Lashing Fitting

Abstract

Lashing fittings are characterized in that the rotation of the twistlock is automatically activated by vertical compression caused by the weight of a container coming into contact with the housing of the lashing fitting attached to a container or a loading platform, said twistlock being rotated by means of a force which is released exclusively by the said act of the weight of a container reacting against the housing of the lashing fitting thereby transmitting to the twistlock a revolving movement towards a locking position within said corner casting. An indicator is provided for indicating the tripping of the lashing fitting for connecting the containers in question to the lashing fitting and thereby to one another, and, on the other hand, angular displacement in opposite directions of the arrow tip-like heads of the twistlocks of one lashing fitting in relation to each other and, further, a sub-division of the revolving movement of the lock members over an angular range of 180.degree. into two unequal steps during turning of the twistlocks to respectively the locked and the released positions.

Description

The invention broadly refers to a device for securing a freight container to a loading platform and/or to another container within a stack of a multiplicity of such freight containers. In the following description, the device is referred to as a lashing fitting and the practice of assembling containers together into a stack or block is referred to as lashing. Most specifically the invention refers to a new type of lashing fitting in the form of a self-contained removable unit adapted to be attached to corner castings in containers and/or to load decks to cause a container to become interconnected with another container or to a loading deck by engagement with the lashing fitting.

Prior art lashing equipment for lashing containers comprise wires, chains or the like binding together the various containers to form coherent structures or stacks upon a loading platform such as the deck of a ship. This prior art procedure has been time consuming and hazardous due to the fact that the stevedores had to climb up and down the container stack in order to place or remove the many various lashing fittings. The prior art also comprises a variety of lashing fittings which depending on the place of use, such as between the deck and the lowermost container, between pairs of stacked containers or on top of the containers, have been of many different types. Accordingly, loading time has been extended due to the time consuming and troublesome lashing of the containers and the necessity to select suitable lashing fittings for use in the various positions. As port time is an important cost factor, loading and unloading must be performed with the least possible delay and for this reason containers of standard type (ISO standard) have been adopted to an increasing extent, such standard containers being available in several sizes but having identical corner castings or corner fittings with mutually corresponding apertures. Frequently, the loading decks are provided with apertures corresponding to the apertures of the corner boxes. However, prior art types of lashing devices do not permit containers of different height to be accommodated in the same block because the lateral lashing fittings require a disposition of containers of identical height adjacent each other. All these conditions as well as the above mentioned risk of accidents in connection with manual lashing operations have contributed towards creating in this field of transport a need for the automatic or semi-automatic lashing of containers, preferably a means to permit automatic lashing of containers irrespective of height and lateral interrelation between stacks within the same block.

All the above mentioned drawbacks of prior art devices and procedures for lashing containers mutually and in relation to loading decks can be substantially eliminated in accordance with the present invention which also complies with the above mentioned need for arrangements for automatic lashing of containers irrespective of height, this favorable result being obtained, in accordance with the invention, in a lashing fitting for releasable lashing of freight containers mutually and/or in relation to a loading platform, such lashing fitting being a separate unit comprising a housing and, extending therefrom, at least one rotatable lock member, hereinafter called a twistlock, which in an initial position can be introduced into the elongate aperture of a corner casting of a container. According to the invention these lashing fittings are characterized in that the rotation of the twistlock is automatically activated by vertical compression caused by the weight of a container coming into contact with the housing of the lashing fitting attached to a container or a loading platform, said twistlock being rotated by means of a force which is released exclusively by the said act of the weight of a container reacting against the housing of the lashing fitting thereby transmitting to the twistlock a revolving movement towards a locking position within said corner casting.

The usefulness of the basic lashing fitting is further enhanced by certain modifications comprising, on the one hand, the provision of an indicator for indicating the tripping of the lashing fitting for connecting the containers in question to the lashing fitting and thereby to one another, and, on the other hand, angular displacement in opposite directions of the arrow tip-like heads of the twistlocks of one lashing fitting in relation to each other and, further, a subdivision of the revolving movement of the lock members over an angular range of 180.degree. into two unequal steps during turning of the twistlocks to respectively the locked and the released positions.

