WO1996015053A1

WO1996015053A1 - Container locking device

Info

Publication number: WO1996015053A1
Application number: PCT/SE1995/001337
Authority: WO
Inventors: Björn Samuelsson
Original assignee: All Set Marine Lashing Ab
Priority date: 1994-11-11
Filing date: 1995-11-10
Publication date: 1996-05-23
Also published as: PL320535A1; WO1996015052A1; EP0790944A1; CZ142097A3; HUT78066A; AU4680496A; EE9700212A; AU1079995A

Abstract

A container locking device (1, 2, 3, 4, 5, 6, 7) of twistlock type having upper and lower connectors (2, 3) on a common shaft (7) rotatably arranged in a housing (1), the lower connector (3) providing a movable latch nose (3; 33). The locking device allows for a straight vertical put-down and locking during loading of a container, and automatic release thereof at the non-accessible container end of a container stack. Secured locking with decreased vertical clearance is achieved.

Description

CONTAINER LOCKING DEVICE

FIELD OF TECHNOLOGY

The invention is related to a container locking de¬ vice of t istlock type for lockingly interconnecting stacked containers, for locking containers to the deck of a ship, etc, using the container standard corner boxes and the elongated openings thereof, comprising a twistlock housing, an upper and a lower twistlock connec¬ tor carried by a common shaft extending through the hous¬ ing, the upper connector being spring biased towards a locking position, and being rotatable to an unlocked po¬ sition by rotating the shaft using the lower connector as a handle, said housing being provided with upright upper and lower neck means for penetrating into a respective box opening and for fittingly interacting therewith. The invention also relates to use of the inventive lock¬ ing device for locking upper and lower containers, of which, after stacking, one end is freely accessible and the other end is substantially non-accessible.

TECHNICAL BACKGROUND AND PRIOR ART

Containers of the actual type have two standard sizes with a length of 20 foot or 40 foot. When trans¬ ported on ships, but also when handled on docks, quays, in storing houses etc, the containers are normally stacked on top of each other. A modern container ship has a capacity of 4000 TEU, Twenty-foot Eqvivalent Units, that is 4000 containers of 20 foot-length type. In the near future we will see container ships having a capacity of 6000 TEU, a lenght of about 300 and a width of about 42 m. The stacking height is 10-15 containers, ^"each hav¬ ing a height of 2,5 m, i.e. a total of more than 25... m. As a consequence it is a prime demand that the containers must be safely secured to each other and to the deck of the ship in order not to slide or become offset, for ex¬ ample during rough weather conditions.

The so called corner boxes or castings provided in each corner of the container, these boxes being standard- ized as well as openings thereof, are used for locking and lashing the containers.

During the years a number of different locking de¬ vices has been developed for interconnecting the contain¬ ers to each other by using the corner box openings on the upper and lower side of the container. One type of a locking device, which has been frequently used during the years is the so called twistlock. A com om type twistlock comprises a twistlock housing having a base plate on which the upper container rests against the lower con- tainer, said base plate being provided with upper and lower upright neck means which fit into said openings, upper and lower rotateable locking cones which, after having been introduced into said openings, will grip un¬ der an adjoining surface of the box, and an operating means for bringing said locking cones to unlocked posi¬ tions. In a normal operation, when loading a container, one twistlock is secured in each of the underside boxes of the hanging container, which is thereafter put on- top of a lower container, the lower twistlock cones being thereby rotated by interacting with the openings of a lower container boxes, and automatically back-rotated into a locking position by a biasing force after being properly introduced into the box. During unloading, the lower locking cone is brought to its unlocked position by using said operating means, thereafter the upper con¬ tainer is lifted and brought to the dock area, well there the twistlocks are released from the hanging container. As well, this procedure illustrates a generally preferred method for handling the locking devices. One locking device of this type is the ALL SET C5AM twistlock, manufactured and sold by the applicant. This twistlock has been disclosed in the international patent application WO92/05093, equivalent to SE Patent No. 9003041-1. In this twistlock said operating means com¬ prises a flexible wire handle. The twist or locking cones, which are spring biased towards a locking posi- tion, may be rotated by pulling this handle into differ¬ ent defined positions. The handle may be operated from deck by the use of a so called actuator pole.

