During a launch, launch systems can damage their payloads or items associated with the payloads, such as cords or tethers that couple the payload to another device, such as a controller. For example, electrical portions of a projectile may be subjected to an unacceptable level of vibratory shock during launch. This vibratory shock can dislodge electrical components or otherwise damage them. In another example, a tether that is connected to the payload can be damaged during launch. Better control of launch apparatus, systems and methods is needed to reduce instances of damage to projectiles that are launched and to reduce instances of damage to devices associated with those projectiles, such as tethers.
One embodiment of the present subject matter includes a lightweight launch system for launching an unmanned aerial vehicle (“UAV”). The system includes a carbon fiber cylinder of a length extending from a distal portion terminating at an exit opening to a proximal portion terminating at a closed bottom portion. The system also includes a carbon fiber ram sealably disposed in the carbon fiber cylinder, the ram including a plurality of protrusions to maintain the UAV in alignment with the ram while the ram traverses the length of the cylinder, the ram at least partially defining an aperture. The system also includes a cable disposed through the aperture and coupled to the UAV and to electronics disposed outside the cylinder. The system further includes a propellant disposed between the closed bottom portion and the ram, the propellant to force the ram and the UAV out of the cylinder. The system also includes four wedges coupled to the exit opening along an interior of the cylinder, the four wedges to define a modified interior of the vessel at the exit opening that has a reduced interior boundary that is less than a cross section at the closed bottom portion. In, the four wedges are located a distance along the length of the cylinder to maintain slack in the cable from the ram to the closed bottom portion of the vessel after the ram is wedged between at least two of the wedges. Also, the system includes at least one step-shaped stop extending into the interior of the cylinder, the step shape stop further away from the closed bottom portion than the four wedges, the step-shaped stop defining a further modified interior that has a further reduced interior boundary that is less than the cross section. Embodiments are included in which the system is formed of components of a mass less than a specified mass for carry by a single soldier.
The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.
In some embodiments the charge 116 includes an propellant to expand against the ram 108 to force the ram 108 along exit vector 114 and toward the exit opening 106. In some embodiments, the charge 116 includes a gas generator. Some examples include a gas generator such as that used in an automotive airbag. In some embodiments, the gas generator is to blow the ram toward the exit opening 106. The present subject matter includes other kinds of charges to propel the ram 108. For example, some embodiments move the ram 108 by pressurizing gas under the ram 108. In various embodiments, the projectile 118 rests on the ram 108 and departs from the ram 108 and a vessel 102 when the ram 108 encounters one or more ramps or wedges 112 (112 is typical of a plurality) and is slowed or stopped by those one or more wedges 112.
The one or more wedges 112 are coupled to vessel 102 along the vessel interior 103. In various embodiments, the one or more wedges 112 are disposed around the exit opening 106. In various embodiments, the one or more wedges 112 are to wedge the ram 108 in the launch system 100.
The projectile 118 is an ordinance in some embodiments. In some embodiments, the projectile 118 is an unmanned aerial vehicle (“UAV”), but the present subject matter is not so limited. In some embodiments, the launch system 100 is a reusable single-man carryable UAV launching system. In various embodiments, the launch system is formed of components of a mass less than a specified mass for carry by a single soldier, according to a specified specification, such as a military specification.
In some UAV embodiments, the UAV remains connected to terrestrial control electronics via a cord, cable or tether that is disposed at least partially within the launch vessel 102. In some embodiments a fiber optic cable is coupled between a projectile and the launch system 100. In additional embodiments, the UAV remains connected to terrestrial control electronics via a cable, cord or tether that is disposed outside the launch vessel 102. An example cable 302 is illustrated at least partially within a launch vessel 102 in
Embodiments disclosed herein provide one or more structures to slow and stop the travel of the ram 108 as the ram 108 moves along exit vector 114 toward the exit opening 106. Launch system 100 slows the ram 108 as it move along an exit vector 114 toward the exit opening 106 before stopping it. The launch system 100 allows the ram 108 to travel freely before stopping it, imparting less stress onto components that touch the ram 108, such as electronics or a cable, cord or tether. In one example, a cable, cord or tether extends through the ram 108 during the launch, and the cable experiences a lower shock from the ram 108 slowing prior to stop than it does in embodiments in which the travel of ram 108 is freely allowed prior to the ram 108 stopping.
The launch system 100 more reliably maintains the orientation of the ram 108 with respect to the launch vessel 102. If the ram 108 is allowed to move freely along an exit vector 114 before it stops near the exit opening 106, the shock from stopping can be great. This stopping shock can cause the ram 108 to change its orientation in the launch vessel 102. In some instances, the ram 108 rotates around a diameter of the ram 108.
