Patent Application
20100276544
1. Technical Field of the Invention
The invention is in the field of separation systems for separating subvehicles from missiles or spacecraft.
2. Description of the Related Art
Various systems have been used to separate subvehicles from a missile or spacecraft during flight. Among the mechanisms utilized in such systems have been all lock mechanisms, springs, inflatable bladders, severable clamping straps, and rotation of all or parts of the missile or spacecraft. Shortcomings of these methods have included undesirable heaviness, complexity, and large shock loads to the subvehicles, as well as difficulty in integrating with other systems. Therefore it would be advantageous to have improvements in this area.
A separation mechanism for separating subvehicles from a spacecraft or missile includes an integrated mechanism for disconnecting, releasing, and ejecting said subvehicles. The unified or integrated mechanism reduces weight and shock loads, relative to prior systems with separate mechanisms for disconnecting electrical, fiber optic, and/or cryo lines, releasing the subsystem, and ejecting it to a desired velocity. Each subvehicle may have a single pyrotechnic device or other gas-generating device that moves a cutter to sever cryogenic lines and mechanical coupling, and also activates a piston to push the subvehicle away from the main missile body. By using a single pyrotechnic device or other gas generating device to separate a subvehicle from the main missile body, as well as sever cryogenic lines coupling the two, shocks on the subvehicle are reduced. This leads to improved performance. In addition, the system may eject a subvehicle in a direction substantially perpendicular to an axis of the subvehicle and/or substantially perpendicular to an axis of the main missile body, leading to an improved spacing of the subvehicles. For example, the subvehicles may be spaced on a wider footprint than for prior systems.
According to an aspect of the invention, a separation system includes a single integrated device that both mechanically decouples a subvehicle from a main body, and detaches cryogenic lines running between the subvehicle and the main body.
According to another aspect of the invention, a single separation system provides full separation between a subvehicle and a main body with a reduced number of shocks, for instance no more than two shocks. One of the shocks may occur from activating a pyrotechnic or other gas-generating system, and the other shock may occur from severing or otherwise decoupling substantially all the connections between a subvehicle and a main body.
According to yet another aspect of the invention, a separation system for separating subvehicles from a missile body may include a pyrotechnic device that uses pressurized gas to sever a mechanical connection between the subvehicle and the main body, and to extend a piston to provide a force to push the subvehicle away from the main missile body.
According to still another aspect of the invention, a separation system for separating a subvehicle from a main body includes a pressure-driven cutter for severing, cleaving, or otherwise separating a mechanical connecting member and/or other structures between the subvehicle and the main body. The mechanical connecting member may be a solid or hollow retention rod that initially mechanically couples the main body and the subvehicle together.
According to a further aspect of the invention, a missile includes: a missile main body; one or more subvehicles initially mechanically coupled to the main body; cryogenic lines connecting the missile main body and the subvehicles; and a separation system that enables selective decoupling during flight of the one or more subvehicles from the main body. The separation system includes one or more pressurized gas sources that use pressurized gas both to mechanically decouple the one or more subvehicles from the missile main body and to disconnect the lines from the missile main body and eject the subsystem at a desired velocity.
According to a still further aspect of the invention, a missile includes: a missile main body; one or more subvehicles initially coupled to the main body; and a separation system that enables selective decoupling, during flight, of the subvehicles from the main body. The separation system includes one or more pressure-driven cutters for severing mechanical couplings between the subvehicles and the main body.
According to another aspect of the invention, a missile includes: a missile main body; multiple subvehicles initially coupled to the main body; and a separation system that enables selective decoupling during flight of the subvehicles from the main body. The separation system includes a single pressurized gas source that provides a single shock in the process of separating the subvehicles.
According to yet another aspect of the invention, a method of separating subvehicles of a missile from a missile main body includes the steps of: disconnecting cryogenic lines connecting the missile main body and the subvehicles, using pressurized gas from one or more pressurized gas sources; and mechanically decoupling and separating the subvehicles from the missile main body, using the pressurized gas.