A specific problem arises when the containers are stacked very closely to each other, which means that it may be more or less impossible to release the twistlock at the closely situated ends of the containers by the use of said actuator pole from ground. This may necessitate that said wire handle is operated from the top of the stacked containers, which means in turn that a person would have to climb on the uppermost container. Because of the high risks of accidents involved therewith, it is nowadays becoming a general authority requirement in sev¬ eral countries that this job situation is not acceptable. As such it is as well time consuming and ineffective. The situation of closely positioned containers ap¬ pears when using 20 foot containers within deck loading areas fitted for 40 foot containers, or in case one 40- foot container is loaded on top of two 20-foot contain¬ ers. Accordingly, two 20-foot containers are to be placed within the same area as one 40-foot container, having the consequence that an intermediate gap of only 3 inches will remain between the close ends of the two 20- foot containers.

In order to overcome this problem has been proposed a use of conventional twistlocks of the type as described above at the freely accessible end of the container, and locking means of a so called "rigid type" at the none- accessible end of the container. A said rigid type lock¬ ing means has the general feature that it will automati- cally slide into engagement when putting down the upper container, respectively slide out of engangement when lifting the container after the conventional twistlocks have been unlocked.

A rigid type locking means is disclosed in US patent 3,973,684. This locking means comprises a planar base member with an upright post connector having a ramped sliding surface, and on the opposite side of said base member a flanged foot connector. When used, the foot con¬ nector is introduced into a corner box of the lower con¬ tainer, thereafter the locking means is rotated round its vertical axis, thereby engaging its flanges with the in¬ terior of the corner box. When the upper container is put down, said post connector penetrates into the openings of the upper container, and by sliding on said sliding sur¬ face a free end of said post connector is brought into a vertical opening of the corner box. A rigid locking means of similar type is marketed by the company Peck & Hale under the name "Lock-Matic Stacker F733"; still another by the company Ceman- under the name "Selflock G3.7"; yet another by the company International Lashing Systems America Inc. under the name "Self-locating Stacker IF-

14". All of these rigid type locking means have the major disadvantage that the same in a first step are attached to the top boxes of the lower container, and thereafter the upper container is put down thereon. When unloading the containers these locking means will have to be re¬ leased from the container by a person working on top of the container, being, as mentioned above, a risky and in¬ effective operation. Conclusively, these locking means are not fitted for the preferred method for handling the locking devices during loading and unloading.

The so called "Automatic fixing cone AFC-1" marketed by Conver OSR GmbH represents a different approach of a rigid type locking means, comprising a housing having fixed upper and lower connectors, each connector being provided with fixed nose elements extending in the longi¬ tudinal direction of the corner box opening, a locking element being provided for preventing longitudinal move- ment. When in use, the upper connector is introduced into a corner box at the "non-accessible" end of the hanging container until the nose element of the upper connector has penetrated into said vertical box opening. In this position said locking element is brought to a locking po¬ sition, thereby securing the locking means in the corner box by preventing the same from sliding along the open¬ ing. When the upper container is put down on the lower container said lower connector slides via an inclined surface thereof on the front end edge of the box opening, thereby moving the container longitudinally untill the nose element thereof may pass into the opening. Thereaf¬ ter the container moves longitudinally in the opposite direction and thereby brings the nose element of the lower connector into its locking position in a vertical opening of the lower container, and as a last step the common twistlocks at the other end of the container are brought into grip with the respective corner boxes of the lower container. During unloading, the nose element of the lower connector may slide out of engagement after having released the twist locks at the opposite container end.

Accordingly, this locking means demands a defined sequence of "interlocking steps" during loading, in the sense that the nose element of the lower connector must achieve its locking position before the twist locks at the opposite end come into grip, because otherwise the container may not move longitudinally and allow the fixed nose element to pass into the lower corner box. There- fore, this locking means requires an almost perfect hori¬ zontal position of the ship, which may change during loading. Expressed in other words, the operabability of this lock during loading depends on both "trim" and "list" of the ship, which is clearly disadvantageous. An- other drawback being that said locking element is rather fragile and small and therefore difficult to operate with rough workgloves on your hands. Yet another drawback is that the lock shows a substantial clearance in the verti¬ cal direction.

