Cargo airbag

Abstract: An airbag (20) for use in a cargo bay of a transport vehicle for buffering and stabilising a load, usually large paper rolls or drums, comprises two inflatable, gas tight bladders (22, 24) surrounded by a multi-ply paper container (26). The bladders (22, 24) are situated in a partially overlapping relationship with respect to one another. This enables a load with a rounded configuration to be cradled, buffered and stabilised while minimising the need for additional packing or supporting materials.

Description: The present invention is directed to cargo airbags that are placed between loads, such as large paper rolls or drums and the like, in a transport vehicle, such as a train, ship, truck, aircraft and the like, in order to brace the load from shifting or damaging itself during transport because of voids between the loads, such as are known from US-A-4 136 788, and, more particularly to an improved airbag that minimises the need for additional buffer material. It is well known in the art to use inflatable airbags for bracing a load, such as large paper rolls. These airbags typically consist of plastic inflatable bladder means surrounded by some form of container, usually a multi-ply paper container. The container prevents the bladder from being punctured by the load or other objects in the cargo bay. The airbag includes an air inlet valve so that the bladder can be inflated. In order to brace a load using this type of airbag, special contour roll buffers or chocks, which will be described in detail subsequently with respect to Figure 5, are needed to hold the airbag between the rolls or between a roll and the wall. The contour roll buffers or chocks complement the shape of the rolls and hold the rolls. Also, additional dunnage is often needed to pad the contact point between the airbag and the contour roll buffers. If the contour roll buffers and additional dunnage are not used, the airbag has a tendency to slip out from between the rolls. In use, the airbag is placed between the contour roll buffers and additional dunnage in a deflated condition and then inflated through the valve with high pressure air to the desired air pressure, usually 100 to 400 Pa (2 to 8 pounds per square inch) depending on the size of the bladder and the container structure. In the inflated condition, the voids between the rolls are filled and the rolls are stabilised and ready for transport. Since the design of the airbag necessitates the use of contour roller buffers and additional dunnage, this presents a serious disadvantage. These items add extra weight to the load and increase the total expense. They also take up additional valuable space that could be used for more rolls or drums during a shipment. The present invention presents a novel airbag that is intended to minimise these problems, as well as to present several other improvements. According to this invention a cargo airbag comprises inflatable bladder means and an expandable container enclosing the bladder means; and is characterised in that the bladder means consists of a plurality of inflatable bladders which, when deflated, overlie each other by a pre-determined distance. The cargo airbag in accordance with this invention can be used as a brace between loads having a rounded configuration in a transport vehicle. It minimises the amount of additional buffer material needed to support such a load. A particular example of an airbag in accordance with this invention will now be described and contrasted with the prior art with reference to the accompanying drawings, in which:- Figure 1 is a simplified perspective view of airbag having an over wrap or outer container partially broken away in order to show two deflated bladders contained therein; Figure 2 is a simplified partial cross sectional view of a deflated airbag of the present invention showing the overlapping bladders within a container formed from paper or other suitable sheet material; Figure 3 is a simplified partial cross sectional view similar to Figure 2, but showing the airbag of the present invention in an inflated condition; Figure 4 is a simplified cross sectional view of an inflated airbag of the present invention between a load; and Figure 5 is a simplified cross sectional view of an inflated prior art airbag between a load. As illustrated in the Figures, the present invention is directed to an airbag 20 generally comprised of two bladders 22 and 24 and a container 26 in a novel arrangement. As illustrated in Figure 4, the airbag 20 of the present invention is particularly suited for use to hold and stabilise various large objects having cylindrical or other curved or irregular surfaces, such as large paper rolls or drums 28 and 30 during transport by filling a void left between the rolls 28 and 30 when they are placed side by side. Each