GB2039936A

GB2039936A - Marker lamps

Info

Publication number: GB2039936A
Application number: GB8002074A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-01-22
Filing date: 1980-01-22
Publication date: 1980-08-20

Abstract

The lamp may have a reflective surface over part of the encapsulation and pyramidal facets to control light direction. The lamp may be provided with lugs or holes for securing it to underwater oil pipelines, passageways and roads. <IMAGE>

Description

SPECIFICATION Marker lamps This invention relates to lamps primarily marker lamps for use in general identification marking of routes, for example roads, and for identification of underwater oil pipelines.

The invention involves the complete encapsulation in transparent plastics material of the small radio-active light capsules known under various trade names such as "micro-light" and "beta-light".

These lights comprise a small sealed glass capsule, the hollow inside surface of which is coated with phosphor, and which contains tritium or similar radioactive gas. Radiation given off by the gas excites the phosphor coating which in turn produces light, and the half-life of this reaction can be of the order of 15 to 20 years. The capsule thus appears from the outside to glow, the light emitted being omnidirectional.

Suitable materials for encapsulation of the lamp capsule are acrylic, polyester, styrene, epoxy, CR39, or similar clear plastics material.

The outside surface of the solid encapsulation may be shaped to produce particular desired reflections for particular uses. In addition, the outside surface of the encapsulation may be partially covered with reflective material to concentrate' the emitted light in a particular direction or directions. Such reflective covering may, for example, take the form of silvering by vacuum deposition on the outside surface of the encapsulation of aluminium, gold or silver. A cheaper, but less satisfactory, alternative would be to paint the outside surface of the encapsulation with reflective paint.

In a preferred embodiment of the invention, both shaping of the outside surface of the encapsulation and partial silvering are used to achieve particular light patterns for particular applications.

In order that the invention may be better understood, several embodiments thereof will now be described by way of example only and with reference to the accompanying drawings in which Figure 1 is a perspective view of one embodiment of a lamp according to the present invention; Figures 2 and 3 are cross sectional views of different embodiments of lamps according to the present invention.

Referring to Figure 1, there is shown a basic form of the invention in which a beta light 1 is encapsulated in a solid clear acrylic encapsulation 2. The encapsulation 2 is rectangular in shape, and the lamp 1 is placed in the approximate geometric centre of the block. The lamp may, however occupy other positions within the block, provided always that it is completely encapsulated. The encapsulation results in an extremely rugged form of lamp which can be used in exceptionally arduous conditions.

The shape of the external surface of the encapsulation will be dictated by the circumstances under which it is to be used. The encapsulation need not be rectangular as shown in Figure 1, but could have a square or circular cross section. Two further suitable cross sections are shown by way of example in Figures 2 and 3.

Figure 3 also shows a lamp in which partial silvering is used to concentrate the light output from the beta light 1 in a particular direction. The top surface of the section is planar, and is not silvered.

The remaining surfaces are each silvered as shown under reference 3 to direct light upwards in the same manner as a conventional lamp reflector. The shape of the lamp shown in Figure 3 in plan would be rectangular.

The lamp shown in Figure 3 would find particular application as a marker lamp in underwater oil pipe lines, the lamps being attached at intervals along the pipe so that the route of the pipe can be clearly seen even in the darkest water. Non silvered varieties of lamp could be used as marker lights for underwater cable laying, the encapsulation thence being drilled to accept a rope for tying the lamp. It would even be feasable to use the lamp as fish lures, for example by placing them in lobster pots to attract the fish.

In order to prevent marine fouling eventially obscuring the output of lamps used for long periods underwater it is envisaged that the structure could be made slightly radioactive in order to prevent marine iife from settling on the light emitting surface or surfaces.

In view of its robustness, the lamp of this invention will find application in areas where damage or corrosion is likely. Underwater applications have already been mentioned; however, it is envisaged that the lamp could find a wide variety of other uses, for example lighting dark corridors and passages where damage by vandals is a problem.

In all the embodiments described above, the beta light has been shown of elongate form. This shape happens to be convenient for many of the applications envisaged for this lamp. However, several other shapes are available, and may indeed be preferred in particular circumstances. Also, the outer surface of the light emitting portions of the encapsulation have been shown smooth. They may in fact be given a satin finish a diffuse light is desired, or alternatively a multi pyramidal surface, as used to direct light in small vehicle lamps.

Integral lugs may be formed on the encapsulation for fixing or hanging purposes. Alternatively, as mentioned above, an aperture or apertures may be formed in the encapsulation itself in oderto allow the lamp to be hung or fixed as desired.

1. A marker lamp comprising a block of transparent plastics material and, encapsulated within said block, a radioactive light source in the form of a capsule containing radioactive material and a light emitting material arranged to be excited to produce light by virtue of radiation given off by said radioactive material.

2. A marker lamp as claimed in claim 1 wherein the block completely encapsulates the capsule, thus protecting the same from damage.

