Method of inflating a dunnage bag, inflating system, and container

Abstract

 A method of inflating a dunnage bag (16) in a container (10) comprises inflating the dunnage bag (16), monitoring a parameter characterizing an effect of the inflating dunnage bag (16) to the container 10), and terminating inflating the dunnage bag (16) when the parameter reaches a predetermined threshold, characterized in that the method further comprises prior to inflating the dunnage bag (16), urging a portion of the container (10) inwardly, and terminating inflating the dunnage bag (16) when the initially inwardly urged portion is urged outwardly by the dunnage bag (16) into a predetermined position and/or is urged outwardly by the dunnage bag (16) by a predetermined distance and/or is urged outwardly by the dunnage bag (16) with a predetermined load.

Description

[0001] The invention relates to a method of inflating a dunnage bag in a container, to an inflating system for inflating a dunnage bag in a container, and to a container for carrying articles for shipment according to the preambles of the independent claims.

[0002] End of line packaging of random products usually involves the application of protective dunnage- or stuffing materials preventing damage to the packed articles during shipping. This dunnage very often consists of an inflatable bag which is placed into the container after the articles being placed in the container and prior to closing the container. After closing the container, the bag is inflated with air in order to fill the void space in the container and to prevent the articles inside the container from moving during shipment.

[0003] A method for inflating a dunnage bag is disclosed in EP 1 109 719 B1. With this method, the outside surface of the container is monitored during inflating the dunnage bag. After the outside surface of the container has started buckling outwardly due to the pressure exerted by the inflated dunnage bag to the interior surfaces of the container, inflation is stopped. An important drawback of this method is that the container, after completion of the inflation of the dunnage bag, has no more flat outside surfaces, since the outside surfaces are deflected outwardly. This makes it difficult, when not impossible to stack containers upon each other.

[0004] It is therefore an object of the present invention to provide a method, a system, and a container eliminating the above-mentioned drawback while reliably blocking the articles inside the container by the inflated dunnage bag.

[0005] The invention proposes a method of inflating a dunnage bag in a container, an inflating system for inflating a dunnage bag in a container, and a container according to the independent claims. More detailed aspects of the invention are claimed in the dependent claims. Further, important features of the invention are disclosed in this specification and in the attached drawing.

[0006] A major benefit of the present invention is that inflation of the dunnage bag can be stopped prior to the container walls starting to deflect outwardly from their unloaded flat configuration. By consequence, after full inflation of the dunnage bag, which insures that the articles are prevented from moving around inside the container, the container still has its "unloaded" shape with flat exterior wall surfaces. Thus, the containers to which the inventive method is applied can be stacked upon each other to piles having a good stability.

[0007] In order to achieve this result, no complicate and/or expensive measurement techniques are required. Instead, according to the present invention, a pre-load or pre-deformation is applied to a container surface, this load and/or deflection being directed against the load and/or deflection exerted later to the container portion when the dunnage bag is inflated. This allows to detect a sufficient inflation of the dunnage bag much earlier than with the prior art systems, allowing to prevent the container walls from being deflected outwardly.

[0008] As a parameter characterizing the effect of the inflating dunnage bag to the container, a predetermined position of the container portion can be used. This position is preferably selected such that the outside surfaces of the container are just prevented from being flexed outwardly. Further, it is possible to use a predetermined distance as the parameter characterizing the effect of the inflating dunnage bag to the container. This means, that inflation is stopped when the container portion has traveled over the predetermined distance during inflation. Again, this predetermined distance is preferably selected such that the outside surfaces of the container are just prevented from being flexed outwardly. Finally, it is possible to use a predetermined load as parameter characterizing the effect of the inflating dunnage bag to the container. This means, that inflation is stopped when the force which is necessary to inwardly urge the container portion reaches a predetermined value. Again, this predetermined load is selected such that the surfaces of the container are just prevented from being flexed outwardly. It is to be understood that the predetermined values can be acquired during pretests on a typical container. During these pretests, the relevant parameters are determined during inflation of the dunnage bag for a condition just before the outside surfaces start to deflect outwardly.

