High-cube top lift cargo carrier structure

A cargo carrier liftable by, a lift element of a vertical mover includes a floor, a roof, a pair of parallel side walls, and first and second end walls, at least one of the side walls and end walls including a opening to permit the entry and exit of cargo. A plurality of low profile floor supports extend between the side walls to increase container capacity without increasing exterior dimensions of the container. A plurality of lift pockets are fixed to the side walls adjacent the roof, each lift pocket including a back plate and a guide plate attached to lie in parallel contiguous relationship to the side wall and in spaced apart parallel relationship to the back plate to define a cavity therebetween. The guide plate includes an aperture therethrough to allow acceptance of the lift element, the guide plate aperture including opposing edges having upwardly converging linear segments for guiding the lift element into engagement with the lift pocket, the upper edge of the aperture defined by an arcuate segment intersecting the upwardly converging linear segments. The back plate lower portion is outwardly inclined for encouraging disengagement of the lift element from the guide plate aperture upon downward movement of the lift element with respect to the cargo carrier.

BACKGROUND OF THE INVENTION 
This invention relates generally to cargo carriers such as trailers, 
intermodal containers, and the like employed in the transportation of 
goods. The invention particularly relates to cargo carriers made 
principally or wholly from aluminum alloy extrusions and plates. 
In recent years, there has been growing interest in developing intermodal 
cargo containers suitable for transportation by truck, rail, or ship. With 
the dramatic increase in import and export trade experienced worldwide, 
the demand for such cargo containers has steadily increased. There has 
also been a steady demand that the intermodal containers, as well as 
trailers, be designed so as to have maximum volume capacity yet have 
outside dimensions within the laws and regulations applied to trailers and 
containers when they are being transported over the road by truck. 
Many cargo carriers suitable for multi-mode transport of cargo have 
recognized standard dimensions, structural features that minimize handling 
problems, and allow for stacking of containers. However, there exist a 
number of different and changeable standards. For example, in recent 
years, due to the relaxation of the permitted width dimension allowed on 
over-the-road truck trailers, some attention has been directed to the 
construction of increased width containers to increase container capacity 
as disclosed in U.S. Pat. No. 4,844,672, and increased width trailers as 
disclosed in U.S. Pat. No. 4,904,017. 
Another possible way for increasing cargo carrier capacity while retaining 
the outside maximum dimensions standardized by the industry regulations is 
by increasing the vertical height dimension of the interior of the cargo 
container. For example, the vertical height of conventional I-beam floor 
supports, as well as the thickness of wood flooring attached to the floor 
supports, can be reduced to increase the capacity of the cargo carrier. 
However, the structural requirements for supporting a defined load within 
cargo carriers does not permit substantial decrease in floor thickness 
using conventional materials or structures. 
Inasmuch as cargo carriers, particularly intermodal containers, can on 
occasion be exposed to sea transport, it is important that any 
dissimilarity in metals be avoided in order to reduce any galvanic 
degradation of the cargo carrier. As is part of the desire to maximize the 
volume of such cargo carriers, there is also a desire to maximize the 
vertical inside height by providing a floor structure which is as thin as 
possible while time retaining the necessary strength required for the long 
duty life typically experienced by such cargo carriers. 
These factors have led the inventors to focus attention on adopting a new 
floor structure, preferably made entirely of aluminum alloy, which would 
have sufficient strength and durability, and could be used on all types of 
cargo carriers including trailers and intermodal containers. A further 
object of the new floor structure is to provide a design which is suitable 
for use in cargo carriers employing a wide variety of structural elements 
taken from containers other than of aluminum alloy plate construction. Of 
particular interest was a desire to arrive at a construction which would 
permit easily repeatable assembly of cargo carriers even under close 
tolerance restrictions. 
With the dramatic increase in import and export trade experienced 
worldwide, the demand has also steadily increased for cargo carriers, 
including both trailers and containers, having common features which would 
permit top handling of the cargo carrier by a common means. There has also 
been a steady demand that the cargo carriers be designed so as to have 
lift pockets which only minimally intrude into the interior volume of the 
cargo carriers. 
