Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D90/00—Component parts, details or accessories for large containers
  • B65D90/0006—Coupling devices between containers, e.g. ISO-containers
  • B65D90/0013—Twist lock

Definitions

• the present invention relates to a container lock or container coupling tool for locking stacked containers to each other.
• the container lock comprises first and second locking elements capable of being joined to respective locking parts on juxtaposed container corners and rotated to lockingly engage the container corners.
• the present invention relates to a container lock for coupling shipping containers stacked one on the other. In transporting shipping containers, they are often stacked on each other. This is especially the case when the containers are transported by ship. Each container is locked to the containers immediately above and below by container locks (container coupling tools), and the top containers may be fixed to the ship deck.
• container lock that has been proposed is a twistlock that generally comprises a housing with a shaft joumalled through the housing and having a lug or cone on opposite ends of the shaft. The housing is located between adjacent containers and the cone-shaped lugs are locked within a respective corner casting.
• lugs can be inserted through elongate slots of the container corners and then rotated to lockingly engage the container corner.
• Container locks or coupling tools of this kind are disclosed in, for example, US patent No. 5012560, US patent No. 6164862 and US patent No. 6334241.
• a container lock is disclosed that has an upper and a lower locking lug.
• the lower locking lug is translationally mounted in a housing connected to the upper lug and has a shaft capable of limited movement in the axial direction. Between the housing and the shaft, there are guide means which permit a locking rotation of the lower lug on upward movement of the shaft.
• the shaft has a head with a blind bore for receiving an abutment part that forms a centring abutment for a coil spring.
• the coil spring will tension-actuate the shaft and the lower locking lug in a downward direction.
• a locking device is arranged that includes spring-actuated arms that can be pivoted to a position under the head of the shaft and thereby prevent axial movement of the shaft.
• the spring-actuated arms lock the shaft against axial movement, the lower lug cannot be rotated away from locking engagement with the respective container corner.
• an operating rod connected to the arms is pulled out causing the arms to be spread. The operating rod can be acted upon by swinging a U-shaped member.
• the container lock When the container lock is in place between two juxtaposed container corners, the container lock can be opened and closed by the U- shaped member. However, lifting of the lower lug from the bottom of a container corner causes the coil spring to press the head of the shaft downwards into abutment against the spring-actuated arms and cause the operating mechanism to be friction-locked.
• the container locks During unloading of shipping containers, the container locks must be unlocked such that an upper container can be lifted away from a lower container. However, it may happen that, for some reason, one or several container locks have not been unlocked when the upper container is lifted. As a result, it can happen that two containers are lifted together with each other. This can result in accidents, especially if the container lock is suddenly released in such a situation. It is also a time-consuming and difficult task to open the container locks when the shipping containers are to be unloaded. This can also make the unloading operation dangerous for the personnel responsible for the unloading.
• the container lock comprises a first and a second locking element capable of being joined to respective locking parts on juxtaposed container corners and rotated so as to lockingly engage the container corner.
• the second locking element has a shaft that is translationally mounted in a housing connected to the first locking element such that the shaft can move in the axial direction when the second locking element is pressed against its respective container corner. Between the shaft and the housing, guides are arranged to rotate the shaft when the shaft moves in the axial direction such that axial movement of the shaft causes rotation of the second locking element relative to the housing.
• the shaft has an undercut recess covered by a protuberance. To lock the shaft against rotation, the container lock has a locking arm in the housing.
