Patent Publication Number: US-7581481-B1

Title: Capsule for releasably retaining a missile

Description:
STATEMENT OF GOVERNMENT INTEREST 
   The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalty thereon or therefore. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to containers for submarine launched missiles and, more specifically, to a capsule for releasably retaining a missile, the capsule being adapted for disposition in a submarine launch tube and adapted to house the missile until launch thereof. 
   2. Description of the Prior Art 
   It is known to provide a capsule for retention of a missile, the capsule being adapted for disposition in a submarine launch tube. The capsule wall is made up of a composite of layers of graphite and glass fiber bonded with an epoxy resin. The layers, at their ends, abut titanium flanges. Urethane pads are adhesively bound to the outermost layer of glass fibers which forms the outer-skin of the capsule. 
   Experience has shown that contact between the graphite layers and the titanium flanges creates galvanic reaction within the composite wall. The reaction produces NaOH, and/or moisture and oxygen, which leaches out of the composite and deteriorates the adhesive bond between the urethane pads and the composite capsule, resulting in bond failures. 
   There is thus a need for a structure for preventing the NaOH and moisture and oxygen from contacting the adhesive layer binding the urethane pads to the capsule outer skin. 
   SUMMARY OF THE INVENTION 
   An object of the invention is, therefore, to provide an improved structure for the capsule composite wall, which structure prevents internally generated products of galvanic reaction from reaching the adhesive bonding the methane pads to the capsule outer skin. 
   With the above and other objects in view, a feature of the invention is the provision of a capsule for releasably retaining a missile, the capsule being adapted for disposition in a submarine vertical launch tube and for retaining the missile until launch thereof. The capsule comprises a cylindrically shaped housing made of a plurality of layers of glass fibers and layers of graphite, the layers including an outer layer of glass fibers defining an outer skin of the housing, and an inner layer of glass fibers disposed inboard of the outer layer of glass fibers. A titanium flange is fixed on the housing proximate either end thereof and in contact with the layers of graphite. An adhesive layer is disposed on the outer skin, and an interface support pad is mounted on the outer skin and retained thereon by the adhesive layer. A layer of metal foil is disposed inboard of the adhesive layer, and between the outer layer of glass fibers and the inner layer of glass fibers, to serve as a barrier to products of galvanic reaction occurring between the graphite layers and the titanium flange. 
   The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular device embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Reference is made to the accompanying drawings in which is shown an illustrative embodiment of the invention, from which its novel features and advantages will be apparent, wherein corresponding reference characters indicate corresponding parts throughout the drawings and wherein: 
       FIG. 1  is a side elevational view of a capsule for releasably retaining a missile; 
       FIG. 2  is an enlarged perspective view of a forward flange portion of the capsule of  FIG. 1 ; 
       FIG. 3  is a sectional view of the forward capsule portion and flange portion of  FIG. 2 ; 
       FIG. 4  is a sectional view of an after capsule portion and flange portion of the capsule of  FIG. 1 ; and 
       FIG. 5  is an enlarged, not-to-scale diagrammatic sectional view, taken through the composite skin of the capsule of  FIG. 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , it will be seen that a capsule  10  comprises an elongated cylindrically-shaped housing  12  which is adapted for disposition in a submarine vertical launch tube, or the like (not shown). The capsule  10  is adapted to house a missile (not shown) until the missile is launched from the capsule  10  and the submarine launch tube. The capsule  10  is configured to receive, carry, and support the launch of the missile. 
   Referring to  FIG. 2 , it will be seen that a forward end  14  of the capsule  10  includes a forward flange portion  16  which in turn includes an inner piece  18  and an outer piece  20 . Sandwiched between the forward flange portion inner and outer pieces  18 ,  20  is a forward end  24  of a wall structure  22  defining the housing  12 . A forward end  24  of the wall structure  22  abuts the inner piece  18  of the forward flange portion  16 . 
   Similarly, an after end  26  of the capsule  10  includes an after flange portion  28  which abuts an after end  30  of the wall structure  22 . 
   Referring to  FIG. 5 , it will be seen that the wall structure  22  of the capsule  10  includes multiple alternating layers  32 ,  34  of graphite sandwiched between an inside layer  36  of moisture barrier material and an outer layer  38  of glass fibers. A second layer  40  of glass fibers underlies the outer layer  38 . Additional layers (not shown) of glass fibers may be included in the composite. The graphite layers preferably comprise thin layers  32  of graphite and thicker layers  34  of graphite. The graphite and glass fiber layers are in combination with an epoxy matrix (not shown). The moisture barrier  36  preferably comprises a layer  42  of aluminum bound by inner and outer layers of glass cloth  44 ,  46 . 
   At either end of the capsule  10  there is provided a titanium flange  16 ,  28 , the flanges  16 ,  28  being in contact with the graphite layers  32 ,  34 . 
   On the outer surface  48  of the outer layer  38  of glass fibers, there is mounted an interface support pad  50  bound to the outer surface  48  by a layer  52  of adhesive. It is the adhesive layer  52  that is potentially deleteriously affected by NaOH and/or moisture and/or oxygen derived from galvanic activity at the interfaces of graphite layers  32 ,  34  and flanges  16 ,  28 . 
   In accordance with the invention, a metal foil  54  is disposed between the outer glass fiber layer  38  and another glass fiber layer there beneath, such as the layer  40 . The metal foil  54  underlies the adhesive  52  and the interface support pad  50  and blocks movement of deleterious matter from the composite to the adhesive layer  52 . 
   The interface support pads  50  abut the inside surfaces of a launch tube (not shown). The pads  50 , when viewed axially along the capsule, are of arcuate configuration such that a base thereof coincides with the surface configuration of the capsule  10 , and the outer surface thereof coincides with the internal curvature of the launch tube. Thus, the support pads  50  serve to maintain the capsule  10  centered in the launch tube. One set of pads  50  is disposed proximate a forward end  14  of the capsule  10  and a second set of pads  50  is disposed nearer the after end  26  of the capsule  10 . Each set typically includes four equally spaced and equally sized pads arranged circumferentially around the capsule. The metal foil  54  may comprise a discrete foil member underlying each pad or a belt of foil underlying all the pads of a set of pads  50 , wherein the metal foil  54  is of arcuate configuration such that a base surface thereof coincides with the surface configuration of the capsule  10 , and the outer surface thereof coincides with the internal curvature of the launch tube. 
   It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principles and scope of the invention as expressed in the appended claims.