These factors have led the inventors to focus attention on adopting a new 
lift pocket structure which would have sufficient strength and durability, 
and could be used on all types of cargo carriers including trailers and 
intermodal containers for simple engagement with pin, or pin and shoe, 
lift mechanisms. A further object of the new lift pocket structure is to 
provide a design which is suitable for use in cargo carriers employing a 
wide variety of structural elements taken from containers and trailers 
having other than aluminum alloy plate construction. 
Accordingly, an object of the present invention is to provide a cargo 
carrier having substantially increased usable internal space through 
utilization of a novel floor structure having minimum vertical dimensions 
while retaining the necessary strength and providing the necessary lift 
pocket structure to permit stacking of the cargo carrier and contents in 
the conventional manner. Another object of the present invention is the 
use of such a novel floor structure together with a novel lift pocket 
structure in a cargo carrier having other volume maximizing features to 
achieve a very large cubic volume capacitor. 
SUMMARY OF THE INVENTION 
A cargo carrier in accordance with the present invention encloses cargo 
within a compartment defined generally by a floor, a roof, a pair of 
parallel side walls, and first and second end walls. At lease one of the 
side walls and end walls includes an opening to permit the entry and exit 
of cargo from the enclosed space. The interior of the cargo container is 
maximized in the vertical direction by incorporating a floor comprising a 
plurality of low profile floor supports extending between the side walls. 
The plurality of floor supports are generally substantially uniformly 
distributed throughout the entire length of the floor. 
In the preferred embodiment, the side walls comprise a plurality of 
aluminum alloy plates assembled side by side. A plurality of aluminum 
stiffener panels overlie and join adjacent sides of the aluminum alloy 
plates sealing the enclosed compartment against the outside environment. 
The side wall construction and joining stiffener plates is similar to that 
construction discussed in U.S. Pat. Nos. 4,904,017, 4,685,721, 5,066,066 
and 5,122,099. 
A cargo carrier in accordance with the present invention also includes a 
plurality of box-like coupling means for coupling the cargo carrier in 
stacked relation to other cargo carriers of similar construction. 
Preferably, such box-like , coupling means are constructed of 
high-strength cast aluminum alloy when used in an all-aluminum 
construction in accordance with the present invention. Of course, suitable 
cast steel or other metal can be employed in the appropriate circumstance. 
The box-like coupling means are generally employed with stacking frames. 
The box-like coupling means are generally arranged on both the top and 
bottom of a container, but can be included only on the top of a trailer. 
In one embodiment intended merely for stacking on top of other containers, 
the box-like coupling means are only provided at the floor level of the 
container and no stacking frames are provided. It will be appreciated that 
top-handling of such a container is to be discouraged, or alternative 
means must be provided to permit such top-handling. 
In accordance with the present invention a cargo carrier can include lift 
pockets at the juncture of the top and side wall, and preferably at the 
top of an intermediate frame post, to facilitate various lift attachment 
devices. The lift pockets can be positioned bilaterally symmetric with 
respect to each other, with two lift pockets on one side wall being 
matched by correspondingly positioned pockets on the opposite side wall. 
In addition, pairs of lift pockets are positioned equivalent distances 
from the center of mass of the cargo carrier to reduce problems with 
differential forces applied to lifting mechanisms engaged into the lift 
pockets to move the cargo carrier. 
The top lift pockets are preferably formed by the combination of a back 
plate and a guide plate formed to define a guide plate aperture. The guide 
plate aperture preferably comprises upper edge defined by an arcuate or a 
semicircular segment. The ends of the arcuate or semicircular segment join 
to an opposing pair of diverging edge segments spreading apart in a 
downward direction, the diverging segments being configured to guide an 
upwardly moving lift element into engagement with the lift pocket. The 
lift pocket is dimensioned to accommodate insertion of a lift bolt or pin 
which can be connected to a lift shoe. The lift bolt can be connected to a 
crane, spreader, mover or some other device capable of lifting the 
container. Various positions of lift pockets are contemplated, as well as 
differing numbers of lift pockets, as needed. 