• the locking arm can be rotated towards and away from the shaft such that the locking arm can be made to engage or disengage the undercut recess when the shaft is in a first angular position and the second locking element is pressed against its respective container comer but that when the shaft is in a second angular position where the second locking element lockingly engages its respective container comer, the protuberance prevents the locking arm from being rotated away from the recess. In this position, the locking arm prevents the shaft from being rotated to an angular position where the second locking element does not engage its respective container comer.
• the first and second locking elements may be lugs and the respective locking parts on the container comers can be shaped with slots into which the lugs can be passed and turned so as to lockingly engage the container comers.
• the first locking element is an upper lug and the second locking element is a lower lug.
• the locking arm is biased towards the shaft by an elastic element in the housing.
• a sensor can be arranged in the housing to detect the position of the locking arm.
• an actuator in the housing is arranged to rotate the locking arm away from the undercut recess when the actuator is activated by an electronic signal.
• the actuator is preferably a shape memory alloy actuator.
• the housing contains a battery providing power for the actuator.
• an elastic element in the housing is arranged to act on the shaft to urge the second locking element axially away from the housing and thereby rotate the second locking element away from the second angular position.
• Figure 1 shows a container lock according to the invention ready for insertion into a slot in an overlying container comer.
• Figures 2 - 4 show fixing of the container lock in the upper container and locking of the container lock in a lower container comer.
• Figure 5 shows in perspective and seen from below a container lock according the invention. It should be noted that Fig. 5 shows an embodiment that is different from the embodiment of Figs. 1 - 4. Figure 6 shows in perspective the same container lock as in Fig. 5 but from a different perspective.
• Figure 7 shows in greater detail a part of the container lock according to the invention.
• Figure 8 shows in greater detail another part of the inventive container lock.
• Figure 9 is a perspective view showing the lower locking lug with the undercut recess and the locking arm.
• Figure 10 is a perspective view showing the lower locking lug from a different perspective.
• Figure 11 is a schematic view from above showing the mechanism for locking the shaft against rotation.
• Figure 12 is a schematic view ftom above where the locking arm has been withdrawn from the undercut recess.
• Figure 13 is a schematic view from above where the locking arm is in contact with the shaft and a part of the undercut recess.
• Figure 14 is a schematic view from above where the locking arm has engaged the undercut recess and is prevented from being rotated away from the recess.
• Figure 15 is a schematic representation of how a container lock is inserted into a lower slot or lock groove.
• Figure 16 shows the container lock of Fig. 15 when inserted and locked.
• Figure 17 is a sectional view through an upper locking lug in insertion position.
• Figure 18 is a sectional view as in Fig. 17 with the locking lug in turned locking position.
• a container lock 1 is shown that comprises a first 2 and a second locking element 3.
• the locking elements 2 and 3 are shown as cone- shaped lugs 2, 3 but the locking elements 2, 3 could also have a different shape.
• the locking elements 2, 3 are connected to a housing 7 that is shown in Fig. 5 as being composed of an upper housing part 8 and a lower housing part 9 that have been connected to each other.
• the first locking part 2 is integral with the upper housing part 8.
• the locking elements 2, 3 are capable of being joined to a respective locking part 4, 5 on juxtaposed containers and rotated so as to lockingly engage the containers.
• the container lock 1 will be joined to container comers but it is conceivable that it could be joined to other parts of the containers.
• the second locking element 3 has a shaft 6.
• the shaft 6 is translationally mounted in the housing 7 that is connected to the first locking element 2 such that the shaft 6 can move in the axial direction into the housing 7 or out of the housing 7. In particular, the shaft 6 will move in the axial direction when the second locking element 3 is pressed against its respective container or container comer.
• the shaft 6 is shaped with curved guide parts 11 and 13. As can be seen in Fig. 9 and Fig.
• the container lock 1 also has corresponding curved guide parts 10 and 12 that can cooperate with the curved guide parts 11 and 13 on the shaft 6.
• the curved guide parts 10 and 12 are located on the housing 7 and are integral with the housing 7.
