EP3746735B1

EP3746735B1 - Weapon delivery system

Info

Publication number: EP3746735B1
Application number: EP19702691.7A
Authority: EP
Inventors: Nicholas Charles CORNER; Anthony Edward MARSH; Robert David BAKER
Original assignee: Portsmouth Aviation Ltd
Current assignee: Portsmouth Aviation Ltd
Priority date: 2018-02-02
Filing date: 2019-01-24
Publication date: 2021-12-22
Anticipated expiration: 2039-01-24
Also published as: EP3746735A1; SA520412555B1; GB2577028A; WO2019150080A1; GB201801743D0

Description

Technical Field

The present invention relates generally to weapon delivery systems, and in particular to aerial bomb arming arrangements.

Background

Weapon delivery systems are known for the deployment of aerial bombs. In such arrangements, the system ensures that the bomb is only armed once it has left the aircraft. In this process, the bomb undergoes an arming sequence. This is known to include a wind/air arming device, which includes turbine blades/vanes which are arranged to rotate when exposed to the atmosphere, and thereby generate an electrical current (which in possible conjunction with one or more other signals) causes the bomb to be armed. This may be termed a mechanical or electro-mechanical arming environment.
In addition, to ensure safe arming (i.e. the bomb is not armed whilst still on board the aircraft) there is also a second, electrical, arming environment. This is known to be by way of a Lead Electrical Fuze Arming (LEFA) electrical pulse, which is generated from the aircraft to the fuze of the bomb, upon a release bomb signal. More specifically, the LEFA pulse, is generated at the moment of bomb release that is conditional upon the mechanical unlocking of the aircraft's bomb release unit and hence the separation of the bomb from the aircraft.
With the bomb unarmed, the air-driven arming device is held in a stowed condition, not exposed to the surrounding atmosphere. When the bomb needs to be armed, a lanyard, at one end fixed to the airframe (or at least in the frame of reference) of the aircraft and the other to the device, applies a pulling force to bring the arming device into a deployed condition. However, for different aircraft and different bomb types/manufacturers, the lanyard fixation point is not always located at the optimal position relative to the position of the arming device so as to urge the arming device into a deployed condition.
A known bomb arming assembly is disclosed in US4882970 which is arranged to be located externally of the bomb.
We seek to provide an improved weapon delivery system for aerial bombs.

Summary

According to the invention there is provided an aerial bomb arming assembly, which comprises an air driven turbine, which is arranged to rotate and generate an electrical current when exposed to atmosphere, and the turbine arranged for transition from a stowed condition to a deployed condition, and the assembly further comprising a lever arm which comprises a first end, a second end and an arm portion, and the first end is connected to the arm portion by way of a pivotable connection, and the first end is arranged for translational movement along a guide, and the second end of the arm portion arranged to provide a pulling force to the device when the first end translates on the guide, wherein the first end is arranged to be located within the internal space of the bomb, which internal space is defined within an outer casing.
Transition from the stowed condition to the deployed condition may comprise exposing the turbine to atmosphere.
The turbine may be arranged in a space which is provided with a cover or top, and the cover arranged to be removed or repositioned by way of the pulling force provided by the (lever) arm portion, so as to expose the arming turbine.
The pivotable connection between the first end and the arm portion preferably allows the arm portion to pivot relative to the first end.
The guide may comprise a rod, rail or shaft.
The guide may extend substantially parallel to the longitudinal axis of the bomb.
The second end of the arm may be arranged to protrude externally of the outer casing or housing of the bomb, at least when in a deployed or in-use condition.
The air driven turbine may comprise an alternator or a solenoid, arranged to generate an electrical current or pulse when rotation of the turbine occurs.
By the expression 'arming of an aerial bomb' we include the meaning of the fuze of the bomb being armed/operational.
'Aerial bomb' may also be described as an aerially deployed munition.
For the avoidance of doubt, by 'rod' we include any elongate member, which need not necessarily have a circular or round cross-section.
The arming assembly may comprise a lanyard, one end portion of which is arranged to be attached to a fixation point fast with an aircraft, and another end portion of the lanyard may be secured to the lever arm so as, in use, to pull the first end along the guide.
Said other end portion of the lanyard may be secured to the first end of the lever arm.
'Lanyard' may include a cord, a wire or a cable.
The invention may include one or more features described in the description and/or shown in the drawings, either individually or in combination.