Of particular interest is the floor which is designed to maximize the 
interior dimension of the cargo carrier. In a first embodiment the floor 
comprises a pair of spaced parallel C-shaped channel members situated so 
as to have the C's opening toward each other. A plurality of floor panels 
are situated contiguously to each other in a common plane defined by the 
pair of C-shaped channel members. Each of the floor panels comprises a 
unitary member, preferably constructed of a high-strength aluminum alloy, 
the floor panel including a pattern of webs and flanges defining parallel 
ducts and channels. The ends of the ducts and channels are received in the 
C-shaped channel members with the ducts and channels arranged 
perpendicularly to the bight of the C-shaped channel members. Fastening 
means are provided for joining the plurality of floor panels to the 
C-shaped members preferably by passing through contiguous portions of the 
webs and flanges of the floor panels and one or more of the legs of the 
C-shaped channel members. 
In a second embodiment the floor comprises a plurality of spaced apart 
floor supports with each floor support consisting essentially of a pair of 
uniformly spaced apart vertical members having upper and lower ends, and a 
horizontal member joining the lower ends of the two vertical members to 
form in cross-section a U-shape. Reinforcing means in the form of bars or 
thickened portions are provided for reinforcing the horizontal member 
joining the lower ends and forming the bight of the U-shape. Flanges 
extend outwardly from the tops of each of the vertical members. The length 
of the vertical members is defined to be less than the horizontal distance 
between the vertical members of each support element, permitting the floor 
to occupy a minimum vertical space and increasing the internal capacity of 
the cargo container as compared to cargo containers having floors 
supported by conventional I-beams. It will be appreciated that it may also 
be possible to achieve a similar effect by fabricating H-beams having 
dimensions suitable for use as floor supports in a minimum vertical space 
floor as previously disclosed. 
The plurality of floor panels, and floor supports previously discussed 
generally form a first layer or subfloor over which is added a second 
layer comprising a plurality of longitudinally-extending elements situated 
parallel to side walls and fixed to the plurality of floor panels or floor 
supports. While the longitudinally-extending elements forming the upper 
second layer of the floor can be wood flooring strips or other similar 
material, an all-aluminum construction can be achieved by employing 
extruded aluminum members. Typically, these strips are attached by screws, 
bolts, or other conventional fasteners to the uppermost surfaces of the 
first layer. The second layer can be added over the first layer either 
before or after attachment of the base rails of the parallel side walls. 
The floor construction of the present invention leads to a reliable 
assembly which, if desired, permits preconstruction of the floor and side 
walls separate from each other followed by the co-joining of the side 
walls to the already-constructed single layer floor to be followed by the 
addition of the floor second layer, a roof structure, and the like to 
complete the container. Cargo carriers in accordance with the present 
invention achieve a desired volume capacity by minimizing the floor 
thickness while retaining the necessary floor strength. When an 
all-aluminum construction is employed, the container is well adapted for 
long life inasmuch as galvanic degradation of the container is avoided. 
Further, the residual value found in an all-aluminum container at the end 
of its duty life is substantial inasmuch as the container as a whole is 
easily recycled. 
One feature of the present invention is the use of a low profile floor 
structure as described. The vertical dimension of such floor structure is 
minimized to permit a maximizing of the internal volume capacity of the 
cargo carrier enclosed compartment. Another feature of the present 
invention is the use of lift pockets which include an arcuate or 
semicircular segment joined to an opposing pair of diverging edge segments 
spreading apart in a downward direction. The diverging segments 
advantageously guide an upwardly moving lift element into engagement with 
the lift pocket. 
Other feature and advantages of the present invention become apparent to 
those skilled in the art upon consideration of the following description 
of the preferred embodiments exemplifying the best mode of carrying out 
the invention as presently perceived. The detailed description 
particularly refers to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A cargo carrier 10 in accordance with the present invention is defined 
generally by a floor 12, a roof 14, a pair of parallel side walls 16 and 
end walls 18, at least one of which includes an opening 20 to permit the 
entry and exit of cargo. Suitable door structure (not shown) is of course 
provided to close the opening 20. The opening 20 is defined generally by 
the edges 22 of the side wall 16, a header 24, and a sill 26 underlying 
the threshold. 
The floor 12 extends from the rear sill 26 through the entire length of the 
cargo carrier 10 and can be of generally uniform construction of the type 
hereinafter discussed. Alternatively, a forward portion of the container 
can include strengthening features in a coupler area 28 and over a support 
dolly area 30, which can include a gooseneck tunnel, depending upon the 
use to which the cargo carrier will be put. 
