HK1099645B - Coupling device and method for connecting and releasing the coupling device - Google Patents

Description

Coupling device and method for connecting and releasing a coupling device

Technical Field

The present invention relates to a coupling device for connection to a corner fitting of a container and a method for connecting and releasing a coupling device for connection to a corner fitting of a container. The coupling device comprises a holder, an engagement part which can be at least partially inserted into and released from the corner fitting. The engagement member has a guide member to guide the engagement member with the corner fitting.

Background

When transporting goods, for example on cargo ships, trains and trucks, unladen, heavy-duty and thermal containers (thermo-containers) are used to a large extent. The containers are easily loaded and unloaded due to their standardized size and robust construction, which allows for stacking of multiple containers one on top of the other. Containers are stacked during both storage and transport of the containers. This design of containers, which are commonly referred to as ISO containers (ISO containers), provides good protection of the transported goods during transport and loading and unloading.

Containers of the type described above are generally rectangular, having a bottom, a top, two side walls and two end walls. One end wall is typically comprised of a door section, which is typically formed as a pair of doors. Corner fittings with oblong holes are typically provided at the corners of the container and can attach and tie the container.

For connecting and fastening two or more containers, devices are used which comprise lockable couplings which can be inserted and locked into the corner fittings of ISO containers. WO2004/020316 discloses a hook coupling for connecting two containers to each other by lowering the upper container and simultaneously rotating it about a central vertical axis to achieve simultaneous movement at all four corners of the container corresponding to the hook coupling geometry. The upper container is released by lifting and simultaneously rotating the upper container about the central vertical axis. In this way all four hooks are released simultaneously and follow a motion opposite to that used to connect the two containers.

Today's transport systems, such as ships, can carry thousands of containers, stacked one on top of the other, to make efficient use of the available space. In order to ensure the security of this loading method during transport, each container is connected to at least one adjacent container, or to the transport vehicle, for example by means of a lockable coupling. The stacked containers are thereby locked to each other and to the transport vehicle, providing a stably connected three-dimensional transport stack.

At present, often thousands of containers are used on the same vessel. This means that a small reduction in the time spent in handling each container makes it possible to save significant time and ultimately to increase the economic efficiency.

What is needed is a quick and efficient loading and unloading of containers, and also a need to minimize personnel requirements during the loading and unloading of containers. Today's container couplers do not require manual manipulation after/during the connection or disconnection of two containers. However, such container couplers present problems in connecting the containers if, for example, the loaded/unloaded vessel is tilted during loading/unloading, since the couplers at all four corners of the container must be engaged simultaneously. The same problem arises if the movement of the crane is not very accurate.

Such as during displacement of containers at sea (caused by waves, wind etc.), the above-mentioned container couplings according to prior art transfer forces between connected containers only on the hole side of the corner fittings.

Thus, there is a need to provide a coupling that is quickly and efficiently handled during loading and unloading.

Disclosure of Invention

It is an object of the present invention to provide a quick and easy to handle coupling device for fastening containers.

The above and other objects, which will be apparent from the following description, are achieved by a coupling device for connection to a corner fitting of a container according to the appended claims.

According to one aspect of the invention, a coupling device for connection to a corner fitting of a container comprises a bracket, an engagement member which is at least partly insertable into and releasable from said corner fitting, said engagement member having a guide member for guiding the engagement member with said corner fitting, wherein said engagement member is rotatably mounted in said bracket by means of a shaft part extending into the bracket, said guide member having a translational guide path for guiding the engagement member in a horizontal direction relative to said corner fitting, which translational guide path is rotationally asymmetric relative to the axis of said shaft part.

The main function of the translational guide path is to provide a horizontal guiding movement for the coupling during its release from the corner fitting. This is achieved by an asymmetric or eccentric translational guide path.

An advantage of the inventive idea is that a fully automatic coupling can be provided which is automatic during the fastening and the detaching of the containers. With the coupling according to the invention, less demands are made on the accuracy and deviation of the movement, and finally the container can have an inclined position during coupling and handling.

A further advantage of the present invention is to provide engagement members to transmit the tie-down load on both sides of the oblong hole of the corner fitting, which does not present a strength problem for couplings according to the prior art.

Preferably, the guide member of the coupling device has a rotation guide path to rotate the engagement member. The rotation guide path drives the engagement member to rotate, which is used to effect automatic release and tie-down of the coupling.

