WO2014187434A1

WO2014187434A1 - Prefabricated floor and method of its production

Info

Publication number: WO2014187434A1
Application number: PCT/CZ2014/000053
Authority: WO
Inventors: Radovan Vojtasík
Original assignee: Radovan Vojtasík
Priority date: 2013-05-20
Filing date: 2014-05-14
Publication date: 2014-11-27
Also published as: CZ2013364A3; SK50092014U1; SK7023Y1

Abstract

Floor elements (1, 2, 3) contain connecting cavities (4) running past their face surface from one lateral side to the other. The elements (1, 2, 3) are interconnected with the fastener (5) for fixed coupling with a mandrel, one part of which is fixed in the connecting cavity (4) of the first element (1) and the other part in the body of the adjacent second element (2). The connecting cavities (4) have preferably different diameters, larger diameter for head (6) and smaller diameter for mandrel. Optionally a groove (7) for placing of heads (6) is contained. The connecting cavities (4) are hollowed in the elements (1, 2, 3) in a row with regular distances. Floating floor is produced by means of placing elements (1, 2, 3) to each other and embedding mandrels through the connecting cavities (4). Fixation through the connecting cavities (4) is preferably combined with fixation with locks.

Description

Prefabricated floor and method of its production. Technical Field The invention relates to a floor prefabricated of elements such as floating floor, overlay flooring, and industrial slab floor. A new structural design of floor elements and floors made of them is designed, and also the method of production of prefabricated floor using the designed structural solution of floors is designed. Background Art

The classic type of floor is a floor of simple wooden boards and a tongue and groove. Simple boards represent the solution of floors in which the boards are juxtaposed on a subfloor and fixed directly to the subfloor using screws or nails passing through said boards in the direction from top downwards. Fastening means, typically screws or nails, are placed in the height direction vertically through a face and the heads of nails or screws remain on the face side of the boards. Laying is simple, by sequential laying on the place and nailing or screwing in of screws, optionally with pre-drilling of holes.

In the case of tongue and groove, the structural design to strengthen the joint and to limit gaps is used, in which a groove is created on the lateral side of each board in the longitudinal direction and a longitudinal jutting, a tongue, is formed on the corresponding lateral side of the adjoining board being attached at the side. The making procedure is also very simple. One board is laid next to the other on a sub-floor in the form of a flat background or a bearing structure and in so doing the tongue is inserted into the groove, after which the board is nailed or screw onto the sub-floor perpendicularly across the face side of the board or optionally diagonally across the tongue at the site of joint.

The great disadvantage of the abovementioned flooring types is the fact that the flooring material cannot work during the drying of material, temperature changes, or humidity changes. Individual boards are firmly attached to the sub-floor and cannot move as needed during dilatation, which results in the formation of undesirable gaps and cracks in the floor, or alternatively bulges on the finished floor. Another disadvantage of these floors is the unsightliness caused by clearly visible heads of screws or nails, which is unacceptable in a modern interior nowadays.

Another type of flooring nowadays widely used is the so-called floating floor. These are floors assembled from elements as planar formations, in which the individual elements are attached to each other and interlocked using different types of locks. A joint whole is gradually created with the help of placing individual elements to each other while pressing the interlocking locks together. Making such floor is very easy. Just adjust the length of the elements and upon placing and pressing, the elements already snap together by themselves. Free expansion gap that is visually covered with a baseboard is left on the edges of the room. In this case, nothing prevents displacement of individual elements on the subfloor. Working of material and its dilatation is manifested only by increasing or reducing the free edges of the fabricated surface during the first years of the floor service. Typically, a change takes place several times during a calendar year, and therefore these floorings are also called floating floors. Fasteners, click-locks, consist in a dovetail or otherwise interlocking shaping of the element side walls. Nowadays, there are many types of these locks already on the market.

For example CZ U 16645 describes the wooden constructional floating floor from boards with tongue and groove of the interlocking type. The tongue of said boards has a horizontal upper surface and the lower surface of the tongue forms an angle with the upper surface of 13 to 17 angular degrees. The thickness of the tongue at its base is 40 to 50 % of the board thickness and the length of the tongue on its upper surface is 65 to 80% of the board thickness. Simultaneously, the upper straight arm of the groove has a thickness of 25 to 35 % of the board thickness.

