GB2057003A

GB2057003A - Dye for assisting detection of assailants, thieves and other miscreants, and apparatus for applying the dye

Info

Publication number: GB2057003A
Application number: GB8021252A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-06-27
Filing date: 1980-06-27
Publication date: 1981-03-25

Abstract

Assailants, thieves and other miscreants are marked with a mixture of a visible staining agent and a fluorescent staining agent visible under U.V. light only. The stains persist for many days facilitating detection of the person. The visible staining agent may be methyl violet or victoria blue and the fluorescent agent one or more of rhodamine, fluorescein or auramine dissolved in water. The hand-held emitter comprises a flexible plastics container 1 with a nozzle 5 which may be temporarily covered 11. The emitter may be refilled through hole 4 by unscrewing the nozzle. Alternatively the nozzle may be provided at one end of the container. The emitter may also be installed in buildings or vehicles to be operated remotely or automatically. <IMAGE>

Description

SPECIFICATION Dye primarily intended for use in assisting detection of assailants, thieves and other miscreants, and apparatus for applying the dye This invention relates to a dye primarily intended for use in assisting detection of assailants, thieves or other miscreants, and apparatus for applying the dye.

The present invention consists in a dye primarily intended for use in assisting detection of assailants, thieves or other miscreants, comprising a mixture of a visible staining agent and a fluorescent staining agent which is visible only under ultra-violet light.

The intention is that the dye should be used to mark an assailant, thief or other miscreant, his clothing or other associated object, during or directly after the misdeed.

Preferably, the visible staining agent is of an indelible type which cannot readily be removed.

Desirably, it should be able to withstand washing and be noticeable on the skin, for example, for at least three days. The fluorescent staining agent should remain effective for a longer period.

Preferably, it should remain detectable on the skin for at least five days, preferably seven days.

As the dye includes a visible staining agent the miscreant will be aware of the marking and it is expected that he would attempt to remove or conceal it. It will be very difficult, if not impossible, to remove the visible staining agent from any clothing marked with the dye. This applies to hair as well and it may be that the visible staining agent may only be removed by cutting off the hair that has been marked. The visible staining agent may be removed from the skin but only after much washing. When the visible staining agent has been removed or concealed, the miscreant would most probably be satisfied that the tell-tale marking had been completely removed or concealed, being quite unaware that the dye includes the normally invisible fluorescent staining agent as well.

However, the fluorescent staining agent could still be present or at least partially unconcealed and couid be detected if the miscreant were to be suspected of the misdeed and he, his clothing or other objects were to be examined under ultraviolet light.

The agents used in the dye should be such that they will not cause injury to the eyes or skin, although the agents, or one of them, or an irritant agent added to the dye, might be capable of causing some temporary physical discomfort.

Thus, if the dye is applied to the miscreant at the onset of or during his misdeed, the physical discomfort might deter him from continuing the misdeed.

Examples of staining agents which may be included in the dye are, as the visible staining agent: methyl violet and victoria blue, and, as the fluorescent staining agent: rhoda mine, fluorescein and a fluorescent aura mine. Other suitable agents may be used.

At least so far as the fluorescent staining agent is concerned, there may be a plurality of such agents in the dye. In a preferred dye, there is one visible staining agent and three different fluorescent staining agents. The likelihood of all traces of the fluorescent staining agents being removed or concealed readily and speedily is thus considerably reduced.

The staining agents may be miscible in water or in another suitable solvent.

The dye may be applied from a hand-held emitter, or from other kinds of emitters which may be directly or remotely controlled.

A hand-held emitter is preferably adapted to emit the dye in the form of a jet because the dye can be projected a substantial distance and it can be directed with a reasonable degree of accuracy so that it facilitates application of the dye to the target, and reduces the likelihood of unintentional marking of other people or articles. Applied as a jet the dye will normally produce a dense mark which will add to the difficulty of its removal or concealment. The emitter may, for example, comprise a container which is flexible, or has a flexible part, and has a nozzle from which the dye is emitted as a jet upon the application of compressive hand force to the container or to the flexible part. The dye may alternatively be emitted asa spray, for example from an aerosol.Applied as a spray the dye would be spread over a wider area than a je and it is possible that people and/or articles other than those intended to be marked may be marked with the dye, which is less desirable.

A preferred form of hand-held emitter for the dye comprises a cylindrical container of a selfsupporting, flexible and impermeable, material, which container is charged with the dye, is of a size small enough to be held in the closed or substantially closed hand of an adult person and be substantially concealed when so held. The emitter may have a nozzle at one end, or it may have a nozzle at the side which is shaped and dimensioned to protrude between two fingers of the hand in which the container is held for the emission of the dye on application of compressive force on the container by the said hand.

It is envisaged that the dye may also be applied from emitters which are not held in the hand but are installed as fittings, or as fixtures, in buildings, vehicles or other places. For example, the emitters may be provided at doorways and windows of buildings, and be adapted to be operated by remote control, or automatically upon unauthorised opening-of the doors or windows, to emit the dye into the doorways or window openings.

In one embodiment a dye in accordance with the invention comprises one visible staining agent and three fluorescent staining agents mixed in water. The visible staining agent is methyl violet and the fluorescent staining agents are auramine, rhoda mine and fluorescein. The dye dries quickly when it is applied. The dye will be visible in daylight and under artificial light. It will in fact fluoresce to some extent under artificial lighting so that it will be difficult for anyone or anything marked with the dye to be un-noticed even at night. The visible staining agent may eventually be removed from the skin by repeated and vigorous washing in soap and water, but it is not readily removable and normally the visible staining agent would be noticeable on the skin for at least two to four days.The fluorescent staining agent would usually still remain, however, and would be detectable under ultra-violet light for at least seven to ten days. The dye may be applied by any suitable emitter.

