FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a locking device for interlocking parts separable from each other, said device comprising at least a first locking means arranged on a first one of said parts and having a projection and at least a second locking means arranged in the second part, cooperating with the first one and having a correspond¬ ing recess.

Thus, the invention is directed to locking devices for interconnecting parts or members of arbitrary types broadly spoken with in very different fields of use, but it will in the following by way of an ex¬ ample and for illustrating the problem according to the invention be described in connection with interlocking of parts or members of enclosures, in particular containers, in which the lid and/or the bot¬ tom member may be separated from the walls of the container.

A locking device of the type mentioned in the introduction is already known by the Swedish patent application 9001887-0, and it is there arranged to interlock the lid and/or the bottom member with respect to a foldable wall arrangement of a foldable container. Although this locking device functions well a mutual displacement of the first and second locking means is required when the projection of the first locking means is brought out of engagement with the recess of the second locking means, namely the wall arrangement has to be folded to a certain extent before it may be lifted away from the bottom member, since the projection is fixed on the bottom member,

and this may for certain users having special enclosure handling systems for procedures be a drawback, since the latters could be simplified by avoiding said requirement of partial folding of the wall arrangement before the separation of the bottom member. The same problem occurs of course also when the wall arrangement and the bottom member are interlocked.

Thus, it would be desirable to provide a locking device which per¬ mits the wall arrangement to be lifted straight upwardly without changing the basic shape thereof, i.e. folding thereof, from the bottom member when these are separated from each other and lowering thereof into the bottom member when these parts are as¬ sembled. This is also valid for containers being not foldable, in which for the rest a locking device according to said Swedish patent application would not do, as well as all other types of enclosures and the like, where the handling thereof would be considerably facilitated by the possibility to remove the interlocking of the parts without a relative movement thereof so as to then separate them through a translation movement, preferably substantially in parallel with the extension of one of the parts.

SUMMARY OF THE INVENTION

The object of the present invention is to find a remedy to the incon- venience mentioned above, which may be experienced in certain uses of a locking device defined in the introduction for interconnect¬ ing parts concerning interrupting and establishing of the interlocking therebetween, so that these operations may be accomplished in a simplified way while maintaining a high reliability of the intercon- necting function thereof.

This object is in accordance with the invention obtained by the fact that in a locking device of the type discussed above the projection is arranged movable with respect to the first part and displaceable out of and into a locking engagement with the recess of the second part without any movement of the parts with respect to each other.

Accordingly, thanks to the movability of the projection provided in accordance with the invention, so that this is displaceable com¬ pletely out of arid into locking engagement with the recess of the second part without any requirement of relative movement of said parts, it is possible to bring different parts to be interlocked or separated in a very easy way towards each other to the position suited for interlocking and away from each other, respectively.

In the case of a container according to the Swedish patent publica- tion mentioned above, foldable or not, it is by applying a locking device according to the invention accordingly possible on one hand on separating the wall arrangement from the bottom member after bringing the projection out of the recess of the wall arrangement to lift the wall arrangement straight upwardly, and on the other on interlocking thereof lower the wall arrangement already having the shape aimed at straight downwardly into the bottom member and then bring the projection of the locking device into the recess of the wall arrangement for establishing the interlocking.

If machines are intended to be used for this procedure, considerable savings of costs may of course be done therethrough, since it is only necessary to provide a hoist or similar lifting arrangement for taking care of the displacement of the wall arrangement, while it was previously necessary to have more complicated arrangements or control devices so as to control different types of movements of the wall arrangement in different directions.

According to a preferred embodiment of the invention the first lock¬ ing means in the locking device is in the active locking position thereof spring-loadedly actuated into engagement in the recess and movable out of this engagement while overcoming this spring-load. Thus, it is through this possible to move the projection out of the engagement with said recess while overcoming said spring-load for easily separating the parts, but a secure interlocking thereof will nevertheless be obtained thanks to said spring-load function to maintain the projection in the recess.

