Patent Publication Number: US-10765268-B2

Title: Anti-slip surfaces

Description:
FIELD OF THE INVENTION 
     The present invention relates to anti-slip surfaces and articles having anti-slip surfaces. The invention relates particularly but not exclusively to articles of sanitary ware, such as shower trays, bath tubs, tiles and wet room flooring, with anti-slip surfaces. 
     BACKGROUND TO THE INVENTION 
     It is known to provide articles of sanitary ware, such as shower trays, with an anti-slip surface in the form a coating that gives a rough surface finish. However, such coatings tend to have a lifetime that is shorter than the lifetime of the article to which it is applied. Also, applying and re-applying the coating can be difficult and inconvenient. 
     It is also known to provide anti-slip surfaces in the form of spaced apart raised formations on the shower tray. In order to facilitate comfort, cleaning and manufacture, the formations are relatively large, rounded and widely spaced, which limits their anti-slip performance. In particular, known anti-slip surfaces of this type tend to fail to meet modern anti-slip standards, such as the pendulum coefficient of friction test defined by British Standard BS 7976: Parts 1-3, 2002 and A1, 2003. 
     It would be desirable to provide an anti-slip surface that is durable, exhibits high anti-slip properties and is relatively easy to clean. 
     SUMMARY OF THE INVENTION 
     A first aspect of the invention provides an article comprising at least one face having an anti-slip surface, the anti-slip surface comprising a plurality of spaced apart projections raised with respect to the respective face, said projections having a top surface and a side extending between said top surface and said respective face, and wherein each projection is shaped to have an angular edge between said top surface and said side, and wherein each projection has a height of between 0.5 mm and 1.5 mm and a top surface with an area of between 3 mm 2  and 64 mm 2 , adjacent projections being spaced apart by between 10 mm and 16 mm. 
     From a second aspect, the invention provides an article comprising at least one face having an anti-slip surface, the anti-slip surface comprising a plurality of spaced apart projections raised with respect to the respective face, said projections having a top surface and a side extending between said top surface and said respective face, and wherein each projection is shaped to have an angular edge between said top surface and said side, the side being shaped to flare outwardly at the base of the projection. Preferably, each projection has a height of between 0.5 mm and 1.5 mm and a top surface with an area of between 3 mm 2  and 64 mm 2 , adjacent projections being spaced apart by between 10 mm and 16 mm. 
     Preferably, said angular edge is right angled. 
     Preferably, said angular edge is annular, extending around the periphery of said top surface. 
     In preferred embodiments, at least a peripheral portion of, and preferably the whole of, said top surface is flat. 
     Typically, the side is shaped such that it is substantially perpendicular to the top surface at said edge. 
     Preferably said top surface is circular. 
     Advantageously the projections are rigid (non-deformable). The preferred projections do not deform in response to the weight of a user standing or stepping on the anti-slip surface. 
     In preferred embodiments the side is shaped to flare outwardly at the base of the projection. Typically at least a lower part of the side is curved in transverse cross-section flaring outwardly at the base of the projection. Optionally the side is curved from said the edge to the respective face. Advantageously, the transverse cross-sectional curvature of the side is such that the side is tangential to the top surface at the edge. The side may have a transverse cross-sectional curvature with a constant radius. The size of the constant radius may be the same as the height of the projection. In preferred embodiments, said radius is between 0.5 mm and 1 mm, more preferably between 0.6 mm and 0.9 mm, and is most preferably 0.75 mm. 
     In some embodiments, said side comprises an upper portion, which forms the edge and extends from the edge part way to the respective face, and a flared lower portion extending from said upper portion to said respective face, wherein said upper portion is substantially perpendicular with said top surface. Preferably said lower portion of the side has a transverse cross-sectional curvature with a constant radius. Preferably the size of the constant radius is the same as the height of the lower portion. In preferred embodiments said radius is between 0.15 mm and 0.35 mm, more preferably between 0.2 mm and 0.3 mm, and is most preferably 0.25 mm. 
     In preferred embodiments the overall height of each projection is between 0.6 mm and 0.9 mm, and is most preferably 0.75 mm. 
     In embodiments having said upper portion, the height of the upper portion is preferably between 0.3 mm and 0.7 mm, preferably between 0.4 mm and 0.6 mm, most preferably 0.5 mm. 
     In embodiments having said lower portion, the height of the lower portion is between 0.1 mm and 0.5 mm, more preferably between 0.15 mm and 0.35 mm, most preferably 0.25 mm. 
