Flexible large container with a seam-free useful space

Abstract

A flexible large container for transporting and storing a filling product. The container has a usable space formed by top, bottom, and side walls that are constructed from a plurality of fabric sheets. The portions of the fabric sheets that enclose the usable space are welded together to provide a stitchless usable space. Upper portions of the sidewalls extend upward beyond the usable space to form a hem. Lift loops that enable the large container to be lifted by mechanical means are sewn onto the hem. Thus, the usable space remains stitchless, i.e., without stitch holes, yet the lift loops are stitched to the hem.

Claims

1. A flexible large container for receiving bulk material, the flexible large container comprising: a plurality of fabric sheets that are woven with weave fibers and that are assembled together to form a leak-proof stitchless usable space having four sidewalls, a floor, and a cover; a hem that is formed by the four sidewalls, an upper end of these four sidewalls extending upward beyond the cover, such that the hem is above the usable space; a liner that is laminated to sides of the plurality of fabric sheets that face in toward the usable space; a belt that extends circumferentially around the hem; a plurality of lift loops, each lift loop of the plurality of lift loops having a lower end that is U-shaped with the U-shaped end having a first layer and a second layer, the belt sandwiched between the first layer and the second layer, the plurality of lifts loops and the belt stitched to the hem with the stitching extending through the first layer, the belt, and the second layer; the hem having reinforced woven sections wherein the woven fabric where the lift loops attach has a higher density of the weave fibers than a usual density of the weave fibers of the plurality of fabric sheets; wherein stitching the plurality of lifts loops to the reinforced woven sections causes a distribution of a lift load over an entire height of the flexible large container; wherein the liner contains polyethylene; wherein the plurality of fabric sheets contain polyethylene; and wherein the plurality of the fabric sheets that surround the usable space have seam edges and wherein the seam edges of each of two adjacent sheets of the plurality of fabric sheets are overlapped.

2. The flexible large container of claim 1, wherein the plurality of fabric sheets that form the usable space are woven with the weave fibers that are woven in two directions that cross each other and wherein at least the weave fibers of one direction contain polyethylene.

3. The flexible large container of claim 2, wherein the weave fibers are synthetic tapes.

4. The flexible large container of claim 2, wherein the weave fibers are synthetic filaments.

5. The flexible large container of claim 1, wherein the polyethylene is a high density polyethylene.

6. The flexible large container of claim 1, further comprising a corner support, wherein any two adjacent sides of the four sidewalls form a corner area and wherein the corner support is attached to each of the two adjacent sidewalls, so as to extend diagonally across the corner area along a vertical section of the corner area, and wherein the corner support has openings that allow the bulk material to flow into the corner area.

7. The flexible large container of claim 1, further comprising a fill tube that is provided in the cover, wherein the cover and the fill tube are constructed as separate elements, wherein the fill tube is constructed of the same fabric as the cover, and wherein the fill tube and the cover are attached to each other by means of a welded seam.

8. The flexible large container of claim 1, further comprising a discharge tube that is provided in the floor, wherein the floor and the discharge tube are constructed as separate elements, wherein the discharge tube is constructed of the same fabric as the floor, and wherein the discharge tube and the floor are attached to each other by means of a welded seam.

9. The flexible large container of claim 1, wherein the overlapped seam edges are welded together to form a welded seam.

10. The flexible large container of claim 9, wherein an intermediate layer containing polyethylene is placed between the seam edges of the two adjacent sheets and is incorporated into the welded seam.

11. The flexible large container of claim 1, wherein the higher density of the weave fibers is at least twice the usual density of weave fibers in the plurality of fabric sheets.

12. The flexible large container of claim 1, wherein the liner consists of polyethylene and the plurality of fabric sheets consist of polyethylene.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is described with reference to the accompanying drawings, which are purely schematic. In the drawings, like reference numbers indicate identical or functionally similar elements.

(2) FIG. 1 is a perspective view of a flexible large container according to the invention.