[0009] In a preferred embodiment, urging the portion inwardly and detecting the predetermined position and/or the predetermined distance and/or the predetermined load involves using the same member, the member preferably being a rod connected to a driving means and to a sensor means acquiring the actual position of the distal rod tip and/or the actual movement distance of the distal rod tip and/or the actual load acting on the distal rod tip. Using the same member for urging the container portion inwardly as well as for detecting the action of the inflating dunnage bag on the container portion reduces system complexity and costs.

[0010] In yet another embodiment of the invention the initially inwardly urged portion comprises an upper surface of the container. This surface is easily accessible therefore allowing to easily realize the inventive method.

[0011] In the case the initially inwardly urged portion comprises approximately the center of the upper surface of the container, the effect of the inflating dunnage bag on the container portion can be detected with high reliability.

[0012] The initially inwardly urged portion may comprise a closing flap situated inside the container. This embodiment is based on the fact that a container for transporting articles, in particular a container made of corrugated cardboard, usually comprises four closing flaps. Two of these closing flaps, normally the narrow side closing flaps, are first bent into their closing position, and then the two other closing flaps, usually the long side closing flaps, are bent in their closing position. Thereafter, the container is sealed for instance by using an adhesive tape closing the gap between the opposed edges of those two closing flaps that have been bent into their closing position as the latest. Thus, those closing flaps that were first bent into their closing position are situated inside the container after its closure. By using one of these closing flaps as the portion of the container being urged inwardly, no manipulation of an exterior surface of the container is necessary for detecting the action of the inflating dunnage bag.

[0013] In order to obtain access to the closing flap situated inside the container, the method may comprise the step of creating an opening in an outside wall of the container allowing insertion of a member for urging the closing flap inwardly. This step may comprise punching out an elongated contour, leaving a one-sided hinged flap inside the contour. This hinged flap is then bent away by the member which is used for urging inwardly the closing flap situated inside the container. After completion of the inflation and retracting the urging member out of the container, the opening is again closed by the resilient movement of the hinged flap substantially back into its initial "rest" position. This provides for a reliable protection of the articles inside the container.

[0014] A more simple solution to provide access to the closing flap situated inside the container is to simply drill a hole in an outside wall, in particular a top wall of the container.

[0015] The opening may be situated close to a fixation position of the dunnage bag with the container or away from this fixation position. If it is close to the fixation position, the probability is increased that the inflating dunnage bag really acts on the closing flap at the location where the urging member is applied. If the opening is more distant from the fixation position, any negative interaction between the inflation means and the monitoring means for monitoring the effect of the inflating dunnage bag to the container portion is avoided.

[0016] Other features and advantages of the invention will become apparent from the following detailed description. It is to be understood that the same reference signs will be used in different embodiments for those elements and regions having equivalent functional characteristics.

FIG. 1

is an overall perspective and partially transparent view of a container comprising in its interior articles to be shipped and an inflated dunnage bag;

FIG. 2

is a more detailed perspective view of a portion of the container of FIG. 1;

FIG. 3

is a schematic side view of the container of FIG. 1, wherein the dunnage bag is not inflated yet;

FIG. 4

is a view similar to FIG. 3 showing additionally inflating means for inflating the dunnage bag and monitoring and urging means acting on a top surface of the container prior to starting inflation of the dunnage bag;

FIG. 5

is a view similar to FIG. 4 during inflation of the dunnage bag;

FIG. 6

is a view similar to FIG. 5, wherein inflation of the dunnage bag is completed;

FIG. 7

is a view similar to FIG. 3 of a second embodiment of a container showing closing flaps situated inside the container, wherein the dunnage bag is not inflated yet;

FIG. 8

is a view similar to FIG. 7, wherein an urging and monitoring means is urging a closing flap inwardly;

FIG. 9

is a view similar to FIG. 8 during inflation of the dunnage bag;

FIG. 10

is a view similar to FIG. 9, wherein inflation of the dunnage bag is completed; and

FIG. 11

is a perspective view from above on a container with a one-sided hinged flap in a top surface.

