GB2129868A

GB2129868A - Fire proof letter box

Info

Publication number: GB2129868A
Application number: GB08231747A
Authority: GB
Inventors: Martin John Cooke
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-11-06
Filing date: 1982-11-06
Publication date: 1984-05-23

Abstract

The box comprises a container 1 of fire resistant material which in use is secured to a door. The container includes a first opening closeable by a cover 2, a second opening 4 to cooperate with a letter flap of said door, spring means to urge a flap 6, when released, to close the second opening and a heat responsive strip 9 retaining the flap 6 in a raised position. If burning material is inserted into the box, the strip 9 gives way releasing the flap 6 which is urged to close the opening 4 and thus seal the container. <IMAGE>

Description

SPECIFICATION Fire proof letter box This invention relates to a letter box which is resistant to attempts by vandals to insert burning or inflammable material through the letter flap in a door. Vandalism of this nature is not only dangerous and expensive to the victim who may have to redecorate the interior of his home, but is also extremely distressing since victims are often subject to repeated attacks.

According to the present invention a letter box comprises a container constructed from fire resistant material and adapted to be secured in use to a door, including a first opening closeable by a cover, a second opening arranged in use to cooperate with a letter flap of said door, means adapted upon actuation to urge a member to close the second opening and further means responsive to heat to cause said actuation. The cover is normally arranged to close the first opening, the opening being used to remove letters from the box.

In use of the letter box, if burning material is inserted into the box through the letter flap of the door or if incendiary material is so inserted and then ignited, the heat generated in the container will actuate the heat responsive means and cause the member to close the second opening. The container is thereby sealed, cutting off the air supply to the fire and preventing fire damage to the door and surroundings.

The means adapted to urge closure of the second opening may comprise one or more springs or a gravity operated arrangement such as a weight attached to the member.

The heat responsive means may comprise any device arranged to restrain closure of the member until the means is heated.

A preferred heat responsive means comprises an article composed of an easily meltable or combustible substance, arranged to obstruct movement of the member to close the opening. A particularly preferred article is an elastic or rubber band. This may be stretched across the container in the path of the member.

The member is preferably disposed at the top of the interior of the container when the second opening is open, so that heat and flames generated within the container bear against the heat responsive means.

The member may be provided with a catch which engages the container when the opening is closed. The catch may serve to lock the second opening from the interior, preventing further inflammable or burning material from being inserted through the letter flap.

The letter box may be connected to an alarm system such as a remote electric bell.

The container is preferably water-tight so that liquids such as petrol or paraffin are retained therein.

The letter box is preferably composed of metal such as steel. Closure of the second opening may be advantageously noisy, serving to alarm a would-be vandal.

The invention is further described by way of example with reference to Figures 1 to 6 of the accompanying drawings, of which: Figure 1 is a partially cut away perspective view of a letter box in accordance with the invention; Figure 2 is a front elevation of the box shown in Figure 1; Figure 3 is a section on A-A of Figure 2; Figure 4 is an end elevation of the letter box; Figure 5 is a rear elevation of the letter box; and Figure 6 is a section on B-B of Figure 4.

The letter box shown in the drawings comprises a container 1 composed of welded steel sheet and finished with fire resistance paint. The seams of the container are water-tight. The container includes two openings, the first of which is closeable by a cover 2 secured to a hinge 8. A hasp - 3 is provided so that the cover may be locked. The second opening 4 is dimensioned so that a letter flap of a door may open through it so that mail may be passed into the container. Two oval eyes 5 are provided so that the letter box may be removably secured to a door.

A flap 6 is hinged 13 above the opening 4 and a spring 7 is arranged to urge closure of the flap. A rubber band 9 extends between a pair of grooves 10 located on the upper portion of the container.

The flap 6 is held in use in an open position by the band 9. A catch 11 secured to the flap 6 cooperates with a latch 12 to lock the flap 6 when the opening is closed. The flap 6 is arranged with sufficient clearance from the walls of the container to ensure that there can be no obstruction by the burned elastic band. A fireproof gasket (not shown) may be provided between the container and the door.

In use of the letter box, a fire in the container will cause the rubber band 9 to burn and snap, releasing the flap 6. The flap will then be urged to close the opening 4, extinguishing the fire and preventing insertion of further inflammable material. The sealed container may be removed from the door by virtue of the oval eyes 5, for safe disposai of the contents.

1. A letter box comprising a container constructed from fire resistant material and adapted to be secured in use to a door, including a first opening closeable by a cover, a second opening arranged in use to cooperate with a letter flap of said door, means adapted upon actuation to urge a member to close the second opening and further means responsive to heat to cause said actuation.

