The present invention relates to an arrangement for blocks which exhibits means for the detachable attachment of blocks to one another in pairs with the top side and under side and lateral sides of respective blocks.

Previously disclosed blocks of the aforementioned kind do not exhibit the possibility of being connected together at will in optional directions and with any sides on the square blocks. For example, building blocks which can be used in the context of play and/or for model building are previously disclosed through US 4,129,960 A, US 5,683,283 A, GB 2,136,700 A and EP 0,181,855 Al.

The square building block previously disclosed through US 4,129,960 A exhibits five identical sides which have recesses adapted to accommodate pins projecting from the bottom side of additional blocks. The possibility of connecting any sides of the blocks at will is limited, therefore, because only one of six sides in each block exhibits projecting connecting means, and because nothing is stated or shown about extra means for connecting the blocks, for example side-by-side, bottom-to-bottom or top-to-side.

US 5,683,283 A relates to building blocks which have four side walls and one top side and one bottom side, in conjunction with which the top side has projecting connecting means, although these can only be connected together directly to the underside of an additional building block intended for connection. Lateral connection takes place by means of long connecting rods, which can also be used for connection between the top side and the under side of spaced building blocks. The connection possibilities in optional directions are limited in this way, for example for connecting the blocks top-to-side without any extra means.

The blocks in accordance with GB 2,136,700 A are entirely lacking in possibilities for lateral connection, and the connection of blocks is thus only possible between the top side and the under side of blocks which meet one another.

This is the same principle encountered in the familiar blocks that are sold under the LEGOTM trademark.

EP 0,181,855 Al relates to homogeneous building blocks which consist essentially of wood and exhibit projecting connecting means on two mutually adjoining sides and matching recesses in the remaining side/sides. Problems are nevertheless encountered in connecting before or afterwards, because the connecting means concerned are fixed.

The direction in which the blocks face is also critical, in respect of both the connection function and appearance, on the built product, because the connecting means concerned are alternately projecting connecting means and inverted connecting means with hollow form.

The principal object of the present invention is thus, in the first instance, to make available building blocks which are intended to be capable of being connected together simply and reliably from different desired directions, and which exhibit a simple design with regard both to their manufacture and to their application.

The aforementioned object is achieved with an arrangement in accordance with the present invention, which is characterized essentially in that at least one of the block's lateral vertical sides exhibits a frame-forming connecting part, in that the upper side of the block exhibits projecting preferably irregularly shaped connecting elements, in that the under side of the block is hollow and exhibits a number of centrally located and preferably irregularly shaped counterpressure devices, and in that the aforementioned vertical side and the under side, which exhibit a frame- forming connecting part, are capable of direct connection to

an upper side of a complementary block and to a complementary block via an interjacent connection.

The invention is described below with reference to ( the accompanying drawings, in which: Fig. 1 shows a square building block in accordance with the invention viewed at an angle from above and in a direction from one of its corner edges; Fig. 2 shows the aforementioned building block viewed at an angle from below; Fig. 3 shows two such building blocks in a connected position, viewed at an angle from above; Fig. 4 shows a view of the aforementioned blocks from above; Figs. 5-6 show the top connection and edge connection of pairs of building blocks; Fig. 7 shows the edge and bottom connection of pairs of building blocks; Fig. 8 shows a building block viewed at an angle from below and with accommodated detachable connections which can be utilized for bottom-to-side connection as shown in Fig. 7, for example, and for lateral connection as shown in Fig. 9; Fig. 8A shows perspective views of different loose connections; Figs. 9-12 show pairs and quartets of side- connected blocks viewed at an angle from above and at an angle from below; Figs. 13-15 show square building blocks with connecting loose additional connections; Fig. 16 shows a building block with an extension frame; Fig. 17 shows a double block viewed at an angle from below; Fig. 18 shows a single block viewed from one of its sides;

Fig. 19 shows an example of a block with a smooth lateral surface; and Figs. 20-21 show examples of connections with a smooth top surface and respectively with surfaces which exhibit connecting elements on their long sides and top side.