     Typically the area of the top surface is between 9 mm 2  and 36 mm 2 , most preferably being 20.25 mm 2 . In preferred embodiments said top surface is circular and has an area of between 3.14 mm 2  and 50.27 mm 2 , more preferably between 7.07 mm 2  and 28.27 mm 2 , the most preferred value being 15.90 mm 2 . 
     Preferably the projections are arranged in an array comprising rows and columns of said projections. It is preferred that said array is a regular array, preferably a regular rectangular array. 
     In preferred embodiments the spacing between adjacent projections, in particular the respective centre of adjacent projections, e.g. a centre point on the top surface, in any row or column is between 10 mm and 16 mm, more preferably between 11 mm and 13 mm, most preferably being 12 mm. 
     It is preferred that all of the projections in the array are of substantially uniform shape. 
     Preferably all of the projections in the array are of substantially uniform height. 
     Preferably all of the projections in the array are of substantially uniform size. 
     In preferred embodiments said projections are non-deformable. 
     It is preferred that said projections are integrally formed with said respective face. 
     In a preferred application said article is a tray for a shower or wet room. The tray has a face on which a user stands during use, the face being provided with said anti-slip surface. 
     Advantageously, said article is a moulded article, said projections being integrally formed, by moulding, with said at least one face. 
     From another aspect, the invention provides an anti-slip surface comprising a plurality of spaced apart projections raised with respect to the respective face, said projections having a top surface and a side extending between said top surface and said respective face, and wherein each projection is shaped to have an angular edge between said top surface and said side, and wherein, preferably, each projection has a height of between 0.5 mm and 1.5 mm and a top surface with an area of between 3 mm 2  and 64 mm 2 , adjacent projections being spaced apart by between 10 mm and 16 mm. 
     From a further aspect, the invention provides a tray for a shower or wet room, said tray comprising at least one face having an anti-slip surface, the anti-slip surface comprising
         a plurality of spaced apart projections raised with respect to the respective face, said projections having a top surface and a side extending between said top surface and said respective face,   wherein each projection has a height of between 0.5 mm and 1.5 mm and a top surface with an area of between 3 mm 2  and 64 mm 2 , adjacent projections being spaced apart by between 10 mm and 16 mm,
 
and wherein each projection is shaped to have an angular edge between said top surface and said side.
       

     Advantageously, the anti-slip surface exhibits high anti-slip properties while being comfortable and easy to clean. 
     Further advantageous aspects of the invention will be apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments and with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are now described by way of example and with reference to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a first embodiment of a shower tray having an anti-slip surface embodying one aspect of the invention; 
         FIG. 2  is plan view of the shower tray of  FIG. 1 ; 
         FIG. 3  is a sectional view of the shower tray of  FIG. 1 ; 
         FIG. 4  is an enlarged side view of part of the anti-slip surface of the shower tray of  FIG. 1 ; 
         FIG. 5  is an enlarged side view of a projection that is part of the anti-slip surface of the shower tray of  FIG. 1 ; 
         FIG. 6  is a perspective view of a second embodiment of a shower tray having an anti-slip surface embodying one aspect of the invention; 
         FIG. 7  is plan view of the shower tray of  FIG. 6 ; 
         FIG. 8  is a sectional view of the shower tray of  FIG. 6 ; 
         FIG. 9  is an enlarged side view of part of the anti-slip surface of the shower tray of  FIG. 6 ; and 
         FIG. 10  is an enlarged side view of a projection that is part of the anti-slip surface of the shower tray of  FIG. 6 ; 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to  FIGS. 1 to 5  of the drawings there is shown, generally indicated as  10 , an article with an anti-slip surface embodying one aspect of the invention. In the illustrated embodiment, the article  10  is a shower tray although it will be understood that the invention is not limited to shower trays. The shower tray  10  comprises a base  12  having an upper face  14  on which a user (not shown) stands when showering. The illustrated shower tray  10  comprises a lip  16  surrounding the upper face  14  although in other embodiments the lip may be omitted. Usually a drainage aperture  18  is provided in the base  12 , opening onto the upper face  14 . 
