Patent Description:
In the development of extended range artillery munitions, balancing the available space for various guidance and control elements and a conventional cylindrical fragmenting warhead in the guidance section, with the necessary space for an optimal propulsion system in the propulsion section, leads to significant space shortages within the artillery round. The limitations on space shared by the propulsion system, the guidance and control elements, and the warhead make it difficult to use standard space allocations in the artillery round. Prior solutions have included shortening the propulsion section and propulsion system to allocate more space for the cylindrical fragmenting warhead, or otherwise reducing the length of the cylindrical fragmenting warhead in the guidance section to create more space for the guidance and control hardware and electronics. Both of these prior solutions, however, lead to inadequate performance of the propulsion system while limiting warhead size and effectiveness.

CH <NUM><NUM> A discloses a self-propelled projectile in which the self-propelling charge is housed in a thin casing which is itself engaged in an axial longitudinal cavity formed in the payload which is, therefore, located in the annular space provided between the outer body and said casing, a nozzle being provided at the rear of said body for the ejection of the propulsion gases.

<CIT> discloses a guidance and control unit assembly for use with a munitions projectile including a guidance and control unit being roll isolated with respect to the munitions projectile such that roll of the munitions projectile about a projectile longitudinal axis, such roll being imparted to the munitions projectile during the act of launching the munitions projectile, may not be imparted to the guidance and control unit as desired.

<CIT> discloses an integral rocket and ramjet engine comprising in flow series, an intake duct for aerodynamically compressing air, one or more ports through which the compressed air passes from the intake duct, a combustion chamber, and a propelling nozzle; the engine being provided with one or more port covers which in a first position prevent air from en tering the combustion chamber and enable a rocket charge to be burnt in the combustion chamber thereby accelerating the engine to sufficient velocity for ramjet operation, the said one or more covers being movable axially to a second position within the combustion cham ber when the rocket charge is spent to allow compressed air to flow into the combustion chamber and the engine to operate as a ram jet; the said one or more port covers being constructed and arranged to provide a quiet zone within the combustion chamber, said quiet zone being substantially shielded from the main flow of compressed air into the combustion chamber when said one or more covers are in the second position.

<CIT> discloses an insensitive combined cycle missile propulsion system including a solid fuel contained within a first section of the missile, and a liquid oxidizer contained within a second section of the missile. A first conduit has a first valve communicating the fuel and the oxidizer and a second conduit, spatially removed from the first conduit, has a second valve communicating the fuel and the oxidizer. An inlet system for delivering atmospheric oxygen for combustion with the fuel rich gases generated within the missile and a nozzle exhausts combustion products that result from combustion of the fuel, the liquid and solid oxidizers, and air.

In a general embodiment, a propulsion system and an explosive are integrated into a propulsion section of an artillery round as an integrated propulsion and warhead system. The integrated propulsion and warhead system includes a propulsion system, such as an air-breathing jet engine, and an explosive configured as an annular explosive concentrically arranged around at least a portion of the propulsion system within the propulsion section. The integration of both the propulsion system and the explosive within the propulsion section frees up space in an adjacent guidance section of the artillery round while permitting maximum space allocation for the propulsion volume in the propulsion section of the artillery round.

According to a first aspect of the invention, an integrated propulsion and warhead system for an artillery round, the integrated propulsion and warhead system comprising: a propulsion system; and an annular explosive concentrically arranged around at least a portion of the propulsion system, wherein the propulsion system includes an air-breathing jet engine.

According to another embodiment of any paragraph(s) of this summary, the propulsion system includes a solid rocket motor and an annular, air-breathing jet engine concentrically arranged around at least a portion of the solid rocket motor.

According to another embodiment of any paragraph(s) of this summary, the air-breathing jet engine includes a ramjet.

According to another embodiment of any paragraph(s) of this summary, the air-breathing jet engine includes a scramjet.

According to another embodiment of any paragraph(s) of this summary, the annular explosive includes a high-explosive material.

