GB1588917A

GB1588917A - Parachute load-laying device

Info

Publication number: GB1588917A
Application number: GB3984575A
Authority: GB
Original assignee: Forces Armees Francaises
Current assignee: Forces Armees Francaises
Priority date: 1974-11-28
Filing date: 1975-09-29
Publication date: 1981-04-29
Also published as: DE2553040A1; CA1096031A; FR2438587A1; FR2438587B1

Description

(54) PARACHUTE LOAD-LAYING DEVICE (71) We, ETAT FRANCAIS, represented by the MINISTERIAL DELGATE FOR ARMAMENTS, of 14 rue Saint Dominique, 75997-Paris Armees, 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 to a device for laying floatable bodies in aqueous environments from elevated altitudes.

Underwater listening buoys are frequently laid in the sea from aeroplanes or helicopters.

Such buoys initially form compact units comprising radio equipment disposed in watertight casings, and electro-acoustic equipment.

On contact with the water the compactness of the buoys is lost as the electro-acoustic equipment becomes spaced apart from the radio equipment as it sinks in the water to a predetermined depth while remaining connected to the radio equipment by a suspension link which has both electrical and mechanical junctions. The suspension is usually a coiled cable. The radio equipment is mechanically and electrically connected to an antenna for the transmission of radio waves towards an aircraft in which the radio waves are processed.

A characteristic requirement in the laying of a device of the aforesaid type is the requirement that it should not be damaged when it comes into contact with the water.

To retard the descent of the device, it is usual to employ either a rotochute of the autogyro type, or a parachute, preferably a parachute of cruciform type.

Laying devices comprising a cruciform parachute sometimes comprise an inflatable float associated with the parachute. There is attached to the float a wire which becomes tensioned when the float is inflated and operates as an antenna. Such a form of laying device is very simple, and is of small overall dimensions when folded and ensures good insulation against sea water. Moreover, the antenna is inexpensive. However, this form of laying device offers considerable wind resistance so that the buoy, when laid, is caused to drift. Hence errors in the location of a source of a signal therefrom occur. The wind resistance also causes the antenna to become inclined. This has an unsatisfactory effect on the transmission ability of the radio equipment.The drifting of the radio equipment resulting from the wind resistance of the antenna furthermore leads to production of induced noise on the cable carrying the electroacoustic equipment, thereby reducing the sensitivity of the latter.

Although an antenna as aforesaid is inexpensive, a laying device as aforesaid is otherwise expensive to manufacture because of the considerable quantity of waterproof fabric which must be used in its manufacture. Moreover, specialised labour is required for the device to be assembled.

The inflatable floats in the devices of the aforesaid type generally require specific inflating devices such as compressed-air bottles.

The floats generally consist of a sphere on which there is mounted a cone. Hence they are difficult to produce. Alternatively they may be of tetrahedral form in which case they have insufficient reserve of buoyancy if the foot of the antenna should be positioned below water level.

According to the present invention, there is provided a parachute device for laying a load from an elevated position into a freshwater or marine environment, which comprises a parachute, an inflatable float which when inflated is pillow shaped and capable of maintaining a load of predetermined mass at a predetermined depth and affixed to a central position of the parachute, an elongate sleeve member attached to one side of the float for communicating the float interior with the atmosphere during descent of the parachute and having the end thereof remote from the float attached to one end of a connecting member the other end of which is adapted for or capable of attachment to the load.A parachute device embodying this invention will usually further comprise a plurality of suspension wires connecting the paratchute to a carrying member having associated means for connection thereof to a said load.

With the parachute device embodying this invention it is preferred that the parachute be cruciform and the float, forming the central part of the parachute, is formed from two squares of fabric which are adhesively bonded together at their edges, one of the fabric squares having an opening therein at which said sleeve member is attached to the float, the parachute further comprising four rectangular arms, whereby it is rendered cruciform, fixedly connected to said one fabric square along a shorter edge of each.In practice, the four rectangular arms of the parachute will usually be connected to said fabric square by sewing or adhesive bonding, in which case waterproof strips are prefer ably adhesively bonded both to the rectangular arms of the parachute and to said one fabric square to protect against ingress of water into the float, by protecting the sewn or adhesive bonds between the rectangular arms of the parachute and said one fabric square.

