GB2284015A

GB2284015A - Post box

Info

Publication number: GB2284015A
Application number: GB9420864A
Authority: GB
Inventors: John Kelly Fox
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-10-12
Filing date: 1994-10-12
Publication date: 1995-05-24
Anticipated expiration: 2014-10-12
Also published as: GB9321048D0; GB9420864D0; GB2284015B

Abstract

A post box comprises a defence mechanism, which includes an audible alarm 22, a closure flap 42, a fire extinguisher and a liquid dye discharge system, for protecting the box in the event of an attack. The defence mechanism is activated in response to a signal from a sensor means for sensing the attack. The sensor means may be a heat sensor or a smoke detector for detecting a fire in the box or it may comprise a liquid detector. Once the sensor means has been activated the alarm 22 is sounded and the closure flap 42 is released to seal the box preventing further access by the attacker and starving any fire of oxygen. The dye discharge system is activated to mark the attacker to help in detection. The box is constructed of a fire resistant plastics and has a container portion for retaining liquids poured into the box. <IMAGE>

Description

A POST BOX This invention relates to a post box such for example as a letterbox or a postal authority pillar box.

Attacks on post boxes are a common occurrence. For example, arsonists and vandals often pour flammable liquids through letterboxes, and then set fire to the flammable liquids with a view to damaging homes and offices. Vandals also often put rubbish or unpleasant substances through letterboxes with a view to upsetting occupants of houses and offices. Sometimes the attack on the letterbox is malicious and sometimes the attack on the letterbox is more in the nature of a prank. In any event, damage is often incurred, together with owners of premises being upset and put to the inconvenience of having to rectify damage caused and to clear up mess.

Post boxes such for example as letterboxes and pillar boxes are vulnerable to attacks of the above mentioned type. It is an aim of the present invention to reduce this problem.

Accordingly, in one non-limiting embodiment of the present invention, there is provided a post box comprising a body, a slot in the body for enabling postal items to be inserted into the body, a door for enabling postal items which have been inserted into the body to be retrieved, at least one defence mechanism for protecting the post box consequent upon the post box being subject to an attack, and at least one sensor means for sensing the attack and for causing the defence mechanism to operate.

The attack on the post box that is sensed by the sensor means may be the receipt of the post box of obnoxious substance, for example a liquid for causing a fire, a liquid for causing staining, a burning piece of paper or rag, rubbish or faeces.

The post box may be a letterbox for securing to the the inside of a door adjacent a slot in the door through which letters are posted. The letterbox can be used in premises such for example as homes, offices and factories.

The post box may be an outside mountable post box, for example mountable on a post at the end of a garden or mountable on an outside wall of premises.

The post box may still further be a stand alone pillar box, for example of a type used by the postal authorities in the United Kingdom.

The body of the post box of the invention may be of any suitable and appropriate shape commensurate with the type of post box in question, for example a letterbox for internal use, a letterbox for external use, or a pillar box.

Usually, the post box will comprise a container portion for retaining liquids poured into the post box.

The container portion will usually be formed as an integral part of the body. If desired however the container portion may be a separately formed tray which is inserted into the body.

The sensor means may comprise a heat sensor which is such that it causes the defence mechanism to operate when the heat sensor senses heat. With such a heat sensor, the post box is able to take defensive action in the event of an arson attempt.

Alternatively or in addition, the sensor means may comprise a smoke detector which is such that it causes the defence mechanism to operate when the smoke detector detects smoke. This again enables the post box to take defence action in the event of an arson attempt.

Alternatively or in addition, the sensor means may comprise a liquid detector which is such that it causes the defence mechanism to operate when the liquid detector detects a liquid.

The liquid detector may operate by touch so that it operates when it is touched by the liquid. The liquid detector may thus be a float switch. Alternatively, the liquid detector may operate by sensing the smell of the liquid, for example petrol fumes or tar fumes.

The defence mechanism may comprise closure means for closing the slot in the body. Any fire in the body will thus be put out by being starved of oxygen. Any attempt to put further liquids or rubbish in the post box will thus be prevented once the post box is sealed.

The closure means preferably comprises a closure flap. The closure flap is preferably spring biased to a closed position, in which case the closure means preferably includes retainer means for retaining the closure flap in an open position, and release means for releasing the retainer means consequent upon the sensor means sensing the attack. The closure means may include lock means for keeping the closure means in the closed position during an attack.

Alternatively or in addition the defence mechanism may comprise fire extinguisher means for releasing a substance for putting out a fire in the post box.

The fire extinguisher means may be able to release a powder or a foam substance for putting out the fire in the post box.

Alternatively or in addition the defence mechanism may comprise alarm means for directing attention to the attack on the post box.