Another example of floating floor is described in EP 1 350 904 B2. It describes a profile for perpendicular connection of at least two floor elements along a perpendicular movement plane, which are provided with an upper side, a lower side, two longitudinal sides and two front sides, while the profile has a groove on the one hand, a tongue on the other hand, as well as corresponding locking elements arranged on the groove and on the tongue that hold at least two floor elements being connected in their vertical association. Floating floors with locks have the disadvantage that a local gaping of individual elements occurs with time, which results in formation of unsightly gaps or cracking of connecting locks. This is due to the fact that when covered by furniture and other load and/or in the case of large floor area, the shift of individual elements on the subfloor is limited and unequal. In such case, local gaping of the joint or rupture of the joint is easier for the floor than "floating". These drawbacks are especially exhibited in the case of wooden floors, which are however significantly more expensive than laminate, chipboard and other artificial materials. Wood is natural material, however, and it has many other benefits such as air permeability, beautiful appearance, etc., so that it is considered to be the best quality and therefore hypothetical^ most desirable material.

Other known joints of floor elements such as glued joints, the joints using inserted dowels, joints using inserted decorative distance layer, etc. have the same disadvantages.

Disclosure of Invention

The above-mentioned disadvantages are eliminated by the invention. A new structural design and a method of production of prefabricated floor of the type of planar formation created by the layer of flat elements placed next to each other, each having a face surface and a reverse surface, is designed. The essence of the new structural design of this floor is in that at least some elements have in them created at least one connecting cavity running out-of the face surface of the element at variable or constant distance to its face surface from one side to the opposite side, i.e. through the whole element, in the direction of the line pointing to the adjacent element. Adjacent elements are interconnected with the help of at least one fastener for fixed coupling with a mandrel, one part of which is located in the connecting cavity of the first element and the other part protrudes from the connecting cavity into the body of the other adjacent element where it is firmly fixed.

The connecting cavity according to the invention is either in the form of opening in the element or in the form of groove realised as a recess in the reverse side of the element. The connecting cavity has preferably at least two different diameters, of which the bigger diameter is for passage of the head of the fastener for fixed coupling with a head, for example for the head of a screw, and the smaller diameter is for the mandrel of said fastener, for example for the screw stem. Using of screws as fasteners is not a condition. Alternatively, for example anchors or dowel pins with screw, nails or similar means for nailing, driving, or shotfired fixing, two-piece connecting bolts with various types of nuts such as connecting bolts with furniture nut, anchors etc. can be used.

The connecting cavity runs through the whole element from one side to the opposite side. It can run at a small slope, for example at a small downward slope for reasons of easier assembly. Preferably for easier production and elimination of the risk of unwanted cracking during assembly or because of high load on the floor, the connecting cavity runs parallel with the plane of the element face surface.

With the advantage of easy assembly, the connecting cavity is produced running across the element in its transversal direction.

Countersinking of the head of said fastener can be preferably solved according to the invention in the following way. At least one of the pair of interconnected elements can be at least on its part of the side with the connecting cavity or cavities intended for the entry of mandrel of the said fastener preferably equipped with at least one groove running on it in a longitudinal direction and adapted for the head of said fastener. This means preferably containing a gap between the walls of the groove recess of a size larger than the head of said fastener. Then at least one connecting cavity made in this element runs from this groove.

At least one element contains preferably at least two connecting cavities.

At least one element contains preferably at least three connecting cavities that are running on it parallel to each other in regular distances.

The constructional system according to the designed solution is preferably combined with modern types of floating floors having created so called locks. Adjacent elements have besides the interconnection with the help of connecting cavities and fasteners according to the invention additionally also mutually engaging shape of the type where one element has created at least one connecting projection and the other element has created at least one connecting recess for this projection, both in the form of means for ensuring precise relative position in the connected state.