According to another embodiment of any paragraph(s) of this summary, the integrated propulsion and warhead system further includes an annular insulating member concentrically arranged between the propulsion system and the annular explosive.

According to another embodiment of any paragraph(s) of this summary, the integrated propulsion and warhead system further includes an annular support member concentrically arranged between the propulsion system and the annular explosive.

According to another embodiment of any paragraph(s) of this summary, the annular support member is concentrically arranged around the annular insulating member.

According to another embodiment of any paragraph(s) of this summary, the integrated propulsion and warhead system further includes a housing concentrically arranged around the annular explosive.

According to another aspect of the invention, an artillery round comprising: a housing defining a guidance section and a propulsion section, the propulsion section including an integrated propulsion and warhead system according to the first aspect.

According to an embodiment of any paragraph(s) of this summary, the artillery round includes a nozzle. The guidance section is arranged on a fore end of the propulsion section and the nozzle is arranged on an aft end of the propulsion section.

According to another embodiment of any paragraph(s) of this summary, the housing further defines at least one air inlet for guiding ambient air into the propulsion section.

According to another embodiment of any paragraph(s) of this summary, the artillery round further includes a fuel isolator disposed between the propulsion section and the guidance section.

According to another embodiment of any paragraph(s) of this summary, the artillery round further includes an annular insulating member concentrically arranged between the propulsion system and the annular explosive.

According to another embodiment of any paragraph(s) of this summary, the artillery round further includes an annular support member concentrically arranged around the annular insulating member.

According to another embodiment of any paragraph(s) of this summary, the artillery round further includes a safe and arm device operatively coupled to the annular explosive in propulsion section and configured to control detonation of the annular explosive.

According to another embodiment of any paragraph(s) of this summary, the propulsion system includes a solid rocket motor and an annular, air-breathing jet engine concentrically arranged around the solid rocket motor.

According to another aspect of the invention, a method of assembling an integrated propulsion and warhead system for an artillery round, the method comprising: forming a housing defining a propulsion section; disposing a propulsion system within the propulsion section, wherein the propulsion system includes an air-breathing jet engine; and arranging an annular explosive concentrically around at least a portion of the propulsion system within the propulsion section.

The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages, and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

The annexed drawings show various aspects of the invention.

According to a general embodiment, an artillery round includes an integrated propulsion and warhead system in a propulsion section of the artillery round. The integrated propulsion and warhead system includes a propulsion system and an annular explosive concentrically arranged around at least a portion of the propulsion system within the propulsion section. The integration of both the propulsion system and the explosive within the propulsion section frees up space in an adjacent guidance section of the artillery round while permitting maximum space allocation for the propulsion system and the annular explosive in the propulsion section of the artillery round.

Referring now to the figures, and initially to <FIG>, an exemplary embodiment is depicted of an artillery round <NUM> according to an aspect of the invention. The artillery round <NUM> is configured to be projected or launched from artillery such as, for example, guns, howitzers, mortars and cannons (generally referred to herein as "gun"). The artillery round <NUM> may be used with other types of artillery, as appropriate.

The artillery round <NUM>, having a fore end <NUM> and an aft end <NUM>, includes a housing <NUM> that defines various chambers and parts of the artillery round <NUM>. For example, the housing <NUM> defines a guidance section <NUM> in which various hardware and electronics for controlling the artillery round <NUM> may be housed. Specifically, hardware and electronics such as seeker hardware, navigation sensors, inertial sensors, and processor electronics may be housed in the guidance section <NUM> of the artillery round <NUM>.

The housing <NUM> also defines a propulsion section <NUM> in which an integrated propulsion and warhead system <NUM> is housed. The guidance section <NUM> may be located on the fore end <NUM> of the propulsion section <NUM>. Additionally, a nozzle <NUM> may be arranged on the aft end <NUM> of the propulsion section <NUM>. The nozzle <NUM> may be any suitable type of nozzle for propelling the artillery shell <NUM>.

