EP3670386A1 - Coupling piece for connecting two stacked containers - Google Patents

Abstract

The invention relates to a coupling piece (10) for connecting two containers stacked one above the other, in particular on board ships, with a first coupling projection (11), which is designed to engage and pre-lock in a corner fitting of a first container, and a second coupling projection (12 ), which has a shaft (14) and, seen in the longitudinal direction of the containers, a locking lug (15) arranged laterally on the shaft (14) with a shoulder (16) falling away from the shaft (14). In order to further improve the safety of coupling pieces, the coupling piece (10) according to the invention is characterized in that the angle (γ; α, β) of the sloping shoulder (16) to a horizontal plane (20) away from the shaft (14) becomes smaller.

Description

The invention relates to a coupling piece for connecting two containers stacked one above the other, in particular on board ships, with a first coupling projection, which is designed to engage and pre-lock in a corner fitting of a first container, and a second coupling projection, which has a shaft and one in the longitudinal direction seen the container laterally arranged on the shaft locking lug with a shoulder sloping away from the shaft.

Such a coupling piece is from among others EP 1 534 612 B1 but also that EP 1 784 348 B1 or the EP 2 892 828 B1 known, which originate from the applicant. Specifically, it is a so-called fully automatic twistlock (Fully Automatic Twistlock - FAT), which locks a first container fully automatically with a second container when the first container is loaded onto a ship and placed on the second container, and also unlocks again fully automatically , if the first container is unloaded (unloaded) and a crane lifts it from the second container.

Such coupling pieces are used to connect containers transported as a stack of containers to one another on deck (on the hatch cover) of a ship. The containers in the lowest layer and sometimes also with the help of lashing bridges containers in higher layers are additionally secured with lashing rods. Often, however, the coupling pieces are the only safeguards for higher-level containers to prevent them from being lost during sea transport.

When the containers are stowed (loading), the stevedore on the quay first inserts and locks a coupling piece with its first (upper) coupling projection in the four lower corner fittings of a container to be loaded. Now the Containers are hoisted by a crane (container bridge) on the deck of the ship and placed there on an already stowed container. The second (lower) coupling projections thread into the four upper corner fittings of the already stowed container. When the containers are now stacked, the second coupling projections engage in the upper corner fittings of the already stowed, now lower container and secure the new, stowed, now upper container in this way against being lost during the sea transport. This state is referred to as a coupled state in the context of the present disclosure.

During sea transport, lifting movements only occur on one long side of the container due to rolling movements of the ship, while compressive forces arise on the other long side. These compressive forces prevent the upper container from moving horizontally, so that the two coupling pieces on the other long side, on which the lifting forces act, cannot unlock. When the upper container is unloaded (deleted), it is lifted again with a crane. Now tensile forces develop on both long sides of the container, i.e. on all four coupling pieces. As a result, the lower (second) coupling projection can now disengage from the upper corner fitting of the lower container if the oblique shoulder of the locking lug abuts the edge of the elongated hole in this corner fitting. Due to the sloping shoulder, a horizontal force component is created which presses the coupling piece into a position in which it can be threaded out of the corner fitting. This is in the EP 1 534 612 B1 described in more detail.

In the prior art, the upper shoulder ramps outward at a certain angle. As a result, the horizontal force component on the shoulder and thus the coupling piece is the same across the entire depth of the locking lug. There is also a certain vertical play of the lower coupling projection in the associated corner fitting, which must be minimized. The coupling piece designed according to the state of the art cited here has proven to be reliable in years of practice. Nevertheless, it is important to further improve their security.

Proceeding from this, the invention is based on the problem of further improving the security of the coupling pieces mentioned at the outset.

To solve this problem, the coupling piece according to the invention is characterized in that the angle of the sloping shoulder to a horizontal plane becomes smaller away from the shaft.

If the upper container is deleted, the upper shoulder first hits the edge of the slot with its steeper angles. This initiates the unlocking of the coupling piece. If the coupling piece now slides in a direction opposite to the direction in which the locking nose points, the horizontal force component on the upper shoulder becomes smaller. However, this does not strengthen because the unlocking movement has already been initiated. When the ship rolls in the sea, the flatter angle of the upper shoulder on the locking lug comes into play if the upper container and with it the coupling piece move slightly horizontally due to the tolerances allowed. The flatter angle then causes a low horizontal force component due to the lifting forces. At the same time, the vertical play is reduced due to the flatter angle. The risk of unwanted disengagement is further minimized and consequently the safety of the coupling piece is increased.

