Patent Publication Number: US-6334241-B1

Title: Container lock

Description:
The invention relates to a container lock including an upper and a lower locking lug capable of being passed into a respective lock groove in juxtaposed container corners and turned so as to lock therein in that the lower locking lug is pivotally and translationally mounted in a housing connected to the upper locking lug by means of a shaft capable of limited movement in the axial direction, which shaft is lock-actuated by a spring in the housing in a downward direction, and between the housing and the shaft there are arranged guide means which permit a locking rotation of the lower locking lug on upward movement of the shaft. 
     DE 195 34 767 A1 makes known a container lock having two mutually rotatable lugs. These lugs are capable of moving vertically relative to one another. When two containers are brought together, the lugs are released. They are under spring tension and pivot into engagement or locking position. This locking position can be released by means of a handle mechanism. 
     DK 157987 B makes known a container lock having a lower locking lug which is pivotally mounted in a housing connected to the upper locking lug. Spring pre-tensioning is used for the lower locking lug. 
     According to the invention, there is proposed a container lock as mentioned above, characterised in that the lower locking lug is designed to have a pressure ball intended for abutting interaction with a bottom of a lock groove when an upper container is placed on a lower container, so that the housing is thus pressed down over the shaft, thereby forming a gap between a downward facing circumferential annular surface on the shaft and the lower part of the housing, and in that in the housing there is arranged a locking device, including spring-actuated locking arms which will move in towards the shaft to a position in the gap below the circumferential annular surface and thus as a spacer prevent the return axial movement of the shaft. 
     A container lock of this kind can by means of its upper locking lug be passed into a lock groove in a subjacent container corner and turned so as to lock therein. A container lock of this kind is arranged in each corner of the container. The container can then be brought into position over another container by means of suitable lifting tackle and lowered down thereon so that the respective lower locking lugs pass into the upward facing lock grooves in the upper container corners of the lower container. The spherical end faces of the lower locking lugs will come to rest against the bottom of the respective upward facing lock grooves. Thus, the lower locking lug and associated shaft will be displaced upwards in the housing, with simultaneous locking rotation as a consequence of the said guiding means between the housing and the shaft. 
     The two containers will now be locked together and the lower container can thus be lifted together with the upper container. 
     The unlocking force will be very small, almost zero, because the supporting arms can swing relatively freely out of and into the gap which will be formed between the head of the shaft and a lower face in the housing when the vessel, for example, is in dock, but is almost impossible to open when the vessel heels at speed on the open sea. 
     Instead of the upper container, there may be used a lifting yoke having four so-called container corners wherein the container locks can be inserted. 
     It is particularly advantageous if the locking arms of the locking device include a hinged pair of claws designed to have interacting swivel toothing and which grip about the shaft. 
     Furthermore, it would be advantageous to provide a spring-actuated operating member for the locking arms. 
     The operating member of the locking device and tension spring may to advantage be arranged in a radially projecting part of the housing. 
     Advantageously, the spring for tension-actuation of the shaft may also be a spring which acts against the free end of the shaft. 
     The said guide means can advantageously include a helical guide groove on the shaft and a guide pin fixedly arranged radially in the housing and which runs in the guide groove. 
     In the upper locking lug or housing there may advantageously be provided ball-and-groove locking pins intended for interaction with walls in a lock groove. 
     The shaft may to advantage be a screw bolt which is screwed into the lower locking lug. 
     It is especially advantageous if the housing is sealed off from the outside and filled with oil or the like. 
     The said operating member can according to the invention advantageously be drive-connected to an electromagnet. 
    
    
     The invention will now be explained in more detail with reference to the drawings, wherein: 
     FIG. 1 is an exploded view of a container lock according to the invention; 
     FIG. 2 shows a container lock according to the invention ready for insertion into a lock groove in an overlying corner; and 
     FIGS. 3-7 show fixing of the container lock in the upper container corner and locking of the container lock in a subjacent container corner; 
     FIG. 8 is a sectional view through the container lock, with the lower locking lug in insertion position; 
     FIG. 9 is a sectional view through the container lock as in FIG. 8, but with the lower locking lug in a locking position; 
     FIG. 10 is a perspective view of the container lock in the locking position shown in FIG. 9; 
     FIG. 11 is a longitudinal section of the container lock during insertion into a lower lock groove; 
     FIG. 12 shows the container lock in FIG. 11 when inserted and locked; 
     FIG. 13 is a longitudinal section through the container lock, taken at 90° to the longitudinal section in FIG. 11; 
     FIG. 14 is a sectional view of the container lock as in FIG. 13, but in the inserted and locked position; 
     FIG. 15 is a sectional view through an upper locking lug in insertion position; 
     FIG. 16 is a sectional view as in FIG. 15, with the locking lug in turned locking position; 
     FIG. 17 is a longitudinal section of an especially advantageous embodiment of the invention; and 
     FIG. 18 is a sectional view through the embodiment in FIG. 17, taken in the dividing plane between the two housing halves. 
