Patent Publication Number: US-2022213694-A1

Title: Floor panel for forming a floor covering

Description:
The invention concerns a floor panel for forming a floor covering, more particularly for forming a floor covering which can be installed on a substrate. 
     More particularly, the invention concerns floor panels which can be coupled together by means of mechanical coupling parts. 
     The object of the invention is to ensure that a floor covering made of such floor panels can be installed easily, but at the same time provides sufficient stiffness in the floor covering, more particularly, sufficiently rigid connections between the floor panels can be achieved, in combination with production techniques which limit the production cost. 
     In the first place, the invention concerns floor panels which can be installed using the so-called fold-down technique, in order to meet the specified requirements for simple installation. Here, two of the edges, usually the short edges in the case of oblong floor panels, can be joined together via a downward movement wherein then an interlock is created between the respective edges in a vertical direction perpendicularly to the plane of the coupled panels, and in a horizontal direction in the plane of the coupled panels and perpendicularly to the edges concerned. The interlock in the vertical direction may be achieved with separate elastic locking strips, as is the case for example in WO 2013/118030. This is however costly to implement and apply. To exclude this cost, integral or mainly integral coupling profiles may be used, as is the case for example in WO 2017/115202. Integral coupling parts may have the disadvantage that a compromise must be reached between connection strength and ease of installation; either the connection is too stiff and the floor panels cannot be joined together, or only joined together by damaging them, or the coupling offers too little resistance against unlocking. The quality of the coupling depends greatly on the configuration details and the compressibility and/or flexibility of the materials used. 
     Other examples of coupling means which can be installed via fold-down methods are known for example from WO 2012/101171, EP 3 031 998 and EP 2 615 221 B1. 
     The present invention primarily concerns the provision of an alternative floor panel, wherein according to various preferred embodiments, a solution is offered to one or more problems associated with the floor panels from the prior art. In particular, according to various independent aspects, the invention provides a number of combinations of features with which significant improvements may be achieved in floor panels with integral coupling parts, and in particular with integral vertically active locking parts, by use of specific structural properties and/or material characteristics and/or design of the coupling parts. 
     For this, in its first independent aspect, the invention concerns a floor panel for forming a floor covering, wherein the floor panel has a first pair of mutually opposing edges and a second pair of mutually opposing edges; wherein the first pair of mutually opposing edges comprises coupling parts which allow two of such floor panels to be coupled together, and wherein these coupling parts have the following features: 
     the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the coupling parts are preferably configured such that two of such panels can be coupled together at these edges by means of a rotational movement;
 
wherein the second pair of mutually opposing edges also comprises coupling parts on both edges, which allow two of such floor panels to be coupled together and wherein these coupling parts have the following features:
 
the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the horizontally active interlock system of the second pair of edges is at least formed by an upwardly pointing bottom hook-shaped part which is situated on one of said two edges, and a downwardly pointing top hook-shaped part which is situated on the opposite edge, wherein the bottom hook-shaped part consists of a lip with an upwardly pointing locking element which proximally thereto defines a female part in the form of a recess, while the top hook-shaped part consists of a lip with a downwardly pointed locking element which forms a male part;
 
the coupling parts are configured such that two of such floor panels can be coupled together at their respective edges by means of a downward movement of the one floor panel relative to the other;
 
the vertically active interlock system comprises vertically active locking parts which, by means of respective contact faces define at least a first locking zone and a second locking zone, wherein said first locking zone comprises a first locking part formed on a distal surface of the male coupling part, and cooperating therewith a second locking part of the female part, and said second locking zone comprises a third locking part on a distal surface of said lip of the bottom hook-shaped part, and cooperating therewith a fourth locking part of the floor panel coupled thereto;
 
with the feature that the following combination of features is present on the second pair of edges: the horizontally active interlock system of the second pair of edges comprises contact faces formed between the upwardly pointing locking element and the downwardly pointing locking element, wherein these contact faces extend from bottom to top in a direction away from said first locking zone;
 
the male part, during said downward movement (M), may be brought without deformation into the female part to a position in which the downwardly pointing locking element makes contact with the upwardly pointing locking element, wherein this contact on the upwardly pointing locking element is located above said contact faces which are formed in the coupled state. In other words, this initial contact is created in the finally coupled state, and at the location of this original contact on the upwardly pointing locking element, a space is present between the upwardly pointing locking element and the downwardly pointing locking element.
 