bladder 22 and 24 may be a seamless tube of polyethylene, rubber or the like and of typical construction. The bladders 22 and 24 are sealed so as to be gas tight. The bladder size may vary depending on the size of the load 28 and 30 that the airbag 20 is supporting, but bladders 22 and 24 are preferably of equal size. As shown in Figure 1, the bladders 22 and 24 lie in an overlapping relationship. As shown in Figures 2 and 3, this overlap 32 occurs along the centre 34 of the airbag 20. The overlap 32 may vary depending on the size of the load 28 and 30 to be supported. For example, if 0.10 to 0.15 mm (4 to 6 mil) polyethylene bladders are used, the bladders should overlap each other a distance of approximately 50 to 100 mm (2 to 4 inches) in the deflated condition. Thus, when the airbag 20 is placed between two rolls 28 and 30 or a roll and a wall (not shown) and then inflated, the bladders 22 and 24 will overlap each other. This overlap 32 distributes the load of the roll or rolls 28 and 30 and prevents the bladders 22 and 24 from being completely collapsed and pinched together at their overlapping ends 23 and 25. As shown in Figure 4, the shape of the airbag 20 will contour to the shape of the rolls 28 and 30 when inflated. The transverse dimension of the container or relatively non-elastic bag 26 is less than twice the corresponding dimension of each bladder 22 and 24 so that the bladders 22 and 24 will be retained in their overlapping relation when inflated as shown in Figures 3 and 4. When the airbag 20 is inflated, overlapping portions 23 and 25 of the bladder 22 and 24 at the centre 34 of the airbag 20 are thinner than the outer marginal portions 27 and 29 of the bladders adjacent the ends 36 and 38 of the airbag 20. When the airbag 20 is inflated and confined between objects of cargo such as the rolls 28 and 30 shown in Figure 4, a portion of the sides 40 and 42 of the airbag 20 take on a concave shape that conforms to the shape of the rolls 28 and 30. Thus, the shape of the inflated airbag 20 will prevent the airbag 20 from slipping out from between the rolls 28 and 30 or a roll and a wall. This eliminates the need for the special contour roll buffers 44 and 46 and additional dunnage 48 and 50 that is needed when a prior art single bladder airbag 52, as shown in Figure 5, is used for stabilising two rolls or drums 54 and 56. Thus, the extra weight and material of these items is eliminated. Furthermore, since only the dual bladder airbag 20 is needed to buffer and fill the void between the rolls 28 and 30, less space is wasted and more rolls can be transported during a single shipment. The bladders 22 and 24 are enclosed in a container 26 of known construction such as the multi-ply dunnage bag disclosed in U.S. Patent No. 4,136,788 whose disclosure is incorporated herein by reference. The container 26 is comprised of multiple layers of suitable sheet material such as paper, usually four to eight plies, and completely encloses the bladders 22 and 24 within. The size of the container 26 may vary and depends on the size of the bladders 22 and 24 being used. The container 26 prevents the bladders 22 and 24 from being punctured by the load 28 and 30 or by other objects which may be found in a cargo bay. In the preferred embodiment shown in the Figures, each of the bladders 22 and 24 includes a valve 60 and 62 for inflating the respective bladder 22 and 24. It is to be understood, however, that it is contemplated in the design that a single valve could be used to inflate both bladders. The valves 60 and 62 are located adjacent one margin 61 of the container 26 and extend through holes 64 and 66, respectively, in the container 26 so as to allow the bladders 22 and 24 to be inflated. The bladders 22 and 24 are inflated by high pressure air from an appropriate source to a desired air pressure, usually 100 to 400 Pa (2 to 8 pounds per square inch), depending on the size and the container structure of the airbag. The bladders 22 and 24 are attached to the container 26 by way of the valves 60 and 62 and a patch or tab of adhesive 68 and 70. The adhesive patches 68 and 70 are preferably constructed of a pressure sensitive or hot melt adhesive. The adhesive patches 68 and 70 are located adjacent to margin 69. Margin 69 is opposite to the margin 61. The adhesive patches 68 and 70 must be near the margin 69 in order to allow the bladders 22 and 24 to move relative to the container 26 during inflation and to fully inflate. When the airbag 20 is oriented in a vertical position with the margin 69 being positioned higher or above the margin 61, the adhesive patches 68 and 70 will prevent the bladders 22 and 24 from sagging, sliding or otherwise falling within the container 26 when the bladders 22 and 24 are in the deflated condition. This will prevent incomplete inflation of