The present disclosure relates generally to a pneumatic system for use with dunnage bags, which are generally used to limit movement of cargo during transportation of the cargo.
Dunnage bags may be used to secure the cargo of tractor trailer trucks, railroad cars, and other vehicles. Typically, the dunnage bags are positioned and inflated on the sides of the cargo, such as between the cargo and walls of the respective cargo container. Once inflated, the dunnage bags provide a secure fit for the cargo in the container, preventing unintended and undesired shifting, sliding, or other movement of the cargo during transportation.
Typically the dunnage bags are formed from paper and interiorly lined with plastic. Other dunnage bags may be formed entirely from plastic. Paper and plastic materials allow for inexpensive manufacturing and replacement of dunnage bags, however the materials are not generally designed to withstand pressures above around 10 to 15 pounds per square inch (psi). In a cargo container of tractor trailer truck, the dunnage bags are typically inflated to pressures of about 2 psi, substantially below the burst pressures at which the dunnage bags would fail. In a freight car of train, the dunnage bags may be inflated to pressures of 4 to 6 psi.
A typical cargo container for a tractor trailer truck may use twenty or more dunnage bags at a time, such as using ten or more on each side of the interior of the container. A trucker or cargo loader manually positions and inflates each dunnage bag to secure the cargo. Once positioned, the dunnage bags are then inflated, one at a time, by a pressure-regulated source. The supply pressure is typically regulated to a safe pressure for the dunnage bags, such as around 2 psi. Inflation at 2 psi may correspond to a relatively low air flow rate, and the task of securing the cargo by positioning and inflating each dunnage bag may be quite time consuming.
One embodiment of the invention relates to a pneumatic system for use with dunnage bags. The pneumatic system includes a manifold configured to communicate pressurized air from a source, and a station. The station includes a conduit that is coupled to the manifold and that has an outlet configured to communicate the pressurized air with a dunnage bag. The station further includes a valve coupled to the conduit. The valve is biased closed and configured to open at a pressure corresponding to a predetermined fill pressure of the dunnage bag.
Another embodiment of the invention relates to a pneumatic system for use with dunnage bags, which includes a manifold, a station, and an evacuation assembly. The manifold is configured to communicate pressurized air from a source. The station includes a conduit coupled to the manifold. The conduit has an outlet configured to communicate the pressurized air with a dunnage bag. The evacuation assembly is configured to deflate the dunnage bag by actively suctioning air from the dunnage bag through the manifold.
Yet another embodiment of the invention relates to a dunnage bag assembly. The dunnage bag assembly includes a dunnage bag and a check valve. The dunnage bag is configured to be inflated with pressurized air and is designed to limit movement of cargo in a cargo container during transportation of the cargo. The check valve is biased closed and configured to open when pressure in the dunnage bag reaches a predetermined fill pressure.
Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.
The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, in which:
Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
Referring to
According to an exemplary embodiment, the trailer 114 is coupled to the towing vehicle 112 at a fifth wheel coupling 128. The trailer 114 may include landing gear 134 to support a container 116 when the trailer 114 is detached from the towing vehicle 112. The container 116 of the trailer 114 includes cargo space (see
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In some embodiments, the pneumatic system 136 includes two rows 148 of stations 144 with at least three stations 144 in each row 148 (see
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The conduits 146 may be formed from a flexible hose material allowing an operator to maneuver the dunnage bags 138 into a desired location (within the reach of the conduit 146). Flexibility of the conduits 146 allows for maneuvering of the dunnage bags 138 as may be beneficial given a unique loading configuration or cargo geometry. In contemplated embodiments, the conduits 146 may be extendable or retractable or may be sufficiently long (e.g., at least five feet) so as to allow for a wide range of maneuverability and placement of the associated dunnage bag 138.
According to an exemplary embodiment, fasteners 156, such as clips or hooks, may extend from the manifold 152 or elsewhere to support the dunnage bags 138. The fasteners 156 may be positioned to attach to upper corners of the dunnage bags 138. In contemplated embodiments, fasteners may slide and lock into place on a rail, which allows for specific horizontal placement and support of the dunnage bags 138. In some embodiments, the fasteners may extend from a reel with an automatic rewind, allowing for vertical adjustment of the dunnage bags 138. In preferred applications, the manifold 152 is mounted to the container 116 above the load line so that the manifold 152 is readily accessible while cargo 142 is present in the container 116.
