Abstract:
The illustrative embodiment of the present invention is a munitions launch system. The launch system comprises a canister and a cold launch system. In the illustrative embodiment, the cold launch system comprises a sled and a release system. In the illustrative embodiment, the release system includes a sled release mechanism, which releasably secures the sled to the munitions canister, and a munitions release mechanism, which releasably secures a munition to the sled. Actuation of the sled release mechanism releases the sled for movement within the canister. After the sled moves some minimal distance under applied force, the munitions release mechanism “automatically” actuates, releasing the munition from the sled so that the munition can be ejected from the canister.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to canistered munitions, and more particularly to launch mechanisms for canistered munitions.  
       BACKGROUND OF THE INVENTION  
       [0002]     It is well known in the art to launch a missile from a canister. Missiles are launched from canisters using either a “hot” launch technique or a “cold” launch technique.  
         [0003]     During hot launch, the missile&#39;s motor ignites while the missile is in the canister. The motor provides the thrust that is required to propel the missile from the canister. During cold launch, an ancillary system is used eject the missile from the canister; that is, the missile&#39;s motor does not ignite until after the missile leaves the canister. In some cold launch systems, the ancillary system comprises a sled or base upon which the missile rests. During launch, the sled and the missile are accelerated toward the front end of the canister. The sled is abruptly stopped at the forward end of the canister while the missile exits the canister due to its inertia.  
         [0004]     A restraint/release mechanism (hereinafter simply “release” mechanism) normally secures the missile within the canister prior to launch to prevent damage to the missile and to maintain its orientation within the canister. Of course, this mechanism must release the missile for launch.  
         [0005]     Hot launch systems employ either an active release mechanism, such as explosive bolts, or a passive release mechanism, such as a combination of springs and latches. When a passive mechanism is used, missile motor ignition is often used to trigger the passive mechanism into release. See, for example, U.S. Pat. No. 4,550,640. Of course, that technique is only suitable for hot launch, since the missile does not ignite within the canister during cold launch. Cold launch systems, especially those that include a sled or base to accelerate the missile, often use two release mechanisms, which are typically active mechanisms. The first mechanism releasably couples the sled or base to the canister and the second mechanism releasably couples the missile to the sled.  
         [0006]     There is a risk that the release mechanism will not release during launch. This results in a restrained firing, which can cause damage to the canister, canister internals, and the missile itself. This risk is typically greater for a cold launch system than a hot launch system, and the risk is especially elevated for a cold launch system that uses two release mechanisms.  
         [0007]     There is a need, therefore, for a release mechanism that substantially prevents the possibility of a restrained firing during launch of a canistered munition.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention provides a release system for canistered missiles, especially for cold-launched canistered missiles, which avoids some of the costs and disadvantages of the prior art.  
         [0009]     In the illustrative embodiment, a munitions launch system comprises a canister and a cold launch system. The cold launch system comprises a sled and a release system.  
         [0010]     The sled is initially restrained within the canister near the aft end, but is released during launch. During launch, the sled moves toward the forward end of the canister under an applied force, pushing a munition, such as a missile, along with it. When the sled is abruptly stopped at the forward end of the canister, the missile is ejected from the canister by virtue of its own inertia.  
         [0011]     In the illustrative embodiment, the release system includes two release mechanisms: 
        a sled release mechanism, which releasably secures the sled to the munitions canister; and     a munitions release mechanism, which releasably secures the munition to the sled. 
 
 In the illustrative embodiment, the sled release mechanism is an active release mechanism and the munitions release mechanism is a passive release mechanism. 
       
 
         [0014]     As used in this specification, the phrase “active release mechanism” refers to a release mechanism that actuates under its own power. An example of an active release mechanism is an explosive bolt. The bolt includes an explosive charge that, when ignited, frees whatever structure is being restrained by the bolt.  
         [0015]     As used in this specification, the phrase “passive release mechanism” refers to a release mechanism that is triggered by an ancillary event or mechanism that is not, per se, a part of the passive release mechanism. An example of such an ancillary event is a change in state (e.g., position, velocity, orientation, etc.) of a member (ancillary member) that is operatively coupled to or otherwise affects a passive release mechanism, but that is not a part of that passive release mechanism.  
         [0016]     The release system used in conjunction with the illustrative embodiment of the invention operates as follows. The sled release mechanism, which in the illustrative embodiment is a plurality of explosive bolts, is actuated first. This releases the sled for movement within the canister. After the sled moves some minimal distance under applied force (e.g., pressure, pneumatics, hydraulics, electromagnetics etc.), the munitions release mechanism “automatically” actuates. This releases the munition from the sled so that the munition can be ejected from the canister.  
         [0017]     In the illustrative embodiment, the munitions release mechanism comprises a pivotable latch, a movable trigger pin, and an immovable support pin.  
         [0018]     The latch is disposed on the upper surface of the sled and is positioned so that it can releasably engage notches that are formed in the casing of the munition. The latch pivots between an “anchoring” position and a “release” position. In the anchoring position, the latch engages a notch, thereby securing the munition to the sled. In the release position, the latch disengages from the notch, releasing the munition from the sled. As described below, the position of the latch is dictated, ultimately, by movement/position of the sled.  
         [0019]     The trigger pin is disposed partially within a hole that passes through the sled. The trigger pin slides freely up or down through this hole, moving between a “supporting” position and a “triggering” position as a function of the position of the sled.  
         [0020]     In the supporting position, the trigger pin is extended to a maximum distance beyond the upper surface of the sled. The trigger pin is urged forward into the supporting position when the sled is at its most aft location in the canister (i.e., before the sled is released). In this position, the trigger pin is supported by the underlying immovable support pin, which is permanently secured near the aft end of the canister. The support pin forces the trigger pin into contact with the latch and prevents the latch from pivoting away from its anchoring position.  
         [0021]     As the sled moves toward the forward end of the canister, the trigger pin loses the support of the underlying immovable support pin. Unsupported, the trigger pin falls out of contact with the latch and into the triggering position, dropping some distance within the hole in the sled. The latch is then free to pivot to the release position, which it does, urged by gravity, a spring bias, etc. This releases the munition from the sled.  
         [0022]     The arrangement of: 
        a sled release mechanism (either actively or passively actuated) for releasing the sled from the canister;     and a munition release mechanism (passively actuated) for releasing the munition from the sled, wherein the munition release mechanism actuates as a function of movement/position of the sled . . . 
 
