This disclosure relates generally to the field of munitions. More particularly, it pertains to an apparatus and method for loading burster tubes such as the M54 A1 Burster tubes.
Burster tubes are structures that contain an energetic mix and are placed into projectiles that produce—for example—smoke upon detonation. The proper loading of a burster tube is of critical importance to their successful deployment and use.
Such an advance in the art is made according to an aspect of the present disclosure directed to structures and methods for loading burster tubes such as may be used—for example—in 155 mm projectiles.
Viewed from a first aspect, the present disclosure is directed to a burster tube loading assembly comprising a cooling chamber, a plurality of receiving fixtures each including a weep hole, and a distribution fixture having a heating/cooling manifold/chamber for preheating the distribution fixture. When a plurality of unloaded burster tubes are positioned within the cooling chamber—each in a respective receiving fixture, the tubes may be continuously and simultaneously loaded with an energetic mixture via the preheated distribution fixture positioned at a top of the chamber. Advantageously, weep holes positioned within the receiving fixture permit any trapped air to escape during loading thereby ensuring a uniform load. Finally, ports disposed along the sides of the cooling chamber permit the selective cooling/solidification of the energetic mixture after loading portions of the burster tubes thereby ensuring a uniform, solid mix.
Viewed from another aspect, the present disclosure is directed to a method for loading burster tubes. According to this aspect, unloaded burster tubes are positioned within a cooling chamber having a plurality of receiving fixtures with weep holes. A distribution fixture is positioned on a top portion of the cooling chamber such that it is in simultaneous fluid communication with the plurality burster tubes. A liquefied energetic mixture—which may be a polymeric suspension—is flowed onto the distribution fixture from which it is delivered simultaneously and continuously to each of the burster tubes. As the tubes fill with the liquefied mix, any air trapped within the tubes is vented via the weep holes. Depending upon the mix and its properties, coolant may be circulated within the cooling chamber such that the energetic mix is selectively cooled and solidified at various levels of the tubes. In this manner, a uniform solid energetic mix is formed within each of the burster tubes.
A more complete understanding of the present disclosure may be realized by reference to the accompanying drawings in which:
The following merely illustrates the principles of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its spirit and scope.
Furthermore, all examples and conditional language recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions.
Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently-known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
Thus, for example, it will be appreciated by those skilled in the art that the diagrams herein represent conceptual views of illustrative structures embodying the principles of the disclosure.
With reference now to
As those skilled in the art will readily appreciate and understand, burster tubes 150 such as those shown in
While not specifically shown in the figure—and in no way limiting to the present disclosure—the energetic mixture may comprise the known composition B-5 which comprises 63% RDX, 34% TNT, 1% Glyceride, and 2% liquid urethane. As may be appreciated by those skilled in the art, completely filling the burster tube 150 with a mixture 151 such as B-5 is extremely difficult since a suspension is formed and this suspension tends to separate during loading into the tube 150. Additionally, since such energetic mixtures are polymeric, they cure/solidify and therefore it is necessary that the rate/amount of solidification be controlled such that burster tubes exhibiting desirable fill characteristics are produced. Particularly problematic with prior art methods is the entrapment of air within the solidified energetic mix 151.
As those skilled in the art will further appreciate, structures and methods according to the present disclosure permit the filling of burster tubes (for example, the ones shown in
With continued reference to
Shown further in that
When burster tubes are positioned in the loading assembly, the bottoms fit snugly over portions of the receiving fixtures 160. Each fixture has a weep hole 165 that allows any air trapped by the inflowing energetic mix to escape before the energetic mix solidifies. As may be readily understood, this helps to prevent large cavities from forming at the base of the filled burster tubes.
Shown further in
At this point those skilled in the art will understand that while we have used the term “coolant” to describe the material and processes employed during and after loading, our disclosure is not so limited to cooling. For example, particular energetic mixtures may require or benefit from the pre-heating of the burster tube before/during filling. In such circumstances, the “coolant” may be heated and circulated within the cooling vessel 120 thereby pre-heating the burster tubes 150 prior to their loading. Such an operation may advantageously promote the liquidity of the energetic mix and enhance its flow into the tubes.
Continuing with this discussion of pre-heating, it is noted that the distribution fixture 110 preferably includes a chamber(s) 113 through which heated coolant may be circulated via ports 112, 114. In this manner, the distribution fixture 110 may likewise be pre-heated through the effect of the circulation of heated coolant through the chamber such that the energetic mix maintains sufficient liquidity to be distributed to the burster tubes via the distribution channels 115.
Turning now to
At this point, while we have discussed and described the burster tube loading assembly it is noted that the assembly may be fabricated from a single or a number of materials as appropriate. For example, in a preferred embodiment stainless steel(s) and/or aluminum may be employed depending upon the materials and temperatures employed while filling the burster tubes. The receiving fixtures may be fabricated from Teflon or other materials which provide suitable chemical properties.
Operationally, burster tubes are positioned into a respective receiving fixture positioned at the bottom of the cooling chamber. As described previously and shown in the drawing, an individual burster tube is inserted into the receiving fixture and sufficiently sealed such that when the liquefied energetic mix is flowed into the tube, no undesirable leakage occurs. As may be appreciated, when a particularly tight seal is required o-rings or other known sealing structures may be employed within the retaining fixture(s) as necessary. As shown in the figures, a preferred embodiment of the positioning of the receiving fixtures is that they are radially positioned along the bottom of the cooling chamber.
Once the burster tubes are so positioned, the distribution fixtures is secured to the top of the cooling chamber. The distribution fixture includes a number of distribution conduits and these conduits are aligned with and engage the top portion of the burster tubes. In the exemplary embodiments shown and described, there are 18 distribution conduits formed in the distribution fixture although those skilled in the art will appreciate that a greater or lesser number of conduits may be fabricated as desired and/or required.
Accordingly, a liquefied mix—for example B-5 described previously, is poured or otherwise applied to the top of the distribution fixture where it is distributed via distribution channels to the distribution conduits and into the burster tubes. As noted previously, a pre-heated coolant may be circulated through an inner chamber of the distribution fixture such that it maintains a temperature suitable to maintain a desirable liquid characteristic of the energetic mix.
As the liquid energetic mix flows down into the burster tubes, trapped air is vented through the weep holes such that a uniform mix is loaded into the tubes. As the tubes fill with energetic mix, a coolant may be circulated through the cooling cylinder. By selectively controlling the coolant level through the use of the ports on the side of the cooling cylinder, the height of the cooling liquid (preferably water) may be controlled such that portions of the burster tubes are filled and cooled prior to later (higher) portions. In this manner, a uniform energetic mix is controllably filled and solidified in the burster tubes thereby ensuring uniformity in performance.
The inventions described herein may be manufactured, used and licensed by or for the U.S. Government for U.S. Government purposes.
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