Improvements in Paper Bags.
Year: 1889

page_text: Date of Application, 18th June, 1889-Accepted, 26th Oct., 1889
COMPLETE SPECIFICATION.
Improvements in Paper Bags.
I, CHARLES BOUGHTON STILWELL, residing at Number 1411, Jefferson Street, in
the City and County of Philadelphia, State of Pennsylvania, one of the United
States of America, Mechanical Engineer, 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 that class of paper bags which may be called bellows-sided
satchel-bottomed bags; and my object is to so construct such bags that they may
have the greatest possible capacity with the least possible consumption of paper while
at the same time the strength and correct proportions of the bag are in no wise
impaired.
The method or process of making a paper bag apart from the instrumentalities
employed, is of course the mere making of folds, or folds and cuts in the paper; by
which folds and cuts the finished bag resulting from the treatment is best
described.
As with all bags of the kind referred to, the first step is to form a strip of paper
into a tube with inwardly-tucked or bellows-folded sides; this is usually done by
well known mechanism acting on long rolls of paper which, after being folded and
pasted into a tube of the proper cross-section, is cut up into bag blanks. In or before
cutting off the blanks any desired slits or lips can of course be formed on its ends,
and I make a peculiar novel cut which however, can best be described hereafter. Tho
blanks being formed, the next step is to open up that portion of the tube which is to
be formed into the bottom, forming what in satchel-bottomed bags made from
untucked tubes, is called the "diamond which name I will hereafter use to describe
this part. This diamond is formed in the usual way except that in my method I take
care that the portion of the blank folded into the diamond shall be, (not considering
a lip on one edge of the bottom of the blank and which will be hereafter described)
substantially equal in length to half the breadth of the inwardly-folded or tucked-in
sides; as a result of this the two trapazoidal side folds of the diamond will each have a
maximum breadth about equal to one-half of the breadth of the folded-in sides, and
from end to end their length will be substantially twice the breadth of said sides.
"
It will be at once understood that the consequence of this construction will be that
each of the two final folds by which the bottom is closed and the bag completed will
be equal in depth to one half of the breadth of the folded-in sides of the blank and as
the bottom has of course the same breadth as the folded-in sides, these final folds will
just about meet without lapping in the center of the bottom.
Now if these folds instead of approximating, exactly corresponded with the
dimensions referred to, the result would be that the bottom would be just barely
closed up, without, however, leaving any room for the necessary paste seams to hold
it together. In order to overcome this difficulty so far as the securing of the final
folds to the edge of the side folds of the diamond is concerned, I make in the
bottom of the blank, slits both in the front and back thereof, equi-distant from the
center line, and distant from each other the distance between the two side folds of
the diamond plus a distance equal to twice the necessary depth of a pasted seam (say
about an inch as a seam should have a half-inch of paper to receive and hold the
paste.) The depth of these slits will be the distance from the edge of the paper to
the lines of folding of the edges of the diamond. These slits will leave parallel-sided
flaps on each end of the diamond which, when the final folds are made, will lap over
the side folds for their entire length and to an extent sufficient to enable a strong
pasted seam to be made between them. In order to secure the necessary overlapping
of the final folds at the center of the bag, I in cutting the blanks from the tube,
form on one edge of the portion to be formed into the bottom a projecting flap of a
D

