Improved Mechanism for Preventing Theft of Letters and Parcels from Pillar and other Letter Boxes.
Year: 1890

page_text: Date of Application, 7th June, 1890
Complete Specification Left, 7th Apr., 1891-Accepted, 16th May, 1891
PROVISIONAL SPECIFICATION.
Improved Mechanism for Preventing Theft of Letters and Parcels
from Pillar and other Letter Boxes.
I, CHARLES JOHN TOZER, of 27 High Street, Plymouth, in the County of
Devon, Contractor, do hereby declare the nature of this invention to be as
follows:-
This invention relates to letter boxes in "pillars," walls, doors and in like or
analogous positions or places.
It consists in a trap for preventing fraudulent extraction, from such boxes, of
letters and other documents and parcels.
The trap which is in the form of a three-sided box is designed to be fixed inside
the pillar or other letter box to which it is applied.
Hinged in the sides of the trap and extending across it towards the top thereof
is an inclined plate provided at the lower edge with a rod or arm which at one end
extends into a slot formed in a vertical plate arranged at a short distance from and
parallel with one side of the trap frame. The inclined plate normally hangs on its
hinge in such manner as to leave sufficient space between its lower edge and the rear
wall of the trap frame for the passage of letters and other packets or parcels inserted
in the usual aperture.
At the bottom the trap is fitted with a counter-weighted plate, serrated at
the lower end, hinged at one side in the frame and at the other in the vertical
plate above mentioned. This vertical plate may conveniently be termed a
false side.
The letters and other packets on being inserted in the aperture provided therefor
are received upon the counterweighted bottom which yielding to the additional
weight is depressed on its hinges and allows the letters and other packets to slide off
into the compartment below. The bottom then swings back to its normal angle.
In event of an attempt being made to obtain access to the letters by forcing down
the bottom of the trap, a rod attached thereto and extending upwards behind the
upper plate is by the tilting of the bottom brought into contact with the back of the
upper plate which is in consequence pressed upwards and against the inside of
the back of the trap and closes the passage to the lower part of the trap.
The rod or arm above referred to as carried at the lower edge of the upper plate
is, by the said movement of the plate, pushed back in the slot in the false side and
bears against a bent lever pivotted between the false side and the actual side of the
trap. This lever is jointed at the upper end to another arm outside the back of the
trap, which arm, acting upon a third plate hinged to the back of the box, moves
the said third plate forward bringing it immediately under the upper plate,
effectually barring fraudulent access to that part of the box designed for containing
the letters and parcels.
Dated this 6th day of June 1890.
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.