     The upper face  14  is provided with an anti-slip surface  20  comprising a plurality of spaced apart projections  22  that are raised with respect to the upper face  14 , typically such that they project substantially perpendicularly to the face  14 . The anti-slip surface  20  may cover all or part of the upper face  14 , as desired. Typically the anti-slip surface  20  is provided on substantially all of the area(s) that comes into contact with a user&#39;s feet during use. The projections  22  are preferably arranged in an array  21  comprising rows and columns of the projections  22 . The spacing between adjacent projections  22  in a respective row is preferably constant, i.e. the projections in any given row are evenly spaced. It is also preferred that the inter-projection spacing of each row is the same as for the other rows. The spacing between adjacent projections  22  in a respective column is preferably constant, i.e. the projections in any given column row are evenly spaced. It is also preferred that the inter-projection spacing of each column is the same as for the other columns. In preferred embodiments the inter-projection spacing is the same in the rows and the columns. The rows and columns preferably run perpendicularly to each other. Therefore, the preferred array  21  of projections comprises a regular array  21 , preferably a regular rectangular array  21 . It will be understood that while the projections  22  of the anti-slip surface may be arranged to form a rectangular array  21 , the overall shape of the anti-slip surface  20 , or more particularly the peripheral shape of the array  21 , need not be rectangular (as illustrated in  FIGS. 1 and 2 ). In alternative embodiments, the overall shape of the array  21  and/or of the surface  20  may take any other desired shape, e.g. rounded, circular, polygonal or irregular. In alternative embodiments, the rows and columns need not be perpendicular to each other; they may be offset to run obliquely with respect to each other. While a regular array  21  of projections  22  is preferred, in alternative embodiments the projections may be arranged irregularly, i.e. be irregularly spaced apart. 
     In preferred embodiments, the spacing between adjacent projections  22  is between 10 mm and 23 mm, more preferably between 11 mm and 19 mm. More particularly, it is preferred that the spacing between adjacent projections  22  in any row or column is between 10 mm and 16 mm, more preferably between 11 mm and 13 mm. The most preferred spacing between adjacent projections  22  in any row or column is 12 mm. Accordingly, the most preferred embodiments comprise an anti-slip surface  20  comprising a regular rectangular array  21  of projections  22 , each projection  22  being spaced apart from the, or each, adjacent projection in its respective row and column by 12 mm. While it is preferred that the projections  22  in the array  21  are regularly spaced apart, some embodiments may have irregular inter-projection spacing, the spacing preferably being within the ranges stipulated above. Optionally, the projections in part(s) of the array  21  may be regularly spaced apart while the projections in other part(s) of the array  21  may be irregularly spaced apart. The preferred spacing values provided above are intended to relate to the spacing of the respective centres of adjacent projections  22 , e.g. the spacing between respective projection centre points when viewed in plan. This is illustrated as spacing S in  FIG. 4 . The preferred spacing range values and preferred values are inclusive and are given to the nearest millimetre. In other embodiments, the inter-projections may be outside of the ranges given above. 
     Referring now in particular to  FIGS. 4 and 5 , the projections  22  are described in more detail. Each projection  22  has a top surface  24  that is preferably flat. It is preferred that the entire top surface  24  is flat although in alternative embodiments only part of the top surface  24  may be flat, in particular a peripheral part that runs around the edge of the top surface  24 . In any event, the preferred projection  22  has an angular edge  26 , i.e. an edge that is sharp or non-rounded, between the top surface  24  and the side  28  of the projection  22 . In preferred embodiments, the edge  26  is right angled, i.e. provides a right-angled corner at the intersection of the top surface  24  and the side. The provision of the angular edge  26  is facilitated by the flatness of the top surface  24 . Conveniently the top surface  24  is circular (i.e. when the projection  22  is viewed in plan as shown in  FIG. 2 ). In alternative embodiments, the top surface  24  may take other regular or irregular shapes that may be rounded or angular, e.g. oval, elliptical, polygonal. In any case, the angular edge  26  is preferably annular, extending around the entire periphery of the projection  22 . Similarly the side  28  is annular, extending around the projection. The shape of the side  28  (when viewed in plan) may vary depending on the shape of the top surface  24 , for example the side  28  may be circular in plan view in embodiments where the top surface  24  is circular. Typically, the top surface  24 , or at least its flat portion(s) as applicable, is disposed substantially parallel with the upper face  14  from which the projection  22  extends. 
     In preferred embodiments the diameter D of the top surface  24  is between 2 mm and 8 mm, preferably between 3 mm and 6 mm, and is most preferably 4.5 mm. More generally, these dimensions may be applied to the width of the top surface  24 , when measured in at least one axial direction and preferably both perpendicular axial directions. In some cases where the width is not the same or constant in each axial direction, it is preferred that the respective widths remain within the ranges provided above. In preferred embodiments the diameter D′ of the bottom  30  of the projection is between 4.5 mm and 10.5 mm, preferably between 5 mm and 7 mm, and is most preferably 6 mm. More generally, these dimensions may be applied to the width of the bottom  30 , when measured in at least one axial direction and preferably both perpendicular axial directions. In some cases where the width is not the same or constant in each axial direction, it is preferred that the respective widths remain within the ranges provided above. Therefore the preferred area of the top surface  24  is between 3 mm 2  and 64 mm 2 , more preferably between 9 mm 2  and 36 mm 2 . In the particularly preferred embodiment where the top surface  24  is circular, the preferred area of the top surface  24  is between 3.14 mm 2  and 50.27 mm 2 , more preferably between 7.07 mm 2  and 28.27 mm 2 , the most preferred value being 15.90 mm 2 . The preferred ranges provided above are inclusive and given to the nearest millimetre. The most preferred value is given to the nearest millimetre. 