By way of example some embodiments of the invention will be described in detail in the following description by reference to the attached drawings in which mutually corresponding parts have the same reference designations and in which

FIG. 1 is a perspective view showing several containers during loading or unloading of one container C,

FIG. 2 is a vertical sectional view of a lashing fitting according to the invention,

FIG. 3 is a horizontal sectional view of the lashing fitting along line III--III in FIG. 2,

FIG. 4 is a vertical sectional view of a lashing fitting as being inserted into two opposed corner castings of two superimposed containers,

FIG. 5 is a vertical section of a part of the lashing fitting provided with a protruding bottom plate for attachment in relation to guide rails on a ship deck or similar platform,

FIG. 6 is a side view of another embodiment of the lashing fitting according to the invention provided with disengaging means, portion of the lower part of the housing being broken away to uncover certain inner structural parts,

FIG. 7 illustrates the lashing fitting shown in FIG. 6 turned 90.degree. from the position shown in FIG. 6,

FIG. 8 is a sectional view along line VIII--VIII in FIG. 7 of the device illustrated in FIGS. 6 and 7,

FIG. 9 is a view similar to FIG. 6 illustrating another embodiment of the lashing fitting according to the invention, and

FIG. 10 is a view similar to FIG. 7 of the modified embodiment according to FIG. 9.

Referring to FIG. 1 there is shown a freight container C being lowered onto a stack of similar containers. All the containers are provided with corner castings 11, 12. As appears from FIG. 1 lashing fittings 1 according to the invention are attached to the upper container C to enable this container to be coupled to the lowermost forward container within the stack by simply lowering the upper container C onto the underlying container. As appears from FIG. 1 containers of varying length may be placed adjacent to each other, it also being obvious that containers of different height can be stacked together whereby the need inherent in prior art systems for a time-consuming assembly of mutually corresponding containers is eliminated.

Referring to FIGS. 2 and 3 there is shown in detail how the lashing fitting according to the invention is constructed. A housing is formed by assembling U-beam sections 1a and 1b with the shank ends in mutual contact and united by welding along the lines of contact. Reinforcing struts are welded both to the united shanks of the U-beam sections and to each other as shown at 1c. A handle 19 is provided at one side of the box-like housing so formed. A central shaft 3 extends through said housing 1, both ends of said shaft being shaped as arrow-tips forming heads 2, 13 on either side of housing 1. For reasons explained further down either or both of said heads 2, 13 is provided with a through bore 20. A pin 5 or similar part extends from shaft 3 within housing 1 to anchor one end of a torsion spring 4 to shaft 3. The opposite end of torsion spring 4 is attached to housing 1, for example, as shown in FIGS. 2 and 3 at said reinforcing struts extending between the shank portions of the U-beam sections. A locking pin 6 is also rigidly mounted on shaft 3 to restrict in a way as described further down the revolving movement of shaft 3. Between the surface of either head 2, 13 facing housing 1 and the housing itself there are provided guides or filling pieces 18, said guides being firmly attached to housing 1 and enclosing shaft 3. A tripping stud 7 extends from the interior of housing 1 through one of the housing walls adjacent shaft 3. A tripper piece 15 is mounted onto the shaft of release stud 7 inside a recess 16 in the wall of housing 1. For reasons explained further down a recess 8 is provided on the side of the shaft of release stud 7 facing shaft 3. The lashing fitting is held in position by insertion of guide or filling piece 18 into the elongate aperture of the corresponding corner casting, said guide or filling piece having a corresponding cross sectional shape substantially filling said aperture. An abutment piece 17 is arranged within housing 1 diametrically opposite said tripping stud 7 in relation to shaft 3. Torsion spring 4 is shown to enclose and extend around shaft 3.

The lashing fitting as illustrated in FIGS. 2 to 4 operates as follows. Lashing fittings according to the invention are placed into the four upper corner castings of a container after a tool has been inserted through bore 20 of the upper arrow tip head 2 to turn shaft 3 and its heads 2 and 13 a half turn or 180.degree. in a direction for tensioning spring 4. During the priming of the lashing fitting, locking pin 6 passes through recess 8 of tripping stud 7 and against vertical spring tension (not shown) which presses tripping stud 7 upwards so that after locking pin 6 has passed through recess 8, the shaft of tripping stud 7 will provide a stop against locking pin 6 being returned through recess 8. Now the lashing fitting is conditioned for the subsequent automatic lashing or coupling operation.