     The surface of the upwardly pointing locking element at which the initial contact is formed may serve as a guide surface and can be given any form for supporting the coupling of the male and female parts. Preferably, the part of the surface of the upwardly pointing locking element on which the initial contact is formed extends in a direction which deviates from the direction of extension of said contact faces, available in the finally coupled state. Preferably, both the contact faces and the surface present above these of the upwardly pointing locking element on which the initial contact is formed, extend in directions away from said first locking zone, wherein the contact faces form an angle with the vertical which is smaller than the angle which the upper surface encloses with the vertical. Preferably, the contact faces enclose an angle of 1° to 10° with the vertical. 
     With the same object as in the first aspect, according to a second independent aspect, the present invention concerns a floor panel for forming a floor covering, wherein the floor panel has a first pair of mutually opposing edges and a second pair of mutually opposing edges; wherein the first pair of mutually opposing edges comprises coupling parts which allow two of such floor panels to be coupled together, and wherein these coupling parts have the following features: 
     the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the coupling parts are preferably configured such that two of such panels can be coupled together at these edges by means of a rotational movement;
 
wherein the second pair of mutually opposing edges also comprises coupling parts on both edges, which allow two of such floor panels to be coupled together and wherein these coupling parts have the following features:
 
the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the horizontally active interlock system of the second pair of edges is at least formed by an upwardly pointing bottom hook-shaped part which is situated on one of said two edges, and a downwardly pointing top hook-shaped part which is situated on the opposite edge, wherein the bottom hook-shaped part consists of a lip with an upwardly pointing locking element which proximally thereto defines a female part in the form of a recess, while the top hook-shaped part consists of a lip with a downwardly pointed locking element which forms a male part;
 
the coupling parts are configured such that two of such floor panels can be coupled together at their respective edges by means of a downward movement of the one floor panel relative to the other;
 
the vertically active interlock system comprises vertically active locking parts which, by means of respective contact faces define at least a first locking zone and a second locking zone, wherein said first locking zone comprises a first locking part formed on a distal surface of the male coupling part, and cooperating therewith a second locking part of the female part, and said second locking zone comprises a third locking part on a distal surface of said lip of the bottom hook-shaped part, and cooperating therewith a fourth locking part of the floor panel coupled thereto;
 
with the feature that furthermore the following combination of features is present on the second pair of edges:
 
the horizontally active interlock system of the second pair of edges comprises contact faces formed between the upwardly pointing locking element and the downwardly pointing locking element, wherein these contact faces extend from bottom to top in a direction away from said first locking zone;
 
the vertically active interlock system furthermore comprises contact faces between the downwardly pointing locking element and the lip of the bottom hook-shaped part, wherein these contact faces are at least situated on the half of said female coupling part which is located closest to the upwardly pointing locking element. The contact faces concerned form a support surface for the male part. The interaction between the upwardly pointing locking element and the adjacent support surface ensures a good coupling with a limited risk of splitting or height differences after coupling.
 
     Preferably, said contact faces of the vertically active interlock system are situated on a part of the female coupling part which is situated at a distance from the upper edge of the panel edge with the female coupling part. Preferably, this distance amounts to at least 20 percent of the thickness of the floor panel and/or at least half of the distance between the upper edge and the contact faces of the horizontally active interlock system, more particularly at least half of the distance between the upper edge and the lowest point of the contact faces of the horizontally active interlock system. 
     Preferably, said contact faces of the vertically active interlock system adjoin or practically adjoin the contact faces of the horizontally active interlock system. In some cases, a gap may be enclosed between the two pairs of contact faces, for example because they are joined to each other by means of a chamfer or rounding. 
     It is clear that the floor panel of the second aspect may have the properties of the first aspect and/or preferential embodiments thereof. 
     With the same object as in the first aspect, according to a third independent aspect, the present invention concerns a floor panel for forming a floor covering, wherein the floor panel has a first pair of mutually opposing edges and a second pair of mutually opposing edges; wherein the first pair of mutually opposing edges comprises coupling parts which allow two of such floor panels to be coupled together, and wherein these coupling parts have the following features: 
     the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the coupling parts are preferably configured such that two of such panels can be coupled together at these edges by means of a rotational movement;
 
wherein the second pair of mutually opposing edges also comprises coupling parts on both edges, which allow two of such floor panels to be coupled together and wherein these coupling parts have the following features:
 
the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the horizontally active interlock system of the second pair of edges is at least formed by an upwardly pointing bottom hook-shaped part which is situated on one of said two edges, and a downwardly pointing top hook-shaped part which is situated on the opposite edge, wherein the bottom hook-shaped part consists of a lip with an upwardly pointing locking element which proximally thereto defines a female part in the form of a recess, while the top hook-shaped part consists of a lip with a downwardly pointed locking element which forms a male part;
 
the coupling parts are configured such that two of such floor panels can be coupled together at their respective edges by means of a downward movement of the one floor panel relative to the other;
 
the vertically active interlock system comprises vertically active locking parts which, by means of respective contact faces define at least a first locking zone and a second locking zone, wherein said first locking zone comprises a first locking part formed on a distal surface of the male coupling part, and cooperating therewith a second locking part of the female part, and said second locking zone comprises a third locking part on a distal surface of said lip of the bottom hook-shaped part, and cooperating therewith a fourth locking part of the floor panel coupled thereto;
 
with the feature that the following combination of features is present on the second pair of edges: the horizontally active interlock system of the second pair of edges comprises contact faces formed between the upwardly pointing locking element and the downwardly pointing locking element, wherein these contact faces extend from bottom to top in a direction away from said first locking zone;
 
the upwardly pointing locking part on its underside has a recess, wherein the theoretical line between the proximal point of said recess and the lowest point of the contact faces forms an angle with the vertical of 0° to 35°, wherein preferably the proximal point of the recess is distal from the lowest point of the contact faces, or in other words said theoretical line runs from said proximal point of the recess inwardly to the lowest point of the contact faces.
 
