EP4458729A1

EP4458729A1 - Locking arrangement for joining containers together and method for joining together an upper container and a lower container

Info

Publication number: EP4458729A1
Application number: EP23171771.1A
Authority: EP
Inventors: Juhana ÖSTBERG
Original assignee: MacGregor Fin Oy
Current assignee: MacGregor Fin Oy
Priority date: 2023-05-05
Filing date: 2023-05-05
Publication date: 2024-11-06
Also published as: JP2024160984A; CN118894310A; TW202508929A; KR20240161778A

Abstract

A locking arrangement for joining together an upper container (5) and a lower container (6). The locking arrangement comprises a lower corner piece (7) of the upper container (5) comprising a bottom flange (9) and an upper opening (8) comprising a left upper opening wall (15a) and a right upper opening wall (15b); an upper corner piece (10) of the lower container (6) comprising a top flange (12) and a lower opening (11) comprising a lower opening wall (24); and a container lock (1) for locking to each other the lower corner piece (7) and the upper corner piece (10). The container lock (1) comprises a front wall (25), a back wall (26), a central flange (3), and a stopper (27), wherein the stopper (27) is configured to limit horizontal direction movement, wherein a horizontal direction (X) is from the front wall (25) to the back wall (26); prevent the back wall (26) to contact with the left upper opening wall (15a) ; and form a back wall clearance (X1) between the back wall (26) and the left upper opening wall (15a). Also a method is disclosed.

Description

FIELD OF THE INVENTION

The present application relates generally to a locking arrangement. More specifically, the present application relates to joining together an upper and a lower container stacked on top of each other with a container lock.

