Ammunition and explosives – Projectiles – Composite
Reexamination Certificate
1998-09-22
2001-05-22
Price, Thomas (Department: 3641)
Ammunition and explosives
Projectiles
Composite
Reexamination Certificate
active
06234082
ABSTRACT:
BACKGROUND OF THE INVENTION
The technical scope of the invention is that of projectiles, in particular large-calibre long-range field artillery projectiles.
An increase in the range of artillery projectiles has long been sought after. Thus, a base-bleed has been installed to the tail end of ballistic trajectory projectiles which is designed to reduce the drag of the base by means of the emission of gases developed by the combustion of a composition such as propellant. The base-bleed only increases the range of the projectiles by around 5 to 10% and generates dispersions, which prejudice firing accuracy.
A further proposition to increase firing accuracy has been made consisting in effecting a correction of the trajectory or by terminal guidance. But as ballistic trajectory projectiles are spin-stabilised, it is very difficult to carry out accurate trajectory correction or terminal guidance. Moreover, only accuracy is improved, the range remaining relatively short.
Patent WO100908 proposes an artillery projectile fitted with a base-bleed having a drive band, piloting ailerons and stabilising fins. This projectile is fin-stabilised over part of its trajectory during which the base-bleed is operational, and then the base-bleed is ejected, which enables the deployment of the stabilising fins, which brake the rotation of the projectile. The projectile is thus on a trajectory stabilised by its fin tailpiece. Thereafter, terminal guidance can be carried out by means of the piloting ailerons.
Such a concept has several drawbacks. Firstly, the passage from a spin-stabilised trajectory to a fin-stabilised trajectory generates numerous constraints. In fact, the fin tailpiece is subjected to strong mechanical stresses during its deployment, which can generate a loss in the stability of the projectile and/or considerable dispersion. Furthermore, as explained previously, the range of such a projectile is relatively short.
SUMMARY OF THE INVENTION
The aim of the invention is to propose a projectile, which is simple, inexpensive, and has a considerable firing range.
Thus, the subject of the invention is an artillery projectile, designed to be fired from a large-calibre gun barrel, which comprises a body whose rear part is fitted with deployable stabilising fins, wherein the body is sub-calibred and carries at least one ejectable guiding sabot fitted with a sliding drive band intended to reduce the spin rate of the projectile.
According to a particular embodiment the guiding sabot is positioned at a rear part of the projectile body whilst holding the deployable stabilising fins in place, their deployment being carried out when the rear sabot is ejected upon exiting the barrel.
It advantageously comprises a second guiding sabot positioned at a front part of the projectile and ejectable upon exiting the barrel.
The front sabot is formed of at least two segments connected to the body by a temporary connecting means formed of at least one shearable pin, whose shearing is caused by the relative recoil of the sabot with respect to the body of the projectile during the longitudinal acceleration of the projectile in the gun barrel.
The front sabot advantageously possesses an inner profile which matches an external profile of the front part of the projectile and there is an axial clearance between the inner profile of the sabot and the external profile of the front of the projectile so as to allow the relative recoil of the sabot with respect to the projectile body during its longitudinal acceleration in the gun barrel.
According to one embodiment, the projectile incorporates in its front part deployable piloting ailerons.
The rear sabot advantageously comprises a thrusting part which receives the sliding drive band and a tubular part covering the rear part of the projectile body whilst keeping the stabilising fins in their folded-back position.
According to a particular embodiment, the projectile comprises a rear booster.
According to a first variant embodiment, the rear sabot is ejected upon exiting the gun barrel by means of the pressure generated by the booster.
According to a second variant embodiment, the rear sabot is ejected by means of a pyrotechnic charge placed between the thrusting part of the rear sabot and the rear part of the projectile body.
The tubular part of the rear sabot is preferentially provided with longitudinal zones of embrittlement, which are intended to break during the ejection of the sabot so as to increase its aerodynamic drag.
REFERENCES:
patent: H905 (1991-04-01), Rottenberg
patent: 2941470 (1960-06-01), Jasse
patent: 3620167 (1971-11-01), Romer et al.
patent: 3834314 (1974-09-01), Young
patent: 3845922 (1974-11-01), Mayer
patent: 3905299 (1975-09-01), Feldmann
patent: 3961580 (1976-06-01), Burnett et al.
patent: 4209146 (1980-06-01), Mattson
patent: 4332360 (1982-06-01), Topliffe
patent: 4430943 (1984-02-01), Bock et al.
patent: 4534294 (1985-08-01), Von Laar et al.
patent: 4653404 (1987-03-01), Halverson
patent: 4756255 (1988-07-01), Rosenberg et al.
patent: 4776280 (1988-10-01), Burri et al.
patent: 4833995 (1989-05-01), Gotz et al.
patent: 4944226 (1990-07-01), Wedertz et al.
patent: 5020436 (1991-06-01), Coburn
patent: 5164540 (1992-11-01), Chiarelli et al.
patent: 5182419 (1993-01-01), Burnette
patent: 5196650 (1993-03-01), Cytron
patent: 3243430 (1984-05-01), None
patent: 3730359 (1992-01-01), None
patent: 2008535 (1970-01-01), None
patent: 2098933 (1972-02-01), None
patent: 1516073 (1978-06-01), None
patent: 81/00908 (1981-04-01), None
Cros Anne-Laure
Lamorlette Gérard
Giat Industries
Parkhurst & Wendel LLP
Price Thomas
LandOfFree
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