This application is the U.S. national phase of international application PCT/ZA2003/000182, filed 8 Dec. 2003, which designated the U.S. and claims priority of ZA 02/10079, filed 12 Dec. 2002, the entire contents of each of which are hereby incorporated by reference.
This invention relates to a gun tube support assembly, a cradle for carrying a gun tube including a gun tube support assembly, and a gun provided with a gun tube support assembly.
A conventional gun tube support assembly for a gun such as a cannon or the like comprises a single solid metal cradle bush or a plurality of solid metal cradle bushes arranged annularly around a gun tube of the gun. The annularly arranged cradle bushes receive and support the gun tube and the gun tube slides therein when the gun is fired.
A first disadvantage of the conventional gun tube support assembly is that when the gun is fired, kinetic energy is transferred from a projectile passing through the gun tube to the cannon structure via the solid cradle bushes to cause metal fatigue and a decrease in the lifespan of the gun.
Further disadvantages of the conventional gun tube support assembly are that the solid metal cradle bushes retains expansion and vibration of the gun tube and thus restrains the projectile when passing through the gun tube and causes excessive structural strains in the projectile, thus having a negative effect on internal and external ballistics. The projectile is further less reliable owing to the vibrations restraining it while passing through the gun tube.
It is therefore an object of the present invention to provide a gun tube support assembly, a cradle for carrying a gun tube including a gun tube support assembly, and a gun provided with a gun tube support assembly with which the aforesaid disadvantages can be overcome or at least minimised.
According to a first aspect of the invention there is provided a gun tube support assembly comprising a plurality of support sections arranged annularly around a gun tube, each including:
The damping means may be a resilient body selected from the group consisting of a rubber pad, a spring, and a pneumatic or hydraulic cushion.
Preferably the damping means comprises a pad of a relatively high-temperature silicon rubber.
The rubber pad may include a plurality of protrusions extending from a face of the pad for accommodating compression of the pad.
Each bush housing may comprise a curved bush housing plate having an inner surface for abutting the resilient body.
End flanges for connecting the bush housing to a cradle of a gun may be disposed towards opposite ends of the bush housing plate.
Removable side flanges for retaining the rubber pad may further be connectable to the sides of the plate.
Each cradle bush may comprise a cradle bush plate curved complementary to the bush housing plate and having an inner surface for abutting the gun tube and an outer surface for abutting the resilient body.
End flanges may extend in the direction of the bush housing from the respective opposite ends of the cradle bush plate.
The protrusions extending from the rubber pad may face towards the gun tube to abut the outer surface of the cradle bush plate.
Preferably, the gun tube support assembly includes from two to six, preferably four support sections arranged annularly around the gun tube and received in an opening in the cradle.
The cradle bush may be biased in the direction of the gun tube to keep the cradle bush in contact with the gun tube and to allow for thermal expansion of the gun tube.
According to a second aspect of the invention there is provided a cradle for carrying a gun tube including a gun tube support assembly according to the first aspect of the invention.
According to a third aspect of the invention there is provided a gun provided with a gun tube support assembly according to the first aspect of the invention.
The invention will now be described further by way of a non-limiting example with reference to the accompanying drawings wherein:
Referring to 1, a gun tube support assembly according to a preferred embodiment of the invention is generally designated by reference numeral 10.
The gun tube support assembly 10 comprises four support sections 12 arranged annularly around a gun tube 13 (shown in
Each support section 12 comprises a bush housing 14 and a cradle bush 16 for the bush housing 14, which receives and supports the gun tube 13. Each support section 12 further comprises a damping means sandwiched between the bush housing 14 and cradle bush 16.
The damping means is in the form of a resilient body, such as a rubber pad 18 made of relatively high-temperature silicon rubber. The rubber pad 18 includes a plurality of protrusions 18.1 extending from a face of the pad 18 for abutting an outer surface of the cradle bush 16. The protrusions 18.1 accommodate compression of the pad 18, the arrangement being such that the rubber pad 18 absorbs and dampens kinetic energy emanating from the gun tube 13 during firing of a projectile (not shown).
Each bush housing 14 comprises a curved bush housing plate 20 having an inner surface for abutting the rubber pad 18. End flanges 22 for connecting the bush housing 14 to the cradle 15 of the gun, by fastening means 24, are disposed towards opposite ends of the bush housing plate 20. Removable side flanges 26 for retaining the rubber pad 18 is further connected to the sides of the bush housing plate 20, by fastening means 28.
Each cradle bush 16 comprises a cradle bush plate 30 curved complementary to the bush housing plate 20 and has an inner surface that abuts the gun tube 13 and an outer surface that abuts the rubber pad 18. End flanges 32 extend in the direction of the bush housing 14 from the respective opposite ends of the cradle bush plate 30. The cradle bush 16 is made of brass to provide a smooth surface on which the gun tube 13 is supported and on which it slides, thus minimising friction.
In use, when the gun is fired and a projectile passes through the gun tube 13, the latter slides in the annular support assembly 10. Expansion of the gun tube owing to internal gas pressure behind the projectile as it passes through the gun tube support assembly 10, is absorbed and dampened by the rubber pad 18.
It will be appreciated that the rubber pad 18 absorbs and dampens kinetic energy such as vibrations, and restricts it from being transferred from the passing projectile through to the cannon structure when the gun is fired. The cradle bush is biased in the direction of the gun tube to keep the cradle bush in contact with the gun tube and to allow for thermal expansion of the gun tube. Metal fatigue is therefore limited and internal and external ballistics not as greatly affected. The applicant further foresees that less transversal forces will act on the projectile, thus increasing its performance. It will further be appreciated that gun-jump and firing moment will be reduced through use of the gun tube support assembly 10.
It will also be appreciated that variations in detail are possible with a gun tube support assembly, a cradle for carrying a gun tube including a gun tube support assembly, and a gun provided with a gun tube support assembly according to the invention without departing from the scope of the appended claims.
Number | Date | Country | Kind |
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02/10079 | Dec 2002 | ZA | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/ZA03/00182 | 12/8/2003 | WO | 00 | 6/7/2005 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2004/053418 | 6/24/2004 | WO | A |
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3606218 | Enlund et al. | Sep 1971 | A |
4125052 | Thomas | Nov 1978 | A |
4168049 | Peritt | Sep 1979 | A |
4483235 | Hallqvist | Nov 1984 | A |
4638714 | Heintz et al. | Jan 1987 | A |
5703318 | Franchino et al. | Dec 1997 | A |
Number | Date | Country |
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559586 | Feb 1944 | GB |
1099651 | Jan 1968 | GB |
2 157 406 | Oct 1985 | GB |
Number | Date | Country | |
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20060112818 A1 | Jun 2006 | US |