• the guides or guide parts 10, 11, 12, 13 on the shaft 6 and the housing 7 are arranged to cooperate with each other to rotate the shaft 6 when the shaft 6 moves in the axial direction such that axial movement of the shaft 6 causes rotation of the second locking element 3 relative to the housing 7.
• an upper curved guide 10 on the housing 7 cooperates with an upper curved guide 11 on the shaft 6.
• the upper guide part 11 on the shaft will glide against the curved guide 10 on the housing 7 such that the shaft 6 is forced to rotate.
• the shaft 6 has an undercut recess 14 covered by a protuberance 15.
• the container lock 1 further has a locking arm 16 in the housing 7.
• the locking arm 16 has an articulation 25 such that the locking arm 16 can be rotated towards and away from the shaft 6.
• the locking arm 16 can be made to engage or disengage the undercut recess 14 when the shaft 6 is in a first angular position and the second locking element 3 is pressed against its respective container or container comer as indicated in Fig. 13.
• Fig. 13 In Fig.
• a second angular position of the shaft 6 is illustrated where the second locking element 3 lockingly engages its respective container comer and the protuberance 15 that covers the undercut recess 14 prevents the locking arm 16 from being rotated away from the recess.
• the locking arm 16 prevents the shaft 6 from being rotated to an angular position where the second locking element 3 does not engage its respective container comer.
• An elastic element 22 in the housing 7 can be arranged to act on the shaft 6 to urge the second locking element 3 axially away from the housing 7 and thereby rotate the second locking element 3 away from the second angular position.
• the elastic element 22 is shown as a coil spring 22.
• One end of the coil spring 22 is connected to a part of the shaft 6 and the other end of the coil spring 22 is connected to the housing 7.
• this axial movement of the shaft must be carried out against the force of the coil spring 22.
• the coil spring 22 will seek to force the shaft 6 downwards such that the locking elements 2, 3 are pushed away from each other.
• the first and second locking elements 2, 3 are lugs 2, 3 and the respective locking parts 4, 5 on the container comers are shaped with slots 17, 18 into which the lugs 2, 3 can be passed and turned so as to lockingly engage the container comers.
• the first and second locking elements 2, 3 are shaped as female parts that engage male locking parts on the containers.
• the first locking element 2 would normally be an upper lug 2 and the second locking element 3 a lower lug 3 although it is possible to envisage embodiments where the first locking element would be a lower lug 3.
• the locking arm 16 is biased towards the shaft 6 by an elastic element 19.
• the elastic element 19 can be a coil spring 19 in the housing 7.
• the coil spring 19 is indicated as being located in the lower housing part 9.
• the locking arm 16 is constantly urged against the shaft 6 by the coil spring 19 as indicated in Fig. 9.
• the housing 7 there is an actuator 20 that is arranged to rotate the locking arm 16 away from the undercut recess 14 when the actuator 20 is activated by an electronic signal.
• the actuator 20 is a shape memory alloy actuator 20.
• a shape memory alloy actuator can comprise a set of stacked parallel conductive plates wherein each conductive plate is separated from an adjacent stacked parallel conductive plate with an insulating layer configured to provide electrical isolation between adjacent stacked parallel conductive plates and a low-friction sliding surface between adjacent plates and a set of shape memory alloy links connecting the set of stacked parallel conductive plates.
• the set of shape memory alloy links can generate force to produce sliding displacement along insulating layers between adjacent stacked parallel conductive plates.
• a suitable shape memory alloy actuator is disclosed in US patent No. 6574958 incorporated herein by reference.
• a shape memory alloy actuator suitable for use in the inventive container lock is sold under the name "Nanomuscle actuator" and can be obtained from Nanomuscle Inc. in Antioch, CA, United States of America.
• the housing 7 can advantageously contain a battery 21 providing power for the actuator 20, especially if the actuator 20 is a shape memory alloy actuator.
• a sensor 23 can be arranged in the housing 7 to detect the position of the locking arm 16.
• FIG. 1 the container lock 1 is shown beneath a container part or container comer 4 with a slot 17.
• the container lock 1 will then be moved against the container comer 4 such that an upper locking lug 2 is inserted through the slot 17.
• the upper locking lug 2 is shaped with recesses 27 (see Fig. 5) such that, after insertion through the slot 17, it can be rotated as indicated by the arrow in Fig.2.
