There is a special type of protected insertion letterbox known from UK Patent GB 2345728 that provides protection against objects, including liquid and gas, penetrating into the premises through the letterbox, protection against using the letterbox as a container for holding liquid and gas, protection against draughts and protection against mail theft from the letterbox.

The disadvantage of the known protected insertion letterbox is that when it is installed onto the door (wall) mail channel internal aperture it is not convenient for the mail carrier to insert the items of mail behind the external perforated access flap. This action requires from the mail carrier pushing his fingers deep inside the mail channel, which is uncomfortable or even impossible, were the mail channel is narrow. It is even more uncomfortable if there is a letter plate means with the inbuilt delivery flap means installed onto the delivery aperture of the mail channel because the delivery flap means creates an additional obstacle for this action.

As a result, the mail carrier may leave the items of mail inserted into a mail channel only behind the delivery flap means of the letter plate means but not completely inserted behind the external perforated access flap, which makes them easily accessible for mail theft.

Since the letter plate means with the inbuilt delivery flap means is a developed and universally used item of door furniture, this disadvantage significantly undermines the possibility of using the known protected insertion letterbox inside the properties on the door (wall) internal surface in conjunction with the letter plate means fixed on the external surface.

Another disadvantage of the known protected insertion letterbox is that it has limited facilities for fixing without the undesired intrusion into the structure of the door (wall). Its fixing to the structure with the screws means may cause difficulty in fixing, damage to the structure and to the appearance. It is especially difficult and expensive to have the known protected insertion letterbox fixed to the hollow PVC and metal doors.

To avoid this problem in some cases it is possible to fix the known protected insertion letterbox to a letter plate means using letter plate fixing means. However, letter plate fixing means, usually threaded rods or screws, have diverse specifications. Furthermore, their length is normally cut to size during installation. For that reasons, fixing of the known protected insertion letterbox to the earlier, often many years earlier, installed letter plate means requires finding of a new replacement pair of the fixing means with the same specifications as the old ones and long enough, which can be problematic.

Further disadvantage of the known protected insertion letterbox is that the introduced items of mail have to be considerably bent and its ability to take in items of mail that are rigid or long for example, books and newspapers, is limited.

One more disadvantage of the known protected insertion letterbox is that it can create too much of an obstruction to the door opening, especially, when the entrance passageway is narrow and the letterbox is mounted on a surface of the door that opens inside the property.

The object of the present invention is therefore to provide a security letterbox assembly suitable for fixing on a door, wall, freestanding support stand, etc. , with protection against objects, including liquid and gas, penetrating into the premises through the letterbox, protection against using the letterbox as a container for holding liquid and gas, protection against draughts, protection against mail theft from the letterbox, suitable for installation onto a mail channel internal aperture in conjunction with a diversely sized letter plate means, adapted for fixing to diversely sized letter plate means by utilizing their diverse fixing means or for fixing to a structure and with the reduced obstruction to the door opening when mounted on a door surface.

According to the present invention there is provided a security letterbox assembly comprising a watertight mail collection container means, a letter plate means with a delivery flap means and a mail protection means with a mail insertion slot arranged in a lower part of a front wall of the watertight mail collection container means, with a watertight means securing a hermetic seal between the mail insertion slot and a mail channel, with a bottom wall of the watertight mail collection container means being provided in the form of an acclivity, rising from the mail insertion slot lower edge, a mail detention means, fixed inside the watertight mail collection container means, adapted to pass liquid and gas, with a watertight lockable door means provided in the watertight mail collection container means for access to the stored mail, with a fixing means provided in the watertight mail collection container means, with the letter plate means positioned in the mail channel delivery aperture so that in an open position the delivery flap means allows unobstructed introduction of mail items, an adjustable security setting means, provided in the vicinity of the delivery flap means and the mail insertion slot, the mail protection means adjustably provided in the vicinity of the mail insertion slot and influenced by the movement of the delivery flap means.

