WO99/23328 PCT/GB98/03267 -1 DECORATIVE COVING INFILL AND SYSTEM FOR MOUNTING SANE This invention relates to decorative coving infills and a system for mounting same. More particularly the invention relates to coving infills of the kind disclosed 5 in our prior-published European patent EP 0 541 866 B which discloses a decorative coving infill which is adapted to be mounted as a decorative enhancement of an in-place coving system mounted at the ceiling/wall interface or junction in a domestic or possibly commercial 10 decoration system. The coving infill enables redecoration to be performed so that a tired or shabby or otherwise unsatisfactory coving system can be redecorated and/or enhanced or otherwise improved without the need to remove or replace the existing coving system, and thus without 15 the attendant problems of clean removal of the existing coving and/or associated removal of small areas of wall or ceiling plaster and/or the problem of non-removal from wall or ceiling of small portions of coving material. The coving infill system of our prior European patent provides 20 a simple and direct system in which a decorative coving infill is provided with a suitably profiled curved rear surface for face-to-face cooperation with the corresponding lengthwise extending curved face of the coving itself for adhesion thereto by means of zones or 25 stripes of adhesive material applied to the rear face of the coving infill. This system enables the professional or amateur decorator quickly to mount a coving infill system against the curved surface of the existing coving, thereby providing a fresh and clean (and if necessary 30 suitably decoratively profiled) coving surface for reception of paint or any other surface treatment which may be desirable. It has come to our attention that it would be an appreciable enhancement of the versatility of our prior- WO99/23328 PCT/GB98/03267 -2 published coving infill if it could also be used for direct use as an original or primary coving material which is suitable for direct attachment to the relevant surfaces of the wall and ceiling, and that its adhesive system was 5 not limited in application to the curved surfaces of existing in-place coving systems. However, the application of our prior coving infill system for existing walls and ceilings as a primary coving system leads to the technical difficulty that the 10 interaction of the curved rear surface of the coving infill with the generally planar faces of the wall and ceiling leads to a line contact adhesion zone. This is not sufficiently broad in terms of adhesion zone width for there to be an adequate adhesive effect in order to 15 achieve the desired contact adhesion which enables the professional or amateur decorator to mount the replacement coving at a practical rate and which meets the need for adhesive retention of the coving infill reasonably quickly upon location against the relevant supporting surface. 20 Initial retention by means of panel pins or other retaining means may be provided to hold the coving infill in place initially. To the best of the Applicants' knowledge there has not been previously proposed a coving infill system in 25 which a multi-function capability is provided enabling adequate adhesion to both the curved profile of an existing primary coving system and the generally planar surfaces of wall and ceiling where the coving is to be used not as an infill but as a primary coving system 30 itself. An object of the present invention is to provide a coving infill system including a coving infill construction together with an associated method of use offering improvements in relation to use in primary and 35 secondary coving applications and offering improvements WO99/23328 PCT/GB98/03267 -3 in relation to the identified desirable enhancement of existing coving systems and/or improvements generally in such coving systems. The invention provides a system of primary and 5 secondary (or infill) coving and a method of utilising the same, including systems for adhesive application and adhesive accommodation as defined in the accompanying claims. In an embodiment of the invention there is provided 10 a multi-function coving infill having a curved cross sectional profile at its rear surface for cooperation with a complementary curved profile of existing in-situ coving. In the embodiment, the coving infill is provided with twin-track lengthwise-extending profile-matching and 15 adhesive-receiving channels or grooves, these channels or grooves being respectively spaced from each other and at least slightly inwardly from the lengthwise edges of the infill itself to provide (when furnished with a suitable volume of adhesive) dual-function adhesive zones adapted 20 to adhere optionally to said existing in-situ primary coving or to the relevant surfaces of wall and ceiling in the absence of such primary coving. Thus, in the embodiment, the provision of the twin track adhesive-receiving channels suitably spaced from 25 each other and from the edge of the coving enables even the relatively unskilled user to provide, by simple nozzle-application of an adhesive composition of the usual gelatinous viscosity of such adhesive compositions, a twin-zone adhesion system which is so located relative to 30 the geometrical parameters imposed by the generally tangential relationship between the curved rear face of the coving and firstly the wall/ceiling surfaces and secondly the complementary curved surface of the primary coving (if present), so that adequate zonal (rather than 35 line-based) adhesion is obtained.