    
    
     FIG. 1 shows in exploded view the individual components of a container lock according to the invention. The assembled components are shown in FIGS. 8,  9  and  11 - 14 . 
     A cup-shaped housing  21  has an upward facing mouth having an internal threaded portion  20 . In the bottom of the housing  21  there is a through bore  22 . A lower locking lug is indicated by means of the reference numeral  24 . This lower locking lug has a threaded blind hole  23 , intended for screw-interaction with a threaded portion  15  on a bolt  14 . The bolt  14  and the locking lug  24  are screwed together in that the bolt  14  is passed down through the bottom bore  22  in the housing  21  and screwed into the threaded bore  23  in the locking lug  24 . A pin  61  secures the connection. In the lower end thereof, the locking lug  24  has a thrust ball  25  that has been rolled into place. 
     An upper locking lug  1  is made integrally with a part  5  which has an external threaded portion  7  intended for screw-interaction with the internal threaded portion  20  in the housing  21 . The upper locking lug  1  has two diametrically opposite oblique notches  40  (only one is shown). 
     The bolt  14  acts as a shaft for the lower locking lug  24  in the housing  21  and has a head  12  with two diametrically opposite helical grooves  13  (only one is shown) on the circumferential surface of the head. When the container lock is assembled, these guide grooves  13  will enter engaging interaction with guide pins  8  which run in radially extending bores  42  in the cover part  5 . On its underside, the cover part  5  has a depression for receiving the head  12  of the bolt  14 , so that the guide pins  8 , when pushed in, will enter the respective guide groove  13 . 
     The head  12  of the shaft  14  has a blind bore  11  for receiving an abutment part  10  which forms centring abutment for a coil spring  9 . The upper end of the coil spring goes against the bottom surface of the said bottom depression in the cover part  5 . When the container lock is assembled, the spring  9  will thus be squeezed between the cover part  5  and the head  12  of the shaft or bolt  14  and tension-actuate the shaft  14 , and thus also the lower locking lug  24  screwed together therewith, in a downward direction. 
     In the housing  21  and in a radially projecting part  26  there is arranged a locking device for the shaft  14 . This locking device includes a pair of claws  16 ,  17  which are pivotally mounted in the housing  21  by means of pivot pins  19 , which run in bores  18  in respective claws  16 ,  17 . The claws  16 ,  17  have interacting toothing  43 , and one of the claws  16  has an extended portion with a bore  39  for receiving a pin on a forked member  38 , the other pin of which runs in a bore  37  in a rod portion  29 . This rod portion  29  has a blind bore for receiving a spring  31 . The rod portion  29  is a part of a telescopic operating rod, the other end of which is formed by a rod portion  32 . This rod portion  32  also has a blind bore for receiving the spring  31 . The two rod portions  29 ,  32  are brought together with inserted spring  31  so that the outer portion  32  will grip around the collar  30  on the portion  29 . By means of rolling or suitable compression, the rod portion  32  can be brought into engagement behind the collar  30 , so that the two rod portions  29 ,  32  will be capable of limited axial displacement relative to one another, with the spring  31  fixed therebetween. 
     A U-shaped member  35  is secured at the two ends thereof to a respective cylindrical body  34 . The two cylindrical bodies  34  have a respective eccentric bore for receiving a cross bar  36 . In the outer rod portion  32 , there is a transverse groove  33  for receiving and interacting with the eccentrically positioned cross bar  36 . The cylindrical bodies  34  are designed for insertion in recessed portions  37  at the end of the housing part  26 . The housing part  26  has a radial through passage  28 , which thus extends from outside the housing  26  and opens into the interior of the actual housing  21 . 
