Abstract:
The launcher closure with outer cover is adapted to fit on a canister that contains a missile or the like thereby sealing the inside of the canister from the external environment and allowing the missile to be tested. The closure is designed to move only in the event of a fast rise in pressure caused by launch, but to remain in place in the occurrence of a slow pressure leak. The closure is in a predetermined shape such as a cylinder or the like with one end of the tube containing an O-ring to seal the canister and closure, and the other end of the closure with a surface. The closure, when attached to the canister, seals the inside of the canister from the external environment.

Description:
[0001] This invention was made with Government support under Contract No. DASG60-00-C-0072 awarded by the Department of Defense. The Government has certain rights in this invention. 
     
    
     
       FIELD OF INVENTION  
         [0002]    The invention relates to a missile canister and, in particular, to a missile canister having a pressure sensitive cover.  
         BACKGROUND OF THE INVENTION  
         [0003]    Weapons such as missiles whether on land or on naval vessels are currently stored in canisters that protect the weapon from the external environment during transportation. The canister that houses the missile is, typically, an elongated tube having at least one opening wherein a cap is placed on the opening effectively sealing the canister.  
           [0004]    When the missile, or the like, is launched, several methods have been proposed allowing the missile to egress from the canister. One system has a cap composed of a lightweight material attached to the canister. When the missile is launched and egresses from the canister, the missile strikes the cap thus causing the cap to fracture. However, this cap which permits moisture and other external elements inside the canister may cause the missile to malfunction. Additionally, when the missile strikes the cap, the cap projects debris in a random manner with ensuing damage to the missile.  
           [0005]    Another method has a pyrotechnic device within, or near, the cap, wherein the device is operatively coupled to the missile. As the missile is launched, the pyrotechnic device is activated causing the cap to decouple from the canister allowing the missile to egress from the canister unencumbered. Unlike the first method wherein fragments of the cap are projected in a random manner, the entire cap is released from the canister. By fitting a cap with a pyrotechnic device, the missile cannot be periodically tested since the pyrotechnic device activates upon the firing of the missile.  
           [0006]    The problem is that no canister and cap allows the missile, or the like, to be tested or to be protected from the external environment.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention features a cap covering an opening of an elongated canister wherein the canister has at least one open end. The cap has an inner cover with two ends. A first end of the inner cover is enclosed and an outer cover has two ends wherein a first end of the outer cover is enclosed. Both the inner cover and outer cover are operatively coupled to each other. Between the first and second end of the outer cover is a surface having at least one hole wherein at least one protrusion projects from the hole.  
           [0008]    In another embodiment, the present invention features a cap wherein the cap has a pressure sensitive system and at least one protrusion protruding in a radial direction to the cap. The pressure sensitive system is operatively coupled to at least one protrusion. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    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:  
         [0010]    [0010]FIG. 1 is a perspective view of the launcher closure.  
         [0011]    [0011]FIG. 2 is a perspective view of the outer cover of the launcher closure.  
         [0012]    [0012]FIG. 3 is a perspective view of the bearing seal that is within the outer cover of the launcher closure.  
         [0013]    [0013]FIGS. 4 a  and  4   b  are a view of the launcher closure attached to a canister. 
     
