GB2378819A

GB2378819A - Personal locator with collapsible reflector

Info

Publication number: GB2378819A
Application number: GB0107030A
Authority: GB
Inventors: Hugh Christopher Greenwell
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-21
Filing date: 2001-03-21
Publication date: 2003-02-19
Also published as: GB0107030D0

Abstract

A personal location device comprises a collapsible radar reflector attached to or within a balloon to be inflated when in use. The reflector when deployed comprises three mutually orthogonal intersecting planes, the structural integrity of which are retained by the tension of a line (6) attached to the balloon or by the inflated balloon itself. The reflector may be collapsed by dividing one of the intersecting planes in half (13, 14) and folding the structure about a common intersecting axis into a small package suitable for keeping in a pocket. The reflector device may be kept on a life jacket for use at sea and may be configured to deploy automatically.

Description

PERSONAL LOCATOR The described invention relates to the field of personal location equipment for use in marine or land-based environments where precise location of lost or injured personnel is difficult due to adverse weather conditions, difficult terrain, imprecise knowledge of position or poor light. A further embodiment of the invention may be as a location marker, for example, for equipment. An alternative use may be as a decoy for radar guided missiles.

Such radar reflecting devices are well known, but in general suffer from the disadvantage that, when collapsed or deflated they are too large to fit into a small pocket on a garment, and thus necessitate a separate container to be carried. Those devices described as fully collapsible often do not deploy automatically. Furthermore existing designs are difficult to fabricate, often needing multiple fixture points for the reflector to the interior of a balloon structure.

An object of this invention is to provide a personal location device for marine or wilderness use, which is radar reflective, inflatable and may be kept when collapsed within a small pocket on, for example, a life jacket or other item of outdoor clothing.

Accordingly, this invention provides a corner type radar retroreflector that is collapsible to a small volume that may be contained within, or suspended below, an inflatable balloon. The pressure of gas within the balloon, and the construction of the reflector, maintain the structural integrity of the erected corner radar reflector.

Preferably the corner radar retroreflector is made of a flexible radar reflective material such as foil or metal-coated PET film. The balloon will be of a radar permeable material, preferably of a highly visible colour, and be connected to a supply of,

preferably, lighter than air gas. The device may be activated either automatically by, for example, a water sensitive valve, or, manually.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which: FIGURE 1 shows a schematic view of the entire invention when in use as a personal location device in the marine environment. Both preferred embodiments are detailed, (A) shows the reflector suspended below the balloon, whilst (B) illustrates how the reflector may be incorporated within the balloon.

FIGURE 2 shows a perspective view of the corner radar retroreflector 7, showing its axis of common intersection 12.

FIGURE 3 shows, by a perspective view, the construction of the corner radar reflector.

FIGURE 4 shows both a plan and perspective view of the fully erect corner radar reflector.

FIGURES 5-9 are plan and perspective views of the corner radar reflector partially erected, illustrating the mechanism by which the invention collapses.

FIGURE 10 shows how the fully collapsed structure may be folded to a small volume

FIGURE 11 is a perspective view that shows the mechanism by which the reflector opens when suspended beneath a balloon containing a lighter than air gas where the tube that the gas passes through is used as a tether for the balloon.

FIGURE 12 is a perspective view that shows the mechanism by which the reflector opens when suspended beneath a balloon containing a lighter than air gas where the reflector is independently fastened to the balloon and the garment.

As shown in Figure 1, the personal locator device 11, containing the corner radar reflector 7 may be utilised within a marine environment 2 in conjunction with other rescue aid devices, such as the flashing LED 8, not illustrated. It is envisaged that the radar reflector 7 will be deployed suspended beneath a balloon 9 filled with a lighter than air gas as shown in Figure 1 a. The pressure exerted by the balloon 9 along its flexible gas line 6 will open and erect the corner radar reflector 7 as detailed in Figure 11 and 12. A further embodiment of the invention is also illustrated in Figure 1 b whereby the radar reflector is retained within a radar permeable balloon 10 containing a lighter than air gas.

As shown in Figure 2 when erected the device forms a comer type radar reflector 7, which has an axis of common intersection 12, where the pressure exerted by the balloon maintains the structural integrity of the corner reflector array.

Figure 3 illustrates the preferred basic components of the reflector design prior to assembly. The reflector is composed of four sheets of flexible radar reflective material, denoted as parts 13,14, 15 and 16. Though square sheets are illustrated other shapes could be utilised. Parts 13 and 14 are joined over about half of their surface area, as indicated by the shaded area. Part 15 may then be joined to the composite of parts 13 and 14 by means of the slots E and F and fixing along the seam. Part 16 is cut in two along a diagonal, giving parts 16a and 16b. These are fixed to both part 15 by means of the slot C aligning with D, in the case of 16a, and slot B

aligning with slot A for 16b. Part 16a is then joined along its longest edge to the face of part 14 by taping, gluing, etc. The same is done to join part 16b to part 13. The result will be the collapsible radar reflector as illustrated in Figures 4 to 9.