one or both of the bladders 22 and 24 which would result in pinching of the bladders 22 and 24 and/or non-uniform inflation and support. When the bladders 22 and 24 are inflated, the adhesive patches 68 and 70 will release and the bladders 22 and 24 will not be attached to the container 26. As shown in Figure 3, the bladders 22 and 24 are in an inflated configuration while being in a relatively non-contacting relationship with the inside wall 58 of the container 26. This is only for purposes of illustration to show clarity. It is to be understood that when the bladders 22 and 24 are inflated, the majority of the bladders 22 and 24 will contact the inside wall 58 of the container 26. A slip sheet 72, as shown in Figure 3, may be included in the design of the airbag 20. The slip sheet 72 is placed between the two bladders 22 and 24 and is used to minimise the amount of friction between the bladders 22 and 24. Without a slip sheet 72, the bladders 22 and 24 may rub against each other. The slip sheet 72 is not attached to the bladders 22 and 24 or the container 26, as shown in Figure 3, and thus is free floating in the airbag 20. The slip sheet 72 is generally comprised of multiple layers of paper, usually one to three plies. The size of the slip sheet 72 may vary depending on the size of the bladders 22 and 24. A hole or aperture 74 may be included in the design of the slip sheet 72 to allow a valve 60 to pass there-through if needed. When the airbag 20 is manufactured, the bladders 22 and 24 are flat, as shown in Figure 2. The bladders 22 and 24 are placed in the desired overlapping relationship and the slip sheet 72, if being used, is placed between the bladders 22 and 24. Adhesive patches 68 and 70 are placed on the bladders 22 and 24. The bladders 22 and 24 and the slip sheet 72, if used, are then completely enclosed in the container 26 by known methods. The adhesive patches 68 and 70 bond with the container 26. The valves 60 and 62 protrude from the airbag 20. When the airbag 20 is being used to buffer and stabilise a load 28 and 30, it is placed in the void between the rolls or drums 28 and 30 in a deflated condition. A worker then inflates the bladders 22 and 24 by injecting high pressure air from an appropriate source through the valves 60 and 62 to the desired pressure. In order to do this, one bladder 22 may first be inflated and then the second bladder 24 will be inflated or, both bladders 22 and 24 may be inflated at the same time. When the airbag 20 is inflated, the adhesive patches 68 and 70 will release from the container 26. The airbag 20 conforms to the shape of the rolls 28 and 30, as shown in Figure 4 and as described hereinabove, and buffers and stabilises the load 28 and 30. After use, the airbag 20 may be disposed of, or deflated by appropriate means for re-use.

Claims: A cargo airbag (2) for use as a brace between heavy loads comprising inflatable bladder means and an expandable container (26) enclosing the bladder means; characterised in that the bladder means consists of a plurality of inflatable bladders (22, 24) which, when deflated overlie each other by a pre-determined distance (32). A cargo airbag according to claim 1, wherein the pre-determined distance (32) is less than the transverse width of the bladders (22, 24). A cargo airbag according to claim 1 or 2, wherein the pre-determined distance (32) is less than one third of the transverse width of the bladders (22, 24). A cargo airbag according to any one of the preceding claims, wherein the pre-determined distance (32) is about 50 to 100 mm (2 to 4 inches). A cargo airbag according to any one of the preceding claims, wherein at least one of the bladders (22, 24) has an air inlet valve (60, 62), and the expandable container (26) has means defining an opening for allowing the valve (60, 62) to pass there-through. A cargo airbag according to any one of the preceding claims, further including a slip sheet (72) disposed between the bladders (22, 24). A cargo airbag according to any one of the preceding claims, further including means (68, 70) for preventing the bladders (22, 24) from sliding within the expandable container (26) when the airbag (20) is placed upright. A cargo airbag according to claim 7, wherein the means (68, 70) for preventing the bladder (22, 24) from sliding is an adhesive material. A cargo airbag according to any one of the preceding claims, wherein the expandable container (26) comprises a plurality of plies of paper. A cargo airbag according to any one of the preceding claims, in which the bladder means consists of only two inflatable bladders.

Inventors: GOSHORN DOUGLAS A, KEENAN THOMAS C, GOSHORN, DOUGLAS A., KEENAN, THOMAS C.
Applicants: SHIPPERS PAPER PROD, SHIPPERS PAPER PRODUCTS CO.
Application year: 1993
Main classification: B65D90
IPC codes: B60P7, B65D81, B61D45