WO99/23328 PCT/GB98/03267 -4 In the embodiment it is of significance that whereas adhesion between complementarily-profiled curved surfaces is relatively readily provided between the infill and the primary coving even though the exact radii of curvature 5 may not exactly match, the same is not true in terms of providing zonal adhesion between a surface tending to make tangential contact with a planar surface, and the embodiment of the invention solves this technical problem by the expedient of an adhesive channel which provides 10 mechanical location of the otherwise dynamically unstable (in terms of positional location) nozzle-applied adhesive, and by virtue of the viscosity characteristics of the adhesive which enable a temporarily slightly protruding profile of the adhesive to enable accommodation by the 15 assembly of the geometrical implications of cooperation with both planar surfaces (at right angles), and complementary (or nearly complementary) curved profile surfaces. The user of the system quickly appreciates that the adhesive-receiving channels provide their optimum 20 adhesive zone function when provided with that amount of adhesive composition from the application nozzle which produces a longitudinally extending body or bead of adhesive which fills the minor volume of the channel itself and provides a small degree of outward projection 25 (whether of curved generally convex profile or irregular or other profile) so that an adhesive contact zone is formed and when the coving or infill is offered-up to its intended supporting surface there is provided a bonding zone corresponding with, approximately, the width of each 30 of the channels. Initial retention by means of panel pins or other retaining means may be provided to hold the coving infill in place initially. An important aspect of the invention relates to the location of the adhesive-receiving grooves or channels in 35 relation to the structure of the coving infill or coving WO99/23328 PCT/GB98/03267 -5 body. Thus, on the rear face of the coving infill or body, which faces the wall-ceiling interface in use, the grooves or channels are formed in the region of the longitudinal edges of the coving infill or body and extend 5 lengthwise thereof. The grooves or channels are spaced inwardly from their respective longitudinal edges by a dimension which has significance in relation to the function of the coving infill or body in that it serves partly to define a structural shoulder which, in use, 10 provides a significant structural interface between the coving infill or coving body and the primary coving or wall-ceiling interface to which it is adhered. In addition, the inward spacing dimension of the adhesive receiving groove or channel (or the first one thereof in 15 the case where there are two or more), serves to define the location, in use, of the adhesive in relation to the geometry of the coving/wall-ceiling structure, so that the dual functionality of the coving infill or body can be achieved. 20 In practice, due to the considerable variation in the actual physical dimensions of coving used in buildings of different sizes, the actual dimensional value of the inward spacing is not of particularly significance in general term. However, the inward spacing can be related 25 to the width dimension of the adjacent groove or channel. Generally the inward spacing of the groove or channel from the adjacent longitudinal edge of the coving infill or body (measured from that edge to the adjacent edge of the groove or channel) is at least half the width dimension 30 of said groove or channel and preferably from 0.5 to 2.0 times the width of the groove or channel. In this way the geometrical relationship of the channel and the adjacent (but spaced-from) longitudinal edge of the coving infill or coving body produces the 35 required functional and geometric relationship needed to WO99/23328 PCT/GB98/03267 -6 achieve the multi-functionality capabilities of the coving system. More specifically, the location of the grooves or channels are such that the shoulder portion of the coving 5 (as seen in cross section) is defined between one of the grooves or channels (the outer one if there are more than two at each edge of the coving), and the respective adjacent longitudinal edge of the coving. Each shoulder portion of the coving defines on its 10 outer (rear) face a longitudinal edge region of the rear face of the coving body, and the shoulder portion defines along its inner longitudinal edge, the outer longitudinal edge of its respective groove or channel. As a result the shoulder stands proud of the base region of the groove or 15 channel to form an abutment for face-to-face engagement with a wall-and-ceiling structure, or with the primary coving. Such face-to-face engagement is firstly to define at least in part the position of the coving body in use (when adhered to the wall-and-ceiling structure or 20 coving), and secondly to define an adhesive-limiting structure which serves to confine at least the majority of adhesive in the outward flow direction when initially supplied to the groove or channel, and which serves to be able to cooperate with the wall-and-ceiling structure in 25 defining a wedge-shaped adhesive-receiving zone in which the adhesive can at least initially extend beyond said channel to exert a bonding effect. An embodiment of the invention will now be described by way of example