[0017] Referring to FIGS. 1 and 2, a container 10 comprises two articles 12 and an inflated dunnage means 14 for filling a void space in container 10. The inflated dunnage means 14 comprises an inflatable dunnage bag 16 and an inflation valve 18 for inflating the dunnage bag 16 with gas, e.g. air. The articles 12 are wedged between the inflated dunnage bag 16 and side walls 20 and top wall 22 of container 10. Thus, articles 12 are prevented from moving around in container 10 while being shipped.

[0018] Inflation valve 18 comprises a card-type solid member 24 made of a flat thin but rigid and rectangular sheet or strip or band material of polyethylene in one step by molding or punching out. Solid member 24 comprises a clip-or hook-shape connecting portion 26, and side wall 20 of container 10 has a hole 28 nearby to an upper corner of container 10. Clip- or hook-shape connecting portion 26 is formed during punching or molding solid member 24 and looks like a punching-out. As can best be seen from FIG. 2, clip-or hook-shape connecting portion 26 is pierced downwardly into a circumferential surface 30 of hole 28 such that it penetrates into the substance of the material from which container 10 is made, e.g. corrugated cardboard, to attach solid member 24 very close and parallel to sidewall 20 of container 10 and oriented with its longitudinal sides 32 parallel to vertical edges 34 of container 10. Preferably, solid member 24 is attached close to the corner built by edge 34 of container 10, as shown in FIGS. 1 and 2.

[0019] Solid member 24 comprises an inflation opening 36 located nearby connecting portion 26. Inflation opening 36 is also formed when solid member 24 is manufactured by creating simply a hole or, as shown in FIGS. 1 and 2, a clip- or hook-shape protrusion 38 of a shape similar to connecting portion 26, however having a shorter length. As may be seen from FIG. 2, inflation opening 36 is located at hole 28, thus allowing inflating dunnage bag 16 from outside of container 10 as will be explained in more detail further below.

[0020] An inflating system 40 for inflating the dunnage bag 16 is now explained with reference to FIG. 4: The inflating system 40 comprises inflating means 42 for inflating the dunnage bag 16 through inflation opening 36. Inflating means 42 may comprise, for example, an inflation nozzle which is applied to hole 28 and which is connected to a source of pressurized air.

[0021] Further, the inflating system 40 comprises urging means 44, comprising an elongated rod 44 with a distal end portion or tip 45 connected to a driving means 46 for moving rod 44 in a direction parallel to its longitudinal axis.

[0022] Further, inflating system 40 comprises monitoring means 48 in the form of a displacement sensor configured to sense a movement distance of the rod.

[0023] Both the driving means 46 and the monitoring means 48 are connected to control means 50. Also, inflating means 42 is connected to control means 50. By this connection, monitoring means 48 transmits signals corresponding to the acquired movement distance to the control means. The control means 50 sends signals to the driving means 46 for moving rod 44, and sends signals to inflating means 42 for inflating dunnage bag 16.

[0024] Inflation of dunnage bag 16 is performed according to the following method: As shown in FIG. 3, prior to starting the inflation procedure, the dunnage bag 16 is arranged over articles 12, but is still not filled with air. Then, the container is closed.

[0025] The container is now moved to a specifically arranged station where the inflation procedure is executed. The container 10 is moved to this station by an appropriate transport means (not shown), such as a conveyor belt or the like, and is stopped at the station by a stop member (not shown). Hole 28 and solid member 24 are preferably arranged close to that corner or edge of the container 10, which is closest to the stop member. In a first step, driving means 46 are activated by control means 50 such that rod 44 urges the center of the upper surface or top wall 22, respectively of container 10 inwardly, that is in the direction of the interior void inside the container 10. This movement of rod 44 is shown by arrow 52 in FIG. 4. As can be seen from FIG. 4, the upper surface 22 of container 10 is flexed downwardly by the action of rod 44. The movement distance of rod 44 is predetermined and corresponds to a value set in a pretest such that the upper surface 22 of container 10 is not damaged.

