Container chassis bundling system

A container chassis bundling system uses permanently affixed clamps 14, 14a, 40, 42, 42a, or 42b, for example, placed on a container chassis 10 to interconnect container chassis into an integral stack of chassis. Usually, chassis are interconnected with corresponding twist-lock bayonets 18 and twist-lock receivers 12 between corresponding top surfaces of the chassis and either rail 42, 42a, or 42b or landing gear interconnections 14 or 14a between the rails on the bottom flanges of the other chassis. An axle clamp 40 may connect the axle of one chassis to the kingpin of another chassis. Rail clamps 42, 42a, or 42b may also be used to connect corresponding top surfaces.

TECHNICAL FIELD 
The present invention relates to a stack of container chassis and to a 
method for stacking and interconnecting container chassis for shipment, 
and more particularly, to an improved container chassis having permanently 
affixed means for interconnecting the chassis with others in a stack. 
BACKGROUND ART 
Traditionally, container chassis are loosely bundled by piling one chassis 
atop one another and interconnecting them with chains, straps, or other 
banding to temporarily hold the chassis in place. Such an operation is 
labor intensive and is hazardous to the operators. Furthermore, the 
integrity of the bundles is at question because it is difficult to 
interconnect the chassis as rigidly as desirable. This invention improves 
on the method for stacking and interconnecting container chassis, and 
greatly improves the off-loading of containers. The bundling material can 
cost as much as $500/bundle, and is sometimes discarded after each trip. 
The system of the present invention reuses the clamping materials. 
DISCLOSURE OF INVENTION 
A method for stacking and interconnecting container chassis for shipment 
includes positioning an inverted first chassis atop a base chassis so that 
the front of the first chassis aligns with the back of the base chassis 
and interlocking the two chassis with suitable connectors which are 
permanently affixed to at least one chassis. The interlocking connectors 
generally include at least one twist-lock bayonet on one chassis and a 
corresponding twist-lock receiver on the other chassis. The twist-lock 
bayonet is inserted into the twist-lock receiver to lock the two chassis. 
Alternatively, the interlocking connectors may include (1) a rail clamp on 
one chassis which is wrapped about and connected with a corresponding rail 
flange on the other chassis, (2) an axle clamp on one chassis which is 
interconnected with the kingpin of the other chassis, or (3) a landing 
gear cross-brace rail clamp. Bundles of two or more chassis may be made 
using the present method and apparatus simply by alternately laying 
chassis either top-to-top or bottom-to-bottom and interconnecting them 
with twist locks, rail clamps, axle clamps, cross-brace rail clamps, or 
some combination thereof. 
The system allows quick and easy interconnecting of chassis into an 
integral bundle which is readily transported. The invention allows for a 
standardized assembly of container chassis bundles and results in an 
efficient, strong assembly of the chassis for transshipment as an integral 
assembly. Accordingly, less labor is required in making and transporting 
the bundles. Materials are recycled at a significant economic savings. 
These novel features of the invention greatly increase the efficiency of 
shipping merchandise by container.

BEST MODE FOR CARRYING OUT THE INVENTION 
As shown schematically in FIG. 1, a stack of five container chassis 10 can 
readily be made by interlocking each chassis 10 with twist lock assemblies 
on the top of each chassis 10 and landing gear cross-brace rail clamps 14 
associated with the landing gear 16. The bottom container chassis 10 
receives an inverted chassis 10 which has its rear bolster abutting the 
front bolster of the base. The second chassis is inverted so that its 
wheels 66 project upwardly, and so its landing gear 16 extends upwardly. 
Four twist-lock bayonets 18 (two on the ends of each rear bolster 21) 
couple with twist-lock receivers 12 to secure the chassis together. A 
third container chassis 10 is then positioned above the second immediately 
above the first chassis so that its wheels 66 are essentially in vertical 
alignment with those of the first chassis. That is, this third chassis has 
its bottom in close proximity to the bottom of the second chassis and is 
substantially aligned with the first so that the front bolster 220 of the 
third chassis aligns with the rear bolster 21 of the second chassis. The 
second and third chassis are then interconnected by landing gear 
cross-brace rail clamps 14. Similarly, a fourth chassis is positioned atop 
the third in analogous fashion to the positioning of the second atop the 
first. Finally, in the five-high stack, as shown, a fifth chassis is 
positioned above the fourth analogously to that of the third chassis atop 
the second. A secure bundle is made which can be transported safely as a 
unit. The entire stack may be lifted as a unit, thereby easing handling of 
the stack. 