     The configuration of the recess presented in the third aspect gives a combination of a good connection strength with greater ease of installation. 
     It is clear that the floor panel of the third aspect may have the features of the first and/or second independent aspects, and/or preferential embodiments thereof. 
     With the same object as in the first aspect, according to a fourth independent aspect, the present invention concerns a floor panel for forming a floor covering, wherein the floor panel has a first pair of mutually opposing edges and a second pair of mutually opposing edges; wherein the first pair of mutually opposing edges comprises coupling parts which allow two of such floor panels to be coupled together, and wherein these coupling parts have the following features: 
     the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the coupling parts are preferably configured such that two of such panels can be coupled together at these edges by means of a rotational movement;
 
wherein the second pair of mutually opposing edges also comprises coupling parts on both edges, which allow two of such floor panels to be coupled together and wherein these coupling parts have the following features:
 
the coupling parts comprise a horizontally active interlock system which, in a coupled state of two of such floor panels, realizes a lock in the plane of the floor panels perpendicularly to the edges concerned;
 
the coupling parts also comprise a vertically active interlock system which, in a coupled state of two of such floor panels, realizes a lock transversely to the plane of the floor panels;
 
the coupling parts are preferably made mainly from the material of the floor panel itself; and
 
the horizontally active interlock system of the second pair of edges is at least formed by an upwardly pointing bottom hook-shaped part which is situated on one of said two edges, and a downwardly pointing top hook-shaped part which is situated on the opposite edge, wherein the bottom hook-shaped part consists of a lip with an upwardly pointing locking element which proximally thereto defines a female part in the form of a recess, while the top hook-shaped part consists of a lip with a downwardly pointed locking element which forms a male part;
 
the coupling parts are configured such that two of such floor panels can be coupled together at their respective edges by means of a downward movement of the one floor panel relative to the other;
 
the vertically active interlock system comprises vertically active locking parts which, by means of respective contact faces define at least a first locking zone and a second locking zone, wherein said first locking zone comprises a first locking part formed on a distal surface of the male coupling part, and cooperating therewith a second locking part of the female part, and said second locking zone comprises a third locking part on a distal surface of said lip of the bottom hook-shaped part, and cooperating therewith a fourth locking part of the floor panel coupled thereto;
 
with the feature that the following combination of features is present on the second pair of edges: the horizontally active interlock system of the second pair of edges comprises contact faces formed between the upwardly pointing locking element and the downwardly pointing locking element, wherein these contact faces extend from bottom to top in a direction away from said first locking zone, wherein the contact faces enclose an angle with the vertical from 1° to 10°.
 
     Such steep contact faces of the horizontally active interlock system give a good connection strength. 
     It is clear that the floor panel of the fourth aspect may also have the features of the first and/or second and/or third aspects, and/or preferential embodiments thereof. 
     In general, the floor panel of any of said aspects may furthermore have one or more of the following properties, or any mutual combination of these properties, insofar as such a combination does not contain conflicting properties: 
     the coupling parts are configured on the floor panel such that the floor panels can be installed following the fold-down principle;
 
the floor panel is oblong rectangular, and the first pair of mutually opposing edges forms the long sides of the floor panel while the second pair of mutually opposing edges forms the short sides of the floor panel;
 
the coupling parts on the second pair of edges may be joined together via a downward snap movement;
 
the coupling parts of the first and/or second pair of edges are largely configured as profiles in the material of the floor panel, preferably largely or completely by means of material-removal machining, preferably by means of one or more milling operations, for example with milling cutters which are active at different working angles;
 
the coupling parts on the first and/or second pair of edges are configured as millable profiles which can be milled with milling cutters with a rotational axis which is located outside the floor panels during milling;
 
said male part may or may not be split;
 
only one male part, which may or may not be split, is applied to the second pair of edges; the contact faces of the second and/or fourth locking part, preferably of both, is/are configured so as to be flat;
 
the contact faces of the second and/or fourth locking part, preferably of both, is/are formed curved; here, the contact face of the fourth locking part is preferably convex while the contact face of the second locking part is flat or curved, preferably concave;
 
the bottom hook-shaped part, and more particularly the lip thereof, can be elastically bent and/or elastically deformed;
 
a recess is present at the bottom of the lip, preferably configured such that the upwardly pointing locking element can be tilted elastically;
 
a space is present below the male part;
 
in coupled state, a space is present behind the distal end of the bottom hook-shaped part;
 