According to another preferred embodiment of the invention the projection of the first locking means is carried by an element, which is pivotally arranged on said first part, whereby it is after pulling the projection out of said recess possible to pivot the element carrying the projection, so that this may be released without any risk that the projection will by mistake or through the spring-load present unin¬ tentionally be brought into the recess again.

According to a further preferred embodiment of the invention the locking device is provided with an elongated tongue-like element arranged to carry the projection, this tongue-like element is ar¬ ranged to provide said spring-load by having a leaf spring charac¬ ter, and the projection is made movable out of said engagement by bending the tongue-like element. The spring-load present in the pre- ferred embodiment discussed above is obtained in a very simple and thereby inexpensive and reliable way.

According to a still further preferred embodiment of the invention the element carrying the projection and thereby the projection are arranged to be operated by gripping and pulling a grippable operat¬ ing member connected to the element carrying the projection and being formed by a freely flexible flap-like element, which may through a recess therein be heeled or struggled onto a projection. A possibility to a very simple operation of the locking device is in this way obtained by simply pulling the flap-like element and releasing it, respectively, and thanks to the free flexibility thereof it may be easily gripped without constituting any obstacle or demanding any room in the interlocked state of the parts, since it may be freely pressed against said first part.

The simplifications mentioned above obtained by the locking device according to the invention with respect to interlocking and separat¬ ing of different parts are as indicated in the introduction of course also transferable to fields of use differing completely from the one illustrated with reference to the Swedish patent application 9001887-0, and the same is valid for the advantages of the different preferred embodiments of the invention discussed above.

Further advantages and preferred features of the invention will ap¬ pear from the rest of the dependent claims as well as the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a descrip¬ tion of a preferred embodiment of the invention cited as an example. In the drawings:

Fig 1 is an exploded perspective view illustrating a container, onto which the locking device according to the invention is applied,

Fig 2 is an enlarged perspective partial view of a part of the bottom member, the wall arrangement and the lid of the container in Fig 1 in the interlocked state,

Fig 3 is a view corresponding to Fig 2 of the container with the parts mutually separated for a complete separation or an interlocking following thereupon,

Fig 4 is a partially sectioned perspective partial view of a portion of a container according to Fig 1 in the folded state thereof,

Fig 5 is a side elevation of the first locking means of the locking device according to Figs 1-4 in the free state,

Fig 6 is a partially sectioned view of the locking means in Fig 5 mounted on a part of the container and in the interlocking position, and

Fig 7 is a perspective view of the locking means according to Fig 5.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

The container illustrated in Fig 1 comprises a bottom member 1 , a foldable wall arrangement 2 and a lid 3. The container has in the example a parallelepipedic basic form. The wall arrangement 2 is in the unfolded state of the container locked with respect to the bottom member 1 in a way which will be described hereinafter, and the lid 3 is securable to the wall arrangement 2 while closing the container. The lid and the bottom member as well as the wall arrangement may in the practice consist of sheets of plastic, plywood or the like and edge and corner garniture of metal secured thereto. It is suit¬ able to once again underline that the locking device according to the invention is not at all restricted to the use for interlocking the bot- torn member, the wall arrangement and the lid of such a foldable container with respect to each other, but this use is here only de¬ scribed for illustrating one of many possible uses of the locking device according to the invention and explaining the invention.

The wall arrangement 2 has in the four corners thereof hinge arma¬ tures and furthermore two opposite walls of the wall arrangement are divided into two hingedly interconnected parts 4, 5, which in their turn are hingedly connected to the other walls 6 of the wall arrangement 2. The wall arrangement is thereby foldable by pivoting the wall parts 4, 5 inwardly towards the center of the wall arrange¬ ment at the same time as the walls are moving towards each other. The walls 6 and wall parts 4, 5 will be directed substantially paral- lelly while forming a comparatively thin package (see the middle of Fig 2) in the completely folded state of the wall arrangement 2. The container described so far corresponds to the one according to the Swedish patent application 9001887-0.