with reference to the accompanying 30 drawings in which : Fig 1 shows in pre-assembly spaced-apart positional relationship a primary coving product together with an associated secondary or coving-infill product as disclosed in our prior EP specification; 35 Fig 2 shows the assembly of Fig 2 in its adhered and WO99/23328 PCT/GB98/03267 -7 assembled condition; Fig 3 shows the coving infill product of Figs 1 and 2 as modified in accordance with the teachings of the present invention incorporating longitudinally-extending 5 channels or grooves into which adhesive is shown being extruded in the form of linear beads of adhesive; and Fig 4 shows a rear elevation view of the coving product of Fig 3; and Fig 5 shows a front perspective view of the same 10 product showing the location of the adhesive-receiving grooves or channels; Fig 6 shows the product of Figs 3 to 5 mounted in relation to a wall-and-ceiling assembly and serving as a primary coving product; 15 Figs 7 and 8 show, in views similar to that of Fig 6, the use of a second embodiment of the invention, incorporating twin adhesive-receiving grooves or channels at each longitudinal edge, being used (Fig 7) in relation to primary coving and (Fig 8) in relation to a wall-and 20 ceiling structure not having primary coving; and Fig 9 shows, on a larger scale an embodiment similar to that of Figs 7 and 8 and incorporating twin grooves or channels at each edge, and showing the dimensional relationship between the grooves or channels and an 25 adjacent shoulder of the coving. Figs 1 and 2 show an assembly as disclosed in our prior-published specification EP 0 541 866 Al. This assembly comprises a primary coving product 10 formed of conventional coving material and having a generally 30 arcuate form and constructed to be mounted in the usual way at the interface between a vertical wall surface and a corresponding horizontal ceiling surface. For simplicity of illustration, the tangential face-to-face contact between coving product 10 and the wall and ceiling 35 surfaces is indicated by broken lines 12 and 14 WO99/23328 PCT/GB98/03267 -8 respectively at the rear face 16 of coving product 10. The inner or front face 18 provides its decorative and decoratable surface when initially installed as a primary coving product, and serving the usual function of 5 decoratively blending the wall and ceiling surfaces without the need for detailed decorative attention to the line junction between these. As Fig 1 shows, primary coving product 10 is of generally arcuate format, extending longitudinally the 10 full length of the wall/ceiling interface along its lengthwise-extending edges 20, 22 which are of generally uniform thickness and separated by the arcuate front and rear faces 18 and 16 respectively. Primary coving 10 may differ somewhat in detail from 15 that which is shown in Figs 1 and 2 in terms of its thickness and radius of curvature and arcuate extent, but generally the primary coving 10 provides a longitudinally extending arcuate profile to receive (in due course after a period of use) the secondary or infill coving product 20 24 in the manner shown in Figs 1 and 2, such longitudinally-extending concave profile being provided at least in the edge regions 26 and 28 of primary coving 10. Secondary or infill coving 24 comprises a body of 25 coving material such as plaster or a suitable polymeric material, whether with filler materials or otherwise, and has a decorative front or inner side 30 and a non decorative rear or outer side 32 which is adapted, at least in its edge regions 34, 36 to co-operate with the 30 corresponding edge regions 26 and 28 of primary coving 10, as will be more fully described below. The front or inner side of secondary coving 24 is shown in Figs 1 and 2 as having a decorative profile. Any one of a number of different such profiles may be 35 provided, or indeed a relatively plain face may be WO99/23328 PCT/GB98/03267 -9 provided for the purpose of suitable treatment either when installed or in due course with suitable decorative treatments including emulsion paint or otherwise. Rear or outer side 32 of secondary or infill coving 5 24 has longitudinally-extending outwardly-facing convex curved surface regions 38 and 40 to serve as bonding zones for the reception of a suitable plaster adhesive spread lengthwise thereover to effect secure mounting of infill coving 24 to primary coving 10 in the manner shown in Fig 10 2. In this embodiment the remainder 42 of the rear side 32 of secondary coving 24 is generally planar so that it forms (as viewed longitudinally, as may be perceived in Fig 2) generally a chord with respect to the arcuate front 15 or inner surface 18 of primary coving 10. Alternatively, rear side portion 42 of secondary coving 24 may be convexly curved to fully or almost fully fill the concave region defined by the inner face 18 of primary coving 10, or may have a different profile. 