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When pressure in the dunnage bag 222 is low, the pneumatic system 210 is configured to communicate pressurized air from the manifold 218, through the conduit 224, and to the dunnage bag 222 for inflation thereof (see
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According to an exemplary embodiment, the pneumatic system includes a configuration of valving designed to control inflation of the dunnage bags 222. A valve 226 (e.g., relief valve) is used to prevent over-inflation of the dunnage bags 222. In some embodiments, the station includes a junction 236 (e.g., T-fitting) connecting the conduit 224 to the manifold 218, and another connector 238 fastening the conduit 224 to the dunnage bag 222. The connector 238 may include a threaded connector that locks and unlocks with a thumb-release button (see also connector 162 as shown in
During use of the pneumatic system 210, as pressurized air is delivered to the dunnage bag 222 the dunnage bag 222 inflates and pressure in the dunnage bag 222 increases. Inflation of the dunnage bag 222, in turn, causes an increased pressure in the conduit 224. When the pressure in the conduit 224 reaches a magnitude corresponding to a predetermined fill pressure of the dunnage bag 222, a valve 226 opens to release additional pressurized air communicated through the conduit 224 (see also biased check valve 160 as shown in
According to an exemplary embodiment, the valve 226 is a check valve that is oriented to allow air from the conduit 224 to pass out of the conduit 224 and not into the conduit 224. In some embodiments, the valve 226 is biased closed and configured to open when pressure in the conduit 224 reaches a magnitude corresponding to a predetermined pressure of the dunnage bag 222 (e.g., desired fill pressure). In some embodiments, the valve 226 is biased to open when the predetermined pressure in the dunnage bag 222 is in a range of 1 to 10 psi gage. In some such embodiments, the predetermined pressure is no greater than 5 psi gage.
In some embodiments, the valve 226 is a spring-loaded ball check valve. The magnitude of pre-loading of the spring 244 corresponds to a predetermined fill pressure in the dunnage bag 222. When the dunnage bag 222 is sufficiently inflated, back pressure in the conduit 224 provides a force on the ball that is sufficient to overcome the pre-loading by the spring 244 so that excess air is then vented through the valve 226 instead of filling the dunnage bag 222 beyond the predetermined fill pressure.
According to an exemplary embodiment, when the valve 226 is open, the valve 226 vents to atmosphere, which may include open air within or outside of the associated cargo container. In some embodiments, the valve 226 vents directly to atmosphere, while in other embodiments, the valve vents to another conduit that vents to atmosphere. In some embodiments, the valve may vent to a lower pressure manifold directed to a compressor for recirculation of the pressurized air in the pneumatic system.
Use of the valve 226 allows for the pressurized air to be communicated at supply pressures (e.g., 60 psi) well above the burst pressure (e.g., 15 psi) of the dunnage bag 222 because the valve 226 is automatically activated to release pressurized air once the dunnage bags 222 have been filled to the predetermined pressure (e.g., 2 to 3 psi). Accordingly, inflating the dunnage bags 222 with pressurized gas from the manifold 218 increases the speed at which the dunnage bags 222 may be inflated relative to inflation from a source supplying pressurized air at or proximate to a safe-inflation pressure (e.g., 6 psi or less) of the dunnage bags 222.
In contemplated embodiments, the valve 226 is a device other than a check valve, such as a pilot-operated ball valve, variable restrictor, directional-control valve, and/or another flow-control device. In some such embodiments, the valve 226 may be controlled directly as a function of pressure in the conduit, manifold, dunnage bag, or elsewhere in the system. In other such embodiments, the valve 226 may be controlled indirectly by a solenoid or other actuator that is operated as a function of pressure or another parameter, such as stress or strain, that may be related to pressure.
