US2582286A

US2582286A - Bag closure

Info

Publication number: US2582286A
Application number: US754987A
Authority: US
Inventors: Arthur E Schenck
Original assignee: Bemis Brothers Bag Co
Current assignee: Bemis Brothers Bag Co
Priority date: 1947-06-16
Filing date: 1947-06-16
Publication date: 1952-01-15
Anticipated expiration: 1969-01-15

Description

Jan. 15, 1952 A. E. SCHENCK BAG CLOSURE 3 Sheets-Sheet 1 Filed June 16, 1947 INVENTOR. AETHl/E E. ScHEA/cK 1, ATTORNEYS A. E. SCHENCK Jan. 15, 1952 BAG CLOSURE 3 Sheets-Sheet 2 Filed June 16. 1947 ZNVENTOR. ARTHUR E JCHENCK BY fie,

ATTORNEYS Jan. 15, 1952 A. E. SCHENCK BAG CLOSURE 3 Sheets-Sheet 3 Filed June 16, 1947 INVENTOR. E. ScHE/vcK Y flail, w W

ARTHUR ATTORNEYS Patented Jan. 15, 1952 BAG CLOSURE Arthur E. Schenck, Woodhaven, N. Y., assignor to Bemis Bro. Bag Com a corporation of Miss pany, Minneapolis, Minn., our! Application June is, 1947, Serial No. 754,987

1 Claim. 1

, This invention relates to new and useful improvements in bag closures and more particularly to closures for sealing the open tops of flexible walled bags of the intucked type, and wherein the bag top walls are pressed into flatwise relation before sealing the bag mouth.

. Numerous attempts have heretofore been made to develop a bag closure which would be simple and inexpensive in construction, and which when completed would positively seal the bag mouth against leakage and sifting. Bags have heretofore been made wherein one of the bag top walls was projected above the remaining bag top walls to provide an integral flap extending the width of the bag mouth, whereby when the bag top walls were pressed into flatwise relation, said flap could be folded over the flattened bag top walls and secured to the face of the opposite wall, thereby to seal the bag mouth. In such closures it has been extremely difllcult to render the corners of the sealed bag top siftproof, because portions of the contents of the bag, particularly if finely pulverized, would find its way between the plies of the flattened bag top walls to the extreme corners of the bag top at each end thereof where it might sift through because of the inability to tightly seal such cornersby folding the extended flap into sealing engagement with the opposite wall, as above described.

To overcome the difliculty now commonly experienced with such bag closures, and particularly with bags of the intucked type, I have found that by providing what may be termed the back wall of the bag top with an upwardly projecting flap, and then forming the top of the bag walls in such a manner that the top edges of the intucked edge walls are disposed at an elevation above the edge of the front wall of the bag top, that a leakand sift-proof closure may readily be obtained by folding the extending flap of the rear wall and the projecting ends of the intucked walls over into fiatwise relation with the upper portion of the front wall, and then adhering the flap and portions/of the edge walls to the front wall by a suitable adhesive, that the danger of leakage or sifting of the contents of the bag therefrom at the corners of the bag closures may be completely eliminated.

It is therefore an object of the present invention to provide a closure for bag bodies of the intucked type, whereby the mouths of such bags may be closed and sealed in a manner to positively prevent leakage or sifting of the contents from the bags through the closed tops thereof, even A further object is to provide a tubular bag body blank of the intucked type having one of relatively wider walls projected upwardly above the top edges of the remaining bag top walls to provide an integral closure flap, and wherein the upper marginal edge portions of the intucked walls are disposed at an elevation between the upper and lower edges of the relatively wider walls of the bag body, whereby when the upwardly projecting closure flap is subsequently folded over into fiatwise engagement with the opposed or front wall on a line coincident with the top edge of said opposed wall, or along a fold line spaced downwardly from the upper edge of the opposed wall, the projecting ends of the intucked walls are simultaneously folded into flatwise engagement with the opposed or front wall and adhered thereto by a suitable thermo-plastic or other adhesive suitable for the purpose. thereby to effect a closure which will be leakand sift-proof.

Other objects of the invention reside in the provision of a bag closure which is particularly well adapted to bags of the intucked type, whereby the bag mouth walls may be expeditiously folded into closing and sealing relation to provide a hermetically sealed closure which will withstand rough handling without danger of the contents thereof sifting from the corners or ends of the closed bag top; in the manner of trans versely severing the tube from which the tubular bag body blanks are formed whereby an upwardly projecting integral closure flapis provided at the top of the bag body without waste, and without in any way interfering with the formation of the bag bottom; and in the formation of the upper marginal edge portions of the bag top walls whereby a seal tight closure may be effected with a minimum of operations.