(3) FIG. 2 illustrates in detail how a lift loop is attached to a belt.

(4) FIG. 3 is a perspective view onto a horizontally cut flexible large container that is constructed as a dimensionally stable container.

(5) FIG. 4 illustrates a conventional seam for joining two fabric sheets.

(6) FIG. 5 illustrates an overlapping seam.

(7) FIG. 6 illustrates a seam according to FIG. 5, in the transition area from the floor to a sidewall of the large container.

(8) FIG. 7 illustrates a perspective view of the flexible large container with lift loops having an Omega-shape.

DETAILED DESCRIPTION OF THE INVENTION

(9) The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art.

(10) FIG. 1 shows a flexible large container 1 according to the invention, the basic construction comprising sidewalls 2, a cover 3, and a floor 4, all made of a woven fabric. The fabric of the sidewalls 2 extends upward beyond the cover 3, forming a hem 5. Openings, not shown in the figure, may be provided in the hem 5 for drainage purposes. As shown, the large container 1 is rectangular in shape. These large containers 1 are filled with bulk material, such as grains, powdered material, pharmaceuticals, chemicals, etc.

(11) The large container 1 has a usable space 6 that is bounded by the sidewalls 2, the cover 3, and the floor 4, all made of a woven fabric. The large container 1 is constructed such, that the usable space 6 is leak-proof and capable of reliably containing even very finely powdered bulk material. To create this leak-proof space 6, multiple fabric sheets are welded or fused together to form the sidewalls 2, the cover 3, and the floor 4. The term “welded seam” is used hereinafter to refer to this type of joining, because it is the commonly used term for a welded joining. In contrast to a stitched seam that inevitably has stitch holes, the welded seam 7 is a welded line, in which the fabric sheets of the large container 1 are joined to each other in a stitchless manner, i.e., are not perforated by stitch holes.

(12) There are a number of ways to create the sidewalls 2. Four fabric sheets, or two U-shaped sheets may be welded together, or two parallel edges of a single sheet may be welded together, or a tubular woven fabric, such as can be produced on a circular loom, may be used to provide the four sidewalls 2. A U-shaped sheet also includes an L-shaped sheet with a second straight sheet. The floor 4 is joined to the sidewalls 2 by means of a lower welded seam 7 and the cover 3 by means of an upper welded seam 8 to complete the usable space 6. Thus, the usable space 6 is formed by sidewalls 2, floor 4, and cover 3 that are joined by means of welded seams only, so that the usable space 6 has no stitch holes, i.e., is stitchless and, therefore, leak-proof.

(13) A fill tube or chute 9 is joined to the cover 3 by means of an upper welded seam 10. This fill tube 9 may be made of the same flexible fabric as that of the cover 3. Similarly, a discharge tube or chute 11 is joined to the floor 4 by a lower welded seam 12 and may be made of the same fabric as that of the floor 4.

(14) A belt 14 is sewn onto the hem 5 that extends up above the cover 3. The belt surrounds the hem 5 on the outside. One or more lines of stitching 16 may be stitched through the belt 14 and the hem 5 to securely attach the belt 14 to the hem 5. Parallel stitch lines 16 are shown in FIG. 1, but it is understood that a zig-zag stitch may also be used. The perforations, i.e., stitch holes that are thereby made on the hem 5 and the belt 14 are uncritical regarding the desired leak-proofness of the large container 1, because these perforations are outside the usable space 6.

(15) Lift loops 15 are attached to the hem 5 at the upper four corners of the large container 1. These lift loops 15 allow a conventional hoist means to lift and maneuver the large container 1. The lift loops 15 may be made of the same material as that of the belt 14 and the ends of the loops 15 sewn to the belt 14 and the hem 5.

