Container coupling tool

A container coupling tool including a tool body having a flange and positioning protrusions provided on top and bottom of the flange. The tool body is formed with a bore extending therethrough from the top surface of one of the protrusions to the bottom surface of the other. A rotary shaft is received in the bore and has at its top and bottom ends top and bottom cones. Also, handle is inserted in a hole formed in the tool body and is coupled to the rotary shaft. The tool body is formed with a stopper hole opening to the bottom of the flange and communicating with the bore. A stopper having a stopper pin is vertically movably inserted in the stopper hole. The rotary shaft is provided on its outer periphery with engaging projections adapted to oppose the stopper pin in the circumferential direction of the rotary shaft when the stopper pin is received on the bottom end of the stopper hole with the tool body used in an upside down position , thereby preventing the rotary shaft from rotating toward a position where one of the top and bottom cones disengages.

BACKGROUND OF THE INVENTION 
This invention relates to a container coupling tool for coupling containers 
laid one on another. 
Shipping containers are laid in many tiers on a ship and transported. If 
they were simply laid one on another, they might collapse when the ship 
rolls and pitches on the water. Thus, each container is coupled to the 
containers immediately above and below by container coupling tools. 
One known container coupling tool comprises a tool body having top and 
bottom protrusions which can snugly fit in holes formed in container 
corner fittings. The tool body is formed with a bore extending from the 
top face of the top protrusion to the bottom face of the bottom 
protrusion. A rotary shaft is rotatably inserted in the bore. A top cone 
and a bottom cone are secured to the top and bottom of the rotary shaft 
over and under the top and bottom protrusions. By pivoting the handle, the 
top and bottom cones are turned together with the rotary shaft between two 
positions where they engage and disengage from the upper and lower 
containers, respectively. 
To couple two containers together with such a container coupling tool, the 
handle of each coupling tool is pivoted to turn the rotary shaft to the 
position where the entire top cone is inside the perimeter of the top 
protrusion. In this state, the top cone of each coupling tool is inserted 
into the hole of the respective bottom corner fitting of a container hung 
in the air by e.g. a lifting spreader. Then, with the top cone received in 
the corner fitting, the handle is pivoted to turn the rotary shaft to the 
position where the top cone engages in the corner fitting hole and the 
entire bottom cone is inside the perimeter of the bottom protrusion. The 
coupling tools are thus coupled to the container. 
The container is then placed on another container by inserting the bottom 
protrusion into the respective top corner fitting holes of the lower 
container, and the handle is pivoted to turn the rotary shaft to the 
position where both ends of the bottom cone engage in the respective 
corner fitting hole. 
When a container is hung in the air with the coupling tools of this type 
coupled to its bottom, if the handle of any coupling tool is turned 
inadvertently by e.g. colliding against an object, its top cone may 
disengage and the coupling tool may drop from the container. 
In order to solve this problem, the container coupling tool disclosed in 
examined Japanese utility model publication 5-23514 has a locking means 
for preventing the top cone from turning to its unlocked position to 
prevent the dropout of the coupling tool. 
In order to prevent undue turning of the top cone when the coupling tool is 
used either upside up or down, the locking means are made up of a large 
number of parts. Assembling such a coupling tool is very troublesome and 
its manufacture is costly. 
An object of this invention is to provide a container coupling tool which 
can reliably keep the topside cone engaged and which is small in number of 
parts and thus easy to assemble. 
SUMMARY OF THE INVENTION 
According to this invention, there is provided a container coupling tool 
comprising a tool body having a flange and positioning protrusions 
provided on top and bottom of the flange. The tool body is formed with a 
bore extending therethrough from the top surface of one of the protrusions 
to the bottom surface of the other. A rotary shaft is received in the bore 
and has at its top and bottom ends top and bottom cones. A handle is 
inserted in a hole formed in the tool body so as to open to the outer 
periphery of the flange and is coupled to the outer periphery of the 
rotary shaft. The top and bottom cones can be detachably engaged in holes 
formed in corner fittings of containers by pivoting the handle. The tool 
body is formed with a stopper inserting hole opening to the bottom of the 
flange and communicating with the bore. A stopper vertically movably 
inserted in the stopper inserting hole and has its inner end opposed to 
the bore and supported so that when the stopper moves down by gravity, the 
stopper partially protrudes outwardly from a bottom opening of the stopper 
inserting hole. Also, an engaging projection is formed on the outer 
periphery of the rotary shaft so as to oppose the inner end of the stopper 
in the circumferential direction of the rotary shaft when the stopper has 
moved down by gravity, thereby preventing the rotary shaft from rotating 
toward a position where the top cone disengages. 
Other features and objects of the present invention will become apparent 
from the following description made with reference to the accompanying 
drawings, in which:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
An embodiment of this invention is now described with reference to the 
drawings. 