European patent application No. 91116305.3, appli¬ cant Conver OSR GmbH, discloses a modified version of the "Automatic fixing cone" described above. According to this version the upper and lower connectors are made in one piece which is moveable along an elongated, vertical through-hole in said housing, said unit being biased in the direction of said nose elements. Also in this case a locking element is used for locking the position of the housing in the longitudinal direction of the upper con¬ tainer opening after the upper connector has been prop¬ erly introduced therein. The design is relatively compli¬ cated as consisting of numerous components, some of which have comparatively small dimensions, and therefore not very well fitted for the relatively low precision manu- facuturing methods which are preferably used, involving casted and forged elements. A common disadvantage of this version and the one described above is the fact, that said locking element, being a relative fragile component, will have to withstand the longships horizontal forces acting upon the housing when the lower connector slides into its locking position, this "negative feature" being a direct consequence of the design concept, requiring that the upper fixed connector needs to be rotatable in the box opening by rotating the housing for its attach¬ ment therein. Therefore, it is not possible to have an upright neck means, which fits into said opening, on the upper side like on the lower side of the housing base plate. In combination these shortcomings may explain the fact that the last described version has not appeared on the market.

One object of invention is to obtain a locking de¬ vice not showing the drawbacks of prior art devices as described above. Another object is to obtain a locking device of a design making it possible to use a preferable and safe method for handling the same during container loading and unloading. Still another object is to obtain a locking device of a design making it possible to main¬ tain the benefits as to costs and relibility of using casted and forged components therein. Other objects of invention and advantages obtained thereby will be evident from the following desciption.

SHORT DESCRIPTION OF THE INVENTION

Said objects are obtained by a locking device ac- cording to the opening paragraph of this specification wherein said lower connector provides a latch nose ex¬ tending transversally in relation to said shaft, and, when the upper connector takes its locking position in an upper container corner box, said latch nose extending in the longitudinal direction of said opening and being, in the same direction moveable in relation to said shaft for lockingly engaging the corner box of a lower container. The inventive locking device has the advantages, that the upper container may be put down straight vertically and released simply, after having disconnected the opposite end twist locks, by the nose sliding out of engagement, and that the user ergono y is good because, when attach¬ ing the locking device in the underside corner boxes of a hanging container, a twister operation may be used for bringing the upper connector to its unlocked position which is the same as used for the twist locks at the op¬ posite end of the container, in both cases using the lower connector as a handle. This eliminates confusion when the locking devices are secured respectively re- leased in the quay area. Another advantage being that the basic design and throuroughly tested design elements of the common twist lock may be used to a large extent.

According to a preferred embodiment of the inventive locking device said movable latch nose is elastically bi- ased in its movement direction. The biasing automatically brings the latch nose into grip with the adjoining sur¬ face part of the corner box. Another preferred embodiment, in which said lower connector has a generally cone-shaped body of which the base adjoins the housing, has the characterizing feature that the latch nose is provided by a front end part of the cone base, which is moveable in relation to the ver¬ tical shaft. In a first version thereof the latch nose is formed by a base part of said cone body shaped as a trun¬ cated cone, which is moveably attached to the shaft via an oblong vertical hole therein. According to a second version thereof the lower end of the shaft is provided with a horizontal spindle to which the cone shaped body is attached via oblong recesses. In these two versions, when a downward force acts upon the latch nose end, said truncated cone part or said cone-shaped body will tilt around said spindle and said force will be taken up at the contact surface between an upper rear end part thereof and the housing. This has the advantage that a bending torque will not be transferred to the shaft end. In a preferred embodiment said rear end contact surface provides a frictional surface which is pressed against the housing by a lifting force acting upon the locking device. The friction created thereby secures the engage¬ ment position of the latch nose.

