Integrated Pusher Plate for a Canister- or Gun-Launched Projectile and System Incorporating Same
A pusher plate assembly for launching a projectile includes a pusher plate, a pressure seal circumferentially extending about the pusher plate, a cage extending from an aft side of the pusher plate, and a plurality of propellant portions disposed in the cage. A projectile system includes a launching tube, a projectile disposed in the launching tube, a pusher plate assembly disposed between an aft end of the projectile and the launching tube, a fuze, a charge igniter operatively associated with the fuze and the plurality of propellant portions, and a retainer disposed within the launching tube proximate a mouth of the launching tube. The pusher plate assembly includes a pusher plate, a pressure seal circumferentially extending about the pusher plate to seal an annulus between the pusher plate and the launching tube, a cage extending from an aft side of the pusher plate, and a plurality of propellant portions disposed in the cage.
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1. Field of the Invention
The present invention relates to projectile launching systems.
2. Description of Related Art
Many modern projectiles, such as missiles, rockets, and the like, are launched from canisters or guns. In some projectile systems, thrust from a projectile's motor is used to launch the projectile from a canister or gun. Using the projectile's thrust to launch the projectile, however, reduces the amount of propellant available to propel the projectile to its intended target.
In response to this problem, some projectile systems employ a launching propellant, which is separate from the projectile's propellant, to launch the projectile from the canister or gun and to provide an initial velocity to the projectile. For example,
It is desirable, however, for canister 105 to be as small as possible to minimize the size of the overall projectile system and to minimize cost. However, as shown in
To overcome this problem, as shown in
There are many designs of projectile launching systems well known in the art, however, considerable shortcomings remain.
The novel features believed characteristic of the invention are set forth in the appended claims. However, the invention itself, as well as, a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, in which the leftmost significant digit(s) in the reference numerals denote(s) the first figure in which the respective reference numerals appear, wherein:
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTIllustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
A pusher plate assembly for launching a projectile includes a pusher plate, a pressure seal circumferentially extending about the pusher plate, a cage extending from an aft side of the pusher plate, and a plurality of propellant portions disposed in the cage.
A projectile system includes a launching tube, a projectile disposed in the launching tube, a pusher plate assembly disposed between an aft end of the projectile and the launching tube, a fuze, a charge igniter operatively associated with the fuze and the plurality of propellant portions, and a retainer disposed within the launching tube proximate a mouth of the launching tube. The pusher plate assembly includes a pusher plate, a pressure seal circumferentially extending about the pusher plate to seal an annulus between the pusher plate and the launching tube, a cage extending from an aft side of the pusher plate, and a plurality of propellant portions disposed in the cage.
A method for launching a projectile from a launch tube includes providing a pusher plate assembly disposed between the projectile and the launch tube. The pressure plate assembly includes a pusher plate, a pressure seal circumferentially extending about the pusher plate to seal an annulus between the pusher plate and the launching tube, a cage extending from an aft side of the pusher plate, and a plurality of propellant portions disposed in the cage. The method further includes igniting the plurality of propellant portions, burning an opening in the cage with the ignited plurality of propellant portions, urging the projectile with expanding gases produced by the ignited plurality of propellant portions, and allowing a progressively larger fraction of the plurality of propellant portions to escape the cage as the pressure plate assembly traverses within the launch tube.
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It should be noted that the burning surface area of the plurality of propellant portions 607, and thus the burn rate of the plurality of propellant portions 607, increases in relationship to the fraction of the plurality of propellant portions 607 that escape cage 605. Generally, chamber 519 increases in volume as a larger fraction of the plurality of propellant portions 607 escapes cage 605. This relationship provides a flatter acceleration curve for projectile 501 than that shown in
Referring now to
Retainer 513 is fixedly disposed proximate a mouth 521 of launching tube 505. Pusher plate 601, pressure seal 603, the remaining portion of cage 605, and any portion of the plurality of propellant portions 607 remaining in cage 605 are captured within launching tube 505 by retainer 513 as projectile 503 exits launching tube 505, thus inhibiting damage to equipment and personnel about projectile system 501.