in coupled state, a space is present above the upwardly pointing locking element, which space is preferably formed continuously with the space mentioned in the preceding paragraph;
 
the centre point of the first locking zone is situated higher than the centre point of the second locking zone;
 
the coupling parts on the first pair of edges and/or on the second pair of edges are completely integrally made of the material of the floor panel, more particularly from a substrate which forms part of the floor panel;
 
the distal end of the top hook-shaped part above said first locking zone is completely free from downwardly active support points, or at least free from support points which, in coupled state, define tangents which make an angle with a horizontal of less than 45°;
 
the coupling parts on the first pair and/or second pair of edges are configured such that in coupled state, a so-called pretension exists which presses the floor panels concerned towards each other at the respective edges, wherein this takes place preferably by use of overlapping contours, and wherein the pretension is the result of a deformation, either an elastic bending or an elastic compression or a combination of both;
 
the coupling parts on the second pair of edges are free from hook &amp; loop closures and/or glue connections;
 
on the first and/or second pair of edges, the floor panel is provided with chamfers;
 
the floor panel has a top layer and/or decor layer which extends integrally from the horizontal top surface of the floor panel up to the chamfers;
 
the chamfers are formed by impressions;
 
the floor panel has a top layer with a decor;
 
the floor panels have a substrate which may or may not be multipiece, and which may or may not consist of several substrate layers, wherein the substrate or, in the case of several layers, at least one of the substrate layers consists of a material which fulfils one or more or any combination of the following features, insofar as such a combination does not contain any conflicting features:
 
plastic-based material, foamed or not foamed, resilient or hard, with or without plasticizer, filled or not filled with a wood-based or bamboo-based material for example in the form of fibres, chips, dust or sawdust, and/or filled with other substances e.g. chalk, lime, talc, ground stone-based fillers;
 
plastic-based material which is foamed with fine pores so that the majority of the plastic-based material contains pores and/or gas inclusions with dimensions of less than 1 mm, preferably less than 0.1 mm and even more preferably less than 0.01 mm;
 
plastic-based material which is obtained by extruding plastic-based raw material in the form of sheet material, wherein in a preferred embodiment this material is foamed, this in turn preferably has fine pores which are such that the majority of the plastic-based material contains pores and/or gas inclusions with dimensions of less than 1 mm, preferably less than 0.1 mm and even more preferably less than 0.01 mm;
 
plastic-based material which is obtained by spreading plastic-based raw material, which may or may not be combined with other materials, by means of a spreading process and consolidating this into the form of sheet material under the influence of pressure and in some cases increased temperature, wherein in a preferred embodiment the resulting material is foamed, this in turn preferably has fine pores which are such that the majority of the plastic-based material contains pores and/or gas inclusions with dimensions of less than 1 mm, preferably less than 0.1 mm and even more preferably less than 0.01 mm;
 
plastic consisting of or based on or containing one of the following materials: polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyurethane (PUR), polyvinyl chloride (PVC), polyisocyanurate (PIR) or other suitable plastics;
 
plastic-based material with plasticizers, wherein the plastic-based material is preferably selected from the material stated in the preceding paragraph;
 
wood-based material, for example MDF, HDF, prefabricated wood panels, more particularly so-called engineered wood panels, where applicable with adapted core or end strips;
 
the floor panel is configured as one of the following types:
 
a laminate floor panel;
 
a so-called resilient floor panel;
 
an LVT panel or CVT panel or comparable panel based on a plastic other than vinyl;
 
a floor panel with a first plastic-based, preferably foamed substrate layer, and thereon a preferably thinner second substrate layer made of or based on vinyl or another plastic;
 
a floor panel with a hard plastic-based substrate.
 
     Preferably, the coupling parts of the first pair of edges, as stated, allow coupling by means of a rotational movement. According to an alternative embodiment, they are at least configured such that they can be coupled together by means of a downward movement. In such a case, coupling parts may also be used on the first pair of edges and have the features as described above for the second pair of edges. 
     According to a different variant of any of the above-mentioned aspects, in the first locking zone there is no vertical lock, and merely a horizontal lock is present 
    
    
     
       With the aim of presenting the features of the invention better, some preferential embodiments are described below as examples without limitative character, with reference to the appended drawings in which: 
         FIG. 1  shows diagrammatically and in perspective a part of a floor covering which consists of floor panels according to the invention; 
         FIG. 2  shows on a larger scale the part indicated by F 2  in  FIG. 1 ; 
         FIG. 3  shows in top view a floor panel from the floor covering of  FIGS. 1 and 2 ; 
         FIGS. 4 and 5  show on larger scale cross-sections along lines IV-IV and V-V respectively in  FIG. 3 ; and 
         FIG. 6  shows the coupling parts visible in  FIG. 4  on a larger scale and in coupled state. 
     