• the container lock 1 and the upper locking lug 2 have been rotated, the upper locking lug 2 lockingly engages the container part or container comer 4. It is now impossible to remove the container lock from the container comer 4, unless the container lock 1 is first rotated back again.
• the upper container together with the container lock 1 can then be lowered and placed on a lower container as indicated in
• the lower container has a container part or container comer 5 with a slot 18.
• the lower locking lug 3 will now be inserted through the slot 18 as indicated in Fig.3 and in Fig. 15.
• the lower locking lug 3 and its shaft 6 will now be pressed axially into the housing 7 of the container lock against the force of the spring 22 that is connected to the shaft 6 and the housing 7.
• the guides 10, 11, 12, 13 will cooperate with each other and force the shaft 6 to rotate.
• the lower lug 3 that is integral with the shaft 6 will be rotated as indicated in Fig.
• the lower housing part 9 has a guide part 26 that fits the slot 18 of the container comer 5 of the lower container.
• the guide part 26 cooperates with the slot 18 to prevent the housing 7 from being rotated.
• FIGs. 5 and 6 show an embodiment that differs from the embodiment of Figs. 1 - 4. The difference is the following.
• the upper lug In Figs. 1 - 4, the upper lug
• the lug 2 of Figs. 5 and 6 is a mirror-image of the lug 2 shown in Figs. 1 - 4 since the upper lug shown in Figs. 5 and 6 is shaped in such a way that it will lock to the upper container comer 4 when it is rotated clock-wise. Otherwise, there is no substantial difference between the two embodiments.
• the actuator 20 When the upper container shall be lifted away from the lower container during unloading, the actuator 20 is activated to pull the locking arm 16 away from the shaft 6 against the force of the spring 19. This can only be done when the upper container is still standing on the lower container such that the lower lug 3 is pressed against the lower container as indicated in Fig. 16 and the shaft 6 is in the angular position indicated in Fig. 13. If, for some reason, someone attempts to lift the upper container before the container lock 1 has been removed, the following will happen.
• the normal unloading procedure is as follows. Firstly, a signal is generated that activates the actuator 20.
• the actuator 20 pulls the locking arm 16 away from the shaft 6.
• a signal may be generated that indicates that the upper container can be lifted.
• the lower lug 3 is rotated since the spring 22 will push the shaft 6 downwards as soon as the lower lug 3 is no longer pressed against the lower container comer 5.
• the lower lug 3 can then be passed through the slot 18 in the container comer 5 and the container lock 1 can disengage the lower container.
• the lock 1 is provided with means for counteracting rotation of the upper locking lug 2 when it is locked to the upper container comer 4.
• the upper locking lug 2 may be provided with ball and grove locking pins as indicated in Figs. 17 and 18.
• the upper locking lug 2 there are through bores 29 into that open into the recesses 27.
• Pins 28 are placed in the bores 29 and are held in position in a well known way by a spring-loaded ball-and-groove arrangement.
• the pins 28 have grooves 30 that can receive a ball 31.
• the ball 31 is actuated by a spring 32 and a nut 33 in a way that is known for ball-and-groove locking pins. This kind of locking arrangement is also described in US patent No. 6,334,241.
• the invention confers the advantage that, if an upper container is lifted before the container lock has been removed, the container lock cannot be disconnected while the lower container is still suspended from the upper container.
• An additional advantage is that the sensor will indicate when the lower lug can be disconnected.
• Yet another advantage is that the number of movable parts is small which reduces the risk of malfunctioning. Since all movable parts can be located inside the housing, the risk that salt or ice will disturb the function of the container lock is not so great.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Closures For Containers (AREA)
• Stackable Containers (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (5)

Cited By (8)

Families Citing this family (4)

Citations (4)

• 2003
  • 2003-08-11 SE SE0302200A patent/SE0302200D0/xx unknown
• 2004
  • 2004-07-28 WO PCT/SE2004/001153 patent/WO2005014439A1/en active Application Filing
  • 2004-07-28 DE DE112004001433T patent/DE112004001433T5/de active Pending
  • 2004-07-28 CN CNB2004800298462A patent/CN100484849C/zh not_active Expired - Fee Related
• 2006
  • 2006-01-25 DK DK200600107A patent/DK176701B1/da not_active IP Right Cessation

Patent Citations (4)

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