WOOD TRIM SYSTEM

Abstract

For attaching wood trim around a door or window frame. In the disclosed system, plastic spline-clips attached to the jambs serve to fix the jamb to the wall. The spline-clips have two splines, which engage slots in the wood trim, forming a dovetail connection between the trim and the splines. The splines are elastic enough to deflect apart to admit the trim, and then spring back to grip the trim and to push the trim tightly against the wall. Grooves cut in the edge faces of the jambs receive lugs on the clips, by which the clips are accurately positioned on the jambs. Also disclosed is a split-jamb system, in which the inside jamb-frame is positioned first, then squared up in the wall opening, and then held in place on the wall by means of with its inside spline-clips; the outside jamb-frame is then assembled to the inside jamb-frame, and the outside jamb-frame locked in place with its outside spline-clips. Also disclosed is a corner-cover, which masks the ends of converging baseboards and other trim, on both inside corners and outside corners. The corner-cover avoids the need for mitring the baseboards. The corner-cover is profiled to fit the profile of the baseboard. Also disclosed is a system for attaching trim, e.g baseboards, chair rails, to a wall. This includes a hook-clip, the hook of which engages a slot cut in the trim. The hook is springy, and presses the trim against the wall. The system biases the trim so that it is the top of the trim that is pressed against the wall.

Description

This invention relates to trim, especially wood trim, of the kind as used in houses for finishing the edges and frames of doors and windows, chair rails, baseboards or skirting-boards, framing around panelling, and the like.

Examples will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional plan view of part of an opening in a wall, of a doorframe secured into that opening, and of a wood trim attachment system for use therewith.

FIG. 2 is the same view as FIG. 1, showing another trim attachment system.

FIG. 3 is a cross-sectional plan view of a whole doorframe, and opening, having the trim attachment system of FIG. 2, shown during a stage of assembly.

FIG. 4 is the same view as FIG. 3, but shows an alternative manner of assembly.

FIG. 5 is the same view as FIGS. 3,4 and shows the completed assembly.

FIG. 6 is a similar view to FIG. 5, but shows an another trim attachment system.

FIG. 7 is a view like FIG. 6, but shows the components partly assembled.

FIG. 7 a is a partly-exploded view of the components of the trim attachment system of FIG. 5.

FIG. 8 is a view like FIG. 7a of another trim attachment system.

FIG. 9 is pictorial view of a jamb-piece component of the system of FIG. 8, shown with spline-clip components attached.

FIG. 10 is a view like FIG. 8 of another trim attachment system.

FIG. 11 is a view of a corner of a room, in which two converging baseboards have been attached to the walls.

FIG. 12 is the same view as FIG. 11, except that a cover has been placed over the convergence of the baseboards.

FIG. 13 is the same view of the cover itself.

FIG. 14 is a view of the reverse or back side of the cover.

FIG. 15 is a plan view of the cover.

FIG. 16 is a side elevation of the cover.

FIG. 16 a is a side elevation of part of another cover.

FIG. 17 is a plan view of two baseboards converging on a corner of a room.

FIG. 18 is the same view as FIG. 17, except that a corner-cover has been placed over the convergence of the baseboards.

FIG. 19 is a side elevation of another corner-cover, placed over baseboards in a corner of a room.

FIG. 19 a is a close-up of an area of FIG. 19.

FIG. 20 is a view of an external corner of a room, in which a corner-cover has been placed over two converging baseboards.

FIG. 21 is a sectioned elevation of the foot of a wall and the floor of a house, showing a baseboard attached to the wall by a hook-clip system.

FIG. 22 is a close-up of part of the view of FIG. 1.

FIG. 22 a is the same view as FIG. 22 of a component of the system.

FIG. 22 b is the same view as FIG. 22 of another component of the system.

FIG. 23 is a similar view to FIG. 21 of another hook-clip system.

FIG. 24 is a pictorial view of hook-clips being installed on a wall.

FIG. 25 is an elevation of a chair rail attached to a wall using a hook-clip system.

FIG. 26 is the same view as FIG. 12, but shows a corner-cover in use with baseboards that have been attached by means of the system shown in FIG. 21.

The apparatuses and procedures shown in the accompanying drawings and described below are examples. The scope of the patent protection sought is defined by the accompanying claims, and not necessarily by specific features of the examples.

In this description, some of the components in the drawings have been given numerals with letter suffixes. The same numeral without the suffix is used to indicate the component generically.

FIG. 1 shows a basic installation, which makes use of some of the innovations described herein.

A door opening in a wall 21 includes a conventional upright two-by-four doorframe stud 23, to which sections of conventional drywall or plasterboard 25 are attached. A door jamb 27 fits across the width of the wall. Apart from its function as a component of the doorway, the jamb 27 serves to hide the unsightly stud 23, and to hide the cut ends of the plasterboards 25.

The jamb 27 has a surface 29 which, being visible, should be finished in a suitable manner, using e.g stain, varnish, paint, etc. The jamb 27 may be of a solid decorative wood, such as oak, or may be e.g fibre board, or solid particle board, to which a decorative veneer might be applied at least to the visible surface 29. The system as described herein applies when the jamb is made from other wood-based materials, or even from (e.g recycled) plastic materials. It is also known to make door jambs from bent/folded sheet metal, and the system is applicable in that case too, provided provision can be made for attaching the clip to the jamb.

The jamb 27 is supported and secured with respect to the wall 21 by means of spline-clips 30i,30o (collectively 30). The spline-clips 30 are formed as plastic extrusions, having an extruded profile as shown in FIG. 1. The profile of the spline-clip includes a web 32, which straddles across the gap between the edge 34 of the jamb 27 and the surface of the plasterboard 25 of the wall 21. A lug 36 protrudes from the web 32, and serves as a location stop, enabling the spline-clip 30 to be positioned correctly with respect to the jamb 27. A jamb-staple 38 is used to attach the spline-clip 30 immovably to the jamb 27. A wall-staple 40 is used, likewise, to attach the spline-clip 30 to the wall 21. With the inside and outside spline-clips 30i,30o bridging their respective gaps between the jamb 27 and the wall 21, it will be understood that the inside and outside spline-clips 30i,30o, when stapled in place, serve to hold the jamb 27 immovably with respect to the wall 21.

To install the assembly as shown in FIG. 1, the following steps can be performed. First, the door 41 is fixed into the assembled doorframe of which the jamb 27 is a component. (Often, the door, when purchased, is already factory-assembled into the doorframe.) The door and doorframe sub-assembly is then presented into the opening in the wall 21. The outside spline-clips 30o are stapled to the jamb 27, but are not yet stapled to the wall 21. The outside spline-clips 30o are spaced one every forty or fifty cm, for example, over the heights of both the left and right sides of the door, and across the lintel. (Herein, the fasteners are described as staples, and that is the preferred choice. However, nails etc, and even screws, could be used.)

When all the outside spline-clips 30o are properly stapled to the jamb 27, now the installer makes a final check as to the positions of the door jambs and lintel. When they are square and true, within the door opening, now the wall staples 40 can be applied. Now, the doorframe stands secured, square and true, at least as to its outside, to the wall 21. It is usually possible for a reasonably skilled installer to perform the task, without assistance, of securing a door and doorframe into the wall opening, with a perfectly acceptable degree of accuracy, in just a minute or two.

It cannot be ruled out that an installer might leave the jambs not quite vertical, or otherwise not perform the door installation properly—but, so long as the installer is not over-casual, and has the right tools to do the job, the installer can leave every door they install square and true, repeatably, in very short order, by the use of the spline-clips in the manner as described.

The same steps can now be performed with respect to the other side (the inside) of the door. That is to say, the inside spline-clips 30i are now stapled to the inside edge 34i of the jamb 27. Again, the lug 36 is used to position the clip correctly with respect to the jamb. With all the spline-clips 30i attached to the jamb 27, and with the installer checking once again, now from the inside, that everything is square and true, the spline-clips 30i can be stapled to the wall.

Now, as shown in FIG. 1, the jamb 27 is secured to the wall 21, both inside and outside, by means of the stapled spline-clips 30, and is held in place very rigidly and securely—as of course it is required to be, since the jamb 27 provides all the support for the door 41 and its operational movements.

The task of squaring up the door and doorframe within the door opening in the wall is thus accomplished very quickly and easily. And the installer, with a minimum of skill and attention, has been able to ensure that the installation is square and true. The installer preferably should pre-attach the outside spline-clips 30o to the jamb 27, but should not pre-attach the inside spline-clips 30i (or vice versa, if the door is to be installed from the inside). It would be impossible (or at least very awkward) to assemble the door and frame into the opening in the wall if both the inside and the outside spline-clips were pre-attached.

Now, with the installation of the spline-clips 30 finished, the installer can turn to assembling the wood trim. The trim 43 is formed with a profile as shown in FIG. 1, having two sloping slots, and the middle cut away to accommodate the web of the clip. As shown in respect of the inside of the door, in FIG. 1, the jamb-spline-slot 43 of the wood trim is placed over the jamb-spline 47 of the spline-clip 30.

At the other end of the wood trim 43, the wall-spline 49 of the spline-clip 30 is snagged on the entry to the wall-spline slot 50 of the wood trim 43. Now, if the installer pushes the wood trim 43 towards the wall 21, the entry-chamfer 52 on the end of the wall-spline 49 directs the wall-spline 49 to bend (leftwards, in FIG. 1), thereby enabling the wall-spline 49 to enter the wall-spline-slot 50. Thus, installation of the wood trim is a simple two-step operation for the installer; first, the wood trim is positioned so the jamb-spline 47 is entered into the jamb-spline-slot 45; then, the installer simply taps or strikes the wood trim 43 towards the wall, by hand, whereby the wall-spline 49 enters the wall-spline-slot 50.