BACKGROUND OF THE INVENTION

At sea, large compression and tension forces are exerted on container locks and on corner pieces of a container when a ship, and correspondingly a stack of containers on its deck, inclines. Known container locks have relatively much free space between contact surfaces of the container lock and corresponding container corners. This may cause a big vertical gap between the container corners when the ship is heeling, and the container stacks are tilting from side-to-side at rough sea. Geometry of a container lock in relation to container corner pieces to which the container lock is attached to may be optimized to improve security of container locking.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The scope of protection sought for various embodiments of the present disclosure is set out by the independent claims.
Example embodiments of the present disclosure provide a locking arrangement for joining together an upper and a lower container stacked on top of each other with a container lock having an optimized geometry in relation to container corner pieces to which the container lock is attached to. When using this type of container locks more cargo may be carried on a similar ship as heavier containers are allowed in container stacks on a deck of the ship. This may have a positive impact on the productivity of the ship. Also greenhouse gas emissions per carried cargo ton may be reduced when a full capacity of the container ship is utilized. From manufacturing point of view the optimized geometry may not bring any new challenges and conventional manufacturing methods may be applicable. As a result the manufacturing costs may not be higher than with traditional container locks.
According to a first aspect, a locking arrangement for joining together an upper container and a lower container stacked on top of each other is disclosed. The locking arrangement may comprise a lower corner piece of the upper container, which may comprise a bottom flange and an upper opening, which upper opening may comprise a left upper opening wall and a right upper opening wall; an upper corner piece of the lower container, which may comprise a top flange and a lower opening, which may comprise a lower opening wall; and a container lock for locking to each other the lower corner piece and the upper corner piece, wherein the container lock may comprise a front wall, a back wall, a central flange, and a stopper, wherein the stopper may be configured to limit horizontal direction movement, wherein a horizontal direction may be from the front wall to the back wall; prevent the back wall to contact with the left upper opening wall; and form a back wall clearance between a back wall and the left upper opening wall. The container lock with optimized geometry may improve security of the container locking, for example, container-to-container locking in each stack of containers on a deck of the ship by minimizing an opening slack or clearance under a full tension load.
According to an example embodiment of the first aspect, the locking arrangement may have a front wall clearance between the front wall and the right upper opening wall; in a tension position, the back wall clearance is greater than the front wall clearance; and in the tension position, the container lock located between the upper container and the lower container may be configured to be under an upward tension stress, when the container lock is located on the right side of a container stack and the container stack is heeling to the left. Because of the stopper there may always be the back wall clearance, which may reduce the front wall clearance and a vertical slack between the containers. This may decrease dynamic tension forces acting between the containers and the container locks when the ship is heeling from side to side.
According to an example embodiment of the first aspect, the back wall clearance may be greater than the front wall clearance, when a central flange top surface may be configured to be in contact with a bottom flange bottom surface; and the container lock may be configured to be pushed in the horizontal direction. This may be the tension position. It may make possible to increase weight of the containers and thus improving cargo carrying capacity and efficiency of the ship.
According to an example embodiment of the first aspect, in the tension position, the lock arrangement may be configured to fulfil a formula wherein a tension clearance TC = Y1 - Y0, wherein Y1 may be a vertical distance between a bottom flange bottom surface and a top flange top surface; Y0 may be a thickness of a central flange; wherein the tension clearance may be a total vertical clearance generated by the upward tension stress from the upper container; and wherein the tension clearance may be from 0 to 15 mm. In the tension position, the vertical slack between the containers may be reduced and it may be smaller than when using known container locks.