As shown in FIGS. 1-3, a coupling tool body 1 has a flange 2 to be disposed 
between two stacked containers. Positioning protrusions 3a, 3b are 
provided on the top and bottom of the flange 2. 
The protrusions 3a and 3b are substantially rectangular and have arcuate 
ends. The protrusions 3a, 3b are sized so as to fit snugly in holes b 
formed in corner fittings B of containers A1, A2 (FIG. 3A). 
The coupling tool body 1 comprises right and left members 1a, 1b coupled 
together by bolts 4 and nuts 5. The coupling tool body 1 has a bore 6 
extending therethrough from the top face of the top protrusion 3a to the 
bottom face of the bottom protrusion 3b. The bore 6 has a large-diameter 
portion 7 at its axial center. Communicating with the large-diameter 
portion 7 is a hole 8 in the shape of a fan having its center on the axis 
of the bore 6 and opening to the outer periphery of the flange 2. 
A rotary shaft 9 is inserted in the bore 6. A handle 10 is inserted in the 
hole 8 with its inner end coupled to an intermediate portion of the rotary 
shaft 9 and its outer end protruding from the hole 8. 
A top cone 11 and a bottom cone 12 are secured to the top and bottom of the 
rotary shaft 9 over and under the top and bottom protrusions 3a, 3b, 
respectively, so as to be rotatable relative to the protrusions 3a, 3b, 
respectively. 
The top and bottom cones 11, 12 are identically shaped and are wider at the 
central portion, tapering toward both ends, as viewed from the top. Also, 
each cone 11, 12 has inclined surfaces 13 so that its vertical height 
decreases gradually toward both ends. 
As shown in FIG. 3B, the handle 10 can be temporarily locked by a temporary 
locking means 14 in three positions, i.e. a first position where it is 
against one side wall of the hole 8, a second position where it is against 
the other side wall of the hole 8, and a third position between the first 
and second positions. 
The temporary locking means 14 comprises a ball 16 as an engaging element 
and a resilient member 17 both mounted in a hole 15 extending radially 
outwardly from the large-diameter portion 7 such that the ball 16 is 
biased against the rotary shaft 9 by the resilient member 17. The ball 16 
is adapted to engage in one of three semispherical dents or detents 18 
forms so as to be, circumferentially arranged, in the rotary shaft 9 to 
temporarily lock the handle 10 in one of the three positions. 
When the handle is in the third position or position x, both the top and 
bottom cones 11, 12 are in their engaged positions where both of their 
ends protrude from both sides of the protrusions 3a, 3b. 
When the handle 10 is in the position y, top cone 11 is unlocked, that is, 
is entirely inside the perimeter of the top protrusion 3a as shown in FIG. 
6. On the other hand, the bottom cone 12 is in the engaged position with 
both of its ends protruding from the perimeter of the bottom protrusion 
3b. 
When the handle 10 is in the position z, the bottom cone 12 is unlocked, 
that is, is entirely inside the perimeter of the bottom protrusion 3b as 
shown in FIG. 4. On the other hand, the top cone 11 is in the engaged 
position with both of its ends protruding from the perimeter of the top 
protrusion 3a. 
Now referring to FIGS. 1 and 3, the coupling tool body 1 is formed with a 
hole 19 opening in the top and bottom surfaces of the flange 2. A stopper 
21 is mounted in the hole 19. 
The hole 19 is a vertical hole extending through the flange 2. A vertically 
elongate guide hole 20 establishes communication between the vertical 
holes 19 and the large-diameter portion 7 of the hole 6. 
The stopper 21 comprises a slide shaft slidably inserted in the vertical 
hole 19, and a stopper pin 22 coupled to an intermediate portion of the 
slide shaft so as to be slidable in the guide hole 20. The slide shaft of 
stopper 21 has a length that is substantially equal to the thickness of 
the flange 2. 
The rotary shaft 9 has on its outer periphery a first engaging projection 
23 and a second engaging projection 24 spaced axially a distance 
substantially equal to the distance the stopper pin 21b can slide. 
When in abutment with the top end of the guide hole 20, the stopper pin 22 
is disposed circumferentially opposite the first engaging projection 23. 
Thus, in this state, when the handle 10 is pivoted from the position x 
toward the position z, the first projection 23 abuts the stopper pin 22, 
preventing the handle 10 from further pivoting toward position z. 
On the other hand, when the stopper pin 22 is in abutment with the bottom 
end of the guide hole 20, the stopper pin 21b is disposed 
circumferentially opposite the second engaging projection 24. Thus, in 
this state, as soon as the handle 10 is pivoted from the position x toward 
the position y, the second projection 24 abuts the stopper pin 21b, 
preventing the handle 10 from further pivoting toward position y. 
