GB2621972A

GB2621972A - Edge-protecting device for a door leaf

Info

Publication number: GB2621972A
Application number: GB2210070.5A
Authority: GB
Inventors: Watts Allan; Russel Robert
Original assignee: RAM EXTRUSION Ltd
Current assignee: RAM EXTRUSION Ltd
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2024-03-06
Also published as: GB202210070D0

Abstract

A door edge-protecting device 1 comprising an elongate body 3 with a channel having two sides 9A 9B suitable for gripping the front and rear faces of the door panel 103 and an intumescent layer 15 covering the whole of the base of the channel. The channel is preferably U shaped and the two side arms 9A 9B are preferably resiliently deflectable and form a channel where the opening is narrower than the base. A method of manufacture is also defined. A spacer 17 may be located between the intumescent layer and the edge of the door and manufactured from a mixture of plastics material and intumescent material. A smoke seal 19 may be provided on the external face of the channel. In use the edge protecting device is fitted over the edge of the door, when exposed to heat in a fire the intumescent material expands pushing the base of the channel outwards and into contact with the door frame thus creating a continuous seal between the base and the frame.

Description

TITLE

Edge-protecting device for a door leaf.

TECHNOLOGICAL FIELD

Examples given in the present disclosure relate to an edge-protecting device for a door leaf. Some examples relate to an edge-protecting device contributing to passive fire prevention and thus suitable for use with a fire door.

BACKGROUND

Edges of door leaves can be damaged in the course of normal functioning (opening and closing) whether by normal wear or by impact with/upon objects. Fitting edge-protecting devices can reduce the damage to door leaves.

Attaching intumescent strips to the inside of a door frame or to the frame-opposing faces of a door leaf provides a form of passive fire protection. Upon exposure to heat from a fire, these intumescent strips swell to seal the gap between the door frame and door leaf.

BRIEF SUMMARY

According to various, but not necessarily all examples of the disclosure there is provided an edge-protecting device for a door leaf, comprising an elongate body and an intumescent layer. The elongate body comprises a channel which is substantially coextensive with the elongate body. The channel has a base extending between a pair of sides which are configured to grip front and rear faces of a door leaf received within the channel. The intumescent layer is fixed within the channel and arranged to cover a whole of the base of the channel.

The intumescent layer may comprise at least 40% intumescent material by weight.

The intumescent layer may have a thickness of 1.5 mm.

The edge-protecting device may comprise a further, spacer layer fixed within the channel comprising a mixture of plastics material and intumescent material.

A gap may be provided between the intumescent layer and the sides of the channel, at least when the sides are undeflected.

The channel may not comprise grooves or recesses in its inner surface.

The sides may be resiliently deflectable.

The channel opening may be narrower than the base.

The elongate body may have a generally U-shaped cross-section.

The edge-protecting device may comprise a smoke seal formed as a projection on an opposite side of the elongate body to the channel.

Outer corners of the elongate body may be formed of elastomeric material.

According to various, but not necessarily all examples of the disclosure there is provided a method of making an edge-protecting device for a door leaf The method comprises forming an elongate body with a channel which is substantially coextensive with the elongate body, the channel having a base extending between a pair of sides which are configured to grip front and rear faces of a door leaf received within the channel. The method further comprises arranging an intumescent layer to cover a whole of the base of the channel and fixing it within the channel.

The intumescent layer may be fixed within the channel by adhesion of intumescent layer to the base of the channel.

The elongate body may be formed by extruding a plastics material.

The method may comprise coextruding elastomeric material with the plastics material to form outer corners of the elongate body.

The extruded cross-section may comprise a projection on an opposite side of the elongate body to the channel which forms a smoke seal.

According to various, but not necessarily all examples of the disclosure there is provided a door leaf comprising a parallel front and rear faces bounded by edge faces which extend therebetween, wherein at least one of the edge faces is fitted with the edge-protecting device described in the foregoing portion of the 'Brief Summary' section, including as obtained by the described method.

According to various, but not necessarily all examples of the disclosure there is provided a door comprising a door frame to which at least one door leaf, fitted with the edge-protecting device, is attached.

According to various, but not necessarily all, examples there is provided examples as claimed in the appended claims.