When a container is lowered upon four tensioned lashing fittings of the type illustrated in FIGS. 2 to 4, the protruding upper arrow tip head 2 of the lashing device will enter into the lower corner casting of the container being lowered in a way as illustrated in FIG. 4. When the container is lowered onto the lashing fitting the lower face of the corner casting will depress tripping stud 7 whereby the recess 8 of tripping stud 7 will be aligned with locking pin 6 which previously in the primed state of the fitting had been retained by a side surface of tripping stud 7, as appears from FIGS. 2 and 3, but which now is permitted to pass through recess 8 under the turning action of torsion spring 4. This enables shaft 3 with its arrow tip heads 2, 13 to rotate through 90.degree. until pin 5 which is engaged by torsion spring 4 abuts against the side face of tripping stud 7. In this position the revolving movement of shaft 3 will thus be stopped and the arrow tip heads 2, 13 will be stopped in a position at a right-angle to the starting position, these heads thus extending transversely across the inner surfaces of the corner castings, thus providing a locking action enabling the lashing fitting according to the invention to couple or interconnect the two containers.

When the cargo has arrived at the place of destination and the containers are to be removed they are released from the lashing fittings and thereby from each other in the following way: The tripper piece 15 is actuated manually or with the aid of a tool through recess 16 in the side wall of housing 1 in a downward direction as seen in FIGS. 2 and 4 whereby pin 5 is permitted under the pressure of spring 4 to pass through recess 8 in the tripping stud 7. Now the accumulated turning force of torsion spring 4 will cause shaft 3 with its arrow tip heads 2, 13 to turn through an additional range of 90.degree. until locking pin 6 will abut against abutment piece 17, as will appear from FIG. 3. In this position the arrow tip-like heads 2, 13 of shaft 3 will once again be aligned with the elongate aperture 14 in the corner castings 11, 12 of the containers, heads 2, 13 thus having completed a total revolving movement through half a turn, so that the upper container may be lifted off from the lashing fittings unrestricted by the lashing fittings which remain seated in the lower container.

A modified embodiment of the invention is shown in FIG. 5 showing a lashing fitting adapted to be inserted into stationary guide rails 10 or similar devices on a loading platform such as the deck of a ship to enable a lowermost container to be lashed on board. For this reason the lashing fitting is provided with only one lock member 2 extending from housing 1 whereas the opposite side of the house is provided with a locking plate 9, locking stud, locking flange or the like extending from the housing in an outward direction. Thus, the lashing fitting can be inserted by a lateral shifting movement into engagement with stationary guide rails 10 on the loading platform, whereafter the upper arrow tip head 2 of the shaft 3 is tensioned by a revolving movement extending over half a turn thus conditioning the lashing fitting to perform the action described in connection with the first embodiment when a container is lowered onto the primed lashing fittings.

In FIGS. 6 to 8 there is shown a modified embodiment of the invention so constructed that lashing fittings may be suspended from the bottom face of a container by insertion into the downward facing corner castings thereof. This result is obtained by angularly displacing the vertical alignment of arrow tip head 13 on shaft 3 in relation to the filling piece 18 while arrow tip head 2 remains in alignment with filling piece 18. The angular displacement between arrow tip head 13 and filling piece 18 amounts to between 10.degree. and 170.degree., a displacement of about 30.degree. being preferred, but this is obviously dependent upon the size and shape of the aperture. By thus permitting suspension of the lashing fitting from the bottom surface of a lifted container as shown in FIG. 1 stevedores need no longer perform the hazardous work of climbing upon already stacked containers to place lashing fittings in to the four upper corner castings. If a lashing fitting according to this embodiment is to be suspended from the bottom of a container the lashing fitting is up-ended, and upper lock member 13 of the lashing fitting -- shown in the drawing as the lower lock member -- is stressed against tension of spring 4 to a position aligned with the elongate guide 18 thus permitting the arrow tip head 13 together with the guide 18 to be inserted into the elongate aperture in the corner casting of the container. With the arrow tip head inserted into the corner casting torsion spring 4 will turn back the head of lock member 13 to its initial position in which the lock member is angularly displaced in relation to the elongate aperture of the corner casting whereby the lashing fitting will be securely suspended from the lower surface of the container. In the primed state of the lashing fitting, locking members 2, 13 together with shaft 3 have been rotated against tension of spring 4 through 180.degree. and the return rotation of shaft 3 resulting from the said tension of spring 4 is prevented only by the abutment of locking pin 6 against a stopping piece 32 which is affixed to stud 7. Upon suspending the lashing fitting from a bottom corner casting of a container, the filling piece 18 will substantially fill the elongate aperture of corner casting while locking member 13 will be unrestricted within the corner casting to re-adopt its angular disposition from filling piece 18 and thereby preventing the lashing fitting from falling free from the corner casting. Locking member 2, remaining in alignment with filling piece 18 will thereby be unhindered from entering into its appropriate location, and upon making contact with the surface of the lashing fitting's location, release stud 7 will be depressed sufficiently to allow locking pin 6 to pass by locking stop 32 during rotation of shaft 3 under pressure from spring 4. Rotation of shaft 3 is then stopped by the coming into contact of pin 5 with locking stop 32 thus restraining both lock members 2 and 13 in an angular disposition in relation to filling pieces 18.

