GB2042469A

GB2042469A - Flexible skips

Info

Publication number: GB2042469A
Application number: GB7934010A
Authority: GB
Original assignee: Toyama Industry Co Ltd
Current assignee: Toyama Industry Co Ltd
Priority date: 1979-02-23
Filing date: 1979-10-01
Publication date: 1980-09-24
Also published as: DE2949504A1; GB2042469B

Abstract

A flexible skip comprises a body (1), a bottom end piece (2) a filling spout (1c) formed integrally with the body, and a pair of left and right projecting portions (3a, 3b) formed on either side of the spout and sewn together to form a hanging sling (4). The skips are produced by providing a tubular part having an upper portion corresponding to the spout and having symmetric parts 3a, 3b located on the left and right sides of said upper portion which form a hanging sling for the bag. A bottom end 2 is then sewn to the bottom edge of the tubular part to form a bottom for the bag, and superimposed edges 6a, 6b of the symmetric parts are sewn to form a top end with a cylindrical opening. <IMAGE>

Description

SPECIFICATION Bag and process for manufacturing the same The present invention relates to bags for use in storing and transporting bulk materials such as free-flowing powders and granules, particularly a bag having an opening formed in the top portion thereof, and the present invention also relates to a process for manufacturing such a bag.

In known bags having an opening for filling a material, formed in the top portion thereof, the material-filling opening and the top end cover are separately prepared and sewn together, and the top end cover is then sewn to the bag proper. Accordingly, the sewing operation is very troublesome and the efficiency of the sewing operation is very low.

The top end cover is sewn to the bag proper along the entire length thereof to form a seam. This seam can be broken or loosened by an impact or shock occurring during the loading operation. Accordingly, from the viewpoint of safety, it has been desired to improve the quality of these bags.

In accordance with the present invention, there is provided, a bag comprising a bag proper, a bottom end defining the bottom portion of the bag proper, a top end closing the top end portion of the bag proper and an opening formed in the central portion of the top end integrally therewith, wherein a pair of left and right top ends are formed on each side of the opening and are sewn together to form a hanging sling.

In another aspect the present invention provides a process for manufacturing bags which comprise the steps of forming a cylindrical bag proper having in the upper portion thereof a part to be formed into a top end, said part to be formed into the top end being divided into two flaps to be formed into an opening and a pair of flaps to be formed into a pair of projecting portions on either side symmetrically with each other with respect to the central axis of the opening, closing the bottom portion of the cylindrical bag proper, superimposing said two flaps to be formed into the top end, sewing the so formed superimposed edges on both the sides of the longitudinal central axis of the bag proper, and superimposing corresponding edges of said paired flaps along said notices and sewing said superimposed edges to form a pair of projecting portions.

This process for manufacturing bags may be applied not only to the case where a sheetlike fabric material is used as the fabric, but also to the case where a tubular woven fabric formed by a circular loom or the like is used as the fabric.

The invention will now be described by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a perspective photograph showing one embodiment of the present invention, which bag is filled with a granular material.

Figure 2 is an exploded development of the bag is formed from one sheet of fabric, while the bottom end constituting the bottom of the bag and the portion reinforcing the hanging sling formed in the upper portion are removed.

Figure 2 is a perspective view showing the state in which the longitudinal edges of a single piece of woven fabric having the same shape and size as those of the sheet fabric shown in Fig. 2 are superimposed and sewn together.

Figure 4 is a perspective view showing a bag formed by sewing a bottom end to the bottom edge of the fabric shown in Fig. 3 and sewing the edges of the upper notches.

Figure 5 is a perspective view showing a bag formed by integrally joining the top end portions on both sides of the central portion corresponding to the opening in bag shown in Fig. 4 to form a hanging sling.

Figure 6 is a perspective view illustrating the state in which a granular material is filled into the bag shown in Fig. 5 and the opening is closed by a string, which corresponds to the photograph shown in Fig. 1.