2. A letter box as claimed in claim 1, wherein the said means adapted to urge a member to close the second opening comprises one or more springs or a gravity operated arrangement.

3. A letter box as claimed in claim 1 or 2, wherein the heat responsive means comprises an article composed of an easily meltable or combustible substance arranged to obstruct

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fire proof letter box This invention relates to a letter box which is resistant to attempts by vandals to insert burning or inflammable material through the letter flap in a door. Vandalism of this nature is not only dangerous and expensive to the victim who may have to redecorate the interior of his home, but is also extremely distressing since victims are often subject to repeated attacks. According to the present invention a letter box comprises a container constructed from fire resistant material and adapted to be secured in use to a door, including a first opening closeable by a cover, a second opening arranged in use to cooperate with a letter flap of said door, means adapted upon actuation to urge a member to close the second opening and further means responsive to heat to cause said actuation. The cover is normally arranged to close the first opening, the opening being used to remove letters from the box. In use of the letter box, if burning material is inserted into the box through the letter flap of the door or if incendiary material is so inserted and then ignited, the heat generated in the container will actuate the heat responsive means and cause the member to close the second opening. The container is thereby sealed, cutting off the air supply to the fire and preventing fire damage to the door and surroundings. The means adapted to urge closure of the second opening may comprise one or more springs or a gravity operated arrangement such as a weight attached to the member. The heat responsive means may comprise any device arranged to restrain closure of the member until the means is heated. A preferred heat responsive means comprises an article composed of an easily meltable or combustible substance, arranged to obstruct movement of the member to close the opening. A particularly preferred article is an elastic or rubber band. This may be stretched across the container in the path of the member. The member is preferably disposed at the top of the interior of the container when the second opening is open, so that heat and flames generated within the container bear against the heat responsive means. The member may be provided with a catch which engages the container when the opening is closed. The catch may serve to lock the second opening from the interior, preventing further inflammable or burning material from being inserted through the letter flap. The letter box may be connected to an alarm system such as a remote electric bell. The container is preferably water-tight so that liquids such as petrol or paraffin are retained therein. The letter box is preferably composed of metal such as steel. Closure of the second opening may be advantageously noisy, serving to alarm a would-be vandal. The invention is further described by way of example with reference to Figures 1 to 6 of the accompanying drawings, of which: Figure 1 is a partially cut away perspective view of a letter box in accordance with the invention; Figure 2 is a front elevation of the box shown in Figure 1; Figure 3 is a section on A-A of Figure 2; Figure 4 is an end elevation of the letter box; Figure 5 is a rear elevation of the letter box; and Figure 6 is a section on B-B of Figure 4. The letter box shown in the drawings comprises a container 1 composed of welded steel sheet and finished with fire resistance paint. The seams of the container are water-tight. The container includes two openings, the first of which is closeable by a cover 2 secured to a hinge 8. A hasp - 3 is provided so that the cover may be locked. The second opening 4 is dimensioned so that a letter flap of a door may open through it so that mail may be passed into the container. Two oval eyes 5 are provided so that the letter box may be removably secured to a door. A flap 6 is hinged 13 above the opening 4 and a spring 7 is arranged to urge closure of the flap. A rubber band 9 extends between a pair of grooves 10 located on the upper portion of the container. The flap 6 is held in use in an open position by the band 9. A catch 11 secured to the flap 6 cooperates with a latch 12 to lock the flap 6 when the opening is closed. The flap 6 is arranged with sufficient clearance from the walls of the container to ensure that there can be no obstruction by the burned elastic band. A fireproof gasket (not shown) may be provided between the container and the door. In use of the letter box, a fire in the container will cause the rubber band 9 to burn and snap, releasing the flap 6. The flap will then be urged to close the opening 4, extinguishing the fire and preventing insertion of further inflammable material. The sealed container may be removed from the door by virtue of the oval eyes 5, for safe disposai of the contents. CLAIMS

3. A letter box as claimed in claim 1 or 2, wherein the heat responsive means comprises an article composed of an easily meltable or combustible substance arranged to obstruct movement of the member to close the opening.

4. A letter box as claimed in claim 3, wherein the heat responsive means comprises an elastic or rubber band.

5. A letter box as claimed in claim 3 or 4, wherein the heat responsive means is disposed at the top of the interior of the container.

6. A letter box as claimed in any preceding claim, wherein the member comprises a catch which engages the container when the opening is closed.

7. A letter box as claimed in any preceding claim, wherein the container is water-tight.

8. A letter box substantially as hereinbefore described with reference to the accompanying drawings.