page_text: +
COMPLETE SPECIFICATION.
Improved Mechanism for Preventing Theft of Letters and Parcels
from Pillar and other Letter Boxes.
1, CHARLES JOHN TOZER, of 27 High Street Plymouth, in the County of Devon,
Contractor, 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 letter boxes in "pillars," walls, doors, and in like or
analogous positions or places. It consists in a trap for preventing fraudulent
extraction from such boxes of letters, and other documents and parcels.
The trap which is preferably made in the form of a three sided box is designed
to be fixed inside the pillar or other letter box to which it is applied.
In the accompanying drawings
Figure 1 is an elevation partly in section shewing the letter box trap as applied
to an ordinary door, and
Figure 2 is a section taken on the line X. X., Figure 1.
Figure 3 is a vertical section of a modification.
Similar letters of reference are used to indicate the same or corresponding parts
in all the figures.
Referring first to Figures 1 and 2 :-Hinged in the sides Q, Q, of the trap and
extending across it is a shutter plate C. sufficiently long to reach when raised to a
horizontal or nearly borizontal position to the rear or back O of the trap. This
shutter plate C is counterweighted and is hinged just immediately below an inclined
plate S also extending across the trap and fixed to the sides QQ thereof, which
said plate S when the trap is placed in correct position on the door forms a con-
tinuation of the aperture P and acts as a kind of shoot for the letters and other
documents or parcels passing therethrough see Figure 2. The hinged shutter plate C
is weighted or hung upon its hinges in such a manner that it tends to hang in a
vertical position but is kept in an inclined position as shewn in Figure 2, by means
of suitable stops; when in its normal position therefore letters, documents and
parcels passed through the aperture P will be deposited on the bottom plate A. the
action of which will be explained hereafter.
On one of the lower corners of the shutter plate C is fixed a short rod or arm M,
the outer end of which extends into a slot E formed in the vertical plate or false
side R the said false side being arranged at a short distance from and parallel with
one side Q of the trap frame (see Figure 1). The said slot is curved to the arc
of a circle whose centre is at the hinge N of the shutter plate C, so that the rod M
on the end of said plate Ċ will travel in the said slot as the plate C is raised or
lowered. On a pin H fixed between the side and false side R is pivoted one end of
a connecting rod D whose other end is jointed at J to the upper end of a lever G
whose fulcrum is at E. The other arm of this lever G forms part of or is affixed to
a second shutter plate I similar in construction to the plate C. As the plate C is
raised the rod M riding in the slot F bears against the connecting rod Dand pushes
the same backward thereby pushing the upper end of the lever G backward and
turning the same on its pivot E thus raising the plate K beneath the plate C. If
desired a false side R may be provided for each side Q of the letter trap and each
lower corner of the shutter plate C provided with a rod or arm M the mechanism
for actuating the plate K being duplicated on each side, but I have only shewn
this mechanism as applied to one side of the shutter plate C as I find this to be
sufficient.
The third shutter or bottom plate A is hinged to the sides QQ of the trap and
is similar in construction to the other two shutter plates C and K, and is counter
weighted at T so that its normal position is to close up the bottom of the trap thu
forming a false bottom as shewn in Figure 2. On the hinge U of the bottom plate A

page_text: is pivoted a lever B normally resting under the shutter plate C and brought into
action by means of the projection V when by the weight of a letter etc. the bottom
plate A is turned on its hinge.
The action of the trap is as follows:-The letters and other packets on being
inserted through the aperture P are deposited on the counterweighted bottom
plate A, which yielding to the additional weight is depressed on its hinges and
allows the letter and other packets to slide off into the compartment below, when
the bottom plate A. returns to its normal position. In the event of a fraudulent
attempt being made to obtain access to the letters by forcing down the bottom
plate A the lever B is by the tilting of the bottom plate A brought into contact
with the underside of the shutter plate C which is in consequence pressed upwards
and against the inside of the back O of the trap thereby closing the passage to the
lower part of the trap. Meantime the rod M travelling in the slot has been
caused to bear against the connecting rod D which in its turn has actuated the
second shutter plate K bringing it forward immediately under the shutter plate C
thereby locking the said plate C and effectually barring fraudulent access to that
part of the box containing the letters and parcels. One or all of the plates C, K
and A may if desired be toothed, serrated or jagged along their lower edges so as to
entangle string, wire and other articles fraudulently inserted between them.
Figure 3 shews a simpler form of my invention wherein the locking mechanism
at the rear of the trap is dispensed with, the trap consisting simply of the shutter
plates C and A and the lever B, for closing the shutter plate C when the bottom
plate turns on its hinge. The construction and action of these parts is the same as is
hereinbefore described with reference to Figures 1 and 2.
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) A letter box trap consisting of the counterweighted hinged bottom plate A
carrying the rod B which bears against the underside and raises the hinged shutter
plate C as and when the bottom plate A is depressed the said plate C as it is raised
causing the hinged plate K to be also raised and to close up immediately beneath it
by means of the rod M, slot F, connector D, joint J, and lever G or their
mechanical equivalents all combined and operating substantially in the manner and
for the purpose hereinbefore set forth and illustrated in Figures 1 and 2 of the
accompanying drawings.
(2) The modified form of my invention substantially as described with reference
to Figure 3 of the accompanying drawings and for the purpose stated.
(3) The improved mechanism herein described for preventing the theft of the
contents of letter boxes substantially as set forth.
Tared this 7h day of
of ADTH 1031
WALCA THIS ALN (BAY OL ADTI 1031,
CASTLE SMITH,
Per F. W. Golby,
"Invention" Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.