The first and second chassis are interconnected at the respective front 
bolsters 20 with twist-lock receivers 12 and twist-lock bayonets 18, as is 
more clearly shown in FIG. 2. The twist-lock bayonets 18 are already 
positioned on the ends of the rear bolster of the container chassis for 
receiving a container for ordinary transit. The structure of the chassis 
is modified, as shown in FIG. 2, by adding a pivotable twist-lock receiver 
12 on the front bolster 20 of the chassis or by building a twist-lock 
receiver directly into the front bolster 20, if feasible (not shown). The 
pivotable twist-lock receiver 12 is positionable either in a substantially 
horizontal plane, as shown in FIG. 2, or in a substantially vertical 
plane, pivoting around the pivot 22 to allow the connector pin 24 to be 
used to receive a container against the front bolster 20 of the chassis 
10. That is, the receiver 12 flips out of the way when the chassis 10 is 
used to transport a container. As shown in FIG. 7, the twist-lock 
receivers 12 and twist-lock bayonets 18 are positioned near the ends of 
the bolsters 20 and 21 at the corners of the chassis. 
A typical landing gear cross-brace rail clamp 14 is shown in FIG. 3, where 
the cross-member 26 of the landing gear supports 28 includes clamp 32 
which engage the rails 30 of the next adjacent chassis 10 in the stack. 
Each clamp 32 includes corresponding rail-engaging flanges 34 and 36, 
which are interconnected by a latching device, such as a trunnion 38. The 
trunnion 38 allows tightening of the flanges 34 and 36 about the flange 52 
of the chassis rail 30. That is, by turning the threaded shaft of the 
trunnion 38, the corresponding flanges 34 and 36 of the clamp 32 may be 
moved together so that they engage and interlock with the flanges 52 of 
the rails 30. A simple and secure interconnection is readily achieved. 
Thus, with a plurality of corresponding twist-lock bayonets 18 and 
twist-lock receivers 12, and landing gear cross-brace rail clamps 14, a 
stable and integral stack of chassis 10 may be easily constructed for 
transporting the empty chassis as a bundle. The necessary apparatus for 
making the sturdy, durable, and dependable interconnection of the chassis 
10 is contained on each chassis and does not interfere with normal use of 
the chassis for hauling containers. Use of this bundling system does away 
with the cumbersome and labor-intensive task of interconnecting the 
chassis with chains, cables, or other means. The present invention 
provides a standardized location for and coupling between container 
chassis to allow durable, stable, and sturdy interconnection. With this 
invention, it is believed that a stack of five chassis may be used safely, 
while presently, with the existing cable and chain system, only a 
four-high stack may be legally transported. The ability to bundle five 
chassis at once will improve their transshipment, especially when the 
stack can be handled as a unit. 
As shown in FIG. 4, there are alternate embodiments for the inteconnection 
of chassis 10a. As with the stack of FIG. 1, however, five chassis 10a are 
interconnected by placing them in an alternating, inverted sequence, as 
previously described. Here, however, twist-lock receivers 12 and 
twist-lock bayonets 18 are not used, but instead, axle clamps 40 and rail 
clamps 42 are used. In the schematic of FIG. 4, the landing gear 16 for 
all but the bottom chassis have not been shown. Also, the standard 
twist-lock bayonets 18 (FIG. 1) have been omitted. 
A typical rail clamp 42 is shown in FIG. 5, where the clamp 42 includes a 
pivotable arm mounted to a plate 46 on the web 48 of a rail 30 of a first 
chassis 10a. The arm 44 is sufficiently long so that an ear 50 at the far 
end of the arm 44 can engage the flange 52 of the corresponding rail 30 
for the next chassis 10a in the stack. A corresponding retainer 54 is 
interconnected to the arm 44 with a chain 56 allowing gross adjustment 
since the receiver 54 may slide on the chain 56 in one position and may be 
locked in a second position. A screw 58 at the arm 44 allows fine 
adjustment of the receiver 54 about the flange 52 of the rail by drawing 
the chain 56 relative to the arm 44. The screw 58 is turned with a handle 
60 to draw the screw 58 inwardly to tighten the receiver 54 against the 
flange 52. 