     The container lock shown in an exploded view in FIG. 1 is assembled in the following way: 
     The rod portions  29 ,  32  are put together with the spring  31  and the rod portion  32  is rolled in the end, on the rear of the collar  30 , thus producing a telescopic rod. This is inserted into the passage  28  so that the bore  37  in the rod portion  39  is accessible inside the housing  21 . The pair of claws  16 ,  17  are put in together with the pivot pins  19 , and the forked member  38  is put in place in the respective bores  37 ,  39 , so that the rod portions  29 ,  32  which form the operating rod are coupled to the pair of claws  16 ,  17 . In this connection, reference is also made to FIGS. 8,  9 ,  11 - 14 . The bolt  14  is put together with the spring  9  and the cover part  5  and thus with the upper locking lug  1 , the guide pins  8  being passed into the respective bore  42  and into engaging interaction with a respective guide groove  13  on the bolt head  12 . The assembly thus obtained is then connected to the lower locking lug  24  in that the bolt  14  is passed down through the bore  22  in the housing  21  and screwed together with the lower locking lug  24 . The cover part  5  is screwed by means of its threaded portion  7  into the threaded portion  20  in the housing  21 . The telescopic operating rod  29 ,  32  is coupled to the U-shaped member  35  in that the eccentric cross bar  36  is taken out, the cylindrical bodies  34  are placed inside the respective receiving members  27  and the cross pin  36  is then put in place, with engagement in the cross groove  33 . 
     The use and the mode of operation of the new container lock will now be described in more detail, with particular reference to FIGS. 2-7. 
     The container lock shown in FIG. 2, where the main components  1 ,  21  and  24  are indicated, is ready for connection with a superposed container corner  50  which has a downward facing lock groove  51 . The U-shaped member  35  has been swung down, which means that the eccentric mechanism  33 ,  36  does not pre-tension the spring  31 . The container lock is passed into the lock groove  51 , as shown in FIG. 3, and is turned as shown in FIG.  4 . The U-shaped member  35  is swung up as shown in FIG. 4, whereby the spring  31  (FIG. 1) is pre-tensioned, the portions  32  and  39  being pressed together by means of the eccentric mechanism  36 ,  33 . The claws  16 ,  17  bear against the head  12 , see FIG. 8, and will now be pre-tensioned relative to the shaft head  12 . The upper locking lug  1  is now brought into locking interaction with the container corner  50 . The lower locking lug  24  will be positioned and ready for insertion into a subjacent container corner  52 , as shown in FIG.  5 . When the container lock is lowered into the lock groove  53  in the container corner  52 , the ball  25  on the lower locking lug  24  will move towards a bottom abutment (FIGS. 12,  14 ). Thus, the lower locking lug  24  and its shaft  14  are pressed upwards, with simultaneous rotation of the shaft  14  and the locking lug  24 , as a consequence of the interaction between the oblique guide grooves  13  and the guide pins  8 . This is shown in FIG.  6 . FIG. 7 shows the two container corners  50 ,  52  locked together by means of the container lock. 
     The shaft or bolt  14  is pushed up against the action of the spring  9  so that the two claws  16 ,  17  have now snapped into place under the head  12  of the bolt  14 , as is shown in FIG.  9 . The claws  16 ,  17  snap into place under the action of the pre-tensioned spring  31  which is in the telescopic operating rod  29 ,  32 . This locking of the head  12  of the bolt  14  means that the lower locking lug  24  cannot move downwards, despite it being urged in a downward direction by the tension spring  9 . The lock connection in FIG. 7 will therefore be secured. 
     The upper locking lug  1  is secured by means of ball and groove locking pins  6 , see FIGS. 1,  2 ,  4 ,  15  and  16 . In the upper locking lug  1  there are two through bores  41  which open into each of the respective recesses  40  and initially are in a position where they extend into the respective recesses, as shown in FIG.  2 . The pins  6  are retained in this position by means of a respective ball  2  which runs in a cross bore and is actuated by a spring  3  and a nut  4 , in a well known way for ball-and-groove locking pins. In this position, the ball  2  interacts with one of the two circumferential grooves on the respective pin  6 . 
     When the upper locking lug  1  is passed into the lock groove  51  and turned as shown in FIG. 4, the two pins  6  will run against their respective walls in the lock groove  51  and be displaced as shown by the arrows in FIG. 4 to a position in which the respective detent ball  2  has a locking interaction with the other of the two circumferential grooves on each of the pins  6 . This means that the upper locking lug  1  will be locked with a certain resistance in the rotational locking position shown in FIG. 4 (see also FIGS.  15  and  16 ). 