In a first embodiment, the floor 12 is generally composed of a pair of 
spaced parallel C-shaped channel members 32 which open toward each other 
in confronting relationship, of which only one is shown in FIG. 1. A 
plurality of panels 34, shown only in generally in FIG. 1, and shown in 
greater detail in FIG. 3, extend from side to side of the trailer. Each of 
the panels 34 comprises a unitary member including a pattern of webs and 
flanges shown in somewhat more detail as panel 34' in FIG. 1, it being 
understood that all the panels 34 are of similar construction with the 
webs and flanges of the panels forming a series of parallel ducts and 
channels the ends of which are received in the C-shaped channel members 
32. The plurality of panels 34 taken together form a first layer 36 of the 
floor 12, namely, the layer 36 lying in the plane of the C-shaped channel 
members 32. 
The first layer 36 supports a second layer 38 which generally comprises a 
plurality of elements 39 which extend longitudinally along the length of 
the cargo carrier. In the preferred embodiment, the longitudinal elements 
38 consist essentially of extruded aluminum members, but can also consist 
of wood flooring strips or other flooring elements best suited for the 
intended purpose of the cargo carrier. The first layer 36 is intended to 
have sufficient integrity and strength as to form a base upon which the 
container 10 can be supported by an appropriate running gear 40, including 
beams 42 which can contact and be coupled directly to a lower surface of 
the panels 34. The vertical thickness of the layers 36 and 38 are 
minimized to maximize the cubic capacity of the cargo carrier. 
The side wall 16 is illustrated to comprise a plurality of 
vertically-oriented panels or plates 44 which can be of various 
construction, but are preferably made of aluminum alloy plate of the type 
generally described in U.S. Pat. Nos. 4,685,721 and 4,904,017. The side 
wall 16 is shown in FIG. 1 to include a frame post 46 which can have at 
its upper end a box-like coupling member 48 of the type generally employed 
with intermodal freight containers such as that shown in U.S. Pat. No. 
3,085,707. Preferably, lift pockets as disclosed in greater detail in 
FIGS. 11 through 13 are provided, alternatively or additionally, at the 
top of the frame post 46. 
The roof 14 is constructed from a series of roof bows 50 extending 
laterally between the tops of the two parallel side walls 16. As shown in 
FIG. 2, the ends of the roof bows are generally supported by a top rail 52 
defining the upper margin of the side wall 16. An appropriate skin or 
cover 54 is stretched over the roof bows 50 and secured to an upper margin 
56 of the top rail 52 by appropriate fastening means. The top rail 52 can 
be seen in FIG. 2 to include a lower portion 58 which extends downward 
over the outside of an upper margin of panels 44. The panels 44 extend 
downward over the outside of an upper portion 60 of base rail 62. The 
panels 44 are joined together by joining stiffening members 64 in the 
usual manner for aluminum alloy plate trailers. 
In FIG. 2 it will be noted that the base rail 62 includes a lower portion 
having a pair of inwardly-directed flanges 66 and 68. The flanges 66 and 
68 act to capture the separate C-shaped member 32 which holds the ends of 
panels 34. As shown in FIG. 2, the upper layer 38 of the floor 12 
comprises a plurality of aluminum extrusion members 70 which can be of any 
of several suitable designs. In addition to the design illustrated, other 
designs which might be employed are disclosed by U.S. Pat. Nos. 4,266,381, 
and 4,631,891. 
The aluminum extrusion members 70 forming the upper layer 38 have a lower 
surface defined by a series of flanges 72 which are supported by the upper 
surface 74 of panels 34. The upper surface 76 of aluminum extrusion 
members 70 form the supporting surface for the goods to be carried by the 
cargo carrier 10. It will be seen from the detailed view of FIG. 3 that 
the flanges 72 and 76 together with webs 78 define a series of channels 
most of which open downwardly to confront the underlying lower layer 36 of 
the floor but some of which open upwardly. 
The lower layer 36 of panels 34 is also seen in FIG. 3 to comprise a 
plurality of webs 80 and flanges 82 and 83 which again define ducts 84 and 
channels 86. Each of the panels 34 is coupled to the adjacent panel 34 by 
a coupling means 88 running the length of each of the panels 34 for 
coupling contiguous panels together. Appropriate fastening means 90 are 
employed to fasten the upper floor portion 38 to the lower floor portion 
36. 
