Qinetiq Limited

Schlumberger Canada Limited

John Cook

Lakshman Chandrasekaran

Michael John Hinton

Abdul-Salam Kaddour

Noel J Parratt

Nicholas Savage

The invention provides rupturing devices for mitigating the explosive reaction of a casing (), hollow tubular body or container, particularly a munition, when it is subject to an external thermal hazard threat. The devices are based on the use of shape memory alloys. The device comprises an element of shape memory alloy () which is joined together by a connector () to form an annulus, which may be located on an exterior surface of a munitions casing () or launch such that upon heating through its transition temperature range will cause the annulus to contract radially inwardly, thereby rupturing the munition (), allowing any build up of pressure to be released quickly. Advantageously, the connector () is. reversible such that the device will be capable of being retro-fitted or removed during normal servicing of the munition ().

Rupturing devices

A munitions casing including an annulus of a shape memory alloy disposed around said casing where the shape memory alloy has been subjected to a combination of mechanical and thermal treatments so as to impart a memory, and a cutter located between the annulus and the casing wherein heating of the shape memory alloy to a predetermined temperature causes said annulus to contract radially inwardly and rupture the said munitions casing.

Temperature responsive safety devices for munitions

A sabothaving a rearward end and a central longitudinal channelwhich is engageable with projectilehas an anisotropic compressive strength distribution such that on individual radial planes the compressive strength in a first principal material direction Pradiates from the central channeltowards the rearward end of the sabot. This permits a more even distribution of force at the interface between the sabot and the penetrator. The sabot may be constructed from a fibre reinforced plastic composite, containing a single or a double array of fibres.

Sabot

The invention comprises devices for mitigating the explosive reaction of a munition when it is subject to an external thermal hazard threat. The devices are based on the use of shape memory alloys. In one arrangement there is device which consists of a connector that is at least in part formed from a shape memory alloy, which typically undergoes large dimensional changes when heated or cooled through a particular transition temperature range. The connector in this invention is designed to form a locking engagement, between two components of a munitions casing at one temperature, but when subjected to external heating through the transition temperature range will deform to allow the connector to disengage and thus release the two joined components, allowing any build up of pressure to be released quickly. Advantageously if the co-operative parts of the connector and components are threaded portions, then the locking engagement will be capable of being dismantled during normal servicing of the munition. The co-operative parts of the connector may be integral with the components to be connected. In another arrangement the device is an annulus and is located around a munitions casing such that upon heating through its transition temperature range will cause the annulus to contract, thereby rupturing the munitions casing, allowing any build up of pressure to be released quickly.

A method of generating force between a structure and an additional member, particularly for reinforcing an existing structure so that an additional member can share existing load. Pre-cooled or pre-heated shims of shape memory alloy (SMA) are inserted between the additional member and the existing structure, or between different sub-units of the additional member, or between the additional member and shoes fixed for this purpose to the existing structure. On subsequent warming or cooling the SMA shims expand to apply compressive forces to the portions of the structure, additional member or shoe(s) with which they are in contact on their opposite sides. Further compressive, tensile, flexural or torsional forces will be developed within other parts of the structure and additional member as a result of the shim expansion depending on the particular arrangement. Alternatively the SMA may be of a type which expands when warmed above ambient temperature and remains in the expanded state despite cooling back to ambient.

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Sevenoaks, United Kingdom

John Cook