Figures 4 to 9 show sequentially the stages of collapse for the radar reflector. At partial erection the device has limited structural integrity as a corner reflector, the mechanism by which the horizontal component may be folded for compactness is clearly visible. The area of 13 and 14 not bonded in Figure 3 is able to move apart about the axis of intersection 12 in Figure 2. Figure 4 shows the fully erect structure where surfaces 13 and 14 are held together, by a mechanism such as shown in Figure 11 and 12 or within a radar permeable envelope. Figures 5 and 6 illustrate the radar reflector in the initial stages of collapse with the shaded areas of 13 and 14 moving apart. The vertical component 15 starts to rotate about axis 12 and the horizontal components 16 start to fold in the manner shown. Figure 7 shows the radar reflector at half erect stage. Figures 8 and 9 show the initial stages of erection from the reverse side to Figures 4 to 7, illustrating the mechanism by which the components 16a and 16b fold when collapsed. Figure 9 shows the structure at near full collapse. When not in use the reflector is folded as in Figure 10 and retained in a small pocket with the balloon, gas cylinder and inflation device (not shown). Where the reflector is contained within a radar permeable envelope, as illustrated in Figure 1 b, the faces of the octahedra are covered with a radar permeable material (not shown). The envelope is preferably continuous and is ideally fixed only at the edges of the non-bonded area of 13 and 14, facilitating easier construction whilst allowing a collapsible structure.

To enable quick inflation the vertices of the octahedra may be cut away slightly (not shown).

Figure 10 illustrates that, in this case, when the reflector 7 is fully collapsed, the mechanism for which is shown in Figures 4-9, it forms a planar triangle 7b enclosed within the internal faces of 13 and 14. This may be further reduced in size by folding along the lines denoted H and G in Figure 10. This results in the planar square structure 7c illustrated, which itself may be folded about the line J to form a compact

rectangular package 7d that may be easily stored in, for example, a small pocket on a life jacket (not shown).

Figure 11 illustrates the mechanism by which the structure of the radar reflector 7 may be maintained if suspended beneath a balloon containing lighter than air gas 9, as shown in Figure 1 a. The flexible gas line 6 is tethered to the garment by means of the gas cylinder and valve (not shown). The flexible gas line is also fixed to the reflector 7 at the points marked 17, before passing through the apertures 18 in components 13 and 14. It is also fastened securely to the balloon 9 which when inflated with a lighter than air gas, for example helium, exerts a tension upon 6. This tension pulls the corner reflector into shape, from the collapsed folded structure as shown in Figure 10, through the partially collapsed structures illustrated in Figures 9 to 5 to the fully erect structure as given in Figure 2. The flexible gas line 6 is fixed such that the reflector 7 is suspended at a reasonable height above the person 1, as shown in figure la.

Figure 12 illustrates a further mechanism by which the structure of the radar reflector 7 may be maintained if suspended beneath a balloon 9 containing lighter than air gas, as illustrated in Figure la. The corner reflector 7 is anchored to the person 1 by the line 19. The balloon 9 is inflated by a separate mechanism but is connected to the corner reflector via a line 20. This line has a loop as detailed in Figure 12 that passes through the apertures 18 in components 13 and 14, and when under tension from the balloon pulls the radar reflector into shape, from the collapsed folded structure as shown in Figure 10, through the partially collapsed structure illustrated in Figures 9 to 5, to the fully erect structure as given in Figure 2.

When not in use the personal locator 11, incorporating the radar reflector 7, in its fully

collapsed and folded state 7d as detailed in Figure 10, is retained inside a small pocket

5, for example, on the shoulder of a life-jacket 4. The pocket 5 is held fast by an (11.,, "'1) easily released material, for example Velcro and also contains a separate balloon 9 if

required as in Figure 1 a. Also fixed to the life-jacket is a small cylinder of a lighter than air gas, for example helium, connected to a valve that opens automatically upon

prolonged immersion in water (not shown). The valve may be connected by a flexible gas line 6, either to a radar permeable envelope 10 containing the reflector 7 as shown in Figure 1 b, or initially to the radar reflector 7 and then a balloon 9 as illustrated in Figures 1 a and 11, or just to a balloon 9 with the radar reflector 7 separately tethered 20,19 to both balloon and life-jacket as shown in Figure 12. The line 6, or 19/20, should be of sufficient length that both the balloon 9 and the reflector 7, or combined balloon/reflector 10 are, when in use, kept at sufficient height above sea level 3 to be easily visible to radar. If, for the latter example, the wearer 1 of the life jacket 4 fell overboard into the sea 2, then the balloon would automatically inflate. The inflating balloon 9, or 10, would open the pocket 5 on the life jacket 4 and escape pulling the collapsed corner reflector 7d with it. When fully inflated the balloon, which would ideally be of a highly visible colour, exerts enough tension upon the reflector 7 to pull it into shape, via 7c, and 7b in Figure 10, and subsequently Figures 9 to 5 and also, maintain its fully opened shape as shown in Figures 2,4 and 1.

Claims

CLAIMS 1. A personal locator including a plurality corner radar reflector that collapses to occupy a small volume by means of one of the intersecting surfaces being divided perpendicularly over about half of its area and then folding about an axis of common intersection to give an essentially planar structure, which may then be reduced in size, by further folding.
2. A personal locator as described in Claim 1 where the collapsible corner reflector is contained within, or suspended beneath, a balloon that may be deflated and collapsed to occupy a small volume.
3. A personal locator as claimed in Claim 1, or Claim 2, where the inflating gas is lighter than air.
4. A personal locator as claimed in Claim 3 where the surfaces of the corner reflector are fabricated from a flexible radar reflective material.
5. A personal locator as claimed in any preceding claim incorporating other personal location aids such as flashing lights, or bright colours.
6. A personal locator substantially as herein described and illustrated in the accompanying drawings.