It will be understood that the two jamb pieces and the lintel that make up the doorframe are manufactured in-factory, and are accurately cut and finished. (The bottom ends of the left and right jambs might have to be trimmed by the installer in some cases, but that is a task that requires very little skill and attention from the installer.) Equally, the wood trim pieces 43 are factory-cut and finished, including the mitres thereof, whereby again no craft-type skill is required on the part of the installer.

It will be understood also that no nails or other fasteners are required in respect of the wood trim pieces themselves. The wood trim can be quickly and accurately installed by a non-skilled person. There is no need for patching or other remediation, such as filling, sanding, painting, etc, of any kind, to be done after installation. All required finishing of the trim can be done in-factory—although it is not ruled out, of course, that painting etc might be done after installation. It will also be noted that the trim can be removed, in the future, if desired, and then re-fitted, all by hand, in order to facilitate the task of painting, for example, or applying wallpaper to, the walls.

Many home-owners want to make use of a decorative hardwood, not only for the trim 43, but also for the jambs 27 and lintel. To cater for such customers, the jamb and lintels, together with the required six pieces of wood trim 43 (two upright-pieces and one cross-piece, both inside and outside the door) and the associated spline-clips 30, may be done up for sale as a kit. It is also helpful for customers to be able to purchase a set of the three pieces of wood trim, and an appropriate set of spline-clips, as required to trim one side of a door. The pieces again are factory-made and finished (including mitred corners).

The door itself might or might not be included in a kit. It is customary for doors to be manufactured to very tight tolerances as to dimensions, squareness, and so on. This fact means that it is possible to sell the kits containing the jambs, trim, etc, separately from the doors, knowing that the kit will be bound to accurately fit any door of the nominal size for which it has been prepared. Thus, the designer really can arrange for the wood trim pieces, in the kit, to be mitred in-factory, whereby the mitres can be done perfectly accurately, and completely finished, before being added to the kit. This leaves the installer with the task of simply pressing the wood trim pieces into place, and the job is finished.

In the above-described cases, the system of spline-clips and trim can in fact be used with already existing doors and jambs. Thus, a kit comprising just the (pre-mitred and pre-finished) wood trim, without the jambs and lintel, may be offered for sale.

The following variant requires that the spline-clips be secured to the edges of the jamb using a groove in the jamb. As such, the following variant system cannot be used with jambs that have not been suitably grooved.

FIG. 2 shows another finished installation. Here, the spline-clip 60 has a barbed lug 61, which enters the prepared groove 63 in the edge 65 of the jamb 67. The groove 63 is a tight fit over the barbed lug 61, whereby no staples or other fasteners are needed in order to secure the spline-clip 60 to the jamb 67.

Now, the installer lines up the door and doorframe with the opening in the wall, and, when all is square and true, staples the spline-clips 60 to the wall in the manner as previously described with reference to FIG. 1. It will be appreciated that, when the jamb 67 is secured by several of the spline-clips 60, the jamb 67 is now held with respect to the wall 21 no less securely and rigidly in FIG. 2 than was the case in FIG. 1.

FIGS. 3,4,5 show the preliminary stages of the assembly. In FIG. 3, the left and right outside spline-clips 60o1,60or have been inserted into the respective grooves 63 in the edges 65 of the jambs 67, and now the outside spline-clips 60ol,60or are being stapled to the wall. The left and right inside spline-clips 60il,60ir have not been inserted into their respective grooves during this phase, to enable the door and doorframe sub-assembly to be inserted into the opening, from the outside. Once the outside clips 60o have been stapled to the wall, now the inside clips 60i can be placed and tapped into their respective grooves 63, and stapled to the wall, in turn.

FIG. 4 shows a somewhat different manner of inserting the door and doorframe sub-assembly into the opening. Here, the inside and outside spline-clips 60oh,60ih at the hinge end of the door are inserted first. Now, it is a little more awkward to manoeuvre the door and doorframe sub-assembly into the opening, but it usually can be done. Once the inside and outside hinge end clips 60oh,60ih have been stapled to the wall, now the inside and outside clips at the handle end of the door can be inserted into their grooves, and stapled, in turn, to the wall.

FIG. 5 shows the finished assembly, arising from both the FIG. 3 and the FIG. 4 cases.

Whether the installer chooses to go with (preferred) FIG. 3 or the FIG. 4 installation sequence, the point is that the system of spline-clips as described is versatile enough to cope with both, and still yield an installation in which the door is secured perfectly adequately from the strength and rigidity standpoints, and perfectly adequately also from the accuracy of squareness standpoint, and yet the installation still requires only a minimal degree of skill and attention, and time, from the installer. This is even more true of the barbed lug 61 and groove 63 arrangement of FIGS. 3,4,5 than of the plain location lug 36 arrangement of FIG. 1. Once both the inside and the outside spline-clips are stapled to the wall, there is no tendency for the barbed lugs 61 to work loose from the grooves 63, even over many years of service. Of course, if the door were to be abused, e.g by repeated heavy slamming, no doubt some failure or partial failure might occur—but that is true of any door installation.

It is traditional for installers to insert tapered shims between the door jamb and the wall stud, whereby the jamb can be held solidly and securely with respect to the wall. An aspect of the installers traditional skill has been the art of selecting and placing suitable shims, within the very short time which is all that can be economically allocated for the task. If the installers have not got the shims quite right, in that allocated time, they tend to move on anyway to the next door installation, and poor door jamb shimming is all too common a fault in the building trade.

It will be understood that the system of spline-clips, as described herein, can do away with the need for shims and shimming, in many cases, and still the door jamb is secured to the wall just as, if not more, securely and rigidly than when shims were used. There is a shorter time per installation, and the installations are more nearly perfect, more often. In some jurisdictions, the provision of shims in door jambs is a code requirement, and in that case, the installer should of course provide them.

The spline-clips system, as described, does not preclude the use of shims. In fact, the use of the spline-clips system makes the task of shimming easier, in that the shims can be inserted after the door jambs have been secured to the wall. When using the spline-clips system, as described, some installers prefer to add shims at critical points, e.g around the door hinges and at the latch and at or near the mitred joints. Thus, the installer might shim above and below the hinge area.

Indeed, door installers often prefer to provide a shim actually behind the hinge, and then run a long screw through one of the hinge screw-holes, right through the jamb, the shim, and into the door stud 23. This measure couples the strength and rigidity of the stud to that of the jamb, at the critical points. If the installer were to insert such a long screw without shimming, that might cause the jamb to distort, and shimming is therefore recommended for the through-screw case. Again, the fact that the jambs (and the whole doorframe) are already fixed in place, as a result of using the spline-clips system, means that the shimming task is not even slightly onerous or skill-demanding. Of course, if shims are to be inserted, that must be done when the trim is not present.

In the further variant as shown in FIGS. 6,7,7a the jambs are each in two pieces. The completed split-jamb arrangement is shown in FIG. 6. The two pieces of the split-jamb may be termed the door piece or outside piece 70, and the inside piece 72. Both left and right jambs, and the lintel, are split in this way.

The outside and inside jamb pieces 70,72 are held together with a key 74, and the grooves 76 that receive the key correspond to the grooves 63 in the edges of the jambs that receive the barbed lugs 61 of the spline-clips 60. That is to say, the outside jamb pieces can be reversed, in that both edges of the outside jamb pieces are equally grooved. Likewise, the inside jamb pieces. This can be advantageous when it comes to a choice of fitting the door with the hinge end either to the left or to the right. The hinges, and the latch socket, can be built one into the left, and the other into the right, outside pieces of the jamb, which can easily be switched around if need be.

One of the benefits of the split-jamb arrangement is that it permits the spline-clips to be pre-assembled, in the factory, to all the jamb pieces. Indeed, the clips can be permanently secured into the grooves in the jamb pieces, in-factory, e.g with adhesive. (Of course, the wood trim 78 is kept separate (i.e is not pre-assembled), and is only assembled and tapped onto the spline-clips 60 once the clips have been stapled to the wall.)

There is an argument against pre-attaching the spline-clips to the jambs, which is that the resulting sub-assembly is of a form that might make it vulnerable to being damaged during shipping. For those who wish to avoid this danger, and ship the jambs and spline-clips separately, it is an advantageous aspect of the spline-clip system that the spline-clips are so easily assembled to the jambs by the installer, on the job—and not only easily, but in a manner whereby even an inept installer can hardly misplace or misalign the spline-clips on the jambs. Also for those who fear damage to the jambs during transit, the presence of the slots in the edges of the jambs means that suitable protectors can be easily fixed over the edges of the jambs.

FIG. 7 shows the first phase of assembly of the door and doorframe sub-assembly into the door opening in the wall. As before, an installer with little skill, and not much attention, can staple the door and doorframe sub-assembly into the opening, leaving the assembly square and true, more or less perfectly every time. It is a simple matter also for the installer then to assemble the inside pieces of the jambs, and staple their respective spline-clips also to the wall, to give the result as shown in FIG. 6.

FIG. 7 a shows a close-up of some of the components, and illustrates the assembly stages.

As mentioned, the split-jambs variant is advantageous because it enables all the spline-clips to be glued into, or to be otherwise pre-assembled to, their respective jamb-pieces, while enabling the two pieces of the jamb to be assembled into the opening in the wall from opposite sides of the wall.

The split-jamb variant is advantageous also because it accommodates walls of different thickness. Generally, in the case of a wall made from plasterboard panels secured over studs, the two opposite surfaces of wall are, for practical purposes, perfectly parallel. Thus, the thickness of the finished wall, around the door opening, is the same over the whole area of the wall surrounding the opening.

However, even though a given wall is (usually) consistent as to thickness, it does not follow that all walls, though made to the same nominal dimensions, have exactly the same thickness. Thus, jambs (and lintels) made in-factory to the nominal thickness, do not always exactly fit the actual wall. The split-jamb variant readily accommodates itself to walls that differ slightly in thickness.