Preferably in said two versions, the shaft is verti- cally moveable, and said truncated cone part alterna¬ tively said recesses have a "widening-wedge function" in the nose engagement direction. From this follows, when the latch nose moves in the engagement direction, that the shaft will be moved downwardly by said wedge func- tion, thereby decreasing the overall vertical clearance of the locking device. This feature generally improves and safeguards the interconnecting function of the lock¬ ing device and may be specifically important in relation to high container stacks. Further preferred embodiments of the inventive lock¬ ing device are evident from the following claims. Throughout this specification and the claims expres¬ sions like "horizontal", "vertical", "upper", "lower" have been used as refering to the normal use situation of the locking device in order to clarify the description and thereby to facilitate an understanding of the inven¬ tion. It is emphasized, however, that these expressions are not to be conceived in any sense of limitation.

The invention will be closer described in the fol¬ lowing by exemplifying non-limiting embodiments with ref- erence to the drawings.

SHORT DESCRIPTION OF THE DRAWING FIGURES

Fig. 1 discloses a perspective view of a prior art conventional twistlock. Fig. 2 discloses a first embodiment of the locking device according to the invention in its interacting po¬ sition with a container corner box.

Fig. 3a, b, c disclose a second embodiment of the invention in a side view, a view from above respectively a sectional view.

Fig. 4 discloses a third embodiment of the invention in sideview.

Fig. 5 discloses a fourth embodiment of the inven¬ tion in sideview. Fig. 6 discloses a rear view of a connector or lock¬ ing cone according to the invention.

Fig. 7 discloses the locking device according to Fig. 5 in its interaction position with a container cor¬ ner box. Fig. 8 discloses a view from above of a preferred embodiment of the latch nose connector according to the invention.

Fig. 9 discloses the loading operation of a con¬ tainer. Corresponding elements in different Figures have the same reference numbers. DESCRIPTION OF PRIOR ART TWISTLOCK

The prior art common twistlock in Fig. 1 is illus¬ trated by an ALL SET C5AM twistlock marketed by the ap- plicant. The twistlock comprises a housing 1, an upper twistlock connector or cone 2, a lower connector or cone 3, said cones being rotatably carried by a through-going shaft, which has been illustrated by its rotation axis 7. The housing 1 comprises a base plate 4 on which an upper container rests against a lower container, furthermore upper and lower upright neck means 5 and 6, respectively. The neck means are form-fitted to the horizontal elon¬ gated openings of the container corner boxes, said open¬ ings being shaped in accordance with standard ISO 1161- 1984 (E) . When the twistlock is used the neck means 5, 6 penetrates into the corner box openings, thereby defining the horizontal position of the twistlock and picking up horizontal forces acting on the same. The housing 4 con¬ sists of two vertical sections as indicated by the line 8, the sections being put together by means of bolts 9. By means of a flexible wire handle 10 said locking cones may be rotated into locked and unlocked positions.

According to the invention this kind of a twistlock is used at the corner boxes of the freely accessible con- tainer end with the handle 10 directed towards the free front end of the container.

In Fig. 1 the upper cone 2 has been shown in its locked position, that is transverse to the longitudinal direction of the neck 5 as well as the interacting box opening. By means of a spring arranged inside the housing 4 cone 2 is biased towards the disclosed position. Using the lower cone 3 as a handle the upper cone 2 may be ro¬ tated against said bias by means of the common shaft into its unlocked position, that is along the neck 5. In this position the cone 2 and the neck 5 may be introduced into a box opening of a hanging container, and when the lower cone 3 is released the upper cone 2 automatically rotates back into its locked position by said biasing spring.

For further details of construction as well as the use of the handle 10 is referred to WO92/05093. General features of this twistlock are that the wire handle thereof is flexible and thereby unbreakable, and that it is composed of a relatively low number of component parts, of which the housing and the shaft are made from forged steel. Fig. 2 discloses a first embodiment of the locking device according to the invention in sideview after hav¬ ing been introduced into the corner boxes of an upper container CI respectively a lower container C2, of which the corner box 11 has been schematically shown in sec- tion. The box corresponds with said ISO standard and has an edge 12 at the front end of the elongated opening in its roof. The underside of the edge part 12 provides for an engagement surface for the moveable latch nose accord¬ ing to the invention. The locking device comprises an upper connector 2 of the same kind as disclosed in Fig. 1, a base plate 4 ex¬ tending outside the front 13 of the container CI and ended by an erect element 14. The erect element 14 elimi¬ nates the risk of introducing the locking device into the underside boxes of a hanging container 180° wrong. The base plate 4 has upper 5 and lower 6 neck means which are form-fitted to the box openings. The lower connector 3 has a movable latch nose 15, in this embodiment shaped as a swingable element, which may be rotated around a hori- zontal spindle 16 directed transverse to the plane of the drawing.