Other objects of the invention will appear from the following description and the accompanying drawings and will be pointed out in the annexed claim.

In the accompanying drawings there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claim which follows.

, In the drawings:

Figure 1 is a front view of a tubular bag body blank showing the novel arrangement of the bag top walls prior to being folded into closing and though the bags .are roughly handled in transit. sealing relation;

' the bag top, the intucked edge walls being shown extending above'the top edge of the front wall;

Figure 7 is a similar view showing the integral flap of the rear wall partially folded over the upper marginal edge of the front wall; 7

Figure 8 is a view showing the completed 010- sure;

Figure 9 is a detail sectional view substantially on the line 9 of Figure 6, on a larger scale;

Figure 10 is a detail sectional view on the line v Ill-l0 of Figure 8;

Figure 11 is a detail sectional view on the line "-4! of Figure 6;

Figure 12 is a detail sectional view on the line i2l2 of Figure 8;

Figure 12-A is a side elevation of a closed bag top, artially broken away to illustrate the intucked wall portions folded against the front wall;

Figure 12-B is a detail sectional view similar to Figure 10, showing a bag top closure wherein the bag top walls are folded transversely along the line b-b, shown in Figure 6; and

Figures 13, 14 and 15 are views showing the formation of a self opening square bag bottom of more or less conventional design.

In the selected embodiment of the invention herein disclosed, there is illustrated in Figures 1 and 2, a tubular bag body blank comprising front and

rear walls

2 and 3, and opposed edge walls 4-4, shown intucked between the front and rear walls.

An important feature of the present invention resides in the formation of a closure which, when sealed, will be substantially sift-proof in construction, whereby finely pulverized materials may be safely shipped in the bags or containers without danger of leakage or portions of the contents of the bags sifting therefrom at the corners of the closed bag tops.

The novel closure herein disclosed requires that the transverse severing of the tube from which the tubular bag body blanks are out be such that when the tubular bag body blanks are cut from the tube, the upper edge 5 of the front wall 2 will be disposed at an elevation below the upper edge 6 of the rear wall 3, and the upper edges I of the intucked edge walls 44 will be disposed between the

upper edges

5 and 6 of the front and rear walls, respectively, as clearly illustrated in Figures 1 and 6. In other words, if the blank from which the bag body is made is opened up or stretched out, as shown in Figure 3, the upper edge of the blank will be upwardly stepped from its opposed edges, and the lower edge will be similarly stepped or notched to provide the top edge of the next following body blank.

The dot and dash lines 8 and 9, shown in Figure 3, indicate fold lines, and lines ii and I2 indicate similar fold lines, whereby the blank is divided into the front and

rear panels

2 and 3, respectively, and edge wall panels 4-4. The narrow elongated panel l3 shown at the right side of Figure 3 provides a pasting flange to which the marginal 4 edge portion") of panel 2 is pasted in the formation of the tubular bag body blank, shown in Figures and 2.

By severing the tube as above described, when the tubular bag body blanks are formed in the usual manner, the upper marginal edge portion of the rear wall will form, in effect, a flap l4, which extends above the upper edges of the front and

edge walls

2 and 4, respectively, of the bag top, as clearly illustrated in Figures 1, 6 and 7.

To close and seal a bag top in accordance with the present invention, the upper intucked edge wall portions and the flap i4 are folded over the upper edge 5 of the front wall 2, and are suitably bonded to the front wall by a suitable adhesive. indicated at 15 in Figures 6 and 7. In practice it has been found that a thermo-plastic or thermosetting adhesive adequately lends itself for use to secure the bag top walls in closing relation, because they require heat and pressure to complete the seal whereby the adhesive will flow into all of the crevices and interstices of the bag top walls to thereby render the sealed bag tops sift-proof and leak-proof, when completed as shown in Figure 8.

The folding of the upper projecting portions of the edge walls 4 over the top edge of the front wall simultaneously as the flap [4 is folded into sealing engagement therewith, is of extreme importance because by so folding the upper ends of the edge walls over the front wall, there is no possible way that the contents of the bag body may sift between the plies of said walls to the atmosphere.

To close a bag top such as herein disclosed, the flap I4 and the exposed upper edge portions 'll of the edge walls 4--4 may be folded along the line H into engagement with the adhesive coated surface ii of the front wall 2 of the bag top, as will be understood by reference to Figures 1, 6, '7 and 12A, after which heat and pressure is applied to the overfolded bag top walls to thereby cause the thermo-plastic adhesive to become reactivated and thereby bond together the has top walls to hermetically seal the bag mouth.

