Noise abatement system for a gun

ABSTRACT

A noise abatement apparatus for a gun having a gun tube includes a plurality of generally spherical pressure vessels, with a first pressure vessel having an end adapted to be coupled to the gun tube. The pressure vessels are adapted for attenuating pressure waves caused by a firing of a projectile by the gun and for being mounted on a surface. At least two of the pressure vessels are in general alignment with one another. The apparatus may further include at least one connecting portion, a catcher for entrapping particulates and for permitting the projectile to pass, and at least one orifice plate or baffle for aiding in attenuating the sound. A noise abatement system includes the apparatus and a platform on which the apparatus is mounted. The system may further include an actuator for moving the apparatus along a track that is in physical communication with the platform.

INFORMATION

DETAILED DESCRIPTION OF THE INVENTION

This application is the U.S. National Phase application of International Application No. PCT/US02/12133, which claims priority of U.S. Provisional Application No. 60/285,220 filed Apr. 19, 2001.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, an embodiment of a noise abatement apparatus includes a plurality of pressure vessels, preferably three pressure vessels , , , which are preferably substantially spherical in shape and in alignment with one another. Preferably, the noise abatement apparatus comprises three spherical pressure vessels , , that are of decreasing size from the entry end of the projectile to the exit end of the projectile. The apparatus also includes legs , , for mounting each of the pressure vessels , , on a platform .

The noise abatement apparatus can be adapted and sized for a number of different guns . In one embodiment, namely, when the noise abatement apparatus is 3 meters in length and weighs approximately 685 kg, the noise abatement system may be used for 25, 35, and 40 mm guns. For such guns, it has been found that the muffler attenuation of a minimum of 12 dBA at a distance of 250 meters all directions from the gun can be achieved. The material of the pressure values may be any known material for this purpose but is preferably carbon steel .

In a preferred embodiment of the apparatus , the first two pressure vessels , (“first” referring to closer to the entry end of the projectile) have internal orifices/baffles, such as those described in U.S. Pat. No. 5,398,589 or U.S. Pat. No. 5,686,688, both of which are incorporated herein by reference. As an example of the internal orifices/baffles, an orifice plate (not shown) may be at about the center of the first pressure vessel which is coupled to the second pressure vessel . The orifice plate is an annular disk defining a central circular hole through which the projectile passes. The size of the hole is dictated by the size of the projectile. Also, if the hole is too small, it is difficult to rapidly vent the chamber of the first pressure vessel (or of the second pressure vessel ) through the hole and out through the port by way of the exhaust blower. On the other hand, if the hole of the orifice plate is too large, the muffling of sound is not sufficient.

As another example of the internal orifices/baffles, the baffles (not shown) are generally conical in shape, having a diameter which linearly decreases from the entry end of the chamber of the first pressure vessel (or the second pressure vessel ) to the exit end of the chamber of the first pressure vessel (or the second pressure vessel ). Each baffle may abut against the orifice plate. A retaining wall may be coupled to the chamber of the first pressure vessel (or the second pressure vessel ), and each orifice plate may be mounted to the retaining wall by way of straps and nuts and bolts. Similar to the orifice plate of the first example, the orifice plate defines a central hole through which a projectile passes. The diameter of the hole is defined by similar functional requirements as the diameter of the hole of the orifice plate of the first example.

Alternatively, the baffles , , may be those shown in FIGS. 3 and 7, namely, consisting of a steel plate (for baffle ; not shown for baffles , ) with a number of bars (for baffle ; not shown for baffles , ), such as with twelve bars, welded to the plate. These bars serve to improve the diffusion of the gas from the gun . They may either be mounted only to the plate or mounted to the plate at one end and welded to the inside wall of the sphere at their other ends, as shown in FIG. .

According to the present invention, an embodiment of a noise abatement system includes the noise abatement apparatus as described above, as well as a track or tracks mounted on a horizontal concrete pad or slab and an actuator for driving the platform along the tracks .