The invention relates to special blocks which are so arranged as to be capable of being used to build objects for play purposes, but which can also be used to make prototypes. More specifically, the present invention relates to an arrangement 1, as shown in Fig. 1, for a square building block 2 which exhibits means for the detachable attachment of blocks 2,2 (1) to one another in pairs.

In accordance with the invention at least some of the block's lateral vertical sides A-D and the under side E exhibit internally a permanent frame-forming connecting part 3.

The upper side F of the block 2 exhibits projecting and preferably irregularly shaped connecting elements 4, 4 (1), 4 (2), 4 (3).....

The under side E of the block 2 is hollow and exhibits a number of centrally located and preferably irregularly shaped counterpressure devices 5,5 (1),...

The aforementioned vertical sides A-D of a block 2 and the bottom side E are thus, in accordance with the invention, capable of direct attachment to an upper side F of a complementary block 2 (1) and to a complementary block 2 (1), 2 (2), 2 (3)...... via a detachably applied connection 6,6 (1) ; 7 situated between the two blocks 2,2 (1) ; 2 (1), 2 (2); 2 (3)......

The aforementioned frame-forming connecting part 3 exhibits a bottom 8, which faces in a direction in 9 towards the internal cavity 10 of the block, and which closes the passage leading into the same. An opening in the aforementioned connecting part 3 is thus open and faces in a direction out from the aforementioned block 2. The bottom

side E of the aforementioned blocks 2,2 (1) lacks a closing bottom and is entirely open from below in a direction in towards the internal cavity 10 of the block.

The depth 11 of the aforementioned frame-forming connecting part 3 is the same as or greater than the projecting height 12 of the connecting elements 4-4 (3) that are arranged on the block 2,2 (1) and project in a direction out 13 from the aforementioned block and are perpendicular to the upper side F.

In accordance with an illustrative example of the invention, at least two or three of the four vertical lateral surfaces A-D of the block each exhibits its own frame-forming connecting part 3. The third and/or fourth vertical lateral surface can in this case be smooth, so that the product that is built by means of the blocks 2,2 (1).... assumes a smooth surface along the side of the product that is visible and can be observed, for example as shown in Fig. 19.

The aforementioned connecting elements 4-4 (3) projecting from the block 2,2 (1).... are formed by a number of cross-like raised areas which project in a direction 13 from a flat surface F thereon, i. e. along the perpendicular to the upper side of the aforementioned flat surface F. In accordance with a preferred illustrative example, at least four connecting elements 4-4 (3) are arranged on the upper side F of a building block 2,2 (1) of the kind in question, preferably at the respective corners 14-17 of the building block. An aforementioned counterpressure device 5,5 (1), 5 (2).... is formed by its own upright, which exhibits cross- like cross-sectional form and is attached to the centre of the block in the aforementioned internal cavity 10 of the block. The connecting elements 4-4 (3) of the connected block 2,2 (1) are arranged against the sides 5A-5H of the aforementioned upright in such a way that they interact with one another in the connected position I, as shown in Figs. 3- 4.

Illustrated in Figs. 1-16 are blocks where only a single connecting upright is arranged at the centre of the block.

Illustrated by way of example in Fig. 17 is a double block 2, which is provided with no fewer than three separate upright-shaped counterpressure devices 5-5 (2), which are arranged in a row distributed along the centre axis 18 of the block at uniform distances 19 from one another in the internal cavity 10 (1) of the block. Connecting elements in a connected block are so arranged as to interact with the sides of the aforementioned upright.

The aforementioned connecting elements 4-4 (3) and counterpressure devices 5,5-5 (2) are displaced from one another in the illustrated example, i. e. connecting elements 4-4 (3) are each rotated through 45° about their vertical central axis 21,21 (1), 21 (2), 21 (3) and extend in a common direction 13,22. Other forms of connecting elements 4,.... can also occur.

The counterpressure devices 5-5 (2) preferably exhibit square form on their legs 23,24,25,26, whereas the legs 27,28,29,30 of the connecting elements exhibit rounded form at their outer ends. Effective, tight connection of the aforementioned connecting elements 4-4 (3) and the counterpressure devices 5-5 (2) with one another is permitted in this way in blocks 2,2 (1) stacked on top of one another.

