Modular units are widely used in structural engineering.

Swiss patent application P 329326 in Polish Patent Office regards a building module designed for building flat structures, walls in particular. The said module has two parallel wall parts with shapes of boards, external surfaces of which make a surface layer of erected wall. A core of the module, made of wood, couples both wall parts together and contains at least one part run in longitudinal direction of the module, which, when setting the next building module, enters in the vertical direction between the wall parts of the next module and together with it forms a plug joint which intercepts forces acting in transversal direction.

Another building module is known from patent application P 336370 in Polish Patent Office. This module designed for erecting, in particular, wall frames contains carrying posts coupled together with spacing boards containing edges introduced into these posts, with extreme posts containing, from lateral sides, coupling wings with lengths equal to, after coupling has been made, the distance between adjacent carrying posts. From front side the carrying posts are equipped with peg joints with seats and pegs, designed for coupling with adjacent modules. The spacing boards are situated in the central part along one preferably vertical plane of symmetry or near external edges of the posts alternately along parallel planes. With the alternate placement of the spacing boards there are vertical grooves in the carrying posts designed for fixing board covers making through-channels together with other elements.

The patent application P 333994 in Polish Patent Office describes wall building unit containing a corner hollow tile which cooperates with basic hollow tiles. The corner tile contains a longitudinal square hollow situated inside a square jacket, in an upper right corner being square halvings equipped with longitudinal grooves with the shape of letter"u", whereas the length of side of the square halving is equal to half the length of external side"b"of the square jacket. The basic hollow tile with the shape of flattened letter"z"contains a longitudinal square hollow situated inside a longitudinal square jacket, with square halvings lying at diagonal lines of the hollow, equipped with longitudinal grooves with the shape of letter"u", whereas the length of side"a"of the square halving is equal to half the length of external side"b"of the square jacket.

The building modules described above are designed especially for erecting walls, whereas the patent application P 302089 in Polish Patent Office describes building unit of self-supporting light ceiling between storeys or under the roof.

This unit has a form of cuboidal block with at least two hollows along the whole length. On its whole length the unit contains lower ledge/groove and upper ledge/groove matching each other and situated alterrnately. On its upper surface the unit can contain at least one groove and at least one ledge situated perpendicularly to longer axis of the unit. Such construction of the building unit makes it possible to mount large surfaces quickly and easily, with good thermal characteristics, tight-fitting and, simultaneously, suitable for fixing roofing elements on them.

The aim of the present invention is such shape of a modular building unit which preserves advantages of structures known up to the present and makes it possible to obtain versatility consisting in possibility of using the said unit for erecting both walls and slab ceilings and making corners of buildings without any additional units.

The essence of the present invention consists in that at one corner of the cross-section of a cuboidal unit there is a rounded off protrusion turned towards the longitudinal axis of cross-section of the unit, whereas at the corner lying at the opposite side of diagonal line of cross-section of the unit there is a second protrusion turned towards the opposite side in relation to the first protrusion and bent outside in direction consistent with the longitudinal axis of the unit, between each protrusion and a body of the cross-section being the recesses, each with shape corresponding to the shape of the protrusion lying at the opposite side of cross-section of the unit. In the center of the cross-section there is a hole.

Due to original shape of the invented unit it is possible to erect building structures of many purposes, both one-and multi-storey ones, on both open and closed plan. As opposed to the units known up to the present, the same unit is used for erecting walls and making slab ceilings and, furthermore, makes it possible to simplify linted and window beams. Essential advantage of the module is possibility of dividing it and using the same kind of module for building various kinds of corners. Apart from its versatility the unit is characterized by easiness of prefabrication and on site fitting-up without usage of specialistic equipment, lightness of construction, very good thermal, acoustic and fire- extinguishing insulation, possibility of making constructional carrying posts in case of vertical wall units or constructional carrying beams in a case of horizontal ceiling units, as well as possibility of obtaining mounting, electrical and ventilating ducts without necessity of making special elements.

The invention will be presented on exemplary realization shown in attached figures, on each of the figures the modular building unit being shown in top view. Fig. 1 shows a single unit, fig. 2-two units after coupling them together, fig. 3-the unit with line of intersection passing through its center and being the secant of right angle whose one arm coincides with longer side of the unit, fig. 4-the same unit in which the line of intersection is perpendicular to the line of intersection shown in fig. 3, fig. 5, fig. 6, fig. 7, fig. 8, fig. 9, fig. 10, fig.

11 and fig. 12 show various possible corners of buildings, made of various combinations of parts of the unit obtained by cutting the unit in accordance with lines shown in fig. 3 or fig. 4 and by turning some of the parts upside down in order to obtain mirror reflection of the shape.

The modular building unit has a form of cuboid with optimum height of approximately 2.5 m, with cross-section, invariable along the whole height of the unit, approximating a rectangle in general outline. At one corner of the cross- section there is a rounded off protrusion 1 turned towards the longitudinal axis of cross-section of the unit, whereas at the corner lying at the opposite side of diagonal line of cross-section of the unit there is a second protrusion 2 turned towards the opposite side in relation to the first protrusion 1 and bent outside in direction consistent with the longitudinal axis of the unit. Between each protrusion 1 and 2 and a body of the cross-section there are recesses 3 and 4.

Shape of each of the recesses 3 and 4 corresponds to the shape of the protrusion 1 or 2 lying at the opposite side of cross-section of the unit, that is the recess 3 corresponds to the protrusion 2 and the recess 4 corresponds to the protrusion 1.

In the center of the cross-section there is a hole 5. In the presented example, overall dimensions of cross-section of the unit are equal to 0.9 m x 0.3 m which, at optimum height of the unit of 2.5 m, makes it possible to erect buildings without usage of specialistic equipment.

When the first unit has been fixed on site, the next identical unit is added as shown in fig. 2. Insertion of the protrusion 2 of the added unit into the recess 3 of already fixed unit is easy due to presence of mounting slots 6, which are filled with a construction mass such as concrete mix, in further stages of erection. The holes 5 in the units are filled with a construction mass such as concrete mix, with steel reinforcing rods or reinforcing glass fibers if need be. Thus a durable coupling of joined units is obtained. The construction mass fills the whole height of the unit creating a vertical post which increases its height during the same operations when erecting units of higher storeys. In case of slab ceilings, filling the holes 5 with a construction mass creates a horizontal carrying beam.

It is advisable to let some holes 5 remain empty. The empty holes can be used as ventilating ducts and ducts conducting media necessary in the building.

Such solution eliminates the necessity of making special units, thus reducing erection costs. The same is the purpose of holes and recesses in elements accordant to the present invention, used for making slab ceilings.

Due to the fact that the line of intersection 7 of cross-section of the unit shown in fig. 3 and the line of intersection 8 shown in fig. 4 divide the basic unit to smaller pieces it is possible to obtain various corners of erected buildings while preserving right angle. Exemplary shapes of these corners, which can be used according to needs, are shown in fig. 5, fig. 6, fig. 7, fig. 8, fig. 9, fig. 10, fig. 11 and fig. 12.

Of course, overall dimensions of the invented modular building unit can vary according to needs and kind of material used for its production.