The specific embodiments of the invention will now be described by way of examples with reference to the accompanying drawing in which:- Figure 1 shows the side view in section of the proposed invention with the first embodiment of the watertight mail collection container means in disassembly of some of its parts. Figure 2 shows the side view in section of the proposed invention with the first embodiment of the watertight mail collection container means fixed onto the internal aperture of the mail channel.

Figure 3 shows the internal surface of the front wall of the first embodiment of the watertight mail collection container means. Figure 4 shows the bottom view in section of the watertight mail collection container means. Figure 5 shows the side view in section of the proposed invention with the second embodiment of the watertight mail collection container means in disassembly of some of its parts. Figure 6 shows the side view in section of the proposed invention with the second embodiment of the watertight mail collection container means fixed onto the internal aperture of the mail channel. Figure 7 shows the side view in section of the proposed invention with the third embodiment of the watertight mail collection container means fixed onto the internal aperture of the mail channel.

Referring to the drawings the security letterbox assembly generally comprises a watertight mail collection container means 1 fixed onto the internal aperture of a mail channel 2 arranged in a structure 3, a letter plate means 4 with the inbuilt delivery flap means 5 fixed onto external aperture of the mail channel 2 and a mail protection means 6 provided in the vicinity of a mail insertion slot 7 and fixed to the watertight mail collection container means 1, to the inbuilt delivery flap means 5, or in the mail channel 2. The mail channel 2 can be arranged in the structure of a door, wall, etc.

The inbuilt delivery flap means 5 in its open position allows the unobstructed introduction of the items of mail through the mail insertion slot 7. This is achieved, for example, but not exclusively, by fixing the letter plate means 4 in the position, where the axle 8 of the inbuilt delivery flap means 5 is near the lower edge of the delivery aperture of the mail channel 2, so that applying pressure to its upper edge can open the inbuilt delivery flap means 5. A spring means (not shown) fixed on the axle 8 keeps the inbuilt delivery flap means 5 in a closed position for the items of mail.

A watertight means 9, for example, a gasket means is fixed around the mail insertion slot 7 in order to secure a hermetical seal around its perimeter when the watertight mail collection container 1 is mounted onto a mail channel 2 internal aperture.

The watertight mail collection container means 1 bottom wall 10 is provided in a form of an acclivity rising from the mail insertion slot 7 lower edge so that due to the gravity an unobstructed passage of substances, particularly, liquid and gas is allowed out of the watertight mail collection container means 1 through the mail insertion slot 7.

A mail detention means, fixed inside the watertight mail collection container means 1 and adapted to pass liquid and gas, includes, for example, but not exclusively, a flap means 11 with a jagged edge which is fixed on a spring loaded hinge means 12 to the front wall 13 and a mail retention means 14 with a jagged edge which is fixed inside the watertight mail collection container means 1. The spring means force pushes the flap means 11 jagged edge towards the jagged edge of the mail retention means 14 and towards a lockable door means 15.

The lockable watertight door means 15 allows access to the stored items of mail through the access aperture 16 arranged in the watertight mail collection container means 1.

The mail protection means 6 is fixed near the mail insertion slot 7 and allows adjustment of its position in the insertion slot 7. It can be fixed to the watertight mail collection container means 1, in the mail channel 2 or to the letter plate means 4. It is adapted to be influenced by the movement of the inbuilt delivery flap means 5 into an action the purpose of which is protection of the inserted items of mail against attempted access to them through the mail insertion slot 7.

This can be achieved, for example, but not exclusively, by pushing the inserted items of mail deeper inside the watertight mail collection container 1, by creating obstruction for access to them through the mail channel 2, by using both of these methods or by using other methods and combinations of methods.

Sidewalls 17 of the watertight mail collection container 1, or at least one of them, are provided inclined inside the watertight mail collection container 1 towards the front wall 13 for allowing less obstruction to the door opening when the watertight mail collection container means 1 is mounted on a door since the rear wall 18 edge is positioned farther away from the door pivot.