According to an example embodiment of the first aspect, the tension clearance may be from 4 to 14 mm.
According to an example embodiment of the first aspect, the tension clearance may be from 4 to 10 mm.
According to an example embodiment of the first aspect, the container lock may be a fully automatic lock. The fully automatic lock may enable easy locking of the containers together.
According to an example embodiment of the first aspect, a body of the container lock may be made of one piece.
According to an example embodiment of the first aspect, the back wall may comprise the stopper, and/or the stopper may be located on the central flange. The stopper may be located at different places to limit the horizontal direction movement of the container lock, which may reduce the front wall clearance and the tension clearance. This may reduce the vertical slack between the containers and dynamic tension forces.
According to an example embodiment of the first aspect, the stopper may be located above the central flange and/or on the back wall.
According to an example embodiment, the stopper is configured to be in contact with the flange chamfer of the lower corner piece of the upper container and/or is configured to be in contact with the left upper opening wall of the lower corner piece.
According to an example embodiment of the first aspect, the stopper may be located on the back wall and may be configured to be in contact with the left upper opening wall (15a); and a height, a depth, and/or a width of the stopper may be at least 2 mm. According to an example embodiment of the first aspect, the stopper is located on the back wall above a central flange upper surface and configured to have no contact with the flange chamfer of the bottom flange. Therefore, the size of the stopper may be small.
According to an example embodiment of the first aspect, the stopper has a triangular or rectangular form. The stopper may have different forms, which may be suitable for limiting horizontal movement of the container lock.
According to an example embodiment of the first aspect, the bottom flange may comprise a flange chamfer, which may comprise a bottom chamfer height, and a bottom chamfer width; the triangular stopper may comprise a lock chamfer, a lock chamfer height, and a lock chamfer width; and the lock chamfer height and/or the lock chamfer width is greater than the bottom chamfer height and/or a bottom chamfer width. The width and/or the length of the lock chamfer may be greater than the width and/or the length of the bottom chamfer to form back wall clearance.
According to an example embodiment of the first aspect, the lock chamfer height may be at least 7 mm; and/or the lock chamfer width may be at least 7 mm.
According to an example embodiment of the first aspect, the rectangular stopper may comprise a rectangular height, and a rectangular width; and the rectangular height may be at least 3 mm and/or the rectangular width may be at least 3 mm. These measurements may allow the rectangular stopper to form back wall clearance.
According to a second aspect, a method for joining together an upper container and a lower container stacked on top of each other with a locking arrangement is disclosed. The locking arrangement may comprise a lower corner piece of the upper container, which may comprise a bottom flange and an upper opening, which may comprise a left upper opening wall and a right upper opening wall; an upper corner piece of the lower container, which may comprise a top flange and a lower opening, which may comprise a lower opening wall; and a container lock for locking to each other the lower corner piece and the upper corner piece, wherein the container lock may comprise a front wall, a back wall, a central flange, and a stopper, wherein the method may comprise limiting, by the stopper, horizontal direction movement, wherein a horizontal direction may be from the front wall to the back wall; preventing, by the stopper, the back wall to contact with the left upper opening wall; and forming, by the stopper, a back wall clearance between the back wall and the left upper opening wall. The container lock with optimized geometry may improve security of the container locking, for example, container-to-container locking in each stack of containers on a deck of the ship by minimizing an opening slack or clearance under a full tension load.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:

