Bloomsbury Rear Retrieval Letterbox

 A standard 9" wall

 Fixed into metal railings

Fitted into a wooden fence

These are the overall width and height dimensions of the Bloomsbury mailbox, also shown is the distance between the front and rear castings of the postbox.

• A = 425mm, this is the dimension of the absolute height of the front and rear castings of the Bloomsbury post box. This is bigger than the sleeve which fits between the 2 castings. the dimensions of the inner sleeve are shown below.
• B = 295mm, this is the size of the overall width of the LS05 mailbox, as with the height dimension above, the width of the front and rear castings is greater than the width of the inner sleeve which is shown below.
• C = 220mm, this is the distance between the front and rear castings of the postbox when fitted with a standard size sleeve. This is 5mm greater than a typical 9 inch wall which the standard sleeve is made for. The reason for this is to allow for building tolerances. All of the Lettasafe mailboxes are fitted with rubber seals along the connecting edges of the sleeve and the castings. When the letterbox is fitted together a watertight seal is formed. To guarantee that the letterbox is watertight the front and rear castings must clamp tightly with the central sleeve. Invariably brick walls and piers have some degree of tolerance and this is the reason we add an extra 5mm to the central sleeve depth.

 Shown below are the dimensions of a standard size sleeve designed for a 9 inch wall.

• A = 402mm, the distance between the bottom face of the sleeve and the top of the apex, the overall height of the letterbox sleeve is taller as the sides extend below the bottom by 13mm making a total depth of 425mm. These extensions to the sides are generally bedded into the mortar when being built into a brick wall.
• B = 383mm, the distance between the bottom of the sleeve to the top of the side before the apex begins. The apex of the sleeve rises 20mm from the side to the peak in the centre.
• C = 397mm, the dimension of the side of the sleeve from the very bottom to the lower point of the top apex.
• D = 230mm, the depth of the standard size sleeve. We can manufacture sleeves up to 900mm deep. When the letterbox is being fitted into a brick wall, this dimension is always 15mm bigger than the depth of the wall. The reason for this is that both of the front and rear castings have a 5mm groove for the sleeve to slot into and 5mm is to allow for building tolerances, making 15mm in all.
• E = 275mm, this is the width of the sleeve.
• F = 13mm, this dimension is the distance between the bottom of the sides and the floor of the mailbox sleeve.

 Side dimensions of the standard size LS05 postbox.

• A = 293mm, This is the overall distance from the very front of the post flap to the hinge casting on the rear retrieval door. This is an important dimension when the letterbox is being fitted into electric sliding gates. The overall depth is the case size + 63mm.
• B = 220, The distance between the faces of the front and rear postbox castings. This dimension is always 5mm larger than the depth of the wall and is to allow for building tolerances.

 These are the sizes of the postbox flap entrance.

• A = 230mm, this is the overall width of the post flap entrance, the casting of the postbox flap has 2 small inserts at the bottom to house rubber stops. These are used to protect the letterbox post flap from damage when allowed to slam shut. The sizes of these inserts are about 10mm square
• B = 57mm, this is the height of the letter flap opening.

The size of the postbox opening is quite adequate for A4 or larger pacels and packages. A telephone directory size parcel will easily fit through the letterbox opening.

Below are the dimensions of the rear access door of the LS05 Bloomsbury rear retrieval postbox.

• A = 180mm, this is the width of the rear retrieval doorway
• B = 185mm, this is the height of the rear door entrance

The diagonal distance of the letterbox opening is 257mm, easily big enough to remove A4 or large packages. A telephone directory sized package can be removed from the letterbox without needing to be bent in any way.

The drawing to the left shows the ideal size of the aperture to be formed in the wall.

The sizes allow approximately 3mm clearance all round.

It should be noted that top of the case slopes down both ways from the centre when viewed from the front.

This illustration shows the standard size Lettasafe suitable for a 9" (215mm) thick wall.

We can supply sheet metal cases to suit walls / piers up to 900mm thick to special order.

It is important, on the front face of the wall, to position the case so that a minimum of 5mm protrudes from the wall as the castings are recessed on their rear face.

The rear part of the case should also protrude to a minimum of 5mm. It can, on thinner walls protrude for a greater amount. See drawing below.

Ensure that the Silicon rubber seal channel is positioned over the edges of the sheet steel case prior to re-fitting the castings.