US2605040A - Bag construction - Google Patents

Description

July 29, 1952 D. BELCHER 2,605,040

' BAG CONSTRUCTION 7 Filed April 12, 1948 2 SHEETS-SHEET 1 y 29, 1952 D. BELCHER 2,605,040

BAG CONSTRUCTION Filed April 12, 1948 2 SHEETS-SHEET 2 Patented July 29, 1952 2,605,040 BAG, CONSTRUCTION Daniel Belcher, Minneapolis,,Minn., assignor to ,Be'mis-Broi Bag 00., Minneapolis, Minn., a corporation of Missouri Application April 12, 1948, Serial No. 20,490

1 My invention relates generally to the bag-makin'g art and, more specifically, to the maling of bags from material which is' normally so flimsy or sleazy as to be incapableofcooperatingwith well-known bag closure mechanism to provide a proper closure'ther'efor. I 1

Cellophane is" a typical example of suchma terial'.-' Cellophane and like sheet materials'are ideally suited for the packagingof commodities because they have considerable tensile" strength and ,yet are thin and transparent: However, in the mechanical packaging of goods in bags formed from such sleazy or flimsy materials, and more particularly in providing adequate closures by mechanical means for such bags, certain well-' recognized problems have confronted the industry. A conventional bag is initially formed into a tube fromflat sheet material. Thereafter, the bottom of the bae is closed in any suitable manhen-approximatelyone-quarter of the length of thetube being utilized for thispurpose. Approximately'two-thirds of this closed-bottom bag is utilized for the contents or fill andthe remaining one-third, adjacent the open top; is utilized to provide an adequate top closure. Such top 010- sur'es are made'mechanically, an example of such mechanism and a method-of closing such-abag being illustrated'in BelcherPatents 1;868,686 and 1,989,471; I

A single sheet of thin cellophane isso lacking in rigidity that'itwillcollapse under the pres-' sure'of mechanical closure mechanism! This may also be true of two or more sheets or plies adhered together. It is in attempting to mechanically close" bags formed from one or two sheets of cellophane (or any other material having similar characteristics) and after the contents or fill have been placed in the open-topped bag, that the particular problem with which we are here confronted arises. In other words, unless the unsupported approximately one-third of the bag projecting above the fill has c'onsiderablerigidity or body, it will collapse uponcontact with the mechanical closure mechanism, thus rendering closurecby mechanical means impossible. Therefore, in' order to attain sufiicient stiffness-or rigidity for the upp'er'one third of the bag (onequarter of the tube from whiclithe bag is formed), the industry has found it necessary to make the entire bag from cellophane which is heavier than is normally required to carry the contents of the bag. This may be done, either by forming the bag from a single ply of cellophane of sufficient thickness to prevent collapse upon contact with mechanical top-closure mechanism or by form- 3 Claims. (01. 229-53) ing the bag from-two or-more thinner plies'of cellophane, which in the aggregatehave sufiicient rigidity or stability to preventcollapse upon contact with mechanical top-closure mechanism; However, in either event, the cost of producing such bags runs unnecessarily high, in view of the fact that three-quarters of the tube from which the bag. is formed is formed fromth-icker materialthanis'necessary. I v

The primary object rofhmy invention is the provision of a bag; allbut the approximate upper one-third or foldabletop portion thereof being formed of light; sleazy, and inexpensive material of insufficient rigidity to cooperate'with conven-' tional bag closuremech'anism-whe; upper one-. third thereof being ofsuch rigidity as to enable said closure mechanism to successfully operate thereon-and therewith; a

Another object of my invention is to materially reduce the cost of producing bags'=from sleazy material without unduly impairing the quality oi said'bags.- a

The above and still further objects of my invention will become apparent from thefollowing detailed specification,- appended" claims and at tach'eddrawings. I 5

R f rr n to the drawings,*wliereinlikechar acters indicate likeparts throughout the'severa'l iews: l J m Fig. 1- is a-view perspeetiveof a non-gusseted bag having its ii'pper'or' open end stiffened inae cordancewith-my'invention; g

I 2' isa' vi'e'w corresponding-to but showing a gussetecl type of bag; I

Fig. 3 is a view in perspective illustratingthe position which the bag ofFig. assumes when the contents are placed ther'ein, but prior to" pro-'- viding a top closure; e

Fig. 4 is a view corresponding" to" Fig. 3, but showing the bag in; a? partially closed condition;

Fig.- 5 is a fragmentary perspective illustrating the bag of Fig. l'in a totallyIclose'd and; sealed condition; I

Fig. 6 is' aifrag'mentaryviewin elevation, son parts broken away-an some parts shownfi see; ti'oii, illustrating a modification of the stiffening thereof and I 7 '1,

Fig; 7- is-a view.corresponding to (Fig; 6; tin showing a still-further modification time 's'tifiefi ingiappli'e d thereto. f 7 V Referring particularly to Figsjl, 3; 4 and 5 of the drawings, the numeral l indicates, in its entirety, a bag having a tubular body 2 and having a closed bottom 3, which is formed from approximately the bottom one-quarter of the original open-ended tube, from which the bag I is made.