There are different combinations of mechanical elements possible to achieve the translational and rotational guide paths. For example, the cams and screws described in the detailed description below may be utilized in different combinations.

First, a combination of a cam and a surface of a spiral may be used as a translation guide path and a surface of a spiral flange may be used as a rotation guide path. This is the case described in the embodiments of the present invention.

In a second alternative, the cam surface alone may be provided as a translational guide path, while the surface of the helical flange serves as a rotational guide path, in which case the helical flange need not be eccentric or asymmetric, since it does not serve as a translational guide path.

In a third alternative, the surface of the spiral may be arranged as a translation and rotation guide surface, which will result in different geometries of the engagement member and the guide member.

In a preferred embodiment, the rotation guide path has a bevel (pitch) to drive the engagement part in a vertical axial direction parallel to the axis of the shaft relative to the corner fitting during rotation. The inclined portion may be provided as a helical flange or as part of a helical flange, or other geometries may be used to achieve the same effect as with a helical inclined portion.

Furthermore, the rotation guide path has a first guide surface for rotating the engagement part during connection with the corner fitting and a second guide surface for rotating the engagement part during release from the corner fitting. The invention is based on the idea of using a second guide surface in combination with an asymmetrical or eccentric geometry to achieve the property that the coupling is automatic during release.

Furthermore, the guide member preferably has the shape of a spiral or spiral-like geometry, for example, a short spiral flange may be provided, i.e. only on a part of the core circumference. Preferably, the thread of the helix is provided with a lower side and an upper side, constituting the first and second guide surfaces.

In a preferred embodiment, the engagement part is rotatable in one direction against the spring action from the neutral position during connection with the corner fitting and in the opposite direction against the spring action from the neutral position during release from the corner fitting. Thus, the coupling and the engagement member have different characteristics during the clockwise and counterclockwise rotation, respectively, from the neutral position. The spring endeavors to return the engagement member to the neutral position.

Preferably, the engagement member has a cam provided with a translational guide path cooperating with a rotational guide path to interact with the corner fitting during release of the engagement member from the corner fitting to urge the bracket to move with a horizontal component. Advantageously, the cam is fixedly located on the engagement member between the shaft and the guide member.

In a preferred embodiment, the guide member of the coupling device has a conical outer shape. The conical shape facilitates the entry of the engagement member of the coupling into the aperture of the corner fitting during the connection of the container.

Furthermore, it is preferred that the engagement member is provided with two first guide surfaces and two second guide surfaces for guiding with at least two opposite edges of the corner fitting during connection and release, respectively. This helps the coupler to obtain a tie down load on the two contact points of the bore, and furthermore, since the coupler has at least two contact points with the bore of the corner fitting, tilting of the connector is avoided.

In a preferred embodiment, the coupling device is also provided with a second connecting mechanism to connect to an adjacent corner fitting of a second container. This second connection mechanism can be provided according to known or new technology with the purpose of retaining the coupler and bracket in the corner fitting of the first container and also to obtain the load during the lashing and transport of the container. Preferably, the bracket is a close fit in the aperture of the corner fitting.

Advantageously, the engagement member including the guide member, the shaft and the second connection mechanism is formed in one piece. This is advantageous from a manufacturing point of view. Furthermore, a small number of parts and few moving parts will facilitate maintenance.

According to the invention, a method is provided for releasing a first container from a second container connected by a coupling device, which coupling device comprises a bracket, an engagement member which is at least partly insertable into and releasable from said corner fittings of said second container. The method comprises the following steps:

-in an initial step of releasing the containers, lifting the first container in a vertical direction,

-moving the bracket of the coupling device in horizontal and vertical directions from the corner fitting during rotation of the engagement part,

-releasing the coupling device from the corner fitting of the second container by further rotating the engagement part during movement of the bracket of the coupling device in the horizontal and vertical directions, wherein the engagement part will pass the hole of the corner fitting to the release position.

A method for connecting a first container and a second container by means of a coupling device according to the invention, comprising the steps of:

-lowering a first container provided with said coupling towards a second container,

-rotating the engagement member by interaction with a corner fitting of a second container,

-connecting the coupling device to a corner fitting of a second container by moving the first container further in a vertical direction, wherein the engagement member will reach an engagement position through a hole of the corner fitting,

-rotating the engagement member back to the neutral position by means of a spring connected between the bracket and said engagement member.