Method of production of prefabricated floor with utilisation of the structural design according to the invention is intended for floors of the type in which the final floor is created as a layer from elements by their sequential laying next to each other on the place of destination and fixing. It is especially suitable for floating floors, overlay flooring, or industrial floors from single-layer or multilayer boards consisting of one or more materials. According to the designed method at least some elements are fixed to their place by means of creation of connecting cavities and subsequent fixing to the place of destination with the help of sticking in fasteners for fixed coupling through the connecting cavities created in this way. However, according to the invention, this is not done with openings from above to bottom and with fastening to the subfloor, as it is done at background art, but it is done as construction of floating floor, that is by construction of a layer from elements that do not need to be fastened towards the subfloor in any way. This is achieved so that at least some elements are pre-fitted with connecting cavities passing across the whole element in the direction skew towards the face surface of the element from one side of the element to the opposite side in the direction towards the adjacent floor element to which the said element being connected should be fastened, taken according to the position of the elements in completed floor. The floor is then made so that the element being connected is placed to the other element already laid on the place of destination, the fastener for fixed coupling comprising a mandrel is placed into the connecting cavity, the end of this fastener is embedded through the connecting cavity into the body of the adjacent element and firmly fixed here, but at the same time at least part of the mandrel is left in the connecting cavity of the element being connected where the opposite end of the fastener is also firmly fixed. During this whole process of laying the floor, each insertion and fixing of the fastener is done out of the face side of the element being connected as well as the element already laid on the place of destination.

In the case where easiness of assembly is preferred, the connecting cavities are hollowed into the elements in a minute to gentle slope towards the face surface. With the advantage of easy manufacture of connecting cavities, the connecting cavities are hollowed in parallel with the face surface of the element, and that is done either by drilling through the elements while creating openings or by milling from the reverse side of the elements to cerate grooves.

Preferably at least one section of the connecting cavity is made with a diameter larger than that of another section of the same connecting cavity, and then during laying the floor, the drilled-through element is placed with the orifice of the narrower part of the connecting cavity to another already laid element, and the fastener with head is placed, mandrel first, into the connecting cavity via the broader part of the connecting cavity, and that is done up to stop in the optimal case. That is, the fastener is placed in the connecting cavity preferably so far that its head is leaning against the place of narrowing of the connecting cavity. In doing so, of course, the fasteners of such length should be used so that the end of the fastener mandrel is embedded into the body of the adjacent already laid down element. This solution prevents cracking of elements in the case of embedding screws or other fasteners with a head. High strength and service life of the joint is achieved in the case when the fastener is embedded all the way to the narrowing.

The element with the connecting cavity is laid to another already laid down element preferably so that the connecting cavity leads to an integral part of the side wall of the element already laid down. However this is not an unconditional requirement, for example in the case of using connecting bolts with recessed nut, it is possible to interconnect the elements through continuously linked-up connecting cavities as described also in one of the examples of embodiments hereinafter.

Different or all connecting cavities in the elements have preferably identical dimensions, however, fasteners of various lengths can preferably be placed on purpose into various connecting cavities. This option can be utilised especially in the case of installation of floors from solid timber, that is natural wood, and the length of the fasteners can be selected so that they will not reach into knots or other problematic areas in material.

The connecting cavities are preferably hollowed in the direction of width of the elements, in a row in which the connecting cavities are located in regular spacing while the distance of the end connecting cavities from the element ends is selected so that in the case when the elements are adjoined linked-up in the length direction, the resulting spacing between the end connecting cavities of adjoined elements is the same as the spacing between the neighbouring connecting cavities in the row.

In addition to the connecting cavities, also locks based on projections on one element and a corresponding recess in the neighbouring element, as in the case of modern floating floors for example of the type of tongue and groove or dovetail latch, are preferably made on all elements, and then during production of the floor, the adjacent elements are interconnected first with the help of these locks and after that also with the help of the connecting cavities and the fasteners for fixed coupling with mandrel. The advantage is a stronger connection of elements as well as delimitation of precise relative position of the elements.

The elements are preferably placed freely towards the subfloor during laying down the floor, by which a production of the floor of a floating floor type is achieved. Adequately to the need of the shift on the subfloor due to the humidity and temperature changes, a free expansion gap is left on the edges of the floor installed in this way, because of the possibility of moving according to the material dilatation in these floors, especially in the case of larger flooring areas.