While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. It is to be understood that various examples of the disclosure can comprise any or all of the features described in respect of other examples of the disclosure, and vice versa.

BRIEF DESCRIPTION

Some examples will now be described with reference to the accompanying drawings in which: FIGS 1 and 2 show an example of an edge-protecting device for a door leaf; FIG 3 shows an example of a door comprising a door leaf fitted with an edge-protecting device; and FIG 4 shows an example of a method of making an edge-protecting device.

The figures are not necessarily to scale. Certain features and views of the figures can be shown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggerated relative to other elements to aid explication. Similar reference numerals are used in the figures to designate similar features. For clarity, all reference numerals are not necessarily displayed in all figures.

DETAILED DESCRIPTION

FIGS 1 and 2 depict an example of an edge-protecting device 1 for a door leaf 103. FIG 2 depicts a cross-sectional view of the edge-protecting device 1 when fitted to an example door leaf 103. FIG 1 depicts a cross-sectional view of the edge-protecting device 1 when not fitted to the door leaf 103.

Example door leaves have parallel front and rear faces 105, 107 and edge faces 109 which bound both the front and rear faces 105, 107 and extend between them. Usually, the edge faces 109 are perpendicular to the front and rear faces 105, 107. The edge faces 109 are often provided by lipping.

The edge-protecting device 1 comprises an elongate body 3. The elongate body 3 may be of substantially the same length as the edge face 109 (and adjacent marginal regions of the front and rear faces 105, 107) that it is intended to protect.

The elongate body 3 comprises a channel 5 which is substantially coextensive with the elongate body 3. The channel 5 extends over substantially the same length as the elongate body 3. The channel 5 may be the same length as the elongate body 3, therefore running the full length of the elongate body 3 (coextensive with the elongate body 3) and opening out at either end of the elongate body 3. Alternatively, the channel may be shorter than the elongate body 3 such that the channel 5 is closed at one or both ends. The length of the elongate body 3 will be such that it fits within the door frame 111 (see FIG 3) whilst fitted to the door leaf 103 attached to the door frame 111 such that the door leaf 103 is received within the channel 5. A minimum length of the channel 5 is set by the height (or width) of the door leaf 103, while a maximum length of the elongate body 3 is set by the height (or width) under the door frame 111. In some examples the extension of the elongate body 3 beyond either end of the channel 5 may function to fit within and reduce the gap between the door leaf 103 and the door frame 111 to which it is attached. This may, for example, assist in smoke sealing.

The channel 5 is open along its length on one side (opening 13) so as to be able to receive a door leaf 103 within the channel 5. The channel 5 has a base 7 extending along the channel's length in one dimension and between a pair of sides 9A, 9B in another dimension.

The base 7 of the channel 5 may be flat or slightly concave, but in either case may be smooth in the sense of comprising no engineered protrusions and/or indentations (rather than smooth in the sense of surface texture). For example, the base 7 may comprise no grooves or recesses. There may however be holes through the elongate body 3 which have openings in the base 7 and through which screws may be received for the purpose of securing the edge-protecting device 1 to the edge face 109 of the door leaf 103 received in the channel 5. In some examples, the channel 5 may comprise no grooves or recesses in its inner surface, be that the base 7 or the pair of sides 9A, 9B.

The base 7 has a width commensurate with the edge face 109 of the door leaf 103 to which the edge-protecting device 1 is intended to be fit. For example, fire doors offering at least 30 minutes of protection against fires (FD30) or at least 60 minutes of protection against fires (FD60) will typically have a thickness of 44 mm or 54 mm respectively. The base 7 may therefore have a width of 44 mm or 54 mm depending on which of the doors the edge-protecting device 1 is intended to be fit. The width of the base 7 may be constant along the length of the channel 5.

The pair of sides 9A, 9B are configured to grip front and rear faces 105, 107 of the door leaf 103 received within the channel 5. The pair of sides 9A, 9B may be configured to grip marginal regions of the front and rear faces 105, 107, which marginal regions are adjacent the edge face 109 of the door leaf 103 which is received within the channel 5.