The construction of the release mechanism of the lashing fitting as shown in FIGS. 6, 7 and 8 is such that the stud 7 is a shaft guided by bushings 28 and 31 and whose enclosed end is seated upon a compression spring 30. Upon the shaft of stud 7 is mounted a triggering piece 15, 29, 33 and locking stop 32. Locking stop 32 is bevelled on one side so that during the tensioning operation of spring 4 pin 6 acts against the bevelled surface of locking stop 32 which in turn compresses spring 30, thus allowing pin 6 to pass by locking stop 32. Triggering piece 15, 29, 33 is a bevelled plate the upper horizontal part 15 of which projects into a hole 16 in the end wall of the housing and the ends 29, 33 of which extend upon a lower horizontal plane than that of part 15 towards the open side of the housing, thus permitting the triggering mechanism to be activated from the end or from either side of the lashing fitting.

As appears from the Figures the lock members 2, 13 are both shorter and narrower than the filling pieces 18 in order to allow tolerance for slight misalignment, due to where or the introduction of foreign matter, of the lock members 2, 13 in relation to filling pieces 18. By this means the grave risk of accident due to incomplete disengagement of containers from the lashing fittings will be minimized.

An indicator shaped as a curved arm 21 and mounted in the box construction of the housing swings about a pivot pin 23 holding arm 21 by means of a locking washer 24. Indicator arm 21 is tensioned inwards from the housing 1 by means of a spring 25 mounted between the housing wall and the indicator arm itself. A cam, pin or similar member 27 is supported by shaft 3 in a position to contact the indicator arm 21 during rotation of the shaft and to push it outwardly in a revolving movement about pivot pin 23 to cause the outer end of indicator arm 21 to extend through an aperture 22 in the wall of housing 1 and thus visually to indicate the tripping of the lashing fitting. In the locking condition of lock members 2, 13 pin 27 is thus in abutting contact with indicator arm 21 to hold said arm in its extended position. Upon additional turning movement of shaft 3 pin 27 will be disengaged from indicator arm 21 which thus will be moved back within the housing by the action of spring 25. An abutment piece (not shown) is provided in a position in housing 1 diametrically opposed to tripping stud 7 in relation to shaft 3 for the purpose of preventing shaft 3 from being turned beyond one half turn from the starting position, said abutment piece corresponding to abutment piece 17 in the embodiment shown in FIGS. 2 to 5.

The lashing fitting according to this embodiment as shown in FIGS. 6 to 8 is disengaged in a similar way as the lashing fitting illustrated in FIGS. 2 to 4. The tripping or triggering piece 15, 29 or 33 is actuated either manually or with the aid of a tool through recess 16 in the end wall of the housing or, as far as parts 29, 33 are concerned, through the open side of the box-like housing construction. Pressure in a direction towards lock member 13 upon anyone of parts 15, 29 or 33 will call the shaft of stud 7 to further depress spring 30 thereby permitting pin 5 to pass by stop 32 during rotation of shaft 3 under pressure from spring 4. Rotation of shaft 3 will stop when pin 6 makes contact with the abutment piece 17 as shown in FIG. 3, and as shaft 3 will then have rotated through 180.degree., locking member 2 will once again be in alignment with filling piece 18 thus allowing unrestricted removal of locking member 2 from its location. To remove the lashing fitting from its suspension under a container shaft 3 is turned through the angle of relative angular displacement between lock member 13 and filling piece 18 until lock member 13 is aligned with its guide 18 and thus also is aligned with the elongate aperture in the corner casting. This turning movement is suitably performed manually by inserting a tool into bore 20 of the lower lock member 2.