Preferably, the step of moving the bracket according to the invention during the release of the coupling further comprises said horizontal and vertical movements being actuated by translational and rotational guide paths of the engagement member due to the interaction between the engagement member and the hole of the corner fitting.

Furthermore, the step of moving the carriage further comprises a ramp (pitch) of the rotation guide path driving the engagement member to rotate during operation of the coupling device.

Advantageously, the method further comprises the step of releasing the first container by simultaneously lifting and rotating the container about its central vertical axis. This feature is obtained if the couplers are mounted at all four corners of the container in the same orientation with respect to the corner fittings.

The coupling may be designed such that the forced rotation of the engaging members is effected during release at intervals of 70 deg. -120 deg. (preferably 80 deg. -110 deg., more preferably 90 deg.). During loading, the corresponding design of the angle of rotation of the engaging members is advantageously 90 ° to 120 °, preferably 100 ° to 115 °, more preferably 110 °.

The coupling according to the invention has the advantage that a container can be loaded straight on another container in an automatic connection. Furthermore, little precision is required during loading and one corner of the container can be connected at a time during loading, which is not possible with the prior art couplings.

Drawings

Preferred embodiments will be described in more detail below with reference to the accompanying exemplary drawings, in which:

fig. 1 shows an exploded view of a coupling device according to the invention in a perspective view.

Fig. 2 shows the coupling device in a perspective view with the bracket in section.

Fig. 3 shows the engagement member of the coupling device in a side view.

Fig. 4a, 4b, 4c show the sequence of the upper container with the tilting but secure connection.

Fig. 5a, 5b, 5c, 5d show the sequence in the process of unloading a first upper container from a second container.

Fig. 6a, 6b, 6c, 6d show the sequence of loading the first upper container on top of the second container.

Detailed Description

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings.

An existing corner fitting for connecting an ISO container of a coupling device 1 according to an embodiment of the invention, said coupling device 1 being shown in fig. 1, generally comprises a bracket 2 and an engagement part 3 which is at least partially insertable into and releasable from the corner fitting. The engagement element 3 has a guide element 4 for guiding the engagement element into and out of the oblong hole of the corner fitting.

The coupling device shown in fig. 2 shows a holder 2 and an engaging member 3, the engaging member 3 being rotatably mounted in the holder by a shaft portion 5 extending into the holder 2. The engaging member 3 has a guide member 4 for guiding the engaging member with the corner fitting, the guide member 4 having a shape in which a core 6 is eccentrically arranged with respect to an axis 7 of the shaft 5. Furthermore, two helical flanges project radially from the core 6, which have a first upper guide surface 8, 8 'and a second lower guide surface 9, 9'. The flange is inclined in the circumferential direction and narrows downward in the radial direction. The angle of the obliquely rotating guide surface needs to be large enough to avoid self-locking with the edge of the hole during rotation of the engaging part 3.

A cam 10 is formed directly above the guide member 4, the eccentric portion of the cam 10 having substantially the same extension direction as the eccentricity of the guide member 4 with respect to the axis 7 of the shaft 5. For manufacturing reasons, the engaging member 3 is made of one piece of material.

In the present embodiment, the combination of the surface of the cam 10 and the surface of the spiral 10' serves as a translational guide path for guiding the engaging member 3 in the horizontal direction with respect to the corner fitting.

In this embodiment of the invention, the bracket 2 comprises two halves. The two halves are assembled around the shaft 5 of the joint part 3. The support frame 2 is designed such that the engagement member 3 can be rotated about the axis 7 of the shaft 5, and furthermore a second coupling means 11 extends from the support frame 2 for coupling with the corner fitting of the first upper container. The second connecting mechanism 11 can be retracted into the stand 2 by rotating the engaging member 3 so that the coupling 1 and the first container can be connected.

A chamber 13 is provided in the lower part of the bracket 2 to allow the coupler and bracket to move up and sideways during unloading, the chamber 13 will prevent the bracket 2 from colliding with the edge of the hole in the corner fitting. Furthermore, the bracket is provided with recesses or projections 14, said recesses or projections 14 extending horizontally around the bracket to position the bracket 2 relative to the apertures of the corner fittings of the container.

The helical flange of the guide member 4 may be described as a double acting twist cone (double acting twist cone) which is asymmetrically oriented with respect to the rotational axis 7 of the engagement member 3. The double acting torsion cone drives the engagement members into rotation during engagement and release of the coupling 1 and the corner fitting, wherein vertical movement of the coupling 1 is partly converted into forced rotation of the engagement members 3. During unloading of the container the eccentric position of the double acting torsion cone cooperates with the cam 10 to urge the container in a lateral direction. On the other hand, during loading, the cam 10 and the eccentric torsion cone act in different ways, due to the rotation in opposite directions.