In some examples, the sides 9A, 98 are resiliently deflectable. When not deflected, the sides 9A, 9B may be closer together at the opening 13 of the channel 5 than at its base 7. The opening 13 of the channel 5 is therefore narrower than its base 7. Accordingly, when a door leaf 103 with an edge face 109 of a width commensurate with the base 7 is received within the channel 5, the sides 9A, 93 are deflected outwards (as shown in FIG 2) and, due to their resilience, exert an inwardly-directed returning force, thus increasing the grip on the front and rear faces 105, 107 of the door leaf 103 within the channel 5.

The sides 9A, 9B may form curved (concave) junctions 11A, 11B with the base 7. The curved junctions 11A, 113 do not concentrate stress to the same extent as a sharp corner would. Therefore, the deflection of the sides 9A, 9B is less likely to damage the elongate body 3.

The depth of the channel 5 (the distance between the opening 13 and the base 5) may be 6 mm or more, preferably between 6 mm and 50 mm, more preferably approximately 18.5 mm.

As depicted in FIGS 1 and 2, a shape of the channel 5 may be defined by the geometry of the elongate body 3 which, in some examples, has a generally U-shaped cross-section. The parts of the body 3 providing the sides 9A, 93 may be inclined towards one another and/or bend inwards at the opening 13 of the channel 5. The portion of the sides 9A, 9B bending inwards may make an obtuse angle with the rest of the sides 9A, 93, in particular an obtuse angle greater than 135 arc degrees. In either case, the opening 13 of the channel 5 is, as a result, made narrower than its base 7.

In other examples, the elongate body 3 has a generally C-shaped cross-section which provides portions of the sides 9A, 93 that bend inwards at the opening 13 of the channel 5 to make an angle with the rest of the sides 9A, 93 which is less than 135 arc degrees.

The bending inwards at the opening 13 of the channel 5 enables the sides 9A, 9B to grip the front and rear faces 105, 107 of the door leaf 103 in the event that the edge-protecting device 1 is fitted over an edge face 109 which is slightly wider than the width of the channel 5 and which thus causes the sides 9A, 9B to splay outwards. The bend inwards at the opening 13 of the channel 5 closes the gap which would otherwise result between the channel opening 13 and the front and rear faces 105, 107. The bending inwards at the opening 13 of the channel 5 also reduces the potential for snagging on the edge-protecting device 1.

In the foregoing examples where the geometry of the elongate body 3 defines the geometry of the channel 5, the thickness of the elongate body 3 is substantially uniform and may range between 0.7 mm and 2.5 mm. The modal thickness may be approximately 1 mm. The part of the body 3 providing the base 7 of the channel 5 may be 1 mm thick. The parts of the body 3 providing the sides 9A, 98 may be thicker where the sides 9A, 98 form the curved junctions 11A, 11B with the base 7 and/or thinner at or close to the channel opening 13. The thinness of the body 3 may make the sides 9A, 9B more easily deflectable.

The elongate body 3 is preferably formed from a material having suitable impact resistance for protecting the edge face 109 and adjacent marginal regions of the front and rear faces 105, 107 of the door leaf 103. The elongate body 3 may for example be formed from a plastics material such as PVC which is advantageously, from a manufacturing perspective, extrudable. Other extrudable materials, whether plastic or not, having the suitable impact resistance may alternatively be used to form the elongate body 3.

The edge-protecting device 1 comprises an intumescent layer 15 fixed within the channel 5 and arranged to cover a whole of the base 7 of the channel 5.

Accordingly, the intumescent layer 15 is interposed between the elongate body 3 (the base 7 of the channel 5 in particular) and the edge face 109 of the door leaf 103 received within the channel 5.

By fixing the intumescent layer 15 within the channel 5, its expansion has the effect of pressing the elongate body 3 firmly against the door frame 111. This provides fire-stopping both by closing the gap between the door leaf 103 and door frame 111 which would otherwise permit fire penetration and by resisting deformation of the door leaf 103 upon exposure to fire (such as the sides, especially the side furthest from the hinge(s), bowing towards the fire) which would otherwise open a fire-penetrable gap. The edge-protecting device 1 is thereby adapted into a fire seal.