20 The above description in relation to Figs 1 and 2 relates to a first embodiment of the present invention which is further described in relation to Figs 3 to 6 below. The drawings of Figs 1 and 2 correspond to those of our above-mentioned prior European specification EP 0 25 541 866 B. In Figs 1 and 2, the coving infill product 24, which is shown also in Figs 3 to 6 is shown without the provision of the grooves or channels in its edge regions 34, 36, in accordance with the present invention. Thus, 30 turning now to Figs 3 to 6, there are formed in the edge regions 34, 36 of coving product 24 twin-track lengthwise extending profile-matching and adhesive-receiving grooves or channels 44, 46, for a purpose to be described. Figs 3, 4, 5 and 6 illustrate the modification of 35 the coving infill product illustrated in our prior WO99/23328 PCT/GB98/03267 -10 published European specification in order to render it a multi-purpose coving product capable of optional use either as secondary coving in the manner indicated in Figs 1 and 2 or as primary coving as shown in Fig 6. For this 5 purpose there are provided in the convex curved regions 38 and 40 of coving 24 at these locations (so-chosen that they can perform the dual function described herein), the grooves or channels 44, 46 which perform, simultaneously, the function of adhesive retention and location means and 10 means for defining bonding zones applicable both to the primary (Fig 6) and secondary (Fig 2) coving functions. As shown in Figs 3 and 4, the grooves or channels 44, 46 extend generally parallel to each other and parallel to the upper and lower edges of the coving 24 and 15 are of a base width of 3 to 7 millimetres. The grooves/channels are of generally triangular cross sectional shape, having inwardly converging side walls. It would be possible to have a base groove/channel width of less than 3 millimetres (say 2 millimetres) and greater 20 than 7 millimetres (up to about 10 millimetres) subject to the characteristics and cost of the adhesive to be used. The cross sectional shape of the grooves may vary from triangular, including square and curved and other shapes. An important factor in this regard is the bonding 25 strength and cost of the adhesive itself. It is envisaged that in most cases it will be necessary to provide initial support for the coving 24 in its installed position (Figs 2 and 6) until the relevant degree of adhesive setting has occurred, and for this purpose 30 temporary mechanical retention means is employed such as panel pins, the mode of use of which is well known to the person skilled in the art. As shown in Fig 3, a bead of adhesive 48 is introduced into grooves/channels 44/46 from an adhesive 35 source comprising the usual cartridge-format and trigger- WO99/23328 PCT/GB98/03267 -11 operated dispensing gun 50 having a nozzle 52, having an outer end width or diameter such as to be received in or partly received in the width of the grooves or channels 44, 46. In use, the volume of adhesive dispensed per unit 5 length of the channels or grooves 44, 46 is such that the bead 48 thereof stands at least slightly proud of the surfaces 38, 40 of the coving 24 so as to be well positioned for adhesive co-operation with the corresponding planar surfaces of a wall 54 and a ceiling 10 56 as shown in Fig 6, and likewise for optional alternative co-operation with the concave inner surface of primary coving 10, if so desired. In use, where a primary coving product, such as coving system 10, is in place, then the mode of use of 15 coving product 24 is as illustrated in Figs 1 and 2. In that application of product 24, its function is very similar to that described in our prior EP specification and the adhesive in the grooves or channels 44, 46 serves to bond the infill product to its primary coving to 20 achieve a similar result to the surface-located adhesive described in our prior EP specification. In the case of the use of coving product 24 as a primary coving system as illustrated in Fig 6, the bead or body of adhesive in the grooves 44, 46 serves and is 25 located so as to be capable of effectively bonding to ceiling and wall, as illustrated in Fig 6. In Figs 1 and 2 the location of the channels 44 has been indicated by broken line circles 58, 60, within which may be provided the grooves or channels, of cross-sectional shape chosen 30 according to the circumstances, which serve to provide an adhesive location and retention function as well as providing the positional definition with respect to the relatively nearby upper and lower end edges of the coving product. 35 Turning now to the embodiment of Figs 7 and 8, there WO99/23328 PCT/GB98/03267 -12 is shown in Fig 7 a wall 100 and ceiling 102 structure having secured thereto a longitudinally extending element of primary coving 104, together with an associated length or element 106 of secondary coving which is to be adhered 5 to the concave face 108 of primary coving 104. For this purpose, secondary coving 106 is provided with twin pairs of adhesive-receiving grooves or channels 110,112 and 114,116, these being spaced apart by a complementary convex portion 108 of secondary coving 106, 10 which is of the same radius of curvature as concave face 108 of primary coving 104. Secondary coving 106 has a decorative outer face 120. Fig 8 shows secondary coving 106 mounted in relating 15 to the same wall-and-ceiling structure 100,102, but in this case the coving 106 is directly mounted on the wall and-ceiling surfaces without an intermediate coving element. As clearly shown in Fig 8, in use the adhesive 20 applied to the grooves or channels 110 and 116 forms two outwardly-extending profiles or beads 122, 124 which are located in wedge-shaped or tapering spaces defined between the edges of the coving body and the wall-ceiling structure, whereby the coving is securely and directly 25 adhered in place. As can be clearly seen in Fig 8, in the case where the coving 106 is to be used, not as secondary coving in relation to primary coving 104, but as primary coving itself in which the