The watertight mail collection container means 1 is provided with fixing means allowing fixing it to a variety of diverse sized letter plate means 4 or to the structure 3 and with a security setting means allowing setting of the maximum extent of the inbuilt delivery flap means 5 opening.

As a first embodiment of the security letterbox assembly, the fixing means and a security setting means are provided in a form of two corner-shaped clamping brackets 19 with a side flange 20 where several threaded holes 21 are provided to accommodate a screw means 22. A through attachment hole 23 is provided in each of the corner-shaped clamping brackets 19.

The screw means 22 and the threaded holes 21 represent the security setting means. The screw means 22 can be positioned in any one of the provided threaded holes 21 during the security letterbox assembly installation so that the maximum extent of the inbuilt delivery flap 5 opening can be set and adjusted since it is limited by the position of the screw means 22. The level of the security is increased when the maximum extent of the inbuilt delivery flap 5 opening is reduced.

The letter plate means 4 fixing screws means 24 free ends are inserted through the attachment holes 23 which are accessed through the mail insertion slot 7. Nut means 25 is tightened behind a washer means (not shown) on the end of the fixing screws means 24 and this allows fixing the watertight mail collection container means 1 to the letter plate means 4. The provided corner- shaped clamping brackets 19 allow the adjustment of their position so that it can match a diverse position of the letter plate fixing means 4 housings 27.

Where the letter plate means 4 was installed earlier, its fixing screws means 24 were usually shortened during the installation. The shortened fixing screws means 24 may not be long enough to allow fixing the watertight mail collection container means 1 to the letter plate means 4.

In order to utilize the shortened fixing screws means 24, the collar bushes means 26 are provided in the attachment holes 23, with their bodies made long enough for fixing the watertight mail collection container means 1 to the letter plate means 4 using its shortened fixing screws means.

The collar diameter is provided larger than the attachment hole 23 diameter, so that the collar stops the collar bushes means 26 from falling through the attachment holes 23. The collar bushes means 26 are provided with through bolt holes 28 in them for inserting the fixing screws means 24. The internal diameter of the through bolt hole 28 on the collar end is arranged larger than on the other end for accommodating the nut means 25.

The watertight mail collection container means 1 front wall 13 is extended below the bottom wall 10 with the area of the extension overlaying the mail channel 2 internal aperture and is set against the structure 3 below the internal aperture of the mail channel 2.

The access aperture 16 can be arranged for example, but not exclusively, in the watertight mail collection container means 1 rear wall 18.

The mail protection means is provided for example, but not exclusively, in the form of a hinge means assembly 6 created by three plates joined together by two spring-loaded axles and adjustably fixed to the support comer-shaped rail 29 positioned near the mail insertion slot 7 lower edge. The spring means act to drive the hinge means assembly 6 into a flat position.

The top wall 30 is provided inclined downwards from the front wall 13 top edge towards the rear wall 18 top edge. As a result, the long sized items of mail inserted into the watertight mail collection container means 1 have to bend when they reach the top wall 30 and follow its direction. This allows storing of the long sized items of mail without increasing the watertight mail collection container means 1 height dimension.

As a second embodiment of the security letterbox assembly the fixing means, allowing fixing the watertight mail collection container means 1 to the letter plate means 4 or to the structure 3, is provided in a form of two attachment slots 31, arranged in the front wall 13 extension below the insertion slot 7 lower edge and two clamping brackets 32, having a through fixing hole 33.

The clamping brackets 32 are placed over the front wall 13 extension, so that their fixing holes 33 are positioned over the attachment slots 31. The clamping brackets 32 allow adjusting their position so that the fixing holes 33 position can match the diverse positions of the letter plate means 4 housings 27. They also serve as a means of support to the bottom wall 10.

Using the letter plate 4 fixing screws means 24, the watertight mail collection container means 1 can be fixed to the letter plate means 4 similarly as in the first embodiment of the watertight mail collection container means 1 and the collar bushes means 26 can be used similarly in order to allow utilizing of the shortened fixing screws means 24 of the letter plate means 4.