By arranging the intumescent layer 15 to cover the whole of the base 7 of the channel 5, as it expands upon exposure to heat, the pressure applied between the edge face 109 of the door leaf 103 and the door frame 111 is evenly distributed via the edge-protecting device 1 which therefore creates a stable fire seal and avoids distortion of the elongate body 3 which, as per some of the foregoing examples, may be thin and thus otherwise potentially susceptible to deformation. Returning briefly to discussion of the elongate body 3, the thinness (for example, the part of the body 3 providing the base 7 of the channel 5 being 1 mm thick) advantageously enables rapid transfer of heat to the intumescent layer 15 within the channel so that the edge-protecting device 1 provides a fast-acting fire seal.

The intumescent layer 15 exhibits net intumescent properties such as net expansion upon exposure to heat. It comprises intumescent materials, which is to say: materials having intumescent properties. Examples of intumescent materials which may be comprised in the intumescent layer 15 include graphite, sodium silicate, or any other intumescent material providing a suitable expansion rate such as, for example, 3 to 4 times by volume in 10 minutes at 180 °C.

In some examples the intumescent layer 15 comprises at least 40% intumescent material by weight. The precise quantity of intumescent material can be chosen such that net expansion of the intumescent layer 15, in a fire test specified in British Standard B5476 Part 22: 1987, is at least 200% (i.e., expands to at least three times its original volume). The intumescent layer 15 can consist entirely of intumescent material. Where the intumescent layer 15 comprises other, non-intumescent materials, these may include suitable plasticisers, fillers and stabilisers.

The intumescent layer 15 may be an elongate strip having a constant width, for example equal to that of the base 7 which it covers, and having a length equal to that of the channel 5.

The intumescent layer 15 may be one or more orders of magnitude wider than it is thick. The intumescent layer 15 may be at least ten times wider than it is thick. The intumescent layer 15 may be one or more orders of magnitude longer than it is wide.

The intumescent layer 15 may be at least ten times longer than it is wide.

The thickness of the intumescent layer 15 may be substantially constant. This should be understood in the context of the intumescent layer having a substantially rectangular cross-section, though to the extent that the base 7 may be slightly concave, the base-facing surface of the intumescent layer 15 may be correspondingly convex to enable face-to-face contact across the whole of the base 7.

In some examples the intumescent layer 15 has a thickness of 1 mm or more. An intumescent layer with a thickness of less than 1 mm is harder to produce and less suitable for certain production processes like extrusion because crystals of graphite, sodium silicate, or other crystalline intumescent materials are more likely to become lodged in the die. It can be preferable to keep the intumescent layer 15 thin so that the edge-protecting device 1 can be fit to door leaves 103 having already a small gap between the edge face 109 and the door frame 111. In some examples, it may be preferable for the intumescent layer to have a thickness of less than 4 mm. More preferably, the intumescent layer 15 has a thickness of approximately 1.5 mm.

In some examples the intumescent layer 15 is fixed to the base 7 but not fixed to the sides 9A, 9B. For example, the intumescent layer 15 may be secured over the whole base 7 by an adhesive, but not secured against the sides 9A, 9B. The intumescent layer 15 may not be adhered to the sides 9A, 9B. Accordingly, outward deflection of the sides 9A, 9B does not directly impart tensile stress to the intumescent layer 15. It will be appreciated that other means of fixing or securing the intumescent layer 15 to the base 7 can be used. For example, the intumescent layer 15 could be coextruded with the elongate body 3 and thus be secured to the body 3 by fusion.

In some examples, there is provided a gap between the intumescent layer 15 and the sides 9A, 9B such that the intumescent layer 15 is not in contact with the sides 9A, 9B, at least when the sides are not deflected inwards. For example, the intumescent layer 15 may be arranged to cover the whole of the base 7 but not the junctions 11A, 11B with the sides 9A, 9B. The gap provides space for the intumescent layer 15 to expand into when exposed to heat rather than said expansion causing outward deflection of the sides 9A, 9B which could loosen the grip on door leaf 103.

In other examples the intumescent layer 15 may be applied as a coating over the entire inner surface of the channel 5.

