Improved line charge

Abstract

A line charge system includes a series of spaced explosive sections each including a rigid tube, an explosive slab with an edge abutting one side of the rigid tube, and an explosive strap extending from one face of the explosive slab, over the rigid tube, and along an opposite face of the explosive slab. A detonation cord extends through the rigid tubes of the explosive sections. The detonation cord, when initiated, directly detonates the explosive slab and the explosive strap which also detonates the explosive slab.

Description

[0001] IMPROVED LINE CHARGE

[0002] RELATED APPLICATIONS

[0003] This application claims benefit of and priority to U.S. Patent Application Serial No. 19 / 227,734 filed June 4, 2025 under 35 U.S.C. §§119, 120, 363, 365, and 37 C.F.R. §1.55 and §1.78, and that application and this application claim benefit of and priority to U.S. Provisional Application Serial No. 63 / 671,316 filed July 15, 2024, under 35 U.S.C. §§119, 120, 363, 365, and 37 C.F.R. §1.55 and §1.78, which are both incorporated herein by this reference.

[0004] FIELD OF THE INVENTION

[0005] The invention relates to line charges and use for demolition, breaching, obstacle clearing, unexploded ordnance (UXO) reduction, and other tasks.

[0006] BACKGROUND OF THE INVENTION

[0007] Line charges can be used for demolition, breeching, obstacle dealing, clearing unexploded ordinance, mines, to expose and destroy improvised explosive devices, to breech counter-maneuver ability features and obstacles such as fences, walls, timber, steel, concrete, wire obstacles, or the like. Some line charges are heavy, complex and difficult to manufacture and deploy.

[0008] Line charges typically include spaced explosive charges connected via a detonation cord. U.S. Patent No. 6,439,099, incorporated herein by this reference, discloses spaced cylindrical charges and a detonation cord within a yam structure. U.S. Patent No. 8,904,937, incorporated herein by this reference by the Assignee hereof, results in a fairly lightweight and fairly effective line charge system.

[0009] SUMMARY OF THE INVENTION

[0010] Featured are improvements to and new functionality associated with that prior line charge system.

[0011] Featured is a line charge system comprising a series of spaced explosive sections each including a rigid tube, an explosive slab with an edge abutting one side of the rigid tube, and an explosive strap extending from one face of the explosive slab, over the rigid tube, and along an opposite face of the explosive slab. A detonation cord extends through the rigid tubes of the explosive sections. The detonation cord, when initiated, directly detonates the explosive slab and the explosive strap which also detonates the explosive slab.

[0012] In one example, the line charge system further includes a clamshell housing for each explosive section about the explosive strap and the explosive slab and a flexible sock housing the spaced explosive sections and the detonation cord.

[0013] Preferably, the rigid tube has an outer diameter equal to or less than the thickness of the explosive slab. The rigid tube can be made of paper or plastic and typically is made of a nonexplosive material.

[0014] Also featured is a method of manufacturing a line charge. An explosive strap is valid in an open clamshell housing and a rigid tube is centered across the explosive strap. The clamshell housing is partially closed to hold the explosive strap and rigid tube therein. An explosive slab is disposed edgewise onto the rigid tube and the clamshell housing is fully closed to engage the explosive strap about opposite faces of the explosive slab and to envelop the explosive slab, explosive strap, and rigid tube therein. A detonation cord is disposed inside the rigid tube.

[0015] In one example, the detonation cord is disposed inside the rigid tube before the rigid tube is placed on the explosive strap.

[0016] The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives.

[0017] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0018] Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:

[0019] Fig. 1 shows a prior line charge system;

[0020] Fig. 2 shows a portion of a line charge system in accordance with an example of this disclosure;

[0021] Fig. 3 is a schematic view of an explosive section;

[0022] Fig. 4 is a cross-sectional view of the explosive section of Fig. 3; and

[0023] Figs. 5A-5F depict one method of assembling an improved line charge system.

[0024] DETAILED DESCRIPTION OF THE INVENTION Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.

[0025] The line charge system of Patent No. 8,904,937 is shown in Fig. 1. Each explosive section 12a, 12b includes a plastic tray 20 retaining explosive slab 14a and spaced explosive booster cylinders 16a and 16b located in tray 20 cradles 22. Explosive tapes 18a, 18b are pressed onto and around explosive slab 14a. Detonation cord 24 is threaded through the explosive booster cylinders 16a and 16b.

[0026] In testing and deployment, it was found the booster cylinders radiate most of the energy, when detonated, radially in all directions and very little energy is imparted into the explosive slab. Nearly 80% of the energy is lost to the atmosphere. Initiation of the explosive slab was not guaranteed.

[0027] Also, the soft booster cylinders sometimes were crushed during handling, storage, and / or deployment and then the explosive sections could no longer rotate about the detonation cord. So, some explosive sections did not lie flat relative to and were less effective at coupling energy into the intended target (e.g., the ground).

[0028] The large diameter booster cylinders and the tray cradles for the booster cylinders also raise the top end of the explosive sections off the target decreasing the ability to directly couple explosive energy into the target.

[0029] The large diameter booster cylinders also resulted in a bulkier, thicker line charge when it was rolled or stacked and the booster cylinders of adjacent explosive sections abutted each other.

[0030] The large diameter booster cylinders also added weight to the line charge system.

[0031] In addition, the prior line charge system had to be manufactured by hand. And, feeding the detonation cord through the numerous booster cylinders, some of which may have been deformed or crushed, was tedious and time consuming. Manual assembly in general is expensive and time consuming.

