GB2218950A

GB2218950A - An air descent control and flotation device

Info

Publication number: GB2218950A
Application number: GB8907452A
Authority: GB
Inventors: Murray O Hill
Original assignee: Minister of National Defence of Canada; UK Secretary of State for Defence
Current assignee: Minister of National Defence of Canada; UK Secretary of State for Defence
Priority date: 1988-05-26
Filing date: 1989-04-03
Publication date: 1989-11-29
Anticipated expiration: 2009-04-03
Also published as: GB8907452D0; GB2218950B

Abstract

An air descent control and flotation device comprising a collapsible, inflatable bag having a bottom end adapted for connection to an object to be dropped into a body of water from a height, the bag being configured to produce substantial aerodynamic drag when inflated and passing through air bottom end first, so as to slow descent of the object when dropped, the bag having an inflated volume sufficient to float the object at the surface of the body of water. Various shapes are disclosed. The bag may incorporate a directional discontinuity ring radiator antenna 18 including an upper open wire loop 20 with an impedance match section 22 connected at 24 to core 26 of a coaxial line 28, and connected at 30 to a braided wire 32 forming a second loop, which is connected at 34 to the shield of the coaxial line 28. <IMAGE>

Description

AN AIR DESCENT CONTROL AND FLOTATION DEVICE The present invention relates to a combined air descent control and flotation device for use with an object to be dropped into a body of water from a height.

Conventionally, bodies that are dropped into water from a height, for example from an aircraft, carry separate air descent control and flotation devices. The air descent control device may be, for example, a parachute or a rotochute. The flotation device is usually inflated upon water entry and may be in the form of a bag, ring or the like. In some circumstances, as when dealing with large numberS of small objects to be dropped into a body of water, it is desirable to limit the size and complexity of the complete package to be air dropped. The present invention proposes a device that combines the function of the air descent control apparatus and the flotation device.

According to the present invention there is provided an air descent control and flotation device comprising a collapsible, inflatable bag having a bottom end adapted for connection to an object to be dropped into a body of water from a height, the bag being configured to produce substantial aerodynamic drag when inflated and passing through air bottom end first, so as to slow descent of the object when dropped, the bag having an inflated volume sufficient to float the object at the surface of the body of water.

Where the object to be dropped into water contains a telecommunications apparatus, an antenna may be integrated with the wall of the inflatible bag so that the antenna is deployed by inflation of the bag.

In the accompanying drawings, which illustrate exemplary embodiments of the present invention: Figure 1 is a perspective view of one embodiment of the descent control and flotation device; Figure 2 is an elevational view, partially broken away of the device of Figure 1; Figure 3 is an elevational view of an alternative form of the device; and Figure 4 is an elevational view of a third embodiment of the device.

Referring to the drawinys, and particularly to Figures 1 and 2, there is illustrated a combined descent control and flotation device 10. This device is in the form of an inflatable bag with a right cylindrical side wall 12 and a frustoconical bottom end 14 with a central neck 16. The frustoconical send 14 acts as a braking panel when the neck of the inflated bag is secured to an object that is falling through the air.

The device illustrated in Figures 1 and 2 also incorporates a directional discontinuity ring radiator antenna 18.

This device includes an upper open wire loop 20 that is spaced slightly below the top of the side wall. One end of this loop is an impedance match section 22 that is connected at a position 24 spaced from its end to the core 26 of a co-axial feed line 28.

The end of the impedance match section 22 is connected at 30 to a braided wire 32 that forms another loop spaced below and parallel to the loop of wire 20. The shield of the co-axial feed line 28 is connected to the braided wire 32 at 34.

The directional discontinuity ring radiator antenna thus constructed is attached internally to the float material. The antenna requires a significantly smaller float to house it than the conventionally used quarter wave ground plane antenna, while providing a vertically polarized radiation pattern.

Turning to Figure 3, there is illustrated an air descent control and flotation device 40 that is generally similar to the device 10 of Figures 1 and 2. In this case however, the side wall 42 of the device is frustoconical, tapering from bottom to top.

The top panel 44 of the device is flat.

Figure 4 illustrates a third embodiment of the device where the side wall 52 is conical.

The embodiments of Figures 3 and 4 may include helically wound antennas that are deployed with the inflation of the bag.

While certain embodiments of the present invention have been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention. In particular, it is to be understood that different shapes of inflatable bag and different antenna configurations can be employed.

Claims

1. An air descent control and flotation device comprising a collapsible, inflatable bag having a bottom end adapted for connection to an object to be dropped into a body of water from a height, the bag being configured to produce substantial aerodynamic drag when inflated and passing through air bottom end first, so as to slow descent of the object when dropped, the bag having an inflated volume sufficient to float the object at the surface of the body water.

2. A device according to claim 1 and including a neck at the centre of the bottom end of the bag.

3. A device according to claim I or claim 2 wherein the bottom end of the bag is of frustoconical configuration.

4. A device according to any one of the preceding claims wherein the inflated bag has a right circular cylindrical side.

5. A device according to any one of the preceding claims wherein the inflated bag has a conical top surface.

6. A device according to any one of claims I to 3 wherein the inflated bag has a flat top surface and a frusto conical side.

7. A device according to any one of the preceding claims and including ahEicaly wound antenna inside the bag.

8. A device according to any one of claims 1 to 6 and including a directional discontinuity ring radiator antenna attached to the wall of the bag.

9. An air descent control and flotation device substantially as herein described with reference to Figures 1 and 2, Figure 3 or Figure 4 of the accompanying drawings.