ELEMENT

The present invention relates to a building block and a system of building blocks for the purpose of constructing playful spacious environments, tracks, mazes and the like that may challenge motor skills as well as cognitive skills and entertain children at ages 1 -5 years. The system of building blocks comprises a connector for connecting the individual building blocks of the system.

BACKGROUND

In order to stimulate development of motor and cognitive skills of children, a child needs physical as well as mental challenges. Further, challenges need to be inspiring, fun, motivational and adaptable to fit the age and skill of the child. As an even further requirement, challenges need to be safe and designed such that it does not harm or frighten the child.

One way of stimulating the development of children's motor and cognitive skills, in a safe and motivating manner, is by creating environments of walls and obstacles which may be of a soft material such that the child is not hurt if hitting the object. Such an environment sometimes referred to as enhanced environment may be obtained by the use of foam building blocks, which in some cases are designed to fit together by the use of recess and protrusions or hook-and-loop fasteners such as Velcro.

Some children however, especially children suffering from cerebral palsy, autism spectrum, ADHD, learning disabilities and the like may have a strong indisposition against surfaces with unfamiliar or diverse feel, e.g. hooks and loops or recess and protrusions on a flat surface. Further uncovered protrusions may pose an undesirable safety risk. Thus, it will be highly preferred to limit protrusions or similar on any free surfaces.

SUMMARY

In creating a stimulating environment for playing children, there is a need for a system that allows connecting building block but leaving free surfaces with limited undesirable objects. Accordingly, a building block system is provided. The building block system comprising a plurality of building blocks and at least one connector element.

The plurality of building blocks includes a first building block and a second building block. Each building block comprises a first surface, and a second surface adjacent to the first surface. The first surface comprises a first recess, wherein the first recess extends through the second surface.

The connector element is an elongated element, and the connector element has a first part proximate to a first end of the connector element and a second part proximate to a second end of the connector element. The first part comprises a first protrusion and the second part comprises a second protrusion. Each of the first part and the second part is adapted to mate with the first recess, such that when the first part or the second part is inserted in the first recess of the first building block, the connector element is restricted from movement relative to the first building block in at least a plane parallel to the first surface of the first building block.

The second surface of each building block comprises a second recess. The second recess extending through the first surface and the second recess being shaped to allow mating of the first part and the second part, such that when the first part or the second part is inserted in the second recess of the first building block, the connector element is restricted from movement relative to the first building block in at least a plane parallel to the second surface of the first building block.

Also disclosed is a building block, such as a building block of the plurality of building blocks of the building block system, such as the first building block and/or the second building block. The building block comprises a first surface and a second surface adjacent to the first surface.

The first surface comprises a first recess. The first recess extends through the second surface. The first recess is shaped to allow mating of a first part of a connector element, such that when the first part is inserted in the first recess the connector element is restricted from movement relative to the building block in at least a plane parallel to the first surface,

The second surface comprises a second recess. The second recess extends through the first surface. The second recess is shaped to allow mating of the first part of the connector element, such that when the first part is inserted in the second recess the connector element is restricted from movement relative to the building block in at least a plane parallel to the second surface.

It is an advantage of the present invention that it provides a building block system, where building blocks can be connected with a universal connector element and building blocks can be connected to form a three-dimensional environment.

The invention provides variation and individual customization, and thus, provides an environment that facilitates practice of both motor and cognitive skills. Challenging coordination between the mind and body, the present invention strengthens memory, attentiveness and general learning capabilities.

The invention is especially fit for children suffering from brain disorders such as CP. However, the advantages of the inventions hold for any child, or even adults.

The plurality of building blocks may comprise a plurality of different types of building blocks such as a plurality of different shapes, such as at least two different shapes, such as at least three different shapes, such as at least four different shapes. The plurality of different shapes may include mats, logs, cubes, cuboids, prisms, cylinders, and/or pyramids. Different shapes provide the possibility of constructing different environments and constructions.

The plurality of building blocks may have several sizes, such as dimensions between 10-100 cm, such as 20-80 cm, such as 30-60 cm.

The plurality of building blocks may comprise different building blocks having different weight such as weight in the range of 0.1 -5.0 kg, such as in the range of 0.2-3.0 kg, such as in the range of 0.5-2.0 kg. Weight of the building blocks preferably should be such that a child is able to move the building blocks around.