The elongate sleeve member is preferably of frusto-conical form, having its smaller diameter end at the position at which it is connected to the float. The elongate sleeve member may comprise a plug located therein at a position adjacent the larger diameter end thereof, having at least one passage therethrough and provided with a valve comprising a flexible fabric element for achieving retention of air in the float in use. The plug can be a hollow tubular member in which is positioned a multi-armed member whose arms extend from an axial member having a channel therethrough in which is fixed said one end of the connecting member, the flexible fabric element being attached to one end of the hollow tubular member and being shaped to co-operate with a seating in the said one end of the hollow tubular member.

The device of this invention is particularly applicable to the laying of submersible listening devices, in which case the load comprises an electro-acoustic device. A whip antenna can then be carried on the side of the float opposite to that to which the elongate sleeve member is attached. The foot of the whip antenna is preferably secured to a rigid plate which is adhesively secured to the side of the float opposite to that to which the elongate sleeve member is attached, which plate forms one side of a box which contains a radio transmission device. A resilient member may be provided to connect the opposite sides of the float, whereby, in use, the antenna is retained in a substantialiy vertical position.

When a load carried by the device is intended to be submerged after impact with water a form of parachute device embodying this invention is preferably used in which the load is further attached to the parachute by means of a carrying sling, one end of which is attached to the carrying member and the other end of which is connected to the load by means of a coupling device com prising a rocking fastener to which said con necting member froni the sleeve member is also attached, the load being further con nected to the coupling device by means of a resilient linking member which retains con nection of the load to the coupling device when, in use, the rocking fastener has other wise disconnected the coupling member from the load.The coupling device itself may comprise two plate members each having a straight edge, a pair of attachment positions spaced apart along said edge and a recess therein positioned closer to one said attach ment position than the other said attachment position, the recesses being engaged by a hook connected to the load, the carrying sling being attached to the coupling device at said one attachment positions and the connecting mem ber being attached to the coupling device at the said other attachment positions.

For a better understanding of the inven- tion and to show how the same may be carried into effect reference will now be made by way of example only, to the accompanying drawings, in which: Figure 1 is an elevational view, partly in section of a laying device embodying this invention, Figure 2 is a more sectional view of part of the device of Figure 1, and Figure 3 is a plan view of the device of Figures 1 and 2 when undergoing descent.

Referring to Figure 1, there is shown a laying device comprising a cruciform para chute 1 (see also Figure 3) which supports, in its central region, a pillow-shaped inflat able float 2 consisting of two squares 3 of waterproof fabric stuck edge-to-edge. Secured to the centre of the upper square 3 of the fabric is a whip antenna 4. The whip antenna is attached to a rigid disc 5 which is adhesively secured to the square of fabric and is intended to support the antenna, the antenna passing through a central orifice in the plate s in which it is fixed, for example bv screwing. Three braided metal strips 5a torming a radio ground plane are also fixed to the disc 5. The disc 5 also constitutes the lid of a box B containing radio transmission equipment.

The lower square 3 is formed in its central part with an orifice at which it is connected to a sleeve 6 of frustoconical form. The centre of the end of the sleeve 6 connected to the lower square 3 is joined to the box B of the transmission equipment by means of an elastic element 7. The sleeve 6 is made of waterproof fabric. Its mean diameter is less than about 10 centimetres, while its length is from 20 centimetres to 1 metre, depending upon the value of the superatmospheric pressure which must be set up in the float 2 in order to allow it to maintain its form.

As can be seen from Figure 2, the sleeve 6 comprises, at its end opposite to the float 2, a valve 8 consisting of a hollow cylindrical plug of plastics material, which is provided with a multi-armed member 9 and a seat 10 for a valve member 11 consisting of a flexible piece of fabric fixed to the centre of the member 9 by means of a rivet 12 which engages in an axial passage 13 in the multi-armed member 9. If desired, however, the valve member 11 can be dispensed with.