The pressure vessels , , are mounted on the platform , which as shown consists of an upper steel frame which is attached preferably by a hinge at the entry end to a lower frame . The attachment by the hinge allows for the upper frame to be spaced from the lower frame closer to the exit end of the apparatus . This can be achieved by adjusting elevation adjustment or azimuth adjustment as shown by, for example, screws, a jack system, or a hydraulic mechanism (not shown) or some other means. The lower frame has four legs attached, preferably at its corners, with wheels as shown at the lower end of the legs . The wheels preferably are grooved and can ride on the steel tracks , which itself is attached to the concrete pad or slab embedded in or mounted to the ground. Preferably, the actuator is an electrical actuator, which can be an electric screw jack, may be mounted on the concrete pad or slab and attached to the lower frame to allow for the apparatus to be moved back and forth along the tracks .

The pressure vessels , , can be separated from each other at cylindrical connecting portions , , which can be bolted together. Preferably, the diameter of each of the connecting portions , is greater than the diameter of the gun muzzle . In addition, the pressure vessels , , can be separated from the mounting frame or platform by disconnecting the legs , , from the upper frame , and then completely disassembled by opening them along their halves (as two clam shells) so that they can be easily inspected or repaired, if required. The first pressure vessel incorporates a sabot catcher (namely, a steel plate contoured to the internal wall of the first pressure vessel ) that can be replaced as required by disassembling the first pressure vessel . The first pressure vessel also has an exhaust port with an exhaust blower (not shown) to remove any accumulation of exhaust gas, just as shown and described in U.S. Pat. No. 5,398,589 or U.S. Pat. No. 5,686,688. This can be mounted at any suitable place on the first pressure vessel , typically at the top of the vessel with a vent stack (not shown).

The muzzle of the gun being fired projects into the first pressure vessel that incorporates a seal to prevent any gas blowback, while not creating any frictional drag on the recoil of the gun. The seal may have a configuration as shown and described in U.S. Pat. No. 5,398,589 or U.S. Pat. No. 5,686,688 or any other suitable configuration. For example, the seal may be a sliding seal in the form of a lamination, with each layer of the lamination consisting of a material which is rendered flexible by a plurality of radially extending slots, with the slots offset from one another from layer to layer. Different seals will be utilized for various caliber guns being fired.

The electrical actuator moves the cradle on the rail and positions the muzzle of the gun being fired in engagement with the seal . The muzzle is made accessible for bore siting by moving the cradle to expose the muzzle .

The system and apparatus can be modified by adding any portion or aspect of U.S. Pat. No. 5,398,589 or U.S. Pat. No. 5,686,688 thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed description when read in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of an embodiment of a noise abatement system of the present invention;

FIG. 2 is a cut-away side sectional view, showing a first pressure vessel of a noise abatement apparatus in relation to a gun muzzle of a gun, taken along cut line of FIG. 1;

FIG. 3 is a longitudinal side elevational view of an embodiment of a noise abatement apparatus of the present invention mounted on a platform;

FIG. 4 is a longitudinal side elevational view of the noise abatement apparatus shown in FIG. 3, with at least a portion of the shell of each pressure vessel removed;

FIG. 5 is an end view of the noise abatement apparatus shown in FIG. 4;

FIG. 6 is an enlarged view of an orifice plate or baffle of the noise abatement apparatus shown in FIG. 4; and

FIG. 7 is an enlarged view of a hinge of the platform shown in FIG. .

CLAIMS

1. A noise abatement system for a gun having a gun tube, said system comprising: a platform; and a plurality of generally spherical pressure vessels adapted for attenuating pressure waves caused by a firing of a projectile by the gun and for being mounted on said platform, wherein said plurality of pressure vessels are in general alignment with one another and a first pressure vessel of said plurality of pressure vessels has an end adapted for coupling to the gun tube.

2. The noise abatement system according to claim 1, wherein said platform comprises an upper frame and a lower frame wherein said upper frame is attached to said lower frame by a hinge disposed about said end adapted for coupling to the gun tube.

3. The noise abatement system according to claim 2, further comprising an adjustor for effecting an angular separation between said upper frame and said lower frame about said hinge.