The plurality of building blocks may comprise different building blocks having different softness, ductility and/or tactility. The plurality of building blocks may be resilient building blocks, such as elastic or flexible. E.g. the plurality of building blocks may be made from a foam material, such as EVA foam. Making the building blocks in a resilient material provides a reduced risk of injuries and provides for easier assembly of the building blocks and connector element.

The first surface and the second surface are adjacent surfaces in the meaning that the first surface and the second surface share at least one common edge. The first surface may be adjacent to a third surface, and in some types of building blocks the third surface may be adjacent to the second surface. Depending on the shape of the building blocks, some types of building blocks may further comprise a fourth surface, a fifth surface and/or a sixth surface.

The first surface may be perpendicular to the second surface. The first surface may further be perpendicular to the third surface. In some types of building blocks, the third surface may additionally be perpendicular to the second surface.

Any building block of the plurality of building block, e.g. the first building block and/or the second building block may comprise a plurality of recesses, such as further comprising a third recess, a fourth recess etc.

One recess, e.g. the first recess may be contiguous with another recess, e.g. the second recess, thus providing fewer discontinuities along edges of the building block in question. Thus, providing a more clean surface of the building blocks.

Forming any of the recesses, such as the first recess and/or the second recess, on edges between perpendicular surfaces provides for a more stable connection between two building blocks e.g. the first building block and second building block, as the abutting surfaces of the two building blocks abuts an entire surface and not just an edge.

The first surface of each building block may further comprise a third recess extending through the third surface. The third recess may be shaped to allow mating of the first part and the second part, such that when the first part or the second part is inserted in the third recess of the first building block the connector element is restricted from movement relative the first building block in at least a plane parallel to the first surface of the first building block.

Each pair of adjacent surfaces, forming an edge, may provide a pair of recesses comprising the first and the second recess. The pair of recesses provides for a connector element to be inserted such that the connector element is restricted from movement relative to the first building block in a plane parallel to either of the adjacent surfaces of the first building block.

A building block, such as the first building block, may comprise a plurality of pair of recesses. A building block, such as the first building block, may comprise a pair of recesses on each edge, or on each edge between two perpendicular surfaces.

The connector element may have a first connector height. The first connector height may be constant, i.e. the connector element comprises a plane upper surface and an opposite plane lower surface parallel to the upper flat surface. The first connector height may e.g. be in the range of 1 -10 cm, such as in the range of 3-8 cm.

The connector element may have a connector length. The connector length may be in the range of 5-30 cm, such as in the range of 10-20 cm.

The connector element may be made from a hard plastic material. Alternatively the connector element may be made from a foam material, such as EVA foam. The connector element may be made from the same material as the material used for any of the plurality of building blocks. Forming the connector element in a hard plastic material provides a more stabile connection of the building blocks. On the other hand, forming the connector element in a resilient material provides a reduced risk of harm to the users.

The building block system may comprise a plurality of connector elements. Each connector element of the plurality of connector elements may possess the features of the connector element as described. The plurality of connector elements may include a first connector element and a second connector element. The plurality of connector elements may further include a third connector element and/or a fourth connector element.

A primary part of a recess, such as the first recess, the second recess and/or the third recess, may have a depth, such as the first recess having a first depth and the second recess having a second depth. The depth, such as the first depth and/or the second depth may be constant, e.g. a bottom surface of the recess is parallel to the corresponding surface, e.g. the bottom surface of the first recess is parallel to the first surface. The depth may be less than 1/5 of a width of an adjacent surface, such as less than 1/6 of the width of an adjacent surface, such as less than 1/8 of the width of an adjacent surface, e.g. the first depth may be less than 1/5 of a width of the second surface, such as less than 1/6 of the width of the second surface, such as less than 1/8 of the width of the second surface.

Alternatively, the depth of a recess, e.g. the first depth, may be less than 1/5 of a width of any surface of the building block in question, such as less than 1/6 of the width of any surface of the building block in question, such as less than 1/8 of the width of any surface of the building block in question.

Limiting the depth of any recess provides more plane surfaces in general. Specifically, limiting the depth of the first recess, provides for a more clean second surface. The depth, such as the first depth and/or the second depth, may be in the range of 1 -10 cm, such as in the range of 3-8 cm.

A recess, such as the first recess, the second recess and/or the third recess, may have a secondary part proximate to an adjacent surface, e.g. the first recess may have a secondary part proximate the second surface. The secondary part of one recess may extend into the secondary part of another recess, e.g. the secondary part of the first recess may extend into the secondary part of the second recess.