The integrated propulsion and warhead system <NUM> includes a propulsion system <NUM>, and an annular explosive <NUM> concentrically arranged around at least a portion of the propulsion system <NUM> in the propulsion section <NUM>. For example, the annular explosive <NUM> may be concentrically arranged around the propulsion system <NUM> along a portion of or an entire axial length of the propulsion system <NUM> in the propulsion section <NUM>, and/or even extending past the entire axial length of the propulsion system <NUM> in the propulsion section <NUM>. As used herein, the term "axial length" refers to a length in the axial (i.e., longitudinal) direction, the axial direction extending between the fore end <NUM> and the aft end <NUM> of the artillery round <NUM>.

The annular explosive <NUM> may be, for example, a fragmenting and/or explosive material and may be made of, for example, a high-explosive material. The high-explosive material may include, for example, RDX or HMX formulations such as PBXN-<NUM>, PBXN-<NUM>, PBXN-<NUM>, PBXN-<NUM>. In an embodiment, the annular explosive <NUM> may not include a fragmentation sleeve to save on space and weight of the annular explosive <NUM>. In this embodiment, the housing <NUM> may be made of a fragmenting material at least in a portion of the housing <NUM> that is configured to be concentrically arranged around the annular explosive <NUM> in the propulsion section <NUM>. The housing <NUM>, therefore, may fragment upon detonation of the annular explosive <NUM> at a predetermined target. The portion of the housing <NUM> that is configured to be concentrically arranged around the annular explosive <NUM> in the propulsion section <NUM> may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the portion of the housing <NUM> that is configured to be concentrically arranged around the annular explosive <NUM> has a thickness of <NUM> (<NUM> inches). An optimal thickness of the portion of the housing <NUM> that is concentrically arranged around the annular explosive <NUM> will depend on factors such as setback, balloting, and set forward forces imparted on the housing <NUM> during discharge from the gun, the size of the artillery shell, and desired fragmentation of the housing <NUM> after detonation of the annular explosive <NUM>.

The annular explosive <NUM> may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the annular explosive <NUM> has a thickness of <NUM> (<NUM> inches). An optimal thickness of the annular explosive <NUM> will depend on factors such as critical diameter for detonation, desired fragmentation performance upon detonation, and vulnerability characteristics of the predetermined target to be engaged.

The propulsion system <NUM>, concentrically arranged within the annular explosive <NUM>, is primarily responsible for propelling the artillery round <NUM> after it has been projected or launched from the gun. The propulsion system <NUM> may therefore include a solid rocket motor <NUM> (<FIG>). The propulsion system <NUM> includes an air-breathing jet engine <NUM> (<FIG>). The air-breathing jet engine <NUM> may include one of, for example, a ramjet and a scramjet. Other types of suitable propulsion systems may be applicable to the artillery round <NUM>. The housing <NUM> may be configured to define one or more air inlets <NUM>, for example at a fore end <NUM> of the artillery round <NUM> for allowing ambient air to enter the artillery round <NUM> and reach the propulsion section <NUM> for combustion of the propulsion system <NUM>.

Space allocations within the artillery round <NUM> can be optimized by integrating the explosive member of the artillery round <NUM> as the annular explosive <NUM>. Specifically, the explosive member may be included as part of the integrated propulsion and warhead system <NUM> and may be concentrically arranged around the propulsion system <NUM> in the propulsion section <NUM>. In this way, allocating space for the explosive member in the guidance section <NUM> or elsewhere toward the fore end <NUM> of the artillery round <NUM>, as conventionally done in the development of extended range artillery munition, is not necessary. This preserves space in the guidance section <NUM> for allocation to various control hardware and electronics, while permitting a maximum length of the propulsion section <NUM> and, in particular, the propulsion system <NUM> in the propulsion section <NUM>. This optimizes the extended range at which the propulsion system <NUM> can propel the artillery round <NUM> after it has been projected or launched from the gun. Additionally, as the annular explosive <NUM> may extend up to an entire length of the propulsion section <NUM>, the size and effectiveness of the annular explosive <NUM> in the artillery round <NUM> may also be optimized.

