WO1997025586A1

WO1997025586A1 - Case base/combustible cartridge case joint

Info

Publication number: WO1997025586A1
Application number: PCT/US1996/017754
Authority: WO
Inventors: John J. Dineen; Andrea L. Zivari-Giannoglou
Original assignee: Dineen John J; Zivari Giannoglou Andrea L
Priority date: 1996-01-04
Filing date: 1996-11-04
Publication date: 1997-07-17
Also published as: AU7669896A

Abstract

A new joint for use in combustible cartridge case munitions which reduces the risk of combustible cartridge case and case base and seal assembly separation during routine handling and minimizes the problems related to dechambering, comprised of a seal (16) mated to the case base (11) and into the exterior of the combustible cartridge case (10).

Description

CASE BASE/COMBUSTIBLE CARTRIDGE CASE JOINT

The invention described herein may be manufactured, used and licensed by or for the U.S. Government for Governmental purposes.

BACKGROUND OF THE INVENTION I. Field of Invention

This invention relates to the problems related to the handling of combustible case cartridges and the chambering and dechambering of such cartridges wherein the case base partially separates or completely separates from the combustible cartridge case, creating a hazard.

II. Background of the Invention

Surveillance reports of the 120mm tank ammunition have shown that the case base and seal assembly (Figure 3) partially separates or completely separates from the combustible cartridge casing 10 during routine handling. This separation is due to the deformation of the spring disc 12 which holds the combustible cartridge casing 10 in place at the cases's 10 dome area 13.

In addition, when the obturator 14 of the cartridge 10 is swollen, a cartridge 10 chambered with enough force could cause the cartridge 10 to deform away from the case base and seal assembly (Figure 3) and stick in the gun tube. This would make dechambering even more difficult.

Any dechambering difficulty is exaggerated because pulling on the case base 11 is required to extract the entire cartridge (Figure 1), which could cause the case base and seal assembly (Figure 3) to separate from the combustible cartridge case 10 and a propellant 22 spill could then occur.

This invention provides a new method of attaching a case base and seal assembly (Figure 3) to the combustible cartridge case.

SUMMARY OF INVENTION It is an object of this invention to provide a new joint between the case base and seal assembly and the combustible cartridge case which eliminates the problems of case base to combustible cartridge case separation.

It is still a further object of this invention to provide a case base and seal assembly to the combustible cartridge case joint which is reasonable to manufacture using a mold for the rubber seal in lieu of any machining of the case base.

It is a further object of this invention to enable the case base and seal assembly and combustible cartridge case to interface only at the joint area, allowing the removal of the dome area, thus decreasing the likelihood of burning residue from the combustible cartridge case.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic of typical 120mm tank ammunition. Figure IA is a rear view of the existing case base and seal assembly.

Figure IB is a detail of the current joint with the use of a retaining ring and spring disc whose location is identified in Figure 1. Figure 2 is a schematic which defines the dome area of the existing combustible cartridge case.

Figure 2A is a rear view of the dome area of the combustible cartridge case.

Figure 3 is a cross sectional view of the case base identifying the detail area of the seal to be found at Figure 3A.

Figure 3A is a detail area A of the seal found attached to the case base.

Figure 3B is a view of the rear of the case base. Figure 4 is a cross-sectional view of a case base and seal assembly mated to the exterior of the combustible cartridge case. The seal is one monolithic piece which acts as a male portion of the joint. It is fitted into the female portion of the combustible cartridge case. The combustible cartridge case is snapped into the case base and seal assembly.

Figure 5 depicts the changed combustible cartridge case which is used as the male portion of the joint. Figure 6A is the detail of the silicone rubber seal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 is the schematic of a typical 120mm tank round of ammunition. Figures 2 and 3 depict the various elements of the prior art which are involved in the separation and dechambering problem. In particular, the current joint between the case base and seal assembly (Figure 3) with the combustible cartridge case 10 are shown in Figure 1. Figure 3A shows the tear drop male connector 19 mated to the current seal 16. Figure 4 shows the new case base and seal assembly (Figure 3) mated to the combustible cartridge case 10 joint developed. The detent 18 is part of the rubber seal of the case base and seal assembly 16 and is used to secure the side wall 15 of the combustible cartridge case 10.