One recess, such as the first recess, may thus be contiguous with another recess, such as the second recess.

The first depth, the second depth and/or the third depth may be substantially similar to the first connector height, such as to provide the upper surface of the connector element to be flush with the first surface, when the connector element is inserted in the first recess.

In a specific embodiment, the first connector height may be twice the depth of a recess, such that it allows forming a connection between more than two building blocks.

The connector elements and the recesses may be constructed such that the second surface of the first building block abut the second surface of the second building block, when the first part of the connector element is mating with the first recess of the first building block and the second part of the connector element is mating with the first recess of the second building block. Thus, providing for easier connecting the building blocks, since the building blocks can be connected by abutting surfaces of building blocks and aligning recesses. Further, allowing the surfaces to abut provides an enhanced stability of the connected building blocks.

The connector element may be designed for easy removal from a recess of a building block. Hence, the first part may comprise a first hole, and/or the second part may comprise a second hole. The first hole and/or the second hole may be dimensioned for a finger, such as big enough that the finger is not stuck in the respective hole and small enough to avoid a hand to fit through or get stuck in the respective hole. The first hole and/or the second hole may comprise a diameter in the range between 1 -10 cm, such as between 2-7 cm, such as between 2-4 cm.

The connector element may comprise at least a first plane of symmetry parallel to a longitudinal axis of the connector element. The connector element may comprise at least a first and a second plane of symmetry parallel to a longitudinal axis of the connector element. Symmetry of the connector element provides several suitable orientations of the connector element when inserted into a recess.

The connector element may further comprise rotational symmetry around a longitudinal axis, i.e. the connector element may comprise an unlimited number of planes of symmetry parallel to a longitudinal axis of the connector element.

A recess may be shaped to perform a transition fit with a part of the connector element, when the part is mating with the recess.

A recess, such as the first recess, the second recess and/or the third recess, may be shaped to perform a transition fit with a part of the connector element, such as the first part and/or the second part of the connector element, when the part is mating with the recess.

The transition fit between the connector element and the recess, is meant in the sense that the connector element is retained inserted in the recess due to frictional forces between walls of the recess and sides of the connector element. However, the transition fit is preferably such that the connector element can be removed from its inserted position in the recess by limited external force.

The transition fit between the connector element and the first recess may be obtained by the connector element having a convex outer shape and/or the first recess having asymmetrical shaped walls, e.g. the first recess may be shaped to have a width proximate to the first surface that is smaller than a width distant from the first surface, wherein the width distant from the first surface is proximate to the bottom of the first recess.

The building block system may further comprise an additional device. The additional device may be an interactive element, such as a tablet computer. The additional device may comprise an audio visual device, thus, the additional device may be able to elicit audio and/or visual information. The interactive element may further comprise a user interface such as a touch sensor, touch screen, a push button, and/or a microphone.

The additional device may add an interactive experience to the building block system, such as to encourage the user to move around in the three dimensional environment. The additional device may be configured to be connectable to a building block, e.g. the first building block, via a fitted connector element. The fitted connector element may be an elongated element, and the fitted connector element may have a first part proximate to a first end of the fitted connector element and a second part proximate to a second end of the fitted connector element. The first part of the fitted connector element may comprise a first protrusion and the second part of the fitted connector element may comprise a second protrusion. Each of the first part and the second part of the fitted connector element may be adapted to mate with the first recess, such that when the first part or the second part of the fitted connector element is inserted in the first recess of the first building block, the additional device is restricted from movement in at least a plane parallel to the first surface of the first building block.

The fitted connector element may be identical to the connector element. Thus, the fitted connector element may comprise all features as described in relation to the connector element.

The fitted connector element may be glued to the additional device. The fitted connector element may be connected to the additional device in a removable way, such as with hoops and loops, magnets or spring locks.

The fitted connector element may be attached to the additional device such that the connector element is rotatable in respect of the additional device.

The fitted connector element may be able to connect two abutting building blocks, similarly as a connector element described earlier, and the fitted connector element may be able to connect the additional device to one or two building blocks.

In some embodiments of the invention, the additional device may be integrated in a building block of the plurality of building blocks, e.g. the first building block and/or the second building block.

The additional device may comprise one or more accelerometers and/or gyroscopes. Thus, the additional device may be able to determine its orientation. The additional device may be able to respond according to its orientation, e.g. the additional device may be able to show visual representation, such as an image, on a screen, and the additional device may be able to orientate the visual representation based on the determined orientation of the additional device.