Secured in the passage 13 is the upper end of the connecting member 14 for tensioning the sleeve 6.

Before reverting to Figure 1, reference is made to Figure 3 in which the cruciform parachute 1 can be seen to be formed of four rectangles 15 of fabric or plastics sheet, which are adhesively secured each at one of its short edges to the lower square 3 of the float 2, the seams or bonds produced being shown at 16.

The seams or adhesive bonds 16 are protected by waterproof strips 17 (see Figure 2) which ensure the fluid-tightness of the float and reinforce the parachute. The strips 17 are themselves adhesively secured to the rectangle 15 and the lower square 3 over seams or adhesive bonds 16.

Suspension lines 18 extending through the parachute and connecting together two opposite rectangles 15 of the latter are secured to those sides of the rectangles 15 which are adjacent the stitched seams or adhesive bonds 16. Reverting to Figure 1, it can be seen that the suspension lines 18 are connected to a central member 19, to the centre of which there is attached the upper end of a carrying sling 20, the lower end of which supports a load 21 which is to be spatially separated, but not disconnected from the remainder of the device as the latter floats on water. Although not shown in the drawings, the rectangles 15 may be discontinuous, the margins of the discontinuities being connected to the margins of a funnel which serves to stabilise the parachute.

The load 21 contains electro-acoustic equipment connected to the antenna 4 by a conductor (not shown). The load 21 is secured to the carrying sling 20 by means of a coupling device 22 comprising a rocking fastener. The latter consists of two plates 23 having a straight edge 24 and a lateral recess 25 in which there is engaged a hook 26 which is fast with a rod 27 attached to the load 21.

The carrying sling 20 is secured to the ends of the rectilinear edges 24 of the plates 23 which are closer to the recess 25.

At the ends of the edges 24 opposite to those at which they are secured to the sling 20, the plates 23 are secured to the connecting member 14 which extends through the member 19 for the connection of the suspension lines 18 to the carrying sling 20, by way of an orifice 28 in the latter. The coupling device 22 is connected to the load 21 by means of a resilient link 29 which may be an extensible spring having a length of about 2.50 m.

The illustrated device functions in the following manner.

Prior to dropping from, for example, an aircraft, the sling 20 is folded into two equal halves, which are held together by a snappable filament (not shown). It is also possible, although not shown, for a shock absorber to be inserted between the sling 20 and the coupling device 22.

When the parachute opens out, the carrying sling 20 is more tightly tensioned than the connecting member 14. The filament by which the two halves of the sling are held together snaps, so that the sling constitutes the sole means for the suspension of the load 21 during the descent of the parachute. The connecting member 14 maintains the sleeve 6 in a position such that the increase in the air pressure therein, due to the descent, causes air to be funnelled into the sleeve, ro cause inflation of the float 2.

When the load 21 comes into contact with the water, the tension in the carrying sling 20 is relaxed and the connecting member 14 causes the coupling device 22 to rock and to release the hook 26. The load is then connected to the remainder of the device only by the resilient link 29 and by the electric connecting cable. The superatmospheric pres sure in the float 2 is considerably increased by~the admission of water into the lower part of the sleeve. The valve member is then applied by the water against its seat 10, pre vents any escape of water and this confines the air within the float.

The elastic element 7 exerts on the opposite walls of the float 2 a compensating force for the pressure of the air entering the float through the sleeve 6, and this, together with the valve 8, serves to ensure that the antenna remains in an upright position.

The weight of the load 21 is such that when immersed it is freed from the sling 20 and acts as a floating anchor for the electro-acoustic unit.

WHAT WE CLAIM IS: 1. A parachute device for laying a load from an elevated position into a fresh-water or marine environment, which comprises a parachute, an inflatable float which, when inflated, is pillow shaped and capable of maintaining a load of predetermined mass at a predetermined depth and, affixed to a central position of the parachute, an elongate sleeve member attached to one side of the float for communicating the float interior with the atmosphere during descent of the parachute and having the end thereof remote from the float attached to one end of a connecting

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Claims

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to allow it to maintain its form.