An embodiment of a hand-held emitter by means of which the dye may be applied is shown in the accompanying drawings, in which: Figure I is an axial section through the emitter, and Figure 2 is a perspective view of the emitter held in the hand and in use.

The emitter comprises a moulded plastics, hollow cylindrical container 1 for the dye which has convexly rounded ends 2 and is formed midway along its circumferential wall with an internally screw threaded cylindrical spigot 3 which projects radially from that wall. An aperture 4 opens through the circumferential wall of the container axially into the spigot. A nozzle 5 of externally screw threaded drum form is screwed into, and is contained within, the spigot 3. The nozzle 5, which is also moulded from plastics has an outer end wall 6 with several outlets 7 for intense discharge of the dye in the form of a jet, and an inner end wall 8 from which a flexible feed tube 9 extends into the container 1 through the aperture 4. The bore of the feed tube communicates with an opening 10 in the centre of the inner end wall 8, which is otherwise imperforate.The feed tube extends across most of the diameter of the container. A cap 11 fits over the spigot, possibly with a snap action, to close off the nozzle when it is not required to be used.

The container 1 is flexible so that it can be readily compressed by hand to expel dye under pressure through the feed tube to the nozzle at the outer end wall of which it is discharged as a jet.

The container is dimensioned to be small enough to be held in the closed, or substantially closed, hand of an adult person, as shown in Figure 2, and be substantially concealed in the hand. As shown in Figure 2, the container can be held with the nozzle disposed between two fingers of the hand for the emission of the jet.

In one example of the emitter, the container is designed to hold up to 0.142 litres of dye in solution, and has a diameter of 32mm and is 90mm long. The spigot 3 containing the nozzle 5 has a diameter of 1 2mm and is 6mm long. A jet of the dye can be projected in a substantially straight line for a distance of up to 2.5 to 3.0m when the container is squeezed hard. Because of its small size the emitter may be carried quite conveniently in a pocket or handbag until required for use.

The container is charged, and can be re charged, with dye by screwing the nozzle out of the spigot and filling the container with the dye through the aperture 4.

Instead of being at the side of the container, the nozzle may be at one end of the container. The container may still be of a size which enables it to be substantially concealed in the hand, just the nozzle projecting from one end of the hand, usually adjacent the thumb.

Claims

1. A dye primarily intended for use in assisting detection of assailants, thieves or other miscreants, comprising a mixture of a visible staining agent and a fluorescent staining agent which is invisible or substantially invisible except when viewed under ultra-violet light.

2. A dye according to Claim 1 wherein the visible staining agent withstands washing and remains visible on the skin of a person for at least three days.

3. A dye according to Claim 1 or Claim 2 wherein the fluorescent staining agent withstands washing and remains detectable on the skin of a person for at least five days.

4. A dye according to any preceding claim wherein the visible staining agent is methyl violet.

5. A dye according to any of Claims 1 to 3 wherein the visible staining agent is victoria blue.

6. A dye according to any preceding claim wherein the fluorescent staining agent is rhodamine.

7. A dye according to any of Claims 1 to 5 wherein the fluorescent staining agent is fluorescein.

8. A dye according to any of Claims 1 to 5 wherein the fluorescent staining agent is a fluorescent auramine.

9. A dye according to any preceding claim wherein there is a plurality of fluorescent staining agents.

10. A dye according to any of Claims 1 to 5 wherein there are three fluorescent staining agents being rhoda mine, fluorescein and a fluorescent aura mine.

11. A dye according to any preceding claim including an irritant agent which is capable of causing temporary physical discomfort when applied to the person.

12. A dye according to any preceding claim in which the staining agents are mixed with water.

1 3. An emitter including a dye as claimed in any preceding claim.

14. A hand-held emitter including a dye as claimed in any of Claims 1 to 14.

1 5. A hand-held emitter according to Claim 14 comprising a container for the dye which is flexible or has a flexible part, and a nozzle from which the dye is emitted upon application of compressive hand pressure to the container or to the flexible part.

16. A hand-heid emitter according to Claim 15 wherein the nozzle is adapted to cause the dye to be emitted as a jet.

1 7. A hand-heid emitter according to Claim 14 or Claim 1 5 comprising a cylindrical container of a self-supporting, flexible and impermeable, material, which container is charged with the dye, is of a size small enough to be held in the closed or substantially closed hand of an adult person and be substantially concealed when so held, and which has a nozzle at the side which is shaped and dimensioned to protrude between two fingers of the hand in which the container is held for the emission of the dye on application of compressive force on the container by the said hand.

18. A hand-held emitter according to any of Claims 14 to 17 wherein a cap is removably fitted over the nozzle.

19. A hand-held emitter according to any of Claims 14 to 18 wherein the container has an internally screw threaded spigot from which an aperture opens into the interior of the container, the nozzle is externally screw threaded complementarily to and is engaged in the spigot, and a feed tube extends from the nozzle through the aperture into the container whereby the dye is expelled from the container to the nozzle when the container is compressed.

20. A hand-held emitter including a dye as claimed in any of Claims 1 to 12 and substantially as described herein with reference to and as illustrated by the accompanying drawings.