Improvements in Safety Envelopes.
Year: 1893

page_text: Date of Application, 9th May, 1893-Accepted, 17th June, 1893
COMPLETE SPECIFICATION.
Improvements in Safety Envelopes.
I, WILLIAM RINK DALES, of 403 Cass Avenue, Detroit, Michigan, United
States of America, Capitalist, 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 new and useful improvements in envelopes, especially
designed for use in registered letter service; in expressing money or small packages
of value, and in the transmission of valuable documents. Consisting in the con-
struction and arrangement of parts as fully hereinafter set forth, the essential
features of which being pointed out particularly in the claims.
The object of the invention is to produce an envelope, in which the formation is
such that the contents may be securely sealed therein and any tampering with
the envelope with intent to gain surreptitious access to the contents thereof may
be readily detected. This object is attained by the construction illustrated in the
accompanying drawing, in which ;-
;-
Fig. 1 is a plan of the blank from which the envelope is formed.
Fig. 2 is a view of the envelope with the sealing flap turned back.
Fig. 3 is a view of the envelope sealed.
Fig. 4 is an enlarged transverse section through Fig. 3.
Referring to the letters of reference, A designates the body portion of the
envelope, which is provided with the end flaps B and C respectively. The outer
ends of said flaps are provided with a slot a, the edges of which are reinforced by a
textile fabric facing al attached to the under face of said flaps, and which serves
to prevent said slots from tearing out. These end flaps are adapted to fold onto
the body of the envelope and to lap one onto the other so that the slots therein
will register. The flap C being uppermost, is provided with a gummed margin c,
to cause it to adhere to the flap B, which latter flap has a portion of its upper edge
cut away, as shown at all in Fig. 1, for purposes hereinafter stated.
D designates the side flap, which is adapted to fold onto the end flaps to form
the pocket of the envelope, as shown in Fig. 2, and is made to adhere to end flaps
by means of a gummed margin e. This side flap is also provided with a slot e¹
which is adapted to register with the slots in the end flaps when said side flap
is folded thereon. Said slot e¹ having its margins reinforced by means of a textile
facing e secured to the under face of the flap.
E indicates the sealing flap, which, like the end and side flaps, is formed integral
with the body of the envelope, and which is provided with a tongue 6 adapted to
enter the slots in said end and side flaps. This tongue is also provided with a
textile facing d, and this facing, as well as the margin f of the sealing flap, is
provided with a coating of gum.
To seal the envelope, the end and side flaps are folded as shown in Fig. 2, and
caused to adhere. The gum upon the tongue and margin of the flap E is then
moistened, and said tongue entered through the registering slots in the side and
end flaps, and is folded backward upon itself, as shown in Fig. 4, and its gummed
surface caused to adhere to the under face of both the end flaps, which is accom-
plished by cutting away a portion of the upper edge of the under flap B, as at a",
enabling the end of the tongue to lap onto the upper margin of the flap C. The
passage of the tongue through the slots in the end and side flaps, securely fastens
said flaps together, and prevents the envelope from being opened through any of
said flaps without first withdrawing said tongue, which is a difficult matter to
accomplish as said tongue is folded backward and made to adhere to the under
faces of the end flaps, in which position its gummed surface cannot be readily

page_text: reached by either steam or water, nor can an instrument be entered in any way to
disengage said tongue, without betraying the fact that the envelope had been
tampered with. As an additional precaution to prevent any effort being made to
open the envelope by steam or water, a soluble chemical substance, indicated at i
is placed between the facing and the body of the tongue, which, on the application
of either heat or moisture will liquefy and spread, thus indicating at once, the
attempt that had been made to open the envelope.
On referring to Fig. 1, it will be seen that the blank is provided with reinforcing
strips of textile fabric o, which are attached to the inner face thereof on the line
where the flaps fold onto the body of the envelope. These strips strengthen the
folds of the envelope and prevent the corners from wearing out, and also prevent
the envelope from being opened without detection, by cutting through the end
thereof, or by scraping through the envelope on one of its folds with a sharp
instrument and then replacing the pulp thus removed and pressing it into place,
in such manner as to appear that the envelope had not been opened, as has been
practiced.
This improved envelope, when sealed as shown in Fig. 2, does not differ in
appearance from the ordinary envelope, but in which the construction is such, that
surreptitious access to the contents thereof cannot be attained with positive
assurance of detection.
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 :-
Claim 1. An envelope comprising a body having end flaps adapted to fold onto
the body and provided with registering slots in their lapping ends, a side flap
adapted to fold onto the end flaps and having a slot therein that registers with the
slots in said end flaps, a sealing flap provided with a tongue that passes through
the slots in said side and end flaps and folds backward upon itself, substantially as
set forth.
Claim 2. An envelope comprising a body having end flaps provided with
registering slots, one of said flaps having a portion of its margin cut away adjacent
to its slot, a side flap having a slot that registers with the slots of the end flaps, a
sealing flap having an adhesive tongue that passes through said slots and adheres
to the under face of said end flaps.
Claim 3. An envelope comprising a body having side and end flaps which are
adapted to fold onto the body and are provided with registering slots having
reinforced margins, a sealing flap having an adhesive tongue provided with a facing
of textile fabric, said tongue passing through said slots and folding backward upon
itself and adhering to the under face of the end flaps.
Claim 4. An envelope comprising a body having side and end flaps adapted to
fold onto the body and provided with registering slots, a sealing flap provided with
an adhesive tongue adapted to engage in said slots and provided with a soluble
chemical substance.
Dated this 9th day of May 1893
ALLISON BROS.,
Agents for the Applicant.