According to an embodiment of the invention, aspects described above and below may have one or more of the following features: a separation system includes a single pressurized gas source or pyrotechnic gas generator for decoupling and separating all of the subvehicles; alternatively, each of the subvehicles is separated by a different pressure source; a separation system uses a piston, driven by pressurized gas, to push a subvehicle away from a main missile body; the piston moves within a space between a piston cylinder and a piston sleeve; a piston vent is used to communicate pressurized gasses, to move the piston; the piston presses against a fitting on the subvehicle; the actuation of the separation is caused by severing a retention rod with a cutter or actuating a ball lock or segment lock, or releasing any locking system, using the same pressurized gases that move the piston to cause separation; the piston is retained with the missile main body after separation; the piston may have multiple segments, which may initially be stacked or nested within each other, and which may move relative to one another under influence of the pressurized gases, to expand the piston and push away the subvehicle; the subvehicle may have a fitting which fits inside the piston; this fitting may have ramped surfaces on a protruding lip, which urge balls into a piston groove on an inner surface of the piston; a cutter may be driven by pressurized gas to sever a retention rod and/or cryogenic lines; the cutter may have a concave cutting surface; the retention rod may have a notched surface; the notched surface may have a V shape, or a scalloped shape, for example having a semicircular cross-section; a pressurized gas source, such a pyrotechnic device, is detonated, producing pressurized gases that drive a cutter that severs or otherwise disconnects a mechanical coupling (for example including a retention rod) and/or cryogenic lines, the pressurized gases also move a piston to push a subvehicle away from a main missile body, with the piston for example pushing on a piston of the subvehicle; a piston may extend perpendicular to an eject direction, in conjunction with a lever to transfer the piston extension direction to a desired ejection direction (this allows more compact packaging of the piston next to the subvehicle); a passive cryogenic line disconnect (the line simply pulls away from the ejection); an actuated cryogenic line disconnect (by use of a pressure source); a passive connector disconnect for electrical connectors, fiber optic connectors, etc.; an actuated connector disconnect (using pressure source to actuate disconnection).
To the accomplishment of the foregoing and related ends, the invention comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
In the annexed drawings, which are not necessarily to scale:
A missile includes several subvehicles that are initially mechanically coupled to a missile main body, and a separation system for separating the subvehicles form the missile main body. The separation system has a single triggering mechanism to simultaneously provide energy to separate all of the subvehicles. This advantageously provides only a single shock to the system by actuating the system to separate the subvehicles. By limiting the shocks to the single shock of actuating the energy system and the shocks of the mechanical disengagement of the individual subvehicles, the disengagement system has improved performance. The mechanical coupling between the subvehicles and the main body may be provided by retentions rods that are severed during the separation process. The severing of the retention rods may be accomplished at the same time as the severing of cryogenic lines linking the main body and subvehicles. The subvehicles may be separated from the main body in radial directions substantially perpendicular to a central axis of the main body. This may provide for smoother disengagement, with less tipping, and may provide for greater, more uniform spacing between the disengaged subvehicles.
Referring initially to
The main body 12 has a number of subvehicles 14 initially within it and initially mechanically and operatively coupled to the main body 12. A separation system 16 is used for selectively separating the subvehicles 14 from the main body 12. The subvehicles 14 may be separated to increase chances of intercepting a target, such as an enemy missile or projectile.
The missile 10 may be a space vehicle, used for intercepting targets at a high altitude or in space. The subvehicles 14 may be initially coupled to the main body 12 by electrical connections and cryogenic lines. The cryogenic lines may be used to cool systems in the subvehicle 14, such as optical systems including seekers for acquiring targets and guiding the subvehicles 14 to one or more targets.
Various configurations of the separation system 16 are described below. The separation system 16 mechanically decouples the subvehicles 14 from the missile main body 12. In addition the separation system 16 must disconnect electrical connections and cryogenic line connections between the subvehicles 14 and the missile main body 12. In doing so it is desirable to minimize the number and magnitude of shocks (brief surges in force) on the subvehicles 14. Further, it is desirable to separate the subvehicles 14 in a smooth manner that maintains their general orientation, without undue tipping or other changes in direction in the subvehicles 14, and it is desirable for the subvehicles 14 to be evenly dispersed over a desired area.
The pressurized gas sources 34 and 36 may be any of a variety of suitable sources. Examples include pyrotechnic charges used as a gas generator, and a pressure vessel such as a cryogenic bottle that has pressurized gas in it.
The retention mechanism 40 includes a retention rod 50 that mechanically couples the subvehicle 14 to the main missile body 12. One end the retention rod 50 is secured to a cutter housing 52 that in turn is secured to an ejection mechanism support 56 of the main missile body 12. At the opposite end the retention rod 50 has a flange 60 that is secured within a bracket 62 of the subvehicle 14. The retention rod 50 has a central cryogenic line pass-through hole 66. The hole 66 allows cryogenic lines to pass through the retention rod 50 for coupling a cryogenic system of the main missile body 12 to devices in the subvehicle 14 that require cryogenic temperatures.
As will be explained in greater detail below, the retention rod 50 and the cryogenic lines may be severed by a cutter 70 that is driven into and through the retention rod 50 by detonation of a pyrotechnic device or system 72, an example of a pressurized gas source. The pyrotechnic device 72 also provides pressurized gas for operation of the ejection mechanism 46. An anvil 76 provides a stop for the cutter 70.