4. The noise abatement system according to claim 2, further comprising a track mounted on a horizontal slab and an actuator for displacing said plurality of pressure vessels along said track, wherein said lower frame comprises a plurality of legs comprising a plurality of wheels adapted for riding on said track.

5. The noise abatement system according to claim 4, wherein said slab is made of concrete.

6. The noise abatement system according to claim 4, wherein said track is made of steel.

7. The noise abatement system according to claim 1, further comprising a track mounted on a horizontal slab and an actuator for displacing said plurality of pressure vessels along said track, wherein said platform comprises a plurality of legs comprising a plurality of wheels adapted for riding on said track.

8. The noise abatement system according to claim 7, wherein said slab is made of concrete.

9. The noise abatement system according to claim 7, wherein said track is made of steel.

10. The noise abatement system according to claim 1, wherein said plurality of pressure vessels is three generally spherical pressure vessels.

11. The noise abatement system according to claim 10, wherein at least two of said three generally spherical pressure vessels are of different sizes.

12. The noise abatement system according to claim 10, wherein said plurality of pressure vessels are of decreasing size in a direction of travel of the projectile.

13. The noise abatement system according to claim 1, wherein said plurality of pressure vessels are mounted on said platform by a plurality of legs.

14. The noise abatement system according to claim 1, wherein said first pressure vessel further has a seal for preventing the escape of residual combustion gases caused by a firing of the projectile by the gun.

15. The noise abatement system according to claim 1, further comprising at least one connecting portion for connecting a pair of said plurality of pressure vessels.

16. The noise abatement system according to claim 1, further comprising a catcher disposed within said plurality of pressure vessels for entrapping particulates and for permitting the projectile to pass.

17. The noise abatement system according to claim 1, further comprising at least one orifice plate being adjustable relative to said plurality of pressure vessels, wherein said orifice plate is disposed in at least one of said plurality of pressure vessels for attenuating pressure waves.

18. The noise abatement system according to claim 17, further comprising a plurality of rods attached to an end of said orifice plate.

19. The noise abatement system according to claim 18, wherein said plurality of rods are further attached to an inside wall of one of said plurality of pressure vessels.

20. A noise abatement apparatus for a gun having a gun tube, said apparatus comprising a plurality of generally spherical pressure vessels adapted for attenuating pressure waves caused by a firing of a projectile by the gun and for being mounted on a surface, wherein at least two of said plurality of pressure vessels are in general alignment with one another and a first pressure vessel of said plurality of pressure vessels has an end adapted for coupling to the gun tube.

21. The noise abatement apparatus according to claim 20, wherein said plurality of pressure vessels is three generally spherical pressure vessels.

22. The noise abatement apparatus according to claim 21, wherein at least two of said three generally spherical pressure vessels are of different sizes.

23. The noise abatement apparatus according to claim 21, wherein said plurality of pressure vessels are of decreasing size in a direction of travel of the projectile.

24. The noise abatement apparatus according to claim 20, wherein said plurality of pressure vessels are mounted on the surface by a plurality of legs.

25. The noise abatement apparatus according to claim 20, further comprising a seal for preventing the escape of residual combustion gases caused by a firing of the projectile by the gun.

26. The noise abatement apparatus according to claim 20, further comprising at least one connecting portion for connecting a pair of said plurality of pressure vessels.

27. The noise abatement apparatus according to claim 20, further comprising a catcher disposed within said plurality of pressure vessels for entrapping particulates and for permitting the projectile to pass.

28. The noise abatement apparatus according to claim 20, further comprising at least one orifice plate being adjustable relative to said plurality of pressure vessels, wherein said orifice plate is disposed in at least one of said plurality of pressure vessels for attenuating pressure waves.

29. The noise abatement apparatus according to claim 28, further comprising a plurality of rods attached to an end of said orifice plate.

30. The noise abatement apparatus according to claim 29, wherein said plurality of rods are further attached to an inside wall of one of said plurality of pressure vessels.

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