US3152329A

US3152329A - Collapsible octahedral corner reflector

Info

Publication number: US3152329A
Application number: US137149A
Authority: US
Inventors: Lowery Peter Albert; Richards Harold Edmu Griffiths; Pook Bernard Thomas Triggs
Original assignee: Chemring Ltd
Current assignee: Chemring Ltd
Priority date: 1961-09-11
Filing date: 1961-09-11
Publication date: 1964-10-06
Anticipated expiration: 1981-10-06

Description

Oct. 6, 1964 FIG.4.

P. A. LOWERY ETAL 3,152,329

COLLAPSIBLE OCTAHEIDRAL CORNER REFLECTOR Filed Sept. 11, 1961 02L 2 INVENTORSI "M 2 BYM, M I M 9'- ATTORN5 United States Patent "ice 3,152,329 CGLLAPSIBLE OCTAHEDRAL CORNER REFLECTOR Peter Albert Lowery, Retford, Harold Edmund Grilfiths Richards, Mudeford, near Christchurch, and Bernard Thomas Triggs Pools, London, England, assignors to Chemriug Limited, Thornton Heath, England, a British company Filed Sept. 11, 1961, Ser. No. 137,149 3 Claims. (Cl. 34318) This invention relates to radar reflectors of the corner type.

A known collapsible corner reflector comprises four triangular panels and a single square panel all of flexible reflecting material. A collapsible supporting framework is provided for supporting the triangular panels in perpendicular planes and for supporting the square panel in a plane at right angles to the planes in which the triangular panels are disposed. The framework includes a central post, a member slidable on the post, four supporting members each pivoted at one end to the slidable member, and means for selectively securing the slidable member against sliding movement on the post at a position adjacent the square panel. The collapsing of the framework is effected by moving the slidable member towards those apices of the triangular panels which are remote from the square panel.

According to the present invention we provide an octaredral reflector of the type referred to comprising a single square panel flexible reflecting material as a base, four triangular panels of reflecting material disposed at 90 to one another above the base to form four corners of the reflector and four triangular panels of reflecting material disposed at 90 to one another below the base to form the other four corners of the reflector, four arms for supporting the retaining panels in their operative positions and a central post to which the arms are pivotally connected at one end, the arrangement being such that the various parts of the reflector may be folded substantially into parallelism with the central post when the reflector is stored.

Also according to the invention, we provide an octahedral reflector of the type referred to which may be folded up and opened out as desired, the reflective material being secured to the top of a central post, to four arms pivotally mounted at or near the center or midpoint of said post on a collar on the post and to a second collar slidable on the post below the center from a closed position adjacent to the center to an open position near the bottom, tensioning wire being provided to hold the unsupported sides of the reflective material in position.

The base and the panels are preferably made of metalcoated plastic mesh e.g. silvered nylon and the post and arms may be made of metal e.g. light metal such as aluminium or stronger metal such as stainless steel.

One embodiment of the invention will now be described in more detail by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a perspective view of the reflector.

FIGURE 2 is a detail view of the means of connecting the arms to the post,

FIGURE 3 is a detail view of the bottom of the post, and

FIGURE 4 is a sectional view of the collapsible reflector disclosing a modified form of the slidable collar.

In this embodiment the central post 1 consists of a single metal tube which extends from end to end of the reflector. At a position near the center of the post 1 a collar 2 is fixed. Four arms 3 are pivotally connected to the fixed collar in such a Way that they can be folded up against the post or can be extended outwards at 90 3,152,329 Patented Oct. 6, 1964 thereto. Reflective mesh material 4 is hemmed and shaped and is secured into position to provide the base 4, the four panels 5 above the base, and the four panels 6 below the base. To do this the mesh material may be provided with a sleeve 9 at the center through which the post 1 is extended. Each arm is also extended down a sleeve 10 provided for this purpose. In addition hems 11 are provided to extend from the outer end of each arm to the top of the post, i.e., along the free side of each triangular panel 5 and a wire 12 is passed along the hems and through slots 13 or the like at the end of each arm and at the top of the post, the purpose of the wire being to assist in tensioning the reflector when it is opened out.