The angle of the upper shoulder can change continuously. Any contour is conceivable, for example a parabolic or elliptical contour. The shoulder preferably has the contour of a circular arc section. This contour is particularly easy to manufacture. The ratio of a depth of the nose to a radius of the circular arc section should be 1: 1.5 to 1: 3, in particular 1: 2.25. This ensures that there is still a slightly sloping angle at the tip of the locking lug and that the upper shoulder does not run out horizontally.

As an alternative to the continuously changing angle, the angle can also change in one or more steps. For manufacturing reasons, only one step with only one kink between the angles is preferred. In doing so, a level with a a first angle on the side facing the shaft and a second angle on the side facing away from the shaft, the first angle being 20 ° to 40 °, in particular 30 °, and the second angle being 20 ° to 10 °, in particular 15 °, is. The first angle is preferably twice as large, again the second angle.

• Fig. 1 ein erstes Ausführungsbespiel eines Kuppelstücks mit den Erfindungsmerkmalen in Vorderansicht, und
• Fig. 2 ein weiteres Ausführungsbespiel eines Kuppelstücks mit den Erfindungsmerkmalen in Vorderansicht.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawing. The drawing shows:

• Fig. 1 a first embodiment of a coupling piece with the features of the invention in front view, and
• Fig. 2 another embodiment of a coupling piece with the features of the invention in front view.

In the 1 and 2 In each case, an exemplary embodiment for a coupling piece 10 with the features of the invention, namely a so-called fully automatic twistlock (Fully Automatic Twistlock - FAT) is shown. In both embodiments, the coupling pieces 10 each have a first coupling projection 11 and a second coupling projection 12, each of which extends away from a stop plate 13. The stop plate 13 is shown in the present case as a pronounced flange, but can also be reduced to a bead which only engages in a groove which is formed by chamfers on the elongated holes of container corner fittings (not shown) when they lie directly on top of one another.

When loading containers onto a ship, the container is first lifted by a crane on the quay and then a coupling piece 10 is inserted into each of the four lower corner fittings of the container. The first coupling projection is inserted through an elongated hole on the underside of the respective corner fitting. This coupling projection 11 is also referred to as the upper coupling projection 11 in accordance with its usual orientation. Various suitable designs of the first coupling projection 11 are known. The first coupling projection 11 can thus be similar to that in FIG EP 1 784 348 B1 shown upper coupling projection formed and how it is inserted into the lower corner fitting of the container and pre-locked there.

Now the container is hoisted by the crane on board the ship and placed there on an already loaded container. The lower coupling projection 12 of each coupling piece 10 is threaded into the associated elongated hole in an upper corner fitting of the already loaded container and locks there automatically as in FIG EP 1 534 612 B1 described. For this purpose, the second coupling projection 12 (also called lower coupling projection 12) has a shaft 14 formed on the stop plate 12 and a locking lug 15 formed laterally on the shaft 14 as seen in the longitudinal direction of the containers. The locking lug 15 has an upper shoulder 16 that slopes away from the shaft 14. In this respect, they correspond specifically to the 1 and 2 shown second coupling projections 12 of the coupling pieces 10 the lower coupling projection of the coupling piece after the EP 2 892 828 B1 . However, the upper shoulder 16 is designed in a special way according to the invention:
In the embodiment according to Fig. 1 the shoulder 16 falls from the shaft 14 as seen initially with a steeper angle α and then passes over a kink 17 to a flatter angle β. As seen from the shaft 14, the shoulder 16 therefore initially has a steeper shoulder section 18 and a flatter shoulder section 19 delimited by the kink 17. In the context of the present disclosure, “steeper” means that the angle α of the steeper shoulder section to a horizontal 20 is greater than the angle β of the flatter shoulder section 19 to the horizontal 20 (α> β). Conversely, "flatter" means β <α.

The first angle α can generally be between 20 ° and 40 ° and the second angle β between 10 ° and 15 ° to a horizontal. The first angle α is particularly advantageously approximately twice as large as the second angle β (α ≈ 2β). In the specific embodiment shown, the first angle α = 30 ° and the second angle β = 15 ° to the horizontal 20.