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In other embodiments, once the dunnage bags 222 are inflated the source 212 may be decoupled from the pneumatic system 210 and the dunnage bags 222 are closed off, such as by a check valve in the conduit 146 (see, e.g., check valve 422 as shown in
According to an exemplary embodiment, the station 220 includes a coupler 230 configured to allow for separation of pneumatic communication between the dunnage bag 222 and the manifold 218 (see also coupler 164 as shown in
In some embodiments, one or both of the connectors 232, 234 of the coupler 230 may include an integrated check valve. In some such embodiments, the check valves of the connectors 232, 234 are activated when the coupler 230 is disconnected in order to prevent air from passing through the connectors 232, 234 (see disconnected coupler 246 as shown in
A similar coupler 240, 242 may be used between the sources 212, 214 and the manifold 218. When either of the sources 212, 214 are disconnected from the manifold 218, then a check valve may be activated to prevent flow of pressurized air from the manifold 218. Connecting either source 212, 214 with the couplers 240, 242 may then hold open the associated check valves.
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When the evacuation assembly 216 is in operation, the directional-control valve 248 directs a flow of pressurized air from the source 212 (or another source) across an opening in the Venturi configuration 250 that is coupled to the manifold 218. Movement of air normal to the opening provides low pressure at the opening, which is communicated to the dunnage bags 222 through the conduits 224 and manifold 218. Accordingly, the Venturi configuration 250 draws air from the dunnage bags 222, rapidly and fully deflating the dunnage bags 222, which facilitates quick unloading of the associated cargo.
In other contemplated embodiments, an evacuation system includes a pump that provides a vacuum, such as a centrifugal pump or a positive-displacement pump, to actively suction air from the dunnage bags 222 through the conduit 224 and manifold 218. In some such embodiments, the manifold 218 is coupled to the intake of the same compressor that may be used to provide pressurized air (from the outlet thereof) to inflate the dunnage bags 222.
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In some embodiments, a pilot 324 from the check valve 322 is directed to a shutoff valve 326 that closes the conduit 320. The check valve 322 may also be configured to vent air that is not used in the pilot 324 to atmosphere. In some embodiments, the shutoff valve 326 is a ball valve. In other embodiments, the shutoff valve is a shuttle valve or another type of valve. The shutoff valve 326 may be used in conjunction with or in place of a coupler to disable the station (see, e.g., coupler 230 as shown in
In contemplated embodiments, the signal provided by the pilot 324 may be countered by a second signal associated with pressure in the dunnage bag or conduit. For example, if pressure in the dunnage bag or conduit exceeds the predetermined pressure, excess pressurized air will vent and the pilot signal will direct the shutoff valve 326 to close, shutting off the flow of air to the dunnage bag 318 from the manifold 314. However, if pressure in the dunnage bag 318 or conduit 320 falls below a second predetermined pressure (e.g., 0.5 psi less than the first predetermined pressure), then the second signal will direct the shutoff valve 326 to open. Operating the pneumatic system 310 based upon pressure in the conduit 320 may allow for use of standard dunnage bags with the pneumatic system 310.
According to an exemplary embodiment, the pneumatic system further includes a biased check valve 328 coupled to the manifold 314. When inflating the dunnage bags 318, as all of the shutoff valves 326 close, pressure on the manifold 314 will increase to a predetermined pressure at which the biased check valve 328 will open to provide a signal to turn off the source 312. The biased check valve 328 may also be configured to vent excess pressurized air to atmosphere. In some embodiments, the biased check valve 328 coupled to the manifold 314 is configured to initially open at a greater pressure than the biased check valves 322 coupled to the conduits 320 of the stations 316.
Referring to
Accordingly, an operator may set the valve 420 to a predetermined pressure for filling the dunnage bag 418. Once pressure in the dunnage bag 418 reaches the predetermined pressure, the valve 420 opens and vents additional air to the atmosphere. When all dunnage bags 418 coupled to the manifold 414 have been filled, an operator may turn off the source 424 of pressurized air and decouple the source 424 from the pneumatic system 410. In other embodiments the valve is coupled to the conduit (see, e.g., valve 226 as shown in
Although shown, according to the exemplary embodiments, for use with inflation of the dunnage bags, the present disclosure may be applied to a broad range of pneumatic control applications and inflation tasks, and may be used with various inflatable items. In some embodiments, a pneumatic system may be used to control rapid inflation of inflatable shelters, rafts, air mattresses, dirigibles, etc. In some embodiments, fluids other than air may be used and controlled by a system embodying technology described herein.
The construction and arrangements of the pneumatic system, as shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Components shown for use with some embodiments may be mixed and matched with other embodiments, such as the evacuation assembly 216 shown in