The subject of this invention is a bottle cap-building block which can be used as a toy for children and which is applied for closing containers, especially bottles, intended for storing food products, such as mineral water, beverages, nectars, juices, dairy products and milk. The cap being the subject of this invention can be used in various types of packaging, such as PET, HDPE as well as cardboard packaging. It is also possible to use this cap for closing non-toxic hygienic products, such as, for example, toothpaste packaging.

There are the solutions of caps which are simultaneously the building blocks intended for playing.

The solution titled: "Combination bottle cap and construction toy" is known from an American description of invention (publication number US5361919A). The revealed invention is a combination of bottle cap and construction toy, which allows for joining collected caps together, using them to build figures of various shapes and in various configurations. The caps described therein are encased in a hexagonal solid, with protrusions on its sides, or more precisely, there is a protrusion on every second side, and there is a recess corresponding to this protrusion on the next side. Additionally, the circumferential edges of caps - both the lower and the upper ones - are bevelled and there are also the recesses or protrusions corresponding to the recesses made in them, allowing to fasten the other caps together, at an angle of 45°. Similar protrusions are made also in the bottom of the cap, on its external surface. The construction of caps allows fastening them together.

The solution titled "Essentially cylindrical functional cap shaped as a building block, use of the cap, method for producing the cap, and set of at least one cap" is known from another Brazilian description of invention no. BR20141003102 (there is no publication number for this invention). This invention regards an essentially cylindricaily shaped cap, which has a side wall with internal and external parts and is fitted with an element for fixing a lockable cover to the container. Its upper surface - with interna! part and external parts - has at least one pin as a connecting element and/or the socket as a connecting element and/or a number of elements which block the connection in at least one of its surfaces. The base of the attachment is not fitted with a socket and a mounting element protruding outside the external part of the side wall. The attachment contains an element which facilitates positioning the cap for mounting and this element is selected from a group consisting of (in various caps): protrusion, recess or combination of them. This invention regards also the applications and processes for producing the caps and the sets containing such caps. Another solution, titled "Building block type bottle cover" is known from a Chinese description of utility model, no. CN20032127139U. The utility model is a bottle cover, in particular a bottle with a building block type cover, which is intended for increasing the interest in bottle closure. According to the utility mode! the bottle cap is a round box. It is equipped with a socket or plug -therefore the bottle covers can be joined together, in order to form various shapes, by connecting the plugs with the sockets.

Another solution, titled: "Bottle cap building block", is known from an Australian invention, no. AU2000PQ00088. The bottle cap presented therein can be used also as a toy. The attachment contains an upper surface with a number of incisions, which have such shape and size so that they fit in at least one path or groove spreading out across the lower surface of the other cap's edge. The path width and the incisions made in it are identical or slightly smaller than the width of cap periphery. It is possible to place several caps on one attachment in an association system, allowing to use them as building elements. Essentially there are many protrusions, marking out a number of various paths, so the attachment protection can simultaneously join several other caps together with one connection.

Another solution, titled "Combined packaging and plaything", is known from an English invention, no. GB19930003848. The head presented therein resembles a lollipop and it is placed in packaging (essentially in the form of a cube) and is fitted with uniform, triangular splines or sockets. The sockets can be snap fastened to other similar sockets and in this manner the packaging can form a constructional part of a toy. The head of the lollipop can contain an extended stick, folded telescopically, in such a manner that it can be almost entirely inserted into the head. In such case the entirety can be housed in essentially cubical solid.

The purpose of developed invention is creating such a cap which could be used also as a building block for building various three-dimensional constructions. The purpose of this invention is also the utilization of waste which is generated during the production of packaging and caps and can be used as simple toys for children.

The essence of the developed cap-building block, in which the splines and sockets are made, consists in the fact that it is a two-sided cap-building block, which consists of a cylindrical body, on one side closed by the upper surface with, in total, four splines and sockets arranged radially and alternately on the body perimeter, on its side wall, where the splines and sockets are arranged, most favourably, in such a manner that the spline, located exactly on the opposite body side, in a straight line, corresponds to the spline, and the socket corresponds to the socket, and the size of these elements was selected in such a manner that the spline fits in the socket.

Favourably, there is a spline on the upper surface, on the external side of the two-sided cap-building block, and the socket is placed on the upper side of the two-sided version of cap-building block, and additionally the spline or the socket is made on their internal side. Favourably, both the splines and sockets have the shape of cylinder in their essential part and they are round in the cross-section, and the cross-section of their outermost parts has the shape of circle in case of the spline and the shape of ring in case of the socket.

Favourably, the splines and the sockets are made of the same material as the body.

The cap-building block, in which the splines and sockets are made, can be also a many-sided cap-building block, consisting of a cylindrical body, on one side closed by the upper surface with a number of splines and sockets (most favourably eight in total) arranged radially and alternately on the body perimeter, on its side wall, which are arranged, most favourably, in such a manner that the spline, located exactly on the opposite body side, in a straight line, corresponds to the spline, and the socket corresponds to the socket, and the size of these elements was selected in such a manner that the spline fits in the socket.

Favourably, the spline is located on the upper surface, on the external side of the many-sided cap-building block, and the socket is located on the upper surface of the many-sided version of the cap-building block, and additionally the spline or the socket is made on their internal side.

Favourably, both the splines and the sockets have the shape of cylinder in their essential part and they are round in the cross-section, and the cross-section of their outermost parts has the shape of circle in case of the spiine and the shape of ring in case of the socket.