    
     DETAILED DESCRIPTION  
       [0014]    [0014]FIG. 1 details the launcher closure  10  having inner cover  11  and outer cover  21 . While FIG. 1 shows that inner cover  11  and outer cover  21  are substantially circular in shape, other shapes can be utilized without departing from the spirit of the present invention. For example, inner cover  11  and outer cover  21  can be in the shape of rectangles known within the art or inner cover  11  and outer cover  21  can be any polygon shape.  
         [0015]    Inner cover  11 , as shown in FIG. 1, has two ends wherein the first end is substantially enclosed and the second end is, preferably, not enclosed (not shown in FIG. 1). The first end of inner cover  11  has a plurality of holes and the surface that intersects between the two ends is tapered (See FIGS. 4 a  and  4   b ).  
         [0016]    Outer cover  21  features a substantially continuous surface having two ends. The first end of the outer cover  21  is substantially enclosed by a second surface and the second end is not enclosed. Preferably, formed, by means well known in the art, to the second end of the outer cover  21  is at least one groove  23  that is substantially the same shape as the opening of a canister (not shown in FIG. 1). While groove  23  is described as being attached to outer cover  21 , it would not depart from the spirit of the present invention to have groove  23  and outer cover  21  to be of unitary construction. Groove  23  is substantially continuous and, preferably, an O-ring or the like is placed within thereby effectively sealing the inside of the canister when launcher closure  10  is attached. Additionally, the O-ring protects the contents of the canister from electro magnetic interference.  
         [0017]    The outer cover  21  also features a plurality of protrusions  22  substantially perpendicular to the enclosed second surface. The protrusions  22  substantially align with the holes in the first surface of the inner cover  11  allowing both the inner cover  11  and the outer cover  21  to be attached by a conventional means. For example, a hole can be cut at a predetermined place within the protrusions  22  and a cotter pin, or the like, can be used to fasten the inner cover  11  to the outer cover  21 .  
         [0018]    Projecting in the radial direction with respect to outer cover  21  is a plurality of ball bearings  14 , or the like. Preferably, the open end of the canister (not shown in FIG. 1) features a continuous groove within the inside of the canister or the groove can be placed on the outside of the canister. In other embodiments, holes, divots, or the like can be placed at predetermined points around the inside of the canister. The holes or continuous grove allow the ball bearings  14 , or the like, to create a frictional attachment permitting the launcher closure  10  to be releasably attached to the open end of an elongated canister. While the launcher closure  10  describes the use of ball bearings  14  that releasably attach it to the open end of an elongated canister, other embodiments can exist. For example, roller bearings, or the like, can project in the radial direction to the outer cover  21  allowing the closure  10  to releasably attach to the open end of an elongated canister.  
         [0019]    While not shown in FIG. 1, it is to be understood inner cover  11  fits within outer cover  21  and these elements are operatively coupled together, which is described below.  
         [0020]    [0020]FIG. 2 is a detailed view of outer cover  21  having protrusions  22 , groove  23  and a plurality of holes  24 , as substantially described above. Outer cover  21  is a substantially continuous surface, as described above, which fits inside the opening of a canister (not shown). Holes  24  are cut within the surface of outer cover  11  allowing the ball bearings  14 , or the like, to project in a radial direction. While not detailed in FIG. 2, holes  24  may be cut at an angle allowing the ball bearings  14 , or the like, to retract easily.  
         [0021]    [0021]FIG. 3 is a detailed view of bearing ring  30 . While bearing ring  30  is shown as being substantially circular in shape, it is to be understood that bearing ring  30  can be any shape known within the art and additionally, bearing ring  30  can be substantially the same shape as outer cover  21  since bearing ring  30  fits within inner cover  11 , thereby integrating the feature of bearing ring  30  within inner cover  11 . Bearing ring  30  is a substantially continuous surface wherein a plurality of spring holes  31  is cut into its surface. It should be appreciated, that spring holes  31  can be cut entirely through bearing ring  30  or that spring holes  31  can be cut partially through the bearing ring  30 . Additionally, a plurality of protrusion holes  32  is cut through the surface of the bearing ring  30 . Protrusion  22  is aligned and placed through protrusion hole  32  allowing bearing ring  30  to be connected to outer cover  21 . The overall width of bearing ring  30 , shown in FIG. 3 as W b , is smaller than the width of outer cover  21 . Therefore, when the launcher closure  10  is attached to the open end of a canister, there will be a gap within the closure  10 , which is described below.  
         [0022]    While bearing ring  30  is described as a separate element that attaches to outer cover  21  by the protrusion  22 , it would not depart from the spirit of the present invention to integrate the features of bearing ring  30  within inner cover  11 .  
         [0023]    [0023]FIG. 4 a  details the launcher closure  10  attached to the open end of canister  41 . While launcher closure  10  is shown as being attached to the inside surface of canister  41 , the launcher closure  10  may be attached to the outside of the canister  41 . Canister  41  is a conventional canister notoriously well known within the art.  
         [0024]    The launcher closure  10  features inner cover  11 , ball bearing  14 , outer cover  21 , protrusion  22 , groove  23 , bearing ring  30 , spring cavity  31 , canister  41 , canister groove  42  and spring  43 . As shown in FIG. 4 a  and discussed above, it is to be understood that bearing ring  30  is placed within inner cover  11  and inner cover  11  and bearing ring  30  are aligned enabling the protrusion  22  to slide through protrusion hole  32  and the hole within inner cover  11  allowing the system to be secured together. While bearing ring  30  and inner cover  11  are described as being two distinct elements, it would not depart from the scope of the present invention to integrate bearing ring  30  within inner cover  11 , that is, there may be only one ring and bearings sit directly on it.  
         [0025]    As shown in FIG. 4 a , it is to be understood that little pressure is being exerted against inner cover  11 . Ball bearing  14  is within canister groove  42  since the tapered edge of inner cover  11  is substantially pressing ball bearing  14  into canister groove  42 . The edge of inner cover  11  prevents ball bearing  14  from moving thereby creating a frictional connection between the launcher closure  10  and canister  41 . Groove  23  contains an O-ring, or the like, effectively sealing the inside of the container from the external environment.  
         [0026]    Spring  43  is contained within spring cavity  31  and is placed against the bottom of outer cover  21  and either bearing seal  30 . Since there is little pressure being exerted upon inner cover  11 , spring  43  is not substantially compressed and a gap  44  is formed. Typically, a missile (not shown) or the like held in canister  41  leaks a toxic missile propellant. During these leaks, the pressure within the canister slowly rises. However, ball bearings  14  will not disengage from the canister groove  42  allowing launcher closure  10  to be attached to canister  41 . While the launcher closure  10  is described as utilizing a spring, it would not depart from the spirit of the present invention to use other pressure sensing devices.  
         [0027]    [0027]FIG. 4 b  details the launcher closure  10  has a pressure, P, exerted against inner cover  11 . The launcher closure  10  is designed to release from the opening of the canister  41  when the missile (not shown) is fired and a pressure pulse is exerted against the inner cover  11 . This pressure causes spring  43  to compress against outer cover  21  and bearing seal  30 . Inner cover  11  moves in an upwardly direction thereby causing gap  44  shown in FIG. 4 a  to decrease until inner cover  21  is substantially touching outer cover  21 . When there is little, or no, gap  44  between inner cover  11  and outer cover  21 , the tapered edge of inner cover  11  is no longer pressing against ball bearing  14  causing ball bearing  14  to retract from its position. Once ball bearing  14  retracts, launcher closure  10  is removed from the opening of canister  41  by the pressure exerted on it.  
         [0028]    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 without departing from the spirit of the invention.