Improvements in Letter Boxes and Attachments thereto.
Year: 1891

page_text: COMEINEN DIBUTION
[Communicated from abroad by GEORGE HARVEY, of the City of Winnipeg, in
the County of Selkirk, in the Province of Manitoba, Gentleman.]
Improvements in Letter Boxes and Attachments thereto.
I, CHARLES BARCLAY MCPHERSON CHAMBRE, of the Town of Antrim, in the
County of Antrim, Ireland, Land Agent, 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 following statement :-
This invention relates to improvements in letter boxes and attachments thereto
and has for its object to provide a means whereby when the front entrance to the
box is opened for the introduction of letters, an alarm will be sounded automatically;
to provide a means whereby an alarm may be sounded not only near the box but
also at a point distant therefrom; to so construct the box that it will be closed
automatically after the letters or papers have been deposited, and dust and rain
thereby excluded; and also, to construct the box and the attachments that they
will be durable and simple and capable of being manufactured at a minimum of
cost and made of an ordinary small size, and an ornamental attachment to the house
door and greatly preferable to a large and cumbersome box.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended two explanatory sheets of drawings in the several
figures of which corresponding parts are marked with the same letters of
reference.
Figure 1 is an elevation showing the inside of the front face of the box and the
attachments thereto, secured to a door.
Figure 2 is a front elevation of a portion of a door illustrating the construction
of the outer face of the letter box opening and plate.
Figure 3 is a vertical section showing the cover of the letter box and arms
attachment.
The letter box A may be made of any suitable metal or material and approved
construction, and it is provided preferably with a metallic or wooden front B
adapted to be attached to the door or partition C, and it is also provided with a
rear door D whereby the contents of the box may be readily and conveniently
removed.
In the front face of the box A near the top thereof a transverse opening E is
provided which opening extends through the door C and is adapted to form an
inlet for the letters. The opening E is closed normally by means of a plate F
which is located outside the said opening E in the door C and pivotally supported
at its lower edge in such manner that its upper edge will swing freely inwards and
downwards towards the letter box A, and when closed its upper edge will shut
against a plate H located on the outside of the door C and extending around the
opening E. To each of the immer ends of the plate Fan arm G is fixed which
extends inwardly, and to each of these arms another arm I, seen more particularly
in Figure 3, is pivoted, extending in an upward direction. On one of these arms I
a short projection J is made for the purpose of engaging a hammer K in its path
when the plate is being opened. To the upper end of the pivoted arm I a chain or
cord L is attached which passes over a pulley M and extends downward into a
tube N and attached to a weight O of lead or other suitable metal or material, as
shown by dotted lines, inside the tube N, and arranged to move freely therein.
Above the letter box opening, on the front face of the box A, a gong or bell P is
located, and beneath this gong the spring hammer K is fixed, one end of the
hammer K being located in the path of the projection J on the arm I, so that when
the letter box is being opened on the outside for the insertion of letters the arm I

page_text: with its projection J will be carried downward, engaging the hammer K, which
when carried to a certain point is released, and springing upward, will strike the
gong or bell P, and thus sound an alarm. The arm G pivoted to the other end of
the plate F has at its upper end a projection R, upon the lower side of which an
insulated plate of metal S is fixed for the purpose of coming in contact with the
wires T T, and thus forming an electrical connection through the wires T T by a
battery and connected to an electric bell at any point in the house where desired,
so that an alarm may be sounded both at the letter box and at some distant point if
so desired electrically.
A wire connection U may also be effected between the upper end of the arm I
and a bell located at any desired point in a building, and this connection is usually
effected by securing one end of the wire U to the upper end of the bar I passing
the wire over a friction pulley or roller upward to any suitable form of gong or bell;
as for instance, the wire at its upper end may be connected with a bell crank lever,
and a spring made to intervene the bell crank lever, and the wire or any other well
known mode of attachment to the bell may be employed.
In operation, the covering plate F, Figure 2, is pushed inward and downward
from the outside, and when so pushed, the opening E in the letter-box is uncovered,
and the letters may be readily dropped into the box. As the plate is carried
inward to uncover the opening the insulated plate S is carried down by the arm I
and brought into contact with the wires T T completing the electric current and
sounding an alarm on the distant bell, and the wire U is carried downward by the
arm I, and an alarm is sounded on the distant bell, and the projection J on the
bar I in its downward path engages the extremity of the spring hammer K which
is carried downward to a certain point and released from contact with the projection
it is thrown upward and an alarm is sounded on the gong or bell P. When the
cover plate F is released it is automatically thrown back, and the opening to the
letter box closed through the medium of the lead or weight O and the wire or
cord L and pulley M.
It will thus be observed that each time the opening to the letter box is uncovered
an alarm is positively sounded, and if the electrical connection is effected the alarm
will continue to be sounded until the plate F is released and the opening closed,
thus assuring a reasonable amount of security against the abstraction of letters from
the box after having been deposited.
It is to be understood that although I have described and shown the letter box
with a closed front I may make it with an open one, in which case the several
attachments would be fixed to the inside of the door itself.
It is also to be understood that in place of the weight and chain as hereinbefore
described, I may use a spiral or other spring.
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 device of the character described, the combination with the cover plate
of a letter box and a gong or bell, of an arm projecting from either end of said
cover plate, of projecting pins on said arms, of a spring hammer secured at one end
and having its free end projecting into the path of the projecting pin on one of the
bars, the shank of the hammer being spring fulcrumed, substantially as and for the
purposes hereinbefore specified.
2. In a device of the character described the combination with a weight con-
trolled cover adapted to cover the inlet opening of a letter box and a gong or bell,
of projecting bars formed upon the ends of said cover, a projecting trip pin on one
of the bars projecting over the extremity of a hammer located in the path of said
projection, the other extremity of the hammer being firmly held in position, as and
for the purposes herein before specified.
3. In a device of the character described, the combination with a letter box of a
covering plate to the inlet entrance, a gong or bell located in or near the box, and

page_text: a distant gong or bell, a trip bar projecting upward from the inner side of the letter
box opening, a projection near the upper end of said bar to which an insulated plate
is secured in such manner that when the plate covering the inlet opening is
depressed it will carry the bar downwards with its insulated plate and into contact
with insulated wires, and a distant electrically controlled bell or gong, all as and
for the purposes specified.
Dated this 3rd day of September 1891.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.