Advantages of the invention include, but are not limited to (1) providing a means for launching a projectile from a launching tube that manages the acceleration of the projectile without increasing the size of the launching tube; (2) providing a means for launching a projectile from a launching tube without requiring a high axial acceleration tolerance of the projectile; and (3) providing a means for launching a projectile that further includes a means for igniting a motor of the projectile.
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below. It is apparent that an invention with significant advantages has been described and illustrated. Although the present invention is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof.
Claims
1. A pusher plate assembly for launching a projectile, comprising:
- a pusher plate;
- a pressure seal circumferentially extending about the pusher plate;
- a cage extending from an aft side of the pusher plate; and
- a plurality of propellant portions disposed in the cage.
2. The pusher plate assembly, according to claim 1, wherein the cage is formed of wire mesh.
3. The pusher plate assembly, according to claim 1, wherein the pressure seal comprises:
- an elastomer.
4. The pusher plate assembly, according to claim 1, wherein at least some of the plurality of propellant portions comprises one or more of a nitrate-based solid propellant and an aluminum-based solid propellant.
5. The pusher plate assembly, according to claim 1, further comprising:
- a projectile motor igniter; and
- a motor igniter controller operatively associated with the projectile motor igniter.
6. The pusher plate assembly, according to claim 5, wherein the motor igniter controller includes an accelerometer.
7. The pusher plate assembly, according to claim 5, wherein the motor igniter controller includes a position sensor.
8. The pusher plate assembly, according to claim 5, wherein the motor igniter controller includes a timer.
9. A projectile system, comprising:
- a launching tube;
- a projectile disposed in the launching tube;
- a pusher plate assembly disposed between an aft end of the projectile and the launching tube, the pusher plate assembly comprising: a pusher plate; a pressure seal circumferentially extending about the pusher plate to seal an annulus between the pusher plate and the launching tube; a cage extending from an aft side of the pusher plate; and a plurality of propellant portions disposed in the cage;
- a fuze;
- a charge igniter operatively associated with the fuze and the plurality of propellant portions; and
- a retainer disposed within the launching tube proximate a mouth of the launching tube.
10. The projectile system, according to claim 9, wherein the cage is formed of wire mesh.
11. The pusher plate assembly, according to claim 9, wherein the pressure seal comprises:
- an elastomer.
12. The pusher plate assembly, according to claim 9, wherein at least some of the plurality of propellant portions comprises one or more of a nitrate-based solid propellant and an aluminum-based solid propellant.
13. The pusher plate assembly, according to claim 9, further comprising:
- a projectile motor igniter; and
- a motor igniter controller operatively associated with the projectile motor igniter.
14. The pusher plate assembly, according to claim 13, wherein the motor igniter controller includes an accelerometer.
15. The pusher plate assembly, according to claim 13, wherein the motor igniter controller includes a position sensor.
16. The pusher plate assembly, according to claim 13, wherein the motor igniter controller includes a timer.
17. A method for launching a projectile from a launch tube, comprising:
- providing a pusher plate assembly disposed between the projectile and the launch tube, the pressure plate assembly comprising: a pusher plate; a pressure seal circumferentially extending about the pusher plate to seal an annulus between the pusher plate and the launching tube; a cage extending from an aft side of the pusher plate; and a plurality of propellant portions disposed in the cage; igniting the plurality of propellant portions;
- burning an opening in the cage with the ignited plurality of propellant portions;
- urging the projectile with expanding gases produced by the ignited plurality of propellant portions; and
- allowing a progressively larger fraction of the plurality of propellant portions to escape the cage as the pressure plate assembly traverses within the launch tube.
18. The method, according to claim 17, further comprising:
- igniting a motor of the projectile with a projectile motor igniter of the pusher plate assembly.
19. The method, according to claim 18, further comprising:
- operating the projectile motor igniter based on at least one of an acceleration of the pusher plate assembly, a position of the pusher plate assembly with respect to the launching tube, and an elapsed time from ignition of the plurality of propellant portions.
Type: Application
Filed: Jun 11, 2008
Publication Date: Dec 17, 2009
Applicant: LOCKHEED MARTIN CORPORATION (Dallas, TX)
Inventors: Wayne K. Schroeder (Mansfield, TX), Umang R. Patel (Mansfield, TX), Johnny E. Banks (Venus, TX)
Application Number: 12/137,187
International Classification: F42B 5/26 (20060101); F42C 19/08 (20060101);