Patent Publication Number: US-2016221690-A1

Title: Apparatus and method for facilitating bladder installation and removal

Description:
FIELD OF THE INVENTION 
     The present invention relates to the removal and re-installation or replacement of flexible fluid storage bladders from within support structures, and more particularly, to the removal and re-installation or replacement of airplane fuel bladders. 
     BACKGROUND OF THE INVENTION 
     Flexible storage bladders are used in various applications to provide a fluid tight storage volume within another structure designed to support the bladder. One example is the use of fuel bladders on airplanes, where one or more fluid bladders are located within the wings and/or fuselage of the airplane. 
     To ensure fluid-tightness and integrity, fluid bladders are typically removed from within their corresponding support structures for periodic inspections. If the fluid bladder is still intact and in acceptable condition, it is then re-installed; if not, the fluid bladder must be repaired or replaced. 
     For removal, the fluid bladder is typically emptied and any connection points (such as fluid plumbing fittings or the like) between the fluid bladder and the surrounding structure are disconnected. The fluid bladder is then withdrawn through an access opening in the structure. 
     During such removals, there is a significant risk of damaging the fluid bladder through interaction between the bladder and sharp surfaces at or around the access opening. The costs associated with the otherwise unnecessary repair or replacement of fuel bladders due to damage during removal can quickly become considerable. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide an apparatus and method for facilitating fluid bladder removal. According to an embodiment of the present invention, an apparatus for facilitating fluid bladder removal from a support structure through an access opening includes a frame defining a central opening dimensioned to conform to the access opening, the frame having opposed first and second surfaces and adapted to removably mount inside the support structure around the access opening, and a plurality of roller assemblies mounted to the first surface around the central opening. According to a method aspect, the apparatus is connected inside the support structure with the rollers extending away from and surrounding the access opening to facilitate passage of the fluid bladder. According to a further method aspect, the apparatus is connected outside the access opening to facilitate passage of the fluid bladder during installation. 
     These and other objects, aspects and advantages of the present invention will be appreciated in view of the drawings and following description of a preferred embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a bottom view of an apparatus for facilitating fuel bladder removal, according to an embodiment of the present invention; 
         FIG. 2  is a top view of the apparatus of  FIG. 1 ; 
         FIG. 3  is a side view of the apparatus of  FIG. 1 ; 
         FIG. 4  is a perspective view of the apparatus of  FIG. 1 , installed inside an access opening of a support structure; and 
         FIG. 5  is a perspective view of the apparatus of  FIG. 1  in use during removal of a fuel bladder from the support structure of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-3 , an apparatus  10  for facilitating fluid bladder removal includes a frame  12  with a plurality of roller assemblies  14  mounted thereto. The frame  12  defines a central opening  16  that is dimensioned to closely conform to the shape of an access opening of a support structure from which a fuel bladder will be removed. The plurality of roller assemblies  14  substantially surround the central opening  16  and are rotatable to facilitate the passage of the fuel bladder therethrough. 
     The frame  12  includes a first surface  20  and a generally opposed second surface  22 . The roller assemblies  14  are mounted to the first surface  20  and bolts  24  or other connectors extend away from the second surface  22  to facilitate connection within the access opening. Many structures holding fluid bladders will have various structural elements arranged along inside surfaces thereof, such as stringers, struts and the like. A spacer  26  extends away from the second surface  22  to eliminate interference between the roller assemblies  14  and any such structural elements. Likewise, to ensure the frame  12  does not interfere with such structural elements, accommodation notches  28  can be formed along a periphery of the frame  12 . 
     The number and design of notches  28 , as well as the overall dimensions of the frame  12  and spacer  26  can vary depending on the support structure and fuel bladder for which the apparatus  10  is designed. Exemplary thicknesses for the frame and spacer include ¼ inch and 2 inches, respectively. Aluminum construction is advantageous for lightness and durability. In the depicted embodiment, the frame  12  and spacer  26  are separate structures, held together by the bolts  24  which extend from the second surface  22  of the frame  12  and through the spacer  26 . Countersunk nuts (not shown) can be used to hold the spacer  26  to the frame  12  while still permitting the spacer to fit flush against the support structure around the insider of the access opening. Alternately, an integral frame and spacer could be used. 
     The roller assemblies  14  include two pairs of generally opposed side rollers  30  and two pairs of corner rollers  32  arranged between ends of the side rollers  30 . The rollers in each opposed pair  30  are mounted along generally parallel axes of rotation, with the rotational axis of each side roller  30  being generally perpendicular to the adjacent side roller  30 . The axes of rotation of the corner rollers  32  are offset approximately 45 degrees from each axes of rotation of its adjacent side rollers  30 . The roller assemblies  14  each include mounting mechanisms  34  for rotational connection to the frame  12 , with the mounting mechanisms  34  connected to the first surface  20 . 
     The present invention is not necessarily limited to the depicted frame  12  shape, or roller assembly  14  mounting locations. It will be appreciated that the dimensions of the frame  12  and opening  16  can be adapted depending on the access opening in connection with which the apparatus  10  is intended for use. Similarly, the number and configurations of the roller assemblies  14  can also be modified. Advantageously, the rollers  30 ,  32  are shaped so that their inner peripheries collectively conform very closely to the shape of the central opening  16 , and likewise to the opening in the rigid structure, and are aligned therewith. 
     Referring to  FIG. 4 , the apparatus  10  is connected inside the access opening  40  of a support structure  42 , such as an airplane wing or fuselage. A plurality of bores  44  extends around the opening  40 , which bores  44  are utilized to connect the opening  40  with the bladder and/or an access cover during normal use. The bolts  24  on the second surface  22  of the frame  12  are inserted through some of these bores  44 , with which they are aligned, and secured with nuts  46 . The apparatus  10  is thereby securely held around the inner side of the access opening  40 , with the central opening  16  of the frame aligned therewith. 
     Referring to  FIG. 5 , the roller assemblies  14  effectively smooth the transition of a fluid bladder  50 , such as a fuel bladder, when passing out of (or back into) the structure  42  through the opening  40 . It has been determined that use of the apparatus  10  greatly facilitates the removal of the bladder  50  through the access opening  40 , both speeding up the process of removal and minimizing the risk of damage to the bladder. 
     In addition to facilitating bladder  50  removal, the apparatus  10  can be employed to facilitate bladder  50  installation. If already connected, the apparatus  10  is disconnected from inside the access opening  40  and removed therefrom. The apparatus  10  is then connected outside the access opening  40  with the second surface  22  and spacer  26  facing the outer surface of the support structure  42  and the bolts  24  extending through the bores  44  into the interior space. The apparatus  10  can again be secured with nuts  46 , attached to the bolts  24  inside the access opening  40 . The bladder  50  in then inserted through the access opening  40 , with its passage eased by the roller assemblies  14 . When no longer required, the apparatus  10  is removed and stored for later use. 
     In general, the foregoing description is provided for exemplary and illustrative purposes; the present invention is not necessarily limited thereto. Rather, those skilled in the art will appreciate that additional modifications, as well as adaptations for particular circumstances, will fall within the scope of the invention as herein shown and described and of the claims appended hereto.