Figure 7 is a perspective view illustrating a modification of the bag shown in Fig. 5, where tying strings are attached to both sides of the central portion corresponding to the opening, instead of the hanging sling shown in Fig. 5.

Figure 8 is another embodiment of the present invention, which is similar to Fig. 2.

As shown in Figs. 1 and 5, the bag of the present invention comprises a bag proper 1, a bottom end 2 sewn to the bottom edge of the bag proper 1 along a seam 1a, an opening ic formed in the central portion of the top end 1 b which is formed integrally with the bag proper 1 and projecting parts 3a and 3b extending upwardly from the top end cover 1 b with the opening 1 c being interposed therebetween. The top ends of the parts 3a and 3b are sewn together to form a hanging sling 4. A string 5 is attached to the opening 1 c so that after a material has been filled into the bag proper 1, the string 5 is tied to close the opening Ic.

In the above-mentioned bag, the top end 1 b is a continuous part of the fabric material of the bag proper 1 and is sewn and closed by seams 6a and 6b. Since the seams 6a and 6b are located on the inner sides of the projecting parts 3a and 3b constituting the hanging sling 4, even when a granular material is filled into this bag and it is hung up and moved by using the hanging sling 4, the external force is not directly imposed on the seams 6a and 6b. Accordingly, opening of these seams 6a and 6b of the top end cover 1 b or other trouble is not caused by external force at all. Furthermore, the top end 1 b can easily be formed only by sewing the parts 3a and 3b along the seams 6a and 6b, and the bag of the present invention is characterized in that it can be manufactured very simply.

Therefore, a strong and practical bag can be provided at a low manufacturing cost, according to the present invention.

In the foregoing embodiment, the bottom of the bag is constructed of one sheet-like piece.

As is known,. in bags a bottom provided with a discharge opening may be used. Alternately, there may be adopted a method in which the lower edge of the bag proper 1 is divided into two corresponding parts, and they are superimposed together and sewn together along the superimposed edges to form a closed bottom of the bag proper 1.

The embodiment shown in Fig. 7 has the same structure as that of the bag shown in Figs. 5 and 6 except for the parts 3a and 3b.

In this embodiment, tying strings 7a and 7b are attached to the projecting parts 3a and 3b, respectively, and after a granular material has been filled in the bag, the opening lc is tied and closed by the string 5 and the tying strings 7a and 7b are tied to form a hanging sling of the bag.

The process for manufacturing the bag of the present invention from one sheet-like fabric material will now be described.

As will be apparent from the description given hereinafter, the bag of the present invention can be manufactured very easily according to the following steps.

(a) A rectangular fabric 8 comprising two units of rectangular fabric 8a and 8b having the same size and shape and being symmetrical with each other with respect to the line X is formed as shown in Fig. 2. In the upper portion of the fabric 8, four notches 9a, 9b, 9c and 9d extending to an imaginary line Z parallel to the bottom edge X3 of the fabric 8 are formed so that the portions 1 Oa, lOb, 1 Oc and 1 Od above the imaginary line Z satisfy the following requirements; the portions 1 Oa and lOb should be symmetrical with each other with respect to the longitudinal central line Ya of the unit of fabric designated 8a and the portions 1 Oc and 1 Od should be symmetrical with each other with respect to the longitudinal central line Yb of the unit of fabric designated 8b.

(b) Then, the left edge and the right, designated X2 edge of the fabric 8 shown in Fig. 2 are superimposed together and sewn along a seam 11 to form a cylindrical bag shown in Fig. 3.

(c) A bottom end 1 3 is sewn to the bottom edge X3 of the cylindrical bag 8c along a seam 1 2 to form a bottom portion of the bag.

Instead of the above-mentioned method using the bottom end 13, there may be adopted a method in which the edge X3 is divided in two equal parts and then superimposed and sewn together.

