Artillery projectile with spreading tail assembly

• US 3,944,168 A
• Filed: 03/07/1974
• Issued: 03/16/1976
• Est. Priority Date: 03/14/1973
• Status: Expired due to Term

• Current Assignee: Etat Francais
• Original Assignee: Etat Francais
• Inventors: George, Michel, Bizien, Jean-Pierre, Patouilliart, Rene G.
• Primary Examiner(s): Pendegrass, Verlin R.
• Application Number:
  US05/449,090
• Time in Patent Office: 740 Days
• Field of Search: 244/3.27, 244/3.28, 244/3.29
• US Class Current: 244/3.28
• CPC Class Codes: F42B 10/20 deployed by combustion gas pressure, or by pneumatic or hydraulic forces

Abstract

The invention relates to an artillery projectile with spreading tail assembly and a synchronization ring for controlling the orientation of the fins of the tail assembly. The synchronization ring slides on an extension of the projectile base and includes a first means cooperating with at least one piston seated in the projectile base to hold the synchronization ring in the forward position on the one hand, and on the other hand a second means cooperating with a projection of the respective fins to hold the fins in folded position inside the launcher tube when the synchronization ring is held in the forward position. The fins are spread when the ring moves to its rearward position. The movement of the ring may be under the control of one or more of the launching pressure at the projectile base, inertia, a specially generated pressure, rotational forces, or combinations of these.

Claims

1. In an artillery projectile for launching by means of a launch tube, the combination comprising a spreading tail assembly on the base of the projectile, said tail assembly comprising fins that respectively pivot in a plane that passes through the longitudinal axis of the projectile, about an axis perpendicular to said plane, said fins having an internal edge with at least one projection, means forming an extension of the projectile base, a synchronization ring slidable concentrically on said extension of the projectile base from a forward position to a rear position to cause the simultaneous spreading of the fins and ensure their clamping in the spread position, means forming at least one axially oriented cylinder in the projectile base, a piston slidably mounted in each such cylinder for movement between forward and rear positions and constructed and arranged such that the rear face of said piston will be subjected to the pressure prevailing at the rear of the projectile base and hence the pressure in a launch tube during departure of the projectile, said synchronization ring having, on the one hand, first means cooperating with said at least one piston slidably seated in said cylinder in the projectile base, such that the rear face of said piston will be subjected to the pressure prevailing in a launch tube during departure of the round, to hold the synchronization ring in the forward position with said piston because of launch tube pressures during firing, and, on the other hand, second means cooperating with the said projections of the respective fins to hold the fins in folded position inside the launcher tube when the synchronization ring is held in the forward position, and gas pressure means for subjecting the forward face of said piston to gas pressure during launching, said gas pressure means comprising an enclosed space in said projectile base, means for pressurizing said space during launching, and means for preventing egress of gas from said space at least until destruction of said projectile, such that said gas pressure acts against said forward face of said piston throughout substantially the entire flight of said projectile.

2. Projectile as in claim 1, wherein said first means is an annular groove in which a cap of said piston engages.

3. Projectile as in claim 1 wherein said second means is an annular groove in which said projections of the respective fins engage.

4. Projectile as in claim 1 wherein said first and second means comprise a single annular groove in which there are simultaneously engaged a cap of said piston and said projections of the respective fins.

5. Projectile as in claim 1 wherein said gas pressure means includes gas generator means, and wherein the piston is a differential piston on the forward small face of which the gases produced by the gas generator means act.

6. Projectile as in claim 5 characterized in that said generator means comprises means for bleeding gas from a launch tube, in which the projectile is located during firing, into a space in the projectile and subsequently to the small face of said differential piston.

7. Projectile as in claim 6 wherein said means for bleeding gas comprises a one-way valve in said base for effecting one-way flow of gas from the area adjacent the rear face of the base to a space in the projectile, and means for feeding gas from said space to the small face of said differential piston in dependence on the relative pressures in said space and the area adjacent the rear face of the base of the projectile.

8. Projectile as claimed in claim 1 wherein said piston and its cylinder are oriented with their axis parallel to but radially offset from the axis of the projectile, said synchronization ring is slidably mounted on said axial extension of the base of the projectile, and said first means operatively couples said piston to said ring so as to prevent rearward movement of said ring apart from said piston.

9. Projectile as claimed in claim 8 wherein said second means comprises means on said ring for holding the projection of each fin in captive relationship when said fins are in the folded position and said ring is in its forward position, whereby to prevent spreading of said fins until said ring moves rearwardly from its forward position.

10. Projectile as claimed in claim 7 wherein said means for feeding gas from said space to the small face of said differential piston comprises a pressure responsive slide valve having one face exposed to pressure in said space and an opposite face exposed to pressure adjacent the rear face of said projectile, a passage for communicating said space and the small face of said differential piston, and means biasing said slide valve to a normal position in which it closes said passage, said slide valve being oriented such that pressure in said space acts on said one face to urge said slide valve to a position in which it opens said passage, and such that pressure acting on said opposite face urges said slide valve to a position in which it closes said passage.

11. Projectile as claimed in claim 10 wherein said oneway valve is located in and controls a passage in said slide valve connecting said one face and said opposite face.

12. Projectile as claimed in claim 11 wherein said slide valve is a differential piston, said one face constituting the small face and said opposite face constituting the large face thereof.

13. Projectile as claimed in claim 5 wherein said differential piston has a forward small face, a rear large face, and an intermediate face oriented oppositely from said rear large face, said cylinder having a portion housing said intermediate face at least while said piston is in its forward position so that said intermediate face is sealed from the gas pressures prevailing on said forward and rear faces, said cylinder being constructed and arranged such that said intermediate face is opened to the pressure prevailing on said rear large face at a predetermined point in the movement of said piston from its forward to its rearward position, whereby to increase the effective gas pressure thrust on said piston in the rearward direction.

14. Projectile as claimed in claim 1 wherein said synchronization ring encompasses and is slidably mounted on at least a portion of said extension, and said piston comprises a differential piston having a relatively small forward face and a relatively large rear face, said piston being disposed radially outwardly from said synchronization ring.