In the embodiment shown in FIGS. 2 to 4 the total permissible turning movement of shaft 3 amounting to half a turn is divided into two equal stages viz. a locking stage and an unlocking stage, each stage comprising a turn of 90.degree., whereas in the embodiment illustrated in FIGS. 6 to 8 the turning movement is divided into two unequal stages depending on the desired angular displacement between lock member 13 and the filling piece 18. Thus, it has been found that in connection with an angular displacement of 30.degree. between locking member 13 and the filling piece 18 the first turning step of the lock members to the locking position preferably should comprise about 105.degree. whereas the second turning step of the lock members 2, 13 to the container-disengaging position should comprise about 75.degree.. However, these two different degrees of rotation can be arbitrarily chosen during manufacture of the lashing fitting by shifting the position of pin 5 in a direction respectively towards and away from lock piece 32 of tripping stud 7 said pin, as shown in FIGS. 7 and 10, being provided in a plane below the plane of locking pin 6.

The modified embodiment of the invention illustrated FIGS. 9 and 10 is functionally similar to the embodiment shown in FIG. 5, the lashing fitting of FIGS. 9 and 10 being adapted to be attached to stationary guide rails or similar arrangements on a loading platform such as the deck of a ship. For this reason the lashing fitting according to FIGS. 9 and 10 in a way similar to the construction shown in FIG. 5 is provided with only one lock member 2 extending from one side of housing 1 whereas the opposite side of the housing is provided with engaging members 9 extending from the housing, these members being in the form of locking plates, studs, flanges or the like which may be integral with the lower part of the housing. Thus, the lashing fitting according to this embodiment may be inserted by lateral shifting movement into engagement with stationary guide rails on the deck of a ship whereafter the upper arrow tip-like lock member 2 on the turning shaft 3 may be loaded or tensioned as described above by a half-turn revolving movement. When a container is lowered for placement onto the deck engagement with the lashing fitting will take place in the way as described above as soon as the tripping stud 7 is actuated for releasing the turning movement of lock member 2, the indicator 21 being caused to extend through aperture 22 in the housing to visually indicate the tripping of the lashing fitting. Detachment of lock member 2 from the superimposed container is obtained in the same way as in the previously described embodiment by activation of tripper or trigger piece 15, 29 or 33. In the embodiment illustrated in FIGS. 9 and 10 the turning movement of shaft 3 is performed in two equal steps each comprising 90.degree..

The expert will appreciate that further modifications of the invention will fall within the scope of the enclosed claims. For example, it is possible to pre-load the lashing fitting according to the invention to its initial state in which the shaft 3 is primed prior to attaching the lashing fitting to a container. Moreover, lashing fittings of the embodiment illustrated by reference to FIGS. 6 to 8 may also be placed in the upper corner castings of a container in order to receive a further container not withstanding the fact that from a safety point of view suspension of the lashing fitting from the bottom of a container is preferable. While the invention has been described by reference to some preferred embodiments in which the member exerting the turning action is a torsion spring, it is of course within the scope of the invention to use other means for performing the required turning action, such means, for example, being pneumatic means, electromotors, etc. However, the pure mechanical operating means as described appears to form the cheapest and safest solution of the problem.

Claims

What we claim is:

1. A fitting for disengagably securing a freight container to another container or to loading platform, said fitting being a separate unit comprising a housing and, extending therefrom, at least one twistlock member which in an initial position is insertable into an elongate aperture in a corner casting of a container, wherein the turning movement of the twistlock member is automatically tripped upon assembly of a further container with the fitting previously attached to a container or loading platform, a twist-exerting member for turning said twistlock member, said twist-exerting member being adapted to turn the twistlock member through an angle of 180.degree., said turning action being sub-divided into a first securing step and a second disengaging step, said securing step being automatically tripped upon assembly of a further container with said fitting by the depression of a tripping stud projecting through a hole in said housing for releasing the securing step of the twisting action of said twist-exerting member thereby to turn said twistlock member into a locking position within said corner casting.

2. The fitting as claimed in claim 1, wherein the twist-exerting member comprises a torsional spring which, from its nontensioned position, may be tensioned to said initial position.

