Ammunition sabot and projectile

• US 4,735,147 A
• Filed: 02/27/1985
• Issued: 04/05/1988
• Est. Priority Date: 03/01/1984
• Status: Expired due to Term

• Current Assignee: OLIN Corporation
• Original Assignee: OLIN Corporation
• Inventors: Halverson, Henry J.
• Primary Examiner(s): Tudor, Harold J.
• Application Number:
  US06/705,957
• Time in Patent Office: 1,133 Days
• Field of Search: 102/458, 102/513, 102/520-523, 102/532
• US Class Current: 102/520
• CPC Class Codes: F42B 14/064 Sabots enclosing the rear end of a kinetic energy projectile, i.e. having a closed disk shaped obturator base and petals extending forward from said base
• CPC Class Codes: F42B 14/067 Sealing aspects in sabots, e.g. sealing between individual segments of the sabots or sealing between the outer surface of the sabot and the inner surface of the barrel
• CPC Class Codes: F42B 14/068 Sabots characterised by the material F42B14/067 takes precedence

Abstract

A high velocity traced armor penetrating subcaliber projectile core having sealed radial spin-up notches on its base is disclosed. Also disclosed, is a plastic sabot for launching a traced subcaliber high velocity armor penetrating projectile core, which sabot is a cup shaped plastic body with a sealed passageway through its base and longitudinal weakening slots on the inside of its walls, the slot extending only part way down the inner surface of the wall to leave a cylindrical sealing surface adjacent the sabot base, whereby to provide a waterproof seal surrounding the rearend of the core and the tracer charge.

Claims

1. A traced sabot projectile which comprises:

a hard metallic penetrator core having;

a forwardly tapered forward end;

a cylindrical rear portion defining a central rearwardly open tracer cavity;

a tracer charge within the tracer cavity;

a flat annular rear surface orthogonal to the axis of the core;

at least one spin-up on said rear surface;

a cylindrical generally forwardly opening cup-shaped rigid plastic sabot coaxial with and surrounding the rear surface and rear portion of the core and having;

an annular sealing surface disposed radially between the spin-up notch and the tracer cavity so as to prevent gas escape from said tracer cavity through said notches;

a cylindrical wall defining a forwardly opening cavity adapted to receive the core;

a metallic support plate having a central passageway passing axially therethrough, the plate being located at and forming a closed base of the cavity and the plate being symmetrical about its axis, its axis being aligned coaxially to the axis of the core;

a base portion attached to the rear of the cylindrical wall and having at least one passageway axially therethrough from the rear to the front of the base portion, the passageway of the sabot having a diaphragm thick enough to seal the tracer charge from the environment prior to launch but thin enough to be destroyed by propellant gas pressure during launch so as to allow the propellant gases to pass through the passageway in the sabot base to ignite the tracer charge; and

said plastic sabot being made of a plastic material with an Izod impact strength of less than 12 ft. lbs./in. of notch when tested under ASTM Test Method D256, a compressive strength of at least 15,000 psi when tested under ASTM Test Method D695, a shear strength of at least 12,000 psi when tested under ASTM Test Method D732 and a tensile strength of at least 12,000 psi when tested under ASTM Test Method D1708.

2. The sabot projectile of claim 1 wherein there are at least two notches on said rear surface and located symmetrical with respect to the longitudinal axis of the projectile core.

6. The sabot projectile of claim 2 therein the cylindrical wall of the sabot has a plurality of longitudinally extending petals extending axially along an inner surface of the sabot whereby to leave a circumferentially continuous outer bourrelet surface on the sabot to increase obturation and decreasing balloting, each petal being separated by a weakened section extending longitudinally only along a major front portion of the axial length of the inner surface between each pair of adjacent petals.

7. The sabot projectile of claim 6 wherein the cylindrical wall has a continuous cylindrical inner surface adjacent the base of the forward opening sabot cavity for sealing against rear portion of the penetrator to help seal the tracer charge from the environment prior to launch.

8. The sabot of claim 6 wherein each of said sabot petals has a circumferentially weakened section to predetermine the location of petal separation from the sabot during sabot disintegration following launch.

9. The sabot of claim 8 wherein the weakened section are notches on the internal surface of the cylindrical wall of the sabot.