In Figures 6 and '7 the flap l4 and projecting top ends I of the intucked edge walls are shown folded along the top edge of the front wall 2 (line H), but, if desired, the bag top walls may be transversely folded along a fold line b-b, spaced downwardly from the upper edge of the front wall 2, as clearly illustrated in Figures 6 and 12-B.

It will be noted by referring to th blank shown in Figure 3, that the transverse severing of the tube to form the tubular bag body blanks is such that the uppermost edge ii of the blank, which constitutes the edge 8 of the closure flap I4 shown in Figure 1, extends beyond the fold lines 9 and II, or in other words, into the edge walls 4-4. By so extending the edge It, when the edge walls are intucked between the front and rear walls of the bag body, as shown in Figures 1 and 2, the portions I! are folded around simultaneously with the intucking of the edgewalls. as perhaps best shown in Figures 6 and '7, and 12-A, and are subsequently folded into bonding engagement with the adhesive coated surfac l5 of the front wall 9, as shown in Figures 7 and 8.

In like manner, the edge portions ll of the upper edge of the blank shown in Figure 3 extend beyond the score lines 8 and i2, whereby a similar result is obtained at the ends of the top edge 5 of the front wall 2, as shown at IS in Figures 6 and 7.

In Figures l3, l4 and 15 there is illustrated a conventional form of bottom, generally known to the trade as an S. O. S., or self-opening square bottom. It will be noted that the. particular manner in which the tube from which the tubular bag body blanks are formed is severed to form the bag blank does not in any way interfere with the subsequent formation of the bag bottom, whether it be an S. O. S., satchel type, or pinch bottom. In other words bag bottoms of above types may be formed in the usual manner and by conventional bottoming machinery or equipment. When making S. O. S. on satchel bottoms, the lower portions of the front and rear walls 2! and 22 are expanded or outwardly folded, as shown in Figure 13, whereby the lower portions 23 of the edge walls are inwardly folded. A suitable adhesive 24 may then be applied to the walls as indicated at 24 in Figure 13, and preferably in sub stantially the pattern illustrated, after which the wall portion 22 is folded inwardly over the edge wall portions 23 along a fold line 25. The wall portion 2| is then folded inwardly over the previously folded wall portions along a. fold line 26, to the position shown in Figure 15, thereby com pleting the formation of the bag bottom.

The bottom of the bag constitutes no part of the present invention and it is therefore deemed unnecessary to further describe the same.

In some instances it may be deemed desirable to fold the top walls transversely on a line spaced downwardly from the upper edg of the front wall 2, as indicated by the line b-b in Figure 6. When the bag top walls are thus folded, an added wall thickness is obtained across the center of the bag top because of the transverse folding of the upper marginal edge portion 5 of the front wall 2, as will be understood by reference to Figure 6. This, however, is not objectionable, and adds somewhat to the strength of the bag closure. By cutting the tubular blank ends as herein disclosed, the flap ll may be formed without waste, as will be understood by reference to the drawings.

In the drawings I have shown the invention applied to bags in which th walls are of single ply. Obviously, the invention may be applied to multiwall bags with equal results, as will readily be understood.

It will be apparent to those skilled in the art that I have accomplished at least th principal objects of my invention, and it will also be apparent to those skilled in the art that the embodiments herein described may be variously changed and modified Without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodiments are illustrative only, and that my invention is not limited thereto.

I claim as my invention:

A collapsed gusset bag wherein the top of the bag is composed of front, rear and edge walls and wherein the edge walls are intucked between the front and rear walls, the upper marginal edge portion of the rear wall projecting above the top edge of the front wall to provide an integral closure flap, and the upper ends of the intucked edge walls being disposed at an elevation between the upper edges of the front and rear walls and having substantially triangular portions integral with the edges of the rear wall extending up wardly and outwardly to the ends of the top edge of the rear wall flap and similar portions integral with the edges of the front wall extending downwardly and inwardly to the top edge of the front wall each to a point spaced inwardly from the adjacent side edge of the front wall, said top portion of said collapsed bag having a trans verse fold line adjacent to but spaced downwardly from the top edge of said front wall, said front wall having a transverse strip of adhesive extending entirely across said front wall downwardly from said folded line, said adhesive securing said closure flap when said top position of said collapsed bag is folded on said transverse fold line.

ARTHUR E. SCHENCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,015,007 Cutler Jan. 16, 1912 1,920,322 Rosmait Aug. 1, 1933 2,000,345 Miller May '7, 1935 2,274,934 Piazze Mar. 3, 1942 2,294,848 Moore Sept. 1, 1942 2,345,434 Sterling Mar. 28, 1944 2,370,680 Moore Mar. 6, 1945