Like in Fig. 1 the upper and lower connectors 2 and 3 are arranged on a common rotatable shaft, and the con¬ nector-shaft structure is biased towards ^'the disclosed position, in which the upper connector 2 takes its locked position transverse to the box opening and the lower con- 5053

nector 3 is positioned longitudinally with the box open¬ ing.

The swingable nose element 15 is provided in a form- fitted slot of the connector body and has been shown in its folded-out locking position. When the lower connector 3 successively penetrates into the box opening, the swin¬ gable nose element 15 slides against said edge part 12 and is thereby folded into said slot, preferably against a biasing force from a spring or a similar elastic member (not shown) . After having passed the edge part 12 the nose element 15 is automatically moved/swung to its lock¬ ing position as shown.

From the side view in Fig. 3a of a second embodiment of the locking device according to the invention is clear that the device is made up by an upper connector 2, a housing with base plate 4 and upper and lower neck means 5 and 6, the base plate being extended into an erect ele¬ ment 14, in correspondence with what has been shown in Fig. 2. Like in Fig. 1 the housing sections has been put together by means of bolts 9. The lower connector is pro¬ vided with a movable latch nose shaped as a nose rod 17, which is accommodated and slidingly fitted into a hori¬ zontal recess in the connector body. The nose rod 17 is biased in its engagement direction (to the right on the drawing) by means of a helical spring 18. Like in other embodiments this spring may be replaced with a corre¬ sponding elastic member, for example a shaped piece of rubber. Preferably the nose rod 17 has a generally quad¬ ratic transverse section. In its front end the nose rod is provided with an inclined surface 19, allowing the nose rod to be retracted into the connector body by slinding against said edge part 12. The rear side 20 of the connector cone 3, as well as the adjoining rear end side of the lower neck means 6, is inclined in order to improve the performance of the locking device when it is lowered into engagement with the corner box of a lower container, as well as when lifted out of engagement. 13

The view from above in Fig. 3b shows that the exten¬ sion of the base plate 4 has been shaped into a semi¬ circular element 22, which may be used as a handle.

Fig. 3c shows a sectional view along line A-A in Fig. 3a, disclosing the interior of the housing with the vertical shaft 7 carrying a stop arm 23, abutting a stop element 24 of the housing, together defining the angular position of the shaft and thereby the positions of the upper and lower connectors 2, 3 as shown in Fig. 3a, b. A helical spring 25, provided on the shaft, biases the shaft into the position as shown.

Fig. 4 discloses a side view of a third embodiment of the locking device according to the invention, having an upper connector 2, a housing with a base plate 4 and an upper 5 and a lower 6 neck means, and a through-going vertical shaft indicated by its axis of rotation 7, all in correspondence with the embodiment of Fig. 3a. The view from above and the sectional view along line A-A are identical with Fig. 3b and 3c, respectively. The lower connector or locking cone has been hori¬ zontally divided into a truncated-cone shaped base part 26, providing the moveable latch nose thereof, and a top part 27 fixed to low end of shaft 7 and holding part 26 in place. The truncated-cone part 26 has a through-going, vertical hole, the horizontal extension of which has been indicated by the dotted lines 28. The shaft passes through said hole, thereby allowing the nose part 26 to slide thereon in the horizontal direction. A biasing helical spring 30 is provided on a horizontal pin 29, which is fixed to the shaft, said spring 30 continuing into a recess into which the pin 29 penetrates when the nose part 26 is moved. This movement (to the left on the drawing) takes place when the connector is introduced into the corner box opening by sliding the inclined sur- face 19 of the nose part 26 against box edge part 12. Af¬ ter having reached its vertical locking position the nose part 26 is automatically pushed back (to the right on the drawing) into engagement by the spring 30. Also in this case inclined surfaces 20 and 21 are provided on the rear ends of the nose part 26 respectively the lower neck means 21 of the same reasons as already set forth above. The oblong vertical opening of the nose part allows tilting of the nose part 26 when the engagement nose end 31 thereof is pressed downwards by a lifting upper con¬ tainer. Important is that the tilt movement of the nose part 26 takes place without the transfer of a torque to the shaft 7, thereby eleminating bending forces on the same. Instead the torque will be taken up by the upper rear end surface 32 of the nose element 26, being pressed into contact with the adjoining surface of the housing. In turn this creates friction between the nose element 26 and the housing which secures the horizontal position of the nose element and thereby its engagement under said box edge part 12.