FIG. 3A shows how upper and lower containers A1, A2 are coupled together by 
the container coupling tool of the embodiment. In the state shown, the top 
protrusion 3a is inserted in a hole b formed in a bottom corner fitting B 
of the upper container A1, while the bottom protrusion 3b is inserted in a 
hole b formed in a top corner fitting B of the lower container A2. 
The handle 10 is temporarily locked in the position x, so that both ends of 
the top and bottom cones 11, 12 protrude from the perimeter of the 
respective protrusions 3a, 3b, thus engaging the containers A1, A2, which 
are thus coupled together. 
To unload the upper container A1 from the lower container A2, the handle 10 
shown in FIG. 3 is pivoted to the position z to unlock the bottom cone 12, 
and then the upper container A1 is lifted. 
By turning the handle 10 to position z, the bottom cone 12 is turned 
together with the rotary shaft 9 to a position where it is entirely inside 
the perimeter of the bottom protrusion 3b, as shown in FIG. 4. 
Thus, by lifting the upper container A1 in this state, the bottom 
protrusion 3b comes out of the hole b of the top corner fitting B of the 
lower container A2, so that the entire coupling tool is raised together 
with the upper container A1. 
As the upper container A1 is lifted, the stopper 21 moves down by gravity 
relative to the tool body 1 until the stopper pin 22 abuts the bottom end 
of the guide hole 20. In this state, the stopper pin 22 is disposed 
circumferentially opposite the second projection 24, so that the handle 10 
can be turned to position x but not from position x toward position y. 
Since the handle 10 cannot be turned to position y while the upper 
container A1 is hung in the air, the top cone 11 is securely held in the 
hole b of the corner fitting B of the upper container A1. The coupling 
tool will thus never drop from the container. 
To remove the container coupling tool from the upper container A1, the 
slide shaft of the stopper 21 is pushed up until the stopper pin 22 is 
axially offset from the second projection 24 as shown in FIG. 6A. Holding 
the stopper 21 in this position, the handle 10 is turned to position y to 
unlock the top cone 11. Then, by pulling down on the coupling tool, the 
top protrusion 3a will come out of the hole b. 
To put the upper container A1 on the lower container A2, the container A1 
is lifted by e.g. a lifting spreader, the top protrusion 3a is inserted 
into a hole b of a bottom corner fitting of the container A1, and the 
handle 10 is turned from position y to position z to unlock the bottom 
cone 12 and engage the top cone 11 with the upper container A1. In this 
state, the container A1 is deposited on the container A2 to let the bottom 
protrusion 3b fit in a hole b of a top corner fitting B of the lower 
containers A2. The handle 10 is then turned to position x to cause the 
bottom cone 12 to engage the lower container A2. 
Since the top cone 11 and the bottom cone 12 are identically shaped, the 
container coupling tool of the embodiment can be used in an upside down 
position. In such a case, when the upper container A1 is lifted with the 
coupling tool coupled to its bottom as shown in FIG. 4, the stopper 21 is 
held in such a position that the stopper pin 22 is disposed 
circumferentially opposite the second projection 24. 
The handle 10 is thus prevented from turning toward the position in which 
the top cone is unlocked and disengaged. It is thus possible to prevent 
the coupling tool from dropping even when it is used in an upside down 
position. 
FIG. 7 shows another coupling tool embodying this invention. In this 
embodiment, a bar or stopper 25 is inserted in an elongate hole 19 formed 
in the tool body 1 perpendicularly to the rotary shaft 9. The stopper 25 
has its outer end pivotally supported by a pin 30 so that when it pivots 
downward by gravity, it partially protrudes downward from the bottom 
opening of the hole 26. In this state, the inner end of the stopper 25 is 
disposed opposite a second engaging projection 24 provided on the rotary 
shaft 9 as shown, or opposite a first engaging projection 23 if the tool 
is used upside down. 
In either case, the stopper 25 prevents the rotary shaft 9 from turning to 
the position where the top cone 11 disengages. Thus, the top cone is kept 
in an engaged position. This prevents the container coupling tool from 
dropping from the upper container when it is hung in the air. 
The container coupling tool can be used in an upside down position. 
As described above, according to this invention, when a container is hung 
in the air with the container coupling tools of the invention coupled to 
the bottom of the container, the stopper of each coupling tool lowers by 
gravity until its inner end opposes the engaging projection in the 
circumferential direction of the rotary shaft. This prevents the handle 
from pivoting toward the position where the top cone disengages. The 
coupling tools thus never drops from a container when the container is in 
the air. 
The stopper means is made up of a small number of parts, i.e. stopper and 
engaging projections, so that it is simple in structure and easy to 
assemble. Further, the container coupling tool can be used either upside 
up or upside down.