<FIG> depicts an exemplary embodiment of the artillery shell <NUM> in which the propulsion system <NUM> includes both the solid rocket motor <NUM> and the air-breathing jet engine <NUM>. The air-breathing jet engine <NUM> is configured to be an annular air-breathing jet engine <NUM> and is concentrically arranged around at least a portion of the solid rocket motor <NUM>. For example, the air-breathing jet engine <NUM> may be concentrically arranged around the solid rocket motor <NUM> along a portion of or the entire axial length of the solid rocket motor <NUM> in the propulsion section <NUM>, and/or even extending past the entire axial length of the solid rocket motor <NUM> in the propulsion section <NUM>. In this embodiment, the annular explosive <NUM> is concentrically arranged around the propulsion system <NUM>, particularly the air-breathing jet engine <NUM>, in the same way as previously described with respect to the embodiment depicted in <FIG>.

The solid rocket motor <NUM> may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the solid rocket motor <NUM> has a thickness of <NUM> (<NUM> inches). An optimal thickness of the solid rocket motor <NUM> may depend on factors such as the desired range of the artillery round <NUM>, the minimum temperature at which the round must operate, the gun launch conditions, and the mechanical properties of the rocket propellant.

The ramjet fuel of the air-breathing jet engine <NUM> may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the ramjet fuel of the air-breathing jet engine <NUM> has a thickness of <NUM> (<NUM> inches). An optimal thickness of the ramjet fuel of the air-breathing jet engine <NUM> may depend on factors such as the desired range of the artillery round, the level of thrust that the engine needs to produce to overcome drag and deceleration, the minimum temperature at which the round must operate, the gun launch conditions, and the mechanical properties of the fuel.

<FIG> depicts a further exemplary embodiment in which additional features are included in the integrated propulsion and warhead system <NUM> of to any one of the previously described embodiments. For example, the integrated propulsion and warhead system <NUM> may additionally include an annular insulating member <NUM> concentrically arranged between the propulsion system <NUM> and the annular explosive <NUM> for insulating the fuel of the propulsion system <NUM> and the heat that is produced as it combusts, from the annular explosive <NUM> so that the annular explosive <NUM> does not detonate prematurely. The annular insulating member <NUM> may be, for example, EPDM (ethylene propylene diene monomer rubber), DC93-<NUM> or other rocket and ramjet high performance insulator materials. The annular insulating member may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the annular insulating member has a thickness of <NUM> (<NUM> inches). An optimal thickness of the annular insulating member will depend on factors such as temperature of the propulsion fuel during flight and heat tolerance of the warhead materials. The annular insulating member is designed to be the minimum thickness required to retard heat transfer sufficient for proper operation of the warhead. The annular insulating member <NUM> is configured to be concentrically arranged around the propulsion system <NUM> along an entire axial length of the propulsion system <NUM> or even extending past an entire axial length of the propulsion system <NUM>.

The integrated propulsion and warhead system <NUM> may additionally include an annular support member <NUM> concentrically arranged between the propulsion system <NUM> and the annular explosive <NUM> for adding additional structural support to the annular explosive <NUM> and adding an additional structural layer of separation between the propulsion system <NUM> and the annular explosive <NUM>. The annular support member <NUM> may be aluminum, steel, or other metal or non-metal. The annular support member <NUM> may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the annular support member <NUM> has a thickness of <NUM> (<NUM> inches). An optimal thickness of the annular support member <NUM> will depend on factors such as forces encountered during gun launch, fragmentation performance considerations, and/or performance trades depending on thicknesses of other concentric components. The annular support member <NUM> may be, for example, concentrically arranged around the annular insulating member <NUM> and may extend along an entire axial length of the annular insulating member <NUM> or even extend past an entire axial length of the annular insulating member <NUM>.