     When the lock in FIG. 7 is to be released, the U-shaped member  35  is swung down to a position as shown, for example, in FIG.  2 . The spring  30  is thus relieved of tension and the operating rod is pulled out so that the claws  16 ,  17  are spread and release the head  12  of the bolt  14 . The spring  9  will now press the bolt  14  and the lower locking lug  24  downwards. The container lock can now be turned and released from the upper lock groove  51 . Subsequently, the container lock can be removed from the lower container corner  52 . 
     The design of the container lock is such that it can be opened and closed by the U-shaped member  35  when the container lock is in place between two juxtaposed container corners because the pair of claws  16 ,  17  will not be loaded by the head  12 , see FIG.  14 . It is only by lifting (the ball  25  is lifted from the bottom abutment) that the spring  9  will press the head  12  downwards into abutment against the subjacent pair of claws  16 ,  17  and cause the operating mechanism to be friction-locked. 
     Advantageously, the container lock may be equipped with inserted O-rings  55 ,  56  and  58 . These O-rings will define a sealed chamber wherein advantageously oil or the like may be introduced to prevent water penetration and condensation. In order to prevent particles from penetrating into the container lock, and also to make the container retentive of any internal liquid filling in order thereby to prevent corrosion, an O-ring  56  is placed in a 45° chamfer  57  in the outlet of the threaded portion  20  on the housing  21 . When the locking lug  1  and the housing  21  are screwed together, there is thus a leakproof connection. 
     Similarly, an O-ring  55  is fitted in a groove  62  at the bottom in the through bore  22  in the bottom of the housing  21 . The O-ring seals against the screw  14 . 
     Likewise, an O-ring  58  is fitted in a groove  57  on the outer rod portion  32 . This O-ring seals against the radial through passage  28  in the housing part  26 . 
     FIGS. 17 and 18 show another especially preferred embodiment of a container lock according to the invention. 
     This container lock has two juxtaposed housing halves, an upper housing half  70  and a lower housing half  71 . The two housing halves  70 ,  71  are screwed together with screws  72 . 
     An upper locking lug  73  is integrally formed with the upper housing half  70 . As shown in FIG. 17, there is cut out in the upper housing half  70  a stepped blind bore  74 ,  75  for receiving respectively the head  76  of the shaft  77  and a compression spring  78  which presses against the head  76  of the shaft. 
     The shaft  77  is rotatably mounted in a through bore  79  in the lower housing half  71  and supports a lower locking lug  80 . The locking lug  80  has a thrust ball  81  intended for abutment against the bottom of the lock groove, not illustrated in this case, in a container corner. In this embodiment too, a locking device is arranged in the housing for the shaft  76 ,  77 . Here, the locking device is also in the form of a pair of claws  82 ,  83  which are pivotally mounted in the housing  70 ,  71  by means of pivot pins  84  and  85 . The claws  82 ,  83  have interacting toothing  86 ,  87  and one of the claws  82  has a bore for a pin  88  which connects the claw  82  with a piston  89 . 
     The piston  89  is slidably arranged in a sleeve  90  and is actuated by a tension spring  91  in the sleeve. The tension spring  91  acts to swing the claws  82 ,  83  from the free position shown in FIG. 18 to a locking position under the head  76  of the shaft, as shown in FIG.  17 . An electromagnet  92 , when supplied with power, draws the piston  89  inside the sleeve  90 , against the action of the spring  91 . The pair of claws  82 ,  83  is thus opened and releases the shaft  76 ,  77 . The spring  78  will then move the shaft  76 ,  77  in a downward direction. 
     As in the first embodiment, there is provided a guiding system  93  (corresponding to  8 ,  13  in the previous example). 
     It will be appreciated that the embodiment shown in FIGS. 17 and 18 functions on the same principles as explained in connection with the embodiment in FIGS. 1-16. 
     Special mention should be made of the fact that loading will cause a gap to be formed between the bottom of the housing  21  and the head  12  of the shaft  14  and between the head  76  and the subjacent annular surface in the lower housing part  71 , so that the two claws  16 ,  17  and  82 ,  83 , respectively can pivot relatively freely, without greater resistance than that yielded by the springs  31  and  91 , respectively (about 1 kilo). The two claws  16 ,  17 ;  82 ,  83  will move to the locking position without appreciable resistance. The two locking lugs will be rigidly interconnected, and will form a unit, which almost without the exertion of force can be separated when, e.g., a vessel moors in a dock, but which in the event of a storm will resist great forces. 
     The two housing halves  70  and  71  together form a chamber  95  which is fluid-filled, i.e., filled with cold-resistant oil, so that icing is prevented and contaminants cannot prevent the locking function.