The split-jamb variant, however, does not so easily accommodate variations of thickness within one particular wall. Plasterboard walls are commonly finished by taping over the joints and corners and nail/screw heads, and then applying filler compound to conceal the tape and heads. When the walls have been finished in this way, it is not uncommon for there to be slight thickness variations, i.e variations in the thickness of the grout. Usually, if a wall does vary in thickness, it does not do so in a regular manner, but rather the variations take the form of ripples.

In one common form of thickness-variation, the wall is of uniform thickness from top to bottom, except that at the very bottom of the wall, the filler compound is slightly thicker. The split-jamb variant of the spline-clip system, as described herein, cannot accommodate thickness bumps and ripples, as such; but it has been found that it can, in typical cases, substantially reduce the effects of those bumps and ripples, by halving, for example, the amplitude thereof.

FIG. 8 shows another variant. In FIG. 8, the extruded plastic spline-clip 80 is provided with a location-and-securement lug 81. The door jamb piece 83 is also provided with a location-and-securement groove 85. A toe 87 on the end of the lug 81 engages the groove 85. To permit assembly to the jamb piece, a spline-clip profiled as in FIG. 8 of course has to be distorted. (It might be possible to slide the clips lengthwise along the jamb pieces, but that is not preferred as they are (or they should be) a tight fit.) It is simple enough for the designer to provide that the distortion is small enough not to damage the clip, and yet is sufficient, once the toe 87 is in the groove 81, to render the spline-clip more or less completely permanently locked, mechanically, to the jamb piece 83—and to remain so even if the door were to be repeatedly and abusively slammed.

The use of a location-and-securement lug and groove, as in FIG. 8, is preferred for use with split-jambs, because, with split-jambs, the spline-clips 80 can be pre-attached to the jambs 83 in-factory, when it can be assured that the required distortions do not damage the clips (or the jambs). If the assembly of the spline-clips to the jambs is left to the installer, that task might be too troublesome and demanding, especially given the simplicity and foolproof ease that characterises the system as a whole.

The door jamb piece 83 of FIG. 8 is set up with the latch socket 89, as shown. The lower location-and-securement groove 85a is provided in order to enable the jamb piece with the latch socket in it to be reversed. Thus, the same jamb-piece can be used whether the door is to open on the left or on the right. The same applies to the complementary outside jamb-piece of the door-set, to which are attached the door hinges.

FIG. 9 shows a length of the outside jamb 83, with some spline-clips 80 pre-attached.

Another variant on the split-jamb theme is shown in FIG. 10. Here, there is no separate key, like 74, but rather, the function attributable to the key here is performed by a tongue 90 of the lower piece of the jamb. The doorstop is formed into the door piece 92 of the jamb.

Also shown in FIG. 10 is a variant on the manner of attaching the spline-clip 94 to the jamb. Again, a location-and-securement lug 87, with a toe 85, is fitted into a complementary groove in the jamb 92. The spline-clip includes a platform to the right of the lug 87, which rests on the edge 96 of the jamb, and serves to position and support the spline-clip with respect to the jamb. The spline-clip is secured to the jamb by means of staples 98 through the lug 87.

There is no access to the region from which the staple 98 is inserted, once the jamb has been assembled and applied to the wall, so a design in which a fastener passes through the lug 81 can only be used with split-jambs. If the jamb is in one unitary piece, at least the set of either the inside clips or the outside clips must be left to the installer to attach to the jamb, after the jamb has been positioned in the opening—and of course the staple 98 cannot be inserted at that stage.

The designer might wish to arrange the spline-clip to extend the full height of the door jamb, and the full width of the door lintel, as respective long lengths of the spline-clip extrusion. However, it is preferred that the spline-clips be in separate pieces, spaced some forty or fifty cm apart, as illustrated in FIG. 9.

Each individual spline-clip should be long enough to allow ample room for the staples or other fasteners that will secure them to the wall. Each piece of the spline-clip preferably should be about three cm long or more (“long” being in the direction of the extrusion), and about five cm long is preferred. Preferably, the spline-clip should be sized and dimensioned to encourage the installer to put the staples where they will enter the studs.

As to width, door trim mouldings vary as to their width, typically between about five and ten cm. The width of the spline-clip has to be less than the width of the trim, so as to leave respective engagement lands 101,103 (FIG. 7a) at the wall end and the jamb end of the trim. Apart from that, the spline-clip preferably should be as wide as the trim allows, for good stability and holding power.

The designer need not seek every scrap of width available, however, and a manufacturer of trim might prefer the emphasis that several different trim profiles all use a single spline-strip extrusion.

The designer should also see to it that the spline-clip profile is so dimensioned that the staples or other fasteners that are used to secure the trim to the wall are assured of passing into the door frame stud 23, and not into the space beyond. Securing the spline-clip to the plasterboard, rather than to the stud, is inadvisable.

The profile of the trim has to be matched to the profile of the spline strip (or vice versa). In fact, the profile of the spline strip imposes some limitations to the flexibility of design of the profile of the trim. Again referring to FIG. 7a, the central area 105 of the non-visible side of the trim has to be cut away, to provide room for the web portion 107 of the spline-clip 60. This is not difficult; in fact, there is typically ample room for the cut away area to be large enough for electrical wires (e.g speaker or telephone cables) to be run along the length of the trim, and thus pass around a door.

Preferably, the two splines (i.e the jamb-spline and the wall-spline) are positioned right at the very ends of the spline-clip. The splines on the spline-clip define a dovetail shape. It should be regarded that a male dovetail structure exists between the two spline slots in the wood trim, while the two splines on the spline-clip define a female dovetail structure.

It might be thought that it would be equivalent if the male and female roles were reversed; however, reversal of these roles is not preferred. If the wood trim were to form the female dovetail structure, the wood material between the slots would then be subjected to tensile stresses, rather than to the preferred compressive stress, which could lead to premature failure.

There is another reason also why it is advantageous for the splines on the spline-clip to be arranged as the female dovetail, which is that the female-dovetail splines, upon being urged apart by the presence of the male dovetail of the wood trim, insofar as the plastic spline-clip is flexible and capable of deflecting, tend to curl or rotate (slightly) into closer contact with the wall and with the jamb. This rotation of the ends of the spline-clip is desirable, because it urges a tighter degree of contact between the engagement lands 101,103 of the wood trim to the wall and to the jamb.

The profile of the plastic spline-clip is formed by extrusion, and therefore the designer is at liberty to call for re-entrant features, if desired. On the other hand, the wood trim profile is formed by cutting, using rotating saws, which practically forbids the formation of re-entrant shapes in the profile. The dovetail format, using flat-sided slots, is preferred because that shape enables forces to be exerted onto the wood trim, without having to resort to re-entrant features in the profile of the wood trim.

The flat-sided dovetail form is preferred also in that components can vary slightly dimensionally, due to tolerances, and the flat-sided dovetail form allows the springiness of the splines (or at least of the wall-spline) to maintain the force urging the wood trim against the wall and jamb, even though the dimensions of the components might vary slightly.

Even so, the requirement for accurate cutting of the wood trim is rather high, with the system as described herein, and the system should not be considered unless high tolerance standards can be assured and maintained during manufacture of the wood trim. However, using modern profile cutting machines, and with reasonably careful tool-setting, the required accuracy can be attained with reasonable ease. The flat-sided male-dovetail form contributes to this ease.

For economical cutting of the wood trim profile, preferably the axes of the rotating saws should be all vertical. That is to say, defining the direction of movement of the wood trim through the cutters as horizontal and north-south, the axes of all the cutters should appear to be vertical when viewed from east or west, and should all appear to be east-west when viewed from above the table. Preferably, the axes should be kept stationary, while the wood is being fed through the saws. The slots as required in the trim, in order to make use of the spline-clips system, are perfectly in keeping with this preference for economical cutting.

It is not required that the axes of the saws be all parallel when viewed from the north or south. Preferably, the two slots in the wood trim, as illustrated, are cut by saws the axes of which are angled mutually at the required mutual angle of the slots.

It is not necessary, in the spline-clip system, for the slots in the wood trim to be parallel-sided, i.e for the slots to be of constant width along their depth. However, making the slots parallel-sided does make for slightly simpler tooling and preparation of the cutting saws. Also, the bottoms of the slots need not be square with sharp corners, as illustrated; the sharper the bottom corners of the slots, the more there might be a problem of a premature crack starting at the (most stressed) corner.

The steeper the slope of the splines, the more they tend to urge their respective ends of the wood trim into contact with the wall and jamb. In fact, it is the slope of the wall of the slot in the wood trim, at the contact point, that determines the force with which the trim is held against the wall or jamb. The wall of the slot in the wood trim, at the point where contact is made between the wall and the engaging spline, lies at an angle with respect to a perpendicular to the plane of the wall. Preferably, the angle should be about ten degrees or more.

The angle AJ in respect of the jamb-spline-slot may be steeper than the angle AW in respect of the wall-spline-slot, since the jamb-spline does not have to deflect, or does not have to deflect as much as the wall-spline. More particularly, preferably the angle AJ should be about thirty degrees or more, while the angle AW preferably should be about twenty degrees or more.

As mentioned, the jamb-spline 49 is provided with a lead-in chamfer 52. As shown in FIG. 1, the jamb-spline 47 on the clip 30i receives the jamb-spline-slot 45 in the trim 43. During installation of the wood trim, it is required, as mentioned, that the wall-spline 49 should bend (i.e bend to the left in FIG. 1) when it is being is engaged by the corner of the wall-spline-slot 50. The lead-in chamfer 52 on the wall-spline 49 should be dimensioned such that the corner of the wall-slot 50 strikes the sloping surface of the lead-in chamfer, and not, for example, the very end of the wall-spline 49, which might cause the wall-spline simply to buckle.

