GB1603227A - Activating devices for releasable load - Google Patents

Description

(54) IMPROVEMENTS TO ACTIVATING DEVICES FOR RELEASABLE LOAD (71) We, MATRA, a French Body Corporate of 4 rue de Presbourg, 75116 Paris, France, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates generally to devices for activating loads releasable from a carrying vehicle into a fluid of a type adapted to exert a drag force.

The problem of activating loads releasable from an air, sea or underwater vehicle is frequently met with. By way of example, bombs carried by an aircraft must be maintained in a safe condition until they are launched and "armed" after they have been released and separated from the aircraft.

Other examples are initiation of ejection of articles or products from a container released from an aircraft, starting up of the propulsion unit of a missile such as a torpedo, unfolding of the antennae of a sonobuoy (which should be delayed until after entry into the water, even in the case of aerial release).

There already exist numerous activating also called "arming" devices. For example, safety devices or timers have already been used for aircraft bombs which delay arming of the bombs for a predetermined time period after release of the bomb. Devices have also been used which comprise a cord or lanyard having one end adapted to be retained by an arming wire solenoid on the aircraft coiled on the bomb and which activates the latter after pay out. But the aerodynamic action of the aircraft tends to give to the cord a curved shape, so that complete pay out may have occurred whereas the bomb is still at a short distance from the aircraft. Damage to the aircraft may then be caused by fragments, pieces of wing, panels or even a load braking parachute breaking loose, opening out or jettisoned from the load.It has also been suggested to use airscrews driven by the air flow during the fall of the bomb. These solu tions are complex and cannot always be incorporated conveniently in the loads.

According to the invention, there is provided a load for transportation by an air or marine carrier vehicle from which it can be released to fall by gravity the load being provided with a device operable to cause or permit after a period of delay after the release of the load the operation of actuating means provided on the load said device comprising a drag member retained in a storage position in or on the load by releasable locking means the drag member when released from said storage position being subjected to a drag force which reduces the free fall speed of said load, means for connecting said locking means to the carrying vehicle for rendering inoperative said locking means upon release of the load from the carrying vehicle, flexible wire means stored in said load said flexible wire means being wound on a rotatable drum and having an end connected to said drag member and a movable member movable progressively and positively from a rest position upon rotation of the drum as a result of said flexible wire means being withdrawn from the load by the drag member said movable member comprising a plunger mounted so as to be axially slidable by rotation of the drum, the displacement of said movable member after it has been moved a predetermined distance from said position of rest causing or permitting the actuation of said actuating means.

The drag member may have very different shapes. It will typically be a parachute in the case of a load released in the atmosphere and having to be activated in the atmosphere, but other means can also be used. When the medium in which the release takes place is water, which causes a much greater drag, a plate or flap of small size can be used. In the case of a device released in the atmosphere and which must penetrate into water, the drag member may be so designed that the braking forces which are exerted thereon are insufficient to extract the traction member as long as the load falls through the atmosphere.

The invention will be better understood from the following description of a particular embodiment given by way of example. The description refers to the accompanying drawings in which: Fig. 1 is an overall side view of a load provided with a device in accordance with the invention and carried under the wing of an aircraft; Fig. 2 is an enlarged cross-sectional view of a fraction of the device of Fig. 1; Fig. 3 shows an enlarged longitudinal view of another fraction of the device and in particular of the drag member.

Referring to Fig. 1 there is schematically shown a load consisting of a bomb 10 mounted for transport on a pylon 11 under the wing 12 of an aircraft. The bomb is held by two coupling brackets or lugs 13 whiich will not be described for they may be conventional.

An extraction cord 14, which may be short in length and serves only to set the device in operation, is connected to an anchoring point or arming solenoid on the aircraft before take off. Between the end connected to point 15 and the end connected to the activating device the cord is stowed in an appropriate device, which is for example of the type described in British Patent No. 1,549,544.

Referring to Fig. 3, the activating device comprises a drag member formed by a small diameter parachute 16 which is folded on the tail section 17 of the load and which is held, as long as the load is carried, by a keeper 18 housed in a circular groove of the tail and encircling it. The keeper is arranged to be unlocked when the extraction cord 14 is stretched. For this purpose, the arrangement shown in Fig. 3 can be used, while other embodiments are possible. On Fig. 3, keeper 18 comprises a resiliently bent metal rod having end loops 19 and 20 through which is passed a locking pin 20 attached to cord 14.

The pin, once in place, is held by a shear pin 22, sufficiently weak to fracture under the pull of cord 14, and by a safety-pin 23 whic..

is manually removed after mounting the load under the aircraft and before take off.

