AIR COUNTERMEASURE CARTRIDGE

AIR COUNTERMEASURE CARTRIDGE

Field of the Invention

The invention relates to air countermeasure cartridges and in particular to multishot countermeasure cartridges.

Problem to be solved

Current Air Countermeasure devices comprise one or two payload devices, which are jettisoned from a dispenser mounted on a flying platform. The jettisoned payload(s) becomes a decoy to the seeker head of an Infra-red heat seeking missile providing a more attractive Infra-red source. The jettisoned payload(s) may also be in the form of Chaff for use as a Radar Countermeasure.

Air Countermeasure dispensers are typically located on an air platform in close proximity to the platform's exhaust vents, as they emit the most heat. A typical dispenser has a magazine, which contains an array of up to 30 Countermeasure cartridges or more. When all the Countermeasure cartridges have been fired, the air platform has no means to counter a threat from a heat seeking missile. Therefore, the air platform may have to prematurely leave the hostile environment/theatre, as the risk to the platform and ordinance may be too great. The maximum number of countermeasure cartridges available for protecting the air frame is determined by the physical size of the dispenser and associated magazine.

Current multi-payload Countermeasure devices have a maximum inventory of two payloads. Multi-payload Countermeasure devices also require a dedicated interface for connecting to a dispenser, which is not compatible with conventional single payload countermeasure devices. Current multi-payload devices have a fixed predetermined time period between the dispensing of each payload, which cannot be changed to provide a more effective timing sequence required for known missile threats.

The present invention seeks to provide a remedy to these problems.

Summary of the Invention

In a first independent aspect, the invention provides a countermeasure cartridge comprising a plurality of payloads and a timer disposed within said cartridge; wherein said timer initiates the dispensing of the payloads sequentially and each payload is dispensed automatically after a predetermined time period has lapsed.

This configuration is particularly advantageous because the countermeasure cartridge will incorporate an increased inventory of countermeasure payloads. The inventory of the cartridge may be increased by a factor of (X2), (X4), (X6) or (X8), therefore enabling a 30 cartridge dispenser to dispense 60, 120, 180 or 240 countermeasure payloads. The increased countermeasure inventory enables the air platform to remain within a hostile environment/theatre for a prolonged duration, as there are more counter measure payloads to draw from when confronted by one or more heat seeking missile threats.

Preferably the predetermined time period between the dispensing of the countermeasure payloads is adjustable, so that the most effective firing sequence (also known as the firing pattern), may be dispensed in response to a known heat seeking missile threat. There is no firing pattern, with fixed time periods, which is effective against all heat seeking missile threats.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, there are a plurality of Squibs wherein each Squib is disposed adjacent a respective one of said payloads.

This configuration is particularly advantageous because it enables the payloads to be dispensed independently from the cartridge in a sequence which fires the top payload first and the bottom payload last, i.e. in a top - down firing sequence.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, there are a plurality of electrical charge storage devices wherein each electrical charge storage device is disposed adjacent a respective one of said Squibs.

This configuration is particularly advantageous because it provides a load for an electrical charge to initiate the detonation of the adjacent squib.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, each of said electrical charge storage devices in an active state draws an electrical charge originating from said timer through a portion of wire disposed within said Squib and consequentially said wire heats to a predetermined temperature and initiates said Squib; and in an inactive state does not draw an electrical charge through said wire.

This configuration is particularly advantageous because the electrical charge drawn through the squib and heats up a portion of wire, which ruptures and ignites the main charge within the Squib. The detonation of the Squib independently dispenses the payload from the countermeasure cartridge.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, said timer is disposed at or adjacent one end of said cartridge. This configuration is particularly advantageous because it provides the maximum storage space within the countermeasure cartridge for containing multiple payloads and their associated sub-assemblies.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, there is a plurality of conductors, wherein each conductor communicates a signal from said timer to an associated electrical charge storage device.