Two first locking means 1 1 are arranged on preferably surrounding edge flanges 7 and 8, respectively, of the bottom member 1 as well as the lid 3 at each of two opposite edges 9, 10, which flanges extend substantially perpendicularly to the plane of the bottom member and the lid, respectively. Reference is now also made to

the rest of the Figures. The first locking means is formed by an elongated tongue-like element 12, which at one end thereof is pivo- tally connected through a rivet 13 to the outside of the respective edge flange about an axis being substantially perpendicular to the respective edge flange 7, 8. A projection 14 protruding substantially perpendicularly is secured to the other end of the tongue-like ele¬ ment 12. The tongue-like element 12 is of a material, for example spring steel, which gives it a leaf spring-like character, and it has in a free, relaxed state, when it is not mounted to any edge flange yet, a slightly curved extension (see Fig 5), which means that it is de¬ signed to bear substantially flat towards the outside of the edge flange under pretension in the locking state (see Fig 6) in which it is applied on the edge flange. The advantages thereof will be ex¬ plained further on.

Second locking means 17 in the form of through recesses are ar¬ ranged at the upper 15 and the lower edge 16 of the walls 6 of the wall arrangement. These recesses are carried out in and reinforced by metal armatures 18 arranged on the walls 6. The recesses 17 are so located with respect to the distance to the upper and lower edge, respectively, of the walls and the corners of the wall arrangement, that the projection 14 of the tongue-like element 12 will fit therein when the tongue-like element extends substantially in the longitudi¬ nal direction of the edge flange and the bottom member and the lid, respectively, is brought into the desired position for interconnecting it with the wall arrangement. The recess 17 is designed elongated in the direction of said upper 15 and lower 16 edge, respectively, i.e. substantially perpendicular to the direction of the movement of approaching and removing, respectively, of on one hand the bottom member or the lid and on the other the wall arrangement. A dis¬ placement of the projection 14 into the corresponding recess 17 is facilitated thereby, but a substantial movement of the lid and the bottom member, respectively, in the direction away from the wall arrangement is nevertheless prevented in the interlocked state.

It is shown in Fig 2 how the bottom member 1 and the lid 3 are interlocked with respect to the wall arrangement 2 by the coopera-

tion of the first and second locking means. It appears from Fig 3 that the respective edge flange 7, 8 has a second recess 19, which is arranged to come to a substantially completely corresponding overlap of the respective recess 17 in the wall arrangement in the mutual position of the wall arrangement and the bottom member and the lid, respectively, so that the projection 14 is arranged to grip through the recess 19 in the edge flange in question as well as the recess 17 in the wall arrangement in the interlocking state of the locking device.

The projection 14 has a shape tapering slightly towards the extrem¬ ity thereof so as to facilitate the introduction thereof in the recesses 17 and 19. A flap- or strip-like element 20 of a freely flexible mate¬ rial, such as for example a substantially inelastic plastic, is heeled or struggled onto the projection 17. The flap-like element 20 is intended to function as a member for operating the tongue-like element 12 and thereby the projection 14 by being gripped and pulled substantially in the direction of the heeling thereof onto the projection. Thanks to the free flexibility of the flap-like element 20 this may be gripped easily in the interlocking state (see Fig 6), but it still gives easily way and may be pressed flat against the outer surface of the respective edge flange if required and is accordingly not an obstacle in any way.