The rigging lines 24 of the parachute 16 (which are only partly shown in Fig.

3) are connected to an end of a flexible tractive member, which controls load enabling means.

In the embodiment illustrated in Fig. 2 this member comprises a first resiliently stretchable section 25 for absorbing the shock when the parachute opens out and a main section formed by a wire or cable 26. The cable 26 penetrates through a throat into a casing 27 where there is rotatably mounted a drum 28 for storing the length of cable necessary for delaying the activation for a predetermined length of time. Drum 28 is rotatably mounted on a socket 29 secured to casing 27 and is non-rotatably connected to a plunger 30 provided with a threaded portion 31 which is extended by a finger 32. The threaded part 31 is coaxial with the drum, and threadedly received in an opening of socket 29. Before rotation of the drum, the threaded portion 31 projects completely into socket 29 and finger 32 retains a striker pin 33.As cable 26 is extracted by the parachute, drum 28 rotates plunger 30 which moves up until finger 32 releases striker pin 33 which then strikes a detonator 34 and activates the load. The threaded connection could obviously be replaced by another mechanism providing reduction of the amount of movement. Likewise, instead of a pyrotechnical device, a device of another nature could be controlled, such as a micro-switch, a valve etc.

The device comprises additional safety means preventing undue activation of the load as long as it is carried by the aircraft.

In the embodiment illustrated in Fig. 2, the safety means comprises a push-rod 35 consisting of several pieces, whose head is in abutting connection with a surface of the aircraft (schematized by a dash-dot line) when the load is airborne. A spring 37 is compressed between plunger 30 and push-rod 35 and tends to lift the rod. Upward movement of the rod before the load is located on the aircraft is prevented by a locking key (not shown) which is later manually removed. Pushrod 35 comprises a lower tubular part 36 which covers a tube 38 axially projecting from casing 27. As long as the plunger is retained in place, it covers holes 39 provided in tube 38 and holds in place balls 40 which lock plunger 30.

Since operation of the device appears from the preceding description, it will only be summarized.

Load 10 is first mounted on the aircraft.

The safety-pin 23 preventing parachute 16 from unfolding and the pin which holds pushrod 35 are manually removed. Cord 14 is connected to point 1S.

When the load is released and falls freely, cord 14 uncoils. When it is completely uncoiled, it snatches away pin 21 which shears pin 22. Keeper 18 is released and parachute 16 unfolds. The aerodynamic forces which are exerted thereon slow it down in relation to the load in free fall. The parachute exerts on its rigging lines a force which is transmitted by the resilient section 25 to cable 26.

At the moment when the load separates from the aircraft, spring 27 projects push-rod 35 upwards, thus freeing balls 40. Plunger 30 then becomes free to move axially. Cable 26 can therefore unwind while rotating drum 28 and plunger 30. Due to the threaded connection between casing and plunger 30, the latter moves axially and after a predetermined number of revolutions, releases firing-striker 33 which strikes detonator 34.

WHAT WE CLAIM IS: 1. A load for transportation by an air or

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   description refers to the accompanying drawings in which: Fig. 1 is an overall side view of a load provided with a device in accordance with the invention and carried under the wing of an aircraft; Fig. 2 is an enlarged cross-sectional view of a fraction of the device of Fig. 1; Fig. 3 shows an enlarged longitudinal view of another fraction of the device and in particular of the drag member.

   Referring to Fig. 1 there is schematically shown a load consisting of a bomb 10 mounted for transport on a pylon 11 under the wing 12 of an aircraft. The bomb is held by two coupling brackets or lugs 13 whiich will not be described for they may be conventional.

   An extraction cord 14, which may be short in length and serves only to set the device in operation, is connected to an anchoring point or arming solenoid on the aircraft before take off. Between the end connected to point 15 and the end connected to the activating device the cord is stowed in an appropriate device, which is for example of the type described in British Patent No. 1,549,544.

   Referring to Fig. 3, the activating device comprises a drag member formed by a small diameter parachute 16 which is folded on the tail section 17 of the load and which is held, as long as the load is carried, by a keeper 18 housed in a circular groove of the tail and encircling it. The keeper is arranged to be unlocked when the extraction cord 14 is stretched. For this purpose, the arrangement shown in Fig. 3 can be used, while other embodiments are possible. On Fig. 3, keeper 18 comprises a resiliently bent metal rod having end loops 19 and 20 through which is passed a locking pin 20 attached to cord 14.

   The pin, once in place, is held by a shear pin 22, sufficiently weak to fracture under the pull of cord 14, and by a safety-pin 23 whic..

   is manually removed after mounting the load under the aircraft and before take off.