(d) Rectangular projections 1 4a and 1 4b formed on the imaginary line Z and including rectangular portions symmetrical with each other with respect to the central lines Ya and Yb, respectively, are superimposed and a pair of left and right longitudinal superimposed edges thus formed are sewn along seams 6a and 6b, respectively, to form a portion corresponding to a cylindrical opening lc (see Figs. 1, 5 and 6). Then, the corresponding edges of the notches 9c and 9b are superimposed together and the corresponding edges of the notches 9a and 9b are superimposed together, and the superimposed edges are sewn together along the seams 6a and 6b, whereby an intermediate product of the bag, shown in Fig. 4, is made. In this intermediate product, as shown in Fig. 4, three cylindrical falp portions are formed in the upper portion.

A pair of the flaps located on either side is formed into projecting parts 3a and 3b, and the central flap is formed into an opening 1 c.

(e) The top ends of th parts 3a and 3b are connected together through a connecting cloth 4a, and the connecting portion is sewn and tightly joined to form a hanging sling 4a.

A tying string 5 is attached to the materialfilling opening lc. Thus, a bag shown in Fig.

5 is made.

(f) Instead of the above-mentioned method in which the parts 3a and 3b are connected together, there may be adopted a method in which, as shown in Fig. 7, tying strings 7a and 7b are sewn to the parts 3a and 3b, respectively. In this case, there can be manufactured a bag in which a material can be filled more easily than in the above-mentioned bag.

In the so manufactured bag, since the seams 6a and 6b are located on the inner sides, the force imposed on the seams 6a and 6b when the filled bag is transported is very slight, and breakage of these seams 6a and 6b rarely occurs.

As will be apparent from the above-mentioned manufacturing process steps, although the structure of the upper portion of the bag of the present invention is relatively complicated, the cutting and sewing steps can be accomplished very easily and simply. This is one of the important features of the present invention.

The above-mentioned process for manufacturing the bag of the present invention is applied to the case where one sheet-iike starting fabric is cut and sewn. The manufacturing process steps can be further simplified when a tubular woven fabric formed by a circular loom or the like is used as the starting fabric.

In this case, the following step (g) is adopted instead of the above-mentioned steps (a) and (b).

(g) A tubular woven fabric having the same circumferential dimension as that of the intended bag is cut into the same length as that of the starting fabric shown in Fig. 2 and it is flattened so that two sheet-like material pieces are superimposed on each other. Then, notches similar to notches 9a, 9b, 9c and 9d formed on two fabric units 8a and 8b as shown in Fig. 2 are formed. By this operation, an intermediate product of the bag, as shown in Fig. 3, is made. Then, this intermediate product is subjected to the same sewing steps as described hereinbefore, and the intended bag is made.

In the bag having the above-mentioned structure, seams in the vicinity of the materialfilling opening 1 are rarely broken while the bag is actually used in the filled state. However, in order to reinforce these seams, it is preferred that the notches 9a, 9b, 9c and 9d be formed to have a stepped shape as shown in Fig. 8. In fact, by experiments, it was confirmed that a very high reinforcing effect can be attained by this arrangement. Referring to Fig. 8, the inclined portion of each notch includes two inclined parts 15 and 1 7 and a horizontal step 1 6 interposed therebetween.If the inclined portion of each notch is not linearly inclined but a horizontal step 1 6 is formed in the midway, even when a load is imposed on seams (corresponding to seams 6a and 6b in the above-mentioned embodiment) while the bag is actually being used, the load is dispersed at the horizontal step 6 and therefore, the resistance to the load is increased. Therefore, even if the bag made of the sheet shown in Fig. 8 is hung with a hanging sling under an unbalanced condition, the lowest ends 1 8 of the notches 9a, 9b, 9c, and 9d can be prevented from tearing.

The fabric of the embodiment shown in Fig.

8 is the same as that shown in Fig. 2 except for the above-mentioned special configuration of each notch. Accordingly, explanations of the fabric and the steps of sewing the fabric are omitted.