The truncated-cdne shaped nose element 26 has a wedge shape in the plane of the drawing which narrows in the direction of the nose 31. When the nose moves into engagement (to the right on the drawing) said wedge wid¬ ens successively and creates thereby, via part 27, a pulling force on the shaft 7, moving the shaft and the upper connector 2 downwards. From this movement of the shaft follows that the upper connector 2 will be tight¬ ened against the interacting box surface, thereby reduc¬ ing the vertical clearance of the locking device.

Fig. 5 discloses a fourth embodiment of the locking device according to the invention, comprising a housing with base plate 4, upper and lower neck means 5 and 6 and the extension 22 with the erect element 14, as well as an upper connector 2, all in correspondence with the embodi¬ ments disclosed in Figures 3 and 4. This embodiment has as well the same view from above and sectional view as shown in Figures 3b, c.

The lower connector 3 comprises a connector body with an inside cavity indicated by the dotted line 34. This cavity may be open at the rear end of the connector body, having the inclined sliding surface 20. The lower end of the shaft 7 is formed into an apertured ring 35. Each of the opposite side walls of said cavity have an oblong through-hole 36. The connector body is attached to the ring-shaped shaft end by means of a horizontal spin¬ dle 37 directed transversally to the plane of the draw¬ ing, which penetrates said oblong holes 36 and the apper- tured ring 35. A biasing spring 30 is arranged in an ex- tended part of the cavity and rests against the ring 35, thereby biasing the connector in its nose engagement di¬ rection.

The spindle 37 allows for a tilt movement of the connector body when influenced by a pressure force on its nose engagement surface 33. In correspondence to what has been described in relation to the embodiment of Fig. 4 the torque is taken up at the contact surface between the rear upper part 32 of the connector body and the opposite surface of the housing. Again friction is created at said place of contact, which secures the engagement position of the latch nose, and furthermore makes it possible to use a more inclined and rounded engagement part 33 of the nose, which in turn creates a close fit to the shape of the engagement surface of the corner box, thereby allow- ing the nose to penetrate as far as possible under said edge part 12. As well the sloped nose has positive ef¬ fects on the performance when sliding the latch nose out of grip.

Said oblong holes 36 are inclined in the nose en- gagement direction in order to obtain a wedge function which in similar manner as described above creates a pulling force on the shaft 7 and thereby decreases the vertical clearance of the locking device.

Fig. 6 discloses a rear end view of the connector body 3 as shown in Fig. 5. From this view is clear that the connector body is cone-shaped in this direction of view as well. The extended part of the cavity, in which t 6 the biasing spring 30 is situated, has been indicated by a circle. Furthermore is illustrated that said cavity is open towards the rear end of the body having the inclined surface 22. In a modified embodiment said cavity may be closed in all directions but upwards in order to obtain a smooth outside surface of the cone body.

Fig. 7 illustrates the locking device of Fig. 5 in its interlocking position between containers CI och C2. The Figure illustrates that the inclined surface 33 ad- mits a close fit of the latch nose to the rounded or in¬ clined clearance surface 38 of the box edge part 12, partly penetrating a vertical, front end corner box open¬ ing. In combination with the wedge-function of the in¬ clined holes/recesses 38 this effect further reduces the vertical clearance and provides for a close contact at the resting surfaces 39 and 40 between the upper and the lower container boxes and base plate 4.

Fig. 8 illustrates a preferred embodiment of the connector 3, which is manufactured from an U-bent steel element, which is U-shaped after having prepared the ob¬ long holes/recesses 36 (see Fig. 5) . The latch nose is formed by the base of the U. Using this manufacturing method the lower end of the shaft 7 may be shaped as a "T" of which the horizontal bar forms said spindle 37 marked by dotted lines. The T-bar may be introduced into said holes 36 while bending the U.

