US1981711A - Paper sack - Google Patents

Description

J. RUSSELL Nov. 2 0, 1934.

PAPER s ck Filed May 12, 1955 Patented Nov. 20, 1934 res UNITED STA PAPER SACK John Russell, Sydn y,

Austr New South wales. alla Application May 12, 1933, Serial No. 610,766

In Australia May 27, 1932 9 Claims.

This invention relates to multiply paper sacks and it has been devised (inter alia) to adapt such sacks for gravity filling and for subsequent closure by the packer, by sewing or stapling.

Multiply paper sacks are sacks adapted for containing trade quantities of cement, grain, or other powdered or granular material, and are constructed of a plurality of plies of strong flexible paper tubed and closely nested, thereby to ensure mutual resistance by the plies to oppose bursting stresses to which these sacks are subjected in use.

Open mouth sacks constructed of woven material are used for many products, and such sacks when filled are readily closed by sewing extending across their top ends.

Multiply paper sacks supplied to the packer with their top ends open have presented great difficulty to closure by the packer as they-can be closed by sewing or stapling only with great inconvenience and with risk-of insecurity, because the plies and folds frequently become rucked and displaced in drawing them over the contents of the sack for closure by the sewing machine or the stapling tool; the sewing or stapling operation then becomes awkward; torn, unsightly and insecure packages result.

In the known art of multiply paper sack manufacture preclosure of the top end of the sack in manufacture is efiected by a line of machine sewing which is usually passed through a binder strip which is lapped over the lips of the mouth, and filling is effected by gravity through an aperture formed for such purpose in the sack side below this top closure, and this aperture is closed by a fiap or by' a stuck-on cover piece, as described in Commonwealth Patent No. 5274/31. In an older type of multiply paper sack, which, however, is not adapted for gravity filling, the filling aperture is a valve formed in a bellows fold in the side edge of the sack adjacent the top and closure seam.

In multiply paper sacks according to the present invention, the top end of the sack is closed, this end is lapped with a binder strip, and the closing seam is sewn through the binder strip in the manufacture of .the sack. The filling aperture is provided by slitting or forming an elongate notch on one wall of the sack crosswise,'imme- :liately below the line of the closing seam just mentioned and within the area which is covered by the skirt of the binderstrip. elongate notch iscut before the top end of the sack is closed. After the sack has been filled by the packer, sealing of the filling aperture is effected by running another line vof -sewing (or This slit or may be stapling) parallel with and near to the manufacturer's or factory closing seam befor'e-, mentioned; this other line of sewing or stapling passes through the skirt portion of the binder -'.strip and through both walls of the sack below the filling aperture; the filling aperture thus sealed lies between the factory closure line of sewing or stapling and the packers line of sew-. ing or stapling which is below it.

A sack according to this invention is easily manufactured, is readily fil lable by the packer using a gravity spout, and because the lips of the top end of the sack are held together flatly by the factory closure sewing, they do not tend to ruck or crumble so as to cause difficulty in the-application of the packers line of sewing or stapling 'which is applied by the packer after the 4 sack is distended by its contents.

, In order to guard against entry into the interply spaces of particles of the, material which is being packed, the exposed edges of the paper plies at the underside of the slit or elongate notch may be cemented together. The cementing should not be extended much below the slit edges as its purpose isonly to hold the edges together though incidentally this cementing operatesto offer some additional strength to the packers closure.

In practice a binder strip would always be used vto lap the end of the sack and serve as reinforcement'for the closure lines of sewing or stapling, but the invention may be used with diminished utility without a binder strip. It is .to be understood that the inventio is not limited to forms of sack construction in which a binder strip is used.

In order to provide uniform thickness in the plies of paper through which the top end factory closure sewing passes, the filler aperture in the sack side is formed by a crosswise slit through the plies in one side of the sack, and the marginal paper above the slit is left in situ. But, the paper ply margin above the filler slit may be cut away so as to leave an elongate notch in the top edge of the sack side; in this case the factory closure sewing will miss one sideof the sack where the notch is cut out of it. In both casesthe packers closure line of sewing or stapling will pass through both sides of the sack below the filler aperture level.