The artillery round <NUM> may include a fuel isolator <NUM> disposed between the propulsion section <NUM> and the guidance section <NUM> for isolating the components in each chamber from each other. The fuel isolator <NUM> may be, for example, silica phenolic. The fuel isolator <NUM> may have a thickness in the range of <NUM> to <NUM> (<NUM> inches to <NUM> inches), <NUM> to <NUM> (<NUM> inches to <NUM> inches), or <NUM> to <NUM> (<NUM> inches to <NUM> inches). In an embodiment, the fuel isolator <NUM> has a thickness of <NUM> (<NUM> inches). An optimal thickness of the fuel isolator will be sized to retard heat loss into the guidance section <NUM>, while withstanding gun launch loads. The artillery round <NUM> may additionally include a safe and arm device <NUM> in the guidance section <NUM> operatively coupled to the annular explosive <NUM> in the propulsion section <NUM>, as depicted by the dotted line <FIG>. The safe and arm device <NUM> is configured to control detonation of the annular explosive <NUM>.

With reference to <FIG>, a method <NUM> is depicted of assembling an integrated propulsion and warhead system (such as the integrated propulsion and warhead system <NUM> of <FIG>), for an artillery round (such as the artillery round <NUM> of <FIG>). The method <NUM> includes the step <NUM> of forming a housing defining a guidance section and a propulsion section (such as the guidance section <NUM> and the propulsion section <NUM> in <FIG>).

The method <NUM> then includes the step <NUM> of disposing a propulsion system (such as the propulsion system <NUM> of <FIG>) within the propulsion section of the housing. A step <NUM> of arranging an annular explosive (such as the annular explosive <NUM> of <FIG>) concentrically around at least a portion of the propulsion system is then provided. The step <NUM> of disposing and the step <NUM> of arranging may be performed in any order. For example, the step of arranging <NUM>, when performed before the step <NUM> of disposing, may include arranging the annular explosive within the propulsion section of the housing, and the step <NUM> of disposing may then include disposing the propulsion system within the annular explosive in the propulsion section such that the propulsion system is arranged concentrically within the annular explosive.

With reference to <FIG>, a method <NUM> of detonating an artillery round (such as the artillery round <NUM> of <FIG>) is depicted. The method <NUM> includes the step <NUM> of discharging the artillery round from an artillery gun at an initial velocity. The artillery round includes an integrated propulsion and warhead system (such as the integrated propulsion and warhead system <NUM> of <FIG>). Specifically, the integrated propulsion and warhead system includes a propulsion system having a solid rocket motor and an annular air-breathing jet engine concentrically arranged around at least a portion of the solid rocket motor (such as the configuration of the propulsion system <NUM> of <FIG>). The integrated propulsion and warhead system also includes an annular explosive concentrically arranged around at least a portion of the propulsion system (such as the annular explosive <NUM> of <FIG>).

The method <NUM> further includes the step <NUM> of igniting the solid rocket motor to maintain or increase the initial velocity of the artillery round after discharge from the gun and to propel the artillery round until the solid rocket motor is depleted. When initially discharged from the gun, the artillery round must first travel through thick atmosphere. The solid rocket motor, therefore, is ignited to propel the artillery round through this thick atmosphere. Once the solid rocket motor is depleted, ambient air reaches the air-breathing jet engine to ignite and burn the air-breathing jet engine fuel. The method <NUM> further includes the step <NUM> of igniting the air-breathing jet engine after depletion of the solid rocket motor to further propel the artillery round until it reaches a predetermined target. Typically, by the time the air-breathing jet engine is ignited, the artillery round will be in thinner atmosphere, compared to when it was first discharged from the gun. Accordingly, the air-breathing jet engine is ignited to further propel the artillery round through the thinner atmosphere, until it reaches the predetermined target. The method <NUM> then further includes the step <NUM> of detonating the annular explosive when it reaches the predetermined target.

Claim 1:
An integrated propulsion and warhead system (<NUM>) for an artillery round (<NUM>), the integrated propulsion and warhead system comprising: a propulsion system (<NUM>); and an annular explosive (<NUM>) concentrically arranged around at least a portion of the propulsion system, wherein the propulsion system includes an air-breathing jet engine (<NUM>).