Abstract:
An inflatable restraint, and method of using the same, is used to provide support and shock isolation for missiles, torpedoes, missile canisters or the like in naval vessels. The inflatable restraint features a structural collar, at least one inflatable bladder and at least one interference member. The interference member is attached to the inside of the structural collar and the interference member is fully adjustable to ensure a snug fit during the loading of the missile, torpedo or missile canister into the structural collar. Once the missile, torpedo, missile canister or the like is properly inserted into the structural collar, the at least one inflatable bladder, which is also attached to the inside of the structural collar, is inflated to restrain the object. The pressure of the inflatable bladder may be regulated to provide variable spring constants and stiffness.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Application Serial No. 60/385,914 filed Jun. 6, 2002, and which is incorporated herein by reference. 
     
    
     
       FIELD OF INVENTION  
         [0002]    The invention relates to missiles and missile launchers, and more particularly, to the use of a pneumatic bladder or inflatable membrane to support a missile or missile canister and for providing resonant tuning of the support to different spring constants and stiffness through modification of the pressure within the bladder.  
         BACKGROUND OF THE INVENTION  
         [0003]    The loading of missiles, torpedoes, canisters or the like into naval vessels is often a time consuming task. There are two areas of concern for support of missiles: the support of the canister (the item which surrounds and protects the missile), and the support of the missile inside the canister.  
           [0004]    For surface ships, a vertical launch structure supports the missile canister. These canisters are locked into the structure using an apparatus to rigidly connect and align the aft end of the canister. This apparatus is called a “Dog-Down”. The Dog Down mechanism is a mechanical screw driven device with tapered wedges. These tapered wedges interface with a female receiver located on the missile canister. The tapered wedges on the Dog Down are drawn together by means of a reverse threaded shaft. This shaft, that passes through the wedges cause the wedges to move toward one another when the shaft is turned. The tapered wedges interface with the female receptacles on the missile canister, pushing the canister downward and sealing against the plenum surface on the launcher. Due to the rigid connection of the canister at the top of the launcher and at the dog-down interface, the entire launcher must be isolated from the ship to ensure shock loads are not transmitted to the missile round. This is a costly solution to the problem. Having a restraint mechanism at the launcher to canister interface would greatly simplify launcher designs and ship compatibility.  
           [0005]    For submarines, pads are located on the canister itself for isolation. The launch structure within a submarine is directly connected to a launch tube (no isolation between ship and launcher). Within the launch tube are raised pads whose location coincides with the isolation pads located on the missile canister. The pads, which have tapered-edges and a low friction coating, aid in the installation of the canister in the launch tube. The missile canister is constrained within the launch tube by a connection at the top. Also along the height of the canister are raised rubber pads that interfere with the raised edges in the launch tube, creating an interference fit. This fit provides the lateral support for the canister, and isolates the missile canister from the rest of the launch structure. A hydraulic jack is used to insert the missile canister into the launch tube. Due to the number of pads and the amount of surface area of interference, loads required to insert the missile canister can be as high as 40,000 lbs. In addition to the large loads required to install the missile canister, the time required to mobilize the equipment and insert the canister may be as long as 3 hours per missile. Also, during the hydraulic jacking process, the pads on the missile canister can pop off, jamming between the missile canister and launch tube preventing complete installation.  
           [0006]    For missile support, either sabots or snubbers are used to support the missile inside the canister. A sabot is a carrier inside the missile canister that provides support to the missile during shipping and transportation as well as during missile egress. The sabots are usually spring loaded against the missile and upon missile exit from the canister are ejected away from the missile. The sabots create a problem in ripple firing scenarios, since the ejected sabots could be in the flight trajectory of adjacent missiles. Snubbers, on the other hand, are retractable mechanisms within the canister that support the missile during shipping and transportation and fold down out of the way during launch, but always stay inside the canister. Snubbers are mechanical devices that have complex linkages that have reliability issues. In addition, since these linkages are rigid, loads outside the canister are transmitted directly into the missile.  
           [0007]    Other known art relies upon passive support, meaning it inflates once and is left alone. Also, because of material selection and support provided to the bladder, other known techniques can only operate at low pressures. The present invention is an active support and can operate at high pressures in excess of 200 pounds per square inch due to the combination of having a support structure and the use of reinforced fabrics. The support structure comprises the recessed groove of our design and supports the top, bottom and back of the bladder. The front of the bladder is supported by the canister or missile.  
