Convertible container for fluent or solid cargo

An intermodal cargo container capable of being quickly and easily converted between a solid storage mode and a fluent storage mode is disclosed. Shell sections adapted to be either removed from, or pivoted within, an outer container are provided to support an impermeable liner in the fluent storage mode. Elements of both the inner and outer container may be of conventional construction for surface transport or of lightweight construction suitable for air as well as surface transport.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to the field of cargo transport. More 
specifically, this invention is concerned with cargo containers that may 
be converted to carry a wide variety of material having different 
characteristics and densities. The present invention finds particularly 
useful application in the field of containerized cargo using so-called 
intermodal containers. It should be clear that the advantages of the 
invention are equally manifest in various types and sizes of containers. 
2. Background of the Invention 
Two of the major problems faced by the cargo industry were the desire to 
quickly transfer cargo from one mode of transport to another and the 
so-called "backhaul" or "deadhead" problem created when a carrier was 
forced to travel some distance empty, since he was not equipped to carry 
the type cargo available. 
In response to the growing demand for a simple method of transferring cargo 
from one mode of surface transport to another, intermodal containers have 
been developed. These containers are designed to meet International 
Standards Organization (ISO) specifications, and are generally 8 feet high 
by 8 feet wide by 10 to 40 feet long, in 10 foot increments. Generally use 
of this type of container has been with various means of surface 
transport, however, it has seen limited use in air transport. Recently 
lightweight containers of this type, specifically for air shipment, have 
become available. 
Backhaul difficulties arise when a carrier transports, for example, solid 
cargo in one direction and is then forced to make the return trip empty 
since only fluent materials are available for shipment. Some efforts have 
been directed toward converting these carriers from one type of cargo to 
another, however such systems require not only a substantial amount of 
idle time for the carrier during conversion, but also a large amount of 
freight depot storage at each end of the route for the necessary hardware. 
Frequently, an excess of one type of hardware is stored at one end of the 
route, while the need for the hardware is at the other. 
It has been suggested that these difficulties may be overcome by providing 
self-contained, convertible cargo containers. Typical prior efforts in 
this regard utilize, for example, a collapsable liner directly supported 
by the walls of the outer container and held in position by a bulky 
linkage assembly. Since such containers are generally intended for use by 
surface transport means, little effort appears to be directed toward 
minimizing weight and bulk. 
A related problem in the design of a convertible container is the different 
densities of solid and fluent cargo. Since fluent material, such as a 
liquid, is far more dense than solid cargo, a conversion design must 
compensate therefor by providing a smaller fluent container supported to 
evenly distribute the load. This factor is extremely critical in air 
transport where pressure of the liquid is accentuated by high acceleration 
forces during flight maneuvers. 
One object of the present invention is to provide an intermodal container 
that may be quickly and efficiently converted from one type of cargo 
storage to another using elements and hardware that are always stowed 
within the container. 
Another object of the invention is to provide a convertible container 
system wherein an inner, fluent material container may be removed and 
compactly stored so as to be efficiently transported by the carrier when 
not in use. 
Yet another object of the present invention is to provide a convertible 
container system whereby all of the hardware necessary for converting the 
container from solid to fluent storage will either move out of the way 
within the container or be mounted and dimensioned so as to be removable 
from several containers and nestable within a single container. 
It is another object of the invention to provide a convertible, intermodal 
container capable of utilizing the maximum allowable cargo density 
regardless of the type of cargo carried. 
Another object of the invention is to provide a container capable of 
holding solid cargo on one end and fluent cargo on the other end. 
A related object of the invention is to provide a convertible, intermodal 
container system wherein all elements and hardware necessary for 
conversion are carried with the transport, thus eliminating the necessity 
of destination storage. 
SUMMARY OF THE INVENTION 
The present invention overcomes the aforementioned problems and 
disadvantages by providing a standard or lightweight cargo container that 
may be easily and quickly converted from one storage mode to another. An 
inner, preferably cylindrical container supporting an impermeable bag or 
liner is positionable within an outer container to hold fluent material. 