Fig. 1 shows schematically an example of stacked containers on a deck of a ship supported with lashing bars according to an example embodiment?;
Fig. 2a shows schematically an example of a cross-sectional side view of a locking arrangement on the left side of a container stack when the container stack is heeling to left and the left side container corners are compressed downwards according to an example embodiment;
Fig. 2b shows schematically an example of a cross-sectional side view of a locking arrangement on the right side of the container stack when the container stack is heeling to left and the right side container corners are in a tension position according to an example embodiment;
Fig. 3 shows schematically an example of a cross-sectional side view of a stopper of Fig. 2b in the tension position according to an example embodiment; and
Fig.4 shows an example method for joining together containers with the locking arrangement according to an example embodiment.

Like references are used to designate like parts in the accompanying drawings.

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments, examples of which are illustrated in the accompanying drawings. The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utilized. The description sets forth the functions of the example and the sequence of steps or operations for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples.
On a cargo ship, containers may be transported on a deck on top of hatch covers in a number of parallel rows and lines and also in a number of tiers one on top of the other. The containers may have corner pieces on all their eight corners, by means of which corner pieces the containers may be locked to each other. Typically, two containers one above the other may be locked to each other with container locks installed into the corner pieces of the containers. When the container lock is used it may first be manually installed into a bottom corner of a container. Totally four pieces container locks may be installed into the bottom of the one container, one in each corner. In more detail, upper cones of the container locks may now be inside the bottom corners of the container. Then the container may be lifted by a crane onto another container on a deck of the ship. Lower cones of the container locks that are hanging in the lifted bottom corners of the container may be guided and locked into the top corners of a lower container already on board the ship. Same procedure may be repeated to all the containers that are lifted on the deck.
At the sea, the container locks may connect together the containers of one vertical stack. When the ship is heeling at rough weather each stack of containers may be tilted sideways. In this situation the container locks me be subjected to heavy tension load. The upper container may pull the container lock upwards while the lower container may cause an opposite force downwards. As there is usually some clearance between the container locks and the container corner pieces, additional dynamic forces may be generated. When the ship is heeling the forces may cause a big vertical gap between the container corners and the container stacks may tilt from side to side at rough sea. As this kind of large vertical gap may exist between all the containers in the stack the total effect may be remarkable. For example, ten containers may be located on top of each other in one stack. As a result there may be big tension forces in the container locks and lashing bars that may give additional support to the stacked containers. Therefore any extra slack or clearance between mentioned components should be eliminated.
According to the example embodiment, the containers may be locked to each other in such a way that the seaway-induced tension force is smaller than before, in which case the number and/or weight of the containers being transported on the cargo ship may be increased. The locking arrangement may present an optimized geometry of the container lock in relation to the container corner pieces to which the container lock may be attached to. The optimized geometry means that the container lock may have no or very little clearance between the contact surfaces of the corner pieces and the container lock. The container lock with optimized geometry may improve the security of the container locking i.e. container-to-container locking in each stack of containers on the deck of the ship by minimizing the opening slack or clearance under full tension load.
According to an example embodiment, the container lock may be so called fully automatic lock which does not require any manual locking and unlocking operations when the containers are lifted onto the cargo ship or lifted away from the ship. The automatic function may be based on diagonal movement of the container sideways that may be caused by wedge-type guiding surfaces of a container lock bottom part when the container is landing onto a container below or when the container is lifted up from top of another container.
According to an example embodiment, with a known fully automatic lock there is relatively much clearance between contact surfaces of the lock and container corners. When the ship is sailing at rough sea and heeling from side to side the container stacks may tilt heavily from side to side, which may cause high tension forces between the container and the container locks. Any extra slack in the system such as large gaps between the containers in the tilted stack may increase stress and forces of the container locks, lashing bars and the containers. There may be breakage of any of above mentioned components leading to cargo damages or even losing containers overboard. Because of the container slack maximum allowed container stack weights must be limited and the ship may not take as much cargo as it could with the corresponding small-clearance container locks.