The word "adjacent" is, throughout this application, used in the sense of two planes sharing at least one common edge, or two shapes sharing at least one common point. The word "contiguous" is, throughout this application, used in the sense of two bodies being connected. A first recess being contiguous with a second recess is to be understood such that the first recess extends into the second recess.

The word "restricted" is, throughout this application, used in the sense of a body not being able to move freely relative to another body. The connector element is restricted from movement relative to a building block in the sense that it is not able to move freely in one or more directions in relation to that building block, when the connector element is inserted into a recess of that building block.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which:

Fig. 1 illustrates an exemplary system comprising a plurality of building blocks,

Fig. 2 illustrates an exemplary building block,

Fig. 3 illustrates an exemplary connector element,

Fig. 4 illustrates an exemplary additional device,

Fig. 5 a, b, c, and d illustrates an exemplary connection of two building blocks with a connector element.

Fig. 6 illustrates an exemplary first connectable position of two building blocks,

Fig. 7 illustrates an exemplary second connectable position of two building blocks,

Fig. 8 illustrates an exemplary third connectable position of two building blocks,

Fig. 9 illustrates an exemplary system comprising a plurality of connected building blocks,

Fig. 10 illustrates an exemplary system comprising a plurality of connected building blocks,

Fig. 1 1 illustrates an exemplary system comprising two groups of connected building blocks,

DETAILED DESCRIPTION The figures are schematic and simplified for clarity, and they merely show details which are essential to the understanding of the invention, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

Fig. 1 illustrates an exemplary system 2 comprising a plurality of building blocks 4. Further the system 2 comprises a connector element 10 and an additional device 12. For the purpose of understanding the three dimensional structure of the illustrated elements, all elements of Fig. 1 are shown in two different perspectives.

The plurality of building blocks 4 shows three different shapes of exemplary building blocks 5, 6, 8, a first type of building block 5 shaped as a rectangular cuboid, a second type of building block 6 shaped as a cylinder, and a third type of building block 8 shaped as a triangular prism.

Throughout the examples these illustrated types of building blocks are referred to. However, it is apparent that the system 2 may comprise further types of building blocks not shown in Fig. 1 , e.g. mats, logs and/or pyramids. Further, it is apparent that system 2 may comprise any number of building blocks 4 of any types 5, 6, 8, any number of connector elements 10, and any number of additional devices 12.

The additional device 12 may be any device capable of reproducing sound and/or visual information. The additional device 12 in this illustrated example is a tablet computer.

A building block 13 with an additional device 14 may be provided, as an alternative or in addition to the additional device 12 having a fitted connector element. The building block 13 comprising an additional device 14 is shown as being a rectangular base building block. However, the building block 13 may be any type of building block, e.g. the first type of building block 5 shaped as a rectangular cuboid, the second type of building block 6 shaped as a cylinder, or the third type of building block 8 shaped as a triangular prism.

Fig. 2 illustrates an exemplary first building block 4. The first building block 4 is of the type of building block shaped as a rectangular cuboid 5. However, the illustrated example could equally be shown for any other type of building block.

The first building block 4 has a building block length L _B , a building block width W _B and a building block height H _B . In alternative exemplary building blocks, the proportions between length L _B , width W _B and height H _B may be different, and in some exemplary building blocks, e.g. cylinders, length L _B and width W _B may be replaced by diameter or radius.

The first building block 4 comprises a first surface 20 and a second surface 22. The first surface 20 and the second surface 22 are adjacent surfaces. Thus, the first surface 20 and the second surface 22 share at least one edge 23. The first building block 4 further comprises a third surface 24 adjacent to the first surface 20. In this example the third surface 24 is also adjacent and perpendicular to the second surface 22.

The first surface 20 comprises a first recess 26, which extends through the second surface 22. The second surface 22 comprises a second recess 27, which extends through the first surface 20. The first recess 26 and the second recess 27 are contiguous, thus, there is an open passage between the first recess 26 and the second recess 27. The first surface 20 further comprises a third recess 28, which extends through the third surface 24.

The exemplary first building block 4 comprises a recess in the center of each edge. The first building block 4, being a rectangular cuboid, comprises 4 recesses on each surface. As seen in this exemplary building block, which may be true for any exemplary building block, all recesses of one surface are contiguous with another recess in another surface. The first recess 26 of the first surface 20 is contiguous with the second recess 27 of the second surface 22, and the third recess 28 of the first surface 20 is contiguous with a fourth recess 29 of the third surface 24.