3. A marker lamp as claimed in claim 2 wherein the plastics material is acrylic.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Marker lamps This invention relates to lamps primarily marker lamps for use in general identification marking of routes, for example roads, and for identification of underwater oil pipelines. The invention involves the complete encapsulation in transparent plastics material of the small radio-active light capsules known under various trade names such as "micro-light" and "beta-light". These lights comprise a small sealed glass capsule, the hollow inside surface of which is coated with phosphor, and which contains tritium or similar radioactive gas. Radiation given off by the gas excites the phosphor coating which in turn produces light, and the half-life of this reaction can be of the order of 15 to 20 years. The capsule thus appears from the outside to glow, the light emitted being omnidirectional. Suitable materials for encapsulation of the lamp capsule are acrylic, polyester, styrene, epoxy, CR39, or similar clear plastics material. The outside surface of the solid encapsulation may be shaped to produce particular desired reflections for particular uses. In addition, the outside surface of the encapsulation may be partially covered with reflective material to concentrate' the emitted light in a particular direction or directions. Such reflective covering may, for example, take the form of silvering by vacuum deposition on the outside surface of the encapsulation of aluminium, gold or silver. A cheaper, but less satisfactory, alternative would be to paint the outside surface of the encapsulation with reflective paint. In a preferred embodiment of the invention, both shaping of the outside surface of the encapsulation and partial silvering are used to achieve particular light patterns for particular applications. In order that the invention may be better understood, several embodiments thereof will now be described by way of example only and with reference to the accompanying drawings in which Figure 1 is a perspective view of one embodiment of a lamp according to the present invention; Figures 2 and 3 are cross sectional views of different embodiments of lamps according to the present invention. Referring to Figure 1, there is shown a basic form of the invention in which a beta light 1 is encapsulated in a solid clear acrylic encapsulation 2. The encapsulation 2 is rectangular in shape, and the lamp 1 is placed in the approximate geometric centre of the block. The lamp may, however occupy other positions within the block, provided always that it is completely encapsulated. The encapsulation results in an extremely rugged form of lamp which can be used in exceptionally arduous conditions. The shape of the external surface of the encapsulation will be dictated by the circumstances under which it is to be used. The encapsulation need not be rectangular as shown in Figure 1, but could have a square or circular cross section. Two further suitable cross sections are shown by way of example in Figures 2 and 3. Figure 3 also shows a lamp in which partial silvering is used to concentrate the light output from the beta light 1 in a particular direction. The top surface of the section is planar, and is not silvered. The remaining surfaces are each silvered as shown under reference 3 to direct light upwards in the same manner as a conventional lamp reflector. The shape of the lamp shown in Figure 3 in plan would be rectangular. The lamp shown in Figure 3 would find particular application as a marker lamp in underwater oil pipe lines, the lamps being attached at intervals along the pipe so that the route of the pipe can be clearly seen even in the darkest water. Non silvered varieties of lamp could be used as marker lights for underwater cable laying, the encapsulation thence being drilled to accept a rope for tying the lamp. It would even be feasable to use the lamp as fish lures, for example by placing them in lobster pots to attract the fish. In order to prevent marine fouling eventially obscuring the output of lamps used for long periods underwater it is envisaged that the structure could be made slightly radioactive in order to prevent marine iife from settling on the light emitting surface or surfaces. In view of its robustness, the lamp of this invention will find application in areas where damage or corrosion is likely. Underwater applications have already been mentioned; however, it is envisaged that the lamp could find a wide variety of other uses, for example lighting dark corridors and passages where damage by vandals is a problem. In all the embodiments described above, the beta light has been shown of elongate form. This shape happens to be convenient for many of the applications envisaged for this lamp. However, several other shapes are available, and may indeed be preferred in particular circumstances. Also, the outer surface of the light emitting portions of the encapsulation have been shown smooth. They may in fact be given a satin finish a diffuse light is desired, or alternatively a multi pyramidal surface, as used to direct light in small vehicle lamps. Integral lugs may be formed on the encapsulation for fixing or hanging purposes. Alternatively, as mentioned above, an aperture or apertures may be formed in the encapsulation itself in oderto allow the lamp to be hung or fixed as desired. CLAIMS

4. A marker lamp as claimed in claim 2 wherein the block takes the shape of a circular section bar with the capsule encapsulated in the approximate geometric centre of the block.

5. A marker lamp as claimed in claim 2 wherein the block takes the shape of a hexagonal section bar with the capsule encapsulated in the approximate geometric centre of the block.

6. A marker lamp as claimed in either one of claims 2,4 or 5 wherein the exterior surface of the block has a satin finish to provide a diffuse light output.

7. A marker lamp as claimed in either one of claims 2,4 or 5 wherein the exterior surface of the block has a multi-pyramidal finish in order to direct the light output in a desired manner.

8. A marker lamp as claimed in claim 2 wherein partial silvering is provided on the surface of or within the block in order to direct the light output in a particular direction.

9. A marker lamp as claimed in claim 2 wherein a through-hole is formed in the block in order to allow a fixing rope or chain to be passed through.

10. A marker lamp as claimed in claim 2 wherein lugs are formed on the block for fixing purposes.

11. A marker lamp substantially as hereinbefore described with reference to the accompanying drawings.