INTERLOCKABLE SURFACE COVERING ELEMENT

Abstract: An interlockable surface covering element comprises a first planar portion (1) and a second planar portion (2) arranged to provide a series of interlockable protrusions and undercuts which may be used to connect together a number of elements into an interlocked array. One planar portion has a circular envelope and is divided into six sectors, each alternate sector (3, 4, 5) being a re-entrant of the same radius. The second planar portion is a hexagon. The elements are generally made of wood and can be interconnected in the manner of parquet to provide an interlocked surface covering.

Description: "INTERLOCKABLE SURFACE COVERING ELEMENT" FIELD OF THE INVENTION The invention provides an interlockable surface covering element of generally circular shape which can be fitted and interlocked with other such elements to provide a complete surface covering having no gaps. In particular, the element is preferably formed from rounds of wood which may be fitted together in the manner of parquet. PRIOR ART Parquetry and other surface covering materials have been used as floor and wall coverings in many forms and sizes. To avoid the wood raising and buckling, parquet is commonly interlocked by means of a tongue and groove construction. Other surface covering elements such as tiles are generally cemented in place. The elements have been provided in a variety of shapes, such as squares, rectangles, hexagons, diamonds etc., the shape being dictated by the need to cover the surface completely without leaving any gaps. Circular elements cannot be used alone since when abutted they leave generally triangular shaped gaps. MM OF THE INVENTION It is the aim of the present invention to provide an interlockable surface covering element of generally circular shape but which can be fitted and interlocked with other such elements to provide a surface covering without gaps. SUMMARY OF THE INVENTION The invention provides an interlockable surface covering element for interlocking with other such elements to completely cover the surface, which comprises: a first planar portion on one side of the element and extending partway through the thickness of the element; and a second planar portion on the other side of the element and extending partway through the thickness of the element; each planar portion having a shape of threefold rotational symmetry about a central axis perpendicular thereto, the shape being capable of fitting together with other such shapes without leaving any gaps; and the first and second planar portions being in such relationship to each other as to provide interlockable protrusions and undercuts, whereby the element can be interlocked into an array with othe such elements. Thus, the elements have protrusions and undercuts so that they may be interlocked together (in the manner of a tongue and groove interlock) so as to prevent lifting or buckling of the elements of the array. Generally, one or both planar portions are generally circular and have an outer periphery whose envelope has a radius r. the periphery being divided into 6 sectors each of 60° and each alternate sector being re-entrant and also having a radius r. Thus, when elements are fitted together, the non-re-entrants of one element are accepted by the re-entrants of another element to create a complete covering without any gaps. By providing both planar portions in this shape but disposed 60° out of phase to one another, a series of interlockable protrusions and undercuts are provided. In another embodiment, the second planar portion may be a hexagon whose sides coincide with the sectors of the first planar portion. Although the thicknesses of the two portions may differ, it is generally convenient that each portion extend halfway through the thickness of the element. The array of elements can be used to provide a non-buckling wall or floor covering. In fact, it is not necessary to attach the array to a surface in order to maintain its integrity, since the interlocking of the elements provides an array which is self supporting. The element may be moulded from a ceramic or plastics material. The element may also be made from marble, stone, slate or brick. However, the construction is most appropriate for use with wood which may buckle as it expands and contracts under the effects of heat and moisture. The wood may be used with its grain running along the plane of the element. However, a particularly pleasing appearance is obtained by using rounds cut across a wooden log so as to exhibit the tree ring structure. Used in this way, there is need to remove only a minimal amount of wood from the circular round thereby minimising wastage. The interlocking nature of the elements also minimises the need for sanding the array to provide a smooth surface. DESCRIPTION OF PREFERRED EMBODIMENTS Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings wherein Figure 1 is a plan view of an element which is generally circular on one side and hexagonal on the other side. Figure 2 is an elevation in the direction shown. Figure 3 is a further elevation in the direction shown, Figure 4 is a further elevation in the direction shown. -4 - Figure 5 is a section along line A- A, Figure 6 is a section along line B-B, Figure 7 is a perspective view of the element. Figure 8 is a perspective view of an element which is generally circular on both sides, and Figure 9 shows how the elements may be fitted together. Figures 1 to 7 show an element which is generally circular on one side (having a series of lobes and re-entrants) and is hexagonal on the other side. The element comprises a first planar surface portion 1 and a second planar portion 2. The first planar portion is generally circular having an envelope of radius r and being divided into six sectors each of included angle 60°. The periphery of each alternate sector is a re-entrant 3, 4, 5 also of radius r; the other sectors being in the form of lobes 6, 7, 8. The first planar portion 1 extends halfway through the thickness of the element. The second planar portion 2 (which is underneath as viewed according to Figure ^ 1) is a hexagon concentric with the first planar portion and whose maximum diameter is 2r. The hexagon has six sides 10 to 15 which coincide with the six sectors of the first planar portion. Where a re-entrant 3, 4, 5 coincides with hexagon sides 10, 12, 14 an undercut is created. Where lobes 6, 7. 8 overlie hexagon sides 11, 13, 15 a protrusion is created. Since the configuration of the protrusions and undercuts is complementary, the elements may be fitted together. Figure 8 shows a further embodiment which has a circular envelope of lobes and re-entrants on both sides, the re-entrants 20. 2.1. 22 of the first planar portion 1 overlying the lobes 23. 24, 25 of the second planar portion 2. Thus, it differs from the first embodiment only- in that the second planar portion is generally circular rather than hexagonal. Figure 9 shows how the generally circular first planar portions of seven elements 30 to 36 according to the first embodiment may be fitted together to provide a surface free of gaps. For example lobe 41 fits neatly into re-entrant 40. On the underside, the hexagonal second planar portions fit neatly together in a hexagonal array. Element 36 is a typical element formed from a round of wood. It is locked in position by the surrounding elements 30 to 35 by means of the interlocking protrusions and undercuts. Thus, elements can be interlocked to provide either the circular pattern shown in Figure 9 or the reverse hexagonal array, thereby providing a choice of surface patterns.