The counterpressure devices 5 can also exhibit forms other than those illustrated and described.

The expression connection is used here to denote that at least three of four edges of each square block 2, 2 (1).... must meet if they are connected together with one another with only invisible connections or without loose connections. There is no need for full edges, of course, because on occasion two edges with different lengths meet. In the best case, four edges with the same length meet in each block; e. g. when these are connected together top-to-bottom.

The blocks 2,2 (1)... are connected together at a number of contact points between connecting elements 4, 4 (1)... from the first block and inner block walls and the upright 5 to the next block. It is possible to change the number of contact points by changing the form of the connecting element 4 and the upright 5.

It is thus possible, as shown in Figs. 5 and 6, to connect together the top F to the side B and D by pushing in a number of the connecting elements 4-4 (3) on the first block into the indented frame-forming part 3 of the sides of the next block. The indented frame part 3 in the sides must not pass all the way through the block.

A step in the side E, which extends into the block 2, can be seen in Fig. 2. It starts precisely where a connecting element is pushed in after the connection of two blocks top-to-bottom. This acts as a brake when it is wished to connect the blocks from bottom-to-bottom or from bottom- to-side of the next block with the help of an external connection as shown in Figs. 8 and 8A. This is known as side connection 6. The thickness of the side connection 6 is at least double the thickness of the connecting element 4. As far as side connection is concerned, it is important for the thickness and external dimensions to match the blocks and their form and design.

Figure 18 shows the block from the side. It is possible to see the thickness of the connecting elements 4, 4 (1) in the upper part. On the side of the actual block there is an indented part which is sufficiently large for two connecting elements situated alongside one another to be accommodated therein. The blocks shown in Figs. 5 and 6 can be connected together by pushing in two free connecting elements 4-4 (3), which are situated alongside one another, into the indented frame-forming part, which has a depth at least as great as the height of the connecting elements.

In addition to side connection 6, there is also top connection 7, see Fig. 16, which connects together two blocks top-to-top. The external dimensions are as great as the external dimensions of the block. The internal dimensions are adapted to make contact with connecting elements 4,4 (1), 4 (2), 4 (3)... and to permit connection together. The thickness is at least double the thickness of the connecting elements 4.

The surface on the side of the block 2,2 (1) shown in the Figures is half as great as the surface of the top of the block. It is also possible to choose to have a larger size, i. e. with an area as large as the top of the block. In this case, four connecting elements 4,4 (1), 4 (2), 4 (3) are accommodated in the indented parts 3 on the sides A-D of the block. See Fig. 15.

The blocks 2,2 (1)... are made in the first instance of plastic material and in any desired colours, and in order to make the block as light as possible and, at the same time, to consume less material, which may be any material at all, holes can be made at those points which do not affect the design. This also reduces the risk of suffocation in the event of children putting blocks in their mouth.

The invention makes it possible to connect together blocks 2,2 (1) at will from different directions with or without external connection 6,6 (1) ; 7. If the blocks 2,2 (1) are to be connected together side-to-side, side-to-bottom, bottom-to-bottom or top-to-top, one or other of the external connections 6,6 (1), 7 will be required. If, on the other hand, the blocks are to be connected together top-to-bottom or top-to-side, no extra connections will be required. The expression connecting together is used here to denote that at least three of the four side edges of each block meet after connection, as indicated above. This need not involve the entire edge, since there are occasions on which two side

edges with different lengths meet. In the best case, four side edges with the same length meet on each block, e. g. for top-to-bottom connection.

The function of the connecting elements 4,4 (1), 4 (2), 4 (3),... and counterpressure devices 5,5; 5 (2), for example in the form of uprights and inner walls of the block, is to create contact points between connecting elements 4, 4 (1), 4 (2), 4 (3) in a first block and the upright 5 and inner walls of a second block to permit their connection together top-to-bottom, regardless of the form and size of the connecting elements 4 and the upright 5. The number of contact points can be varied by changing the forms and sizes of the upright and the connecting elements.

