Improvements in Pillar and Wall Letter Boxes.
Year: 1899

page_text: Date of Application, 22nd Sept., 1899
Complete Specification Left, 22nd June, 1900-Accepted, 28th July, 1900
Improvements in Pillar and Wall Letter Boxes.
I, CHARLES EDWARD KNIGHT, of 135, Burnt Ash Road, Lee, Kent, Gentleman,
do hereby declare the nature of this invention to be as follows:
This invention relates to improvements in pillar and walls boxes for posting
letters and other postal packages and has for its object to prevent the latter from
being fraudulently abstracted or stolen when posted in the said boxes.
For this purpose the ordinary letter slot is closed after the letter is passed
through by a plate sliding vertically inside the box between the slot and an
inclined fixed plate.
Beneath the said fixed plate is pivoted a horizontal plate separating the upper
part of the box from the lower part, and upon each side of this plate is fixed a
toothed quadrant or sector which gears with racks or recesses on each side of
the sliding plate. The horizontal plate is pivoted upon knife-edge or scale
bearings, and it, and the sliding plate are arranged so as to exactly balance each
other.
Thus when a letter is posted it falls from the inclined plate on to the pivoted
plate, tilting the latter and raising the sliding plate so as to close the slot.
The letter then falls into the lower part of the box and the pivoted plate
resumes its former position thus lowering the sliding plate and opening the slot.
The inclined fixed plate serves as a guard to prevent any weighty article being
dropped upon the wrong end of the pivoted plate so as to interfere with its tilt-
ing action.
1000
I, CHARLES EDWARD KNIGHT, of 135, Burnt Ash Road, Lee, Kent, Butcher, 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 and by the follow-
ing statement :—
This invention relates to an improved letter box adapted for pillar or wall
boxes, for posting letters and other packages and has for its object to prevent the
fraudlent abstraction of the said letters or packages after they have been posted.
For this purpose the ordinary letter slot is provided with a plate arranged

page_text: so as to slide vertically behind the slot and close the latter after the letter has
been passed through and to open again automatically. This plate is fitted so as
to slide between the slot and an inclined fixed plate for guiding the letter into
the box, and underneath the inclined plate is pivoted a horizontal plate separat-
ing the upper part of the box from the lower or receiving part.
Upon one end of the pivoted plate, upon each side of the latter, is fixed a
toothed quadrant or sector whose radius is struck from the pivoted axis of the
plate.
The said toothed sectors gear with toothed racks or recesses fixed or formed
on each side of the sliding plate and operate the latter upon the pivoted plate
being tilted.
The horizontal plate is pivoted upon knife-edge or scale bearings so arranged
that it and the sliding plate exactly balance each other when in their normal
positions. Thus when a letter is posted it falls from the inclined plate on to
the pivoted plate, tilting the latter and raising the sliding plate so as to close
the slot.
This tilting of the horizontal plate causes the letter to fall into the lower
part of the box, the said plate then resuming its horizontal position and lowering
the sliding plate so as to open the slot for the next letter. The inclined fixed
plate serves as a guard to prevent any weighty article being dropped upon the
wrong end of the pivoted plate so as to interfere with its tilting action.
In the accompanying sheet of drawings Fig. 1 is a vertical section of a
postal pillar box with the parts of the improved mechanism in their normal
positions and Fig. 2 is a similar view with the parts in the position
they occupy when a letter has just been posted. Fig. 3 is an inside
sectional elevation of the upper part of the pillar box, and Fig. 4 is a sectional
plan of the same.
a is the pillar or postal box formed with a smaller upper part or chamber b.
c is the letter slot and the inclined plate fixed behind the slot for guiding the
letters into the box.
is the vertical sliding plate fitted between the slot c and the plate d, and f
is the horizontal plate shutting off the upper part 6 of the box from the lower
part a.
The plate is pivoted on the knife-edge bearings g and is provided with the
toothed sectors one on each side of the said plate. These sectors gear with
the racks or teeth i fixed to or formed on each side of the plate e.
As the letters or packages are posted they slide down the inclined plate d on
to the horizontal plate f thus causing the latter, by their weight, to be tilted into
the position shown in Fig. 2. The tilting of the plate f raises, by the action of
the sectors h, the vertical sliding plate d so as to close the slot c, and as the letter
or package falls from the pivoted plate f, the latter resumes its horizontal
position and the plate e is lowered to again open the slot c.
It will thus be seen that by the action of the pivoted plate f it will be im-
possible to abstract any letters from the lower part of the box, for any instru-
ment, string or other device used for the purpose would only be caught or
gripped by the closing of the plate f upon attempting to withdraw the said
device from the box.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
(1) The improved letter box comprising an upper chamber provided with a
letter slot and an inclined plate fixed behind the latter, a vertical plate sliding
between the slot and the inclined plate, a pivoted horizontal plate separating
the upper chamber from the lower part of the letter box, and toothed sectors
carried by the said plate and engaging with racks or teeth on the vertical sliding
plate, substantially as described.

page_text: (2) In an improved letter box the combination with the box a of an upper
chamber having a letter slot c and an inclined plate d, a plate e sliding vertically
between the slot c and the plate d, a horizontal plate f pivoted on knife-edged
bearings and separating the chamber b from the box a, toothed sectors h
carried by the plate f, and teeth or racks i carried by the sliding plate e and
engaging with the toothed sectors h for operating the plate e upon the plate f
being tilted, substantially as described.
1000
J. B. FLEURET,
Agent for the Applicant.
5, Hatton Garden, Holborn Circus, London, .E.C.