coving 106 is directly adhered to the 30 wall 100-ceiling 102 structure, then the adhesive beads which extend lengthwise of the grooves or channels 110, 112, 114 and 116 are of more liberal dimensions so that there is produced, at least initially, a tapering moulded bond element 106, 108 (of adhesive) at each 35 longitudinally-extending peripheral edge of the coving and WO99/23328 PCT/GB98/03267 -13 which exerts a substantial bonding effect in relation to the direct adhesion of the coving to the wall-ceiling structure. There can be seen in Figs 7 and 8 a shoulder member 5 130, 132 at each peripheral longitudinal edge of the covingelement 106, and these shoulder structures will now be discussed in more detail with reference to Fig 9 of the drawings. Fig 9 shows a multi-functional coving body 150 which 10 corresponds in its main constructional features with the coving body 106 of Figs 7 and 8 and parts corresponding to the parts described above of the embodiments of Figs 7 and 8 are numbered accordingly. Coving body 150 has a different decorated outer face 152 (having a dominant zig 15 zag profile as seen in cross-section) and there is also shown the optional relieved flat rear surface 154 to replace the convex portion 118 of the embodiment of Figs 7 and 8. In Fig 9 the width dimensions of grooves or channels 20 110 and 116 are indicated by dimension arrows 156 and the width dimension of shoulders 130 and 132 are likewise indicated by arrows 158. The dimensions are the same for both channels 110 and 116 (which are also equal in width to the inner channels or grooves 112 and 114), and 25 likewise both shoulders 130 and 132 have the same width dimension as each other. As can be seen in Fig 9, the shoulder width dimension 158 is appreciably larger than the channel width dimension 156 in the ratio of approximately 10 to 7 (10/7 30 = 1.43). In other embodiments, not illustrated, the ratio varies from 0.5 through 1.5 and up to 2.5, and even higher. The geometry relating to the location of the grooves or channels 110, 112, 114 and 116 is such that the shoulder portions 130, 132 (as seen in cross section) of 35 the coving body 150 are defined between the respective WO99/23328 PCT/GB98/03267 -14 ones (110 and 116) of the (outer) grooves or channels and the respective adjacent longitudinal edge 160, 162 of coving body 150. Shoulder portions 130, 132 define at their outer (or 5 rear) faces 164, 166 a longitudinal edge region of the rear face 118 of coving body 150, and the shoulder portions 130, 132 likewise define along their inner longitudinal edges 168, 170, the outer longitudinal edge of their respective grooves or channels 110, 116, so that 10 the shoulders 130, 132 stand proud of the base regions of the grooves or channels to form an abutment for face-to face engagement with the wall-and-ceiling structure 100, 102 or with the primary coving 104, firstly to define at least in part the position of the coving body 150 in use 15 (when adhered to the wall-and-ceiling structure and to the primary coving) and secondly to define an adhesive limiting structure which serves to confine at least the majority of adhesive in the outward flow direction when initially supplied to said grooves or channels, and to be 20 able to cooperate with said wall-and-ceiling structure in defining a wedge-shaped adhesive-receiving zone in which said adhesive can at least initially extend beyond said channel to exert a bonding effect. Adhesive is applied in the manner indicated in Fig 25 3 in a bead of width 6mm from a cartridge gun, and care is taken, in the case where the coving body is to be used as secondary coving, to confine the adhesive within the grooves or channels 110, 112 and 114, 116. However, in the case where the coving body is to be used as coving 30 body for direct adhesion to the wall-and-ceiling structure then significantly greater amounts of adhesive are applied in order to produce the bond elements 126,128 (see Fig 8). In use, panel pins may be employed to assist temporary location of the coving body, particularly when 35 used as secondary coving. The adhesive employed is WO99/23328 PCT/GB98/03267 -15 preferably of the kind which has relatively rapid tack or adhesion-producing capability whereby the procedure for mounting comprises initial offering-up of the coving body, firmly pressing same into position and then pulling back 5 for sufficient time (depending on the particular adhesive used) for tack development, followed by pressing the coving body into position with immediate adhesion assisted by modest numbers of panel pins if deemed beneficial. Amongst other modifications which could be made in the 10 above embodiments while remaining within the scope of the following claims are: a) modification of the cross-sectional shape or profile and depth and width of the adhesive-receiving grooves or channels 110, 112, 114 and 116; 15 b) In the case where two or more grooves or channels are produced at each edge, the width of the intermediate shoulder 172, 174 may vary from the proportion shown in Fig 9 in accordance with particular requirements, or indeed the grooves or channels may adjoin each other; 20 c) In the case where the coving body is to be adhered to a primary coving body, the use of longitudinal grooves or channels intermediate the edge regions of the secondary coving body may be beneficial; and d) Many other modifications to the geometric proportions 25 and materials employed in the multi-functional primary/secondary coving body.