This invention provides a novel .method of packaging materials of the kind hereinbefor' referred to, consisting in providing a multiply paper sack having its top end closed by uniting its walls by a crosswise seam and optionally reinforced in this seam, and having an elongate aperture less in length than the width of the sack formed in one side of it close below said seam and substantially parallel thereto, introducing said materials into the sack through said aperture, and thereafter uniting the sack walls by a sewn or stapled seam so as to seal off said aperture.

The invention will be best understood by reference to the accompanying drawing, in which:-

Fig. 1 is a perspective view of a sack according to the invention, as it appears when distended and closed by the packer;

Fig. 2 is a fragmentary perspective view showing the upper part of the same sack as it appears during filling whilst the filling aperture in the top end of one of the sides is stretched open and the skirt portion of the binder strip is lifted up to offer clearance for a depending filling spout (not shown) through which gravity filling of the sack is effected;

Fig. 3 is an enlarged perspective .view of the top end of the sack showing the parts of the plies on one side of it above the filling aperture notched out before the top end of the sack is closed at the factory; the section is considerably exaggerated in order to disclose clearly the bellows folds at the side edges between the respective sides of the sack and the notching out of the top portion of one of the sides of the sack to provide the filling aperature;

Fig. 4 isa fragmentary perspective sectional view showing the loose skirt of the binder strip as it appears when the sack leaves the factory and before the sack is filled; and

Fig. 5 is a similar view showing the factory closure and also the packers closure sewing line. Both lines of sewing pass through both flaps of the binder strip and through both sides of the sack below the slit or elongate notch in one of the sack sides seen in Fig. 2 and in Fig. 3.

The sack is constructed of a plurality of plies of tubed paper of tough flexible nature, following common practice in the art of producing multiply paper sacks. The bottom end of the sack may be closed in any way but is most effectively closed by a line of sewing B passed through both walls of the sack and through a binder strip C folded over the sack end. The binder strip C is a little longer than the width of the sack and extends beyond the sack walls, providing short lugs D through which the sewing is continued to ensure security against loosening of the stitches which pass through the sack sides. This method of bottom end closure is in common use. The present invention is not concerned with the means for closing the bottom end of the sack; it is concerned only with the mouthing of the sack and with mouth closure means at the top end of the sack.

The nested tubed plies of paper are assembled with re-entrant bellows side folds E-E in the usual way, as seen in Fig. 3. Midway of its width one side F of the sack is notched out for an appropriate length for accommodating a filler spout,

as shown at G, Fig. 3. Notching is not essential.

It suffices if a crosswise slit of appropriate length is cut in the sack side at the notch level G, Fig. 3 as seen in Fig. 2; in that case the margin part of the sackside above the slit is retained and is held by the factory closure sewing line H; it is advantageous, for the reason that it maintains uniform for the whole length of the seam the thickness of material through which the factory stitches pass. A binder strip L, preferably constructed of tough crinkled paper, is folded over the mouth of the sack as seen in Fig. 4, and the factory line of top end closure sewing H is passed through both skirts J and K of the binder strip L and the embraced ends of the paper plies; this line of sewing secures the two sides F and M of the sack together without obstructing the slitted or notched-out portion G of the sack side F. Thesack top end thus closed at the factory is seen in Fig. 2, Where the binder flap skirt K which overhangsthe slitted side F of the sack is shown lifted up and the sack side F bulged outward below it to expose the filling aperture N through which a vertical drop spout can be entered into the sack to fill it. 1

It is usual practice in the manufacture of multiply paper sacks to dispose the pasted longitudinal seams of the several paper tubes at one side of the sack but not in register one over the other, as shown by full and dotted lines X in Fig. 3. It is preferred to cut the mouth slit or notch in that side of the sack in which these longitudinal seams are located, as the wall is stouter at that side of the sack by reason of the lapping and pasting together of the paper edges, and consequently risk of tearing at the mouth is reduced.

It is desirable but not essential that the edges of the paper plies at the mouth slit or notch should be pasted together at the facory in order to closethe interply spaces and prevent accidental passing of loading material into those spaces, for which object the plies should be held closely each one in contact with the neighboring ply or plies.