The front wall 13 is extended below the insertion slot 7 lower edge with the area of the extension overlaying the mail channel 2 internal aperture and is set against the structure 3.

The mail protection means is provided for example, but not exclusively, in a form of a hinge means assembly 6 created by three plates joined together by two axles one of which is spring- loaded and a screen means 34 fixed to the front wall 13 internal surface above the mail insertion slot 7 top edge. The hinge means assembly 6 is adjustably fixed to the front wall 13.

The hinge means 6 top part is fixed on an axle without a spring means. Its end is set on the bottom wall 10 surface and is adapted to move along the bottom wall 10 when the inbuilt delivery flap means 5 is pushed into the open position for the introduction of the items of mail.

The hinge means 6 position in the mail insertion slot 7 is made adjustable by providing a few fixing holes on it (not shown). This allows the hinge means 6 to serve also as the adjustable security setting means since the maximum extent of the inbuilt delivery flap 5 opening is influenced by the position of the hinge means 6.

The screen means 34 also provides protection against attempts to access the flap means 11 through the insertion slot 7.

As a third embodiment of the security letterbox assembly, the fixing means allowing fixing the watertight mail collection container means 1 to the letter plate means 4 or to the structure 3 is provided in a form of a spring-loaded hinge means 35 attached to the watertight mail collection container means 1 and to a mounting bracket means 36 which is provided with two attachment slots suitable to accommodate the collar bush means 26.

The front wall 13 is, for example, but not necessarily, extended below the insertion slot 7 lower edge with the area of the extension used to fix the watertight mail collection container means 1 to the spring-loaded hinge means 35.

The mail protection means 6 is provided for example, but not necessarily, in a form of a hinge means assembly created by three plates joined together by two spring-loaded hinges and fixed to the mounting bracket means 36.

The mail protection means 6 also represent the security setting means. Its adjustable position allows setting of the inbuilt delivery flap means 5 maximum opening.

The letter plate 4 fixing screws means 24 free ends are inserted through the attachment slots provided in the mounting bracket means 36, which are accessed through the mail insertion slot 7. The nut means is tightened on the end of the fixing screws means 24 and this allows fixing the watertight mail collection container 1 to the letter plate means 4 using the mounting bracket means 36.

A watertight means 37, for example, a gasket means is fixed on the mounting bracket means 36 surface adjacent to the structure 3 surface so that it secures the water tightness between the mounting bracket means 36 and the mail channel 2 internal aperture. Together with the watertight means 9 it secures a hermetic seal between the mail insertion slot 7 and the mail channel 2.

In order to be able to utilize the shortened fixing screws means 24 of the letter plate means 4, the collar bushes means 26 are provided in the attachment slots like in the first and second embodiments of the watertight mail collection container 1.

The spring-loaded hinge means 35 allows a limited turning displacement of the watertight mail collection container means 1 about its lower edge initiated by the introduction of the rigid items of mail through its mail insertion slot 7 and to a restoration of its original position.

Means of protection of the mail channel 2 and of the watertight means 9 and 37 against damaging actions or events such as fire, vandalism, forced entry, etc. , can be provided in the mail channel 2 and in the watertight means 9 and 37 (not shown). The protection means can be made in the form of a metal sleeve fixed to the bracket means 36 and inserted into the mail channel 2 and through the watertight means 9 and 37.

Additional attachment means can be provided in the watertight mail collection container 1 or in the mounting bracket 36 allowing fixing them to the mail channel 2 or to the structure 3. Such additional attachment means for example, but not exclusively, can be provided in the form of an attachment holes (not shown) arranged in the front wall 13 or in the mounting bracket 36 for allowing fixing the watertight mail collection container 1 with the help of the screws or bolts to the means of protection against damaging actions or events such as fire, etc. , installed in the mail channel 2.