According to an example embodiment, a one-piece type container lock is disclosed. An upper and a lower part of the container lock may form a uniform solid body, which may have an upper cone geometry that may keep the container lock in a position where a back wall clearance of the container lock may be bigger than a front wall clearance of the container lock under the following conditions: a central flange top surface of the container lock may be in contact with a bottom flange bottom surface of a lower corner piece of the upper container and the container lock may be pushed sideways to a horizontal direction that may be opposite to a nose of a container lock lower cone. A sideways pushing force may be caused by a vertical tension load and a sloped upper surface of the nose may be in contact with a top flange of an upper corner piece of the lower container. This may correspond a situation where the container lock may be under vertical tension load between the containers. The back wall clearance may be a clearance between a back wall of the container lock and an upper vertical opening wall of an upper opening of the bottom flange. The front wall clearance is a clearance between a front wall of the container lock and the upper vertical opening wall of the upper opening of the bottom flange. A corner area of the central flange top surface and the back wall of the container lock may comprise a chamfer or a stopper surface. The chamfer may comprise a lock chamfer height and a lock chamfer width, wherein the lock chamfer height and/or the lock chamfer width may be greater than a bottom chamfer height and/or a bottom chamfer width of a corresponding chamfer at a lower edge of the upper opening of the bottom flange. In the corner area of the central flange top surface and the back wall of the container lock may be a chamfer with the lock chamfer height ≥ 7 mm and/or the lock chamfer width ≥7 mm.
An example of Fig. 1 shows schematically stacked containers on a deck 34 of a ship supported with lashing bars 30. A lashing bridge 33 may be fixed to the deck 34 of the ship. Container stacks 31 may comprise containers 5, 6 on top of each other. The container stacks 31 may stand on hatch covers 32 resting on the deck 34. The lashing bars 30 may be attached to the containers 5, 6.
Examples of Fig. 2a and Fig. 2b present container locks 1 between containers onboard the ship. It may be possible to modify the container lock 1 geometry compared to what is presented in Fig. 2a, 2b, and 3. For example, a form, angles and dimensions of a stopper 27 may be changed. Also a form and angles of a nose 13 may be changed. The containers 5, 6 may have at least one locking arrangement. However, the containers 5, 6 may have locking arrangements on all their eight corners, by means of which locking arrangements the containers 5, 6 may be locked to each other.
An example of Fig. 2a shows a cross-sectional side view of a locking arrangement on the left side of a container stack 31 when the container stack is heeling to left and the left side of upper container corners are compressed downwards. An example of Fig. 2b shows schematically an example of a cross-sectional side view of a locking arrangement on the right side of the container stack 31 when the container stack is heeling to left and the right side of upper container corners are in a tension position and are pulled upwards with a tension stress T.
Examples of Fig. 2a and 2b show schematically cross-sectional side views of the locking arrangements, wherein the left side of the upper container 5 is compressed downwards and the right side is in the tension position. They may comprise upper and lower corner pieces 7, 10 of the two containers 5, 6 that may be one above the other. The lower corner piece 7 may belong to the upper container 5 and the upper corner piece 10 to the lower container 6. The actual containers 5, 6 are not presented in these drawings as a whole, but the containers 5, 6 may have a corner piece 7, 10 on each corner, by means of which corner pieces 7, 10 the containers 5, 6 may be locked together by using the container lock 1. The container lock 1 thus may lock together the container corner pieces 7, 10 that are one above another.
A container lock 1 may comprise following functional parts: an upper cone 2, a central flange 3, and a lower cone 4. The lower cone 4 may be divided to a linear front part 35, located below the central flange 3, and a triangular locking nose 13 further below the linear front part 35.
The container lock upper cone 2 may be installed into the lower corner piece 7 of the upper container 5 through an upper opening 8 at the bottom flange 9. The container lock lower cone 4 may be inside the upper corner piece 10 of the lower container 6. There may be a lower opening 11 at a top flange 12 of the upper corner piece 10. The nose 13 may comprise an upper surface 14, which may be sloped. The upper surface 14 may have a lower cone contact point 17. The contact point 17 may be a point wherein a lower container corner piece contact point 16 touches the container lock 1 and may lock the container lock 1 to the top flange 12 in a tension position. The lower container corner piece contact point 16 may be the lower edge of the top flange 12. The lower container corner piece contact point 16 may contact the contact point 17 at the upper part of the upper surface 14 of the nose close to the linear front part 35.
