Priority of U.S. Provisional Patent Application Ser. No. 61/108,113, filed Oct. 24, 2008, incorporated herein by reference, is hereby claimed.
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1. Field of the Invention
The system of the present invention relates to bulk bags. More particularly the present invention relates to the attachment of lifting loops of bulk bags, along either the bag corners or along the central portion of each side wall in combination with a bottleneck bag feature for allowing greater and more secure stackability of the filled bags.
2. General Background
Bulk bags have been in use for over 30 years in the package industry. The original concept of bulk bags was to create a package that can carry ½ ton to 2 tons of dry flowable products by mechanical means from one factory to another.
While every bag has been designed to safely carry the weight upon four lifting loops built into the top of the bag, the vast majority of bags are shipped upon wood pallets. This has increased the cost of using these bags significantly.
Essentially this has been done in order to speed up the process of picking up the bag for transport. The loops on the top of bulk bags are undependable in position and too small to allow forklift drivers quick and easy access. Almost all current bulk bag designs require the forklift operator to stop and physically place the loops onto the forklift tines or, alternatively, have a second person standing by to place the loops as the operator drives forward.
In the issue of stacking and unstacking bulk bags more safely, the prior art basically reduces all the lifting safety into equal amounts in each corner. That amount is basically ¼ of the total. This is true because each loop is only attached to ¼ of the lifting power of the bag.
In the unstacking process in the current state of the art, it is very difficult for the fork lift operator to see all four loops. The higher the stack, the greater the vision impairment and the greater the chance that the operator will fail to get all four loops. This problem is further aggravated by the fact that the two rear loops are horizontally 36 inches behind the front loops. The front of an elevated bag can completely hide the fork operator's vision of those rear positioned loops.
When this is added to the small target that is also poorly supported and may not be standing up at all, it is easy to see that this method of retrieval is discouraging and unworkable in the present art.
As an alternative to wood pallets, there are two very important features which are addressed. The first is the manner in which the filled bulk bag, which may weigh two or more tons, is lifted from one point to another. The second important feature is whether the filled bulk bags may be stacked firmly and securely upon one other so as to allow more filled bags to be placed in a storage or transport space.
There have been many patents granted on these features of bulk bags over the years. In fact, the present inventor has numerous patents relating to bulk bags, and currently has a patent pending on an improved means for filling a bulk bag so that the bag remains stationary, and the side walls remain, completely upright, as the filled bags are stacked upon one another. However, as is usually the case, there is room for improvement in the combination of the lifting loop attachment coupled with the bottleneck feature of the bag so as to have both easy transport of the filled bags, and secure stackability of the bags, which this invention addresses.
The current invention resolves this issue in a unique manner. Each lifting loop has been designed to reach across large portions of the bag instead of starting and stopping within a single corner of the bag. This provides the fork lift operator with a very large target for easy engagement of the lifting loops.
The present invention solves the problems in the art in a simple and straightforward manner. What is provided is a bulkbag, of the type having four sidewalls, a floor and top portion, all portions stitched together to define the enclosure for the bulk bag housing material. The bag comprises a plurality of four wall panels, which each panel having a first and second vertical edge for sewing into the next adjacent panel along each edge. Prior to sewing the panels together, to each upper edge of each panel there is provided a first and second leg of a lifting loop, so that each loop spans from the first edge to the second edge of each panel. The panels are then sewn together along their edges, and there is defined the bulk bag, with the ends of each of the four lifting loops terminating at the sew line between panels, which may positioned at each bag corner, or in the alternative, in the middle of each sidewall of the bag. There would then be provided a reinforcement ring at each point where a pair of legs of lifting loops are stitched to strengthen the attachment point.
Further there would be provided at each lifting loop attachment points a dart, or stacker seam to define the bottleneck feature of the bag, as disclosed in pending regular U.S. patent application, entitled “Improved Design For Stabilizing Fabric Bulk Bags”, Ser. No. 11/379,436, by the same inventor, incorporated hereinto fully by reference. The lifting loop attachment points would define a vertical seam along the surface of the dart defined by the stacker seam. Further there is provided a back tack stitching feature to prevent spread forces in the filled bag.
Therefore, it is a principal object of the present invention to provide a bulk bag that is more resistant to failure when picked up by less than four loops;
It is a further principal object to provide a bulk bag which allows a forklift operator to be able to view the loops of the bag when bags are stacked and to more easily hit the “target” with the tynes of the forklift.
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
Prior to a discussion of the present invention, reference is made to the prior art conventional attachments as illustrated in
In the manner of attachment as seen in
Turning now to the present invention in
As seen clearly in
Returning now to
For an additional view of the corner feature of the lifting loops 30 stitched between the edges 32, 34 of each of the side walls 11, reference is made to
For purposes of construction, it should be noted that although the lifting loops 30 are made from a standard fabric, each of the lifting loops may be provided with a “stiffener,” within the fabric loop. This “stiffener” would provide support to the loop 30 when the lifting loops are spanning across the width of the bag, they are maintained in the upright position. It is foreseen that the means by which the lifting loops 30 are stiffened, so they are maintained upright as the loops criss-cross from midpoints 70 of adjoining sidewalls 11, or from corner to corner of each bag, would require that the loop material be folded in half to form an upper surface and lower surface. Intermediate the surfaces there is provided two pieces of ½ inch plastic strapping as a stiffening agent. The edges of the folded loop 30 are then stitched together to close folded loop 30 around the strapping. This allows the longer lifting loops 30 to remain upright between attachment points at adjoining walls 11 so that a forklift tine may easily enter the space to lift and transport the bulk bags 10.
This is critical in that it would not therefore require a second person to raise the loops 30 in order of the forklift to stab though the openings. Therefore, when a bag 10 is filled and ready to be moved, the lifting loops 30 would naturally be upright in their position as seen in
Turning now to
Earlier in the discussion of the present invention, and seen throughout the drawing Figures of the present invention, there can be identified a feature which has been labeled as a “dart” 100. This feature, also known as a stacker seam 100, provides the final feature of both embodiments of the bag 10 which is set in place. The stacker seam 100 would define a dart formed in each of these attachment points at the joining of the edges 32, 34 of each of the side walls 11. Each of these stacker seams 100 formed at each of the attachment points of the four lifting loops 30, and would define a bottleneck feature of the bag 10, which enables the bag to maintain its vertical alignment when filled with material so that other bags may be stacked thereupon. This is fully discussed in the pending application referenced above. There would also be provided a back tack stitching point 54, which prevents spreading forces in the bag when the bags are stacked.
It is through this combination of features of the four lifting loops 30 attached to the central points 38 of the sidewalls and the stacker seam 50 defining the bottleneck feature of the bag which allows these new bags to be easily transported and securely and safely stacked upon one another after transport or storage.
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.
The following is a list of suitable parts and materials for the various elements of the preferred embodiment of the present invention.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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Number | Date | Country | |
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61108113 | Oct 2008 | US |