In the context of the present disclosure, “horizontal” means a plane which extends parallel to the plane which is defined as your parting plane by the two containers stacked one above the other, and in which the stop plate 13 also extends, as far as in FIGS Shown present embodiment, a stop plate is provided.

In the embodiment according to Fig. 2 the angle of the shoulder 16 changes continuously. Specifically, the upper shoulder 16 follows the contour of a circular arc section with a radius R. Depending on the depth t of the locking lug 15, the radius R is 1: 1.5 to 1: 3 times the depth t. The depth t of the locking lug is the horizontal dimension of the locking lug 15 from a front wall 21 of the shaft 14 pointing towards the locking lug to the outer tip 22 of the locking lug 15.

The above-mentioned size ratio of the radius R to the depth t ensures that the shoulder 16 to the tip 22 of the locking lug 15 always ends at a certain angle γ different from "zero" to the horizontal (γ ≠ 0 °). In the specific embodiment shown, the radius is R = 30 mm at a depth t = 16 mm. The angle γ is 10 ° (γ = 10 °).

When deleting (unloading) the container, the coupling piece 10 also unlocks again fully automatically, as also in FIG EP 1 784 348 B1 described when the container is raised again by a crane. This creates lifting forces on the coupling pieces 10 at all four corners of the container to be deleted. These cause the shoulder 16 to abut an inner edge at the elongated hole of the associated corner fitting. Due to the vertical force, the oblique shoulder 16 also creates a horizontal force component which presses the coupling piece 10 in a direction opposite to the direction in which the locking lug 16 points, as in FIG EP 1 784 348 B1 described. Since the shoulder 16 initially falls off at a steeper angle, the horizontal force component is initially greater. This favors the start of the unlocking process. The horizontal force component then becomes step-like due to the flattening of the shoulder 16 ( Fig. 1 ) or continuously ( Fig. 2 ) smaller. However, this does not harm the unlocking process, since the unlocking process has already been initiated.

During sea transport, lifting movements only occur on one long side of the container due to rolling movements of the ship, while compressive forces arise on the other long side. These compressive forces prevent the upper container from being able to move horizontally, so that the two coupling pieces 10 on the other long side, on which the lifting forces act, cannot unlock. This is where the flatter angle of the shoulder 16 on the locking lug 15 comes into play if the upper container and with it also the coupling piece 10 are shifted slightly horizontally due to permitted tolerances. The flatter angle then causes a low horizontal force component due to the lifting forces. The risk of unwanted disengagement is further minimized.

Reference symbol list:

10th

Coupling piece

11

upper coupling projection

12

lower coupling protrusion

13

Stop plate

14

shaft

15

Locking lug

16

shoulder

17th

Kink

18th

steeper shoulder section

19th

flatter shoulder section

20th

horizontal

21st

Front wall

22

top

α

angle

β

angle

γ

angle

t

depth

R

radius

Claims (7)

Coupling piece (10) for connecting two containers stacked one above the other, in particular on board ships, with a first coupling projection (11), which is designed to engage and lock into a corner fitting of a first container, and a second coupling projection (12), which one Shaft (14) and, seen in the longitudinal direction of the containers, a locking lug (15) arranged laterally on the shaft (14) with a shoulder (16) falling away from the shaft (14), characterized in that the angle (γ; α, β ) the sloping shoulder (16) to a horizontal plane (20) from the shaft (14) away smaller. Coupling piece according to claim 1, characterized in that the angle (γ) changes continuously. Coupling piece according to claim 2, characterized in that the shoulder (16) has the contour of a circular arc section. Coupling piece according to claim 3, characterized in that the ratio of a depth (t) of the nose to a radius (R) of the circular arc section is 1: 1.5 to 1: 3, in particular 1: 2.25. Coupling piece according to claim 1, characterized in that the angle (α, β) changes in one or more steps. Coupling piece according to claim 5, characterized in that the angle changes in one step with a first angle (α) on the side facing the shaft (14) and a second angle (β) on the side facing away from the shaft (14), wherein the first angle (α) is 20 ° to 40 °, in particular 30 °, and the second angle (β) is 20 ° to 10 °, in particular 15 °. Coupling piece according to claim 6, characterized in that the first angle (α) is twice as large again the second angle (β).

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