page_text: depth sufficient for a pasted seam (say about half an inch) and a breadth which
should be about the same as the distance between the slits already referred to
although the exact breadth or form of this flap is not of the essence of this invention
so long as it serves its purpose as hereafter described.
In cutting blanks from long tubes, this flap is cut out from the top of the
adjoining blank leaving a thumb hole which is in no wise objectionable. Of course
the provision of this flap overcomes the last difficulty in forining the bag enabling
the two final folds to lap and be pasted together in the most approved and secure
manner.
The bag made by this process will, I believe, require less paper for any standard
size of bag than any other bag of a similar construction and said bag is also a
thoroughly good and merchantable one.
Reference being now had to the accompanying drawings which illustrate my
invention, and in which-
Figure 1, is a perspective view of the bag blank ready for folding into my
improved bag.
Figure 2, is a top view of the same blank.
Figure 3, represents the blank as it appears when the diamond has been opened
out.
Figure 4, represents the completed bag.
Figure 5, shows in perspective tho bag opened up, and
Figure 6, is a perspective view of a slightly modified form of my bag.
A, designates the blank. B, represents the front, and, C, the back of the bag
blank. D, D', are the folded-in sides of the blank. b, b, are the front corners, and,
c, c, the back corners of the blank. ¹, ¹, indicate the two slits made in the front,
B, of the blank, and c¹, c', the two slits made in the back C, of the blank 6', c³, being
the flaps which these slits form. c, is the extended or prolonged flap which I make
on the front or back of the blank; as shown, it is on the back and forms a
prolongation of the flap, c³. c, indicates a portion at the top of the back, C, of the
blank which is cut away to form the flap, c, on another blank when the blanks are
cut out of a long tube of paper. d, is the central fold of the tucked-in sides by which
they are divided evenly into laps, D, and, D', as shown.
The first step in making the bag is to select the line on which the diamond shall be
opened. E, Figure 2) indicates such a line which must be at a distance from the
bottom end of the blank equal to the breadth of the tucked-in side; that is, the
distance, e, e, (Figure 2) must be substantially equal to the distance, f, f, (Figure 5)
which is of course the breadth of the sides of the bag.
The next step in making the bag is to open up the diamond on the line, E, which is
accomplished by folding back the upper plies of the paper on that line, the tucked-in
sides thus forming the inward triangular folds indicated by the dotted lines converging
from ff in fig. 3 and the portions of the sides which extend below these triangular
folds being then folded down upon them so as to form the truncated triangular
folds F Figs. 3 and 6 which form the side folds of the diamond; the slits, 61, and, c',
having been made so that the flaps, 63, and, c³, shall be as much broader than the
distance between the two side flaps, F, as may be necessary to enable them, when
folded down, to over-lap such flaps sufficiently to form a pasted seam therewith. The
final folds of the bag are made by folding the two ends of the diamond, which I have
marked, G, and, G¹, on the lines, f, f, and, f¹, f¹, respectively.
The result of these final folds is seen in Figure 4, which shows, that while the
flaps, b, and, c, just meet at the center of the bottom, the prolonged flap, c³, over-laps
the flap, 63, enabling the flap, G, and the flap, G₁, to be properly secured together,
while each of such flaps is secured to the side folds, F, by the over-lapping edges of
the flaps, 63, and, c, and any desired lines of pasting on the parts behind such flaps.
Figure 6 represents the prolongation, 6, on the flap, 63, similar to the pro-
longation, c, on the flap, c. Such a construction is of course perfectly feasible, but
has I believe, no good quality which makes it preferable to the plan shown in the
other Figures of the drawings.

page_text: While of course the flap, G³, could be folded down first, and the flap, G, folded on
top of it, I believe that it will be found more convenient to secure the flap, c³, on the
flap, 63, rather than to secure the flap, 63, on the top of the flap, c
To avoid confusion in the lines, I have omitted to represent in the drawings the
usual lines of paste by which the flaps, G, and, G¹, are secured to each other and to
the side folds, F, F, in forming the bottom.
To all skilled in the art, it will be obvious how and where such paste lines should
be applied, and it is therefore unnecessary to further refer to them.
In the drawings I have, for the sake of clearness, represented the flap, c³, as
narrower than the flap, c³, of which it is a prolongation; in practice however, these
flaps should be of the same breadth, at least the base of, c', should be as broad as, c²
its corners may be curved if desired.
;
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-
"As a new article of manufacture, a bellows-sided satchel-bottomed paper bag
having its bottom formed with side folds substantially equal in breadth to one-half
the breadth of its tucked-in sides; its final folds formed with parallel-sided flaps of
such a breadth that they will over-lap the side folds sufficiently to form a strong
pasted seam therewith; and a prolongation of one of the flaps sufficient in length to
over-lap and form a pasted seam with the other flap."
Dated this 18th day of Inno 1000
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.