Each of the recesses has a depth D _R , shown on Fig 5b, e.g. the first recess 26 has a first depth, the second recess 27 has a second depth, and the third recess 28 has a third depth. Preferably the second depth and the third depth are equal to the first depth. Thus, each of the recesses may have the same depth, e.g. the first depth.

Each of the recesses 26, 27, 28, 29 has a first recess width W _{R 1} , and a second recess width WR _,2 . The second recess width W _2, R is less than the first recess width W _{1 R} .

Together with the configuration of the connector element 10, the second recess width W _2, R being less than the first recess width W _{1 R} , means that movement of the connector element 10 is restricted from moving relative to the first building block 4 in a

longitudinal direction of the connector element 10 when inserted in the first recess 26 of the first building block 4. Preferably each of the recesses is identical or has identical dimensions and shapes. Thereby, the connector element 10, shown in Fig. 3, is able to fit any of the recesses, and a single type of connector element 10 is able to connect any two building blocks 4.

Any type of building block, e.g. the first type 5, second type 6 and third type 8 of building blocks, as illustrated in Fig. 1 , comprise similar features as the first building block 4 as illustrated in Fig. 2.

Fig. 3 illustrates an exemplary connector element 10. The connector element 10 is an elongated element, having a first end 31 and a second end 33. The connector element 10 has a first part 30 at the first end 31 of the connector element 10, and a second part 32 at the second end 33 of the connector element 10. The first part 30 comprises a first protrusion 34, and the second part 32 comprises a second protrusion 36. The first part 30 and the second part 32 is connected by an intermediate part 37. The connector element 10 has a first connector width W _{1 C} at the first part 30. Preferably the connector element 10 also has the first connector width W _{1 C} at the second part 32. The connector element 10 has a second connector width W _2, c at the intermediate part 37.

The first part 30 and second part 32 has a larger width W _{1 C} than the intermediate part 32 having a second connector width W _2, c, whereby the first protrusion 34 and second protrusion 36 are formed. Together with the configuration of the recesses, e.g. the first recess 26 and/or second recess 27 (Fig. 2), the second connector width W _2, c being less than the first connector width W _{1 C} , means that the connector element 10 is restricted from movement in the longitudinal direction of the connector element 10 relative to the building block where it is inserted when inserted in a recess of that building block. In an example the the connector element 10 is restricted from

movement in the longitudinal direction of the connector element 10 relative to the first building block 4 when inserted in the first recess 26 of the first building block 4.

The connector element 10 has a connector height, wherein the connector height H _c , shown in Fig. 5, is measured in a direction perpendicular to both a longitudinal direction, i.e. length L _c , of the connector element 10 and a direction of the first protrusion 34, i.e. W _{1 C} . In an exemplary connector element 10 as illustrated the connector height H _c is constant throughout the connector element 10. In an alternative connector element 10, the height H _c may vary e.g. the intermediate part 37 may have a smaller height than the first part 30 and the second part 32.

The first part 30 and/or the second part 32 may be shaped as spheres. Also the intermediate part 37 may be shaped as a cylinder. Hence, a connector element 10 being symmetrical about any longitudinal planes may be obtained, which may ease connection of the connector element 10 to a building block 4, as the connector element 10 will fit a recess in a substantially increased number of possible orientations.

The intermediate part 37 may alternatively be a non rigid structure, e.g. a string or an elastic material.

In the connector element illustrated in Fig. 3, the first part 30 comprises a first hole 38. The second part 32 comprises a second hole 40. The first hole 38 and/or the second hole 40 are through going holes in the direction of the connector height H _c (shown in Fig. 5). The first hole 38 and/or the second hole 40 provides the possibility of easily handling the connector element by providing space for a finger or a hand, dependent on the size of the building blocks 4 and connector element 10 of the building block system 2. Further, through going holes 38, 40 as illustrated on Fig. 2 provide resilience to the first part 30 and second part 32 of the connector element 10. However, the connector element 10 may be formed without through going holes 38, 40, and the resiliency may be obtained otherwise, e.g. by using a resilient material.

The holes 38, 40 may alternatively not be through going, e.g. they may have a depth. As a third alternative, the connector element 10 may have no holes at all.

Referring to Figs. 2 and 3, each of the first part 30 and the second part 32 of the connector element 10 is adapted to mate with a recess of the first building block 4, such as the first recess 26 and/or the second recess 27 and/or the third recess 28 and/or the fourth recess 29.