FIG. 4 shows the enlarged view of a base rail 62' which includes an upper 
flange 66' which is directed inwardly toward the center of the cargo 
carrier. The lower portion 65 of the base rail 62' is coupled to the bight 
33 of C-shaped channel 32 by fastener 92. Additional fasteners 94 attach 
the lower and upper legs 96 and 97 of the C-shaped channel 32 to a lower 
and upper flange 82 and 83 of panel 34, respectively. It will be 
appreciated that the first layer or subfloor 36 comprising the plurality 
of panels 34 and C-shaped members 32 can be pre-assembled as a unit. 
Thereafter the side walls 16 can be positioned adjacent the longitudinal 
edged of the subfloor. The C-shaped channel 32 is then attached to the 
lower portion 65 of base rail 62 by means of a plurality of fasteners 92 
passing through the bight 33 of C-shaped channel 32. 
In order to achieve a thin, low vertical height floor structure that 
maximizes internal volume of the cargo carrier 10, the floor 12 can 
alternatively be constructed as shown in FIG. 5 to comprise a first layer 
36 having a plurality of spaced apart low profile floor supports 134 which 
extend transversely between the side walls 16. The low profile floor 
supports 134 are substantially uniformly distributed along the entire 
floor 12 at a regular spacing. Typically the floor supports 134 are spaced 
apart between 6 inches to 15 inches, although greater or lesser spacing 
can be used depending upon contemplated weight carrying capacity of the 
cargo carrier. In a preferred embodiment, the floor supports are spaced 
about 8 inches apart. The floor second layer 38 supported by the floor 
supports 134 is defined in part by strips 136 which can comprise 7/8 inch 
thick interlocking hardwood strips running lengthwise of the cargo carrier 
10 and perpendicular to the floor supports 134. Of course, the floor 
surface can be configured to be formed completely from hardwood strips, 
metal strips, metal plates, other conventional floor materials, or any 
combination of floor materials. 
To position the floor supports 134 in fixed attachment relative to each 
other, each of the side walls 16 includes a longitudinally extending base 
rail 162 that defines the lateral outer margins of the floor surface layer 
38. As shown in FIG. 6, the base rail 162 is attached to side wall 16. The 
base rail 162 has a lower outside flange 140 defining the lower margin of 
the side wall 16. A lower vertical portion 142 includes an inside surface 
confronting and joining end joining means 144 described in greater detail 
in connection with FIG. 8. An upper portion 146 of side rail 162 comprises 
an inwardly directed flange which defines the outer margins of the upper 
layer 38 of floor 12. 
The low profile floor supports are shown in greater detail in cross-section 
in FIGS. 7, 8, and 9 to comprise a pair of uniformly spaced apart vertical 
portions 148 and 150. A horizontal member 152 unitarily joins the vertical 
portions 148 and 150 to form in cross-section a very broad, shallow 
U-shape. Flanges 154 and 156 extend outwardly from the tops of each of the 
vertical elements 148 and 150, the flanges being periodically penetrated 
by fastening means 158 fastening the members 136 of the upper floor layer 
38 to the tops of flanges 154 and 156. 
In the embodiment shown in FIGS. 7 and 8, a reinforcing means 160 is welded 
to the horizontal portion 152 over substantially its entire length to 
provide a strengthening of the bottom of the U-shaped supports 134. The 
thickness "t" of the upper floor layer 38 is typically 7/8 inch while the 
thickness "T" of the low profile support elements 134 are less than or 
equal to about 11/2 inch. The width "W.sub.r " of the reinforcing portion 
160 is typically about 2 inches while the distance "W.sub.p " between the 
vertical portions 148 and 150 is approximately 3 inches. The width of the 
flanges "W.sub.f " is preferably about 11/4 inches. The preferred material 
for the formation of the low profile support elements is 7 gauge (0.171 
inch) high-tensile steel. 
The end joining means 144 are welded to the ends of the low profile support 
elements 134 and are shown in FIGS. 6 and 8 to extend above the flanges 
154 and 156. Each end joining means 144 is coupled to the base rail 162 by 
fasteners 92 which penetrate the support elements 144, the base rail 162, 
the aluminum alloy plates 44 collectively forming the sides 16, and the 
aluminum joining panel 64. 
