The present invention relates to a locking device assembly commonly known and hereinafter referred to as a twistlock assembly for mounting into a lifting beam gene¬ rally called a spreader, which is particularly designed to be coupled to load carriers , containers or the like equipped with standardised fittings to facilitate lifting, ^" i.e. fittings incorporating openings to permit releasable coupling to a locking device such as may be fitted to a spreader. It is most important that the lifting and hand- ling of containers is effected quickly and with great operational safety. This demands that the equipment is robustly manufactured and that, despite this, when the lif¬ ting device is damaged or deformed, repairs can ^' be effected with the minimum of delay. All known types of spreaders require tools to- effect the replacement of the twistlocks which enter into and couple with the lifting fittings of the container. These lifting fittings, which are part of the construction of a container, are hereinafter referred to as corner castings. Twistlocks, because of their extended situation, are most prone to damage. When damage occurs, it is important that repairs are effected quickly, other¬ wise great expense may be incurred because a ship may be compelled to wait for loading whilst repairs are beir.g made. Furthermore, in many ports and terminals it is a requirement that any such repairs must be carried out by an authorised mechanic when any such repair demands the use of tools or similar equipment. usually a lifting spreader is releasable coupled to a container by means of corner castings wi-h oval apertures permanently fixed within the container top being coupled to rotatable twistlocks with oval locking heads mounted within the underside of a spreader. Twistlocks, in their open position, can be inserted into the said openings and after being rotated approximately 90 degrees to a locking

position, secure the corner casting to the twistlock. thereb coupling together the container and the spreader. Each twistlock is mounted in a bearing house or support plate and is rotated by an operating device, for example an hydraulic cylinder, which is releasably connected either directly or indirectly to the shaft of the twistlock.

The present invention discloses a construction which enables damaged twistlocks to be replaced without recourse to tools and without -special, knowledge or ability. This means that stevadores or crane operators can themselves effect repairs in a simple way and whereby the above-men- ^' tioned disadvantages can be avoided.

This invention discloses a manually easily mountable and demountable twistlock assembly, the shaft of said twist lock being provided with a groove around its circumference to accept a locking element such as a pair of semi-circular locking rings arranged to bear upon the twistlock bearing house thereby preventing axial displacement with lifting and whereby a casing, arranged to hold the locking rings in place in the twistlock groove, is prevented from axial displacement primarily by the bearing house and its asso¬ ciated elements during working rotation of 90 degrees and yet can be axially released for removal of the twistlock by its being turned past the extent of its normal working area, i.e. past either the twistlock locked or unlocked position.

The invention is below described with reference to the accompanying drawing, showing a selected example of a twistlock in a container spreader, where fig. 1 shows a side view of the device-, fig. 2 shows a section of the device through the line II-II in fig. 1 , fig. 3 shows a pla view of the device, fig. 4 shows a section through an alter native arrangement of the device and fig. 5 shows a section through line V-V in fig. 4. Figs. 6 and 7 in the same way as figs. 4 and 5 show yet a further alternative arrangement of the device.

In fig. 1 the device in its entirety is marked with th figure 1. The twistlock is mounted in a hole through a cor-

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ner of the spreader frame which is here shown in section and is marked 2. Within the hole, and firmly secured to the spreader is a bearing house 3, which rotatably supports a rotatable body 4, shown in more detail in fig. 3, which is turnable by means of force applied to coupling 5.

The rotatable body 4, at its lower extremity and under the bearing house 3, has an oval shaped locking head 6, turnable through approximately 90 degrees by means of coup¬ ling 5. The locking head is ^shaped to coincide with the oval opening of a containers top corner casting so that the-locking head in one position, the unlocked position, can be freely inserted into the opening and thereafter be rotated 90 degrees to a locked position wherewith the ι .. locking head 6 is secured with the container corner casting so that lifting is possible. The locking head 4 can be re¬ tained in either of two different positions.

The _. bearing house 3 shows a top part 7 and an under part 8, which by means of bolts 9 (fig. 2) are mounted on opposing sides of the spreader beam plate 2. Protruding downwards from the under part 8, and' on each side of the twistlock shaft, are guide shoulders 10 and 11, which are so formed to have the same plan shape as the locking head 6 and therefore can be guided into the opening in the con¬ tainer corner casting. Fig. 2 shows are more detailed construction of the associated working parts of the bearing house 3 and the twistlock 4. In fig. 2 is clearly shown the container corner casting 2 and how the bolts 9 bind together parts 7 and 8 which complete the bearing house for the throat 12 of a twistlock shaft 20. This figure also shows the locking head 6 as seen from the short side. The shaft 20 has in its up¬ per part a collar 13 below the end part 14 of the shaft. Into the collar 13 are inserted two half-circle bearing rings 15 and 16 with such a diameter that they extend radial- ly beyond the throat 12 of the shaft 20 and bear against a collar or against the over side of part 7. The bearing rings 15 and 16 are held in position in the groove 13 by a turning element 17, which is pushed over the shaft 20 end part 14.

