US2830750A - Bag - Google Patents

Description

April 1958 A. N. WEEKS ETAL 2,830,750

BAG

2 Sheets-Sheet 1 Filed Dec; 25, 1954 April 1958 A. N. WEEKS ET AL 2,830,750

BAG

Filed Dec. 2:5, 1954 2 Sheets-Sheet 2 BAG Arnold N. Weeks, Cohasset, and Lige Coakley, Pepperell, Mass, assignors to Bemis Bro. Bag Company, St. Louis, Mo., a corporation of Missouri Application December 23, 1954, Serial No. 477,156

2 Claims. (Cl. 229-625) This invention relates to bags, and more particularly to a pasted valve bag of a type used for packaging finely divided material, such as Portland cement, the bag being filled by inserting a filling spout in the valve and blowing ghe finely divided material through the spout into the Prior pasted valve bags of the class described have been objectionable in that the contruction of the bag end closure at the corner of the bag opposite the valve has been such that finely divided material is blown in between folds of the closure at the stated corner of the bag during the filling of the bag. Among the several objects of this invention may be noted the provision of a pasted valve bag having an improved closure construction at the corner of the bag opposite the valve which is effectively sealed against entry of material between folds of the closure, and the provision of such a closure construction which is economical to manufacture. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. 1 is a view in elevation of a bag tube irorn which a bag of this invention is made, the central part of the tube being broken away;

Fig. 2 is a view of the upper portion of Fig. 1 illustrating the formation of a closure of this invention at the valve end of the bag;

Fig. 3 is a View corresponding to Fig. 2 showing the completed closure;

Fig. 4 is an enlarged cross section of the closure as it appears when turned into a plane at right angles to the plane of Fig. 3 and when the bag is spread open, being taken on line 4-4 of Fig. 3;

Figs. 5, 6 and 7 are cross sections taken respectively on lines 55, 6-6 and 77 of Fig. 4; and,

Fig. 8 is a plan showing a mode of forming bag tubes as illustrated in Fig. 1.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, Fig. 1 shows a flat paper bag tube 1 from which a bag of this invention is made. This tube is usually a multi-ply tube, and appears as such in Figs. 4-7. it will be understood, however, that the principles of the invention are equally applicable to a single-ply tube. In the case of a multi-ply tube, it will be understood that the plies are conventionally pasted together at the ends of the tube to prevent sifting of finely divided material between the plies. The side folds of the flat tube 1, which constitute its side edges, are designated 3 and 5. As herein illustrated, a valve is to be provided .nited States Patent 0 the plies of the tube. This extension is centrally folded on a fold which is an extension of the left side fold 3 of the tube. When unfolded fiat, the extension 7 has a total width W (see Fig. 2) corresponding to the width of the end closure which is to be formed at the upper end of the tube 1.

It will be understood that bag tubes such as the tube 1 shown in Fig. l are manufactured in commercial production by segmenting a continuous length of bag tubing into individual tubes 1. One way of providing an extension 7 on each of the tubes 1 segmented from the continuous length of tubing is to cut the material for the extension 7 of any given tube 1 out of the adjacent end of the adjacent tube segmented from the continuous length of tubing. This leaves a cut-out 9 at the other end of the tube from the end with the extension 7 (see Fig. l).

The bag tube 1 is provided with pasted closures at both ends. This invention is concerned only with the closure at the valve end of the bag tube, which is its upper end as shown in Fig. l. The closure at the other end of the tube is a conventional diamond fold closure, for example, and hence will not be particularly described. As shown in Fig. 1, the tube 1 is provided with longitudinal slits 11 at its upper end, these slits defining end flaps 13 and 15, and first and second side flaps 17 and 19. The tube is shown as having a central notch 21 in one Wall at its upper end, this notch being in the side flap 17. The end flap 13 incluudes the centrally located inwardly directed extension 7, the extension being narrower than the inner end edge of the end flap 13.