The alarm means may be an audio and/or visual alarm means. The alarm means may be a separate alarm means for the post box. When the alarm means is for use in premises, then the alarm means may be the alarm means of the premises, the post box being provided with connection means for connecting the post box to the alarm means of the premises.

Alternatively or in addition, the defence mechanism may comprise a dye discharge system. The dye discharge system can then be used to mark an attacker, thereby facilitating the apprehension of the attacker.

The dye discharge system may comprise a pressurised dye cannister which contains the dye. The dye may be a liquid or a powder. The die discharge system may alternatively comprise a pump for discharging the dye.

When a pump is used, the pump may be such that it is also able to be used for discharging a fire extinguishing substance inside the post box to put out any fire in the post box.

When the post box is a letterbox, then the letterbox may be made of a fire resistant plastics material. The plastics material may be a clear plastics material or a plastics material which is transparent in part. Generally, the post boxes of the present invention can be made of any suitable materials including metals, plastics materials, wood and resins.

The door will usually be a hinged door. Other types of doors may however be employed. The door is preferably provided with a handle and a lock. The door can be situated anywhere on the letterbox, for example in a back of the body or on top of the body.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 is a schematic side view of a post box in the form of a letterbox attached to the inside of a door; Figure 2 is a rear view of the post box and the door shown in Figure 1; Figure 3 is an enlarged side view of a second letterbox which is like that shown in Figure 1 and which is in an inactive state; Figure 4 is a side view of the letterbox shown in Figure 3 but in an activated state; Figure 5 is a schematic perspective view of a letterbox and illustrates the use of two dye discharge nozzles; Figure 6 is a schematic side view through the letterbox shown in Figure 5; Figure 7 is an enlarged side view like the bottom part of Figure 6 and illustrates the use of three dye discharge nozzles; ; Figure 8 shows the rear of a letterbox with a defence mechanism in the form of a closure flap, the closure flap being open; Figure 9 is a view like that shown in Figure 8 but shows the closure flap in its closed position; and Figure 10 shows a post box in the form of a pillar box which is under attack and which is defending itself.

Referring to Figures 1 and 2, there is shown a post box in the form of a letterbox 2 secured to the rear face 4 of a door 6. The door 6 has a front handle 8 and a rear handle 10. An arsonist 12 is shown pouring petrol into the letterbox 2 through a letterbox slot 16 in the door 6. The arsonist 12 is pouring the petrol 14 from a can 18 as shown, the can 18 having a spout 20 which has been put through the slot 16 and into the letterbox 2.

As shown in Figure 1, the letterbox 2 is in an active defending state and it is sounding an alarm 22 and it is spraying a coloured liquid dye 24 on to the legs and feet of the arsonist 12 in order to facilitate the identification and apprehending of the arsonist 12.

The post box 2 has a body 26, a slot 28 in the body 26 for enabling postal items to be inserted into the body 26, and a door 30 for enabling postal items which have been inserted into the body 26 to be retrieved.

The letterbox 2 has several defence mechanisms for protecting the letterbox 2 from the attack by the arsonist 12. A first defence mechanism is a liquid dye discharge system 32 including a discharge nozzle 34 for discharging the dye 24.

A second defence mechanism is an audio alarm means 36 for issuing the audio alarm 22.

As can be seen in Figure 1, the letterbox 2 is secured to the rear face 4 of the door 6 by screws 38 passing through side plates 40.

The letterbox 2 has a third defence mechanism in the form of a closure flap 42 for closing the slot 28 in the body 26. The closure flap 42 is described hereinbelow in more detail with reference to Figures 3 and 4.

During normal use of the letterbox 2 when it is not under attack, postal items can simply be posted through the registering slots 16, 28. The items of mail will then be in the letterbox 2 where they will rest on a mesh tray 44. The postal items can easily be collected from the tray 44 by opening the door 30 which is like a lid since it is mounted on the top part of the body 26.

The door 30 is hinged and it is preferably provided with a handle so that the door 30 can easily be lifted to its open position. If desired, the tray 44 may be a removable tray so that it can be lifted out of the body 26 when desired, for example for cleaning if the inside of the letterbox 26 has been vandalised with a staining liquid or with rubbish, or if the letterbox has had burning material placed in it. In order to contain a fire or staining liquid placed in the letterbox 2, the letterbox 2 is preferably formed to be fire resistant and watertight.

The door 30 is provided with a lock 46 for enabling the letterbox 2 to be locked from inside a house or other premises. The locking of the door 30 to the body 26 stops the arsonist 12 trying to bypass the letterbox 2 and feed the petrol or other material through the slots 16, 28 and then into the house or other premises by pushing open the door 30, for example using a flexible tube.

When the letterbox 2 is under attack by the arsonist 12, the alarm 22 will be caused to sound by sensor means including a trigger switch 48. The trigger switch 48 at the same time activates a motor of a pump 50 (see Figures 3 and 4) for causing the dye 24 to be discharged through the discharge nozzle 34.