There is no need for the jamb-spline, at the other end, to be formed with a corresponding lead-in chamfer. The jamb-spline 47 on the spline-clip 30 can be entered into the jamb-spline-slot 45 in the wood trim 43, by simple positioning of the wood trim 30i, as shown in FIG. 1, without needing the jamb-spline to bend or deflect.

Thus, the two splines perform different functions, and can be shaped differently to reflect this. Since the jamb-spline is not required to bend (although it is not detrimental if the jamb-spline can bend somewhat), the jamb-spline can be short and stumpy, while the wall-spline must be flexible enough (which means long and thin enough) to deflect far enough to permit installation without damage to the wall-spline.

The different roles as described for the deflection of the jamb-spline, and the non-deflection of the wall-spline, could be reversed. That is to say, the designer might arrange for the wood trim to be assembled wall-spline first, and then be tapped down onto the jamb-spline, rather than jamb-spine first, as shown.

As to both the jamb slot and the wall slot, in the wood trim, only one side of each slot is functionally effective, being the side of the slot that is closer to the other slot. The respective splines press against these functional sides of the slots, and the pressure urges the wall end of the wood trim firmly against the wall 21, and urges the jamb end of the wood trim firmly against the jamb 27.

The other sides of the slots in the wood trim are not contacted by their respective splines. In fact, the slots should be wide enough to ensure that such contact does not happen, since contact of the spline with both sides of the slot would probably make it impossible to assemble the wood trim to the spline-clip. Similarly, the designer should see to it that the tips of the splines cannot make contact with the bottoms of the slots. Apart from that, the slots should be as narrow and as shallow as possible, since the slots can only weaken the mechanical integrity of the wood trim profile.

Regarding the groove 76 (see FIG. 7a) in the edge of the jamb, preferably the groove should be in the middle of the edge of the jamb, for strength-in-symmetry reasons. The designer should also see to it that there is enough room for the jamb-end engagement land 103 to engage the remaining surface of the edge to the right of the groove, and that consideration might lead the designer to place the groove slightly to the left of centre of the jamb edge 34.

The groove in the edge of the jamb should preferably be parallel to the overall width of the jamb, i.e at right angles to the edge of the jamb; if the groove were to lie at an angle, forces acting on the jamb, e.g due to normal (and abnormal) operation of the door, might cause the barbed lug 61 to tend to ride out of the groove 76.

The material of the wood trim may be solid wood, having an attractive decorative grain, such as oak. Such woods tend to be strong, and resistive to cracks. However, cutting slots into what is inevitably a rather thin profile is bound to lead to an increased risk of cracking, especially during assembly (and dis-assembly, since it is a feature of the described trim-attachment system that the trim can be removed, e.g for the purposes of decorating the wall).

As mentioned, placing the female dovetail form in the (plastic) spline-clip, rather than the wood trim, minimises this increased risk. Still, the designer of the wood trim profile should see to it that an ample thickness of the wood material lies over and around the cut slots. Also, the type of wood should be selected in deference to the form or profile of the particular wood trim, and if a particularly-favoured profile should require the wood to be rather thin, over and around the slots, a wood that is especially resistant to cracking should be selected for that profile.

Even so, wood and wood products do have a tendency to split and crack, and it is an advantage of the system as described that the wood, though slotted, is substantially not subjected to forces which might tend to apply tensile stress to the corners of those slots.

On the other hand, if the material of the trim were, for example, plastic, there would be little point in employing the attachment system as described herein. Where trim is formed as a plastic extrusion, the extruded profile can readily be formed with intricate re-entrant features of shape, as can the spline-clips, such that really almost any shape would do to secure the profile. It is mainly because wood is so liable to split and to crack, when subjected to tensile stresses, that the system as described, with its avoidance of tensile stresses in the profile of the trim, is advantageous.

The same shortcoming that wood has, i.e its tendency to split and crack, is present also in many manufactured wood-based materials. Thus, manufactured materials such as particle board, and especially the fibre boards, are, like wood itself, also liable to split and crack if overstressed in tension. (Such materials are sometimes used as a base for trim profiles, often being wrapped with a veneer of a decorative wood). The layered-paper type of wood-like products are, if anything, even more likely to split and crack.

The system as described is most advantageous when used with materials that do indeed tend to split and crack if and when subjected to tensile stresses. Materials like (most) plastics and metals, by contrast, tend to stretch and yield when subjected to excessive tensile stress. The prior art is replete with attachment systems suitable for use with those non-crackable materials, which are highly unsuitable for use with wood and wood-based liable-to-split materials.

The system has been described herein as it applies to doors requiring wood trim on both sides, i.e both in the room inside the door, and in the room outside the door. In some cases, wood trim might only be required on one side of the door, e.g because the other side of the door faces an unfinished room. In that case, the installer should not seek to secure the jamb to the wall by placing the spline-clips just on the one side of the door.

One function of the spine clips, as described, is to support the jamb relative to the wall, and if spline-clips were provided just one side of the door, the door jamb would not have proper support. So, where it is desired to apply trim just to one side of the door, still the spline-clips should be provided on both sides of the door; either that, or the jambs (and lintel) could be shimmed in the conventional manner.

Although described for doors, the system can also be used for windows—especially in cases, again, where wood trim is required both inside and outside the window. This is not a common situation, however, in that usually the outside of a window is exposed to the elements.

The system can however be used advantageously with outside windows, in some cases. For new installations, the as-manufactured jamb of the windowframe can be provided with a groove, for receiving a key, e.g the kind of groove as shown in FIGS. 6,7a,8. FIG. 10a shows such a windowframe 110, having a groove 112.

It should be understood that the windowframe 110 is already secured into the opening in the wall, being shimmed and (rigidly) attached to the stud 23, in the conventional manner. FIG. 10a shows a key 74 entering the groove 112, as the jamb-piece 114 is being pressed outwards.

The spline-clip 60 is already secured into its groove in the split-jamb-piece 114. When the spline-clip 60 makes contact with the wall surface 116, the installer can then staple the spline-clip 60 to the wall. After that, it only remains for the installer to assemble and tap home the (already pre-mitred) wood trim onto the spline-clips, and the installation is finished.

This may be contrasted with what has to be done when wood trim is installed around a window in the conventional manner. Windowframes, though square and accurate as to their in-factory manufacture, after installation very rarely reside accurately straight and upright in the opening in the wall. In particular, the distance from the (grooved) inside edge 111 of the windowframe 110 to the inside surface 116 of the wall is not constant around the whole perimeter of the window.

Typically, when conventionally finishing a window, the installer first attaches jamb-pieces (similar to 114 in FIG. 10a) to the inside edges 111 all around the windowframe 110. These jamb-pieces extend inwards, the installer having seen to it that the pieces are cut so as to project inwards slightly beyond the wall surface 116. Next, the installer shaves down the projecting portions of the jamb-pieces 114 until their front edges are all flush with the inside surface of the wall, all around the window. Now, the installer has flat surfaces to which he can attach the wood trim.

By the use of the system as described, the front edges 115 of the split-jamb-pieces automatically align themselves flush and straight with the wall surface 116, simply as a consequence of the spline-clip 60 making contact with the wall-surface.

After installation, there will probably be a non-constant gap between the jamb-piece 114 and the windowframe 110. A piece of corner trim 117 readily conceals this gap.

The system can also be used with existing windowframes (which do not have grooves 112), as shown in FIG. 10b. Here, a separate grooved-strip 118 is first attached to the inside edge of the existing windowframe. Now, the jamb-piece 119, again with its spline clips 60 pre-attached to it, is inserted into the groove in the grooved-strip 118 attached to the windowframe. Installation of the jamb-pieces and spline-clips is completed by stapling the spline-clips to the wall, as before. Then, it only remains for the installer to finish the job by tapping home the pre-mitred wood trim.

It should be understood that this variant of the system, as described in relation to outside windows, can also be used for outside doors.

A craftsman carrying out the task of applying lengths of baseboard moulding at the foot of the walls of a room generally finds it a simple matter to apply long straight lengths of baseboard moulding to a long wall. The difficult part of the craftsman's task arises at the corners. Indeed, if it were not for the difficulties posed by the corners, the job would hardly require the skill and experience that merits the term “craftsman”.

Generally, at the corners of the room, the lengths of baseboard moulding have to be mitred together. Alternatively, one of the baseboards can be coped at its end to the profile of the other, but that too is a skill- and time-consuming task. The task of forming perfect mitres and copings is rendered the more difficult in that corners of rooms in houses are very rarely perfectly square. The craftsman knows, however, that the householder will not accept that badly-mitred baseboards can be excused because of the difficulties caused by the out-of-squareness of the walls. The craftsman is expected to produce perfect-looking mitres, in the baseboard mouldings, whatever the squareness condition of the corners of the walls of the room.

The degree of out-of-squareness of any one particular room corner is not predictable. Therefore, it is practically not possible for the mitred joints to be prepared ahead of time, e.g in a factory. Therefore, it falls to the craftsman himself, on the job, to assess the degree of out-of-squareness, and to assess the compensatory compound-angle cuts that will be required, and generally to determine just how best to match the ends of the baseboard mouldings so as to achieve the appearance of perfectly-mitred joints. And this task falls to the craftsman on the basis of starting afresh in every single corner of every single room.

FIG. 11 illustrates how the job of applying baseboard mouldings to a room could be hugely simplified, if only the ends of the baseboard mouldings could be left a little distance short of the (un-square) corner. If FIG. 11 were all that were required, the job of affixing baseboards could be left to the most inept, casual, unskilled, worker.

In the present case, it will be understood that, as far as the baseboards themselves are concerned, leaving the baseboards 120,121 short, as in FIG. 11, is, indeed, all that is required. The savings in labour costs—at craftsman rates—will be clearly apparent.