The invention is suitable especially for floors of the type of floating floors, for overlay flooring, and for industrial floors from boards, narrow elements or panels. The floors produced according to the invention are strong and highly resistant to load, unequal pressures, leaks etc. The greatest advantage of these floors is the fact that no undesirable cracks between elements and gaping joints appear even after prolonged period of use, at critical operation conditions, or on large flooring areas. Great advantage is that the fasteners according to the invention will pull the floor elements together. The floors according to the invention have very long service life. Installed floor is highly resistant even to dry shrinkage and swelling. During assembly of the floor, only some elements can have the connecting cavities or the other way round, the connecting cavities can be on all elements. System of connecting cavities can be preferably combined with a system of click locks used today already as a matter of routine in various forms for floating floors, and also with gluing of adjacent elements using special adhesives to ensure cohesion of produced floor. The invention is suitable especially for floors, but it is suitable for lining of facades, interiors and bathrooms, especially for the^" wooden ones. If no adhesive is used during assembly, easy disassembly of the floor or partial disassembly is also possible, with the optional possibility to replace damaged element of several elements. Other advantage of floors according to the invention is the possibility to sand the completed floor and to surface it by various means such as varnishing or impregnation with wax etc. The invention allows using boards or elements of bigger thickness for example for a grid under a heating system etc. The invention is suitable especially for elements of bigger thickness, it is not intended for thin and extremely thin elements. The invention allows using optimal length of the fastener mandrels according to the shape, dimensions and structure of the elements, for example longer mandrels such as 1.3 times longer than the element width are used in the case of necessity to increase the floor strength and to prevent longitudinal cracking. Review of Figures on Drawings

The invention is illustrated using drawings, where Fig. 1 shows perspective top view of vertical section passing through the example of assembled floor with elements connected by wood screws and containing the connecting cavity with two diameters, Fig. 2 shows front view of vertical section passing through the floor in the case of connection by wood screw with a head leaning in the peripheral longitudinal groove of the elements containing the connecting cavity of one diameter, Fig. 3 shows front view of vertical section passing through the floor in the case of the connection using two-head connecting bolt with heads leaning in the linked-up connecting cavities of two diameters, Fig. 4 shows front view of vertical section passing through the floor in the case of the connection by connecting bolts with a furniture nut, with the bolt head leaning in the connecting cavity of two diameters, Fig. 5 shows front view of vertical section passing through the floor in the case of the connection by connecting bolts with a countersunk nut, with the bolt head leaning in the connection cavity of two diameters, Fig. 6 shows diagram drawing of the procedure during the floor production in individual phases A to D, Fig 7 shows perspective bottom view of vertical section through the example of assembled floor with the connecting cavities in the form of a recess, and Fig. 8 shows left side view on vertical section through the floor according to the previous figure when the section is drawn along the line A-A indicated on the previous figure. Best Mode for Carrying Out the Invention

Descriptive example of the optimal embodiment of the invention is the prefabricated floor according to the Fig. 1 and Fig. 6.

Prefabricated floor creates a planar formation assembled from the layer of flat elements 1 , 2, 3 placed next to each other, with a face side on the top and a reverse side at the bottom. The elements 1, 2, 3 have in them created connecting cavities 4 in the form of openings running past the face surface from one side to the other side through each element 1, 2, 3. The connecting cavities can have gentle or even almost imperceptible slope or they are parallel with the face surface as shown on Figure 1 , but in all cases it is the direction of the line pointing always from one side of the first element 1 through all its body to the adjacent second element 2 and not off it. Adjacent elements 1 , 2, 3 are interconnected and preferably tightened with the help of fasteners 5 for fixed coupling with a mandrel, in this example in the form of a wood screw. There is one wood screw placed in each in connecting cavity 4 selected by the maker for fastening, one part of said screw is located in the connecting cavity 4 of the first element 1 and the other part protrudes from this connecting cavity 4 into the body of adjacent element 2, where it is firmly fixed.