The connector element 10 is connectable to the first building block 4 by the first part 30 or the second part 32 being inserted in any recess of the first building block 4, such that the connector element 10 extends in a direction parallel to a surface of the first building block 4, such as also indicated in Figs. 5a and 5c. When the connector element 10 is connected to a recess of the first building block 4, the connector element 10 is restricted from movement relative to the first building block 4 in a plane parallel to the corresponding surface. In an example, when the first part 30 or the second part 32 is inserted in the first recess 26, the connector element 10 is restricted from movement relative to the first building block 4 in a plane parallel to the first surface 20. Similarly, the connector element 10 is restricted from movement relative to the first building block 4 in a plane parallel to the second surface 22, when the first part 30 or the second part 32 is inserted in the second recess 27. The connector element 10 is further restricted from movement relative to the first building block 4 in a plane parallel to the first surface 20, if the first part 30 or the second part 32 is inserted in the third recess 28.

Further, the depth D _R of the recess 26, 27, 28, 29 wherein the first part 30 or second part 32 can be inserted, limits movement of the connector element 10 in a direction perpendicular to the surface 20, 22, 24 comprising the recess in question.

The form of the recess and the form of the connector element allow linear displacement of the connector element in only one of potentially six directions, when the first part 30 or second part 32 of the connector element 10 is inserted in any one of the recesses

26, 27, 28, 29.

The first part 30 and the second part 32 are preferably substantially the same shape, or at least identical dimensions. The connector element 10 may be symmetrical about two longitudinal planes. Thus, the connector element 10 may be connected to a recess 26,

27, 28 in several orientations. The first part 30 and the second part 32 may e.g. be identical.

The first depth D _R and the connector height H _c are preferably equal, such that when the connector element 10 is connected to the first recess 26, the connector element 10 is flush with the first surface 20.

Fig. 4 illustrates an exemplary additional device 12. The additional device is here illustrated as comprising an audio visual device 50, such as a tablet computer. The audio visual device 50 is attached to a connector element 10. Thus, the additional device 12 is capable of being connected to a building block, such as the first building block 4. The audio visual device 50 and the connector element 10 may be glued together. The connector element 10 of the additional device 12 further provides the function of a connector element 10 as described in relation to Fig. 3. Thus, the connector element 10 of the additional device 12 provides the possibility of connecting two abutting building blocks in addition to connecting the additional device 12.

Fig. 5 a, b, c, and d illustrates an exemplary connection of a first building block 4 and a second building block 4' with a connector element 10. The first building block 4 is of the type being a rectangular cuboid, also exemplified as 5 in Fig. 1 , and the second building block 4' is of the type being a triangular prism also exemplified as 8 in Fig. 1 .

Fig. 5a illustrates a perspective view of the first building block 4 abutting the second building block 4'. A first recess 26 of the first building block 4 is abutting a first recess 26' of the second building block 4'. The connector element 10 is shown in an orientation capable of being inserted into the first recess 26 of the first building block 4 and the first recess 26' of the second building block 4'. Thus, the connector element 10 is capable of connecting the first building block 4 with the second building block 4'.

Fig. 5b is a cross sectional view of Fig. 5a. Fig. 5b further illustrates that the first recess 26 may be shaped to perform a transition fit with the connector element 10. The transition fit is obtained by providing the first recess 26 with an asymmetrical width along a first direction from the top of the first recess 26, i.e. proximate to the first surface 20, to the bottom of the first recess 26. The first recess 26 comprises a section along the first direction where the width of the first recess 26 is smaller than the width at another sections of the first recess 26. Preferably the smallest width of the first recess 26 is less than the width W _{1 C} of the first part 30 of the connector element 10, and the width of the first recess 26 near the bottom of the first recess 26 is wider or equal to the width W _{1 C} of the first part 30 of the connector element 10. The width of the first recess 26 near to the first surface is wider or equal to the width W _{1 C} of the first part 30 of the connector element 10, such as to ease insertion of the connector element 10. The connector element 10 is further shown having a slight convex shape adding to the performing of a transition fit and the ease of insertion into the first recess 26.

The connector element 10 has a height H _c . The first recess 26 has a depth D _R . The height H _c of the connector element 10 and the depth D _R of the first recess 26 are substantially similar, such that when the connector element 10 is inserted into the first recess 26, as shown in Fig. 5d, the surface of the connector element 10 is flush with the first surface 20 of the first building block 4.