The examples of Fig. 2a and 2b show container locks 1 and the container corner pieces 7, 10 in a situation when the ship is heeling and the container stack 31 is tilted sideways to the left. On the left side of the container stack 31, in Fig. 2a, the container corners may be compressed downwards while on the opposite side of the stack 31, in Fig. 2b, the container lock 1 and the lower container upper corner piece 12 may be pulled upwards by the upper container 5. In other words the container locks 1 may keep the container stacks 5 together. In tension position, in Fig. 2b on the right, the upper container lower corner piece 7 may have been moved upwards and also sideways due to vertical and horizontal clearances between the container corner pieces 7, 10 and the container lock 1. The container lock 1 may be pushed to left due to upward tension stress T and the sloped upper contact surface 14 acting against the edge of the lower opening 11 and the lower container corner piece contact point 16. Because of a geometry of the container lock 1 comprising a stopper 27, horizontal movement to the left, i.e. to the opposite direction than the nose 13, in relation to the upper container bottom corner may be restricted more than with traditional container locks, which in turn may make a vertical gap or a tension clearance TC between the containers 5, 6 smaller. This situation may form a back wall clearance X1 between the back wall 26 and a vertical left upper opening wall 15a of the upper opening 8. The locking arrangement may also have a front wall clearance X2 between the front wall 25 and the right upper opening wall 15b. In the described situation the clearance X1 may be bigger than X2.
According to an example embodiment, a traditional locking arrangement has a container lock, which does not comprise a stopper. In a tension position a back wall clearance may be zero as the traditional container lock may be pushed to left due to tension stress T and a sloped upper contact surface acting against the edge of an upper opening. This may also cause a back wall to contact the left upper opening wall and a front wall clearance to be bigger than the back wall clearance.
According to an example embodiment, the locking arrangement may also have a vertical distance Y1 between a bottom flange bottom surface 21 of the upper container 5 and a top flange top surface 23 of the lower container. The locking arrangement comprising a stopper 27 may have smaller vertical distance Y1 as a traditional locking arrangement, which may not have a container lock comprising a stopper.
According to an example embodiment, the locking arrangement may also have a linear front part clearance X3 between the linear front part 35 and the lower opening wall 24 of the lower opening 11. The locking arrangement comprising a stopper 27 may have smaller linear front part clearance X3 than a traditional locking arrangement, which may not have a container lock comprising a stopper because a back wall clearance is zero.
With the container lock 1 comprising the stopper 27 the vertical tension clearance TC between the containers 5, 6 may be made smaller which may decrease the dynamic tension forces acting between the containers 5, 6 and the container locks 1 when the ship is heeling from side to side. This way it may be possible to increase weight of the containers 5, 6 and thus improve cargo carrying capacity and efficiency of the ship.
According to an example embodiment, a locking arrangement comprises a lower corner piece 7 of an upper container 5 comprising a bottom flange 9 and an upper opening 8 comprising a left upper opening wall 15a and a right upper opening wall 15b. The locking arrangement may comprise an upper corner piece 10 of the lower container 6 comprising a top flange 12 and a lower opening 11 comprising a lower opening wall 24. The upper opening walls 15a, 15b and the lower opening wall 24 may be vertical. The locking arrangement may further comprise a container lock 1 for locking to each other the lower corner piece 7 and the upper corner piece 10. The container lock 1 may comprise a front wall 25, a back wall 26, a central flange 3, and a stopper 27. The back wall 26 is located on a back side of the container lock 1 and the front wall 25 is located on a front part of the container lock 1. The stopper may be configured to limit horizontal direction movement, wherein a horizontal direction X may be from the front wall 25 to the back wall 26. The stopper may further be configured to prevent the back wall 26 to contact with the left upper opening wall 15a and to form a back wall clearance X1 between the back wall 26 and the left upper opening wall 15a.
According to an example embodiment, the locking arrangement has a front wall clearance X2 between the front wall 25 and the right upper opening wall 15b, and in a tension position, the back wall clearance X1 is greater than the front wall clearance X2, X1 > X2. In the tension position, the container lock 1 located between the upper container 5 and the lower container 6 may be configured to be under an upward tension stress T, when the container lock 1 is located on the right side of a container stack 31 and the container stack 31 is heeling to the left.
According to an example embodiment, in the tension position the upward tension stress T is generated from the upper container 5. In the tension position, the container locks 1 located on the right side of the container stack 31 may heel to the left.
According to an example embodiment, the back wall clearance X1 is greater than the front wall clearance X2, when a central flange top surface 20 is configured to be in contact with a bottom flange bottom surface 21 and when the container lock 1 is configured to be pushed in the horizontal direction X.
According to an example embodiment, in the tension position the lock arrangement is configured to fulfil a formula wherein a tension clearance TC = Y1 - Y0, wherein Y1 is a vertical distance between a bottom flange bottom surface 21 and a top flange top surface 23 and Y0 is a thickness of a central flange 3, wherein the tension clearance TC is a total vertical clearance generated by the upward tension stress T from the upper container 5, and wherein the tension clearance TC is from 0 to 15 mm. Vertical direction Y is perpendicular to horizontal direction.
