1. Field of the Invention
This invention relates to submarine countermeasure vehicles and launchers and is directed more particularly to a countermeasure and launch assembly which alleviates problems developed in launching by translation or tilting of the countermeasure vehicle in the launch tube.
2. Description of the Prior Art
In
In operation, the gas generator 34 is activated by an electrical pulse from the submarine fire control system and generates sufficient gas pressure to move the ram plate 32 forwardly. The ram plate 32 pushes the countermeasure vehicle 24 forwardly, breaking away the forward tube cover 36 and launching the countermeasure vehicle 24 from the launch tube 22. In due course, the sabot 30 disengages from around the array assembly 26 and the array assembly is deployed.
It has been found that upon launch of the countermeasure vehicle 24, the fleet vehicle design is sometimes subjected to substantial bending moments when most of the cylindrical vehicle, but not the cylindrical tailcone assembly 28, has exited the launch tube. This occurs from cross flow on the vehicle hull from launching perpendicular to the submarine hull flow. This results in the vehicle 24 being moved sideways in the tube 22, and/or being tilted in the tube as the launch progresses. This may result in potentially asymmetrical axial loading of the ram plate 32 which could jam the ram plate 32 intermittently during launch. Any of these conditions can compromise the launch and the resulting deployment. It may also catastrophically result in complete failure of the tailcone assembly 28 forward hull joint and/or the local aft zone of the vehicle 24 hull structure thereby destroying or critically damaging the vehicle.
Accordingly, there is a need for an improved vehicle and launch assembly which can accommodate severe bending moments and complete a launch under such conditions satisfactorily.
An object of the invention is, therefore, to provide an improved vehicle and launch assembly facilitating launches of the vehicle in severe environments which cause translation and/or tilting of the vehicle in the launch tube.
With the above and other objects in view, as will hereinafter appear, a feature of the present invention is the provision of a submarine countermeasure vehicle and launch assembly therefor. The vehicle comprises a forward end portion, an aft end portion provided with a propeller and fins extending therefrom, a hull portion extending between the forward end portion and the aft end portion, the hull portion being substantially circular in cross-section, and a thrust ring mounted on aft portions of the fins and around the propeller, the thrust ring forming a convex configuration. The launch assembly comprises a launch tube for retaining and launching the vehicle, and a ram plate moveable in the launch tube to push the vehicle out an end of the launch tube, the ram plate having an engagement surface for contact with the thrust ring, the engagement surface being at least in part of a concave configuration. In a launch operation, the concave surface of the ram plate engages the convex configuration of the thrust ring.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular device embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
Reference is made to the accompanying drawings in which is shown an illustrative embodiment of the invention, from which its novel features and advantages will be apparent, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein:
Referring to
The launch assembly includes the launch tube 22 and ram plate 32, the latter provided with a concave surface 42 for engagement with the tail cone assembly aft end convex structure 40.
The tailcone assembly 28 includes fins 44 disposed around a propeller 46 and to which is fixed a thrust ring 48. The thrust ring 48 includes a collar portion 50 and hydrodynamically configured radial struts 52 which define the aforesaid tailcone assembly aft end convex configuration. Tailcone assembly 28 and fins 44 can be tapered to avoid contact between tailcone 28 and tube 22 during launch. This will minimize moment loading in the aft structure and joints of the vehicle 24.
When the vehicle 24 rests in the launch tube 22, the surfaces 40 and 42 are in engagement with each other. As noted above, upon initiation of a launch, the ram plate 32 pushes the vehicle 24 at a high rate of speed and ejects the vehicle 24 from the launch tube 22.
To assist in maintaining the vehicle 24 contained within the launch tube 22, the vehicle 24 is conventionally provided with elastomeric pads 54 temporarily bonded to vehicle 24 (
It has been found that providing the concave engagement surface 42 on the ram plate 32 and the convex configuration 40 on the tail cone thrust ring 48, results in the center of thrust being displaced from center only slightly, such that the vehicle 24 is thrust in a direction axial of the launch tube, and jamming of the vehicle 24 in the tube 22 is substantially less likely to occur under even the worst of ambient conditions.
It has further been found that an appropriate radius of curvature a for the convex configurations of the thrust ring 48 is about 6.25 inches, and that a preferred radius of curvature b for the ram plate engagement surface 42 is twice the radius of curvature a, or about 12.5 inches. Alternative radii of curvature for the ram plate engagement surface 42 are 9.75 inches, shown at c in
Referring to
Thus, the ram plate concave surface 42 and the tail cone aft end convex configuration 40 allow the tailcone 28 to slide on the ram plate surface 42 and maintain the thrust vector substantially in the center of the ram plate, which in turn minimizes the possibility of jamming and high bending moments during a launch in a severe environment.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principles and scope of the invention as expressed in the appended claims.
The invention described herein may be manufactured and used by and for the Government of the United States of America for Governmental purposes without the payment of any royalties thereon or therefor.
Number | Name | Date | Kind |
---|---|---|---|
3754725 | Kartzmark et al. | Aug 1973 | A |
5333570 | DuBois et al. | Aug 1994 | A |
5396855 | Dubois et al. | Mar 1995 | A |
5495819 | Marion | Mar 1996 | A |
5737962 | Turner et al. | Apr 1998 | A |
5771741 | Roy et al. | Jun 1998 | A |
6559370 | Barker | May 2003 | B1 |
6568309 | MacLeod | May 2003 | B1 |