As can be seen from Figure 2, the sleeve 6 comprises, at its end opposite to the float 2, a valve 8 consisting of a hollow cylindrical plug of plastics material, which is provided with a multi-armed member 9 and a seat 10 for a valve member 11 consisting of a flexible piece of fabric fixed to the centre of the member 9 by means of a rivet 12 which engages in an axial passage 13 in the multi-armed member 9. If desired, however, the valve member 11 can be dispensed with.

Secured in the passage 13 is the upper end of the connecting member 14 for tensioning the sleeve 6.

Before reverting to Figure 1, reference is made to Figure 3 in which the cruciform parachute 1 can be seen to be formed of four rectangles 15 of fabric or plastics sheet, which are adhesively secured each at one of its short edges to the lower square 3 of the float 2, the seams or bonds produced being shown at 16.

The seams or adhesive bonds 16 are protected by waterproof strips 17 (see Figure 2) which ensure the fluid-tightness of the float and reinforce the parachute. The strips 17 are themselves adhesively secured to the rectangle 15 and the lower square 3 over seams or adhesive bonds 16.

Suspension lines 18 extending through the parachute and connecting together two opposite rectangles 15 of the latter are secured to those sides of the rectangles 15 which are adjacent the stitched seams or adhesive bonds 16. Reverting to Figure 1, it can be seen that the suspension lines 18 are connected to a central member 19, to the centre of which there is attached the upper end of a carrying sling 20, the lower end of which supports a load 21 which is to be spatially separated, but not disconnected from the remainder of the device as the latter floats on water. Although not shown in the drawings, the rectangles 15 may be discontinuous, the margins of the discontinuities being connected to the margins of a funnel which serves to stabilise the parachute.

The load 21 contains electro-acoustic equipment connected to the antenna 4 by a conductor (not shown). The load 21 is secured to the carrying sling 20 by means of a coupling device 22 comprising a rocking fastener. The latter consists of two plates 23 having a straight edge 24 and a lateral recess 25 in which there is engaged a hook 26 which is fast with a rod 27 attached to the load 21.

The carrying sling 20 is secured to the ends of the rectilinear edges 24 of the plates 23 which are closer to the recess 25.

At the ends of the edges 24 opposite to those at which they are secured to the sling 20, the plates 23 are secured to the connecting member 14 which extends through the member 19 for the connection of the suspension lines 18 to the carrying sling 20, by way of an orifice 28 in the latter. The coupling device 22 is connected to the load 21 by means of a resilient link 29 which may be an extensible spring having a length of about 2.50 m.

The illustrated device functions in the following manner.

Prior to dropping from, for example, an aircraft, the sling 20 is folded into two equal halves, which are held together by a snappable filament (not shown). It is also possible, although not shown, for a shock absorber to be inserted between the sling 20 and the coupling device 22.

When the parachute opens out, the carrying sling 20 is more tightly tensioned than the connecting member 14. The filament by which the two halves of the sling are held together snaps, so that the sling constitutes the sole means for the suspension of the load 21 during the descent of the parachute. The connecting member 14 maintains the sleeve

6 in a position such that the increase in the air pressure therein, due to the descent, causes air to be funnelled into the sleeve, ro cause inflation of the float 2.

When the load 21 comes into contact with the water, the tension in the carrying sling 20 is relaxed and the connecting member 14 causes the coupling device 22 to rock and to release the hook 26. The load is then connected to the remainder of the device only by the resilient link 29 and by the electric connecting cable. The superatmospheric pres sure in the float 2 is considerably increased by~the admission of water into the lower part of the sleeve. The valve member is then applied by the water against its seat 10, pre vents any escape of water and this confines the air within the float.

The elastic element 7 exerts on the opposite walls of the float 2 a compensating force for the pressure of the air entering the float through the sleeve 6, and this, together with the valve 8, serves to ensure that the antenna remains in an upright position.

The weight of the load 21 is such that when immersed it is freed from the sling

20 and acts as a floating anchor for the electro-acoustic unit.