According to an example embodiment, the tension clearance TC is from 4 to 14 mm, or from 4 to 10 mm.
According to an example embodiment, the tension clearance TC is a total vertical clearance generated by the upward tension stress T from the upper container 5. The container lock 1 may be pushed to left due to the upward tension stress T and the sloped upper contact surface 14 acting against the edge of the lower opening 11, which may be the lower container corner piece contact point 16.
According to an example embodiment, the container lock 1 is a fully automatic lock.
According to an example embodiment, a body of the container lock 1 is made of one piece.
According to an example embodiment, the back wall 26 may comprises the stopper 27, and/or the stopper 27 is located on the central flange 3.
According to an example embodiment, the stopper 27 is located above the central flange 3 and/or on the back wall 26. The stopper 27 may have a triangular, rectangular, or any other form seen from a left or right side of the container lock 1.
According to an example embodiment, the stopper 27 is configured to be in contact with the flange chamfer 28 of the lower corner piece 7 of the upper container 5.
According to an example embodiment, the stopper 27 is located on the back wall 26 and is configured to be in contact with the left upper opening wall 15a.
According to an example embodiment, the stopper 27 is located on the back wall 26 and is configured to be in contact with the left upper opening wall 15a, and a height, a depth, and/or a width of the stopper 27 is at least 2 mm.
An example of Fig. 3 shows schematically cross-sectional side view of the triangular stopper 27 of Fig. 2b in the tension position.
According to an example embodiment, the bottom flange 9 comprises a flange chamfer 28 comprising a bottom chamfer height BH, and a bottom chamfer width BW. The triangular stopper 27 may comprise a lock chamfer 29, a lock chamfer height LH, and a lock chamfer width LW. The lock chamfer height LH and/or the lock chamfer width LW may be greater than the bottom chamfer height BH and/or a bottom chamfer width BW. This may allow the stopper 27 to form the back wall clearance X1.
According to an example embodiment,the lock chamfer height LH is at least 7 mm; and/or the lock chamfer width LW is at least 7 mm.
The container lock 1 may have different kind of stoppers 27 as long as they form the back wall clearance X1. According to an example embodiment, the rectangular stopper comprises a rectangular height, and a rectangular width, and the rectangular height is at least 3 mm and/or the rectangular width is at least 3 mm. The rectangular height may be measured from an upper surface of the central flange 3. The rectangular width may be measured from the back wall 26 of the container lock 1.
Fig. 4 illustrates an example of a method for joining together an upper container 5 and a lower container 6 stacked on top of each other with a locking arrangement. The locking arrangement may comprise a lower corner piece 7 of the upper container 5 comprising a bottom flange 9 and an upper opening 8 comprising a left upper opening wall 15a and a right upper opening wall 15b; an upper corner piece 10 of the lower container 6 comprising a top flange 12 and a lower opening 11 comprising a lower opening wall 24; and a container lock 1 for locking to each other the lower corner piece 7 and the upper corner piece 10, wherein the container lock 1 may comprise a front wall 25, a back wall 26, a central flange 3, and a stopper 27.
At operation 400, the method may comprise limiting, by the stopper 27, horizontal direction movement, wherein a horizontal direction X is from the front wall 25 to the back wall 26.
At operation 410, the method may comprise preventing, by the stopper 27, the back wall 26 to contact with the left upper opening wall 15a.
At operation 420, the method may comprise forming, by the stopper 27, a back wall clearance X1 between the back wall 26 and the left upper opening wall 15a.
Further features of the method directly result from functionalities of, for example, the locking arrangement. Different variations of the method may be also applied, as described in connection with the various example embodiments.
The locking arrangement for joining together an upper and a lower container stacked on top of each other may be configured to perform or cause performance of any aspect of the method(s) described herein.
Any range or device value given herein may be extended or altered without losing the effect sought. Also, any embodiment may be combined with another embodiment unless explicitly disallowed.
Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims.
It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to 'an' item may refer to one or more of those items.
The steps or operations of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may be deleted from any of the methods without departing from the scope of the subject matter described herein. Aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further embodiments without losing the effect sought.
The term 'comprising' is used herein to mean including the method, blocks, or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements.
Although subjects may be referred to as 'first', 'second', or 'third' subjects, this does not necessarily indicate any order or importance of the subjects. Instead, such attributes may be used solely for the purpose of making a difference between subjects. It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from scope of this specification.