The coupling 1 according to the invention is described for connecting two containers to each other, but the invention can also be used in other applications. For example, for attaching containers to a vehicle, ship floor, or other connection or application requiring automatic coupling.

Fig. 4a shows a first upper container securely stacked and coupled to a second lower container by means of four coupling devices 1.

Fig. 4b shows an initial stage of tilting the container, for example caused by a large inclination of the loaded vessel.

Fig. 4c shows the sequence during tilting when the couplings on the long side of the container are pulled apart and their engaging parts start to rotate. But the couplings on the opposite side are compressed and prevent the first upper container from moving in the horizontal direction, wherein the containers remain securely connected.

If the vessel sways due to sea storms, it is necessary that the containers remain attached when the stack of containers is tilted, as shown in fig. 4 a-c. In this case each container is tilted, usually sideways with respect to the length direction of the container and the ship, and thus the two couplings on the long side are compressed, while the opposite couplings are pulled apart, as shown in fig. 4 c. During unloading, the two couplers that are pulled apart initially move in the same way, but because the two compressed couplers prevent the container from moving in the horizontal direction, the engaging members 3 of the pulled apart couplers cannot perform a horizontal movement driven by the shape of the guiding members 4 as the brackets fit in the corner fittings of the first and second containers, so that the container will remain securely connected.

For the coupler pulled apart, the rotational path of the guide member 4 starts to rotate the engagement member counterclockwise (as viewed from below), and the translational guide path of the cam 10 is in contact with the long side edge of the hole. Further, the inclination of the rotation guide path is intended to drive the engaging member 3 and the carriage 2 upward while the eccentricity of the cam 10 and the guide member is intended to drive the carriage 2 in the horizontal direction. But the horizontal movement is prevented by the pair of couplings being compressed, so that the two couplings that are pulled apart cannot continue to be released from the holes of the corner fittings.

Fig. 5a shows an initial step in the process of unloading a first upper container coupled to a second container.

Fig. 5b shows the starting step, in which the first lifted container is geometrically guided by the shape and characteristics of the engaging parts 3 of the coupling 1 by driving the lifted container into rotation during lifting (geometric guided).

A further step in the process of releasing the lifted container is shown in fig. 5 c. The engagement member 3 has been rotated (approximately 90 deg.) to a position where it can pass through the aperture of the corner fitting.

Fig. 5d shows the first container in a released state, in which the engaging member 3 has been rotated back to the neutral position by the spring 12.

As shown in fig. 5a-d, during unloading of a first container connected to a second container, a lifting device is used to lift the first container from the second container. During lifting of the first container and the four coupling devices 1, the inclination of the second guide surface 9 of the guide member 4 will cause the engaging member 3 to rotate in a counter-clockwise direction (as seen from below). When the engaging member 3 is rotated, the translational path of the cam will interact with the long side of the hole and push the bracket 2 sideways, as shown in fig. 5 b-c. The core of the guide member 4 lies on a line of approximately 45 ° with respect to a line passing through the axis 7, which line is parallel to the oblong direction of the hole and the core is also eccentrically located at a distance of 18mm with respect to the axis of rotation 7 of the shaft 5. Due to the fact that the core of the guide member 4 is arranged eccentrically by 45 deg. as described above, the bracket 2 and the first container will be driven to move during unloading, with a horizontal component in a direction parallel to the short sides of the container, as shown in fig. 3.

Since the coupling device 1 is coupled into the corner fittings of the first container by means of the second connection means 11, the first coupling device 1 will follow the lifted container. All four couplings will move up and sideways simultaneously and they will wait for each other if required.

During the initial rotation of the engaging member 3, the engaging member will force the bracket 2 and the first container to move upwards and in a horizontal direction, as shown in fig. 5b, due to the eccentric position of the guide member 4 and the translational path of the cam 10. The cam 10 and the eccentric position will interact with the edge of the oblong hole of the corner fitting and the engaging member 3 will rotate substantially 90 deg. and guide the guiding member 4 to the position of the coupling 1 released from the second container. During unloading of the first container all four engagement members of the coupling will rotate and release more or less simultaneously. Since the release is fully automatic, no manual operation of the coupling 1 is required before lifting off the first container.