WHAT WE CLAIM IS: 1. A parachute device for laying a load from an elevated position into a fresh-water or marine environment, which comprises a parachute, an inflatable float which, when inflated, is pillow shaped and capable of maintaining a load of predetermined mass at a predetermined depth and, affixed to a central position of the parachute, an elongate sleeve member attached to one side of the float for communicating the float interior with the atmosphere during descent of the parachute and having the end thereof remote from the float attached to one end of a connecting

member the other end of which is adapted for or capable of attachment to the load.
2. A parachute device as claimed in Claim 1. which further comprises a plurality of suspension lines connecting the parachute to a carrying member having associated means for connection thereof to a said load.
3. A device as claimed in Claim 1 or 2, in which the parachute is cruciform and the float, forming the central part of the parachute, is formed from two squares of fabric which are adhesively bonded together at their edges, one of the fabric squares having an opening therein at which said sleeve member is attached to the float, the parachute further comprising four rectangular arms, whereby it is rendered cruciform, fixedly connected to said one fabric square along a shorter edge of each.
4. A device as claimed in Claim 3, in which the four rectangular arms of the parachute are connected to said one fabric square by sewing or adhesive bonding.
5. A device as claimed in Claim 4, in which waterproof strips are adhesively bonded both to the rectangular arms of the parachute and to said one fabric square to protect against ingress of water into the float, by protecting the sewn or adhesive bonds between the rectangular arms of the parachute and said one fabric square.
6. A device as claimed in any one of Claims 1 to 5, in which the elongate sleeve member is of frusto-conical form, having its smaller diameter end at the position at which it is connected to the float.
7. A device as claimed in Claim 6, in which the elongate sleeve member comprises a plug located therein at a position adjacent the larger diameter end thereof, having at least one passage therethrough and provided with a valve comprising a flexible fabric element for achieving retention of air in the float in use.
8. A device as claimed in Claim 7, in which the plug is a hollow tubular member in which is positioned a multi-armed member whose arms extend from an axial member having a channel therethrough in which is fixed said one end of the connecting member, the flexible fabric element being attached to one end of the hollow tubular member and being shaped to co-operate with a seating in the said one end of the hollow tubular member.
9. A device as claimed in any one of the preceding claims, in which a whip antenna is carried on the side of the float opposite to that to which the elongate sleeve member is attached.
10. A device as claimed in Claim 9, in which the foot of the whip antenna is secured to a rigid plate which is adhesively secured to the side of the float opposite to that to which the elongate sleeve member is attached, which plate forms one side of a box which contains a radio transmission device.
11. A device as claimed in Claim 9 or 10, which further comprises a resilient member connecting the opposite sides of the float.

whereby, in use, the antenna Is retained in a substantially vertical position.
12. A device as claimed in any one of Claims 1 to 8, which further comprises a said load attached to said other end of the connecting member.
13. A device as claimed in Claim 9, 10 or 11, for laying an underwater listening buoy, which further comprises a said load attached to said other end of the connecting member and containing an electro-acoustic device connected to radio transmission equipment associated with the float.
14. A device as claimed in Claim 12 or 13, when appended to Claim 2, in which the load is further attached to the parachute by means of a carrying sling, one end of which is attached to the carrying member and the other end of which is connected to the load by means of a coupling device comprising a rocking fastener to which said connecting member from the sleeve member is also attached, the load being further connected to the coupling device by means of a resilient linking member which retains connection of the load to the coupling device when, in use, the rocking fastener has otherwise disconnected the coupling member from the load.
15. A device as claimed in Claim 14, in which the coupling device comprises two plate members each having a straight edge, a pair of attachment positions spaced apart along said edge and a recess therein positioned closer to one said attachment position than the other said attachment position, the recesses being engaged by a hook connected to the load, the carrying sling being attached to the coupling device at said one attachment positions and the connecting member being attached to the coupling device at the said other attachment positions.
16. A parachute device as claimed in Claim 1, substantially as hereinbefore described with reference to, and as shown in, Figures 1 to 3 of the accompanying drawings.
17. A device for laying an underwater listening buoy, substantially as hereinbefore described with reference to and as shown in, Figures 1 to 3 of the accompanying drawings.