In any of the foregoing examples, the edge-protecting device 1 can optionally comprise a further, spacer layer 17 fixed within the channel 5. The function of the spacer layer 17 is to create and maintain a desired amount of space between the intumescent layer 15 and the edge face 109 of the door leaf 103 so as to control a gap between the elongate body 3 and the door frame 111 to which the door leaf 103 is attached.

The spacer layer 17 comprises a lower percentage of intumescent material by weight than the intumescent layer 15. The spacer layer 17 comprises a mixture of plastics material and intumescent material. The purpose of using intumescent material in the spacer layer 17 is to compensate for the shrinkage, deformation or the like of the plastics material under heat exposure to thereby maintain the desired amount of space between the intumescent layer 15 and the edge face 109 of the door leaf 103. The quantity of intumescent material present is therefore selected, relative to the likely expansion thereof in the event of a fire, such that the overall dimensions of the spacer layer 17 do not significantly alter.

One form of intumescent material that is particularly convenient to use for the spacer layer 17 is graphite as this material is of relatively low cost compared to other intumescent materials and can readily be mixed with a plastics material. The resulting formulation is also suitable for use in an extrusion process. However, the invention is not restricted in this regard and other production processes may be used and other materials may be used.

The plastics material can be a PVC material or other extrudable material, and may include suitable plasticisers, fillers and stabilisers. The intumescent material preferably makes up less than 50% by weight of the material of the spacer layer 17. More preferably, it may make up less than 25% by weight. Where graphite is used as the intumescent material, intumescent material may make up a value selected from the range approximately 10% to approximately 20% by weight of the material of the spacer layer 17.

It has been found that a spacer layer 17 using a quantity of graphite intumescent material in the regions of 10-20% by weight, results in spacer layer 17 that, in use, does not undergo a significant change of dimensions in the event of a fire, the expansion of the intumescent material within the material of the spacer layer 17 compensating for any shrinkage or movement of other materials in the spacer layer 17.

The precise quantity of intumescent material in the mix can be chosen such that net expansion of the spacer layer 17, in a fire test specified in British Standard B5476 Part 22: 1987, is less than 2% over at least 30 minutes. The minimal expansion is because the expansion of the intumescent material compensates for the shrinkage, deformation or the like of the plastics material.

As mentioned above, the material composition of the spacer layer 17 may include a filler, for example in the form of chalk. This may make up, for example, 30-50% by weight of the material, and preferably makes up around 40% by weight thereof It may also contain a plasticiser making up, for example, 10-20% by weight of the material, conveniently forming approximately 16% by weight thereof. The material may also include a stabiliser making up approximately 5% by weight, and acrylic making up approximately 1% by weight of the material. The remainder is of a suitable plastics material such as PVC, the PVC making up, for example, 25-40% by weight of the material, preferably making up approximately 32% by weight thereof.

The spacer layer 15 may have substantially the same width as the intumescent layer 15. It may continuously extend the full length of the channel 5. In some examples the spacer layer 15 may be loosely arranged within the channel 5 while in other examples it may be secured to the intumescent layer 15, for example by adhesion. The thickness of the spacer layer 17 is chosen to control gap condition between the door leaf 103 (or edge-protecting device 1 fitted thereto) and the door frame 111.

Because the edge-protecting device 1 described in any of the foregoing examples can be made thin (for example, the part of the body 3 providing the base 7 of the channel 5 may be 1 mm thick and the intumescent layer 15 which overlies the base 7 may be 1.5 mm thick), it will only very infrequently be necessary to take the lipping off a door leaf 103 which is to be adapted into a fire door (for which it is conventional to maintain a gap of between 2 mm and 4 mm between the door leaf 103 and the door frame 111) or to shave down the edge face 109 onto which the edge-protecting device 1 is to be fit. There is accordingly little constraint on the extent to which the gap condition between the door leaf 103 (or edge-protecting device 1 fitted thereto) and the door frame 111 can be controlled by the choice of thickness for the spacer layer 17.

In any of the foregoing examples, the edge-protecting device 1 can optionally comprise a smoke seal 19 formed as a projection on an opposite side of the elongate body 3 to the channel 5.