Of course, merely to leave the ends of the baseboards open, and uncovered, as in FIG. 11, is unsightly and unacceptable. FIG. 12 shows how the open ends of the baseboard mouldings may be effectively, and elegantly, concealed. The cover 123 is simply placed and secured into the corner, over the mouldings.

The cover 123 is shown in detail in FIGS. 13-16. The cover 123 is simply a shell, which has been moulded to fit over the baseboard mouldings 120,121. That is to say, the cover 123 is profiled to complement the profile of the particular baseboard moulding.

Another baseboard moulding profile would require a different profile of trim. However, this is not particularly onerous in terms of marketing and stock-keeping. A baseboard moulding stockist can only stock so many baseboard profiles, and it is a simple matter to locate respective boxes of corresponding covers alongside the stocks of the baseboards.

The cover 123 should be quite thin, as to its material thickness. However, it is recognised that, with a cover of the form as illustrated, it is not necessary to make the cover 123 so thin that the cover practically disappears when placed over the baseboard mouldings 120,121. It is recognised that, so long as the cover is roughly (or exactly) of the same appearance and finish as the baseboards themselves, the cover makes a decorative (though not obtrusive) feature of the corner. It is recognised that, without having to make the cover so thick and chunky as to be obtrusive, the designer has ample scope to specify an adequate thickness for the material of the cover, from the standpoint of strength and rigidity, without compromising appearance.

It is preferred that the cover be made out of wood, or wood products. Thus, the cover may be formed as a compression moulding, comprising wood chips in an adhesive matrix. Manufactured thus, a thickness of about one-and-a-half or two millimetres would give rise to a product having sufficient strength and resilience as to survive reasonably careful installation. The prudent installer would make sure to provide a number of spare covers, in case of accidental breakages. (Baseboard mouldings themselves are not completely free of the danger of breakage and spoilage, and the installer would provide some spare lengths of that, also.)

As may be seen in FIGS. 13-16, the cover 123 is (inevitably, given its function) of an awkward and fragile-seeming shape. The ability not to have to skimp on material thickness is important, given that shape.

The visible outer surface of the cover (seen in FIG. 13) can be painted to match the baseboard. Or, the visible outer surface can be wrapped with glued-on veneer, again to match the baseboard.

The cover 123 can alternatively be manufactured as a plastic injection-moulding. Now, the thickness can be reduced, e.g down to a minimum of about one-half millimetre, although one millimetre would be preferred.

A variant manner of manufacture of the cover, when it is done in plastic, would be as an extrusion. Now, the cover described herein would be formed as a mitred corner comprising two pieces of the extruded profile, glued together at a mitred joint. The mitred joint would be manufactured in-factory, whereby the joint could be perfectly aligned, and could be assured of being stronger than the extruded form itself.

Alternatively again, the cover could be manufactured as a pressing in sheet metal, and be thinner still. However, metal is less preferred, in that it can be difficult to procure a finish, in metal, that has the appearance of wood. That difficulty would not arise if the baseboards were to be painted, of course. On the other hand, metal ages and settles differently from wood, and a metal cover might be more likely to become obtrusive after a time.

As illustrated, the cover 123 is formed with an upper platform 125. The platform 125 is provided in order to serve the following function. It is all too common, especially in rooms in which the walls are plastered, for the profile of the intersection of two walls 129,130 to have the form as shown in FIG. 17. That is to say, even though the walls might be approximately at right angles, there is a bump 132 or bulge or promontory in one (or both) walls, right at the corner—due to a build-up of plaster in the corner. Such a bump 132 is especially likely to be present at the foot of the wall, i.e right where the baseboards 120,121 are to be installed. When such a bump is present, the task of producing a neatly-mitred corner joint is especially difficult.

The cover 123, with its platform 125, can ease this difficulty. First, the baseboard mouldings 120,121 are installed into the corner (that is to say, just short of the actual corner, as in FIG. 11). Then, the installer assembles the cover into the corner. Now, the bump or bulge 132 will prevent the platform from being installed to its full extent. The installer therefore notes which places along the edge of the platform 125 need to be trimmed back, in order to allow the cover 123 to fit snugly against the wall, around the whole corner.

It is a simple matter for the installer to remove those places on the thin material of the platform 125 of the cover 123 with a trimming knife, file, etc. In fact, the installer can very quickly learn how to trim the platforms 125 in this manner, and thereby can enable the cover 123 to fit reasonably perfectly into the corner, in just a few moments with a trimming knife or file. FIG. 18 shows how the platform 125 has been trimmed to exactly follow the profile of the bulge or bump 132.

It is also not unheard of for one of the walls at a corner to be indented at the corner, rather than to protrude. To cater for that case, the designer should provide for the platform 125 to overhang the profile of the baseboards, by a couple of millimetres.

As illustrated in FIG. 16, and in the alternative FIG. 16a, the material of the platform 125 itself is rather thinner than the main profile of the cover 123. This allows the installer to quickly cut or shave such material from the platform edges as might need to be removed.

FIG. 14 is a pictorial view of the back side of the cover 123, i.e the side that makes contact with the baseboards 120,121. It will be understood that the formed profile of the surfaces shown in FIG. 14 is a “negative” of the profile of the visible surface of the baseboards.

Provision for enabling the cover 123 to be adhered to the already-in-place baseboard mouldings 120,121 takes the form of the adhesive patches 136, as shown. The cover 123 is attached to the baseboards after the baseboards have been installed on the wall, and therefore the task of applying (or activating) the adhesive, falls to the installer. The adhesive patch preferably uses the type of glue that sticks on contact. Prior to application, the patch 136 is protected by a covering strip, which is removed just before (final) assembly of the cover into the corner, over the baseboards. The designer might specify the kind of glue that holds the corner-cover firmly to the baseboards, but yet allows the user to remove the corner-cover (by carefully pulling it off) from the baseboards. Some glues also are, upon the corner-cover being replaced, capable of re-sticking the corner-cover to the baseboards.

The designer might also wish to secure the corner-cover to the baseboards by driving a nail through the corner-cover, and into the studs of the wall, in the corner. However, this is not preferred, for a couple of reasons:—the nail holes would then have to be filled and finished; and the driving of the nail might cause distortion of the corner-cover, or might cause the material of the corner-cover (or of the baseboard) to split.

Other kinds of adhesive might be preferred. Instead of providing localised patches, the designer may prefer to provide adhesive over the whole area of the back (i.e the area visible in FIG. 14) of the cover. Two-part adhesives can be used, especially of the kind in which the part on the back of the cover is not sticky until activated, and the activator is in a form that the installer can apply to the face of the baseboards, just prior to assembly.

In the alternative of FIG. 19, shown in the close-up FIG. 19a, the cover 138 includes a layer 140 of resilient foam or other compressible material, applied to the back (i.e non-visible) surface of the outer cover 141. The outer cover 141 itself can be made of wood products (including solid wood), or plastic, or metal, and finished as appropriate. The layer 140 of soft material is about one millimetre thick or more. The compressible layer 140 assists conformance of the profile of the cover 138 to the profile of the baseboard 142, even if (slightly) mis-aligned.

Upon assembly of the cover, the thickness of the layer 140 would be visible between the material of the outer cover 141 and the baseboard 142. However, the foam may be suitably coloured, so the layer 140 is practically invisible—or rather camouflaged—when the cover 138 is in place. The presence of the layer 140 thus enables the cover to appear to fit perfectly to the baseboards 142,143 even in cases where there might be some slight mis-alignment.

The layer 140 is pre-glued inside the wood material of the outer cover 141, in-factory. The adhesive by which the layer 140, in turn, is adhered to the baseboards 142,143 is applied to the surface of the material of the layer, and again this adhesive is activated by the installer.

The covers as previously described were for internal corners. The described style of structure can also be used for external corners, as illustrated at 149 in FIG. 20. Again, the platform 150 on top of the cover may be quickly trimmed by the installer to conform to the actual shape of the corner 151 of the wall. (External corners of walls are even more likely than internal corners to be out of square, especially at the foot of the wall, where the baseboards 152,153 are located.) The details of the form of the external corner cover not shown in FIG. 20 correspond to those of the internal corners.

The two arms or limbs of the corner piece are set at right angles. The limbs should be equal in length. (There might be cases where the designer might wish to make the two limbs unequal in length, or to set the limbs at some angle other than a right angle. For example, a stockist might wish to make covers with the limbs set at 135° available as a stock item.

The lengths of the limbs would typically be three cm. Preferably, the limbs should not be less than about fifteen mm in length, or the cover could hardly be expected to fulfil its function of covering the ends of the baseboards; or, even if it did at least cover the ends of the baseboards, such short limbs might make installation requirous of almost as much craftsmanship as mitring the joints.

The limbs should preferably not be more than about six cm long, because covers longer than that would probably be regarded as too obtrusive. That is just an aesthetic aspect, however, since there is no technical reason why the limbs cannot be longer. The longer the limbs, also, the greater the possibility that covers in closely adjacent corners might interfere with each other.

As noted, one of the aspects of wall construction, in houses, is that the very bottoms of the walls tend to be provided with an abundance of filling compound, and to stand slightly proud of the surface of the rest of the wall. This is disadvantageous from the standpoint of conventional baseboards. If a baseboard were to stand even slightly away from the surface of the wall, the resulting gap is very noticeable and obtrusive; and a bulge at the foot of the wall has the effect of exacerbating such a gap between the wall and the top of the baseboard. Conventional installers therefore tend to cut the mitres between baseboards at a slight compound angle, so that the baseboards, at least at the corners, where the problem is likely to be worst, lie with the bottoms of the baseboards slightly further out from the wall than the tops of the baseboards. The use of the covers, as described, eliminates this aspect, as a practical problem.