Favourably, the splines and the sockets are made of the same material as the body.

The solution according to the invention allows applying waste generated in the production of packaging and using it as toys for children. Thus the solution encourages to sorting and collecting such waste as the caps, which are used in this case for education and play for children. Then they can be easily recycled later because they are already cleaned and collected in greater amount.

The invention allows building three-dimensional constructions, similar to and equally nice and complicated as the constructions built of building blocks in strict sense, using the caps intended for packaging closing. The developed cap allows also connecting the cap-building blocks constituting the subject of the invention with the building blocks known and available on the market.

The subject of the invention is presented closer in an embodiment shown in the figures, where fig. 1 presents the axonometric projection of the first type of the cap-building block, i.e. the two-sided cap-building block with the spline on the upper surface and with the spline shown from the front, fig. 2 presents the axonometric projection of the two-sided cap-building block with the socket on the upper surface, rotated by 90° and with the socket shown from the front, fig. 3 presents the axonometric projection of the first type of the cap-building block, i.e. the two-sided cap-building block with the spline on the upper surface and with the socket shown from the front, fig. 4 presents the axonometric projection of the two-sided cap-building block with the socket on the upper surface, rotated by 90° and with the spline shown from the front, fig. 5 presents the axonometric projection of the second type of the cap-building block, i.e. the many-sided cap-building block with the spline on the upper surface and with the socket shown from the front and with the splines on its both sides, fig. 6 presents the axonometric projection of the two-sided cap-building block with the socket on the upper surface, rotated by 90° and with the spline shown from the front and with the sockets on its both sides.

As it is shown in figures, the subject of the invention are alternative sets of caps-building blocks, where the first set consists of two-sided caps-building blocks (1) (figures 1 to 4), and the second set consists of many-sided caps-building blocks (2) (figures 5 to 7).

Both the two-sided caps-building blocks (1), and the many-sided caps-building blocks (2) are made in a variant with the spline (3) on their upper surface (4) - in case of caps-building blocks (1), this version of the invention is illustrated in fig. 1 and fig. 3, and in case of many-sided caps-building blocks (2) this version of the invention is illustrated in fig. 5, as well as in a variant with the socket (5) on their upper surface (4) - in case of caps-building blocks ( ) this version of the invention is illustrated in fig. 2 and fig. 4, and in case of many-sided caps-building blocks (2') this version of the invention is illustrated in fig. 6.

As it is shown in figures, both the two-sided cap-building block (1) and the many-sided cap-building block (2) consist essentially of the body (6), which is a cylinder, favourably made of plastic, where the parameters of the body, such as: height, radius, extrusion depth and thickness of side walls depend on the type of packaging to which the two-sided cap-building block (1) or the many-sided cap-building block (2) will be adapted. In the body (6), the splines (3) or the sockets (5) on its upper surface (4) are made of the same material as the body (6).

The splines (3) and the sockets (5) are placed on the body (6), contiguously to its side walls and they are arranged radially and alternately on them, in a number of at least four - in two-sided cap-building block (1), or in greater number, most favourably eight - in many-sided cap-building block (2).

The splines (3) and the sockets (5) are placed in pairs, most favourably in such a manner that if the spline (3) or the socket (5) is located on the body (6) in a given place, then the corresponding socket (5) or spline (3) is located exactly on the opposite side, in a straight line of the body (6) and thus the splines (3) and the sockets (5) form the pairs corresponding to each other.

Most favourably, both the splines (3) and the sockets (5) have, in their essential part, the shape of cylinder and they are round in the cross-section, and the cross-section of their outermost parts has the shape of circle in case of the splines (3) and the shape of ring in case of the sockets (5).

The size of these elements was selected in such a manner that the spline (3) fits in the socket (5). These elements can be cylindrical, but also cuboidal, with any base, e.g. triangle, square, trapezoid, rectangle, but they always correspond to each other with their size. In case when they are cylindrical, the radius of the spline (3) is equal to the internal radius of the socket (5). Thanks to that when the caps-building blocks are joined together, the friction force is sufficient to ensure a rigid connection of these elements, which allows building various three-dimensional constructions of them. However, the connection of these elements is simultaneously weak enough that each user, including a child, can easily disconnect the two-sided caps-building blocks (1) or many-sided caps-building blocks (2).

The body (6) with the upper surface (4) closes the packaging, which is, e.g., a bottle.

The spline (3) or the socket (5), depending on the cap type, is made in the upper surface (4) of the cap, on its internal side, which is exposed to contact with the content of packaging. The socket (5) or the spline (3) is made also in the upper surface (4), on its external side, i.e. this side which is located on the packaging top and is not exposed to contact with the content of packaging.

Thus, depending on the cap type, if the socket (5) is made in the internal part of the cap, in the upper surface (4), then the spline (3) is made on the external, upper surface {4}. And vice versa, if the spline (3) is made in the internal part of the cap, in the upper surface (4), then the socket (5) is made, in this case, in the upper surface (4), on its internal part.

The caps-building blocks constructed in this manner allow joining them together not only in two, but also in three dimensions, building three-dimensional constructions serving to children and developing their imagination, inventiveness and sense of space.

List of elements:

1. two-sided cap-building block,

2. many-sided cap-bui!ding block,

3. spline,

4. upper surface,

5. socket,

6. body.