Fig. 1 shows section through the connection in the place of the first element 1 in a preferred embodiment, in which the connecting cavity 4 of two different diameters is created. The larger diameter of these two is by its dimensions adapted to the size of the wood screw head 6 and the smaller diameter is adapted to the size of the wood screw stem. The connecting cavity 4 runs across the shown first element 1 in its transversal direction, that is perpendicular to its edge and preferably in the shortest possible way.

The shown example is the case of board elements 1 , 2, 3 with a classic lateral connection with a tongue and groove 7. That is why each element 1 , 2, 3 has a tongue created on one lateral side and a longitudinally running groove 7 created on the other side, into which the tongue engages.

As shown on Fig. 2, this groove 7 can be utilised for seating of the head 6 of the fastener 5. In such case the connecting cavity 4 can have a simple shape of a drilled opening of one diameter along all its passage, as it is also shown on the Fig. 2. If the elements 1 2, 3 are made of solid timber and it is not discernible which side is the face side, they are laid during installation of the floor so that always one of the pair of the interconnected elements 1 , 2, 3 has the groove 7 on the side intended for the entry of the mandrel of the fastener 5 and the head 6 of the fastener 5 will then during assembly lean against the end of said groove 7. This solution is suitable for connection with the help of wood screws and for elements 1. 2, 3 having some groove 7 on at least part of some of its lateral sides, preferably running here in the longitudinal direction, while at least one connecting cavity 4 made in this element 1 , 2, 3 runs out from this groove 7.

There is no need to use necessarily the wood screw as the fastener 5 for fixed coupling, even though this connection is probably the most advantageous because of easy assembly, easy disassembly, and low acquisition price. Figures Fig. 3 to Fig. 5 show examples of other alternative types of applicable fasteners 5,_. The method of fixation of the ends of the fastener 5, especially the method of fixation of the end located in the second element 2, then corresponds to the used type of selected fastener 5,

Fig. 3 shows connection with two-head connecting bolt. The elements 1 , 2, 3 are for such fastening placed to each other so that the connecting cavities 4 are linked-up to each other always at the first and second element The connecting cavities 4 are produced with two diameters and these elements 1 , 2 are turned with the narrower diameter towards each other. Both heads 6 of the screw are leaning in the connecting cavities 4 against the start of their narrower parts.

Fig. 4 shows a connection using connecting bolt with a furniture nut 8. The head 6 of the bolt is abutted in the connecting cavity 4 of two diameters against the place of its narrowing inside the first element 1 and the furniture nut 8 is embedded in advance in the second element 2. Fig. 5 shows a connection using connecting bolt with a countersunk nut 9. The head 6 of the bolt is like in the previous examples abutted against in the connecting cavity 4 of two diameters inside the first element 1. The sunk nut 9 is pre-inserted in the longitudinal groove 7 of the second element 2.

The connecting cavity 4 can be in the number of one, two, or more and that only on some or on all elements 1. 2, 3. In the case when larger elements 1, 2, 3 are contained, it is more preferable to include two or more connecting cavities 4. In such case, the connecting cavities 4 are preferably running in parallel to each other and are preferably located in regular distances between each other. The marginal connecting cavities 4 can be placed in a corresponding link-up for the case that additional elements 1 , 2, 3 are laid down one on the back of the other in the longitudinal direction during the floor installation.

The example of layout of the floor with the connecting cavities 4 realised as a recess in the reverse side of the elements 1 , 2, 3 is shown on figures Fig. 3 and Fig. 9. It is practically an analogy of the layout described in the previous examples with that difference that transverse recesses are cut in the elements 1 , 2, 3 instead of drilling openings. Figure Fig. 8 visually demonstrates occurrence of the row of connecting cavities 4 in regular distances.

Prefabricated floor according to the invention can include fasteners 5 of various lengths, for example a shorter wood screw in the case of appearance of knot or other obstacle to an easy fixation in the second connected element 2.