During the release of the coupling 1, the inclined portion of the guide surface 9 of the guide member 4 converts the vertical lifting movement of the engagement member 3 into a driving rotation, and this driving rotation is used by the geometry of the guide member 4 (i.e. the eccentrically positioned helical flange and the asymmetric cam geometry) to drive the bracket 2 in a direction having a horizontal component.

When the first container is released and the engagement member 3 of the coupling 1 is disengaged from the hole of the corner fitting, a spring 12 connected between the bracket 2 and the engagement member 3 rotates the engagement member back to the neutral position, as shown in fig. 5 d.

The neutral rotational position is obtained by the springs 12 acting on both sides of the recess in the shaft 5 and the recess in the holder 2, which returns the engaging member 3 from the rotated position, which is reached by rotating clockwise and counterclockwise from the neutral position, to the neutral position.

The four couplers of the container may be mounted with the same orientation in or relative to the four corner fittings. The first orientation moves a first container laterally relative to a length of the container, wherein the first container is unloaded by the lifting movement from the lifting device. While the container is lifted, the latter orientation causes the unloading movement to become a rotation of the container about the vertical central axis, as shown in fig. 5 b-c.

Fig. 6a shows the first container above the second container in a position of engagement with each other.

In fig. 6b, the first container is lowered straight towards the second container, and the engagement member 3 of the coupling will rotate due to the contact between the guiding surfaces 8, 8' and the edge of the hole in the corner fitting.

Fig. 6c shows how the engaging part 3 is passed down into the oblong hole of the corner fitting. The engaging member 3 moves while rotating, and the circular arc is substantially in the longitudinal direction of the elliptical hole. When the coupling is engaged with a second container, the spring 12 urges the engagement member 3 to rotate back (anticlockwise from below) to a neutral position, as shown in figure 6 d.

During loading (typically stacking one container on top of another container) the coupling device according to the invention is mounted in the holes of the four corner fittings of the lower part of the container to be loaded by using the second attachment means 11, as shown in fig. 6 a-d. A crane or other lifting device lifts the first container above the second container and lowers the first container straight onto the second container. During lowering of the first container the engaging member 3 of the coupling device 1 will rotate clockwise (as seen from below) due to the contact between the edge of the hole and the rotation guiding path of the engaging member 3. The guide member 4 will rotate from a neutral position and the resultant movement will be generally in the longitudinal direction of the oblong hole of the corner fitting. This is due to the fact that the core 6 of the guide member 4 is eccentrically arranged at a distance of 18mm from the axis of rotation 7 of the shaft 5, as shown in figure 3, and that the core lies substantially on a line of 45 ° with respect to a line passing through the axis 7, which line is parallel to the oblong direction of the hole. During engagement between the engagement member 3 and the hole of the upper corner fitting of the second container, the first container can be lowered straight vertically onto the second container, since the guide member 4 is moved generally in the oblong direction of the hole.

In the initial stage of engagement of the engagement members 3 with the corner fittings, the first container is guided to a position above the second container by guiding the tapered portions of the guide members 4 into the holes of the corner fittings of the second container, as shown in fig. 6 b. In the next step of the coupling sequence, the parallel edges of the holes of the corner fittings will act as guides for the first guide surfaces 8 of the rotational guide path, as shown in fig. 6 c. When the first container is lowered from this position, the engaging member 3 starts to rotate due to the inclined portion of the first guiding surface and will be guided in the hole. The helical first guide surface forces the engaging member 3 to rotate substantially 110 deg. from the neutral position. During this rotation, the cam 10 is inactive, since the radially extending asymmetric portion of the cam 10 is oriented in the long circular direction of the hole when the engaging member 3 is engaged in rotation.

During the final stage of coupling of the two containers, when the guide element 4 of the engaging element 3 has fully entered the corner fitting, the spring 12 provided between the bracket 2 and the engaging element 3 will rotate the engaging element back to a (substantially 110 °) neutral position, thereby locking the first and second containers together, as shown in fig. 6d, because the guide element 4 is eccentrically positioned, as shown in fig. 3, but also because the guide element 4 has an oblong shape in horizontal cross-section, which cannot pass directly through the oblong hole of the corner fitting.

So that with the coupling 1 according to the invention it is possible to load and connect two containers to each other fully automatically and without manual operation of the coupling other than the connection of the coupling to the first container.