[0026] After rod 44 has reached its preset "extended" position, driving means 46 is stopped. Now, control means 50 activates inflating means 42 such that inflation of the dunnage bag 16 is started. Since hole 28 and solid member 24 are preferably arranged close to that corner or edge of the container 10, which is closest to the stop member, hole 28 and inflation opening 36 are positioned with high precision relative to the inflation means cooperating with hole 28 and inflation opening 36. As can be seen from FIG. 5, dunnage bag 16 expands under the increasing pressure inside dunnage bag 16, as indicated by arrows 54 in FIG. 5. In the course of its expansion, dunnage bag 16 reaches the inner surface of top wall 22 of container 10. With the further increasing pressure inside dunnage bag 16, top wall 22 of container 10 is urged outwardly against the action of rod 44. Thus, rod 44 is moved upwards in the direction of arrow 46 in FIG. 5. This movement of rod 44 is detected and monitored by sensor 48.

[0027] As soon as top wall 22 reaches its undeflected flat position, as shown in FIG. 6, which is sensed by sensor 48 and control means 50 taking into consideration the movement distance of rod 44 after inflation has started, control means 50 influence inflating means 42 to stop inflation, such that no further air is introduced into dunnage bag 16. In this condition, the outside surfaces of container 10 are just prevented from being flexed outwardly, since they are brought back to their "unloaded" flat condition. Nevertheless, dunnage bag 16 is sufficiently pressurized to reliably maintain articles 12 in place and prevent them from moving around during further shipment of container 10.

[0028] In the embodiment of FIGS. 3 to 6, inflation of dunnage bag 16 is controlled by monitoring the movement distance of rod 44 during inflation of dunnage bag 16. Alternatively or additionally it is possible to monitor the absolute or relative position of the application point of rod 44 to a stationary edge of top wall 22, that is to stop inflation of dunnage bag 16 when this application point during inflation of dunnage bag 16 reaches again its original position justprior to starting urging top wall 22 inwardly. Further, it is also possible to monitor the load acting on rod 44 during inflation of dunnage bag 16, that is the force acting in longitudinal direction of rod 44.

[0029] Referring now to FIGS. 7 to 10, a second embodiment of container 10 and of the method for controlling inflation of dunnage bag 16 will be explained. In this embodiment, a closing flap 58 situated inside container 10 after its closure is used for monitoring inflation of dunnage bag 16. The closing flaps of such typical container 10 are shown in more detail in FIG. 1: Typically, such a container comprises, at its upper end, two narrow side closing flaps 58 and 60 and two long side closing flaps 62 and 64. In order to close container 10, after articles 12 and dunnage means 14 have been arranged inside container 10, usually first both narrow side closing flaps 58 and 60 are bent inwardly. Then, both long side closing flaps 62 and 64 are bent inwardly such that they build top wall 22 of container 10. Finally, the gap between opposed edges (without reference numerals in FIG. 1) of long side closing flaps 62 and 64 is sealed with an adhesive tape 66. As can be seen from FIG. 7, in long side closing flap 62 an opening 68 is provided, the opening 68 being over narrow side closing flap 58.

[0030] Inflation of dunnage bag 16 is performed similarly to the method described with reference to FIGS. 3 to 6. However, prior to starting inflation, rod 44 is inserted through opening 68 such that it urges narrow side closing flap 58 inwardly. As shown in FIGS. 9 and 10, during inflation of dunnage bag 16, narrow side closing flap 58 is urged upwardly by inflating dunnage bag 16, this movement being sensed by rod 44 and sensor 48. When narrow side closing flap 58 approximately reaches its original position (approximately equivalent to its unloaded position prior to being urged inwardly, see FIG. 10), inflation of dunnage bag 16 is stopped. As can be seen from FIG. 10, this allows to stop inflation just prior to top wall 22 being deflected outwardly. Nevertheless, dunnage bag 16 has sufficiently expanded such that articles 12 are reliably held in position and are prevented from moving around during shipment of container 10. Although shown differently in FIGS. 7-10, opening 68 and inflation valve 18 may be positioned close to each other, and close to a stop member stopping the container 10 in the inflation unit, in order to provide optimum positioning of the container relative to the inflation means and rod 44.