           [0008]    The inflatable restraint in some fashion addresses all of the shortcomings associated with canister and missile support. The present invention is a constraining/clamping isolator that mitigates the need for having the launch structure entirely isolated. Isolation is occurring locally at the clamping interface by inflatable bladders. Also, when the bladders are deflated, ample clearance exists such that the missile canister no longer has to be hydraulically jacked into the launch tube as needed in the underwater launch configuration. The canister can simply be dropped in and the bladders inflated. For missile restraint, inflatable pads can replace the sabots. In this case, the invention behaves more like a snubber, but without the complicated linkages and the excessive load transfer into the missile.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention is an inflatable restraint used to provide support and shock isolation when securing missiles, torpedoes, canisters, or the like into a naval vessel. The inflatable restraint features a structural collar, with an inside and outside surface, having a perimeter and thickness. The inside surface of the structural collar has at least one recessed groove with at least one inflatable bladder lying within the groove. The inside surfaces of the structural collar features an interference member for the purpose of substantially aligning an object within the structural collar. A pressure regulator can regulate and change the spring stiffness of the inflatable bladder based on the shock requirements of the missile. The pressure regulator is operatively coupled to the inflatable bladder and a pressure source to pressurize and to inflate the bladder. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The above and other advantages and features of the present invention will be better understood from the following detailed description of the preferred embodiments of the invention, which is provided in connection with the accompanying drawings. The various features of the drawings may not be to scale. Included in the drawing are the following figures:  
         [0011]    [0011]FIG. 1 is a perspective view of a structural collar of the present invention.  
         [0012]    [0012]FIG. 2 is a perspective view of an alternative embodiment of the structural collar of the present invention.  
         [0013]    [0013]FIG. 3 is a perspective view of a structural collar of the present invention.  
         [0014]    [0014]FIG. 4 a  is a perspective view of an interference member of the present invention.  
         [0015]    [0015]FIG. 4 b  is a perspective view of an alternative embodiment of the interference member.  
         [0016]    [0016]FIG. 4 c  is a perspective view of an alternative embodiment of the present invention.  
         [0017]    [0017]FIG. 5 is a perspective view of the inflatable restraint.  
         [0018]    [0018]FIG. 6 is a perspective view of the inflatable restraint with alignment pin.  
         [0019]    [0019]FIG. 7 shows a missile in a canister and in an exploded view the missile being constrained by the inflatable bladder. 
     
    
     DETAILED DESCRIPTION  
       [0020]    [0020]FIG. 1 is a perspective view of the inflatable restraint  10  wherein a structural collar  11  has an inside surface  12  and an outside surface  13 , at least one recessed groove  14 , and at least one hole  15 . While the inflatable restraint  10  is shown as being substantially circular in shape, other shapes would not depart from the scope of the present invention. For example, the structural collar  11  may be any type of uniform or non-uniform geometry such as, but not limited to, a polygon, depending upon the type of object (e.g. missile, torpedo, missile canister) with which the structural collar  11  is to be used. The structural collar  11 , as shown in FIG. 1, is, preferably, of unitary construction having a thickness and perimeter. The thickness of the structural collar is defined as the measurement between the inside surface  12  and the outside surface  13 . Additionally, the structural collar  11  is made from a material that is known for being rigid and sturdy such as, (but not limited to), steel, or titanium.  
         [0021]    Recessed groove  14  is formed during the manufacture of the structural collar  11 , but in other embodiments the recessed groove  14  may be cut into the inside surface  12  of structural collar  11  after its manufacture. Recessed groove  14  protects an inflatable bladder (not shown in FIG. 1) when an object is loaded into the structural collar  11 . It is to be understood that recessed groove  14  is continuous. While FIG. 1 shows the inflatable restraint  10  with two recessed grooves  14 , one would realize that any number of recessed grooves  14  may be on the inside surface  12  of the structural collar  11 . If more than one recessed grooves  14  are featured, they are substantially parallel to each other.  
         [0022]    The structural collar  11  also features hole  15  that is cut through inner surface  12  and the outer surface  13  and around the perimeter of the structural collar  11 . Hole  15  allows a pressure regulator (not shown in FIG. 1) to attach, by means well known within the art, to an inflatable bladder (not shown in FIG. 1). For example, hole  15  may be threaded allowing for a pressure regulator and inflatable bladder to attach to each other.  
