Year: 1897

page_text: I, FRANK FISCHER, of 30 Dale Avenue, in the City of Paterson, County of
Passaic, and State of New Jersey, U.S.A., Gentleman, 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:-
My invention relates to envelopes so constructed 'as to render clandestine
opening impossible.
Its object is to provide envelopes answering the above purpose, of simple
construction and which can be easily manufactured and will not be more expensive
than ordinary mailing envelopes.
The invention consists in certain details of improvement, and in the combination
of parts, substantially as will be hereinafter more fully described and finally
embodied in the clauses of the claims.
In the accompanying drawing,
Fig. 1, represents the blank of my improved envelope, spread open;
Fig. 2, a back view of my improved envelope with its closing flap opened and
Fig. 3, an enlarged central sectional view of the envelope, when closed.
In said drawing a represents the envelope having the side flaps b, b, the lower
flap e and the upper flap d; the side flaps b, with their projecting portions c, are
provided at their lower edges with tongues c', having their curved edges incised,
as at c 2 and adapted, when the flaps are folded together (as in Fig. 2) to form
a segmental shaped tongue-to correspond substantially in shape and size to the
curved portion d' of the upper flap d.
The lower flap e is provided with a substantially V-shaped incision e¹, the sides
of which are preferably parallel to the edges of the said flap, and are of a size
large enough to permit the insertion of the curved portion of the upper
flap d.
A cord g is placed within one of the folds of the envelope and is secured thereto
by glue.or in any desired manner; said cord projects beyond the respective edges
of the envelope, and will facilitate the opening of the same, as will be manifest.
The upper flap is covered along its inner edge with an adhesive substance,
which when folded will fall on the edges of the lower flap, and its curved portion d',
after being inserted through the cut or incision e¹, exactly upon the incised
edges c2, c2 of the tongues c¹, cl, to which it adheres.
The inner edge of the V-shaped flap e 2, formed by the incision e¹ is also
provided with an adhesive substance, which, when moistened will adhere to the
outer surface of the upper flap d as will be manifest.
From the foregoing it can be seen, that the envelope, when once closed, cannot
be opened clandestinely, as the incised edges of the tongues c¹ would necessarily be
torn off; furthermore, additional safety is rendered the envelope by having the
upper flap penetrating the lower flap.
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 combination with the side flaps of an envelope, of a curved tongue
projecting from each of said flaps and having their edges incised, substantially

page_text: 2. In an envelope, the combination with the side flaps and the upper flap, of
a curved tongue projecting from the lower edges of each side flap and having
their curved edges incised, said tongues when folded together to correspond sub-
stantially in shape and size to the curved portion of the upper flap and to be
engaged thereby, substantially as described.
3. In an envelope, the combination with the side flaps, the upper flap and the
lower flap, of a curved tongue projecting from the lower edges of each side flap
and adapted to be engaged by the inner surface of the curved portion of the
upper flap, and a substantially V-shaped flap formed within the lower flap by a
V-shaped incision, and adapted to engage the outer surface of the curved portion
of the upper flap, substantially as and for the purposes described.
4. The combination with the flaps of an envelope, of a substantially V-shaped
flap formed in the lower flap, and a curved tongue projecting from each side flap
and having their edges incised, the said tongues being adapted to be covered and
engaged by the inner surface of the curved portion of the upper flap, whilst the
outer surface of the said curved portion of the upper flap is adapted to be engaged
by the inner surface of the lower flap, substantially as and for the purposes
described.
Dated this 5th day of February 1897.
J. P. BAYLY,
18 Fulham Place, London, W., Agent for the Applicant.