Year: 1888

page_text: I, THOMAS WILLIAM DANCE, of 2 Vernon Terrace Gateshead on Tyne in the
County of Durham, Merchant, 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:-
The object of this invention is to produce an envelope from which the contents
cannot be abstracted or lost unless part of the said envelope is cut or damaged in
some way. The invention being more particularly designed to prevent the fraudulent
or accidental opening of envelopes by the aid of steam or other mode of damping
which the existing forms of envelopes are liable to and so, do not safeguard the
contents. The envelope is provided with two flaps, one of which is fixed on or in the
back of the envelope or made in one piece with the said back and is intended to be
folded inwards and gummed, or otherwise fastened to the front of the envelope inside
whilst the other flap is intended to be fastened down outside over the back in the
ordinary way.
And in order that my invention may be more fully understood and carried into
practice I will now proceed to describe the same with reference to the accompanying
drawings, in which similar letters indicate corresponding parts in all the figures.
Fig. 1 is a perspective view of the double flapped envelope.
Fig. 2 is a transverse section of the same.
Fig. 3 shews the shape or configuration of which the invention is cut, the dotted
lines indicating where the same is to be folded when making up the envelope; and
Fig. 4 shews a modification of my invention which is intended to be attached to
the inside of the back of an ordinary envelope by gumming or otherwise fixing the
part F thereto.
The flap B is gummed on the face shewn uppermost in figure 3 and the flap A is
gummed on the reverse or under face.
To make the envelope, the piece shewn in figure 3 is folded along the five dotted
lines a, b, c, d, e, f, a e and b d as follows :-
The flap A is folded along the line e, f on to the part F, so that the gummed
reverse or under face of A will now be uppermost. The parts C, B, D & F are now

page_text: folded and fastened together as in the ordinary envelope the end flaps C. & D. being
gummed for that purpose. The double flapped envelope is now complete the contents
intended therefor are inserted between the two parts E & F, the flap A is now
gummed against the back of the front or face E as shewn at y figure 2 and the flap B
fastened down outside in the ordinary way.
It is obvious that if any unprincipled person opens the outer flap B by steaming or
by any other means, the flap A will still be held tightly against the back of E, and
before the contents can be abstracted, the envelope will have to be damaged either by
cutting the flap A or by the application of further steaming or otherwise damping
which will tend to damage the front or face E.
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) The construction of an envelope, with two gummed flaps substantially as and
for the purpose hereinbefore set forth and illustrated in the accompanying
drawings.
(2) The construction of a gummed flap piece A to be attached to the inside of the
back of an ordinary envelope by gumming or otherwise fustening the part F thereto,
substantially as described and illustrated with reference to Fig. 4.