in forming the closure at the valve end of the bag tube, the side flap 17 is folded back upon the tube upon a fold line 23 extending transversely with respect to the length of the tube. This operation effects turning in of the flaps 13 and 15, these flaps folding on lines indicated at 25 extending from the side edges of the tube to the inner ends of the slits 11. Upon turning in the flap 13, the extension 7 is opened and spread fiat. Adhesive (paste), designated A, is then applied in the pattern shown in Fig. 2, the pattern consisting of a stripe of adhesive extending transversely across the side flap i9 and a stripe extending in lengthwise direction with respect to the tube from side flap 19 and over the inner end of the end flap 13 and the extension 7 to the side flap 17. The side flap 17 is then folded over upon a transverse fold line 2'7 to overlie the end iiaps 13 and 15. To complete the formation of the closure, the side flap 19 is then folded over upon a transverse fold line 29 to overlap the flap 17. Fold line 27' is coincident with one side edge 31 of the extension 7; fold line 2.9 is coincident with the other side edge 33 of the extension 7. Portions 13a and 15a of the end flaps 13 and 15 lying outward of line 27 are folded over with and included in side fiap 17; portions 13b and 15b of the end flaps lying outward of line 29 are folded over with and included in side flap 39.

As a result of the above operations, the side flap 17 becomes adhered to the end flap 13 (and to the extension 7 of the end flap 13). It does not, however, become adhered to the end flap 15. The side flap 19 becomes adhered to the side flap 17. The completed closure cornprises the inwardly directed end flaps 13 and 15 and the side flaps 17 and 19 folded over on the transverse fold lines 27 and 29 to overlap one another and to overlie the end flaps. The side flaps 17 and 19 are adhered together by the stripe of paste initially applied to extend transversely across the flap 1?. The adhered-together side flaps 17 and 19 are free of the end flap 15 to provide a valve capable of accepting a filling spout inserted as indicated by the arrow in Fig. 4. The extension 7 is adhered across its entire width to the inside face of the closure portion formed by the adhered-together overlapping side flaps 17 and 19. This provides a seal effectively preventing material blown into the bag through a filling spout from being blown into the pockets such as indicated at 34 and 35 in Fig. 4 between portion 13a of end flap 13 and side flap 17 and between portion 13b of end flap 13 and side flap 19. It is essential that extension 7 be made as wide as but no wider than the closure width (i. e., the distance between fold lines 27 and 2.9) otherwise these pockets will not be effectively sealed against entry of material.

Fig. 8 shows another way of manufacturing bag tubes 1 such as shown in Fig. 1, also involving segmenting a continuous length of bag tubing indicated at T into individual tubes 1. In this case short longitudinal cuts 37 having a length corresponding to the length of extension 7 are made adjacent side edge 3 of the tubing at bag length intervals. Then the tubing is segmented into individual tubes 1 by making transverse cuts 39 completely across the tubing, eachcut 39 intersecting one end of a longitudinal cut 37, and by making transverse cuts 41 extending from the other ends of the longitudinal cuts 37 to the side edge 5 of the tubing. This cuts out portions 43 of the tubing, which fall away as waste.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. A bag having a closure at one end comprising inwardly directed end flaps, one of said end flaps having a centrally located inwardly directed extension at its inner end narrower than the inner end edge of said one end flap, a first side flap folded over on a transverse line coincident with one side edge of the extension and overlying the end flaps, and a second side flap folded over on a transverse line coincident with the other side edge of the extension and overlying said first side flap and the end flaps, said extension thereby being as wide as but no wider than the distance between said transverse lines, portions of said end flaps lying outward of said transverse lines being folded over with said side flaps and included in said side flaps, said side flaps being adhered together, and said extension being adhered across its entire width to the adhered-together side flaps, said side fiaps being free of the other end flap to provide a valve.

2. A multi-ply paper bag having a closure at one end comprising inwardlydirected end flaps, one of said end flaps having an integral extension of all of the bag plies 2:1 i ts inner end, said extension being narrower than the inner end edge of said one end flap and centrally located with respect to said inner end edge, a first side flap folded over on a transverse line coincident with one side edge of the extension and overlying the end flaps, and a secand side flap folded over on a transverse line coincident with the other side edge of the extension and overlying said first side flap and the end flaps, said extension thereby being as wide as but no wider than the distance between said transverse lines, portions of said end flaps lying outward of said transverse lines being folded over with said side flaps and included in said side flaps, said side flaps being adhered together and adhered to said one end flap with said extension adhered across its entire width to the adhered-together side flaps, said side flaps being free of the other end flap to provide a valve.

References Cited in the file of this patent UNITED STATES PATENTS 1,827,040 Redington Oct. 13, 1931 2,102,766 Tooker Dec. 21, 1937 2,176,499 Hoppe et al. Oct. 17, 1939 2,346,292 Coty Apr. 11, 1944

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