Between the end part 14 and the turning element 17 is a key 18 arranged for unturnable coupling of the turning ele¬ ment 17 to the end part 14. On the turning element is affixed an arm 19 which is activated through the coupling 5 to position the twistlock body 4 in either of the locked or unlocked positions, which as earlier stated are approxi¬ mately 90 degrees displaced from each other. If desired, the key 18 can be retained in the end part 14 by means of a screw, as shown in fig. 3 , _t To the turning element 17 is affixed a radially pro¬ jecting cam 22 in a segment of not fully ^' 90 degrees. Cam 22 engages with a slot 25 in a tube-shaped house 24 which is immovably affixed to the upper and lower parts 7 and 8. The tube-shaped house 24 contains an axially movable spring loaded catch 26 which in its upper parts supports a rectangular crosspiece 27 ^' arranged to glide against the walls of a radial slot in upper part of the tube-shaped house. The catch 26 and the crosspiece 27 can glide axially in the house" 28 so that crosspiece 27 in one position will axially coincide with the radial cam 22 whilst in another position will be pressed up so high that the cam can pass freely under the crosspiece 27. This arrangement is more clearly described with reference to fig. 3.

Fig. 3 shows a corner casting of a container, which normally has such a corner casting in each of its four upper corners. Fig. 3 also shows the bearing house 3 and twistlock 4 together with some of the details of fig. 1 and fig. 2 earlier described.

In fig. 3 is shown the arm 19 in angular position A, in which the twistlock is in the free position, in other words in that position in which the locking head 6 and shoulders 10 and 11 can be inserted freely into the oval opening in the containers upper corner casting. Coupling 5 can rotate the twistlock anti-clockwise from free posi- tion A to locked position B. In both positions A and B is the twistlock 4 blocked against rotation by catch 26. From fig. 3 it is evident that catch 26 in the shown position prevents the entire twistlock 4 from being rotated anti-

clockwise because the cam 22 goes against the crosspiece 27 in the slot 25 as the catch 26 is in its lowest posi¬ tion so that the crosspiece 27 is in cam 22*s path of movement. When the spreader is lowered and the twistlock assembly rests against the containers corner casting, the catch 26 is impressed and is in the same plane as the under¬ side of the spreader 2.

When catch 26 is pushed upwards, the crosspiece 27 will be lifted above cam 22 's path of movement and coupling 5 can therefore without hinder turn the whole twistlock 4 from position A to position B so that the locking head 6 adopts its working, lifting position. The ^' shoulders 10 and 11 of the bearing house underpart 8 are made to be so long that when the spreader is resting upon the containers corner casting there will be a clearance between the top of the locking head 6 and the lifting contact area within the corner casting. This means that when the spreader is lifted so that the twistlocks make contact within the con¬ tainer corner casting, the catch 26 will move downwards so ^" that the crosspiece 27 once again lies within the movement path of the cam 22 but in this case on the other side of the cam's extremity so that the twistlock is securely re¬ tained in angular position B for lifting.

As indicated above, there exists a list of regulations governing the security of lifting equipment for containers, and twistlocks shall have a wide margin of safety. In spite of its complicated function, the twistlock device according to the present invention is very simple to assemble and disassemble. To replace a twistlock shaft, which is that part most prone to damage or deformation so that the locking device does not function, is particularly easy. The replacement of a twistlock is effected in the following way, in which the use of tools in any shape or form is not required. As described above, twistlock 20 is held in its axial position by means of the bearing rings 15 and 16 in the groove 13 being secured radially by tur¬ ning element 17. The turning element 17 is held in its axial position through the combination of the radial cam

22 with the slot 25 in housing 24. From fig. 3 it is obvious that cam 22 in its end position, which can be de¬ termined by the. end positions of coupling 5, with its oute end in contact with slot 25 is prevented from moving up- wards, whereby turning element 17 holds together parts 20, 15, 16, 22, 18 and 19 and holds them in place.

With disassembly, the operating rod of coupling 5 is manually removed from the arm 19 to which it is attached by ball-joint. The turning ^element 4 is thereby free to be rotated a further few degrees clockwise so that the cam's 22 outer corner is clear of the corner 29 of the tubeshape housing 24. Thereafter can turning element 17 with arm 19, key 18, and screw 21 be lifted straight upwards and laid to one side. Both bearing rings 15 and 16 can then be re- moved radially outwards and finally twistlock 20 can be drawn free downwards and away from bearing house 3 and the spreader.