In another embodiment shown in FIG. 9, the reinforcing means 160 of 
U-shaped floor support 134 is not separately formed, but integrally formed 
as a single extruded piece, with the horizontal member 152 appropriately 
thickened relative to vertical portions 148 and 150 to increase its 
strength and rigidity. The extruded U-shaped floor support 134 can be made 
of high strength aluminum but is preferably made of ASTM A-588-88 grade A, 
80,000 PSI minimum yield steel. The ends of the extruded floor supports 
134 can include joining means 144 as previously described in connection 
with FIG. 8. Alternatively, the ends of the extruded floor supports can be 
received in the inwardly directed C-shaped channel members 32 as 
previously discussed in connection with FIGS. 1, 2, and 4. Additional 
fasteners 94 can attach the horizontal member 152 and flanges 154 and 156 
to the lower and upper legs 96 and 97 of the C-shaped channel 32, 
respectively. 
In another embodiment shown in FIG. 10, low profile floor supports in the 
form of fabricated steel H-beam 234 preferably comprise pairs of plates 
forming each leg 290 and 292, and the vertical cross-member 294. The ends 
of the fabricated floor supports 234 are shown to be received in and 
welded to the inwardly directed C-shaped channel members 32 as previously 
discussed in connection with FIGS. 1, 2, and 4. The ends of the fabricated 
floor supports 234 can alternatively include joining means 144 as 
previously described in connection with FIG. 8. 
By utilizing a floor structure in accordance with the present invention, it 
is possible to achieve an interior vertical dimension at the door opening 
and throughout the interior of the cargo carrier of 110 inches. By using 
the thin side wall structure of joined aluminum plates, the interior width 
dimension can approach or equal 101 inches. In certain preferred 
embodiments, the overall length of the cargo carrier can approach 53 feet, 
thereby defining a substantially obstruction-free volume of exceptionally 
high cubic volume capacity for a cargo carrier, whether trailer or 
container. 
Transport of cargo carriers having low profile floor supports in accordance 
with the present invention can be facilitated by provision of various lift 
attachment devices. As illustrated generally in FIG. 11, the cargo carrier 
10 is provided with top lift pockets 170. The lift pockets 170 are 
provided in sets of four pockets. The pockets 170 are positioned 
bilaterally symmetrically with respect to each other, with two pockets on 
one side wall 16 being matched by correspondingly positioned pockets on 
the opposite side wall. In addition, pairs of pockets are typically 
positioned equivalent distances from the center of mass of the cargo 
carrier 10 to reduce problems with differential forces applied to lifting 
mechanisms hooked into the lift pockets to move the cargo carrier 10. 
The top lift pocket 170 is shown in more detail in FIGS. 12 and 13. As 
shown in those figures, the top lift pocket 170 is formed by the 
combination of a back plate 176 and a guide plate 174 formed to define a 
guide plate aperture 172. The guide plate 174 is situated to lie in 
parallel contiguous relationship to the side wall 16 and in spaced apart 
parallel relationship to the back plate 176 to define a cavity 177 
therebetween. The guide plate aperture 172 includes opposing edges 180 and 
182 having upwardly converging linear segments 184 and 186 for guiding the 
lift element into engagement with the lift pocket 170. Each lift pocket 
170 further comprises an upper edge 185 defined by an arcuate segment 
intersecting the upwardly converging linear segments 184 and 186 of the 
guide plate opposing edges 180 and 182. The back plate 176 further 
comprises a lower, outwardly inclined portion 188 for encouraging 
disengagement of the lift element from the guide plate aperture 172 upon 
downward movement of the lift element with respect to the cargo carrier 
10. 
The top lift pocket 170 is dimensioned to accommodate insertion of a lift 
shoe 212, connected to a lift bolt 210. The lift bolt 210 can be connected 
to a crane, spreader, mover or some other device capable of lifting the 
carrier 10. As will be appreciated by those skilled in the art, it is not 
necessary to use four lift pockets 170 located at the corners of the cargo 
carrier 110. Instead, alternate positions of lift pockets are 
contemplated, as well as differing numbers of lift: pockets, as needed. 
Although the invention has been described in detail with reference to the 
illustrated preferred embodiment, variations and modifications exist 
within the scope and spirit of the invention as described and as defined 
in the following claims.