The four corners below the base are formed in much the same way as the four corners above the base but instead of being fixed to the bottom of the post, triangular panels 6 of mesh material are secured to a slidable collar 7 on the central post 1. When the reflector is collapsed the slidable collar 7 lies close to the fixed collar 2, but when the reflector is opened out as in FIGURE 1 the slidable collar 7 is at the lower end of the central post :1 so that the triangular panels 6 forming the corners below the base 4 are in their operative position. A releasable catch 8 is provided at the lower end of the post 1 to hold the slidable collar 7 in the open position. Suitable strengthening means may be provided for the reflective material where required. For example, extra material 14- may be provided where the material is attached to the top of the post 1, and to the end of each arm 3. If desired the central post 1 may be made in two parts so that it can be dismantled for packing. Two or more of these octahedral reflectors may be used together to form a cluster.

To open out the reflector, the arms 3 are pivoted on the fixed collar 2 until they are at to the post 1 and the slidable collar 7 is moved down the post 1 until it is engaged with the catch 8. In this position one side of each

triangular panel

5 and 6 is supported by the central post 1, one side by an arm 3, and one side by a wire 11 so that each triangular panel has a rigid support on two sides. The arms 3 form diagonal supports for the base and the sides of the base are held in position on the arms by wire. In this way a very elfective octahedral corner reflector is provided. To fold up the reflector the catch 8 is released, e.g., by manual pressing, the slidable collar 7 is moved up the central post 1 and the arms 3 are folded up so that the outer end of each arm 3 lies adjacent to the top of the central post 1. Naturally the tensioning wire 11 may be a continuous length which is extended along one hem round the end of an arm, along another hem, and so on; for this purpose the ends of the arms and the top of the central post may be slotted as at 13.

We have therefore provided an octahedral corner reflector of the type referred to which maybe folded up and opened out as desired. The reflective material is secured to the top of a central post, to four arms pivotal. y mounted at the center on a collar on the post, and to a second collar slidable on the post below the center from a closed position adjacent to the center to an open position near to the bottom. Tensioning wires are provided to hold the unsupported side of the reflective material in position.

Instead of being fixed, e.g., by a rivet at a position near to the center of the post the collar 2 may be held in position by a spring clip 15 and if desired a clip 16 may be used giving two or more positions for the collar so that it may be adjusted in the same manner as the snap catch 8 which may also have two or

more positions

8a, 8b and 80.

In another construction spring means 17 may be provided to make the reflector self-erecting. To achieve this result the center post 1 may be extended beyond the catch 8 for a distance to enable springs 18 to operate over a suflicient length to erect the reflector. These springs may extend between the slidable collar to a fixed point 19 on the extended center post so that they draw the slidable collar on to its spring catch. In this construction the reflector may erect automatically as soon as it is freed from restraint.

What We claim is:

1. A collapsible octahedral corner reflector comprising: a central supporting post; a first collar on said post movable to at least two positions near the midpoint of said post; a plurality of spring clips defining said positions; four supporting arms at right angles to each other each pivotably attached to one end to said first collar; a second collar slidably mounted on said post from a closed position adjacent and below said first collar to an open position near the bottom of said post; radar-reflective flexible material shaped to provide a square base panel having its corners secured to the outer ends of said arms, having its center secured to said first collar and having its diagonal portions secured to said arms along their length; four right-angled triangular upper panels of radar-reflective flexible material symmetrically disposed above said base panel between said post and said arms, each of said upper panels having its right-angled corner secured to said first collar, having its second corner secured to the end of the arm supporting it and having its third corner secured to the top of said post; four right-angled triangular lower panels of radar-reflective flexible material symmetrically disposed below said base panel between said post and said arms, each of said lower panels having its right-angled corner secured to said first collar, having its second corner secured to the end of the arm supporting it and having its third corner attached to said second collar; each of said triangular panels having a hem in its hypotenuse side and a tensioning wire passing through the hem, the tensioning wire in said upper panels extending from said post to said arms and the tensioning wire in said lower panels extending from said arms to said second collar; and means for adjustably securing said second collar on said post in the open position whereby said arms are spread in a plane at right angles to said post.

2. A corner reflector according to claim 1 further comprising spring means attached to said second collar and to a fixed point on said center post, said spring means being effective to move said second collar along the post to bring the pivoted arm's into a plane at right angles to the post.

3. A corner reflector according to claim 1 wherein said radar-reflective material is metal-coated plastic mesh.

References Cited in the file of this patent UNITED STATES PATENTS 2,450,417 Bossi Oct. 5, 1948 2,534,710 Golian et a1 Dec. 19, 1950 2,604,644 Tilton July 29, 1952 2,639,426 McAuley et a1. May 19, 1953 FOREIGN PATENTS 746,300 Great Britain Mar. 14, 1956 812,376 Great Britain Apr. 22, 1959

Claims

1. A COLLAPSIBLE OCTAHEDRAL CORNER REFLECTOR COMPRISING: A CENTRAL SUPPORTING POST; A FIRST COLLAR ON SAID POST MOVABLE TO AT LEAST TWO POSITIONS NEAR THE MIDPOINT OF SAID POST; A PLURALITY OF SPRING CLIPS DEFINING SAID POSITIONS; FOUR SUPPORTING ARMS AT RIGHT ANGLES TO EACH OTHER EACH PIVOTABLY ATTACHED TO ONE END TO SAID FIRST COLLAR; A SECOND COLLAR SLIDABLY MOUNTED ON SAID POST FROM A CLOSED POSITION ADJACENT AND BELOW SAID FIRST COLLAR TO AN OPEN POSITION NEAR THE BOTTOM OF SAID POST; RADAR-REFLECTIVE FLEXIBLE MATERIAL SHAPED TO PROVIDE A SQUARE BASE PANEL HAVING ITS CORNERS SECURED TO THE OUTER ENDS OF SAID ARMS, HAVING ITS CENTER SECURED TO SAID FIRST COLLAR AND HAVING ITS DIAGONAL PORTIONS SECURED TO SAID ARMS ALONG THEIR LENGTH; FOUR RIGHT-ANGLED TRIANGULAR UPPER PANELS OF RADAR-REFLECTIVE FLEXIBLE MATERIAL SYMMETRICALLY DISPOSED ABOVE SAID BASE PANEL BETWEEN SAID POST AND SAID ARMS, EACH OF SAID UPPER PANELS HAVING ITS RIGHT-ANGLED CORNER SECURED TO SAID FIRST COLLAR, HAVING ITS SECOND CORNER SECURED TO THE END OF THE ARM SUPPORTING IT AND HAVING ITS THIRD CORNER SECURED TO THE TOP OF SAID POST; FOUR RIGHT-ANGLED TRIANGULAR LOWER PANELS OF RADAR-REFLECTIVE FLEXIBLE MATERIAL SYMMETRICALLY DISPOSED BELOW SAID BASE PANEL BETWEEN SAID POST AND SAID ARMS, EACH OF SAID LOWER PANELS HAVING ITS RIGHT-ANGLED CORNER SECURED TO SAID FIRST COLLAR, HAVING ITS SECOND CORNER SECURED TO THE END OF THE ARM SUPPORTING IT AND HAVING ITS THIRD CORNER ATTACHED TO SAID SECOND COLLAR; EACH OF SAID TRIANGULAR PANELS HAVING A HEM IN ITS HYPOTENUSE SIDE AND A TENSIONING WIRE PASSING THROUGH THE HEM, THE TENSIONING WIRE IN SAID UPPER PANELS EXTENDING FROM SAID POST TO SAID ARMS AND THE TENSIONING WIRE IN SAID LOWER PANELS EXTENDING FROM SAID ARMS TO SAID SECOND COLLARS; AND MEANS FOR ADJUSTABLY SECURING SAID SECOND COLLAR ON SAID POST IN THE OPEN POSITION WHEREBY SAID ARMS ARE SPREAD IN A PLANE AT RIGHT ANGLES TO SAID POST.