Figure 4 further depicts a design wherein it is found to be rigid enough because the rubber detent 18 is between the metal "tear drop" 19 of the case base 11 and combustible cartridge case 10. Only a new mold is required to mold the rubber seal 16, rather than any machining of the case base 11. Figure 5 depicts that the mating combustible cartridge case 10 only requires machining of the groove 18 as part of its regular production. Assembly of the joint as shown in Figure 6 requires only the pressing of the combustible cartridge case 10 into the case base 11 as shown in Figure 4.

Figure 5 depicts the grooved area 18 machined into the combustible cartridge case 10 at the time of manufacture of the said combustible cartridge case 10 which allows the rubber seal with its detent 16 to fit onto the very surface of the combustible cartridge case 10.

Figure 6 and Figure 6A show the design which enables the case base and seal assembly (Figure 3) and combustible cartridge case 10 to interface only at the joint area 21 described at Figure 6A. This makes removing the dome area 13 shown at Figure 2 of the combustible cartridge case 16 feasible, thus decreasing the likelihood of burning residue from the combustible cartridge case 10 when fired.

Burning residue is a great risk of 120mm tank ammunition because if burning residue exists in the gun while another cartridge 10 is chambered, the cartridge

10 could ignite. Furthermore, the retaining ring 20 and spring clip as shown at Figure 1 and Figure IB would no longer be needed, thus eliminating the cost of those components and their associated assembly procedures.

The new joint 21 at Figures 6, 6A has proven to be 40% stronger than the old design shown in Figure 3A in pull tests. Furthermore, the new joint 21 has also passed an array of drop tests. Lastly, the new joint 21 shows that there is no pulling away of the case base

11 from the combustible cartridge case 10, as there is in the current design at Figures 1, 2, 3.

In the preferred embodiment, the changed combustible cartridge case 10 at Figure 5 is pressed into the base case and seal assembly at Figure 6 to yield the new case base to combustible cartridge case joint 21 as shown in Figures 4 and 6.

Thus, it is apparent that in accordance with the present invention, a functional design that fully resolves a serious military munitions problem is set forth above. While the invention has been described in conjunction with a specific embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the light of the foregoing descriptions. Accordingly, it is intended that the present invention embrace all such alternatives, modifications, and variations as fall within the written spirit and broad scope of the appended claims.

Claims

What is claimed is:

1. A new joint between the case base and seal assembly and combustible cartridge case, which prevents separation during routine handling, eases dechambering and increases safety, comprising: means to mate the inside of the case base and seal assembly to the exterior of the combustible cartridge case; and means to secure the side wall of the combustible cartridge case to the case base and seal assembly.

2. A new joint as in claim 1 wherein the means to mate the inside of the case base and seal assembly to the exterior of the combustible cartridge case comprises a monolithic detent which mates into the tear drop found in the case base and seal assembly.

3. A new joint as in claim 1 wherein the means to secure the side wall of the combustible cartridge case to the case base and seal assembly comprises the use of a detent on the silicone rubber seal ring which mates to the machined groove on the surface of the combustible cartridge case.

4. A new joint as in claim 1 wherein the dome area normally found in current combustible cartridge cases can be removed.

5. A new joint which interfaces only at the case base and combustible cartridge case, without the need for a dome area, which prevents separation during routine handling, eases dechambering and increases safety, comprising: means to mate the inside of the case base and the exterior of the combustible cartridge case; and means to secure the side wall of the combustible cartridge case to the case base.

6. A new joint as in claim 5 wherein the means to mate the inside of the case base and seal assembly to the exterior of the combustible cartridge case comprises a detent which is part of the seal which mates into the tear drop found in the case base and seal assembly.

7. A new joint as in Claim 5 wherein the means to secure the side wall of the combustible cartridge case to the case base and seal assembly comprises the use of a detent on the rubber seal ring which mates to the machined groove or the surface of the combustible cartridge case.