In Fig. 9, A illustrates the situation when an upper container CI is put down onto a lower container C2. The inventive locking devices have been attached in the cor- ner boxes at the non-accessible end of container CI, and at the opposite end thereof common type twistlocks.

As may be seen from the enlarged partial views the inventive locking device is of the type disclosed in Fig. 3, except for the fact that the housing thereof is shaped in correspondence with the housing of the common type twist lock. As indicated by the black arrow the upper container Cl is put down straight vertically and doing this the latch nose of the inventive locking device oper¬ ates as set forth above, while the common twistlocks op¬ erates in normal fashion.

B, C, D, E, in Fig. 9, illustrate the different steps during loading of a container focusing on measures at the non-accessible end of the container. At B the up¬ per connector is rotated to its unlocked position by ro¬ tating the shaft using the lower connector as a handle; in this position the upper connector and the adjacent up- per neck means are introduced into the box opening of the hanging container; the lower connector is released, which makes the upper connector rotate into its locked position thereby securing the locking device to the corner box as illustrated at C. Thereafter the container is lifted on board by means of a crane and put down straight verti¬ cally on a lower container as illustrated at D. The lower connectors penetrate into the corner boxes of the lower container and automatically interlock the containers to each other as illustrated at E. An alternative way of use of the inventive locking device is for locking a container to the deck. In this situation the locking device is turned upside down by firstly introducing the upper connector 2 into a corre¬ sponding ISO socket. Thereafter the container is put down onto the latch nose connector 3.

It is understood that a man skilled in the art may propose alternative solutions with respect to construc¬ tional details of the locking device as described, all within the general scope of invention. Therefore, what has been described in these respects is to be conceived as non-limitative examples.

Claims

t 8 .CLAIMS

1. A container locking device of twistlock type for lockingly interconnecting stacked containers, for locking containers to the deck of a ship, etc, using the container standard corner boxes (11) and the elongated openings thereof, comprising a twistlock housing (1), an upper and a lower connector (2, 3) carried by a common shaft (7) extending through the housing, the upper con- nector being rotatably spring biased (25) towards a lock¬ ing position and being rotatable to an unlocked position by rotating the shaft using the lower connector as a han¬ dle, said housing being provided with upright upper and lower neck means (5, 6) for penetrating into a respective box opening and formfittingly interacting therewith, c h a r a c t e r i z e d by

- said lower connector (3) providing a latch nose (15; 17; 31; 33) extending transversally in relation to said shaft, and, when the upper connector takes its locking position in an upper container corner box,

- said latch nose extending in the longitudinal direction of said opening and being, in same direction, movable in relation to said shaft for lockingly engaging the corner box of a lower container.

2. A locking device as claimed in claim 1, c h a r a c t e r i z e d by

- said movable latch nose being elastically biased in its movement direction, thereby, when aligned with said opening and after bringing the lower connector into its proper locking position in the corner box, urging the nose to engage under an edge (12) surface of the corner box at the end thereof which adjoins the short end of the container. ₁₉ PCI7SE95/01337

3. A locking device as claimed in claim 1 or 2, c h a r a c t e r i z e d by

- said latch nose being provided by a swingable nose ele¬ ment (15) hinged (16) at a downward end of the connector, the nose element folding temporarily into the connector body when introducing the connector into the corner box open¬ ing, and folding out when the connector is properly posi¬ tioned in the corner box.

4. A locking device as claimed in claims 1 and 2, c h a r a c t e r i z e d by

- said latch nose being provided by a retractable nose rod (17) accommodated and journalled by a shaped recess of the connector body,

- an inclined sliding surface (19) being provided on a lower side of the nose rod, allowing the nose rod to be retracted into the connector body against said bias by said sliding surface interacting with the corner box opening when introducing the connector therein.

5. A locking device as claimed in claims 1 and 2, said lower connector (3) having a generally cone-shaped body of which the base adjoins said housing (1), c a r a c t e r i z e d by

- said latch nose being provided by a front end part (31; 33) of said cone base, being movable in relation to said shaft (7) and elastically biased in the engagement direc¬ tion.