    
    
     As shown in  FIGS. 1 and 2 , the invention concerns floor panels  1  for forming a floor covering, which floor panels  1  have a first pair of mutually opposing edges  2 - 3  and a second pair of mutually opposing edges  4 - 5 . 
     The floor panels  1  shown are configured at their edges such that they can be coupled together following the so-called fold-down principle, which is a principle known in itself, for example from WO 01/75247, and in which such floor panels  1  can be coupled to each other at the first pair of edges  2 - 3  by a rotational movement R and at the second pair of edges  4 - 5  by a downward movement M, wherein the downward movement M is the result of the rotational movement R and hence occurs largely simultaneously. The floor panels  1  are here configured at their edges  2 - 3  and  4 - 5  such that finally, an interlock occurs in the vertical direction V and in the horizontal direction H, the latter being perpendicular to the edges concerned. 
     As shown in  FIGS. 3 to 6 , for this such a floor panel  1  is provided at its first pair of edges  2 - 3  with coupling parts  6 - 7 , while at the second pair of edges coupling parts  8 - 9  are provided, which coupling parts are described in more detail below with reference to  FIGS. 4 to 6 . 
     The coupling parts  6 - 7  of the first pair of edges  2 - 3 , as evident in  FIG. 5 , have at least the following basic features: 
     the coupling parts  6 - 7  comprise a horizontally active interlock system HL which, in a coupled state of two of such floor panels  1 , realizes a lock in the plane of the floor panels  1  perpendicularly to the edges concerned  2 - 3 ;
 
the coupling parts  6 - 7  also comprise a vertically active interlock system VL which, in a coupled state of two of such floor panels  1 , realizes a lock transversely to the plane of the floor panels, in other words in the vertical direction;
 
the coupling parts  6 - 7  are preferably made mainly from the material of the floor panel  1  itself; and
 
the coupling parts  6 - 7  are preferably configured such that two of such floor panels  1  can be coupled together at these edges by means of a rotational movement R.
 
     The coupling parts  8 - 9  of the first pair of edges  4 - 5 , as evident in  FIGS. 4 and 6 , have at least the following basic features: 
     the coupling parts  8 - 9  comprise a horizontally active interlock system which, in a coupled state of two of such floor panels  1 , realizes a lock in the plane of the floor panels  1  perpendicularly to the edges concerned  4 - 5 ;
 
the coupling parts  8 - 9  also comprise a vertically active interlock system which, in a coupled state of two of such floor panels  1 , realizes a lock transversely to the plane of the floor panels  1 ;
 
the coupling parts  8 - 9  are preferably made mainly from the material of the floor panel  1  itself; the horizontally active interlock system of the second pair of edges  4 - 5  is at least formed by an upwardly pointing bottom hook-shaped part  10  which is situated on one of said two edges, in this case the edge  4 , and a downwardly pointing top hook-shaped part  11  which is situated on the opposite edge  5 , wherein the bottom hook-shaped part  10  consists of a lip  12  with an upwardly pointing locking element  13  which proximally thereto defines a female part  14  in the form of a recess, while the top hook-shaped part  11  consists of a lip  15  with a downwardly pointed locking element  16  which forms a male part  17 ;
 
the coupling parts  8 - 9  are configured such that two of such floor panels  1  can be coupled together at their respective edges  4 - 5  by means of a downward movement M of the one floor panel relative to the other;
 
the vertically active interlock system comprises vertically active locking parts  18 - 19 - 20 - 21  which, by means of respective contact faces  22 - 23 - 24 - 25 , define at least a first locking zone C 1  and a second locking zone C 2 , wherein said first locking zone C 1  comprises a first locking part  19  formed on a distal surface of the male coupling part  17 , and cooperating therewith a second locking part  21  of the female part  14 , and said second locking zone C 2  comprises a third locking part  18  on a distal surface of said lip  12  of the bottom hook-shaped part  10 , and cooperating therewith a fourth locking part  20  of the floor panel  1  coupled thereto.
 
     The second pair edges  4 - 5  furthermore has the following combination of features: 
     the horizontally active interlock system of the second pair of edges  4 - 5  comprises contact faces  26 - 27  formed between the upwardly pointing locking element  13  and the downwardly pointing locking element  16 , wherein these contact faces  26 - 27  extend from bottom to top in a direction away from said first locking zone C 1 ;
 
as shown by the dotted line  28  on  FIG. 4 , the male part  17 , during said downward movement M, may be brought without deformation into the female part  14  into a position in which the downwardly pointing locking element  16  makes contact with the upwardly pointing locking element  13 , wherein this contact on the upwardly pointing locking element  13  is located above said contact faces  26 - 27  which are formed in the coupled state.
 