Brief Description of the Drawings

Various embodiments of the invention will now be described, by way of example only, with reference to the following drawings in which:

Figure 1 is a perspective view of an aerial bomb arming device,
Figure 1A is an enlarged view of part of Figure 1,
Figure 2 is a reverse angle perspective view of the aerial bomb arming device of Figure 1,
Figure 2A is a side view of a lever arm of the arming device of Figure 2,
Figure 3 a plan view of the aerial bomb arming device of Figure 1,
Figure 4 is an enlarged view of part of the lever arm of Figures 1 and 2,
Figure 5 shows a side view of an aerial bomb attached to an aircraft structure, and
Figure 6 is a further version of the view shown in Figure 2 in which the arming device is in a deployed condition.

Detailed Description

Reference is made to Figure 1 which shows the innards of an aerial bomb 1, with particular emphasis on its (mechanical) arming environment. The aerial bomb comprises explosive material, a fuze and an arming device. It will be appreciated that in the view shown, an outer casing of the bomb is omitted for reasons of clarity. (However, structural rings 50 are shown to provide an indication of the internal volume of that section of the bomb.)
The arming device 2 comprises a bladed/vaned turbine which is contained within a pivotably mounted housing 2 (as best seen in Figure 6). The housing 2 is located, in an undeployed condition, in a void provided by the device 3 and which is covered by a removable cover 4.
The cover 4 comprises fixing points 5a and 5b provided on its outer surface, to which portions of a lanyard 10 are attached. The cover 4 is arranged to be capable of being peeled away from the housing of the arming device 2, and pivot the turbine contained in the housing 2 outwardly so as to operationally expose the underlying turbine.
The (mechanical) arming environment further comprises a lever arm 12, which comprises a first end 13a and a second end 13b, and the first end and the second end are provided at distal/extreme ends of an arm portion 14. A pivot 15 is provided to pivotably connect the arm portion 14 to the first end 13a.
The first end 13a comprises a substantially cylindrical part, open at both ends, which receives through its internal space a guide shaft 20. A bearing 21 is provided on the inwardly facing region of the first end, which bearing contacts with the guide shaft 20. As will be described in more detail below, the first end 13a is arranged to slide or translate along the guide shaft 20. The guide shaft 20 is substantially parallel to a longitudinal axis of the bomb. One end of the guide shaft 20 is supported in a transverse/cross beam member 16 by way of a shaft end support 23.
The lever arm 12 comprises a fixing point within the end portion 13a for an end portion of a lanyard 30, as best seen in Figure 4. A reinforced eye 30b is secured by a pin 22, which pin passes through two upright flanking formations 13c. The lanyard 30 runs from the first end 13a through a through hole provided in the shaft end support 23 attached to cross-beam 16, and outwardly through an aperture 31. An opposite distal end of the lanyard 30 comprises a reinforced eye 30a. The eye 30a, the use of which is described further below, is arranged to be secured or connected (directly or indirectly) to a fixture which is fast with the aircraft, such as the superstructure or airframe of the aircraft, such as a hook.
The second end 13b of the lever arm 14 comprises a lanyard guide surface 18 (seen best in Figure 3). This surface advantageously serves to correctly position and centralise the lanyard 10 so that a pulling force is applied at the correct orientation/position.
That part of the arm portion 14 which is adjacent to the second end 13b, extends/protrudes through an aperture 19, and externally of the outer casing of the bomb during arming.
The lanyard 10 is secured to the arm portion 14 by way of the rigid loop 25 which is attached to component 61 of a carriage 60. The carriage 60 can be manually set at a required position on the arm 14. The carriage 60 comprises a thumb screw operated adjuster 62 to tighten the lanyard to the lever arm by fixing the carriage 60 in a particular position. The lanyard can vary in length and the carriage 60 allows adjustment according to suit the length of lanyard used. The lanyard 10 extends over the surface 18, and to the attachment points 5a and 5b on the cover 4.
The arming environment also comprises a solenoid safety device 90, as best shown in Figure 1A. The device 90 allows a loop 30c of an extension 30b from the lanyard 30 to be held by a retractable pin 91. Operation of the solenoid causes the pin to retract into the solenoid housing. The arming mechanism will not operate until the lanyard extension 30b has been released by the solenoid. The solenoid 90 must receive an electrical pulse signal from the aircraft to activate allowing the aerial bomb to be armed on release from the aircraft. If the aerial bomb needs to be jettisoned, without arming (inert), the electrical pulse will not be sent and the bomb will fall away without the arming mechanism operating.
The transverse beam 16 is provided with a LEFA connector 40, which is arranged to connect with a plug which supplies the LEFA signal at the time of the deployment of the bomb. The LEFA signal is generated upon a command from the launch aircraft.
As can be seen in Figure 5, when in position on the aircraft, the fixation point (referenced F) for the eye 30a of the lanyard 30, is provided at a position which is out of registration/alignment from the position of the arming device 2 (referenced A). Put another way, the position of the aircraft's weapon retaining/releasing fixture shown generally at 70, where the fixation point is located, is offset from the position of the arming device 2. However, despite this positional 'mismatch' (as illustrated by the arrows in broken line), the arming assembly described here allows the required pulling force to be applied to the arming device 2, so as to deploy the same. Figure 5 shows two weapon retaining/releasing fixtures 70, and a weapon 100 which is releasably supported by one of the retaining/releasing fixtures. These are secured to a structural support member or beam 80. Each of the fixtures 70 releasably lock an aerial bomb in place until a signal is received to deploy (armed) or jettison (unarmed).
In use, when the bomb is mechanically released from the bomb release unit of the aircraft, a LEFA pulse generator (not illustrated) sends a standard LEFA pulse to the signal conditioning unit on the bomb through electrical wire 46. In order for the bomb to be armed, a signal from the alternator of the turbine also needs to be received. This is achieved by the reaction force (from the gravitational pull of the mass of the bomb) pulling a connection cable 45, connected to the fixture 70 and to the eye 30a, causing the lanyard 30 to pull the first end 13a of the lever arm along the guide shaft 20. In so doing, the arm portion 14 extending through the constrained aperture 19, the arm portion pivots by way of the pivot connection 15, and the second end, and at least some of the arm portion 14, progressively protrudes through the aperture 19, and outwardly of the casing of the bomb. This is turn causes the lanyard 10 to apply a pulling force to the cover 4, and therefore pull the cover off, out and away from its containing position. This upward force also causes the housing 2 to be pivoted out of its stowed position into a deployed condition. This causes the turbine 2 to be exposed to the surrounding air, which drives the turbine to cause an electrical current signal to be generated. The housing 2 in the deployed condition, and the lever arm extending outwardly is shown in Figure 5. For ease of representation, the portion of lanyard extending from the end 13b of the lever arm to the cover is omitted.
It will be appreciated that when the turbine 2 is in a stowed (i.e. undeployed) condition, there is a frangible junction between the cover 4 and an inner margin of the housing of the arming device 2.
It will be appreciated that other types of arming device can be used, an in particular other types which require a turbine to be pivoted into atmosphere.

