion  13 . Blast fitting  17  may be integral with bag portion  13 , or may be a separate member that is connected to bag portion  13 . In cases where blast fitting  15  is a separate member connected to bag portion  13 , it is preferred that blast fitting  17  be made rubberized abrasive masking tape, such as the tape sold by the Anchor company as model BT100, 3M 500 stripping tape, or other similar material. Such rubberized masking tape is preferred because it absorbs the impact of the abrasive media and prevents blast fitting  17  from wearing out. It is preferred that the rubberized masking tape include an adhesive that does not leave a residue on the surface once blast fitting  17  is removed. If blast fitting  17  does not have adhesive on both sides to facilitate bonding to both bag portion  13  and aircraft surface  27 , then a separate adhesive, such as double-sided tape or glue may be used to facilitate connection of blast fitting  17  to the exterior rear surface of bag portion  13 . In cases where blast fitting  17  is integral with bag portion  13 , blast fitting  17  may be the same thickness as bag portion  13 , or may be slightly thickened if additional stiffness in the area of blast fitting  15  is desired. 
     It is preferred that blast fitting  17  be located on the rear surface of bag portion  13  such that blast fitting  17  and nozzle fitting  15  are aligned with each other, as is best seen in FIG.  3 . This configuration allows for a clearance C between nozzle fitting  15  and blast fitting  17  of about 4.0 inches when containment bag  11  is in use. Blast fitting  17  includes a blast aperture  29  that is adapted to isolate and surround the area to be treated. It will be appreciated that the size and shape of blast fitting  17  and the size and shape of blast aperture  29  may vary depending upon the desired application and surface to be treated. Although containment bag  11  has been illustrated with a circular blast fitting  17  and a concentric circular blast aperture  29 , it should be understood that blast fitting  17  and blast aperture  29  may be configured in other shapes and patterns, as other shapes and patterns may be more conducive for treating surfaces in other applications. For example, if a fastener has a square base that is to be bonded to aircraft surface  27 , it may be desirable that blast aperture  29  be square in shape; and if a part has a hatch pattern, it may be desirable to treat the surface to be bonded with a corresponding hatch pattern. 
     Filter member  19  is preferably located on the same surface of bag portion  13  as blast fitting  17 , and is sealingly attached to bag portion  13  by suitable means, such as by bonding, sewing, or gluing. It is preferred that filter member  19  be capable of filtering 99.5% or more of abrasive media  31  and releasing about 4.0 to 6.0 cubic feet of air per minute dispensed by the blasting device along with abrasive media  31 . In the preferred embodiment, filter member  19  is a 1.0 micron filter material about 0.125 inches thick and about 4.5 inches square. The passing of air through filter member  19  is represented in  FIG. 3  by arrows A. Although containment bag  11  has been illustrated with a square filter member  19 , it should be understood that filter member  19  may be configured in other shapes, as other shapes may be more conducive for filtering abrasive media  31  in various other applications. In addition, it should be understood that additional filter members may be used in certain applications, and that such additional filter members may be of the same capacity or of different capacities than filter member  19 . Indeed, the filtration of abrasive media  31  may be performed in multiple stages. 
     In operation, a protective sheet (not shown) is removed from the exterior surface of blast fitting  17  to expose the non-residue adhesive. Blast fitting  17  is then placed over an area  35  of surface  27  to be treated, where blast fitting  17  is secured in place by the adhesive. Then, nozzle  25  is inserted through nozzle aperture  23 , where nozzle  25  is sealingly held in place, preferably by a press fit. Once nozzle  25  is installed, the abrasive blasting treatment process is carried out in a conventional manner, with bag portion  13  capturing and collecting the abrasive media. After the blasting treatment is completed, blast fitting  17  is removed from surface  27  and containment bag  11  is discarded or otherwise disposed of. Then a click stud or other fastener can be bonded to the treated surface  27  in a conventional manner. 
     Although containment bag  11  has been shown and described primarily with respect to treating flat surfaces, it should be understood that the present invention may be used to enclose and treat three-dimensional objects. Referring now to  FIG. 4  in the drawings, an abrasive media containment bag  111  is shown in a three-dimensional application. As with containment bag  11 , containment bag  111  includes a bag portion  113 , a nozzle fitting  115 , a blast fitting  117 , and a filter member  119 . Nozzle fitting  115  includes a nozzle aperture  123 , and blast fitting  117  includes a blast aperture  129 . 
     In this application, both blast fitting  117  and blast aperture  129  are square in shape. This configuration is particularly well suited to allow access to all five sides of three-dimensional object  133  which protrudes outward from a surface  127 . As long as object  133  can be placed within bag portion  113 , and as long as bag portion  113  can be sealed around object  133 , the containment bag  111  can be utilized to isolate, contain, and recover the abrasive media. 
     It is apparent that an invention with significant advantages has been described and illustrated. Although the present invention is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof.