GB2380067A

GB2380067A - Modular passive radar reflector for watercraft

Info

Publication number: GB2380067A
Application number: GB0216386A
Authority: GB
Inventors: Paolo Ferrari
Original assignee: TR EM Srl
Current assignee: TR EM Srl
Priority date: 2001-07-19
Filing date: 2002-07-15
Publication date: 2003-03-26
Anticipated expiration: 2022-07-15
Also published as: GB0216386D0; GB2380067B; ITBO20010063V0; ITBO20010063U1

Abstract

A modular passive radar reflector for watercraft, comprising a plurality of mutually connected reflective metallic laminae (3) mutually connected and arranged along three mutually intersecting perpendicular planes, and a central core (2) provided with slots arranged along three mutually perpendicular planes to accommodate the laminae (3).

Description

MODULAR PASSIVE RADAR REFLECTOR FOR WATERCRAFT The present invention relates to a modular passive radar reflector for watercraft.

Passive radar reflectors are generally known in the nautical sector and are used to search for and locate scarcely reflective watercraft that accordingly cannot be otherwise detected by a radar. Since these reflectors must define, by signal reflection, the position of the watercraft wherever it may be, they are usually constituted by surfaces orientated along three planes that are mutually perpendicular in space. In this manner, the reflector is capable of reverberating a signal arriving from any direction.

A passive radar reflector for watercraft is constituted by a plurality of reflective metallic laminae, which are preferably semicircular and are mutually interlocked along three mutually perpendicular planes. These laminae can be rigidly coupled to a support or can be supported by ropes stretched on the mast.

To be installed, such radar reflector must be assembled by following a specific procedure, since the various metallic laminae can be mutually interlocked only in a specific order. This entails, in addition to constructive complexity of the reflector, the need to dedicate time to its setup.

It would be desirable to provide a modular passive radar reflector for watercraft that can be assembled and installed rapidly and simply, that is capable of reflecting effectively and safely signals that arrive from a radar in order to facilitate searching for and locating said watercraft., and that is simple, relatively easy to provide in practice, safe in use, effective in operation, and relatively low in cost.

According to the present invention there is provided

a modular passive radar reflector for watercraft, comprising a plurality of mutually connected reflective metallic laminae arranged along three mutually intersecting perpendicular planes, characterized in that it comprises a central core provided with slots that are arranged along three mutually perpendicular planes and are suitable to accommodate said laminae.

Further characteristics and advantages will become better apparent from the following detailed description of a preferred but not exclusive embodiment of a modular passive radar reflector for watercraft according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a perspective view of a modular passive radar reflector according to the invention; Figure 2 is a perspective view of a radar reflector in which some of the reflective metallic laminae have been removed; Figure 3 is a perspective view of the central core of the reflector according to the invention; Figure 4 is a transverse sectional view of the central core; Figure 5 is a plan view of a reflective metallic lamina; Figures 6,7, 8,9, 10,11 and 12 are plan views, lateral elevation views, and perspective views of constructive details of the radar reflector.

With reference to the figures, the reference numeral 1 generally designates a passive radar reflector for watercraft. The reflector according to the invention comprises a central core 2 provided with twelve reflective metallic laminae 3, which are arranged along three perpendicular planes and are connected, at their intersection points, by six protective caps 4.

As shown by Figures 3 and 4, the central core 2 is constituted by three disks 5 made of synthetic material, which mutually intersect along three perpendicular planes. Each one of the disks 5 is obtained by arranging side by side two circular plates 6 that are connected, on their respective facing

bases, by two mutually perpendicular ribs 7 that intersect each other at the center of the disk. This forms, for each disk, four slots 8 that are shaped substantially like circular sectors. Each disk 5 further has, at each slot 8, a hole 9 that passes through both circular plates 6. The central core 2 is completed by a bush 10 that defines a cylindrical channel lOa. The bush is rigidly coupled to the three disks 5, and its axis passes through the common center of the disks and is preferably set at a 45 angle with respect to the three perpendicular planes formed by the disks.

Each lamina 3, shown in Figure 5 and made for example of polished reflective light metal alloy, is substantially shaped so as to constitute a quadrant, since it is provided with two mutually perpendicular sides 11 and with an arc-like edge 12. At its vertex, the lamina 3 has a chamfer 13 and is provided, on the sides 11, with two recesses 14. On the arc-like edge 12 of the lamina there are, at the opposite ends, two slits 15, which are formed at an angle so that each one protrudes toward the respective side 11. An opening 16 is formed proximate to the chamfer 13.

The protective cap 4, shown in Figures 6, 7 and 8, is constituted by two flattened strips 17 made of synthetic material, which mutually intersect so as to form a substantially cross-like shape, defining two planes of symmetry of the cap. Two open slots 18 are formed in the strips, run along them from end to end and mutually intersect, defining a concave bottom 19. On each strip, in regions that are mirror-symmetrical with respect to the plane of symmetry formed by the other strip, there are two teeth 20 that protrude from the bottom 19 and are inclined toward the plane.

The metallic laminae 3 enter the slots 8 of the central core 2 and the recesses 14 abut against the ribs 7 of the disks 5. The laminae are therefore in mutual contact, four by four, along the respective sides 11. The protective caps 4 are arranged peripherally at the sides 11 by interlocking the teeth 20 in the slits 15 of each lamina.

With reference to Figure 9, the metallic laminae 3 are locked on the

central core 2 by interposing elastically expanding rivets 21 that can be inserted through the holes 9, which once assembly has been completed are coaxial to the opening 16. The rivets 21 are constituted by a cylindrical stem 22 provided with a head 23. The stem has a conical cavity 24 that is coaxial thereto and a plurality of longitudinal notches 25. A cylindrical pin 26 engages in the cavity 24 and is suitable to widen the stem by way of the inverse taper of the cavity 24.

As shown in Figures 10 and 12, the reflector is completed by supporting means 27 for positioning in regions that facilitate signal reflection, such as for example one of the masts of the watercraft. Such supporting means comprise a stand that consists of a base 27a provided with a stem 27b, which ends with a threaded bar 27c, on which the central core is fitted through the cylindrical channel lOa of the bush 10. The bush is locked by two triangular washers 28 that are locked by a nut 29.

As an alternative, with reference to Figure 11, the reflector can be hung by means of a pair of eyes 30 fixed to the ends of a traction element 31, which also can be inserted in the cylindrical channel lOa. Two spring clips 32, connected to two ends of a rope 33, engage in the eyes.

The method of use of the radar of the invention is as follows. It is positioned on the watercraft externally, in a sufficiently exposed point, and allows a radar to search for the watercraft.

It has thus been shown that the invention achieves the intended aim and objects. In particular, it can be assembled easily and rapidly, providing effective and reliable reflection of the signals that arrive from the radar.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

All the details may further be replaced with other technically equivalent ones.

In practice, the materials used, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope

of the appended claims.

Claims

1. A modular passive radar reflector for watercraft, comprising a plurality of mutually connected reflective metallic laminae mutually connected and arranged along three mutually intersecting perpendicular planes, characterized in that it comprises a central core provided with slots that are arranged along three mutually perpendicular planes and are suitable to accommodate said laminae

2. The radar reflector according to claim 1, characterized in that said central core comprises three disks made of synthetic material which mutually intersect along three perpendicular planes, said disks being constituted by two facing circular plates that are joined by two perpendicular ribs that mutually intersect in the center of said disks, said ribs forming, on each one of said disks, four slots that are substantially shaped like a circular sector.

3. The radar reflector according to one of claims 1 and 2, characterized in that said central core comprises a bush that defines a cylindrical channel, said bush having an axis that passes through the common center of said disks, supporting means for said reflector being engaged in said cylindrical channel

4. The radar reflector according to one of claims 1 to 3, characterized in that said reflective metallic laminae are substantially shaped like a quadrant, comprise two mutually perpendicular sides and an arc-like edge, and have, at the vertex formed by said sides, a chamfer and two recesses formed respectively on said sides, said recesses being suitable to engage, following the insertion of said laminae in said slots, on said ribs of said disks

5. The radar reflector according to one of claims 1 and 4, characterized in that said metallic laminae comprise, at the opposite ends of said arc-like edge, two slits that are inclined toward the respective side and in that there are six protective caps that can be arranged peripherally at

the six lines of mutual contact of said sides of said laminae

6. The radar reflector according to one of the preceding claims, characterized in that said protective caps comprise two flat strips that mutually intersect so as to form a substantially cross-like shape, each one of said strips being provided with an open slot that runs from end to end, each one of said strips having, on the bottom of said slot, two teeth that are suitable to engage in said slits of said laminae in order to retain said laminae at right angles to each other.

7. The modular passive radar reflector for watercraft substantially as described with reference to and as illustrated by the accompanying drawings.