A typical axle clamp 40 is shown in FIG. 6, where the clamp 40 includes a 
saddle 62 on the kingpin 63 of one chassis. The saddle 62 engages the axle 
64 of the associated chassis between the tires 66. A chain 68 can then be 
tightened around the axle 64 and connected to the saddle 62 so that the 
axle 64 engages the saddle 62 and is held securely. 
FIG. 8 shows an alternative clamp 42a of the present invention. As with the 
rail clamp 42 of FIG. 5, this rail clamp, 42a is pivotably connected to 
the web 48 of a lower rail 30 of a container chassis with a plate 46 that 
is welded or bolted to the web 48. The preferred rail clamp 42a has an arm 
70 which has a flange-engaging, forked end 72. The arm 70 also includes a 
pivotal connection 74 for a bearing member 76 which is pivotally connected 
with a receiving arm 78. The receiving arm 78 clamps to the flange 52 with 
a corresponding flange-engaging end 80. The two flange-engaging ends 72 
and 80 are quickly interconnected about the flange 52 and are held in 
position by the over-center clamp lever effect of the rail clamp 42a 
design. In operation, the flange-receiving end 72 of the arm 70 is 
positioned about the flange 52, while the flange-receiving portion 80 of 
the receiving arm 78 is loosely positioned about the respective flange. 
Then, the entire clamp 42 is tightened by pivoting the bearing member 76 
about its pivotal connection 74 on arm 70. Thus, a very quick and simple 
clamp is provided. When not in use, the entire rail clamp 42a pivots 
downwardly against the web 48 of the corresponding container chassis. 
Preferably, although not shown in this combination, a landing gear 
cross-brace rail clamp 14 and a rail clamp 42 are used together to 
interconnect chassis. This combination ensures a stable bundle and is the 
most universally applicable. Since there are many chassis designs (each 
just slightly different from the others), this combination of rail clamps 
seems to provide the greatest degree of flexibility. 
A highly preferred landing gear cross-brace rail clamp 14a is shown in FIG. 
9. A beam 82 extends between the landing gear supports 28 and is bolted to 
the landing gear brace attachment ears 83. The beam 82 generally is a 
hollow rectangular member having two telescoping segments interconnected 
to span between the supports 28. Stops 84 are fabricated onto the beam 82 
near its ends. These stops 84 are outside the flange of the overlying 
chassis. The beam 82 supports sliding clamps 86 which can be moved so that 
a dog 88 overlies the flange 52 on the overlying chassis. A hook 90 may 
then be positioned over the opposite end of the flange 52 and a toggle 92 
may be flipped to secure the clamp 86 to the rail 30. 
For ease of installation and to accommodate different chassis widths, the 
beam 82 usually comes in separate sections so that the end tabs can be 
welded to the beam after being bolted to the supports 28. 
A highly preferred rail clamp 42b is shown in FIG. 10. This clamp 42b is 
pivotally mounted to the web 48 of a bottom rail 30 so that the body 94 of 
the clamp 42b can extend above the flange 52 of the overlying rail 30. 
The body 94 includes an inwardly projecting terminal portion 96 to overlie 
the rail flange 52 of the overlying chassis rail. A latch 98 mounted 
through a hole in the body 94 extends across the flange 52 to engage the 
opposite side of the flange 52 with a hook 100. A toggle 102 can be thrown 
to draw the hook 100 tight and a locking pin (not shown) can then be 
placed in the toggle 102 to keep it latched. When the clamp 42b is not in 
use to interconnect two chassis, it can be pivoted to extend outwardly 
from the web 48 below the flange and can be latched down to avoid any 
interference with use of the chassis. 
FIGS. 1 and 4 show lifting frames 110 and 120, which can be connected to 
the upper chassis in the bundle to lift the entire bundle as a unit. 
While preferred embodiments of the present invention have been shown and 
described, those skilled in the art will recognize modifications which 
might be made to the invention without departing from its inventive 
concept. For example, any combination of the interconnection devices can 
be used to securely fasten the adjacent tops and bottoms of adjacent 
chassis. Therefore, this description and the following claims are intended 
to be construed as liberally as possible to cover the concept of the 
invention, and the claims should not be limited to the specific 
embodiments unless such limitation is necessary in view of the pertinent 
prior art.