The function of the connecting elements 4,4 (1), 4 (2), 4 (3),... and the frame-forming connecting part 3 on the sides of the block 2 is to create contact points between the connecting elements in the first block 2 and inner walls of the indented connecting part 3 on the side of the next block 2 (1) in order to permit connection top-to-side. The dimensions, depth and form of the indented part 3 of the sides of the block may have any appearance, subject to the requirement of being able to connect the blocks together in the right way in accordance with the invention. The frame- forming connecting parts 3 on the sides A-D need not be centrally positioned.

In the connected position I, a leg 54 of an interacting cross-shaped connecting element 4-4 (3) is so arranged as to be accommodated with its essentially rounded connecting part 55 between pairs of legs 56 for the purpose of exerting pressure against them, while at least one opposing leg 57 in the respective cross-shaped connecting element 4-4 (3) is so arranged as to be accommodated in a meeting block and to make contact with the inner wall 58 of the aforementioned block for the purpose of exerting pressure against it.

The depth 11 of the indented frame-shaped part 3 in the sides A-E of the block 2 shall be at least as great as the thickness 12 of the connecting element 4-4 (3), and the internal dimensions of the aforementioned indented part 3 of the vertical sides A-D of the block are as great as the external dimensions of two of the four connecting elements that are situated alongside one another. This makes it possible to connect together the blocks top-to-side with the help of connecting elements without any extra connection. It is possible to design the block so that four block heads 4- 4 (3) can connect the blocks together top-to-side. In this case, the surface of the side can be as large as the surface on the top of the block. The block is a cube. The indented part on the vertical sides of the block may not, as stated above, extend all the way through the block. It must be possible to connect six such blocks 2 at the same time to all six sides of a similar block, either only with connecting elements 4,4 (1)... or with only external connections.

The thickness 12 of the connecting elements must be less than the minimum distance 50 between the block head 4 and the block edge, and the minimum distance 50 between a block head and the edge must be half as great as the minimum distance 51 between two block heads 4,4 (1) situated alongside one another. The distance between the outer edge of the indented frame-shaped part 3 on the sides of the blocks and the edge of the block must be as great as the dimension 50.

The largest inner wall on the side E has a dimension 53 equivalent to the longest external dimension on two surrounding connecting elements 4,4 (1), and the depth is at least equivalent to the thickness of the connecting element 4. The next inner wall has a smaller dimension 52 and commences precisely after the first inner wall. This functions as a stop for a connection 6,6 (1) if the blocks

are to be connected together bottom-to-bottom or bottom-to- side.

The connection 6,6 (1) can have any appearance, for example it can have the form of a dog's leg or a block with projections on two or three of its sides, to permit the connection together of two blocks side-to-side or side-to- bottom or bottom-to-bottom. On the other hand, the connection 7 for the upper side of the block 2 may not have any appearance. The external dimensions must, in fact, be as great as the external dimensions of the block. The internal dimensions must be adapted so that contact points between connecting elements and the inside of the connection 7 are created to permit connection together. The aforementioned thickness must be at least double the thickness exhibited by the connecting elements 4.

It is thus possible to connect together six blocks 2 at the same time to form a single block 2 with the help of only connecting elements 4 or with only connections 6,6 (1), 7 in the aforementioned single block.

Figs. 8A, 13,14 and 16 show examples of internal frame-shaped connections 6,6 (1), 7 to permit blocks to be connected together in pairs in a concealed or visible fashion.

Larger and smaller blocks can be manufactured in accordance with the invention as base blocks, and the design can also include half blocks and quarter blocks, although these are not shown here. In these cases, it is important to be able to retain the side connection function, which is achieved with the help of one or two block heads. These can lack a counterpressure device in the form of an upright 5.

These can be used subsequently in turn as a base block with which to make larger blocks.

The function and the nature of the invention should have been appreciated from the foregoing.

The invention is naturally not restricted to the embodiments described above and illustrated in the accompanying drawings. Modifications are possible, in particular in respect of the nature of the various components, or by the application of equivalent technology, without departing from the scope of the protection afforded to the invention as defined in the Patent Claims.