An Improved Letter Box.
Year: 1892

page_text: Date of Application, 5th Jan., 1892
Complete Specification Left, 27th Sept.. 1892-Accepted, 29th Oct., 1892
PROVISIONAL SPECIFICATION.
An Improved Letter Box.
I, HENRY COLEMAN of 12 Jesse Terrace, Reading, in the County of Berks.,
Ironmonger, do hereby declare the nature of this invention to be as follows:-
My improved letter box is designed to enable the letters received through an
ordinary letter plate on a street door to be removed and conveyed to the owner by
a messenger without the messenger having access to the letters.
To effect this I construct a frame of iron or other material which is attached to
the back of the street door so as to enclose the aperture of the letter plate. I
attach the box to this frame by means of two vertical studs or pins in the lower end
of the frame, which engage with holes in the lower end of the box. The upper end
of the box is attached removably to the frame by means of projecting flanges one
on each side under which a sliding piece of wood or metal forming a false back to
the box is arranged to pass and when drawn up to its full height is secured by a
spring lock the key of which can be held by the messenger.
When thus secured an orifice in the false back is brought immediately opposite
to the aperture in the street door and the crifice in the letter box so that letters can
be passed into the box.
For greater security the door which the owner unlocks to get his letters is not
as usual on the front or outside of the box, but is placed on the side immediately
against the street door, and the screws which fix the frame on the street door are
covered by the box when in place, so that it is impossible to unscrew the frame and
remove the box that way.
To remove the box the messenger unlocks the lock on the top of the false
back when he must push down the false back until it clears the detaining
flanges on the frame, whereby the aperture of the box is closed by the false back
covering it.
At the same time the false back is automatically secured at its lower end inside
the box by a spring bolt on the bottom of the box engaging with a special catch on
the false back or in any other suitable way. The box can now be removed intact
from the frame and conveyed to the owner.
The owner opens a separate lock on the box door of which he keeps the key.
The act of opening the door releases the bolt which holds the false back. This
is done by drawing back the catch which is on the false back at the back of the
door. When the door is again closed a spring shield or protecting plate is auto-
matically interposed between the bolt and the catch, so as to prevent their again
engaging together. This is necessary in order to allow the box to be refixed on the
street door by drawing up the false back as before described.
It will thus be seen that the letters are eutirely safe from inspection or
handling by the messenger.
The entire arrangement of frame, box, and false back, can be reversed so as to
work downwards instead of upwards, or it may be arranged to work sideways when
more desirable to do so without affecting the principle of the invention.
Dated this 5th day of January 1892.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Agent for Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Letter Box.
1, HENRY COLEMAN, of 12 Jesse Terrace, Reading, in the County of Berks.,
Ironmonger, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in aud
by the following statement :-
This invention refers to letter boxes which are placed behind street doors to
receive letters through a slit in the door.
My improved letter box consists of two main parts, a metal or wood frame which
is fixed to the back of the door and a removable box of special construction which
can be attached to or detached from the frame.
My letter box is designed so as to enable the box containing the letters to
be removed from the door and conveyed to the owner by a messenger without
the said messenger having access to the letters.
I will now describe the invention with reference to the accompanying drawings,
in which
Fig. 1. is a back elevation of the interior of the letter box a with the door
at right angles.
b is the door.
c is the slide or false door.
d is the small bolt or sturl which engages with the top of the box.
e is the upper lock with key e¹ which locks into the head of the iron frame l.
fis the lock which secures the door.
f' is the key.
9 is the vertical catch with sloping jaw which engages with the horizontal spring
detent, bolt i.
h is the spring action guard which descends in front of the catch g and prevents
the detent bolt i engaging with g when the door b is closed. q' is the coiled spring
which presses it down. t is a bracket supporting the guard h.
i is the spring detent bolt which engages with the catch y when the slide c is
depressed before the door is opened.
is a shield enclosing the horizontal bolti and protecting it from contact with
the letters. .
Fig. 2 shows a back, elevation of the letter box a with the door closed, and the
slide c elevated so as to engage with the frame !. When in this position the
aperture is open to receive letters.
The dotted lines show the position of the top and aperture of the slide c
when drawn down and the aperture closed and the catch g engaged with the
bolt i.
Fig. 3 is a central section through the line 1, 2, of Fig. 2 showing a side view
of the slide c, in its elevated position and of the vertical catch g, stud d and
horizontal bolt when the door is closed and the box is ready to receive letters.
Fig. 4 is an enlarged central section of the catch g, spring guard h and bolt i
with its coiled spring 9 and bracket v, as in Fig. 3 and shewing the position of
this mechanism, when the slide c is depressed and the aperture of the box is
closed.
Fig. 5 is a front elevation of the iron frame with two flanges m, m, in the
upper corners of its back side which, together with the projecting ribs n, ne
shewn in Fig. 6.serve, as, a guide for the slide c. This figure also shows the
studs o, o, which engage with holes in the under side of the letter box a.
r. r. are lugs for fastening frame to street door. s is a cross bar serving as a
guide for slide c. wo is an iron plate fixed to the front of the iron frame, to
form with the flanges m, the chamber into which the slide c ascends.
Fig. 6 is a horizontal cross section through line 3-4, of Fig. 5 of the upper

page_text: art of the iron frame shewing.ribs n, flanges m and another rib p which
orm the chamber into which the slide c passes and is fastened by means of the
ock e.
It will be seen that when the frame is attached to the back of the door, the
by thrusting the upper part of the slide c under
box a can be readily attached to
he flanges m and allowing the lower end of the box to fall upon and engage with
the studs o. It can then be secured by the lock e, the slide e being drawn up for
this purpose whereby the slit r is opened by a similar aperture in the slide
coming opposite to the aperture, and the box is ready to receive letters.
An essential part of the invention is the arrangement by which the door bis
placed at the back of the letter box a so as to come into contact with the street
door. This ensures that the letters cannot be obtained until the upper lock e is
first unfastened and the box removed from the frame when the slide c must
be depressed and becomes fastened by the bolt and catch i, g. thus closing the
aperture. It follows from this arrangement that if a messenger be sent for
the letter box for which purpose he will be entrusted with the key e¹ and if
the key f of the door b, be retained by the principal, the letters can be obtained
only by the latter safe from any previous handling or inspection by the
messenger.
This arises from the fact that the letter box a is detained in the frame 1 by the
flanges m, m, which engage with the angular shoulders z of the slide c and until the
slide e is depressed so far as to pass clear of the flanges and cause the bolt and
catch i, g, to engage and fasten the slide, the box a cannot be released from the
frame.
When the door b is opened and the letters removed on the door being again
closed the guard / interposed between the bolt i and catch g. forces back the bolt i.
and prevents the slide being held down, so that the messenger when replacing the
box a in the frame l, has no difficulty in again elevating the slide c and locking it
as before.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. In a letter box, the combination of the box a and specially arranged door b
with the slide c, stud d, locks e. f, catch g, guard h, spring bolt i, shield k with
the frame as herein described and set forth.
2. In combination with a letter box as aforesaid the frame with its flanges m,
ribs n, lugs r. studs o and plate was herein described and set forth.
1000
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.