The locking according to the invention functions in the following way: we assume that the wall arrangement 2 and the bottom mem¬ ber 1 are to be interlocked. It is firstly ensured that the first locking means 1 1 are located in the position according to Fig 3 by pulling the flap-like element 20 in the direction away from the edge flange 7 while bending the leaf spring formed by the tongue-like element 12, so that the projection 14 leaves the engagement with the recess 19, and the tongue-like element 12 is then pivoted with respect to the edge flange about the pivot point defined by the rivet 13, so that the projection 14 after releasing the flap-like element 20 will bear from the outside against portions 23 of the edge flange 9 surrounding the recess 19. The wall arrangement 2 is then lowered straight down¬ wardly towards the bottom member inside the edge flanges 9 and so

that the lower edge thereof arrives in a groove 21 extending in the bottom member internally of the edge flange and parallelly thereto. When this is done the flap-like element 20 is gripped again and the tongue-like element 20 is pivoted so that the projection 14 arrives just in front of the mutually overlapping recesses 19 and 17, where¬ upon releasing the flap-like element 20 means that the projection 14 is pressed by the inherent spring force of the tongue-like element 12 through the two recesses and arrives to flat, biased bearing against the outside of the edge flange 9 (see the position according to Figs 2 and 6). The pretension or biasing produced by the shape of the element 12 in the free, relaxed state thereof ensures a permanently flat bearing of the element against the enclosure part and it avoids thereby the risks of hooking into other containers or the like and being damaged or causing damage during loading or the like. When it is then desired to separate the wall arrangement from the bottom member starting from the position according to Fig 2, the flap-like element 20 is gripped and the tongue-like element 12 is bent away from the edge flange and pivoted to the position shown in Fig 3. The wall arrangement may then without any problem be lifted straight upwardly and away from the bottom member without any require¬ ment of a preceding folding thereof. Moreover, the first locking means is already located in a position which later on immediately allows lowering of the wall arrangement into the bottom member for interlocking thereof. It is evident that the interlocking and the sepa- ration, respectively, of the lid and the wall arrangement is carried out in an analogous way.

It appears from Figs 1 , 2 and 3 that the locking means on the bot¬ tom member and at the lower edge of the wall arrangement are arranged displaced in the extension direction of this edge with respect to the locking means on the lid and at the upper edge of the wall arrangement. The reason for this is that the first locking means on the lid shall be able to be used for interlocking the lid and the bottom member while gripping into further recesses 22 in the edge flange 7 of the bottom member without the formation of any obstacle by the locking means of the bottom member, so that the lid and the bottom member in the interlocked state according to Fig 4 form a

substantially closed box, the volume of which is mainly predeter¬ mined by the localization of the first locking means on the lid and the further recesses 22 in the bottom member. The space formed inside the box is intended to receive the foldable wall arrangement. It will in this way be possible to transport the container in a very compact state back to a supplier for refilling it with goods. Thus, the first locking means on the lid then fulfils a double function by secur¬ ing the lid to the wall arrangement in the unfolded state of the con¬ tainer as well as to the bottom member in the state in which the box is formed. The edge flange 8 is arranged to describe a slightly longer and wider frame than the edge flange 7 so as to make it possible to bring the edge flange 8 outside the edge flange 7 in the position according to Fig 4. It would of course also be possible to see to that the relationship between the edge flanges would be the reversed and arrange further recesses 22 in the edge flange 8 in¬ stead, so that the first locking means on the bottom member would be those which interlock the lid and the bottom member when said compact box is formed.

The invention is of course not in any way restricted to the preferred embodiment described above, but several possibilities to modifica¬ tions thereof would be apparent to a man skilled in the art without departing from the scope of the invention.

It would for example be possible to provide the spring-load of the element carrying the projection through any other spring, for exam¬ ple a tension spring, and said element could also be rigid and mov¬ able only by a translation movement.

It is natural that it is the outer one of the two parts partially over¬ lapping each other that has the first locking means and the inner one that has the second locking means when a container is con¬ cerned, but the reversed arrangement is of course also possible within other applications.

The shapes of the different parts included in the locking device according to the invention may of course differ from what is shown

in the drawings, especially the shape of the projection, the element carrying the projection and the recesses. The number of locking means could also be arbitrary.