While the inbuilt delivery flap means 5 is in its closed position, the mail protection means 6 is in a folded position inside the mail channel 2. When the delivery flap means 5 is pushed into the open position to allow the insertion of the items of mail, it pushes the mail protection means 6.

As in the first embodiment of the security letterbox assembly, the mail protection means 6 top part enters into the mail insertion slot 7 and straightens up inside due to the pressure from its inbuilt spring means. As a result, it becomes like an extension of the inbuilt delivery flap means 5, which is projected deeper inside the mail insertion slot 7.

The inbuilt delivery flap means 5 and the straightened up mail protection means 6 serve as a rising slope that directs the inserted items of mail to enter the watertight mail collection container means 1 at an angle to its rear wall 18. It also pushes the earlier inserted items of mail deeper into the watertight mail collection container means 1 and obstructs access to them through the mail channel 2.

As in the second embodiment of the security letterbox assembly, the mail protection means 6 free part moves up the sloping bottom wall 10 and pushes the earlier inserted items of mail deeper into the watertight mail collection container means 1.

It is the duty of the mail carrier to push the items of mail behind the inbuilt delivery flap means 5 and to make sure that it is closed. When the inbuilt delivery flap means 5 is opened again, the inserted items of mail are automatically pushed deeper inside the watertight mail collection container means 1 by the opened up mail protection means 6 and become inaccessible for the mail theft.

Directed by the rising slope, the inserted items of mail hit the rear wall 18 of the watertight mail collection container means 1 at an angle. This forces the inserted items of mail to bend up and slide up along the rear wall 18.

On the way, the items of mail move the flap means 11 from the position, in which it is pressed by a spring means against the rear wall 18 and the door means 15 internal surfaces, into the position, where it is at a distance from the surfaces. This allows the items of mail to move between the jags of the flap means 11 and the mail retention means 14.

Depending on the strength of the original insertion push and their size the flexible items of mail might move up behind the flap means 11 and be placed into the middle and upper parts of the watertight mail collection container means 1, where there is arranged enough free space for them. Alternatively, they might be clenched between the jags and pressed against the door means 15 internal surface or fall on the bottom wall 10.

In any case, the items of mail are detained and protected from the attempts to have them removed from the watertight mail collection container means 1 through the mail channel 2.

As in the third embodiment of the security letterbox assembly, the flexible items of mail move into the watertight mail collection container means 1 and are detained there in the same way as in the first and second embodiments of the security letterbox assembly.

However, the items of mail with limited flexibility or rigid would make a stronger pressure on the watertight mail collection container means 1 wall. This pressure can cause the temporary turning displacement of the watertight mail collection container means 1 about the spring-loaded hinge means 35. As a result, the mail insertion slot 7 upper edge moves away from the upper edge of the mail channel 2 internal aperture.

The increased gap in the mail insertion slot 7 upper edge allows the rigid item of mail to be introduced inside the watertight mail collection container means 1 without being bent or after being bent only slightly. This result is achieved without loosing the water tightness between the mail channel 2 internal aperture and the mail insertion slot 7 due to the provision of the flexible watertight means 9.

The spring means in the spring-loaded hinge means 35 gets stretched during the turning displacement and once there is no more external pressure, it straightens back bringing back to its original position the watertight mail collection container means 1 with the mail stored inside it.

A limiter (not shown) provided, for example, but not exclusively, in the spring-loaded hinge means 35, limits the turning displacement amplitude. The catchment means (not shown) provided, for example, but not exclusively, in the spring-loaded hinge means 35, allows blocking the turning displacement function of the watertight mail collection container means 1.

If it is attempted to pour or to pump liquid through the mail channel 2, than due to the gravity, any introduced liquid will flow down and pass out of the watertight mail collection container means 1 though the mail insertion slot 7 and out through the letter plate means 4, which is preferably provided non-watertight.

The optimum dimensional relationships for the parts of the invention as described and illustrated in the drawings are deemed obvious and apparent to one skilled in the art and are intended to be encompassed by the present invention.