     Said initial contact is created in the finally coupled state, as shown on  FIG. 6 , and at the location of this original contact on the upwardly pointing locking element  13 , a space S is present between the upwardly pointing locking element  13  and the downwardly pointing locking element  16 . 
     The embodiment of the edges  4  and  5  shown in  FIGS. 4 and 6  again has the specific features of the second aspect of the invention described in the introduction, namely that: 
     the horizontally active interlock system of the second pair of edges  4 - 5  comprises contact faces  26 - 27  formed between the upwardly pointing locking element  13  and the downwardly pointing locking element  16 , wherein these contact faces  26 - 27  extend from bottom to top in a direction away from said first locking zone C 1 ;
 
the vertically active interlock system furthermore comprises contact faces  29 - 30  between the downwardly pointing locking element  13  and the lip  12  of the bottom hook-shaped part  10 , wherein these contact faces  29 - 30  are at least situated on the half  31  of said lip  10  which is located closest to the upwardly pointing locking element  13 .
 
     Preferably, said contact faces  29 - 30  of the vertically active interlock system are, as shown here, situated on a part of the female coupling part  14  which is situated at a distance D 1  from the upper edge  32  of the panel edge with the female coupling part  14 . Preferably, this distance is at least 20 percent of the thickness T of the floor panel  1  and/or at least half of the distance D 2  between the upper edge  32  and the contact faces  26 - 27  of the horizontally active interlock system. 
     Preferably, said contact faces  29 - 30  of the vertically active interlock system adjoin or practically adjoin the contact faces  26 - 27  of the horizontally active interlock system. In some cases, as here, a space S 1  may be enclosed between the two pairs of contact faces  26 - 27 ;  28 - 29 . 
     The embodiment of the edges  4 - 5  shown in  FIGS. 4 and 6  again has the specific features of the third aspect of the invention described in the introduction, namely that: 
     the horizontally active interlock system of the second pair of edges  4 - 5  comprises contact faces  26 - 27  formed between the upwardly pointing locking element  13  and the downwardly pointing locking element  16 , wherein these contact faces  26 - 27  extend from bottom to top in a direction away from said first locking zone C 1 ;
 
the upwardly pointed locking part  13  has a recess  33  on its underside, wherein the theoretical line  34  between the proximally located point  35  of said recess  33  and the lowest point of the contact faces  26 - 27  forms an angle A 1  with the vertical from 0° to 35°.
 
     In the example given here, the proximal point  35  of the recess  33  is distal from the lowest point of the contact faces  26 - 27 , or in other words said theoretical line  34  runs from said proximal point  35  of the recess  33  inward to the lowest point of the contact faces  26 - 27 . 
     It is pointed out that instead of the theoretical line  34 , a theoretical line may be considered between the lowest point of the contact faces  26 - 27  and the point  36  where the height H 1  of the recess  33  in the proximal direction is less than 0.25 mm. Such a restricted height of the recess  33  indeed only has a limited or no effect on the flexibility of the upwardly pointing locking element  13 . Such a theoretical line  34  then preferably fulfils the same features, namely that it forms an angle with the vertical of between 0° and 35°. 
     The embodiment of the edges  4 - 5  shown in  FIGS. 4 and 6  furthermore has the specific features of the fourth aspect of the invention described in the introduction, namely that: 
     the horizontally active interlock system of the second pair of edges  4 - 5  comprises contact faces  26 - 27  formed between the upwardly pointing locking element  13  and the downwardly pointing locking element  16 , wherein these contact faces  13  extend from bottom to top in a direction away from said first locking zone C 1 , wherein the contact faces  26 - 27  enclose an angle A 2  with the vertical from 1° to 10°. 
     It is noted that the coupling parts on the edges  2 - 3  and/or  4 - 5  are preferably configured such that in the coupled state, a so-called pretension is created which presses the coupled floor panels  1  towards each other, preferably with their upper edges towards and against each other. It is clear that the feature of the so-called pretension may be applied in all embodiments of floor panels according to the invention as described above or below. Such a pretension may be implemented in various ways, and preferably results from a stress force which in coupled state is generated by elastic bending and/or compression, wherein the return force thus generated ensures that the floor panels are pressed towards each other. Such a bending may be obtained by the coupling parts  8  and  9  in reality having slightly overlapping contours, or in other words profiled cross-sections. 
     As shown, it is preferred that the contact faces  26 - 27  and/or  29 - 30  are largely flat. 
     According to another advantageous feature, the tangent T 1  determined by said first locking zone C 1  forms an angle A 3  with the horizontal which is less than 60°, preferably less than 45°, and preferably less than 25°. Such a small angle provides a better engagement. 
     Such values for the angle A 3  may also be used in combination with the other aspects of the invention insofar as not conflicting. 
     According to a preferred feature, the tangent T 2  determined by said second locking zone C 2  forms an angle A 4  with the horizontal which is less than 60°, preferably less than 45° or, as shown in the examples, less than 35°. 
     Preferably, the angle A 4  is greater than the angle A 3 , and preferably at least 5° or at least 10° greater. 
     It is clear that the locking element  13  or at least the respective contact face  27  thereof may be tiltable or otherwise flexible. This tiltability may be implemented in any suitable fashion. Preferably, for this the recess  33  is provided on the underside of the floor panel  1 , but other techniques are not excluded. The tiltability may for example also be obtained due to elasticity in the material. 
     It is further pointed out that the floor panel from  FIGS. 1 to 6  has the following properties: 
     the coupling parts  6 - 7  and  8 - 9  are configured on the floor panel  1  such that the several of such floor panels  1  can be installed following the fold-down principle;
 