[0031] Opening 68 may be realized simply by drilling a hole in one of long side closing flaps 62 or 64. As can be seen from FIG. 11, opening 68 may be realized alternatively by punching out an elongated contour 70, leaving a one-sided hinged flap 72 inside the contour 70 in one of long side closing flaps 62 and 64. In operation, rod 44 urges or flexes, respectively, away flap 72 when it is inserted, such that it can reach and contact narrow side closing flap 58 as shown in FIGS. 8 to 10. After retraction of rod 44 from the inside of container 10, that is, after completion of inflation of dunnage bag 16, flap 72 returns into its original position, thus closing opening 68 again.

Claims

1. A method of inflating a dunnage bag (16) in a container (10), said method comprising
inflating the dunnage bag (16),
monitoring a parameter characterizing an effect of the inflating dunnage bag (16) to the container (10), and terminating inflating the dunnage bag (16) when the parameter reaches a predetermined threshold,
characterized in that the method further comprises
prior to inflating the dunnage bag (16), urging a portion (22; 58) of the container (10) inwardly, and
terminating inflating the dunnage bag (16) when the initially inwardly urged portion (22; 58) is urged outwardly by the dunnage bag (16) into a predetermined position and/or is urged outwardly by the dunnage bag (16) by a predetermined distance and/or is urged outwardly by the dunnage bag (16) with a predetermined load.

2. The method of claim 1, wherein the predetermined position and/or the predetermined distance and/or the predetermined load is selected such that the outside surfaces of the container (10) are just prevented from being flexed outwardly.

3. The method of anyone of claims 1 or 2, wherein urging the portion (22; 58) inwardly and detecting the predetermined position and/or the predetermined distance and/or the predetermined load involves using the same member, the member preferably being a rod (44) connected to a driving means (46) and to a sensor means (48) acquiring the actual position of the distal rod tip (45) and/or the actual movement distance of the distal rod tip (45) and/or the actual load acting on the distal rod tip (45).

4. The method of any of the preceding claims, wherein the initially inwardly urged portion comprises an upper surface (22) of the container (10).

5. The method of claim 4, wherein the initially inwardly urged portion comprises approximately the center of the upper surface (22) of the container (10).

6. The method of anyone of the preceding claims, wherein the initially inwardly urged portion comprises a closing flap (58) situated inside the container (10).

7. The method of claim 6, wherein the closing flap is a narrow side closing flap.

8. The method of one of claims 6 or 7, further comprising the step of creating an opening (68) in an outside wall of the container (10), in particular a top wall, allowing insertion of a member (44) for inwardly urging the closing flap (58).

9. The method of claim 8, wherein the step of creating the opening (68) comprises punching out an elongated contour (70), leaving a one sided hinged flap (72) inside the contour (70).

10. The method of claim 8, wherein the step of creating the opening (68) comprises drilling or punching out a hole.

11. The method of anyone of claims 8 to 10, wherein the opening (68) is situated close to a fixation position of the dunnage bag (16) with the container (10).

12. The method of anyone of claims 8 to 10, wherein the opening (68) is situated away from a fixation position of the dunnage bag (16) with the container (10).

13. An inflating system (40) for inflating a dunnage bag (16) in a container (10), said system comprising
inflating means (42) for inflating the dunnage bag (16),
monitoring means (48) for monitoring a parameter characterizing an effect of the inflating dunnage bag (16) to the container (10), and
control means (50) terminating inflating the dunnage bag (16) when the monitored parameter reaches a predetermined threshold,
characterized in that the system (40) further comprises
urging means for urging a portion (22; 58) of the container (10) inwardly prior to inflating the dunnage bag (16), and
the control means (50) being programmed in order to terminate inflating the dunnage bag (16) when the initially inwardly urged portion (22; 58) is urged outwardly by the dunnage bag (16) into a predetermined position and/or is urged outwardly by the dunnage bag (16) by a predetermined distance and/or is urged outwardly by the dunnage bag (16) with a predetermined load.

14. A container (10) for carrying articles (12) for shipment, characterized in that the container (10) comprises an opening (68) in an outside wall (20) of the container (10) allowing insertion of a member (24) for inwardly urging a closing flap (58) after the container (10) being closed.

15. The container (10) of claim 14, wherein the opening (68) comprises an elongated contour (70), leaving a one sided hinged flap (72) inside the contour (70).

Drawing