Rotation of the ram 108 around a diameter of the ram 108 is problematic. In embodiments with a cable, cord or tether disposed through the ram 108, such rotation can be damaging to the cord. Such rotations can also damage the launch vessel 102. This is troublesome, as users often want to reuse the launch system 100 to launch multiple projectiles.
Embodiments that do not use one or more wedges 112, but that want to prevent the ram 108 from exiting the launch vessel 102 during launch, use some other structure to decelerate the ram 108, such as a lip 312 extending into the exit opening 106.
The launch vessel 102 is alternatively known as a barrel or tube. The illustrated vessel 102 is cylindrical, but the present subject matter includes embodiments which are another shape. Some cylindrical embodiments have a uniform diameter along their length L, but examples that are not cylindrical are also possible. Non-cylindrical embodiments include rectangular ones and those defining a frustoconical-shaped interior 103. The embodiments illustrated in
The ram 108 is slidably disposed in the launch vessel 102. The ram 108 is shaped to conform to the vessel interior 103 in that the ram 108 has an edge face 111 that confronts an interior face 113 of the vessel 102. In some embodiments this face is linear, and in others it is curvilinear. This confrontation can include an abutting relationship. In an abutting relationship, the edge face 111 is held within a specified tolerance, the interior face 113 is held within a respective specified tolerance, and the space between the edge face 111 and the interior face 113 is selected to allow for slidable disposition of the ram 108 in the vessel 102 with the ram maintaining alignment with the vessel throughout a travel path through the vessel 102 such that a center axis 126 of the ram 108 remains parallel with a center axis 124 of the vessel 102.
In various embodiments, the ram 108 is sealably, slidably disposed in the launch vessel 102. For example, in some embodiments, the ram 108 conforms to the vessel interior 103 such that gas flow from the bottom side 130 of the ram 108 to the top side 128 is restricted during launch of the projectile 118. In some embodiments, a seal 110 is provided to seal the ram 108 to the vessel 102 so that the ram 108 is sealably disposed in the launch vessel 102. The seal 110 can include, but it not limited to, bushings, O-rings, ram rings, and other types of seals used to seal rams.
Various embodiments include one or more wedges 112 coupled to the launch vessel 102. The one or more wedges 112 are coupled using one or more of adhesive, fasteners, welding or another coupling. In some embodiments, the adhesive is blue yellow adhesive. In various embodiments, the one or more wedges 112 are coupled to the launch vessel 102 along the vessel interior 103 proximal the exit opening 106. In various embodiments, the one or more wedges 112 are sized and/or oriented with respect to the launch vessel 102 to increasingly narrow a cross section, such as that pictured in
In various embodiments, the launch vessel 102 is to house a charge 116. In various embodiments, the charge 116 is housed proximal the bottom portion 104. The charge 116 is to propel the ram 108 along the exit vector 114, with the one or more wedges 112 sized to stop the ram 108 inside the vessel interior 103. In various embodiments, the charge 116 generates gas to blow the ram 108 toward the exit opening 106.
Coupled to launch vessels of the present subject matter are one or more wedges. In some embodiments, four wedges 206 (206 is typical) are coupled to the launch vessel 202. In some embodiments, the wedges 206 are distributed equidistant from one another around a circumference of the launch vessel 202.
Various embodiments include a ram 208, optionally formed of carbon fiber. In various embodiments, the ram 208 is sealably disposed in launch vessel 202. The ram 208 optionally includes a plurality of protrusions 210 to maintain a projectile, such as a UAV, in alignment with the ram 208 while the ram 208 traverses the length of the launch vessel 202.
In one option, the ram 208 at least partially defines an aperture 212. In various embodiments, a cable is disposed through the aperture 212. In some embodiments, the cable is coupled to a UAV and to electronics disposed outside the launch vessel 202. An example with a cable 302 is illustrated in
Some embodiments include four wedges 206 (206 is typical) coupled to the exit opening 214 along an interior of the vessel 202. In various embodiments, the four wedges 206 are located a distance along the length to maintain slack in the cable from the ram 208 to the closed bottom portion 216 after the ram 208 is wedged between at least two of the wedges 206. In some examples, the ram 208 is percussion welded to the wedges 206. In various embodiments, the wedges 206 have a slow such that the ram material percussion welds to the ring when propelled by the charge. In some embodiments, the launch system 200 is configured to allow a user to replace the ram 208 and the wedges 206 after each launch.