One of the four coupling devices can be engaged separately during the connection of the two containers, i.e. without having to engage the coupling devices simultaneously in the four corner fittings of the second container. This may be the case, for example, if the vessel is tilted during loading (e.g. caused by asymmetric loading of the vessel), the crane operator does not need to lower all four corners of the first container at the same time to make the connection. The coupling will automatically provide engagement of the two containers without any manual operation.

Claims (18)

1. Coupling device (1) to a corner fitting of a container, said coupling device comprising a bracket (2), an engagement part (3) which is at least partly insertable into and releasable from said corner fitting, said engagement part (3) having a guide part (4) for guiding the engagement part with said corner fitting, characterized in that said engagement part (3) is rotatably mounted in said bracket (2) by means of a shaft part (5) extending into the bracket, said guide part (4) having a translational guide path for guiding the engagement part (3) in a horizontal direction relative to said corner fitting, said translational guide path being rotationally asymmetric relative to an axis (7) of said shaft part (5).

2. The coupling device (1) as claimed in claim 1, wherein the guide member (4) has a rotation guide path to rotate the engaging member (3).

3. Coupling device (1) according to claim 2, wherein the rotation guide path has an inclined portion to drive the engaging part (3) in a vertical axis direction parallel to the axis (7) of the shaft (5) relative to the corner fitting during rotation.

4. Coupling device (1) according to claim 2 or 3, wherein the rotation guide path has a first guide surface (8) for rotating the engagement part (3) during connection with the corner fitting and a second guide surface (9) for rotating the engagement part (3) during release from the corner fitting.

5. Coupling device (1) according to any one of claims 1-3, wherein the guide member (4) has a helical shape.

6. Coupling device (1) according to claim 5, wherein the helical thread is provided with an upper and a lower side, constituting the first (8) and second (9) guide surfaces.

7. Coupling device (1) according to any one of claims 1-3, wherein the engagement part (3) is rotatable in one direction against the spring action from a neutral position during connection with the corner fitting and in the opposite direction against the spring action from a neutral position during release from the corner fitting.

8. Coupling device (1) according to any one of claims 1-3, wherein the engagement part (3) has a cam (10) provided with a translational guide path which, in cooperation with a rotational guide, interacts with the corner fitting during release of the engagement part (3) from the corner fitting, drives the bracket (2) in a horizontal component.

9. Coupling device (1) according to claim 8, wherein the cam (10) is fixedly positioned on the engagement part (3) between the shaft (5) and the guide part (4).

10. Coupling device (1) according to any one of claims 1-3, wherein the guide member (4) has a conical shape.

11. Coupling device (1) according to any one of claims 1-3, wherein the engagement part (3) is provided with two first guide surfaces (8, 8 ') and two second guide surfaces (9, 9') for guiding with at least two opposite edges of the corner fitting during connection and release, respectively.

12. A coupling device (1) according to any one of claims 1-3, wherein the coupling device is further provided with second connection means (11) for connection to adjacent corner fittings of a second container.

13. The coupling device (1) according to claim 12, wherein the engagement member (3) comprising the guide member (4), the shaft (5) and the second connection means (11) is formed in one piece.

14. Coupling device (1) according to any one of claims 1-3, wherein the bracket fits tightly in the hole of the corner fitting.

15. Method for releasing a first container from a second container connected by a coupling device (1) comprising a bracket (2), an engagement member (3) which is at least partly insertable into and releasable from said corner fittings of said second container, characterized in that it comprises the steps of:

in an initial step of releasing the containers, the first container is lifted in a vertical direction,

during the rotation of the engagement part (3), the bracket of the coupling device is moved in the horizontal and vertical directions from the corner fitting,

during the movement of the bracket of the coupling device in the horizontal and vertical directions, said coupling device is released from the corner fitting of the second container by further rotating the engagement member,

wherein the engagement part (3) is to be brought into the release position through the hole of the corner fitting.

16. The method according to claim 15, wherein said horizontal and vertical movements of the step of moving the bracket are further driven by translational and rotational guiding paths of said engaging member (3) due to the interaction between the engaging member and the hole of the corner fitting.

17. The method of claim 16, wherein the step of moving the carriage further comprises the step of the ramp of the rotational guide path driving the engagement member (3) to rotate during operation of the connection device.

18. A method according to any one of claims 15-17, further comprising the step of releasing the first container by simultaneously lifting and rotating the container about its central vertical axis.