This configuration is particularly advantageous because it provides a path for

communicating the firing pulse from the timer to a predetermined payload, which is isolated from all other payloads contained within the Countermeasure cartridge and therefore preventing other payloads from being unintentionally dispensed from the cartridge.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, said timer stores signals which substantially represent a predetermined time period whilst said cartridge is disposed within a countermeasure dispenser.

This configuration is particularly advantageous because it eliminates the requirement of removing all countermeasures from the dispenser system and resetting them individually which is a time consuming operation.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, said payloads are contained within said cartridge in a tandem configuration.

This configuration is particularly advantageous because it removes any payloads which have failed to be dispensed from the countermeasure cartridge, by dispensing the next subsequent payload that pushes itself and any previous unfired payload out of the cartridge. Another advantage of this configuration is that each payload is isolated and are partitioned by partitioned to prevent them from interacting with each other whilst within the countermeasure cartridge.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, the interface between said cartridge and a countermeasure dispenser is via a two or more pin connector.

This configuration is particularly advantageous because it enables the countermeasure cartridge to be fitted and interfaced with existing dispenser systems, which dispense the more conventional single payload countermeasure cartridge.

In a subsidiary aspect in accordance with the invention's first broad independent aspect, a controller is disposed within said cartridge, which is interrogated, in use, by a system external to said cartridge, wherein said controller communicates the configuration of said configuration to said cartridge to said system.

This configuration is particularly advantageous because it enables the countermeasure cartridge to dynamically communicate its inventory to the dispenser system.

In a second independent aspect the invention provides a system for dispensing a plurality of payloads from a countermeasure cartridge comprising:

• Means for storing signals within said cartridge which substantially represents a predetermined time period;

• Means for monitoring if said pre-determined time period has lapsed;

• Means for communicating a signal which substantially represents the initialisation of a payload dispensing means after said predetermined time period has lapsed; and

• Means of interfacing with said cartridge to said system;

• Whereby said cartridge initiates the dispensing of a payload after a predetermined time period has lapsed. In a subsidiary aspect in accordance with the invention's second broad independent aspect, the next payload within said cartridge is automatically dispensed when said system detects a payload that has failed to dispense from said cartridge.

In a third independent aspect the invention provides a method for dispensing a plurality of payloads from a countermeasure cartridge comprising the steps of:

• Storage signals from said cartridge which substantially represent a pre-determined time period;

• Monitoring if said pre-determined time period has lapsed;

• Communicating a signal to a payload dispensing means which substantially represents the initialisation of a payload after said predetermined time period has lapsed; and

• Interfacing said cartridge to said system.

In a subsidiary aspect in accordance with the invention's third broad independent aspect, there is included the step of dispensing automatically the next payload within said cartridge when a payload has failed to dispense from said cartridge.

Brief Description of the Figures

Figure 1 shows a cross-sectional view of the preferred embodiment of the invention which incorporates four Countermeasure payloads.

Detailed Description of the Figures

Figure 1 shows the preferred embodiment of the invention, in which a Countermeasure cartridge is generally indicated by 1. The Countermeasure cartridge 1 is shown to be positioned vertically along axis AA and is substantially similar to the known "118 Countermeasure cartridge type". The cartridge 1 incorporates four independent

Countermeasure payloads 2, 3, 4 and 5, which are stacked on top of each other in a tandem configuration, payload 2 being the lowest payload and payload 5 being the highest payload within the configuration. An interface portion 6 is located at the bottom end of the Countermeasure cartridge 1 for connecting and interfacing the cartridge 1 to a

Countermeasure dispenser (not shown). The interface portion 6 incorporates a central contact pin 7, which is disposed within a central recess 8 in the lower outer surface of interface portion 6. The interface portion 6 also incorporates an annular contact portion 9, which is insulated from the central contact pin 7 by an insulating portion 10. The interface portion 6 is integral to the outer body of the cartridge 1. Central contact pin 7 is held centrally by insulator 10. An annular cavity 11 is located about contact pin 7. The central contact pin 7 and annular contact portion 9 are electrically connected to a printed circuit board 12, by electrical conductors (not shown). The capacitors 13 are attached to printed circuit board 12 and in the present design are inverted.