In various embodiments, the launch system 200 includes at least one lip 218 extending into the interior of the launch vessel 202. In various embodiments, the lip 218 is further away from the closed bottom portion 216 than are one or more of the four wedges 206. In some embodiments, electronics are coupled to the connector 220 to detonate a charge disposed in the bottom portion 216 to propel the ram 208.
Optionally, one or more lips 312 (312 is typical) define a further interior boundary through the C-PLANE. In various embodiments, the one or more lips 312 are step-shaped, but the present subject matter includes other shapes, such as ramps. The further interior boundary defined by the one or more lips 312 is less than the interior boundaries through both the A-PLANE and the B-PLANE. In some embodiments, the materials of the ram 306 and wedges 308 are selected so that one or both of the ram 306 and one or more wedges 308 can deform, either plastically or elastically or both, so that the ram 306 is interference fit between the wedges 308. In various embodiments, the interior boundary through the C-PLANE is sized so that the ram 306 cannot pass through that interior boundary. In various embodiments, the lip 312 is a feature of a collar 314. In various embodiments, the collar 314 is coupled to the launch vessel 304. The collar 314 can be coupled to the launch vessel 304 via adhesive, fasteners or another coupling. In various embodiments, the one or more wedges 308 are coupled to one or both of the collar 314 and the launch vessel 304.
In some embodiments, there are four lips 312. In various embodiments, each has a length S. In some embodiments, the length S is approximately 15 degrees, but the present subject matter is not so limited. In additional embodiments, the lips 312 have different arc lengths. In various embodiments, each of the lips 312 has a length S that spans the same length of a corresponding one or more wedges 308. In some embodiments, S is around 90 degrees. In some of these embodiments, three or fewer wedges 308 are used. In some embodiments, a wedge 308 encircles the entire exit opening 326. In some embodiments, a single lip 312 encircles most of or the entire exit opening 326.
In some embodiments, each lips 312 has an arc length equal to its corresponding one or more wedges 308 and abuts the corresponding one or more wedges 308. In these embodiments, the lip 312 assists in stopping the ram 306 from exiting the launch vessel 304 in addition to resisting movement of the one or more wedges 308 outside of the launch vessel 304, should the fasteners 316 (316 is typical) shear. The lip 312 is part of four step shape stops, each abutting a respective wedge 308, each spanning an arc of the circumference approximately equal to a further arc spanned by a respective wedge 308.
In various embodiments, a projectile is coupled to the barrel with a cable 302 disposed through the ram 306. In various embodiments, the cable 302 is coupled to the bottom portion of the launch vessel 304. In various embodiments, the cable 302 is sized such that when the ram 306 is wedged between at least two of the one or more wedges 308, the cable 302 has slack 318 between the ram 306 and the bottom portion of the launch vessel 304. In various embodiments, a projectile is coupled to the ram 306 using protrusions 330 (330 is typical) to align the projectile to the ram 306.
In various embodiments, the cable 302 is disposed through an aperture 320. In various embodiments, the aperture 320 has a top portion that is funnel-shaped. In some embodiments, the interior face 322 of the funnel is linear. In additional embodiments, it is parabolic. In some embodiments, a bottom portion 324 of the aperture 320 is linear. In additional embodiments, it is non-linear. Accordingly, in some embodiments, the aperture 320 is hour-glass shaped. In some embodiments, the shape of the funnel is selected so that the cable 302 is subjected to maximum bend radius proximal the ram 306. In various embodiments, the bend radius is specified to allow the cable 302 to elastically bend. In some embodiments, the aperture 320 is filled with a potting material, such as an adhesive.
In various embodiments, a recess 332 is defined in the launch vessel 304. In various embodiments, the recess 332 is deep enough so a portion of the one or more wedges 308 can fit into it. In various embodiments, the recess 332 is deep enough so there is a smooth transition from an inside face 334 of the launch vessel 304 to a ramp surface 328. The ramp surface 328 faces the interior 310. In some embodiments, the one or more wedges 308 do not fully fill the recess 332, leaving a space 336. In other embodiments, the one or more wedges 308 fill the recess 332.
In the present description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims.
The Abstract is provided to comply with 37 C.F.R. Section 1.72(b) requiring an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.
Number | Date | Country | Kind |
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12417418 | Apr 2009 | US | national |
This application claims the benefit of U.S. application Ser. No. 12/417,418, filed Apr. 2, 2009, the disclosure of which is incorporated herein by reference in its entirety.
This invention was made with United States Government support under Contract number NBCHC040160 with the Department of the Interior. The United States Government has certain rights in this invention.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/00966 | 3/31/2010 | WO | 00 | 11/26/2012 |