The pasting together of the ply edges at the mouth slit or notch serves also the purpose of holding them compactly in register to receive the packers line of closure sewing or stapling P which is made by the packer after the sack has been filled. The edge pasting also minimizes risk of tearing, stretching, or mutilating the ply edges at the filling aperture by awkward manipulation of the filling spout, and it operates generally to reinforce the sack in the locality of the filler mouth so that risk of failure of the sack in that locality by rough usage is minimized.

Whilst in practice the packers closure seam P is a straight seam extending the full length of the binder strip L, this seam need not necessarily extend for the full width of the sack. It would sufllce if it extended only a distance a little more than the length of the filling aperture and be brought up clear outside each end of that aperture across the'binder strip so as to prevent leakage of loading at the ends of the filling aperture, as shown by the dotted line Z in Fig. 5.

Sewing is a more advantageous method than stapling for making the sack end seam at the factory and for making the packers closure seam, but stapling is quite practicable and effective.

One of the advantages of this type of closure over known cases is that it provides adequately for completely closing and sealing the sack by machine sewing. By means of the factory closure sewing the top end of the sack is collapsed and held quite fiat to receive the packers sewing or stapling. The filling aperture is completely surrounded .by fixed portions of the sack which constantly urge the collapsing of the bulged-out lip of the filling aperture. The filling aperture is in one side only of the sack, and there is only one edge to be collapsed, and as the other wall is, so to speak, a fixture, this collapsing can be readily accomplished.

Another advantage is the fact that the sack end in manufacture can be sewed in the usual way without requiring any provision for interruption of stitch lines or removal of stitches to expose the of the sack with the nonapertured side of it close below said aperture after the sack has been filled. 2. A multiply paper sack having its top end partly closed by a seam reinforced by a binder strip lapped over the end of .the sack, and having a filling aperture formed in one side of said sack substantially parallel with and immediately below said seam and within the area covered by the skirt of said binder strip, said aperture sealed by another seam passing through the skirts of the binder strip and uniting the apertured side of the sack with the non-apertured side of it close below said aperture after the sack has been filled. v e

3. A multiply paper sack having its top end partly closed by a seam and having a filling aperture formed in one side of it parallel with and immediately below said seam, said aperture adapted to be sealed by another seam uniting the apertured side of the sack with the non-apertured side close below said aperture after the sack has been filled,

4. A multiply paper sack having its topend partly closed by a seam reinforced by a binder strip lapped over the end of the sack and having a filling aperture formed in one side of it substantially parallel with and immediately below said seam and within the area covered by the skirt of said binder strip, said aperture adapted to be sealed by another seam passing through the skirts of the binder strip and uniting the apertured side of the sack with the non apertured side of it close below said aperture after the sack has been filled.

5. A multiply paper sack having a closure at each end of it, afilling aperture in one side of said sack near to and substantially parallel with one of said closures, and a seam through said sack binding its opposite walls together below and adapted to seal said filling aperture after the sack is filled.

6. A multiply paper sack having at its top end a seam and having a filling aperture formed in one side of it parallel with and immediately below said seam, said aperture adapted to be sealed by another seam uniting-the apertured side of. the sack with the non-apertured side below and about the ends of said aperture after the sack has been filled.

7. A multiply paper sack having its top end partly closed by a' seam reinforced by a binder strip lapped over the end of.the sack and having a filling aperture formed in one sided it substantially parallel with and immediately below said seam and within the area covered by the skirt of said binder strip,s aid aperture adapted to be sealed by another seam passing through the skirts of the binder strip and uniting the apertured side of the sack with the non-apertured side of it below and about the ends of said aperture after the sack has been filled.

8. A' filled multiply paper sack having its top end partly closed by a seam and having a filling,

aperture formed in one side of it parallel with and immediately below said seam, said aperture sealed by another seam uniting the apertured side of the sack with the non-apertured side below and about the ends of said aperture after the sack has been filled. i

9. A filled multiply paper sack having its top ends partly closed by a sewn seam'reinforced by a binder strip lapped over the end of the sack and having a filling aperture formed in one side of it substantially parallel with and immediately below said seam and within the area covered by the skirt of said binder strip, said aperture sealed by another sewn seam passing through the skirts of the binder strip and uniting the apertured side of the sack with the non-apertured side of it below and about the ends of said aperture after the sack has been filled. v

. t JOHN RUSSELL.

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