the floor panel  1  is oblong rectangular, and the first pair of mutually opposing edges  2 - 3  forms the long sides of the floor panel  1  while the second pair of mutually opposing edges  4 - 5  forms the short sides of the floor panel  1 ;
 
the coupling parts  8 - 9  on the second pair of edges  4 - 5  may be joined together via a downward snap movement M;
 
the coupling parts on the first and/or second pair of edges are largely configured as profiles in the material of the floor panel, preferably largely or completely by means of material-removal machining, preferably by means of one or more milling operations, for example with milling cutters which are active at different working angles, and even more particularly milling cutters for which during use the rotational axis is located outside the floor panel;
 
the coupling parts on the first and/or second pair of edges are configured as millable profiles which can be milled with milling cutters with a rotational axis which is located outside the floor panels during milling;
 
said male part  17  may or may not be split; preferably, as shown here, the male part is solid. According to an alternative, the male part is not however solid and contains one or more cavities or recesses, wherein it may for example be split, wherein the presence of such cavities or recesses offers the advantage that the locking parts are able to be more elastically movable; either the one or the other possibility may be selected depending on the material used and/or as a function of the desired locking effect;
 
only one male part, which may or may not be split, is applied to the second pair of edges; the bottom hook-shaped part  10 , and more particularly the lip  12  thereof, can be elastically bent and/or elastically deformed;
 
a space S 2  is present below the male part, adjacent to the vertically active contact faces  29 - 30 ;
 
the two contact faces of the first locking zone C 1 , including any extensions thereof, viewed in cross-section, extend to both the left and the right of the respective closure plane P, wherein the closure plane P is defined as a vertical plane through the upper edges  32  of the coupled floor panels  1  or the place where the floor panels  1  come together at the top;
 
the centre point of the first locking zone C 1  situated higher than the centre point of the second locking zone C 2 
 
the coupling parts on the first pair of edges and/or on the second pair of edges are completely integrally made of the material of the floor panel  1 , more particularly from a substrate which forms part of the floor panel;
 
the distal end of the top hook-shaped part above said first locking zone C 1  is completely free from downwardly active support points, or at least free from support points which, in coupled state, define tangents which make an angle with a horizontal of less than 45°;
 
the coupling parts on the second pair of edges are free from hook &amp; loop closures and/or glue connections;
 
on the first and/or second pair of edges, the floor panel is provided with chamfers  37 , such as bevelled edges;
 
the floor panel has a decorative top layer  38  which extends integrally from the horizontal top surface of the floor panel up to the chamfers  37 ;
 
the floor panels have a substrate  39  which may or may not be multipiece, and which may or may not consist of several substrate layers, wherein the substrate or, in the case of several layers, at least one of the substrate layers consists of a material which fulfils one or more or any combination of the following features, insofar as such a combination does not contain any conflicting features: plastic-based material, foamed or not foamed, resilient or hard, with or without plasticizer, filled or not filled with a wood-based or bamboo-based material for example in the form of fibres, chips, dust or sawdust, and/or filled with other substances e.g. chalk, lime, talc, ground stone-based fillers;
 
plastic-based material which is foamed with fine pores so that the majority of the plastic-based material contains pores and/or gas inclusions with dimensions of less than 1 mm, preferably less than 0.1 mm and even more preferably less than 0.01 mm, which means that the majority of the volume of the material concerned has no larger pores, and/or that on average the pores comply with said dimensions;
 
plastic-based material which is obtained by extruding plastic-based raw material in the form of sheet material, wherein in a preferred embodiment this material is foamed, this in turn preferably has fine pores which are such that the majority of the plastic-based material, as stated, contains pores and/or gas inclusions with dimensions of less than 1 mm, preferably less than 0.1 mm and even more preferably less than 0.01 mm;
 
plastic-based material which is obtained by spreading plastic-based raw material, which may or may not be combined with other materials, by means of a spreading process and consolidating this into the form of sheet material under the influence of pressure and in some cases increased temperature, wherein in a preferred embodiment the resulting material is foamed, this in turn preferably has fine pores which are such that the majority of the plastic-based material, as stated, contains pores and/or gas inclusions with dimensions of less than 1 mm, preferably less than 0.1 mm and even more preferably less than 0.01 mm;
 
plastic consisting of or based on or containing one of the following materials: PP, PE, PET, PUR, PVC, PIR or other suitable plastics;
 
plastic-based material with plasticizers, wherein the plastic-based material is preferably selected from the material stated in the preceding paragraph;
 
wood-based material, for example MDF, HDF, prefabricated wood panels, more particularly so-called engineered wood panels, where applicable with adapted core or end strips, wherein in the latter case preferably the coupling part  6  and/or the coupling part  7  is produced in the adapted core or adapted end strip; the term “adapted” means that with respect to a conventional panel, an adapted material is used for the core or for one or more end strips which is more suitable for creation of the coupling parts  8  and/or  9  therein;
 
the floor panel is configured as one of the following types:
 
a laminate floor panel;
 
a so-called resilient floor panel;
 
an LVT panel or CVT panel or comparable panel based on a plastic other than vinyl;
 
a floor panel with a first plastic-based, preferably foamed substrate layer, and thereon a preferably thinner second substrate layer made of or based on vinyl or another plastic;
 
a floor panel with a hard plastic-based substrate.
 