Referring now to Figures 3 and 4, the closure flap 42 and its operation is shown in more detail. The door 6 is shown being fitted with a normal plate-type letterbox 52 having a flap 54. Figure 3 shows the closure flap 42 held in its open position by retainer means 56. When the retainer means 56 is released by release means, then the closure flap 42 moves to the position shown in Figure in which it seals the letterbox 2. This may be effected by spring biasing means.

When the closure flap 42 is in the position shown in Figure 4, it is locked shut by a lock 58. The lock 58 can only be unlocked from inside the letterbox 2 and this involves unlocking the lock 46 in the door 30.

Until this is done, the letterbox 2 is sealed, thereby starving any fire inside the letterbox 2 of oxygen, and thereby contaminating any liquid that might have been poured into the letterbox 2.

Figures 3 and 4 also show how the discharge nozzle 34 may be concealed in an ornamental head 58.

As can be seen from a comparison of Figures 3 and 4, the letterbox 2 is such that the bottom of the body 26 is formed as an integral container portion for containing the petrol 14 or other liquid that may be poured into the letterbox 2. Any petrol 14 or other liquid in the letterbox 2 after an attack can be drained out using a drain plug 62. This drain plug 62 is connected to a drain hole in the base of the body 26.

This hole is covered by a mesh cover 64 to prevent blockage.

The dye 24 is preferably a non-toxic removable dye, but nevertheless one which will mark the arsonist 12 for some time to make him identifiable. The dye 24 is contained in a reservoir 66 which can be filled up as necessary since it extends to one side of the body 26 as can best be appreciated from Figure 2. The reservoir 66 can be drained via a drain plug 68.

The pump 50 and the alarm 22 can be switched off by a control switch 70. A safety switch 72 is provided.

This safety switch 72 is attached to the door 6 as shown in Figure 2 and it will switch off the pump 50 if the pump 50 is operating when the door 6 is opened. This is to ensure that the pump 50 will not spray inside premises, for example a house, if the door is opened during an attack. As can be seen from Figure 1, the dye 24 is sprayed over the immediate area in front of the door 6 so that there is no possibility of the arsonist 12 or other attacker avoiding the spray of the dye 24.

The ornamental head 58 may be arranged to look like a door knocker or a decorative concealed fixture in order to disguise the fact that the dye 24 can be sprayed from the discharge nozzle 34.

The apparatus in the letterbox 2 can be powered by batteries 74 or, optionally, the apparatus can be powered by the mains via a transformer 76. If the apparatus is mains powered, then the batteries 74 are able to provide a back-up in the event of power failure.

If desired, the alarm 22 may be connected to the main alarm of the premises. This connection to the main alarm of the premises may be in addition to or as an alternative for the alarm 22 which is shown schematically in Figure 1 as sound. This sound comes from a speaker 78 as shown in Figures 3 and 4. The alarm 22 may also have a visual part such for example as a flashing light (not shown).

The retainer means 56 shown in Figures 3 and 4 may be an electrical and/or mechanical release catch. The release catch will release when it is activated by the trigger switch 48 or other sensor means.

Sensor means in the form of a heat sensing device 80 is employed to sense heat from any fire in the letterbox 2. As an alternative to using the heat sensing device 80, a smoke detector (not shown) may be used. When the heat sensing device 80 senses heat, or when the smoke detector detects smoke, then the retainer means 56 is released enabling the closure flap 42 to move from the open position shown in Figure 3 to the closed position shown in Figure 4. Any fire in the letterbox 2 is thus sealed off and starved of oxygen.

Additionally, if desired, a small fire extinguisher (not shown) may be employed inside the letterbox 2 to extinguish the fire. The heat sensing device 80 or the smoke detector may also activate other defences in the letterbox 2, for example the alarm 22 and the spraying of the dye 24.

The letterbox 2 may be made of a plastics material which is fire retardant. The material used for all or part of the letterbox 2 may be of a type which extinguishes fire by producing an appropriate liquid or gas, for example carbon dioxide, when the material starts to melt under the effects of a fire. Separate such material may also be placed inside the letterbox 2 for the purpose of extinguishing any fire in the letterbox 2.

Referring now to Figures 5 and 6, similar parts as in previous Figures have been given the same reference numerals for ease of comparison and understanding. In Figures 5 and 6, it will be seen that there are two discharge nozzles 34, with one being below the letterbox 2 and one being substantially above the letterbox 2.

Each discharge nozzle 34 is fed by tubing 82.

Figure 7 illustrates how there may be three discharge nozzles 34 lead by three different sets of tubing 82.