6. A locking device as claimed in claim 5, c a r a c t e r i z e d by

- said cone comprising 'a base part shaped as a truncated cone (26) and providing the function of the latch nose, and a top part (27) attached to said shaft (7) and hold¬ ing said first part in place, and - said truncated cone part (26) being movably arranged on said shaft by a trough-going generally vertical bore (28) having a horisontal extension allowing for the nose to be moved by said bias and engaged with the corner box.

7. A locking device as claimed in claim 5, said common shaft (7) being vertically movable in said housing (1), c h a r a c t e r i z e d by

- said truncated cone part (26) having, in vertical sec- tion, a wedge-shape, which narrows in the nose direction, thereby successively reducing the vertical clearance of the locking device when the nose moves into engagement.

8. A locking device as claimed in claim 5, c h a r a c t e r i z e d by

- said cone-shaped body (3; Fig. 5) being provided with a cavity (34) which is open at least upwards,

- the lower end of said shaft (7) being provided with a horizontal spindle (37) transversal to the nose engage- ment direction, and

- the ends of said spindle being slidingly fitted into oblong recesses (36) in opposite side walls of said cav¬ ity, thereby attaching the connector body to the shaft end movably in the nose engagement direction.

9. A locking device as claimed in claim 8, said common shaft (7) being vertically movable in said housing (1) , c h a r a c t e r i z e d by

- said recesses (36) being inclined in the nose direc- tion, thereby providing a wedge-function successively de¬ creasing the vertical clearance of the locking device when the nose moves into engagement.

10. A locking device as claimed in 8 or 9, c h a r a c t e r i z e d by

- said shaft end being shaped as a ring (35) with a cen¬ tral aperture, - said connector body being provided by an U-bent, pref¬ erably forged element, the base of the U forming said nose,

- through-going holes in the U-legs forming said re- cesses, and

- said spindle (37) penetrating the apertured ring (35) and said recesses.

11. A locking device as claimed in anyone of claims 8, 9, 10 c h a r a c t e r i z e d by

- said base of the cone-shaped connector body having a rear end at the side of the shaft which is opposite to the nose end side thereof, - when a lifting force acts upon the locking device, said rear end providing a frictional surface (32) pressed against said housing by a tilt action of the connector body around said spindle (37), thereby securing the nose engagement.

12. A locking device as claimed in anyone of the previ¬ ous claims, c h a r a c t e r i z e d by

- said latch nose having an inclined upper latch surface (33), providing, in relation to said shaft, a generally outwardly and downwardly inclined sliding surface allow¬ ing the nose to fit into and slide out of engagement with the lower container upon putting down respectively lift¬ ing the upper container.

13. A. locking device as claimed in anyone of the previ¬ ous claims, .said housing comprising a horisontal base plate (4) and upper and lower upright neck means (5, 6) joined therewith defining the position of the locking de- vice in relation to said box openings, c h a r a c t e r i z e d by - said base plate, at the side thereof which is turned to the end of the container, being provided with an erect element (14) protruding transversally to said base plate and so positioned that it appears outside the front of the container when the locking device has been properly introduced into an upper container box, thereby eliminat¬ ing the risk of incorrect introduction into the corner boxes.

14. A use of the inventive locking device for locking upper and lower containers, of which, after stacking, one end is freely accessible and the other end is substan¬ tially non-accessible (Fig. 9), whereas, on the underside of the upper container, - actuator operable twistlocks are secured in the corner boxes of the freely accessible end, and inventive locking devices are secured in the corner boxes of the "non- accessible" end with^'the latch nose connector facing downwardly, the upper connectors of the inventive locking devices, and preferably the tv.'istlocks as well, being ro¬ tated by hand to an unlocked position using the lower connector as a handle, thereafter introduced into respec¬ tive openings, released and automatically twisted to the locked position by said bias, thereby - allowing the downwardly facing connectors to be inter¬ locked automatically into the corner boxes of the lower container by putting down the upper container straight vertically, and, after having unlocked said twist locks by operating said actuator,

- allowing the freely accessible container end to be lifted, thereby somewhat tilting the container, and slid¬ ing the "non-accessible" end latch nose connectors out of engagement.