3. A fitting as claimed in claim 1, wherein a locking pin is fixedly connected to the shaft of the twistlock member and in the tensioned initial position is retained by said tripping stud, said locking pin upon actuation of said tripping stud being free to pass past said tripping stud through a recess provided therein.

4. A fitting as claimed in claim 3, wherein a tripper piece is provided on said tripping stud and being accessible through a recess in the housing for manual operation of the tripping stud for releasing the disengaging stop of the turning movement so as to turn the twistlock member from the container coupling position, said pin connection to said torsion spring abutting against said tripping stud, manual operation of said tripper piece causing said tripping stud to be shifted to a position in which the pin is free to pass through said recess in the tripping stud to permit the twistlock member shaft to turn to a position in which the twistlock member is aligned with the elongate aperture of the corner casting and the container is adapted to be disengaged from said fitting.

5. A fitting according to claim 4, said fitting being a separate unit comprising a housing from which one twistlock member extends in either direction for simultaneously coupling the fitting with two containers placed one upon another with said fitting interposed, the two lock members being identically shaped and mutually connected by a common shaft extending through said housing.

6. A fitting according to claim 1, comprising a single lock member extending from said housing, the opposite side of the housing being provided with a locking plate, and a locking stud cooperating with stationary guides on a loading platform for detachable coupling of a container to said loading platform.

7. A fitting according to claim 1, wherein the housing comprises two assembled U-beam sections with shank ends of said sections in mutual contact and fastened by welding along the lines of contact, said U-beam sections being reinforced by struts welded both to each other and to the fastened shanks of the U-beam sections, the longitudinal axis of said through shaft extending in the same direction as said reinforcing struts, a handle being provided at one end of the sides of the housing formed by the web portion of one of said U-beam sections.

8. A fitting for disengagably securing a freight container to another container or to a loading platform, said fitting being a separate unit comprising a housing and, extending therefrom, at least one twistlock member which in an initial position is insertable into an elongate aperture in a corner casting of a container, the turning movement of the twistlock member being automatically tripped upon assembly of a further container with the fitting previously attached to a container or loading platform, a twist-exerting member for turning said twistlock member, said twist-exerting member being adapted to turn the twistlock member through an angle of 180.degree., said turning action being subdivided into a first securing step and a second disengaging step, said securing step being automatically tripped during assembly of a further container with said fitting by the depression of a tripping stud projecting through a hole in said housing for releasing the securing step of the twisting action of said twist-exerting member thereby to turn said twistlock member into a locking position within said corner casting, wherein an indicator is provided to indicate the tripping of the lock means of the fitting and the coupling of the respective containers to said fitting and thereby to each other and/or a loading platform.

9. A fitting according to claim 8, wherein the indicator is an arm journalled for swinging movement about a pivot and during turning of the lock member to the coupling position being acted upon by a cam, and a pin provided on said shaft for shifting to a position extending from said housing through a recess therein.

10. A fitting according to claim 9, wherein a pressure spring urges said indicator towards its initial position indicating that the lock means of the fitting does not perform a coupling action.

11. A fitting for disengagably securing a freight container to another container or to a loading platform, said fitting being a separate unit comprising a housing and, extending therefrom, at least one twistlock member which in an initial position is insertable into an elongate aperture in a corner casting of a container, the turning movement of the twistlock member being automatically tripped upon assembly of a further container with the fitting previously attached to a container or loading platform, a twist-exerting member for turning said twistlock member, said twist-exerting member being adapted to turn the twistlock member an angle of 180.degree., said turning action being sub-divided into a first securing step and a second disengaging step, said securing step being automatically tripped during assembly of a further container with said fitting by the depression of a tripping stud projecting through a hole in said housing for releasing the securing step of the twisting action of said twist-exerting member thereby to turn said twistlock member into a locking position within said corner casting, wherein the lock members extending in opposite directions from said housing being mutually angularly displaced on said common shaft.

12. A fitting according to claim 11, wherein the relative angular displacement of said lock members is in the range of between 10.degree. and 170.degree..

13. A fitting according to claim 11, wherein the lock members of the fitting in the tensioned starting position are tensioned for turning 180.degree. in two unequal steps determined in dependence upon the actual angular displacement between the lock members.

14. A fitting according to claim 13, wherein when the angular displacement between the lock members is 30.degree. the first turning step of the lock members to the coupling position comprises about 105.degree. and the second turning step of the lock members to the container disengaging position comprises about 75.degree..