FIG. 21 shows the foot of a wall of a room. The wall surface is formed by a sheet of plasterboard 160, which is screwed to a stud 161, attached to a sole plate 163, attached to the floor in the conventional manner. Carpet 164 is secured to the floor.

In the baseboard attachment system shown in FIG. 21, the baseboard 165 is formed with a slot or groove 167 (FIG. 22). The baseboard has a wall side and a room side 170 (which is visible from within the room), and the groove 167 is formed in the wall side. The groove 167 in the baseboard 165 is defined by a wall-facing surface 172 and a room-facing surface 174.

The system included a hook-clip 176. The hook-clip is formed as an extrusion in plastic, and its extruded profile is shown in FIG. 22. The profile includes a flat attachment-element 178, via which the clip is attached to the wall. The attachment-element 178 presents a fastener-receiving face when ready for attachment to the wall. Nails, staples 180, etc, can be driven through the attachment element 178, through the plasterboard 160, and into the stud 161 behind.

Above the attachment-element 178, the profile of the hook-clip 176 includes a hook-element, comprising a hook 181 and a hook-extender 183. Below the attachment-element 178, the profile of the hook-clip 176 includes a buffer-element, comprising a buffer 185 and a buffer-extender 187.

The hook-element is springy. The nominal (i.e unstressed) profile of the hook-clip 176, is shown in FIG. 22. Thus, in FIG. 22, the hook 181 of the hook-clip is shown interfering with the room-facing surface 174 of the baseboard 165. Thus, the hook element is forced, by the complementary shape and dimensions of the hook and of the room-facing surface 174, to bend in the direction into the room, away from the wall.

The surface of the hook 181 is indented, as shown, so that the hook can engage both sides of the groove 167, and not become jammed therebetween. The indentations or ripples mean that the baseboard is retained quite firmly on the hooks of the hook-clips, against accidental dislodgement, but the baseboard can be lifted off the clips without undue effort.

The buffer-element also is springy. Again, in FIG. 22, the buffer 185 of the hook-clip is shown interfering with the wall-facing surface 172 of the baseboard 165. Thus, the buffer element is forced, by the complementary shape and dimensions of the buffer 185 and of the wall-facing surface 172, to bend in the direction towards the wall.

The forces generated by bending the hook-element and the buffer-element are reacted against the baseboard 165. Together, the hook-force and the buffer-force produce a turning moment or couple or torque on the baseboard, urging the baseboard to rotate in a counter-clockwise direction. The baseboard 165 is, however, prevented from so rotating by the engagement of a land 189 against the surface of the plasterboard 160.

Thus, the resilience of the hook, and the resilience of the buffer, combine together to urge the baseboard into what can be regarded as a very tight contact between the top edge of the baseboard and the wall. It is recognised that this tight contact is very effective in creating a very good appearance of the baseboard relative to the wall.

With conventional baseboard attachment systems, it is all too common for gaps to appear between the baseboard and the wall. Even though very small, these gaps can be unsightly.

Because the force or pressure of the baseboard against the wall is the result of resilience, the system as described provides some margin whereby, even if the baseboard should change its position, or its size, slightly, still the top edge of the baseboard is pressed tightly against the wall surface.

And, of course, changes can take place in the dimensions of the components. Components of houses settle, dry out, shrink, warp, and undergo many other changes. Most of these are very small, but they can be enough to make the trim in a room, which appeared perfect when it was first installed, look rather shabby after a few years.

With the attachment system as described, however, such changes can be accommodated. The system makes it possible for the changes to take place, but not to lead to any tiny, but unsightly, gaps. What happens is that the baseboard rotates slightly (counter-clockwise in FIG. 21), whereby the very top of the baseboard remains pressed firmly against the wall. The change of angle of the baseboard is substantially completely unnoticeable—by contrast with the described gaps, which, if they occur, can be very obtrusively noticeable.

On the other hand, if the baseboards are indeed allowed to rotate, the tendency is for any mitred joints between adjacent baseboards now to start to open up, at the bottom. However, combining the hook-clip system with the joint covers 123,149, as described, can mask such opening-up of the mitres that might result from a slight rotation of the baseboards.

The baseboard 170 is supported as to its height on the wall by the contact of a nose 190 of the baseboard onto the ledge formed by the hook extender 183. Preferably, the thing that defines the rest position of the baseboard should not be the engagement of the top of the hook 181 with the end of the groove 167, as that might interfere with the force arising from the hook element urging the baseboard towards the wall.

The baseboard is assembled over the hook-clips 176 simply by placing the baseboard flat against the wall, slightly above the clips, and then lowering the baseboard down until the nose 190 abuts the ledge 183. That is the end of the installation process. The chamfer 184 at the entrance to the groove 167 ensures that the hook 181 easily enters the groove.

To remove the baseboards, all that is required is to lift them off. When they are replaced, they immediately adopt the position whereby the tops of the baseboards are pressed firmly against the surface of the wall. This aspect is very convenient when it is desired to re-decorate the wall, either with paint or with a covering such as wallpaper.

The dimensions of the profile of the hook-clip 176 are important. The clip should be of such dimensions and form as to hold the baseboard firmly against the wall, so that the baseboard is not dislodged by everyday impacts thereagainst. The clip should not be so tight that the installer might find it difficult to assemble the baseboard over the clip.

The profile of the plastic hook-clip preferably should be between ½ mm and 2 mm thick. The distance apart of the hook element and the buffer element (as measured between their respective points of contact with the baseboard) should be between 2 cm and 6 cm. The top of the hook 181 should be between 1 cm and 5 cm below the very top of the baseboard.

It will be observed that the foot 192 of the baseboard 160 is not touching anything. Thus, if a person were to press against the foot of the baseboard, the baseboard would rotate—clockwise, in FIG. 21. When the pressure was released, the elements of the clip 176 being resilient, the baseboard would immediately rotate back, until the land 189 was once again pressed firmly against the wall.

It will be understood that, if the bottom of the baseboard were to be secured to the wall, that would prevent or impede the very top of the baseboard from pressing tightly against the wall. Thus, the absence of restraint at the bottom of the baseboard is in fact a contributory factor regarding the capability of the baseboard to move to rotate and thus to maintain the pressure of the top of the baseboard against the wall.

It is not required that there be no restraint at all, at the bottom of the baseboard, but rather that any restraint experienced by the bottom of the baseboard should be small. In the case as shown in FIG. 23, the carpet 164 has been replaced with tiles 192 (or other hard surface flooring). The presence of the carpet 164 meant that whatever gaps there might be between the bottom of the baseboard and the floor would be masked by the carpet. The use of tiles instead means that the gaps (if there are any—which there usually are) will therefore be visible and apparent. A channel-strip 194 serves to mask the gaps.

The channel-strip 194 exerts only a very small force tending to press the bottom of the baseboard against the wall. The profile of the channel-strip includes a long arm 196 that fits behind the baseboard 165, and the channel-strip is secured to the wall by means of staples 197 that lie at or near the top of the long arm.

Dimensioned and secured in this manner, the channel-strip really does not restrain the bottom of the baseboard from adopting its own position relative to the wall. At the same time, the channel-strip effectively does mask any gaps there might be between the bottom of the baseboard and the floor. Of course, the channel-strip is installed on the wall prior to the baseboard being installed. (If the channel-strip 194 were omitted at the time the baseboard was installed, it could easily be put in later, simply upon lifting the baseboard off the clips 176.)

FIG. 24 shows the clips 176 in the form of individual lengths (e.g five to ten cm) of extruded plastic. The task of positioning the clips on the wall at the correct height above the floor can be simplified in the manner as shown in FIG. 24. The installer rests a length of the baseboard on the floor, close to the wall, and makes a line 198 on the wall, along the top of the resting baseboard. The installer also prepares a spacer 200, which is of a width (i.e its height in FIG. 24) that, when the baseboard is set thereon, will position the baseboard so that the bottom of the baseboard just brushes the carpet 164. Holding the spacer 200 against the line on the wall, as shown, and holding the clip against the spacer, the installer then places a couple of staples through the clip and into the wall.

The installer might prefer to locate the clips 176 such that the staples go through into the stud 161 behind. Alternatively, the installer might prefer to locate the clips 176 between the studs such that the staples go through only the plasterboard 161.

This can be advantageous for the following reason. It often happens that plasterboard bends inwards slightly, between the studs. When the clips are placed between the studs, therefore, the clips can serve to draw the baseboard and the plasterboard together, in the areas between the studs, where the gaps would otherwise be largest.

The clips can be attached to the plasterboard by means of so-called expanding staples, which engage the remote or distal surface of the plasterboard, and thus draw the clip and plasterboard together very strongly. It may be noted that it is not practical to attach regular baseboard to plasterboard, between the studs, using expanding staples, because the heads of the staples are visibly highly obtrusive—but the heads are not visible when used on the clips.

FIG. 25 shows the use of an alternative hook-clip 205, shown here in connection with a chair rail 207 rather than a baseboard. Here, the buffer-element of the clip has been omitted. Thus, all the needed resilience now has to come from the hook 209 itself.

Now, because there is no buffer, the lower part of the chair rail 207 has to touch against something (in this case, against wainscot panels 210 attached to the wall) in order to provide a reaction to enable the forces arising from the hook 209 to be exerted upon the chair-rail 207. Particularly in the case of a chair rail, which is generally shorter in height than a baseboard, there can be enough resilience just in the hook to hold the chair rail firmly against the wall.

Also, there is more reason for wanting the bottom of a chair rail to touch the surface of the wall than there is for wanting the bottom of a baseboard to touch the surface of the wall. And, it should not be ruled out that, in some cases, the designer might be able to omit the buffer in the case also of a baseboard.

FIG. 26 shows the corner-cover 123 now used with baseboards 220,221 that have been attached to the wall using the system shown in FIG. 21. This use of the corner-covers can be especially advantageous for the following reasons.