Alternatively, in stead of the above-mentioned horizontal steps 16, short cuts can be made which cuts are positioned in a place corresponding to the horizontal step 16. In this case; seams 6a and 6b are formed around the edges of the notches 9a, 9b, 9c and 9d and the short cuts. The resultant oneway bag has the same function as that of the bag from the fabric in Fig. 8.

As will be apparent from the above illustration, the bag of the present invention is very excellent in its function S, and furthermore, it can be manufactured very easily and simply.

Therefore, the bag of the present invention is very valuable for storing and transporting bulk materials.

From the economical viewpoint, a woven fabric formed by using flat yarns of a polyolefin, such as polyethylene or polypropylene, as warps and wefts is preferably employed as the starting fabric. Of oourse, woven fabrics formed by using other synthetic fiber yarns or natural hemp yarns as warps and wefts can be used in the present invention.

As will be apparent to those skilled in the art, various modifications can be made to the above-mentioned preferred embodiments of the bag of the present invention, based on the basic technical concept of the present invention.

Claims

1. A bag comprising a bag proper having an opening formed in a top end and a hanging sling portion formed on the upper portion of the bag proper, said top end including a cylindrical portion having the opening formed in the central part thereof and projecting portions formed symmetrically on either side of the cylindrical portion, said projecting portions being closed on the inner sides thereof along seams passing through the central axis of said cylindrical portion, and said seams being extended from both the projecting portions to the edge of the opening of said cylindrical portion and cloth flaps constituting the cylindrical portion and being connected to the bag proper being sewn along said seams at positions symmetrical with each other with respect to the central axis of the cylindrical portion.

2. A bag as set forth in claim 1 wherein a tying string is attached to the cylindrical portion.

3. A bag as set forth in claim 1 or 2 wherein both the projecting portions are connected together by sewing.

4. A gas as set forth in claim 1, 2 or 3 wherein tying strings are attached to both the projecting portions respectively, to extend both the projecting portions.

5. A bag as set forth in any of the preceding claims wherein a step is formed on each of the seams on the inner sides of both the projecting portions.

6. A bag as set forth in any of the preceding claims which is composed of a starting woven fabric formed by using polyolefin type flat yarns as warps and wefts.

7. A process for manufacturing bags which comprises the steps of forming a cylindrical bag proper having in the upper portion thereof a part to be formed into a top end, said part to be formed into the top end being divided into two flaps to be formed into an opening and a pair of flaps to be formed into a pair of projecting portions on either side symmetrically with each other with respect to the central axis of the opening, closing the bottom portion of the cylindrical bag proper, superimposing said two flaps to be formed into the top end, sewing the so formed superimposed edges on both the sides of the longitudinal central axis of the bag proper, and superimposing corresponding edges of said paired flaps along said notches and sewing said superimposed edges to form a pair of projecting portions.

8. A process for manufacturing bags according to claim 7 wherein said cylindrical bag proper is made by forming one sheet-like starting fabric by cutting and superimposing and sewing both the edges of the main portion of the fabric to be formed into the bag proper.

9. A process for manufacturing bags according to claim 7 wherein said cylindrical bag proper is made by cutting a tubular woven fabric.

10. A process for manufacturing bags according to claim 7 wherein the bottom of the cylindrical bag proper is formed by sewing the bottom edge of the cylindrical bag proper to a bottom end piece.

11. A process for manufacturing bags according to claim 7 wherein the bottom of said cylindrical bag proper is closed by dividing the bottom edge of said cylindrical bag proper into two equal parts and superimposing and sewing these equal parts to each other.

1 2. A process for manufacturing bags according to claim 7 wherein each of said notches has a step in the midway thereof.

13. A process for manufacturing bags according to claim 7 wherein to top ends of both the projecting portions.

14. A process for manufacturing bags according to claim 7 wherein tying strings are sewn to the top ends of both the projecting portions, respectively, to extend said projecting portions.

1 5. A process for manufacturing bags substantially is hereinbefore described with reference to the accompanying drawings.

1 6. A bag when manufactured by a process according to any of claims 7 to

15.

1 7. A bag substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.