This inner container is supported from the stable edges of the outer 
container, which in turn is locked to the aircraft floor in a known 
manner. The inner-container may be quickly removed or pivoted to a stowed 
position whereby the outer container may be used for solid cargo.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring first to FIGS. 1-2 an intermodal container, generally designated 
10, is shown. Container top wall 12, side walls 14, 16, bottom wall 18 and 
end walls 20, 22 (FIGS. 6, 7) respectively, may be of any well known 
lightweight construction, such as for example, fiberglass, skin/stringer 
arrangement, honeycomb material or corrugated light metal alloys. In FIG. 
1, container 10 is configured for carrying fluent material. As used 
herein, "fluent" is intended to encompass granular, powdery or gritty 
materials as well as liquids. In this configuration, a generally 
cylindrical, open ended container 30 is supported within container 10 by 
links or supports 32, 32', 32". Container 30 may be formed of two or more 
shell sections 34, 36. Sections 34, 36 may extend the full length of 
container 10 or may be divided into a plurality of axially extending 
segments. Such segments not only simplify handling during conversion, but 
also permit both fluent and solid cargo to be carried in the same 
container 10, as will be discussed in greater detail infra, with reference 
to FIG. 8. Shell sections 34, 36 are secured together by one or more 
removable pins 38 which extend through holes 40 in bosses 42 and flange 49 
(see FIGS. 6 and 7). Other, known means of providing an easily releasable 
connection could, of course, be used. 
Links or supports 32, 32', 32" are pivotally mounted by brackets 44 to the 
inside of top, side and bottom walls 12, 14, 16, 18 by pins 46. Note 
bracket 44 for link 32' is recessed into wall 18. Pins 46 may extend the 
entire length of container 10 or may be longitudinally divided into a 
plurality of segments which are complimentary in length to shell segments 
34, 36. In either arrangement pins 46 may be removable to permit withdrawl 
of links 32, 32', 32". Links 32 are also removably attached to shell 
sections 34, 36 by removable pins 48 passing through holes in bosses 47 
and flange 49 or any of a variety of well known easily removable coupling 
means. Links 32', 32" are removably attached to sections 34, 36 by 
aforementioned pins 38. With shell sections 34, 36 secured together and 
links 32, 32', 32" attached, container 30 serves to support one or more 
liners or bags 50, which may be formed for example, of rubber or other 
flexible, impervious material. Bag 50 will be discussed in greater detail 
infra, with reference to FIGS. 6-8. The end walls 20, 22 (FIGS. 6, 7) of 
container 10, or an auxiliary wall 52 (FIG. 8), serve as the end walls of 
container 30 and confine bag 50 therein. Of course, when required by 
higher pressure, e.g. liquified gases, dome-shaped end plates may be 
provided. 
A typical density range of solid cargo completely filling an intermodal 
container intended for air transport, dimensioned to ISO specifications of 
8 feet by 8 feet by 20 feet, is approximately 10-20 lb/ft.sup.3. In the 
fluent mode, a container 10, carrying an inner container 30 having a 
diameter of approximately 4 feet and filled with a liquid of approximately 
45-90 lb/ft.sup.3 density, exhibits an equivalent dry cargo density of 
approximately 10-20 lb/ft.sup.3. It is therefore clear that container 30 
could of course have other dimensions or be less than completely filled, 
depending on the density of the fluent cargo to be carried, that maximum 
gross weight of the container and the structural limits of the mode of 
transport concerned. 
When solid cargo is to be transported, container 10 may be quickly 
converted to that mode. Container 30 and bag 50 may be removed from 
container 10 by removing pins 38 and 48. For ease in handling, it may be 
desirable to separate the shell sections and/or segments prior to removal. 