10. The sabot projectile of claim 9 wherein the sabot wall has a forwardly tapered front portion.

3. A traced sabot projectile which comprises:

(a) a hard metallic penetrator core having;

a forwardly tapered forward end;

a cylindrical tubular rear portion defining a central rearwardly open tracer cavity;

a tracer charge within the tracer cavity;

a flat annular rear surface orthogonal to the axis of the core;

at least one spin-up notch on said rear surface; and

the notch being axially deeper at its outward radial end than at its inner radial end, so as to allow the inner end of the notch to be sealed against the support plate during launch, whereby to prevent gas flow into the sabot cavity through the notch;

(b) a plastic sabot having;

a cylindrical wall defining a forwardly opening a cavity adapted to receive the core;

a base portion attached to the rear of the cylindrical wall and having at least one passageway axially therethrough; and

said sabot being made of a plastic material with an Izod impact strength of less than 12 ft. lbs./in. of notch when tested under ASTM Test Method D256, a compressive strength of at least 15,000 psi when tested under ASTM Test Method D695, a shear strength of at least 12,000 psi when tested under ASTM Test Method D732 and a tensile strength of at least 12,000 psi when tested under ASTM Test Method D1708.

(c) a metallic support plate having a central passageway passing axially therethrough, the plate being located at and forming a closed base of the cavity and the plate being symmetrical about its axis, its axis being aligned coaxially to the axis of the core.

4. The sabot projectile of claim 3 wherein there are at least two spin-up notches on the rear surface of the core and located symmetrically about the axis of the core.

5. The sabot projectile of claim 4 wherein the tracer cavity is cylindrical and of a larger diameter than the diameter of the passageway in the sabot, so as to allow the sabot to support the tracer charge during launch.

11. A small caliber ammunition sabot for launching a hard metallic core which sabot comprises:

a cylindrical wall defining a forwardly opening a cavity adapted to receive the core;

a metallic support plate having a central passageway passing axially therethrough, the plate being located at and forming a closed base of the cavity and the plate being symmetrical about its axis, its axis being aligned coaxially to the axis of the core;

a base portion attached to the rear of the cylindrical wall and having at least one passageway axially therethrough communicating with the passageway through the support plate;

a rupturable diaphragm in the passageway for sealing the passageway prior to launch but rupturing in response to gun gas pressure during launch so as to allow for ignition of any ignitable mixture which is in the rear of the core; and

the wall, base portion and diaphragm being integrally molded of a plastic material with an Izod impact strength of less than 12 ft. lbs./in. of notch when tested under ASTM Test Method D256, a compressive strength of at least 15,000 psi when tested under ASTM Test Method D695, a shear strength of at least 12,000 psi when tested under ASTM Test Method D732 and a tensile strenth of at least 12,000 psi when tested under ASTM Test Method D1708.

12. The sabot projectile of claim 11 wherein the cylindrical wall of the sabot has a plurality of longitudinally extending petals each separated by a weakened section extending longitudinally between each pair of adjacent petals, the weakened sections extending axially only partially along an inner wall of the sabot and the section each having a rearwardly pointed rear end.

13. The sabot projectile of claim 11 wherein the cylindrical wall has a continuous cylindrical inner surface adjacent the base of the forward opening sabot cavity for sealing against rear portion of the penetrator to help seal the tracer charge from the environment prior to launch.

14. The sabot of claim 11 wherein said wall has a circumferentially weakened section adjacent the base portion to predetermine the location of petal separation from the sabot during sabot disintegration following launch.

15. The sabot of claim 13 wherein the weakened section are notches on the internal surface of the cylindrical wall of the sabot.

16. The sabot projectile of claim 14 wherein each of the petals has a forwardly tapered front portion.

17. A traced sabot projectile having a longitudinal axis which projectile comprises:

a subcaliber projectile core having a cylindrical rear portion with a tracer cavity open therein communicating with a rear end of the core;

a solid rigid plastic sabot having a cylindrical forward wall portion sealingly surrounding the rear portion and having a cylindrical rear base portion with at least one passageway communicating the rear of the sabot with the tracer cavity and having a waterproof rupturable seal in the passageway adapted to be ruptured by gun propellant gas pressure during lauanch of the projectile whereby said tracer cavity is waterproof sealed from the environment exterior of the projectile until launch but upon launch the seal is ruptured to allow ignition of the tracer charge during launch, thus, eliminating the need for a separate seal in the tracer cavity itself; and

said sabot being made of a plastic material with an Izod impact strength of less than 12 ft lbs./in. of notch when tested under ASTM Test Method D256, a compressive strength of at least 15,000 psi when tested under ASTM Test Method D695, a shear strength of at least 12,000 psi when tested under ASTM Test Method D732 and a tensile strength of at least 12,000 psi when tested under ASTM Test Method D1708.

18. The sabot projectile of claim 17 wherein said seal is a plastic barrier molded integrally with the remainder of the plastic sabot.