     The height H of each projection  22  from the bottom  30  to the top 24 is preferably between 0.5 mm and 1.5 mm, more preferably between 0.6 mm and 0.9 mm, and is most preferably 0.75 mm. These range values are inclusive and given to the nearest tenth of a millimetre. The most preferred value is given to the nearest one hundredth of a millimetre. 
     The side  28  of the projection  22  extends between the bottom  30  and the top surface  24  and, together with the top surface  24 , forms the edge  26 . Advantageously, the side  28  is shaped such that it is substantially perpendicular to the top surface  24  at the edge  26 . It is preferred that the edge  26  is right angled (making an angle of 90° between the top surface  24  and the side  28 ). However, in some embodiments, the angle of the edge  26  made between the top surface  24  and the side  28  may be greater than 90° by a small amount, e.g. up to 5° although preferably by no more than 2°. 
     Advantageously, the side  28  flares outwardly in a direction from the top surface  24  to the bottom  30 . To this end the side  28 , or at least part of it, is preferably curved in transverse cross-section (i.e. taken in a plane perpendicular to the face  14  as shown in  FIG. 5 ), although the flared portion of the side  28  may alternatively have a straight cross-sectional profile extending obliquely to the face  14 . In any event the flared portion of the side is located at the base of the projection  22  such that it meets the face  14 . 
     In preferred embodiments, including the embodiment of  FIGS. 1 to 5 , the side  28  is curved from the edge  26  to the bottom  30 . The transverse cross-sectional curvature of the side  28  is preferably such that the side  28  is tangential to the top surface  24  at the edge  26  in order to provide the desired right-angled edge  26 . As can best be seen from  FIG. 5 , this is conveniently achieved by providing the side  28  with a cross-sectional curvature having a constant radius R. Preferably, the size of the constant radius R is the same as the height H of the projection  22 . In preferred embodiments the radius R is between 0.5 mm and 1 mm, more preferably between 0.6 mm and 0.9 mm, and is most preferably 0.75 mm. These range values are inclusive and given to the nearest tenth of a millimetre. The most preferred value is given to the nearest one hundredth of a millimetre. In alternative embodiments (not illustrated), the side  28  may be provided with a cross-sectional curvature having more than one radius. 
       FIGS. 6 to 10  illustrate an alternative embodiment of an article  110 , in particular a shower tray, having an anti-slip surface  120  in which like numerals are used to denote like parts an in respect of which the same or a similar description applies as made above in relation to the embodiment of  FIGS. 1 to 5  unless otherwise indicated. The anti-slip surface  120  comprises an array  121  of projections  122  provided on the upper face  114  of the tray  110 . The spacing, arrangement and height of the projections is preferably the same as described above for the array  21  of projections  22 . The shape and size of the top surface  124  is preferably also the same as described for the projections  22 . 
     The profile of the side  128  is similar to that of the side  28  in that it is shaped to be substantially perpendicular, preferably exactly perpendicular, to the top surface  124  at the edge  126 , and in that it flares outwardly in a direction from the top surface  124  to the bottom  130 , the flared portion being located at the base of the projection such that it meets with the face  114 . 
     In this embodiment, the side  128  includes an upper portion  128 A, which forms the edge  126  and extends from the edge  126  part way towards the bottom  130 , that is substantially perpendicular, preferably perpendicular, to the top surface  124  (or at least to the flat portion of the top surface at the edge in cases where the top surface is not entirely flat). In preferred embodiments the upper portion  128 A is also substantially perpendicular, preferably perpendicular, to the upper face  114 . 
     The side  128  includes a lower portion  128 B extending between the upper portion  128 A and the bottom  130  that flares outwardly in a direction from the top surface  124  to the bottom  130 . The lower portion  128 B is preferably curved in transverse cross-section (i.e. taken in a plane perpendicular to the face  114  as shown in  FIG. 10 ), but may alternatively be straight in transverse cross-section extending obliquely to the face  114 . 