Claims: CLAIMS : 1. An interlockable surface covering element for interlocking with other such elements to completely cover the surface, which comprises a first planar portion on one side of the element and extending partway through the thickness of the element, and a second planar portion on the other side of the element and extending partway through the thickness of. the element; each planar portion having a shape of threefold rotational symmetry about a central axis perpendicular thereto, the shape being capable of fitting together with other such shapes without leaving any gaps; and the first and second planar portions being in such relationship to each other as to provide interlockable protrusions and undercuts, whereby the element can be interlocked into an array with other such elements. 2. An element according to claim 1 wherein the first planar portion has an outer periphery whose envelope is circular of radius r. the periphery being divided into six sectors each of 60°, each alternate sector being re-entrant and also of radius *r; so as to form a shape which may be fitted with other such shapes without leaving any gaps. 3. An element according to claim 2 wherein the second planar portion has the same shape as the first planar portion; the first and second planar portions being concentric and at an angle of 60° to each other, whereby the re-entrants of one portion underlie the non-reentrants of the other portion. 4. An element according to claim 2 wherein the second planar portion is a hexagon which is concentric with the first planar potion and has a maximum diameter 2r. the six sides of the hexagon underlying the six sectors of the first planar portion. 5. An element according to claim 1 wherein each planar portion extends halfway through the thickness. 6. An element according to claim 1 which is a wooden floor-covering or wall-covering element. 7. An element according to any claim 5 formed from a round cut across a wooden log. 8. An element according to claim 1 which has been moulded from a ceramic or plastics material; or is formed of marble, stone, slate or brick. 9. An array of interlocked surface covering elements according to claim 1.

Inventors: PACAK JOHN, PACAK, JOHN
Applicants: PACAK JOHN, PACAK, JOHN
Application year: 1986
Main classification: E04F15
IPC codes: E04F13, E04F15