Claims

A locking arrangement for joining together an upper container (5) and a lower container (6) stacked on top of each other, wherein the locking arrangement comprises
a lower corner piece (7) of the upper container (5) comprising a bottom flange (9) and an upper opening (8) comprising a left upper opening wall (15a) and a right upper opening wall (15b);

an upper corner piece (10) of the lower container (6) comprising a top flange (12) and a lower opening (11) comprising a lower opening wall (24); and

a container lock (1) for locking to each other the lower corner piece (7) and the upper corner piece (10), wherein the container lock (1) comprises a front wall (25), a back wall (26), a central flange (3), and a stopper (27), wherein the stopper (27) is configured to
limit horizontal direction movement, wherein a horizontal direction (X) is from the front wall (25) to the back wall (26);

prevent the back wall (26) to contact with the left upper opening wall (15a); and

form a back wall clearance (X1) between the back wall (26) and the left upper opening wall (15a).
The locking arrangement according to claim 1, wherein
the locking arrangement has a front wall clearance (X2) between the front wall (25) and the right upper opening wall (15b);

in a tension position, the back wall clearance (X1) is greater than the front wall clearance (X2); and

in the tension position, the container lock (1) located between the upper container (5) and the lower container (6) is configured to be under an upward tension stress (T), when the container lock (1) is located on the right side of a container stack (31) and the container stack (31) is heeling to the left.
The locking arrangement according to claim 2, wherein the back wall clearance (X1) is greater than the front wall clearance (X2), when
a central flange top surface (20) is configured to be in contact with a bottom flange bottom surface (21); and

the container lock (1) is configured to be pushed in the horizontal direction (X).
The locking arrangement according to claim 2 or 3, wherein in the tension position the lock arrangement is configured to fulfil a formula wherein a tension clearance TC = Y1 - Y0, wherein
Y1 is a vertical distance between a bottom flange bottom surface (21) and a top flange top surface (23) ;

Y0 is a thickness of a central flange (3);
wherein

the tension clearance (TC) is a total vertical clearance generated by the upward tension stress (T) from the upper container (5); and

the tension clearance (TC) is from 0 to 15 mm.
The locking arrangement according to claim 4, wherein the tension clearance (TC) is from 4 to 14 mm.
The locking arrangement according to any of the preceding claims, wherein the container lock (1) is a fully automatic lock.
The locking arrangement according to any of the preceding claims, wherein a body of the container lock (1) is made of one piece.
The locking arrangement according to any of the preceding claims, wherein
the back wall (26) comprises the stopper (27),
and/or

the stopper (27) is located on the central flange (3).
The locking arrangement according to any of the preceding claims, wherein the stopper (27) is located above the central flange (3) and/or on the back wall (26).
The locking arrangement according to any of the preceding claims, wherein
the stopper (27) is located on the back wall (26) and configured to be in contact with the left upper opening wall (15a); and

a height, a depth, and a width of the stopper (27) is at least 2 mm.
The locking arrangement according to any of the preceding claims, wherein the stopper (27) has a triangular or rectangular form.
The locking arrangement according claim 11, wherein
the bottom flange (9) comprises a flange chamfer (28) comprising a bottom chamfer height (BH), and a bottom chamfer width (BW);

the triangular stopper (27) comprises a lock chamfer (29), a lock chamfer height (LH), and a lock chamfer width (LW); and

the lock chamfer height (LH) and/or the lock chamfer width (LW) is greater than the bottom chamfer height (BH) and/or a bottom chamfer width (BW).
The locking arrangement according claim 12, wherein the lock chamfer height (LH) is at least 7 mm and/or the lock chamfer width (LW) is at least 7 mm.
The locking arrangement according claim 11, wherein
a rectangular stopper comprises a rectangular height, and a rectangular width; and

the rectangular height is at least 3 mm and/or the rectangular width is at least 3 mm.
A method for joining together an upper container (5) and a lower container (6) stacked on top of each other with a locking arrangement comprising
a lower corner piece (7) of the upper container (5) comprising a bottom flange (9) and an upper opening (8) comprising a left upper opening wall (15a) and a right upper opening wall (15b);

an upper corner piece (10) of the lower container (6) comprising a top flange (12) and a lower opening (11) comprising a lower opening wall (24); and

a container lock (1) for locking to each other the lower corner piece (7) and the upper corner piece (10), wherein the container lock (1) comprises a front wall (25), a back wall (26), a central flange (3), and a stopper (27), wherein the method comprising

limiting, by the stopper (27), horizontal direction movement, wherein a horizontal direction (X) is from the front wall (25) to the back wall (26);

preventing, by the stopper (27), the back wall (26) to contact with the left upper opening wall (15a); and

forming, by the stopper (27), a back wall clearance (X1) between the back wall (26) and the left upper opening wall (15a).