After container 30 has been removed, links 32, 32" are pivoted in the 
direction of arrows A against the inside of walls 12, 14 and 16 of 
container 10. Brackets 54, adapted to accept a coupling such as pin 48, 
are provided to hold links 32, 32" in stowed position against walls 12, 14 
and 16. Link 32' is preferably removed from lower wall 18 and stowed 
against a side wall 14, e.g. by providing additional brackets (not shown) 
on one of links 32, or in some other convenient location. In this manner 
the bottom wall 18 is left clear so as to provide easier access to the 
interior of container 10 for loading by, e.g., a forklift. 
Shell sections 34, 36 are stacked or nested on one side of a container 10 
while bags 50 are stacked on the other, as shown in FIG. 2. In this manner 
all necessary hardware for fluent cargo is carried for backhaul with 
minimal loss of solid cargo transport capacity. Of course breakdown into 
smaller segments can improve stacking efficiency. 
Turning now to FIGS. 3-7 there is shown another embodiment of the invention 
wherein conversion from fluent (FIG. 3) to solid (FIG. 4) mode is 
accomplished by pivoting shell sections 34, 36 about pivot pin 60. As seen 
in FIG. 6, pin 60 may extend through holes 40 in bosses 42, so that shell 
sections 34, 36 may be used in either embodiment of the invention. 
However, other known pivot arrangements could be used if desired. Bosses 
42 are positions to mate with a permanent support bracket generally 
designated 62, which is made up of individual arms 64 carrying holes for 
pin 60. Slots 56 are provided in sections 34, 36 to accomodate arms 62. To 
convert this embodiment of the invention from fluent to solid mode, it is 
only necessary to remove pins 48 from links 32, 32'. Links 32 are then 
pivoted (arrows A) against the walls 14 and 16 of container 10 and held 
there by brackets 54 as discussed supra. Once again the lower link 32' is 
removed to provide a clear bottom wall or floor area for loading. Shell 
sections 34, 36 may then be pivoted to their stowed position (FIG. 4) and 
held there in any convenient manner, e.g., by providing additional 
brackets similar to brackets 54. 
As shown in FIG. 4, in an empty condition, bag 50 collapses and is held out 
of the way in any desired manner, e.g. by a longitudinally extending rod 
(not shown) releasably secured to shell sections 34, 36 and pressing bag 
50 upwardly along its length. FIG. 5 illustrates another possible storage 
position for bag 50. 
Bag 50 may be filled and emptied in a variety of ways depending on, e.g. 
the type of fluent material being carried and the equipment available for 
such purposes. Openings may be provided through the ends of bag 50, 
however, for purposes of illustration a top fill arrangement is shown. As 
shown in FIGS. 6-7, holes 70 may be provided at various locations through 
shell sections 34, 36. A flexible tube 72 which has been vulcanized or 
otherwise firmly secured to bag 50 is passed through hole 70 and is 
attached by any desired means to any one of a plurality of capped openings 
74 (only one shown) in upper wall 12. A similar tube (not shown) may be 
provided in a lower portion of container 30, to provide gravity discharge 
of the contents. Obviously, this latter tube would need to be disconnected 
prior to pivoting shell sections 34, 36 to their stowed position. Rigid or 
accordian-type fill tubes could also be used. 
FIG. 8 illustrates a slightly different arrangement of the invention 
whereby both fluent and solid cargo may be carried at the same time in the 
same container. An auxiliary wall 52 is provided to serve as an end wall 
for shortened container 30, which is created by moving less than all 
segments 34, 36 into fluent storage position. Of course a bag 50 of 
reduced length would be necessary for such an arrangement. Auxiliary wall 
52 could, for example, be stored at one end of container 10 when not in 
use. Although this divided version of the invention is illustrated with 
the embodiment of FIG. 3, it should be apparent that a similar version 
could be created with the embodiment of FIG. 1. 
It is clear that the instant invention provides an efficient and easily 
converted cargo container capable of great flexibility. In this way more 
efficient use of both the carriers time and dwindling fuel resources is 
provided. 
Variations and modifications will occur to persons skilled in the art 
without departing from the spirit and scope of the invention. Accordingly 
it is intended that the appended claims cover all such variations and 
modifications.