[0032] Featured is an improved line charge system. Also featured is an improved line charge system in which detonation energy is better coupled into the explosive slabs and in which the explosive slabs better conform to the target surface. In some examples, the improved line charge system is thinner and lighter weight and can be manufactured / assembled using automated processes. In some examples, the improved line charge system features fewer overall parts which enables a lower cost system. The optional housing can also be made at a lower cost. The individual line charge sections exhibit greater rotational flexibility. Initiation reliability is improved as is the overall strength of each explosive section. By eliminating air gaps, there is better target to charge coupling. A thinner profile is possible and also enhances smoother deployment. The improved line charge system may have a lighter overall system weight due to the lower volume. Assembly automation can be simplified. Figs. 2-3 depict an example of an improved line charge system with spaced explosive sections 30a and 30b each including a rigid tube 32 (e.g., plastic or paper) preferably not made from explosive material and thus more rigid than the prior explosive booster cylinders made of explosives such as RDX, PETN, or other materials. Explosive slab 34 has an edge 36 abutting one side of the rigid tube 32. Explosive strap 38 extends from one face (e.g., the top) of explosive slab 34, over rigid tube 32, and along an opposite (e.g., bottom) face of the explosive slab. Detonation cord 40 extends through the rigid tubes of all explosive sections. Both explosive slab 34 and explosive strap 38 can be made of or include RDX or PETN or other explosive material sufficient to propagate and initiate the explosive slab.

[0033] The result is that the detonation cord 40 directly detonates the explosive slab 34 (by virtue of the close adjacent relationship between an edge of the explosive slab and the detonation cord inside tube 32) and the detonation cord also directly detonates the explosive strap 38 (by virtue of the explosive strap extending over tube 32 carrying the detonation cord 40) and the explosive strap also directly detonates the explosive slab 32. Preferably, each rigid tube has an outer diameter less than or equal to the thickness of the explosive slab.

[0034] Figure 4 shows the addition of housing 50 about the explosive strap 38 and slab 34. Housing 50 can be a plastic shell or wrap.

[0035] In one example, clamshell housing 52, Fig. 5A, is in its open configuration and explosive strap 38, Fig. 5B is laid in open clamshell housing 52. Rigid tube 32 is then centered across explosive strap 38, Fig. 5C. The clamshell housing is then partially closed as shown in Fig. 5D to hold the explosive strap and rigid tube 32 therein and then explosive slab 34 is disposed edgewise onto rigid tube 32, Fig. 5E. Then, clamshell housing 52 is fully closed, Fig. 5F, to engage the explosive strap about the opposite faces of the explosive slab and to envelope the explosive slab 34, explosive strap 38, and rigid tube 32 therein. Tape 54 or an integrated locking tab or other locking feature can be used to retain the clamshell housing in its closed configuration.

[0036] The detonation cord can be placed inside the rigid tube when it is laid in the clamshell housing or later as desired. The spaced, housed (or unhoused) line charge explosive sections can be placed in a flexible sock per U.S. Patent No. 8,904,937 as desired and folded or rolled as shown therein prior to deployment.

[0037] Preferably, no longer are the explosive booster cylinders used resulting in a more symmetric profile for each explosive section. The prior asymmetry caused by the explosive booster cylinders added considerably to the package volume. They also added drag that can impede an autonomous deployment. The outside diameter of the explosive booster cylinders also lifted the main explosive slab off the target diminishing the explosive effect. In addition, the cylinders often deformed which prevented the detonation cord from rotating freely. The cylinders also complicated the plastic tray design making it expensive and / or labor intensive.

[0038] In the improved line charge system, the energetic transfer is more reliable and the volume and sleekness of the new design improves pay load delivery remotely and / or autonomously.

[0039] Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. Other embodiments will occur to those skilled in the art and are within the following claims.

[0040] In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed; those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and / or there are many other reasons the applicant cannot be expected to describe certain insubstantial substitutes for any claim element amended.

[0041] Other embodiments will occur to those skilled in the art and are within the following claims.

[0042] What is claimed is:

Claims

CLAIMS1. A line charge system comprising: a series of spaced explosive sections each including: a rigid tube, an explosive slab with an edge abutting one side of the rigid tube, and an explosive strap extending from one face of the explosive slab, over the rigid tube, and along an opposite face of the explosive slab; and a detonation cord extending through the rigid tubes of the explosive sections, the detonation cord, when initiated, directly detonating the explosive slab and the explosive strap which also detonates the explosive slab.

2. The line charge system of claim 1 further including a clamshell housing for each explosive section about the explosive strap and the explosive slab.

3. The line charge system of claim 2 further including a flexible sock housing the spaced explosive sections and the detonation cord.

4. The line charge system of claim 1 in which the rigid tube has an outer diameter equal to or less than the thickness of the explosive slab.

5. The line charge system of claim 1 in which the rigid tube is made of paperor plastic.

6. The line charge system of claim 1 in which the rigid tube is made of a nonexplosive material.

7. A method of manufacturing a line charge, the method comprising: laying an explosive strap in an open clamshell housing; centering a rigid tube across the explosive strap; partially closing the clamshell housing to hold the explosive strap and rigid tube therein; disposing an explosive slab edgewise onto the rigid tube; fully closing the clamshell housing to engage the explosive strap about opposite faces of the explosive slab and to envelop the explosive slab, explosive strap, and rigid tube therein; and disposing a detonation cord inside the rigid tube.

8. The method of claim 7 in which the detonation cord is disposed inside the rigid tube before the rigid tube is placed on the explosive strap.

9. The method of claim 7 further including disposing a series of clamshell housings and detonation cord sections inside a flexible sock.

10. The method of claim 7 in which the rigid tube has an outer diameter equal to or less than the thickness of the explosive slab.

11. The method of claim 7 in which the rigid tube is made of paper or plastic.

12. The method of claim 7 in which the rigid tube is made of a nonexplosive material.

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