   The rigging lines 24 of the parachute 16 (which are only partly shown in Fig.

   3) are connected to an end of a flexible tractive member, which controls load enabling means.

   In the embodiment illustrated in Fig. 2 this member comprises a first resiliently stretchable section 25 for absorbing the shock when the parachute opens out and a main section formed by a wire or cable 26. The cable 26 penetrates through a throat into a casing 27 where there is rotatably mounted a drum 28 for storing the length of cable necessary for delaying the activation for a predetermined length of time. Drum 28 is rotatably mounted on a socket 29 secured to casing 27 and is non-rotatably connected to a plunger 30 provided with a threaded portion 31 which is extended by a finger 32. The threaded part 31 is coaxial with the drum, and threadedly received in an opening of socket 29. Before rotation of the drum, the threaded portion 31 projects completely into socket 29 and finger 32 retains a striker pin 33.As cable 26 is extracted by the parachute, drum 28 rotates plunger 30 which moves up until finger 32 releases striker pin 33 which then strikes a detonator 34 and activates the load. The threaded connection could obviously be replaced by another mechanism providing reduction of the amount of movement. Likewise, instead of a pyrotechnical device, a device of another nature could be controlled, such as a micro-switch, a valve etc.

   The device comprises additional safety means preventing undue activation of the load as long as it is carried by the aircraft.

   In the embodiment illustrated in Fig. 2, the safety means comprises a push-rod 35 consisting of several pieces, whose head is in abutting connection with a surface of the aircraft (schematized by a dash-dot line) when the load is airborne. A spring 37 is compressed between plunger 30 and push-rod 35 and tends to lift the rod. Upward movement of the rod before the load is located on the aircraft is prevented by a locking key (not shown) which is later manually removed. Pushrod 35 comprises a lower tubular part 36 which covers a tube 38 axially projecting from casing 27. As long as the plunger is retained in place, it covers holes 39 provided in tube 38 and holds in place balls 40 which lock plunger 30.

   Since operation of the device appears from the preceding description, it will only be summarized.

   Load 10 is first mounted on the aircraft.

   The safety-pin 23 preventing parachute 16 from unfolding and the pin which holds pushrod 35 are manually removed. Cord 14 is connected to point 1S.

   When the load is released and falls freely, cord 14 uncoils. When it is completely uncoiled, it snatches away pin 21 which shears pin 22. Keeper 18 is released and parachute 16 unfolds. The aerodynamic forces which are exerted thereon slow it down in relation to the load in free fall. The parachute exerts on its rigging lines a force which is transmitted by the resilient section 25 to cable 26.

   At the moment when the load separates from the aircraft, spring 27 projects push-rod 35 upwards, thus freeing balls 40. Plunger 30 then becomes free to move axially. Cable 26 can therefore unwind while rotating drum 28 and plunger 30. Due to the threaded connection between casing and plunger 30, the latter moves axially and after a predetermined number of revolutions, releases firing-striker 33 which strikes detonator 34.

   WHAT WE CLAIM IS: 1. A load for transportation by an air or

   marine carrier vehicle from which it can be released to fall by gravity the load being provided with a device operable to cause or permit after a period of delay after the release of the load the operation of actuating means provided on the load said device comprising a drag member retained in a storage position in or on the load by releasable locking means the drag member when released from said storage position being subjected to a drag force which reduces the free fall speed of said load, means for connecting said locking means to the carrying vehicle for rendering inoperative said locking means upon release of the load from the carrying vehicle, flexible wire means stored in said load said flexible wire means being wound on a rotatable drum and having an end connected to said drag member and a movable member movable progressively and positively from a rest position upon rotation of the drum as a result of said flexible wire means being withdrawn from the load by the drag member said movable member comprising a plunger mounted so as to be axially slidable by rotation of the drum, the displacement of said movable member after it has been moved a predetermined distance from said position of rest causing or permitting the actuation of said actuating means.
2. 2. A combined load and device as claimed in Claim 1, wherein the means for rendering inoperative the locking means comprise a locking pin releasable from a locking position by a cord connected to said pin and connectable to the carrying vehicle when the load is installed on the vehicle, the pin being released by a pull on the cord upon separation of the load from the vehicle.
3. 3. A combined load and device as claimed in any one of the preceding claims, wherein said wire means has a resilient section.
4. 4. A combined load and device according to any one of the preceding claims, wherein the drag member is a parachute.
5. 5. A combined load and device according to Claim 4, wherein said parachute is stored in or on a rear portion of said load.
6. 6. A combined load and device as claimed in Claim 1 constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.