Prefabricated floor according to the invention can be made even from plain boards with flat side walls. However it is an advantage when the adjacent elements 1 , 2, 3 can be fixed besides the connecting cavities 4 with fasteners 5 for fixed coupling of the type of screws etc., also with the help of inter-engaging shape. Optimally with the help of connecting protrusions and connecting recesses created on the counterparts, both in the form of means for ensuring precise relative position of the elements 1 , 2, 3 in the connected state. The invention can be utilised also to improve the quality of a floor with joints between the elements 1, 2J3 of the type with slip tongue, inserted dowel pins, inserted dilatation or inserted interlayer from a decorative element, in the case of glued joints between the elements 1 , 2, 3, etc. Figure Fig. 6 shows schematically the procedure of production of the prefabricated floor according to the invention.

The floor is created as a layer from the elements 1 , 2, 3, by sequential laying of said elements next to each other on the place of destination and fixing, whereas in the background art the elements 1 , 2, 3 are fixed to their place by means of drilling of vertical cavities and subsequent fixing to the place of destination with the help of sticking in wood screws from the top downwards through the face surface into the subfloor through these vertical cavities and immovable connection of the elements 1 , 2. 3 to the subfloor is achieved, the connection according to the invention is done in the horizontal direction and the result of the type of floating floor is achieved. Selected connected elements 1 are first, optimally as soon as at the manufacturer and at the latest during laying, fitted with connecting cavities 4 passing across the whole relevant element 1 in the direction skew towards the face surface from one side to the opposite side in the direction to the adjacent second element 2 to which the said first element 1 being connected should be fastened, taken according to the position of the elements 1 , 2, 3 in the assembled floor. The floor is made so that the first element being connected that is equipped with the connecting cavities 4 is placed to the other, on figures second, element 2 already laid on the place of destination. The fastener 5 for fixed coupling comprising a mandrel, for example screw, is placed into the selected connecting cavity 4 after which the end of this fastener 5 is embedded through the connecting cavity 4 into the body of the adjacent element 2 and firmly fixed here. In the case of wood screw, this fixing will take place by embedding of at least the end of the threaded part. Simultaneously at least part of the mandrel of the fastener 5,. for example screw stem, is left in the connecting cavity 4 of the first element 1 being connected, and the opposite end of the fastener 5, for example screw head (6), is firmly fixed in the first element 1 being connected by leaning either against longitudinal groove 7, or against reduction of the connecting cavity 4. In the course of the whole process of laying the floor, each placing and fixing of the fastener 5 by means of these connecting cavities 4 is done off the face sides of the element 1 being connected as well as of the element 2 already laid on the place of destination. The connecting cavities 4 are hollowed into the elements 1 , 2, 3 preferably in parallel with the face surface of the element, and that is done either by drilling through the elements 1 , 2, 3 while creating openings or by milling from the reverse side of the elements 1 , 2, 3 to cerate recesses.

Preferably the connecting cavity 4 is produced with two diameters while this dimension difference is utilised for seating of the head 6 of the fastener 5. This is done in the following way. At least one section of the connecting cavity 4 is made with a diameter larger than the diameter of another section of the same connecting cavity 4, and then during laying the floor, the drilled through first element 1 is placed with the orifice of the narrower part of the connecting cavity 4 to the other already laid second element 2, and the fastener 5 with head 6 is placed, mandrel first, into the so situated connecting cavity 4 via its broader part, and it is placed there up to stop, that means so far that the head 6 of the fastener 5 is leaning against the place of reduction of the connecting cavity 4. The fasteners 5 of such length are used so that the end of their mandrel overlaps and thus can be sunk into the already laid second element 2.

In the case of connecting by means of wood screws or nails, the first element 1 is laid to the already laid down second element 2 so that the connecting cavity 4 leads to an integral part of the side wall of the already laid down second element 2.

The most preferable case is when all contained connecting cavities 4 have identical shape and dimensions. It is the easiest way from the point of production and it is also convenient for the floor layer because he can estimate and easily solve also possible problematic areas in the floor. For example fasteners 5 of various lengths can be purposefully placed into different connecting cavities 4 so that they would not reach into knots or other problematic areas in material.