 ensures that if the sled releases from the canister, the munition will decouple from the sled. This substantially eliminates the possibility of a restained launch, which might occur in a system in which the munition must actively release from the sled.
       
 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]      FIG. 1  depicts a launch system in accordance with the illustrative embodiment of the present invention.  FIG. 1  depicts the launch system in a pre-launch state.  
         [0026]      FIG. 2  depicts the launch system of  FIG. 1  during launch, after the sled has moved a distance D.  
         [0027]      FIG. 3  depicts a partial cross-sectional view of an embodiment of the sled and munitions release mechanisms of the launch system of  FIG. 1 .  FIG. 3  depicts the mechanisms in a pre-launch state.  
         [0028]      FIG. 4  depicts the mechanisms of  FIG. 3  during launch, after the sled has moved distance D. 
     
    
     DETAILED DESCRIPTION  
       [0029]      FIG. 1  depicts a simplified partial view of launch system  100  in accordance with the illustrative embodiment of the present invention. Launch system  100  includes canister  102 , sled  104 , force generator  106 , sled release mechanism  108 , and munitions release mechanism  110 .  FIG. 1  depicts launch system  100  in a pre-launch state.  
         [0030]     It will be understood that launch system  100  typically includes other internal parts and mechanisms. These other internals are not depicted since they are well known to those skilled in the art and not germane to an understanding of the present invention.  
         [0031]     As depicted in  FIG. 1 , sled  104  is disposed near aft end  112  of canister  102  in pre-launch position P. Sled release mechanism  108  and munitions release mechanism  110  are operatively coupled to sled  104 . In particular, sled release mechanism  108  releasably couples sled  104  to aft end  112  of canister  102 . And munitions release mechanism  110  releasably couples munition  114  to sled  104 .  
         [0032]     Sled release mechanism  108  and munitions release mechanism  110  prevent sled  104  and munition  114  from moving prior to launch. After release, such as is depicted in  FIG. 2 , sled  104  is free to move toward forward end  216  of canister  102  and munition  114  is free to exit the canister.  
         [0033]      FIG. 2  depicts system  100  during launch, after sled  104  has moved a distance D. Sled release mechanism  108  is actuated to release sled  104  from canister  102 . (Actuation of sled release mechanism  108  and release of sled  104  is signified by the absence of the sled release mechanism in  FIG. 2 .) Force generator  106  provides force F that urges sled  104  into motion.  
         [0034]     In some embodiments, force generator  106  is a gas generator. The gas generated by the gas generator rapidly fills and pressurizes the region aft of sled  104 . The pressure accelerates the sled and munition  114  toward forward end  216  of canister  102 . See, e.g., U.S. patent application Ser. No. ______ (Atty. Dkt. 711-044), incorporated herein by reference. In some other embodiments, the motive force can be, without limitation, hydraulic, pneumatic, and electromagnetic, as supplied by appropriate mechanisms.  
         [0035]     By the time sled  104  has moved distance D from its pre-launch position, P, munitions release mechanism  110  is actuated, thereby releasing munition  114  from the sled. (This is signified by the absence of the munitions release mechanism in  FIG. 2 .) Munitions release mechanism  110  is physically configured so that release occurs passively based on the movement or position of sled  104 .  
         [0036]      FIGS. 3 and 4  depict a partial view of launch system  100 , and show, in greater detail, the illustrative embodiment of munitions release mechanism  110  as well as other structural details. The structural configuration of munitions release mechanism  110  that is depicted in these Figures, like all embodiments of munitions release mechanism  110  in accordance with the present invention, satisfies the requirement that the munitions release mechanism actuates passively as a function of the movement or position of sled  104 .  
         [0037]      FIG. 3  depicts launch system  100  in a pre-launch state, before sled  104  has been released. In the illustrative embodiment, sled release mechanism  108  is realized as a plurality of explosive bolts  338  (i.e., an active release mechanism). The explosive bolts releasably secure sled  104  to aft end  112  of canister  102 . In a typical implementation, four bolts  338  are disposed about a marginal region of sled  104  at 90-degree intervals. For clarity, only one explosive bolt is depicted in  FIG. 3 .  
         [0038]     In the illustrative embodiment, munitions release mechanism  110  is a group of cooperating elements comprising pivotable latch  324 , movable trigger pin  332 , and immovable support pin  336 . In a typical implementation, four such groups of these cooperating elements are disposed at 90-degree intervals around munition  114 . For clarity, only one group of these cooperating elements is depicted in  FIG. 3 .  