The printed circuit board 12 incorporates an electrical connector 14, which mates with an electrical connector 15 that is attached to the lower end of an electrical interconnecting loom 16. The interconnecting loom 16 extends vertically adjacent to Countermeasure payload 2 and is connected to a second electrical connector 14a at its upper end. The upper connector 14a is connected to the lower connector 15a of a second interconnecting loom 24, which extends vertically adjacent to Countermeasure payload 3 and is connected to a second electrical connector 14b at its upper end. The upper connector 14b is connected to the lower connector 15b of a third interconnecting loom 25, which extends vertically adjacent to Countermeasure payload 4 and is connected to a second electrical connector 14c at its upper end. The upper connector 14c is electrically connected (not shown) to the fuse head 17d dedicated to payload 5. The electrical interconnecting looms 16, 24 and 25 are typically formed from ribbon cables, which are attached to inline plug and sockets. The interconnecting loom 16 carries the firing pulses for payloads 3, 4 and 5, interconnecting loom 24 carries the firing pulses for payloads 4 and 5, and

interconnecting loom 25 carries the firing pulse for payload 5.

Each Countermeasure payload 2, 3, 4 and 5 has a dedicated fuse head device 17a -d. Each fuse head device 17a -d is centrally located in a cavity, incorporated within the upper surface of a seal plate assembly 18 a -d. Each Countermeasure payload 2, 3, 4 and 5 has a dedicated seal plate assembly 18 a -d, which extends across the inner cavity of the cartridge 1. Seal plate assembly 18a houses a fuse head device 17a, which initiates payload 2. Seal plate assembly 18a incorporates the electrical connections (not shown) from the printed circuit board 12 to fuse head device 17a. Seal plate assembly 18b houses a fuse head device 17b, which initiates payload 3. Seal plate assembly 18b incorporates the electrical connections (not shown) from electrical interconnecting loom 16 to fuse head device 17b. Seal plate assembly 18c houses a fuse head device 17c, which initiates payload 4. Seal plate assembly 18c incorporates the electrical connections (not shown) from electrical interconnecting loom 24 to fuse head device 17c. Seal plate assembly 18d houses fuse a head device 17d, which initiates payload 5. Seal plate assembly 18d incorporates the electrical connections (not shown) from electrical interconnecting loom 25 to fuse head device 17d.

Each seal plate assembly 18a -d incorporates a seal 19 about its peripheral edge, which extends in an upwards direction and abuts the face of the inner cavity of the cartridge 1 , and a fuse head 17a -d, which is coated with an initiating charge, and is retained within the seal plate assembly 18a -d, via an adhesive disk (not shown). The fuse head 17a -d initiates the initialising charge and therefore ejects the payload 2, 3, 4 and 5 from the Countermeasure cartridge 1. Furthermore, each seal plate assembly 18a -d incorporates an electrical connector 14, 14a -c which connects to the shutter plate assembly 21a -d.

Each fuse head 17a -d is adjacently positioned to a take-over cup insert 28. A take-up charge is incorporated within the lower surface of the take-over cup insert 28. The take- up charge 20 is connected to a take-over charge 29, incorporated within the upper surface of the take-over cup insert 28, via a connecting conduit 30, which also contains a charge. A take-over cup insert 28 is incorporated within the lower surface of each take-over cup assembly 21a -d.

Each take-over cup assembly 21a -d incorporates a shutter plate assembly 22 which is biased in a rightward direction by two springs (not shown). The shutter assembly 22 incorporates an aperture 23, which when activated is aligned with apertures 31 and 32 to allow the communication of hot gases from the take-over charge 29 to the

Countermeasure payload 2, 3, 4 and 5. The upper surface of seal plate assembly 18a abuts the lower surface of take-over assembly 21a. The upper surface of seal plate assembly 18b abuts the lower surface of take-over assembly 21b. The upper surface of seal plate assembly 18c abuts the lower surface of take-over assembly 21c. The upper surface of seal plate assembly 18d abuts the lower surface of take-over assembly 2 Id. The abutment of each seal plate assembly to a take-over assembly forms a barrier, which extends across the inner cavity of the cartridge 1. The barrier isolates the other payloads shared within the cartridge from the hot gases which are present when a payload is dispensed.