     The overall height H of each projection  122  from the bottom  130  to the top 124 is preferably between 0.5 mm and 1 mm, more preferably between 0.6 mm and 0.9 mm, and is most preferably 0.75 mm. The respective heights of the lower and upper portions  128 A,  128 B may vary from embodiment to embodiment. In preferred embodiments the height H′ of the upper portion  128 A is between 0.3 mm and 0.7 mm, preferably between 0.4 mm and 0.6 mm, the most preferred value being 0.5 mm. Preferably the height of the lower portion  128 B (the difference between H and H′ as shown in  FIG. 10 ) is between 0.1 mm and 0.5 mm, more preferably between 0.15 mm and 0.35 mm, the most preferred value being 0.25 mm. These range values are inclusive and given to the nearest tenth or one hundredth of a millimetre as applicable. The most preferred value is given to the nearest one hundredth of a millimetre. 
     As can best be seen from  FIG. 10 , the curved lower portion  128 B is conveniently created by providing the lower portion of side  128  with a cross-sectional curvature having a constant radius R. Preferably, the size of the constant radius R is the same as the height of the lower portion  128 B. In preferred embodiments the radius R is between 0.15 mm and 0.35 mm, more preferably between 0.2 mm and 0.3 mm, and is most preferably 0.25 mm. These range values are inclusive and given to the nearest tenth or one hundredth of a millimetre as applicable. The most preferred value is given to the nearest one hundredth of a millimetre. In alternative embodiments (not illustrated), the lower portion  128 B of side  128  may be provided with a cross-sectional curvature having more than one radius. 
     In preferred embodiments each projection  22 ,  122  is symmetrical about an axis (not shown) running perpendicular to the face  14 ,  114  in which case its transverse cross-sectional profile (such as shown in  FIGS. 5 and 10 ) is the same around the projection  22 ,  122 . In alternative embodiments, the projections  22 ,  122  may not be axially symmetrical, although they may at least be symmetrical about one or more planes that are perpendicular to the face  14 , in which case the cross-sectional profile may not be constant around the whole of the projection. 
     In preferred embodiments, all of the projections  22 ,  122  in the array  21 ,  121  have the same shape and dimensions. More generally it is preferred that all of the projections  22 ,  122  in the array  21 ,  121  are substantially uniform in shape and dimensions. Alternatively however the shape and/or dimension(s) of the projections  22 ,  122  in the array  21 ,  121  may differ from each other (although preferably still falling within the respective ranges provided above). It is preferred that at least the overall height H of the projections  22 ,  122  in the array  21 ,  121  are the same. 
     In preferred embodiments, the projections  22 ,  122  are rigid, or non-deformable (at least in the context of the intended use of the article  10 ,  110 , e.g. in response to application of the weight of a user). The projections  22 ,  122  may be formed from any suitable material, typically from the same material that the article  10 ,  110  is formed from, e.g. a plastics, metallic, composite, rubber or stone based material including but not limited to acrylic, stone, resin stone, steel, ceramic, glass reinforced plastics (GRP). It is particularly preferred that the projections  22 ,  122  are integrally formed with the face  14 ,  114  of the article  10 ,  110 , preferably by any suitable conventional moulding manufacturing process. It will be apparent that depending on what the article  10 ,  110  is (e.g. in the case of tray, tile or mat), the projections  22 ,  122  may be co-formed with the article  10 ,  110  as a whole when the article is being manufactured. The projections  22 ,  122  are particularly suited for manufacture by moulding in order to obtain the desired shape and dimensions, and advantageously also the desired rigidity. In alternative embodiments, the array  21 ,  121  of projections  22 ,  122  may be formed on or in an article (such as a sheet, mat, plate or other substrate) that can be fixed to the upper surface of another article (such as a shower tray) to provide the anti-slip surface. 
     The anti-slip surface may be provided on any relevant surface(s) of an article typically an upper surface on which a user may stand, walk or run, of any other suitable article, for example a tile, mat or other flooring article, or a bath, wet room tray or other sanitary ware article, usually on the in-use upper surface. More generally the invention is particularly suited for use with articles that tend to become wet during use, e.g. sanitary ware or flooring for use in or around pools, baths showers or the like. 
     It is found that anti-slip surfaces  20 ,  120  made in accordance with the invention exhibit high anti-slip properties and more particularly allow anti-slip standards such as British Standard BS 7976 to be met without causing discomfort to the user. In particular, preferred embodiments meet British Standard BS 7976: Parts 1-3, 2002 and A1, 2003. Advantageously, the provision of the flared portion at the bottom of the projections  22 ,  122  facilitates cleaning of the surface  20 ,  120 . 
     The invention is not limited to the embodiment(s) described herein but can be amended or modified without departing from the scope of the present invention.