(16) FIG. 2 illustrates a method of attaching an end of the lift loops 15 to the belt 14, whereby only a small section is shown of the belt 14 and the lift loop 15. An end section of the lift loop 15 is U-shaped and wraps over the belt 14, so that the lift loop 15 makes contact with both sides of the belt 14. Two stitch lines 16 are shown, just as an example, that are stitched through all three layers of the lift loop 15 and the belt 14 to securely fasten the lift loop 15 to the belt 14. Joined in this way, the high tensile forces are passed on from the lift loop 15 to the belt 14, thereby distributing the heavy loading that is initially applied to the lift loops 15. Furthermore, when stitching the loop 15 to the belt 14, the stitching 16 may be stitched at the same time through the hem 5.

(17) Instead of attaching the loops 15 and belt 14 together in a single step, the lift loops 15 may be attached to the belt 14 in a separate step, and then subsequently, the belt 14 with the lift loops 15 be stitched to the hem 5 by means of the stitch lines 16.

(18) In the embodiment shown in FIG. 1, the belt 14 extends all around the hem 5. Alternatively, however, the lift loops 15 may be formed by the belt 14 itself, rather than as separate elements. In this case, the belt 14 is not stitched to the hem 5 at the corners above the cover 3, but rather, is left unattached to the hem, so that material of the belt is lifted up above the upper limit of the hem to form an omega shape (a), i.e., a loop 15.

(19) FIG. 3 is a bottom perspective view of the flexible large container 1 according to the invention, showing the discharge tube 11 welded to the floor 4 by means of the lower welded seam 12. A tie 17 is provided as a means of closing, i.e., tying off, the tube 11. The tie 17 is stitched to the tube 11, so as to leave two free ends that can then be wrapped around the tube 11 to close it.

(20) Although not shown in the figures, it is understood that the tie 17 may also be added to the large container 1 as a separate element or one of its two ends may be loosely stitched tacked to the large container 1, to prevent it from getting lost. The tie 17 is then either detached from the large container 1, for example, cut off or torn off, or is long enough so that, even when still attached to the large container 1, the free end may still be used to tie off the discharge tube 11.

(21) The large container 1 is shown as transparent in FIG. 3 and only up to a part of its overall height, so that the upper areas of the sidewalls 2, the cover 3, the hem 5, etc., are not visible. In the embodiment shown, the large container 1 is constructed as a dimensionally stable container, having a diagonally extending support 18 that is attached to each of two adjacent sidewalls 2 and that extends vertically in the corner area, so as to prevent the two sidewalls from folding in on to each other. The supports 18 have a plurality of openings 19, so that the bulk material can readily flow into or out of the triangular space bounded between the respective sidewalls and the support 18. In order to achieve a complete emptying of the large container 1, the supports 18 do not extend all the way to the floor 4 and to the cover 3, but rather, end some distance before.

(22) FIG. 4 illustrates a conventional seam for stitching two fabric sheets 20 and 21 together. The two fabric sheets 20 and 21 abut each other at an angle and an overlap section in which the fabric sheets are parallel to each other then extends away from the abutted joint, forming a so-called flag 22 and overall an approximately Y-shaped seam area. Forces that are exerted on the large container 1 exert tensile forces on this type of stitched seam and act to pull the seam apart.

(23) FIG. 5 illustrates a method of joining two fabric sheets 20 and 21 together for the large container 1 according to the invention. The edge areas of the two fabric sheets 20 and 21 are placed so as to overlap each other and this overlapped area is then fused or welded together to form a welded seam, i.e., a stitchless seam. The forces acting on this type of seam are shear force, rather than tensile forces, and because of the overlapping construction, this welded seam is capable of withstanding higher loading.

(24) FIG. 6 illustrates the overlapping welded seam shown in FIG. 5, where the floor 4 transitions to the sidewall 2 of the large container 1. In the illustration, the edge section of the fabric sheet for the sidewall 2 is placed on top of the edge section of the fabric sheet for the floor 4 and, once the two sections are welded together, the sidewall 2 is folded upward. It is understood, that the edge section of the fabric sheet for the floor 4 could just as well be placed on top of the edge section of the sheet for the sidewall 2.

(25) It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the large container may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.