A capping member 27 is inserted into the top end of the countermeasure cartridge 1 to retain the countermeasure payloads 2, 3, 4 and 5 in a tandem configuration, within the cartridge 1

Each payload 2, 3, 4 and 5 incorporates a take-over cup assembly 21a -d, seal plate assembly 18a -d, an electrical interconnecting loom 16, 24 and 25 and electrical connectors 14a -d and 15a -d. Each Countermeasure payload 2, 3, 4 and 5 is held between a top plate assembly 21a -d and the seal plate assembly 18a -d, and are held in place by an adhesive foil wrap. The top payload 5 does not require a sealing plate. Seal plate assembly 18a, which abuts the printed circuit board 12, contains the ejection charge for the lowest payload 2. The composition of each Countermeasure payload 2, 3, 4 and 5 and its associated sub-assemblies is identical in regards to the assembly of the cartridge 1.

In use, the Countermeasure cartridge 1 is contained within a magazine, which is subsequently attached to a Countermeasure dispenser located on an aircraft platform. The Countermeasure cartridge 1 receives an initial firing pulse from the dispenser to initiate the dispensing of the Countermeasure payloads contained within the cartridge 1. The initial firing pulse is received via the central contact pin 7 and outer contact portion 9, and is then communicated to the printed circuit board 12, via internal electrical conductors (not shown). The printed circuit board 12 incorporates four capacitors, three of which store the electrical charges required for generating the subsequent firing pulses after the initial firing pulse from the dispenser, and a fourth capacitor for storing the charge for powering the printed circuit board 12. The firing pulse to payload 5 is communicated by interconnected looms 16, 24 and 25. The firing pulse to payload 4 is communicated by interconnected looms 16 and 24. The firing pulse to payload 3 is communicated by interconnection loom 16. The firing pulse to payload 2 is communicated via a dedicated connection to the printed circuit board 12.

The printed circuit board 12 incorporates various electronic devices which control, time, switch and distribute the electrical charges within the cartridge 1. Central to this functionality is a timer device, such as a Programmable Integrated Circuit (PIC), which controls the timing, duration and number of firing pulses. The programming of the predetermined time period is undertaken when the PIC is outside the containing case of the cartridge 1. (At present it is not possible to reprogram the timing device through the two pin connector, however this may be possible with a multi pin connector or digital interface, but this would entail changes to the aircraft's electronics/systems). The Printed circuit board 12 also incorporates a safety device, which discharges the incorporated capacitors after a predetermined time period has lapsed. The printed circuit board 12 is not capable of detecting a payload ejection failure, but the subsequent payload will eject any previous payload, which has failed to eject from the cartridge. For example, if the final payload within the cartridge 1 has failed to eject, the safety device will then ensure that there was no electrical charge within the capacitors to prevent the initiation of the payload.

The firing sequence of the Countermeasure payloads 2, 3, 4 and 5 incorporated within the cartridge 1 starts from the top most payload 5 and finishes at the bottom most payload 2. The initial firing pulse from the Countermeasure dispenser initiates the firing of payload 5. The timer device located within the PC, then subsequently communicates a sequence of mutable firing pulses to Countermeasure payloads 2, 3 and 4. The four firing pulses to Countermeasure payloads 2, 3, 4 and 5 are spaced apart by a predetermined time period (typically ranging from 0 to 6 seconds). The predetermined time period is programmed into the timer device incorporated on the printed circuit board 12. The initial firing pulse from the dispenser charges the four capacitors on board the printed circuit board 12 and initiates the firing of the first payload 5 from the cartridge 1. The printed circuit board 12 routes subsequent firing pulses to other Countermeasure payloads 2, 3 and 4 in accordance with the programmed firing sequence. Each firing pulse is applied to a dedicated fuse head device 17a -d for each payload 2, 3, 4 and 5. Each fuse head 17a -d draws a charging current from the associated firing pulse, which causes it to heat and rupture. The rupturing of the fuse head 17a -d ignites the initialising charge, which is located about the fuse head 17a -d. The ignition of the initiating charge forces the Countermeasure payload 2, 3, 4 and 5, along with its associated seal plate and takeover cup assemblies, out of the cartridge 1.