         [0039]     Latch  324  is disposed on upper surface  322  of sled  104 . Latch  324  includes nose portion  326 , tail portion  328 , and pin  330 . Latch  324  is capable of pivoting or partially rotating about pin  330  from an anchoring position to a release position. In the pre-launch state depicted in  FIG. 3 , latch  324  is in the anchoring position, wherein nose portion  326  engages notch  318  in the casing of munition  114 .  
         [0040]     As described further below, since tail portion  328  of latch  324  is supported by trigger pin  332 , which is, in turn, supported by support pin  336 , latch  324  is prevented from pivoting out of the anchoring position when launch system  100  is in the pre-launch state.  
         [0041]     Beginning now at aft end  112  of canister  102 , support pin  336  is immovably coupled to flange  334 . The flange is, in turn, coupled to canister  102 . In the pre-launch state depicted in  FIG. 3 , support pin  336  extends into hole  320  within sled  104 . The top of support pin  336  abuts the bottom of trigger pin  332 , which is also partially disposed in hole  320 .  
         [0042]     In the pre-launch state that is depicted in  FIG. 3 , trigger pin  332  extends to a maximal distance M beyond upper surface  322  of sled  104  at which point it abuts tail portion  328  of latch  324 . It will now be appreciated that in this pre-launch state, the support pin  336  and trigger pin  332  form a rigid column that prevents latch  324  from pivoting about pin  330  out of the anchoring position.  
         [0043]      FIG. 4  depicts launch system  100  during launch, shortly after explosive bolts  338  have fired. Since the explosive bolts have fired, sled  104  is free to move upward toward the forward end of canister  102 . It is assumed that the force generator (not depicted in  FIG. 4 , see, e.g.,  FIGS. 1 and 2 ) generates a force that causes sled  104  to accelerate upward through canister  102 . In a relatively short period of time, sled  104  and munition  114  will reach the forward end of canister  102 , at which point the munition is ejected by virtue of its own inertia. In  FIG. 4 , however, sled  104  is depicted after having moved a relatively short distance D.  
         [0044]     As sled  104  moves forward in canister  102 , trigger pin  332  loses the support of support pin  336 , which is fixed to aft end  112  of canister  102 . Since hole  320  is sized so that both support pin  336  and trigger pin  332  can freely slide within it, trigger pin  336  drops downward into the hole into the triggering position. In the illustrative embodiment, a stop (not depicted) prevents trigger pin  332  from falling completely through hole  320 .  
         [0045]     As trigger pin  332  drops into hole  320 , it loses contact with tail portion  328  of latch  324 . Latch  324  is configured to pivot about pin  330  to the release position when tail portion  328  is unsupported. In some embodiments, this is achieved by weighting tail portion  328 . In some other embodiments, latch  324  is spring biased to pivot. In any case, having lost the support of trigger pin  332 , latch  324  pivots around pin  330  to the release position. This releases munition  114  from sled  104 .  
         [0046]     It is appreciated that latch  324  will pivot from the anchoring position to the release position with only a slight change in position (e.g., an inch) of sled  104 . This distance is a function of the relative sizing and shape of nose portion  326  of latch  324  and the shape of notch  318  of munition  114 .  
         [0047]     So, in the pre-launch state, support pin  336  and trigger pin  332  place and maintain latch  324  in the anchoring position. After sled  104  is released, such as by sled release mechanism  108  (e.g., explosive bolts  338 , etc.), and has moved a small distance toward the forward end of canister  102 , trigger pin  332  loses its support and moves to the triggering position. This enables (triggers) latch  324  to pivot out of contact with munition  114  to its release position.  
         [0048]     In this fashion, munitions release mechanism  110  is actuated by movement/change in position of sled  104 . So released, munition  114  is free to eject from canister  102  when suitably accelerated by sled  104 .  
         [0049]     It is to be understood that the above-described embodiments are merely illustrative of the present invention and that many variations of the above-described embodiments can be devised by those skilled in the art without departing from the scope of the invention. For example, in the illustrative embodiment, the sled release mechanism that releasably couples sled  104  to canister  102  is an active release mechanism. In some other embodiments, the sled release mechanism is a passive release mechanism, although it is configured different than munitions release mechanism  110 .  
         [0050]     The alternative embodiments listed above are a few of the many variations that will occur to those skilled in the art after reading this disclosure. It is therefore intended that such variations, and others that will occur to those skilled in the art in view of the present disclosure, be included within the scope of the following claims and their equivalents.