The connecting cavities 4 are preferably hollowed in the direction of width of the elements 1 , 2, 3, that is perpendicular across their shorter side, and that also preferably in a row with regular spacing. The distance of the terminal connecting cavities 4 from the ends of the element 1 , 2, 3 is selected preferably so that in the case when the elements 1 , 2, 3 are adjoined linked-up in the length direction, the resulting spacing between the terminal connecting cavities 4 of adjoined elements is the same as the spacing between the neighbouring connecting cavities 4 in the row. Consequently in the case of elements with flat end walls, which are laid to each other and not over each other during laying, the distance between the terminal connecting cavities (4) and the ends of elements (1 ,^"2, 3) equals to the half of the distance between the neighbouring connecting cavities (4) in the row. Preferably the method according to the invention is combined with classic laying. The invention can then be used to improve the result in existing floating floors, or the connecting cavities 4 according to the invention as well as some of the classic or modern types of locks based on projections on the first element and the corresponding recess in the neighbouring second element 2, for example of the type of tongue and groove or dovetail latch, are produced on all elements in the course of production of elements 1 , 2, 3. Then during laying of the floor, the adjacent elements are interconnected first with the help of these locks and after that with the help of the connecting cavities 4 and the fasteners 5 for fixed coupling with mandrel. The elements are placed preferably freely towards the subfloor during laying down the floor, and a free expansion gap is left on the edges of the floor produced in this way.

Claims

C L A I M S

1. Prefabricated floor in the form of planar formation created by the layer of flat elements (1 , 2, 3) placed next to each other and each having a face side and a reverse side, characterized by that at least some elements (1 , 2, 3) have in them created at least one connecting cavity (4) running past the face surface from their one side to the opposite side and that in the direction of the line pointing to the adjacent element (1 , 2, 3), while the adjacent elements (1 ,2) are interconnected with the help of at least one fastener (5) for fixed coupling with a mandrel, one part of which is located in the connecting cavity (4) of the first element (1 ) and the other part protrudes from this connecting cavity (4) into the body of the other adjacent element (2) where it is firmly fixed.

2. Prefabricated floor according to the claim 1 characterized by that the connecting cavity (4) is in the shape of an opening.

3. Prefabricated floor according to the claim 1 characterized by that the connecting cavity (4) is in the shape of a recess in the reverse surface of the element (1 , 2, 3).

4. Prefabricated floor according to any of the claims 1 to 3 characterized by that the connecting cavity (4) has within the frame of its routing at least two different diameters, of which the larger diameter is for passage of the head (6) of the fastener (5) for fixed coupling with a head (6), for example for the head (6) of a screw, and the smaller diameter is for the mandrel of said fastener (5), for example for the screw stem.

5. Prefabricated floor according to any of the claims 1 to 4 characterized by that the connecting cavity (4) runs parallel with the plane of the face surface of the element (1 , 2, 3).

6. Prefabricated floor according to any of the claims 1 to 5 characterized by that the connecting cavity (4) runs across the element (1 , 2, 3) in its transversal direction.

5 7. Prefabricated floor according to the claim 6 characterized by that at least one element (1 ) containing the connecting cavity (4) has on its side for the entry of the mandrel on at least part of this side of its created at least one groove (7) for the head (6) of the fastener (5) and the connecting cavity (4) has its start in this groove (7).

o

8. Prefabricated floor according to any of the claims 1 to 7 characterized by that at least one element (1 , 2, 3) contains at least two connecting cavities (4).

9. Prefabricated floor according to the claim 8 characterized by that at least5 one element (1 , 2, 3) contains at least three connecting cavities (4) that are running on it parallel to each other in regular distances.