The ignition of the initialising ignites the take-up charge 20. The take-up charge 20 then subsequently ignites the charge within the connecting conduit 30. The charge within the connecting conduit 30 will burn for a predetermined time period. The predetermined time period is dependent upon the time taken for burning the charge contained within connecting conduit 30, for example the burn time is dependent upon length and/or width of the connection conduit 30. The connecting conduit 30 communicates the burning charge from the take-up charge 20, to the take-over charge 29. After the payload 2, 3, 4 and 5 has exited the Countermeasure cartridge 1, the shutter assembly 22 opens to allow the communication of hot gases from the take-over charge 29 to the Countermeasure payload 2, 3, 4 and 5 via the alignment of apertures 23, 31 and 32. The communication of hot gases, generated by the burning take-over charge, initiates the burning of the payload 2, 3, 4 and 5.

The peripheral seal 19 of the seal plate assembly 18 ensures that any flame from the ejection charge does not reach the countermeasure payload 2, 3, 4 and 5 below. Also, the peripheral seal 33 of the take-over device 21a -d contains the pressure generated by the initialisation of the ejection charge. The take-over cup assembly 21a -d is also known as the "Safe and Arm" device.

When a countermeasure payload 2, 3, 4 and 5 fails to exit the cartridge 1, it is classed as a "misfire". When a misfire occurs, the successful deployment of the next payload will also jettison any previously misfired payloads from the cartridge 1. For example, the cartridge 1 will deploy the bottom most payload 2 if there have been three consecutive misfires. Therefore, by jettisoning the three previously misfired payloads 3, 4 and 5 which are stacked in a tandem configuration, the Countermeasure cartridge 1 is therefore emptied of all its payloads 2, 3, 4 and 5.

The cartridge 1 is intended for use with known dispenser systems by interfacing with a dispenser via the standard two-pin configuration.

The payloads are assembled into interchangeable modules which are assembled within the casing of the Countermeasure cartridge 1. The compositions of the interchangeable modules are typically of a flare type. Therefore, the Countermeasure payloads 2, 3, 4 and 5 within a Countermeasure cartridge 1 may be flare payloads with various temperature spectrums. Combinations of flare and Chaff payload modules may be contained within the Countermeasure cartridge 1 to provide a firing pattern, which contains both chaff and flare Countermeasures. The payload modules provide a method the assembling a

Countermeasure cartridge, which is configurable to counter a specific missile threat.

Each payload module is self contained and is directly connectable to other payload modules to form Countermeasure devices, which deploy various payload combinations for specific threats. Each module incorporates a self contained means of initiating the payload. Each payload module incorporates a payload sandwiched between an upper seal plate assembly and a lower take-over cup assembly. The payload is wrapped in a foil/membrane to contain it between the two assemblies. Once the payload modules have been assembled into the Countermeasure cartridge, they are electrically daisy chained together via interconnecting looms. When a payload is jettisoned from the cartridge, it is ejected along with its associated subassemblies, therefore remove any trace of the previously fired payload. The interconnecting looms and their associated connectors provide a quick method of electrical separation of the payload modules. In an alternative embodiment of the invention, the printed circuit board 12 is mounted in close proximity to central contact pin 7. The capacitors are mounted are mounted in close proximity to seal plate assembly 18 a.

In an alternative embodiment of the invention, the programming of the predetermined time period is undertaken when the Countermeasure cartridge 1 has been loaded on to a Countermeasure dispenser.