Claims

An aerial bomb arming assembly, which comprises an air driven arming device (2), and the air driven arming device comprises a turbine which is arranged to rotate and generate an electrical current when exposed to atmosphere, and the turbine arranged for transition from a stowed condition to a deployed condition, and the assembly further comprising a lever arm (12) which comprises a first end (13a), a second end (13b) and an arm portion (14), and the first end is connected to the arm portion by way of a pivotable connection, and the first end is arranged for translational movement along a guide (20), and the second end of the arm portion arranged to provide a pulling force to the device when the first end translates on the guide, wherein the first end is arranged to be located within the internal space of the bomb, which internal space is defined within an outer casing.
An assembly as claimed in claim 1, in which the transition from the stowed condition to the deployed condition comprises exposing the turbine (2) to atmosphere.
An assembly as claimed in claim 1 or claim 2 in which the turbine (2) is arranged in a space which is provided with a cover or top (4), and the cover arranged to be removed or repositioned by way of the pulling force provided by the lever arm (12), so as to expose the arming turbine.
An assembly as claimed in any preceding claim in which the pivotable connection between the first end (13a) and the guide (20) allows said guide to pivot relative to the first end.
An assembly as claimed in any preceding claim in which the second end (13b) of the arm portion (14) is arranged to protrude externally of the outer casing or housing of the bomb.
An assembly as claimed in any preceding claim in which comprises a lanyard (30), one end of which is arranged to be attached to a fixation point fast with an aircraft, and another end of the lanyard is secured to the lever arm (12) so as, in use, to pull the first end (13a) along the guide (20).
An assembly as claimed in claim 6 in which the other end of the lanyard (30) is secured to the first end (13a).
An assembly as claimed in any preceding claim in which includes a lock device (70) which is arranged to prevent the lever arm (12) from being pulled to a deployed condition from a stowed condition, unless and until a signal is received by the lock device which is indicative of a command to deploy the aerial bomb in an armed condition.
An assembly as claimed in any preceding claim in which the lock device (70) comprises an electro-mechanical device, which may comprise a solenoid device.
An assembly as claimed in claim 8 or claim 9 in which the lock device (70) comprises a driven member which is driveable from a locked position to a released position, and the driven member arranged to retain and release a sub-assembly, such as a lanyard assembly (30), which is connected to the lever arm(12) and arranged to pull the lever arm along the guide (20) to a deployed condition.