10. Prefabricated floor according to any of the claims 1 to 9 characterized by that the adjacent elements (1 , 2) interconnected with the help of connecting0 cavities (4) and fastener (5) have mutually engaging shape of which one element (1 ) has created at least one connecting projection and the other element (2) has created at least one connecting recess for this projection, both in the form of means for ensuring precise relative position in the connected state. 5

1 1 . Method of production of prefabricated floor according to any of the claims 1 to 10 in which the completed floor is created as a layer from the elements (1 , 2, 3) by sequential laying of said elements next to each other on the place of destination and fixing, while at least some elements (1 , 2, 3) are fixed to their place by means of hollowing of the connecting cavities (4) and fixing with the help of fasteners (5)0 for fixed coupling with a mandrel led through the connecting cavities (4) created in this way, characterized by that the connecting cavities (4) are made into at least some of the elements (1 , 2, 3) in a way skew towards the face surface so that to run from one lateral side of the element (1 , 2, 3) through its body to the opposite lateral side, after which the floor is then made so that after that, when the first element (1 ) being connected and containing the connecting cavity (4) is placed to the other, second element (2) already laid on the place of destination, the fastener (5) for fixed coupling comprising a mandrel is placed into the connecting cavity (4) of the first element (1 ) and the end of this fastener (5) is embedded through the connecting cavity (4) into the body of the adjacent second element (2) and firmly fixed here, while at least part of the mandrel is left in the connecting cavity (4) of the first element (1 ) and the opposite end of the fastener (5) is firmly fixed in the first element (1), and in the course of the process of laying the floor, the sequential placing and fixing of the fasteners (5) is done utilizing different connecting cavities (4) in different elements (1 , 2, 3), out of the face side of these elements (1 , 2, 3).

12. Method of production of prefabricated floor according to the claim 11 characterized by that the connecting cavities (4) are hollowed into the elements (1 , 2, 3) in parallel with their face surface and that either by drilling through while creating openings, or by milling from the reverse side of elements (1 , 2, 3) to cerate groove-like recess.

13. Method of production of prefabricated floor according to the claims 1 1 and 2 characterized by that at least one section of the connecting cavity (4) is made with a diameter larger than diameter of another section of the same connecting cavity (4), and then during laying the floor, the first element (1) with such connecting cavity (4) is placed with the orifice of the narrower part of the connecting cavity (4) to already laid second element (2), and the fastener (5) with head (6) is inserted, mandrel first, into the connecting cavity (4) via its broader part, and it is fixed here with its head (6) up to stop, that means so far that the head (6) of the fastener (5) is leaning against the place of reduction of the connecting cavity (4) and in doing so, the fasteners (5) of such length are used so that the end of the fastener (5) mandrel emerges from the first element (1) and sinks into the second element (2).

14. Method of production of prefabricated floor according to the claims 1 to 13 characterized by that the first element (1 ) is laid during the floor installation to another already laid second element (2) so that each connecting cavity (4) of said first element (1) that will be utilised for the fastener (5) leads to an integral part of the side wall of the second element (2).

15. Method of production of prefabricated floor according to the claims 11 to 14 characterized by that different connecting cavities (4) are made with the same dimensions, however then the fasteners (5) of various lengths are placed purposefully into various connecting cavities (4) so that said fasteners (5) will not reach into knots or other areas of worsened penetrability of material.

16. Method of production of prefabricated floor according to the claims 1 to 15 characterized by that the connecting cavities (4) are hollowed so as to run in the direction of the width of the element (1 , 2, 3) and to create on individual elements (1 , 2, 3) a row, in which the connecting cavities (4) are located in regular spacing while the distance of the end connecting cavities (4) from the ends of the element (1 , 2, 3) is selected so that in the case when the elements (1 , 2, 3) are put together linked-up in the length direction, the resulting spacing between the end connecting cavities (4) of adjoined elements (1 , 2, 3) is the same as the spacing between the neighbouring connecting cavities (4) in the row.

17. Method of production of prefabricated floor according to the claims 1 to 16 characterized by that in addition to the connecting cavities (4), also locks, for example locks based on at least one projection on one element (1) engaging to a corresponding recess in the neighbouring element (2), are made on all elements (1 , 2, 3), and then during production of the floor, all adjacent elements (1 , 2, 3) are interconnected first with the help of these locks and after that at least some elements are interconnected with the help of the connecting cavities (4) and the fasteners (5) for fixed coupling with mandrel.

18. Method of production of prefabricated floor according to the claims 11 to 17 characterized by that the elements (1 , 2, 3) are placed freely towards the subfloor during laying down the floor and a free expansion gap is left on the edges of the floor installed in this way.