Fig. 5c illustrates a perspective view of the first building block 4 abutting the second building block 4', wherein the connector element 10 is inserted into the first recess 26 of the first building block 4 and the first recess 26' of the second building block 4'.

Fig. 5d is a cross sectional view of Fig. 5c. Fig. 5d further illustrates that the first recess 26 performs a transition fit with the connector element 10, due to the shape of the first recess 26 with a varying width, and the convex form of the connector element 10.

Fig. 6 illustrates an exemplary first connectable position of a first building block 4 and a second building block 4'. The first building block 4 and the second building block 4' being a first type of building block 5 as also illustrated in Fig. 1 .

In the first connectable position of the first building block 4 and the second building block 4', the second surface 22 of the first building block 4 abuts the second surface 22' of the second building block 4'. The first recess 26 of the first building block 4 abuts the first recess 26' of the second building block 4'. The first surface 20 of the first building block 4 is flush with the first surface 20' of the second building block 4'. The first building block 4 can thus be connected with the second building block 4' by applying a connector element 10 (Fig. 3) in the first recess 26 of the first building block 4 and the first recess 26' of the second building block 4'. Thereby, the second building block 4' will be restricted from moving in relation to the first building block 4 in a plane parallel to the first surface 20 of the first building block 4, while the second surface 22 of the first building block 4 abuts the second surface 22' of the second building block 4'. Fig. 7 illustrates an exemplary second connectable position of a first building block 4 and a second building block 4'. The first building block 4 and the second building block 4' being a building block 4 as also illustrated in Fig. 2.

In the second connectable position of the first building block 4 and the second building block 4', the first surface 20 of the first building block 4 abuts the first surface 20' of the second building block 4'. The second recess 27 of the first building block 4 abuts the second recess 27' of the second building block 4'. The second surface 22 of the first building block 4 is flush with the second surface 22' of the second building block 4'. The first building block 4 is thus connectable with the second building block 4' by applying a connector element 10 (Fig. 3) in the second recess 27 of the first building block 4 and the second recess 27' of the second building block 4'. Thereby, the second building block 4' will be restricted from moving in relation to the first building block 4 in a plane parallel to the second surface 22 of the first building block 4, while the first surface 20 of the first building block 4 abuts the first surface 20' of the second building block 4'.

Fig. 8 illustrates an exemplary third connectable position of a first building block 4 and a second building block 4'. The first building block 4 and the second building block 4' being a building block 4 as also illustrated in Fig. 2.

In the third connectable position of the first building block 4 and the second building block 4', the third surface 24 of the first building block 4 abuts the third surface 24' of the second building block 4'. The third recess 28 of the first building block 4 abuts the third recess 28' of the second building block 4'. The first surface 20 of the first building block 4 is flush with the first surface 20' of the second building block 4'. The first building block 4 can thus be connected with the second building block 4' by applying a connector element 10 (Fig. 3) in the third recess 28 of the first building block 4 and the third recess 28' of the second building block 4'. Thereby, the second building block 4' will be restricted from moving in relation to the first building block 4 in a plane parallel to the first surface 20 of the first building block 4, while the third surface 24 of the first building block 4 abuts the third surface 24' of the second building block 4'.

Fig. 9 illustrates an exemplary system 2 comprising a plurality of connected building blocks 4 forming a first group 60. The exemplary system 2 comprises a plurality of rectangular building blocks 5, 5', a plurality of cylindrical building blocks 6, 6', a triangular building block 8, a plurality of connector elements 10, 10', 10", and a first additional device 12.

The system 2 may optionally comprise any number of building blocks and any number of different types of building blocks. The system 2 may comprise a plurality of rectangular building blocks 5, 5', including a first rectangular building block 5 and a second rectangular building block 5'. The system 2 may comprise a plurality of cylindrical building blocks 6, 6', including a first cylindrical building block 6 and a second cylindrical building block 6'. The system 2 may comprise a plurality of triangular building blocks 8, including a first triangular building block 8 and a second triangular building block (not shown).

The system 2 may optionally comprise any number of additional devices 12, e.g. the system 2 may comprise a plurality of additional devices 12 including a first additional device 12, and a second additional device (not shown).

The system 2 may comprise any number of connector element 10, 10', 10", e.g. the system 2 may comprise a plurality of connector element 10, 10', 10" including a first connector element 10, a second connector element 10' and optionally a third connector element 10".