         [0023]    [0023]FIG. 2 is a perspective view of an alternative embodiment of the inflatable restraint  20  wherein the structural collar  11  has an inside surface  12 , an outside surface  13 , at least one recessed groove  14 , at least one hole  15 , and at least one mounting plate  21 . While the inflatable restraint  20  is shown as being substantially circular in shape, other shapes would not depart from the scope of the present invention. For example, the structural collar  11  may be any type of uniform or non-uniform geometry such as, but not limited to, a polygon, depending upon the type of object (e.g. missile, torpedo, missile canister) with which the structural collar  11  is to be used. The structural collar  11 , as shown in FIG. 2, is, preferably, of unitary construction having a thickness and perimeter. The thickness of the structural collar is defined as the measurement between the inside surface  12  and the outside surface  13 . Additionally, the structural collar  11  is made from a material that is known for being rigid and sturdy such as, but not limited to, steel, titanium, or the like.  
         [0024]    Recessed groove  14  is formed during the manufacture of the structural collar  11 , but in other embodiments the recessed groove  14  may be cut into the inside surface  14  of structural collar  11  after its manufacture. Recessed groove  14  protects an inflatable bladder (not shown in FIG. 2) when an object is loaded into the structural collar  11 . It is to be understood that recessed groove  14  is not continuous since mounting plate  21  is on the inside surface  12  of the structural collar II. While FIG. 2 shows the inflatable restraint  20  having two recessed grooves  14 , one of ordinary skill would realize that any number of recessed grooves  14  may be on the inside surface  12  of the structural collar  11  and, preferably, if more than one recessed grooves  14  are featured, recessed grooves  14  are substantially parallel to each other.  
         [0025]    The structural collar  11  also features hole  15  that is cut through inner surface  12  and the outer surface  13  and around the perimeter of the structural collar  11 . Hole  15  allows a pressure regulator (not shown in FIG. 1) to attach, by means well known within the art, to an inflatable bladder (not shown in FIG. 2). For example, hole  15  may be threaded allowing for a pressure regulator and inflatable bladder to attach to each other.  
         [0026]    [0026]FIG. 3 shows the inflatable restraint  10  or  20 , as described above, having at least one interference member  40  attached thereto. The interference member  40 , which is discussed in further detail below, may be attached anywhere on the inside surface  12  of the structural collar  11  of the inflatable restraint  10  or, in the alternative embodiment, interference member  40  attaches to mounting plate  21 . While FIG. 3 shows that three interference members  40  are attached to the structural collar  11 , any number of interference members  40  may be attached to the structural collar  11  without departing from the spirit of the present invention.  
         [0027]    The interference member  40  attaches to structural collar  11  by means well known within the art. For example, interference member  40  may be threadedly attached to structural collar  11 . In other embodiments, the interference member  40  may snap onto the structural collar  11 .  
         [0028]    [0028]FIG. 4 a  describes a perspective view of interference member  40  featuring connector  41  and front side  42 . Interference member  40  can be the shape of any polygon and is manufactured from a rigid and sturdy material such as, but not limited to, steel, titanium, or the like.  
         [0029]    Preferably, when an object (not shown) is inserted into the structural collar  11 , interference member  40  aligns the object ensuring that the object is only in contact with the at least one interference member  40  and not the inside surface  12  of the structural collar or the at least one inflatable member (not shown). The interference member  40 , in addition to aligning the object within the structural collar  11 , prevents the object from damaging the inflatable bladder.  
         [0030]    Interference member  40  also features connector  41  allowing the interference member  40  to attach to the inside of the structural collar  11 . For example, connector  41  may be a threaded hole in the back of interference member  40  or connector  41  may allow the interference member  40  to connect to structural collar by means of a snap connection. Regardless of the type of connector  41  that is used to attach interference member  40  to structural collar  11 , connector  41  also allows the interference member  40  to be adjustable through either a manual or automatic means.  
         [0031]    [0031]FIG. 4 b  shows a perspective view of the interference member  40  having a rubber cover  43  attached to its front side  42 . When an object is inserted into the structural collar  11  configured with the interference member  40  of FIG. 4 b , the object substantially touches rubber cover  43  thereby providing a friction fit between the object and interference member  40 . In other embodiments, since interference member  40  is adjustable, after the object is inserted into the structural collar  11 , the interference member  40  may be adjusted radially in order to provide a friction fit between the object and interference member  40  by means of the rubber cover  43 . While the term rubber is used, other materials known within the art may be used that are compressible.  