The baseboard attachment system illustrated in FIG. 21 is aimed mainly at ensuring a tight fit between the top of the baseboard and the wall—i.e. at ensuring no gaps appear, even after a period of years, between the top of the baseboard and the wall. This on-going tight contact at the top of the baseboard is achieved, it can be regarded, at the expense of allowing the bottom of the baseboard to find its own position. That is to say, the springiness of the hook and of the buffer cause the baseboard to rock or rotate (slightly), if it needs to, in order to keep the top of the baseboard tight against the surface of the wall.

This rotation, if it occurs, could cause the mitres at the corners of converging pieces of the baseboard to open up, near the bottom of the baseboards. The designer might regard it as a pity if the excellent visual effect of the tight fit of the tops of the baseboards were to be marred by mitres that have cracked open; and fortunately this all-too-possible condition can be alleviated by using the corner-covers 123,149 at the corners, when the baseboards are attached by the FIG. 21 system.

In this specification, reference is made to walls having outside and inside surfaces. This is for identification. In the terminology of split-frame window or doorframes, the outside frame is typically the half of the frame in which the door or window is actually mounted, which is usually regarded is being towards the outside of the room. Outside with respect to one room is inside with respect to the other room, and, although the terms should be applied consistently, the use of the terms should not be regarded as being limiting in scope.

Claims

1. Procedure for fixing a doorframe or windowframe, termed a frame, in an opening in a wall, the wall have an inside surface and an outside surface, and for applying wood trim around the frame, including: providing an inside set of plastic spline-clips, each spline-clip having the following characteristics:— the spline-clip has a unitary cross-sectional profile that includes a wall-spline and a jamb-spline, the two splines protruding from a connecting web of the clip; andthe web has a wall-contact surface, and the spline-clip is so structured that the wall-contact surface of the web can make touching contact with the flat surface of the wall;providing the frame as a split-frame, comprising an inside-frame that includes left and right inside-jambs, and a separable outside frame that includes left and right outside-jambs, wherein:— the split-frame includes an engageable split-guide, which is so structured that, when the split-guide is engaged, the inside-frame is movable relative to the outside-frame, being guided and constrained by the split-guide for relative movement only towards and away from the outside-frame, being the inside-outside direction;the structure of the split-guide is such that the inside-frame can be assembled to the outside-frame, in the inside-outside direction, and when assembled thereto the split-guide is effective to prevent relative movement between the inside and outside frames in the left-right and up-down directions; andthe outside-frame lies assembled into the opening in the wall, and is rigidly fixed to the wall;attaching the inside set of spline-clips to the inside-frame, thereby forming an inside sub-assembly comprising the inside-frame and the inside spline-clips attached thereto;positioning the inside sub-assembly in the opening in the wall;engaging the split-guide, and moving the inside sub-assembly towards the outside sub-assembly until the respective wall-contact-surfaces of the inside spline-clips lie flat against the inside surface of the wall;then driving fasteners through the webs of the inside spline-clips, thereby fastening the inside spline-clips and the inside-frame to the wall; andthen assembling wood trim onto the inside spline-clips.

2. As in claim 1, including, prior to assembling the inside frame into the opening, assembling the outside-frame into the opening by the following procedure: providing an outside set of the plastic spline-clips;attaching the outside spline-clips to the outside-frame, to form an outside sub-assembly comprising the outside-frame and the outside spline-clips attached thereto;positioning the outside sub-assembly in the opening in the wall;with the wall-contact-surfaces of the outside spline-clips flat against the outside surface of the wall, adjusting the orientation of the outside-door-frame until the outside door-frame is aligned squarely within the opening;then driving fasteners through the webs of the outside spline-clips, thereby fastening the outside spline-clips and the outside-frame to the wall; andthen assembling wood trim onto the outside spline-clips.

3. As in claim 2, wherein: the outside-frame is a doorframe, and includes a door; andthe door is hinged to one of the left and right inside-jambs, and latched to the other.

4. As in claim 1, including: providing the wood trim with the following characteristics:— the wood trim has a unitary cross-sectional profile that includes a wall-spline-slot and a jamb-spline-slot;the respective proximal walls of the slots together define a male dovetail form, being of a maximum overall width DM;the profile includes a wall-land, beyond the wall-spline-slot, for making contact with an outer flat surface of the wall; andthe profile includes a jamb-land, beyond the jamb-spline-slot, for making contact with an edge face of a jamb component of the frame; andproviding the spline-clips with the following characteristics:— the two splines of the spline-clip are so angled relatively, and both so angled relative to the web, as to define a female dovetail shape between the two splines;the two splines converge together, the further away from the web, to a minimum distance apart DF, where DF is smaller than DM; andthe spline-clip is elastically deflectable, to the extent that the splines can be separated to the distance DM by the application of a separating force, and can recover resiliently, without damage, upon the separating force being no longer applied.

5. As in claim 1, wherein: the inside-jambs and the outside-jambs have respective edge-faces facing each other; andproviding the engageable split-guide by forming respective key-grooves formed in the respective edge-faces, and providing a key which engages both key-grooves.

6. As in claim 1, including attaching the inside set of spline-clips to the inside-frame by the following procedure: the inside-jambs having respective inside edge-faces lying in substantially the same plane as the inside surface of the wall, forming respective inside spline-clip grooves in the inside edge-faces of the inside jambs;providing respective barbed lugs on the webs of the inside spline-clips, the barbed lugs protruding towards the inside-jambs;engaging the barbed lugs into the spline-clip grooves;designing the lugs on the inside spline-clips to be a tight fit in the spline-clip grooves in the inside jambs, whereby, when the lug is present inside the spline-clip groove, the spline-clip is thereby secured firmly to the jamb.

7. As in claim 1, including: in the left-right sense, by so moving the sub-assembly that the web of the inside clip moves horizontally over the inside surface of the wall;in the up-down sense, in that the flat of the web of the inside clip is movable vertically over the flat inside surface of the wall, while remaining in contact with that surface;

8. Combination of wood-trim and spline-clips, wherein: the spline-clips are effective to attach the wood-trim around a door or window installation, being an installation that includes an opening in a wall;the wall, in respect of a cross-sectional profile of the opening in the wall, includes parallel opposite outer surfaces, and includes also a jamb-piece;the jamb-piece has respective outer surfaces which are at least approximately co-planar with the outer surfaces of the wall;the spline-clips of the combination are of plastic material, which is capable of being pierced by a pointed fastener such as a staple or nail;each spline-clip is configured as follows: —the spline-clip is in one piece, which has a profile having an overall width W;the width W of the spline-clip includes a web-portion, which is shaped to lie flat against one of the outer surfaces of the wall;the web-portion is shaped to bridge a gap between one of the outer surfaces of the wall and the co-planar outer surface of the jamb-piece;the web-portion of the spline-clip has a wall-end and a jamb-end;at or near the wall-end of the web, the spline-clip includes a protruding wall-spline;at or near the jamb-end of the web, the spline-clip includes an protruding jamb-spline;each spline has an inner-side-face, being, in respect of each spline, the face that faces the other spline;the respective inner-side-faces of the splines on the spline-clip lie spaced apart a distance DC;the inner-side-faces slope inwards with respect to the web-portion, in such manner that the respective inner-side-faces of the two splines of the spline-clip together create a female dovetail form;the distance DC is measured parallel to the wall, and the female dovetail form is so configured that the distance DC decreases in proportion to the spacing of the distance DC from the wall;the splines have tips, and the minimum value of the distance DC, termed DC-min, occurs at or near the tips;the wood-trim has the following characteristics:the wood-trim is made of rigid solid material;the wood-trim has a profile that includes a wall-side face, being a face of the trim that lies against the wall, and is thereby hidden from view, when installed;formed into the wall-side face of the trim are two spline-slots, being a wall-end spline-slot and a jamb-end spline-slot;the two spline-slots are angled inwards, at angles corresponding to the respective slopes of the two splines;the two spline-slots in the wood-trim have respective inner-faces, which lie spaced apart a distance DT;the two inner-faces slope inwards with respect to the web-portion, in such manner that the two inner-faces of the slots in the wood-trim together create a male dovetail form;the distance DT is measured parallel to the wall, and the male dovetail form is so configured that the distance DT decreases in proportion to the spacing of the distance DT from the wall;the slots have entry corners, and the maximum magnitude of the distance DT, termed DT-max, occurs at or near the entry-corners;the distance DC-min of the female dovetail form is smaller than the distance DT-max of the male dovetail form;the plastic material of the spline-clip is flexible and pliable enough that, when the splines are forced apart with a force F of such magnitude that the minimum distance DC-min between the splines is increased to the distance DT-max, and then released, the splines spring back resiliently without taking a permanent set; andthe solid material of the wood-trim is rigid enough that a force of the same magnitude as the force F, when applied between the entry-corners, causes substantially no reduction in the distance DT-min.

9. As in claim 8, wherein: the distance DT-max of the solid material of the trim is greater than the distance DT-min measured when the plastic material is unstressed, by an interference distance ID millimetres;ID is at least ½ mm.