The system 2 comprises the plurality of building blocks 4, the first additional device 12 and the plurality of connector elements 10, 10', 10" being connected together to form a single first group 60.

The first cylindrical building block 6 is connected with the first rectangular building block 5 by a connector element attached to the first additional device 12. The first rectangular building block 5 is further connected to the second cylindrical building block 6' by the first connector element 10. The second cylindrical building block 6' is further connected to the first triangular building block 8 by the second connector element 10', and connected to the second rectangular building block 5' by the third connector element 10". The first additional device 12 is located such that a child is able to operate it. Due to the connector element attached to the first additional device 12, the position of the first additional device 12 can be changed, such that it can be placed at a position of another recess. The first additional device 12 is shown as being placed in a position where two building blocks 5, 6 abut. However, the first additional device 12 could be placed in a position where only the first or the second part of the connector element mates with a recess, and thus, the first additional device 12 may be connected to a single building block.

Fig. 10 illustrates an exemplary system 2 comprising a plurality of connected building blocks 4 forming a second group 62. The exemplary system 2 comprises a plurality of rectangular building blocks 5, a plurality of cylindrical building blocks 6, a plurality of triangular building blocks 8, a plurality of connector elements 10, and a second additional device 12'. The system 2 as illustrated in Fig. 10 comprises the plurality of building blocks 4, the second additional device 12' and the plurality of connector elements 10 being connected together to form a single second group 62. It is emphasized in Fig. 10 that the plurality of building blocks 4 are interconnectable to build a three dimensional second group 62.

The second additional device 12' is located such that a user, e.g. a child, may need to climb or stretch upwards to be able to operate it. Further, the constructed structure of the system 2 possess obstacles for the user, such that the user is forced to move around or over some of the plurality of building blocks 4 in order to reach and/or operate the second additional device 12'.

Fig. 1 1 schematically illustrates an exemplary system 2 comprising the first group 60 and the second group 62 of connected building blocks 4. The first group 60 is the first group 60 as explained in relation to Fig. 9, and the second group 62 is the second group 62 as explained in relation to Fig. 10. In combination, the first group 60 and the second group 62 forms the system 2 comprising the first additional device 12 and the second additional device 12'. It is seen that the user is prompted to move to get from a first operating position of the first additional device 12 to a second operating position of the second additional device 12'. The first group 60 and the second group 62 is capable of being separated further away from each other, or obstacles of building blocks 4 can be positioned between the two groups 60, 62, such that the user needs to climb over, walk around, or climb around, to get from the first operating position to the second operating position. The system 2 may be configured to elicit a first audible and/or visual information in the first additional device 12, to receive a user input e.g. a touch of a touch screen or a button in the first additional device 12, and to elicit a second audible and/or visual information in the second additional device 12'. The user may thus be stimulated to move to the first additional device 12 and perform a desired task, e.g. touch the screen, and afterwards be prompted to move to the second additional device 12'. By positioning the plurality of additional devices 12, 12' such that the user is challenged to e.g. climb over objects, or build objects to reach the additional device 12, 12', the user is developing his/hers motor- and cognitive skills.

The system 2 may be extended to include a further number of additional devices, such as a third additional device and/or a fourth additional device.

Although the teaching of this application has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the teaching of this application.

It should also be noted that there are many alternative ways of implementing the teaching of this invention, and elements of above examples may be interchanged. The above listed examples are therefore not to be seen as an exhaustive list of

embodiments of the invention.

The term "comprising" as used in the claims and above does not exclude other elements or steps. The term "a" or "an" as used in the claims does not exclude a plurality. A "first" is not a prerequisite of a "second" and/or a "third", but merely describes denomination of an entity.

LIST OF REFERENCES

2 building block system

4, 4' building block

5, 5' first type of building block

6, 6' second type of building block

8, 8' third type of building block

10, 10', 10" connector element

12, 12' additional device

13 building block with an additional device 14 additional device of a building block

20 first surface

22 second surface

23 edge

24 third surface

26, 26' first recess

27 second recess

28 third recess

29 fourth recess

30 first part of connector element 31 first end of connector element

32 second part of connector element

33 first end of connector element

34 first protrusion

36 second protrusion

37 intermediate part of connector element

38 first hole

40 second hole 50 audio visual device

60 first group

62 second group

H _B building block height

WB building block width

LB building block length

He connector height w _1iC first connector width

W ₂ ,c second connector width

Lc connector length

DR recess depth

W _{1 IR} first recess width

W _2, R second recess width