Figures 8 and 9 illustrates in detail the operation of the closure flap 42. Figures 8 and 9 also illustrate how the side plates 40 can each be provided with a central aperture 84 for exposing a screw 86 by means of which the letterbox 52 is secured in position on the door 6. The apertures 84 in the side plates 40 thus enable the letterbox 52 to be removed from the front of the door 6 without the need to remove the letterbox 2 from the rear of the door 6.

Figure 10 shows a post box in the form of a postal authority pillar box 88 and similar parts as in previous Figures have been given the same reference numerals for ease of comparison and understanding. In Figure 10, the pillar box 88 has a door 30 in a lower part of the body 26. Much of the detector apparatus and alarm apparatus is housed in a domed part 90 of the pillar box 88. The closure flap 42 closes a slot 28 for postal items as shown.

Instead of being powered by one or more batteries 74, the power for the pillar box 88 could be provided by solar panels, wind power or any other suitable and appropriate power source. If desired, with the pillar box 88, the slot 28 could be opened up after a predetermined period of time in order to allow the public to use the pillar box 88 again.

It is to be appreciated that the embodiments of the invention described above have been given by way of example only and that modifications may be effected.

Thus, for example, some of the illustrated components may be omitted, or they may be used in other combinations. The body 26 of the post box may be of any suitable and appropriate shape depending upon the different types of post box. Where the post box is in the form of a letterbox for use inside, then its design will normally be compatible with the opening of a door against a wall to allow the door to open as far as possible with minimum restriction caused by the letterbox. Various types of sensor means may be employed such for example as trigger switches, float switches, pressure switches and mercury switches.

Claims

1. A post box comprising a body, a slot in the body for enabling postal items to be inserted into the body, a door for enabling postal items which have been inserted into the body to be retrieved, at least one defence mechanism for protecting the post box consequent upon the post box being subject to an attack, and at least one sensor means for sensing the attack and causing the defence mechanism to operate.

2. A post box according to claim 1 and comprising a container portion for retaining liquids poured into the post box.

3. A post box according to claim 2 in which the container portion is formed as an integral part of the body.

4. A post box according to claim 2 in which the container portion is a separately formed tray which is inserted into the body.

5. A post box according to any one of the preceding claims in which the sensor means comprises a heat sensor which is such that it causes the defence mechanism to operate when the heat sensor senses heat.

6. A post box according to any one of the preceding claims in which the sensor means comprises a smoke detector which is such that it causes the defence mechanism to operate when the smoke detector detects smoke.

7. A post box according to any one of the preceding claims in which the sensor means comprises a liquid detector which is such that it causes the defence mechanism to operate when the liquid detector detects a liquid.

8. A post box according to claim 7 in which the liquid detector operates by touch so that it operates when it is touched by the liquid.

9. A post box according to claim 7 in which the liquid detector operates by sensing the smell of the liquid.

10. A post box according to any one of the preceding claims in which the defence mechanism comprises closure means for closing the slot in the body.

11. A post box according to claim 10 in which the closure means comprises a closure flap.

12. A post box according to claim 11 in which the closure flap is spring biased to a closed position, and in which the closure means includes retainer means for retaining the closure flap in an open position, and release means for releasing the retainer means consequent upon the sensor means sensing the attack.

13. A post box according to any one of claims 10-12 and including lock means for keeping the closure means in the closed position during an attack.

14. A post box according to any one of the preceding claims in which the defence mechanism comprises fire extinguisher means for releasing a substance for putting out a fire in the post box.

15. A post box according to claim 14 in which the fire extinguisher means is able to release a powder substance or a foam substance for putting out the fire in the post box.

16. A post box according to any one of the preceding claims in which the defence mechanism comprises alarm means for directing attention to the attack on the post box.

17. A post box according to claim 16 in which the alarm means is an audio and/or visual alarm means.

18. A post box according to claim 16 or claim 17 in which the alarm means is a separate alarm means for the post box.

19. A post box according to claim 16 or claim 17 in which the post box is for use in premises, and in which the alarm means is the alarm means of the premises, the post box being provided with connection means for connecting the post box to the alarm means of the premises.

20. A post box according to any one of the preceding claims in which the defence mechanism comprises a dye discharge system.

21. A post box according to claim 20 in which the dye discharge system comprises a pressurised dye cannister which contains the dye.

22. A post box according to claim 20 in which the dye discharge system comprises a pump for discharging the dye.

23. A post box according to claim 22 in which the pump is such that it is also able to be used for discharging a fire-extinguishing substance inside the post box to put out any fire in the post box.

24. A post box according to any one of the preceding claims in which the post box is a letterbox, and in which the letterbox is made of a fire resistant plastics material.

25. A post box according to any one of the preceding claims in which the door is a hinged door.

26. A post box substantially as herein described with reference to the accompanying drawings.