         [0032]    [0032]FIG. 4 c  shows a perspective view of the interference member  40  having at least one roller  44  attached to the front side  42  of the interference member  40 . Preferably, roller  44  is spring loaded allowing roller  44  to move in a radial direction with respect to the structural collar  11 . This alternative embodiment is, preferably, used with a structural collar  11  having an alignment pin (not shown), which is described below. As an object is inserted into the structural collar  11 , the roller  44  is substantially in contact with the object and roller  44  may move since it is spring loaded, as is well known in the art.  
         [0033]    [0033]FIG. 5 details the inflatable restraint  10  or  20 , as described above, having at least one pressure regulator  51  and at least one inflatable bladder  52 . Pressure regulator  51  is a conventional pressure regulator adapted to be used with inflatable restraint  10 . It is to be understood that pressure regulator  51  is operatively coupled to both a source (e.g. compressed air) and inflatable bladder  52 . The coupling may be any means well known within the art such as, but not limited to, a threaded or snap-like connection.  
         [0034]    Inflatable bladder  52  is attached to the inside surface  12  of structural collar  11  within a recessed groove  14  (not shown in FIG. 5). Inflatable bladder  52  can be attached to the structural collar  11  by means of an adhesive tape, rubber contact cement, stitches or retained by mechanical fasteners at the ends of the inflatable bladder  52 . The inflatable bladder  52  can be made from various materials such as, but not limited to, silicon, rubber, or a urethane coated fabric depending on the restrain and wear requirements. A variety of reinforcing fabrics may be used to increase the capacity of the inflatable bladder  52 . The reinforcing fabrics add additional strength to the inflatable bladder  52  in order for the present invention to operate under extreme conditions and reduce the wear of the inflatable bladder.  
         [0035]    Since the inflatable bladder  52  has a low modulus, it tends to have excellent isolation characteristics. Additionally, the aforementioned materials are ideal for shock isolation, where shock attenuation is the main goal. The size of the inflatable bladder is based upon shock analysis where the support area (contact area), load, and stiffness dictate the size and type of bladder. FIG. 5 details the use of discontinuous inflatable bladders  52  since each inflatable bladder  52  begins and ends next to interference member  40 . Since the inflatable bladder  52  is discontinuous, if an inflatable bladder  52  is damaged, it would be easy and less costly to replace. While a discontinuous inflatable bladder  52  is preferred, the inflatable restraint  10  may use at least one continuous inflatable bladder. Additionally, discontinuous inflatable bladders  52  are optimal when the structural collar  11  is a polygon.  
         [0036]    [0036]FIG. 6 details inflatable restraint  10  or  20  having structural collar  11  wherein inflatable bladder  52  is within a recessed groove (not shown in FIG. 6) on the inside surface  12  of inflatable restraint  10  or  20 . While the inflatable bladder  52  is shown in FIG. 6 as being substantially continuous, in other embodiments, the inflatable bladder  52  can be discontinuous allowing for a plurality of inflatable bladders  52  to be used.  
         [0037]    Alignment system  61  is attached to structural collar  11  by means well known within the art. As shown in FIG. 6, alignment system features a male connector  62  and the object (not shown if FIG. 6) features a female connection. In other embodiments, the alignment system can feature a female connector and the object has a male connector.  
         [0038]    In order to use the inflatable restraint  10  or  20 , an object, such as a missile  72 , shown within a canister  70  in FIG. 7, is inserted into the structural collar  11 . Preferably, when inserted, the missile  72  is substantially in contact with interference member  40  not shown. Inflatable bladder  52  is then inflated to constrain the missile  72  within canister  70 . The pressure of inflatable bladder  52  can be regulated to change the spring stiffness of the inflatable bladder based on the shock requirements of the missile. This can be done manually or under computer control known in the art. In other embodiments, once the object is inserted, interference member  40  is adjusted, by means well known in the art, in order to substantially touch the object. Next, the user operates the pressure regulator  51  causing inflatable bladder  52  to inflate and hold the object in place. Once the inflatable bladder  52  is inflated to its desired level, the inflatable restraint system  10  or  20  may support the object in either a lateral oryertical direction.  
         [0039]    Although illustrated and described herein with reference to certain specific embodiments, the present invention is nevertheless not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.