     It is noted that said vertically active interlock system VL and horizontally active interlock system HL of the first pair of edges  2 - 3  may be implemented in any fashion. Preferably, as shown here in  FIG. 5  for the vertically active interlock system VL, use is made of a tongue  40  and a groove  41 , which groove is preferably delimited by a bottom lip  42  and a top lip  43 . For the horizontally active interlock system, use is made of the locking parts  44  and  45  arranged on the tongue and groove, which engage in each other in coupled state. Here preferably the bottom lip  42  extends distally past the top lip  43 , and the locking part  45  also has a locking surface  46  which is situated past the distal end of the top lip  43 . 
     The term “tangent” according to the invention may be interpreted in a number of different ways. In general, it means a line which is tangential between two co-operating contact faces; the place where this tangent is considered may be arbitrary, but normally it is regarded in a central position, or the global tangent is thus considered unless defined otherwise. Alternatively, according to this application, the term “tangent” may also be replaced by the direction of the cooperating contact faces or the mean or global direction or global tangent thereof. 
     It is furthermore pointed out that the terms “distal side of the male part” and “proximal side of the female part” normally also include the extensions of the sides up to the top of the floor panel. 
     The terms “contact faces” and “locking zones” may also mean a linear contact; a contact face or locking zone is essentially the place where the actual contact is created in coupled state and under load where applicable. Where the text mentions “extensions of contact faces”, this means the actual continuations of the planes as well as a specific location where the actual contact exists. In this case, this is not an extension which is theoretically not present. 
     The term “coupling parts which are mainly made of the material of the floor panel” means that at least the essential constituents thereof are formed integrally from the material of the floor panel, and that at least all locking parts and locking elements are made integrally from the material of the floor panel. In other words, this means that there are no separate locking strips such as elastically bendable locking strips (for example as known under the names “Multifit” or “5G” or the like). This does not for example exclude that the coupling parts used according to the invention may be provided with a coating or similar. It also does not exclude that the coupling parts are formed integrally in edge portions which consist of a particular choice of material and are included in the edges of the substrate of the floor panel, as known for example from the production of so-called engineered wood panels. 
     The references V and H refer to the vertical and horizontal directions. 
     It is clear that the invention may be used at least with oblong rectangular and square floor panels, both with conventional laying patterns and with specific laying patterns, for example herringbone patterns. 
     The invention may be used both for relatively thin floor panels for forming a floor covering, for example of 4 mm or thinner, and with thicker floor panels. 
     The embodiment shown in the figures furthermore has the feature that a play, or in other words a space, is present between the locking parts  19 - 21  of the first locking zone C 1 . In the example shown, such a space is also present between the locking parts  18 - 20  of the second locking zone C 2 . These spaces are not necessarily present, but it is preferred that they are present in at least one of the first locking zone C 1  and second locking zone C 2 . If present in both locking zones C 1 -C 2 , then the space at the location of the second locking zone C 2 , viewed in the vertical direction, is preferably larger than the space at the location of the first locking zone C 1 . Preferably, the space at the location of the first locking zone C 1 , in the vertical direction, is less than 0.2 mm, preferably 0.1 mm or less, such as for example around 0.05 mm. In this way, the possible height differences between the coupled edges are limited. In addition, the presence of the chamfers  37  may to some extent mask such minor height differences. A space if present at the location of the second locking zone C 2  may, as stated, be designed larger, for example with a dimension in the vertical direction of more than 0.05 mm, preferably of around 0.1 mm or larger, preferably however less than 0.25 mm. 
     The spaces between the different locking zones C 1 -C 2  increase the ease of installation and have little or no influence on the quality of the connection. Any larger space at the location of the second locking zone may offer room for a possible residual tilting of the upwardly pointing locking element  13 . 
     It is also pointed out that the second locking zone C 2  has an added value for loading of the connection both in the horizontal direction H and in the vertical direction V. In both cases, the locking zone C 2  however results in some blocking of the tilt movement of the upwardly pointing locking element  13 . 
     Preferably, as shown, no space is formed between the contact faces  26 - 27  of the horizontal interlock system. In other words, a lock is achieved in the horizontal direction H which is free from play, and as stated may even have a pretension. 
     The present invention is in no sense restricted to the examples described above and shown in the figures, but such floor panels may be produced in different variants without leaving the scope of the present invention.