10. Procedure for fixing a doorframe or windowframe, termed a frame, in an opening in a wall, and for applying wood trim around the frame, including: providing wood trim having the following characteristics: the wood trim has a unitary cross-sectional trim profile that includes a wall-spline-slot and a jamb-spline-slot;the respective proximal walls of the slots in the trim profile together define a male dovetail form, being of a maximum overall width DM;the trim profile includes a wall-land, beyond the wall-spline-slot, for making contact with a flat surface of the wall; andthe profile includes a jamb-land, beyond the jamb-spline-slot, for making contact with an edge face of a jamb component of the frame;providing an inside set of plastic spline-clips, each having the following characteristics:— the spline-clip has a unitary cross-sectional spline-clip profile that includes a wall-spline and a jamb-spline, the two splines protruding from a web of the spline-clip, which joins the two splines;the web has a wall-contact surface, and the spline-clip is so structured that the wall-contact surface of the web can make touching contact with the flat surface of the wall;the two splines are so angled relatively as to define a female dovetail shape between the two splines;the two splines converge together, the further away from the web, to a minimum distance apart DF, where DF is smaller than DM; andthe spline-clip is resiliently deflectable, to the extent that the splines can be separated to the distance DM by the application of a separating force, and can recover elastically, without damage, upon the separating force being no longer applied;making a sub-assembly of the frame and the inside set of plastic spline-clip;fixing the spline-clips to the frame, in the sub-assembly;placing the sub-assembly in the opening;adjusting the position of the sub-assembly in the inside-outside sense relative to the opening in the wall by moving the sub-assembly in the inside-outside direction until the flat of the web of the clip lies in contact with the flat inside surface of the wall;with the web of the spline-clip in contact with the flat wall surface, driving a fastener through the web and into the wall;with the spline-clip attached to the wall, and the two splines of the spline-clip protruding out from the wall, assembling the wood trim onto the spline-clip by placing one of the grooves in the wood trim over one of the splines of the spline-clip;so positioning the wood trim, and so applying a manual force to the wood trim in the direction towards the wall, that the male dovetail in the wood trim, in moving towards the wall, bends one of the splines outwards relative to the other spline, with such deflection as to enable the male dovetail to enter between the splines;pressing the wood trim so far towards the wall that the elasticity of the spline-clip causes the spline to move back, over the male dovetail;whereby the splines apply a force to the male dovetail urging the wood trim in the direction towards the wall.

11. Corner cover apparatus, for covering corners at which two pieces of profiled trim converge, in combination with the trim, wherein: the trim is of the same cross-sectional trim profile at all points along its length;the trim has an outside or front face, which is formed with a front face profile;the two pieces of trim converge at an angle A;the corner-cover includes two limbs, set at the angle A to each other;the two limbs are joined rigidly together at the apex of the angle A;the limbs have respective inside faces, having respective inside face profiles;in respect of each limb of the corner-cover:— the inside face profile of the limb is the same at all points along the length of the limb;the front face profile of the limb is the same at all points along the length of the limb;the limb is shaped and dimensioned to fit against the trim; andwhen so fitted, the inside face profile of the limb lies against the front face profile of the trim and the front face profile of the limb is visible; andthe apparatus includes a fastening means, which is effective to urge the inside faces of the limbs into contact with the respective front faces of the two converging pieces of trim, and thus to attach the cover to both pieces.

12. As in claim 11, wherein the profile of the trim is so configured that, when the pieces of trim are fitted to converging walls, with the lengths of the pieces disposed horizontally along the walls, the height or vertical dimension of the profile is much greater than the thickness or horizontal dimension of the profile.

13. As in claim 11, wherein the two limbs of the corner-cover are formed together as a unitary structure.

14. As in claim 11, wherein: in respect of the two limbs, the cross-sectional thickness of the limb, being the smallest distance between the inside face profile and the front face profile of the limb, is the same at all points along the length of the limb; andthe cross-sectional thickness of the limb, being the smallest distance between the inside face profile and the front face profile of the limb, is at least approximately the same over the whole extent of the face profiles.

15. As in claim 11, wherein the inside face profile of the limb is formed as an accurate negative of the front face profile of the trim, in that, when the limb of the corner-cover is placed against the front face of the limb, the inside face profile of the corner-cover conforms closely to the front face profile of the limb.

16. As in claim 11, wherein, in respect of the two limbs, the front face profile of the limb conforms at least approximately to the inside face profile of the limb, to the extent that the visible appearance of the corner-cover, when viewed with the trim, merges unobtrusively with the visible appearance of the trim.

17. As in claim 11, wherein the corner-cover apparatus includes an outer cover of relatively hard rigid material on which the front face profile is formed, and a lining of relatively soft, flexible, deformable material, such as a foam or sponge material, on which the inside-face profile is formed.

18. As in claim 11, wherein: the fastening means comprises patches of adhesive present on the inside faces of the limbs of the corner-cover; andthe adhesive is protected with respective protectors which can be peeled away just before applying the corner-cover to the pieces of trim.

19. As in claim 11, wherein the trim is one of baseboard trim or chair rail trim.

20. As in claim 11, wherein the angle A is a right angle, and the lengths of the limbs are between three and ten cm.

21. As in claim 11, wherein a pair of the corner-covers are configured one to cover an external corner and the other to cover an internal corner.

22. As in claim 11, wherein: the corner-cover includes a platform, which is configured to overlie an upwards-facing top surface of the trim; andthe platform is of a thickness that is thinner than that of the cross-sectional profile of the limb, between the front profile and the inside profile.

23. As in claim 11, wherein the material of the corner-cover is one of solid wood, or injection-moulded plastic.

24. System for attaching trim, including baseboard trim and chair-rail trim, to a wall of a room, wherein: the system includes hook-clips, and includes fasteners whereby the hook-clips can be attached to the wall;the trim is of the same cross-sectional trim profile at all points along its length;the hook-clips are of the same cross-sectional hook-clip profile along their lengths;the trim profile includes a hook-engaging surface, which faces into the room;the trim profile includes a wall-facing-surface;the hook-clip profile includes an upstanding hook, having a hook surface, which faces the wall;the hook-clip profile includes a buffer, having a buffer surface, which faces into the room;at least one of the hook or the buffer is resiliently or elastically deflectable;the system is so configured that, when the hook-clips are attached to the wall, the trim can be attached to the hook-clips by lowering the trim downwards onto the hook-clips, and can be removed from the hook-clips by lifting the trim upwards from the hook-clips;the trim profile is so configured, in relation to the wall and to the hook-clip profile, that when the trim is lowered down onto the hook-clips, the trim profile touches the hook profile at (i) a top-of-trim contact point T, at (ii) a hook contact point H, and at (iii) a buffer contact point B, wherein:— the point T is a point on the wall-facing surface of the trim, at or near the top of the trim profile, and on the wall, at which forceful contact occurs;the point H is a point on the wall-facing hook-face of the hook, and on the room-facing hook-engaging surface of the trim, at which forceful contact occurs; andthe point B is a point on the wall-facing back surface of the trim, and on the room-facing buffer surface of the buffer, at which forceful contact occurs;the point T lies above the point H, and the point B lies below the point H; andthe effect of the forceful contacts is such that the said at least one of the hook or the buffer undergoes an elastic deflection.

25. As in claim 24, wherein: the hook-clip profile includes a ledge;the trim profile includes a nose; andthe nose and the ledge are so located in their respective profiles that the trim can be lowered down onto the hook-clips until the nose comes to rest on the ledge.

26. As in claim 24, wherein: the profile of the trim includes a hook-slot, one side of which comprises the room-facing hook-engaging surface of the trim profile, and the other side comprises a hook-slot wall-facing surface of the trim profile;the sides of the hook-slot in the trim profile are substantially parallel;the hook is slightly thicker than the width apart of the sides of the hook-slot, to the extent that the hook interferes with the hook-slot;the surface of the hook is rippled, thereby limiting the interference grip of the hook in the hook-slot;whereby the interference provides a controlled retention force, which resists removal of the trim from the hook-clips.

27. As in claim 24, wherein: the profile of the trim is so shaped, as a whole profile, that it can be cut in a profile cutting machine;being a machine in which the trim passes through along a work-line, and the profile is cut by saws or cutters which rotate about respective axes; andeach axis forms a right angle to the work-line when viewed from above and from the side of the work-line.

28. As in claim 24, wherein: the profile of the trim and the profile of the hook-clip are so configured that, when the trim is assembled to the hook-clips, the trim is capable of rotating or rocking about the hook as a fulcrum;whereby, during installation, when the trim is touching the hook at the point H, and is touching the buffer at the point B, the said elastic deflection urges the trim profile to rotate, about the hook, in the sense to move the top of the trim towards the wall;thereby creating the said forceful contact between the top of the trim and the wall at the point T.

29. As in claim 24, wherein: all the said surfaces are vertical or have a substantial vertical component; whereby:— forces created by the forceful contact at the points T, H, and B are all horizontal or have a substantial horizontal component; andthe horizontal contact force at the point H is reacted by the sum of the horizontal forces at the points T and B.

30. As in claim 24, wherein each hook-clip is of a unitary structure, the hook and the buffer being formed together in the profile thereof.

31. As in claim 24, wherein: the trim profile is relieved at locations between the contact-points, to the extent that contact with the wall of the room occurs only at point T, and contact with the buffer occurs only at point B;the point T is at the very top of the trim profile, in that substantially no portion of the trim profile protrudes above the point T; andthe point T lies at the junction between an upwards-facing top surface of, and a wall-facing back surface of, the profile of the trim.

32. Procedure for attaching an inside jamb-frame and trim to an outside jamb-frame of an existing doorframe or window frame, by the following procedure: providing a profiled moulding, the profile of which is formed with an internal angle;where the internal angle is dimensioned to fit over and engage with a corner of an the edge face of the existing outside-jamb;fixing the profiled moulding to the existing outside-jamb;where the profile of the profiled moulding includes a slot, and where a key engages the slot, and thereby locates or positions the inside jamb-frame with respect to the profiled moulding, and thereby with respect to the outside jamb-frame;attaching an inside set of spline-clips to an edge face of the outside frame;positioning the inside frame, with the inside spline-clips attached, such that the inside spline-clips lie flat against the inside wall;driving fasteners through the webs of the inside spline-clips, to secure the inside spline-clips, andthereby the inside jamb-frame, to the wall;then applying wood trim to the inside spline-clips.

33. As in claim 32 wherein the key is separable from the inside jamb-frame.