A new twistlock 20 can be assembled in the same easy way without tools by being pushed into bearing ^' house 3 so far that bearing rings 15 and 16 can be replaced in groove 13. The turning element 17 is then pushed down over the end part 14 and the bearing rings 15 and 16 so that these will be locked into the groove 13. Finally the turni element 17 is rotated so that the ball-joint on arm 19 re- turns to that position where coupling 5 can be replaced whereby the whole assembly is once again ready for use through the cam 22 being turned so that it once again unit under the corner 29 in the tube-shaped house 24.

Fig. 4 shows the upper section of an alternative arrangement in section and the same markings are used as in the earlier figures. This figure discloses an alternati arrangement which prevents turning element 17 within the working area A-B from gliding axially upwards so that the bearing rings 15 and 16 can come out of position. In the arrangement according to fig. 4, the key 18 is fastened to the turning element 17 with a screw 21. When the arm 19 is rotated from A to B, the key 18 is also turned from A to B, as in fig. 3. When the turning element 17 is axially

moved, the key 18 glides in a slot 23 in the end part 14. Concentric with the end part 14 is a stud 30 with the same diameter as the end part 14 and with a length which per¬ mits turning element 17 to glide upwards until its under- 5 side rises above the upper edge of bearing rings 15 and 16. The stud 30 is affixed to a bearing plate 31 which is in¬ directly united with the bearing house's upper part 7. Stud 30 has a keyway 32 which has such dimensions that the key 18 can be pushed into the keyway when the end part

10 14 is at such an angle that slot 23 and keyway 32 are opposite each other.

In the right half of fig. 4 is shown how. the turning element 17 is pushed upwards away from its bearing rings 15, 16 axial securing position be key 18 being entered

15 into keyway 32. The left half of the figure shows that position where the turning element 17 has reached its end position against bearing plate 31. In this position the bearing rings 15, 16 are no longer secured radially, but can be drawn out from groove 13 as is shown for bearing

20. ring 16 in the diagram. When both bearing rings 15, 16 have been withdrawn, twistlock 20 can be removed down¬ wards and demounted from the assembly. Re-assembly with a new twistlock is effected in the reverse order and bearing rings 15, 16 are secured by turning element 17

25 being pushed downwards after the twistlock has been posi¬ tioned so that slot 23 is opposite keyway 32. The turning element's locking collar 34 then lies outside and around bearing rings 15, 16 thereby preventing these from moving radially outwards.

30 Fig. 5 shows a section through line V-V in fig. 4. This diagram shows that stud 30 has two keyways 32 and 33 for acceptance of key 18. In yhis diagram are also shown the end positions A and B for the key 18 ' s rota¬ tion within the working area A-B. As can be seen, key-

35 ways 32 and 33 lie outside this working area. If turning element 17 is rotated so that key 18 lies in the middle of keyway 33 then turning element 17 can be lifted in the same way as described above. Keyway 33 can be placed

- in such a position where it would be easiest to manually effect demounting of bearing rings 15 and 16. To ensure that turning element 17 shall remain in its axially lower locking position, keyways 32 and 33 shall not lie within the working area A-B otherwise the key may unwillingly glide up into the groove and the bearing rings 15 and 16 ^' come loose. Keyways 32 and '33 can otherwise be placed in any desired position outside this working area.

Figures 6 and 7 show y§t another possible example of the invention, where for the same parts the same indi¬ cation figures have been used. Bearing rings 35 and 36 extend further in a direction in which holes 37, 38 are arranged to unite with studs 39, 40 within a turning ele¬ ment 41 united with an arm 19. Studs 39, 40 prevent bea- ring rings 35, 36 from gliding out from groove 13. The turning element has a central rectangular recess which unites with the rectangular part 46 of the throat part 12 in order to rotate the locking part 6.

The turning element rotates between positions A and B, see fig. 1 -. Above the turning element's flange 47 and united with upper part 7 are two tongues 44, 45. The flange shows two recesses 42, 43 which normally move between the tongues 44, 45. If the operating part is re¬ moved from the arm 19, the turning element 41 rotates so that recesses 42, 43 coincide with tongues 44, .45 and can be lifted axially upwards. Studs 39, 40 are pulled out from the holes 37, 38, and the bearing rings 35, 36 and twistlock 20 can be dismantled and reassembled as described previously. The described constructions and diagrams are examples given only to explain the purpose and background of the invention, ^' and one skilled in the art could achieve many other constructions which would fall within the bounds of the following patent claims.