The ejection mechanism 46 includes an eject piston 78 that is between a piston cylinder 80 and a piston sleeve 82. The piston sleeve 82 surrounds the retention rod 50, and allows a portion of the rod 50 to slide relative to the sleeve 82 as the submunition 14 is separated in the missile main body 12. A piston vent 86 in the cutter housing 52 provides a conduit for introducing pressurized gases from the pyrotechnic system 72 into the space between the piston cylinder 80 and the piston sleeve 82. The pressurized gases are used to move the ejection piston 78 to push the subvehicle 14 off of the subvehicle support 42 and away from the main missile body 12.
The retention rod 50 may be oriented radially relative to the subvehicle 14. That is, the retention rod 50 may have its axis perpendicular to a subvehicle axis 90. In addition the retention rod 50 may be substantially perpendicular to an axis of the main missile body 12. Preload stress may be provided on the retention rod 50 in order to reduce the amount of force from the cutter 70 that is required to sever the retention rod 50. The preload stress may be by suitable torquing of a fastener during assembly.
After firing of the pyrotechnic device 172 the retaining rod 150 is severed, as shown in
The subvehicle 14 continues to move away from the main missile 12, as illustrated in
The system 216 has a pair of holes 280 and 282 in the cutter 270. Respective cryogenic lines 284 and 286 pass through the holes 280 and 282. Following of the pyrotechnic charge 272 causes rapid acceleration of the cutter 270 toward the retention rod 250. This shears off the portions of the cryogenic lines 284 and 286 that are in the holes 280 and 282. Thus, movement of the cutter 270 severs the cryogenic lines 284 and 286, which operate as shear pins.
The retention rod 250 has a notch or scoring 290 around its circumference. This reduced-thickness portion provides a preferential rotation for severing of the retention rod 250. The notch or scoring 290 may have any of a variety of configurations, for example being a scalloped notch or a V-shape notch.
The cutter 270 may have a concave surface 294 for impacting the retention rod 250. The concave surface 294 may advantageously minimize the impact area with the retention rod 250. It will be appreciated that the cutter 270 may have a variety of other tip shapes, such as blunt shapes or sharp shapes, in addition to the various specific shapes shown in other embodiments.
The cutter 270 may be made of steel. Material may be omitted from a slot or passage 296 in the cutter 270, in order to reduce weight of the cutter 270.
Various parts of the separation systems described herein may be made of suitable materials, such as steel. Alternate materials include titanium, INCONEL alloys, advanced ceramics, and corrosion resistant steel (CRES), or any mix of these high strength materials. For instance, the housing can be made of titanium to reduce weight since it is the largest component and the system is to be used on spacecraft, where weight optimization may be important. The cutter and retainer rod could remain steel or CRES (such as 17-4 stainless steel). Though to avoid any galvanic corrosion issues, it may be advantageous to minimize differing materials that may develop into a galvanic couple. It should be appreciated that the various features of the various embodiments disclosed herein may be combined in a single device, where possible.
It will be appreciated that many further variations are possible. The ejection mechanisms described herein by be used to eject miniaturized spacecraft or other subvehicles radially mounted to a central structure. The spacecraft or other subvehicles may be ejected or separated from the central structure at different velocities, at different times, or in different subgroupings. The pyrotechnic and other devices used for ejection may be sized or otherwise configured to release a single subvehicle or subset of the total number of space craft or other subvehicles at different ejection speeds. This would have the advantage of avoid collisions between spacecraft or other subvehicles during the ejection process, as well as potentially increasing are coverage of the ejected spacecraft or other subvehicles. Spreading of the spacecraft or other subvehicles may also be accomplished by temporally spacing the ejections in a desire sequence, with some ejections coming after others, for example with some pyrotechnic devices being fired only after one or more spacecraft or other subvehicles have been separated from the central structure.
Another variant is that the disengagement mechanisms described above as being part of a central structure (or missile main body) may instead be parts of the subvehicles that are separated from the main body. For example the pressurized gas sources and cutters may be parts of the subvehicles, rather than the missile main body. Use of a pressure source, such as a liquid divert and attitude control system (LDACS), from the subvehicles has the advantage of reducing spacecraft ejection shock loads. The LDACS is primarily used to steer the subvehicles, but may also be used as the pressure source for the ejection or separation system. Such a system is shown schematically in
An additional advantage of the configuration shown in
Another advantage is excess LDACS pressurant gases can be used to further increase subvehicle deployment velocities as a cold gas thruster through the retention rod remnant, to further propel the subvehicles radially away from the main missile body, each at different speeds from the other spacecraft or subvehicles, to create a predetermined interception field for maximum targeting coverage. In this way the LDACS diverts would not have to be ignited at ejection when the spacecrafts are in close proximity to each other. This could reduce or eliminate the possibility of damaging or disabling a number of spacecrafts or subvehicles during initial fly out.
Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