It may be pointed out that no problem arises in the providing of an adequate bottom closure 3 by mechanical means in view of the fact that the tubular material from which the bag is formed is folded flat as indicated in Fig. 1, and is amply supported during the closure operation. Therefore, the thickness or rigidity of the material from which this portion of the tube is formed is of no particular consequence.

While bag I may be formed from one or more piles of material, as shown, it is formed of two plies of material, such as cellophane, and identified by the numerals 4 and 5. It will be observed that the fill portion of the bag I, or that portion set aside for the contents, is approximately two-thirds of the height thereof. The limits of the fill portion are identified by the numerals 8-6 in Fig. 3. The remaining approximately one-third of the closed-bottom bag 1, adjacent the open upper end thereof, is utilized to provide an adequate top closure for said bag. The limits of the foldable upper portion of the tubular body are identified by the numeral l-l' in F g. 3.

When the contents or fill of the bag is placed therein, as indicated in Fig. 3, the tubular body 2 assumes a generally rectangular form. This is true whether the bag is of the type illustrated in Fig. 1, or of the type illustrated in Fig. 2. It should be here pointed out that the rigidity of the material from which the portion 6-8 of the tubularbody 2 is formed is not of any particular importance because of the fact that the fill or contents of the bag support and prevent collapse of that section. Therefore, in bags constructed in accordance with my novel invention, the portion 6-6 may be and is formed from materials which are too light and sleazy to permit bag closure mechanism to properly operate thereupon.

Referring now to that portion of the bag representing approximately one-third of the length of the tubular body 2 above the fill portion 6-6, and identified by the numeral 'I-7, it will be observed that this portion also assumes a generally rectangular cross-sectional shape when the fill or the contents have been placed in the tubular body 2; and I have found that while section 1,! may be formed of material which will maintain itself erect when in such tubular form, nonetheless, it may not have sufficient rigidityto enable a closure to be made mechanically therewith. On the other hand, I have found, if the material forming the portion 'l-l is of, or has imparted thereto sufficient rigidity to prevent total collapse under the action of the mechanical closure mechanism, a mechanically-formed top closure may be successfully made therewith.

The portion 1-'l, being initially identical (insofar as thickness of material, number of plies and the like is concerned) with the bottom 3 and the intermediate portion 6-6 of bag I, will not withstand the forces exerted thereupon by mechanical bag closure mechanism; and I have found that sufficient rigidity to allow mechanical closure mechanism to successfully operate thereon, may be imparted thereto in several different but equally satisfactory ways. For instance, in the structures of Figs. 1 to 5 inclusive, this is accomplished by applying a stiffening adhesive,

in a broadcast manner and without regard to fold lines, between the plies 4 and 5. In the case of a one-ply bag, the reinforcing of portion l-I may be accomplished by applying a stiff drying ink or coloring agent to the entire surface thereof or to a sufiicient portion of the area to create the desired result.

In Fig. 6, the stiffening agent has been applied to the portion l'l by means of diagonally crisscross lines, whereas, in Fig. 7, the stiffening agent has been applied to the area 'l-'I in parallel vertical lines. No regard in either instance is had to fold lines.

The bag of Fig. 2 differs from the bag of Figs. 1, 3, 4, and 5 only in that it is a so-called gusseted type. So far as this invention is concerned, the bag in Fig. 2 is treated as similar in all respects to the bag illustrated in Figs. 1, 3, 4, and 5 and the several parts thereof carry the same marks with prime marks added.

While I have shown several different methods of constructing bags in accordance with my invention, it should be understood that my invention should not be limited to any particular type of bag, to the type of material used, to the number of plies of material used, or to the particular manner of imparting rigidity to the foldable I upper end portion of the bag, except as defined by the appended claims.

I claim: Y

1. A pre-formed collapsed bag having a tubular body open at one end and composed of flimsy transparent plastic material, the top foldable surface areas at the open end of the body being coated with a stiffening adhesive extending downwardly from thetop edge to substantially one-third the length of the bag and terminating at points in a common plane defining the fold line in the formations of an end closure from said stiffened areas, said material rendering said bag self-sustaining in, said top foldable areas, whereby to facilitate the; automatic filling anc closing of bags having flimsy wall structures.

2.' A bag according to claim 1, wherein the stiffened areas are relatively narrow stripes of stiffening material extending inwardly from the open end of the tubular body to said common plane defining the top fold line.

3. A bag according to claim 1, wherein said tubular body is composed of superimposed plies of transparent flimsy plastic material, and said plies being adhered only inwardly from said open end to said common plane by said stiffening adhesive material.

DANIEL BELCHER.

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

V UNITED STATES PATENTS Number Name Date 917,124 Peirson Apr. 6, 1909 2,116,571 Qurwick May 10, 1938 2,158,755 Hodgdon et al. May 16, 1939 2,184,166 Rape Dec. 19, 1939 2,225,389 Osterdahl Dec. 17, 1940 FOREIGN PATENTS Number Country Date 491,682 Great Britain Sept. 7, 1938

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