The smoke seal 19 provides a resiliently deformable seal against the inner surface of the door frame 111. It may be formed of Nitrile PVC or other suitable materials.

The smoke seal 19 may be the same length as the elongate body 3, thus providing a seal against the inner surface of the door frame 111 along a full edge of the door leaf 103.

The smoke seal 19 can be integrally formed with the elongate body 3, for example, being secured thereto by fusion between the material of the elongate body 3 and the material of the smoke seal 19.

The smoke seal 19 may be provided as a 6 mm projection which can be trimmed to an appropriate size to fit the door 101 in question.

In some examples, the smoke seal 19 is offset from the centre of the elongate body 3. Edge-protecting devices 1 comprising the smoke seal 19 can therefore be used in a double-leaf door without the smoke seals 19 extending from either door leaf interfering with each other, as they would if they were positioned in the centre. This requires the edge-protecting devices 1 to be installed on each door leaf with the smoke seals 19 offset to different sides of the centre. The extent of the offset is such that the smoke seals 19 do not contact each other as one door leaf swings past the other.

In any of the foregoing examples, the outer (exterior) corners 21A, 21B of the elongate body 3 can optionally be formed of elastomeric material. These dampen the forces transmitted upon impact with objects.

In some examples, the outer corners 21A, 21B are rounded (convex) The outer corners 21A, 21B can be integrally formed with the elongate body 3, for example, being secured thereto by fusion between the material of the elongate body 3 and the elastomeric material from which the outer corners 21A, 21B are formed.

FIG 3 depicts a door 101 to which an edge-protecting device 1, as per any of the foregoing examples, has been fit. The door 101 can be a fire door offering at least 30 minutes of protection against fires (FD30) or at least 60 minutes of protection against fires (FD60). Such doors 101 typically have door leaves 103 having thicknesses of 44 mm or 54 mm respectively.

The door 101 comprising a door frame 111 to which at least one door leaf 103 is attached. The door leaf 103 comprises parallel front and rear faces 105, 107 bounded by edge faces 109 which extend therebetween (as described hereinbefore). The door leaf 103 is attached at one edge face 109B (the hinge face 109B) to the door frame 111 by one or more hinges 113.

At least one of the edge faces 109 is fitted with the edge-protecting device 1. In some examples at least the edge face 109A which is opposite the hinge face 109B (the swinging face 109A) is fitted with the edge-protecting device 1. An aperture may be cut though, or otherwise formed in, the edge-protecting device 1 for functioning of the latch. Appropriately sized edge-protecting devices 1 may also be fitted to the top and bottom edge faces 1090, 109D. An intumescent strip, equivalent to the intumescent layer 15, can be applied to the hinge face 109B or an edge-protecting device 1 can be fitted to the hinge face 109B with appropriately sized and positioned apertures for the one or more hinges 113.

It is to be appreciated that the door 101, while depicted as a single-leaf door in FIG 3, could be a double-leaf door, with each door leaf 103 being fitted with one or more edge-protecting devices 1.

In some examples a gap between the door frame 111 and the edge-protecting device 1, excluding any smoke seal 19 which it may comprise and which would be intended to make contact with the frame 111, is between 2 mm and 4 mm wide when the door 101 is in a closed configuration. A spacer layer 17 may be used to control this gap condition.

Fitting the edge-protecting device 1 to an edge face 109 comprises pressing this edge face 109 into the channel 5 defined by the edge-protecting device 1. The edge-protecting device 1 may be secured to the door leaf 103 by a gripping force exerted by the channel sides 9A, 9B on the marginal regions of the front and rear faces 105, 107 of the door leaf 103 and/or by fastening means between the edge face 109 and the base 7 of the channel 5. Such fastening means can include screws which can pass through the elongate body 3 and the intumescent layer 15 and into the door leaf 103. One screw may be located at one end of the channel 5 and another may be located at the other end of the channel 5 so that the edge-protecting device 1 is fastened to the edge face 109 of the door leaf 103 at either end of the edge face 109. Such fastening means can additionally or alternatively include adhesive such as self-adhesive (double-sided) tape, one layer of which can secure the intumescent layer 15 to the base 7 and another layer of which can secure the intumescent layer 15 to the edge face 109. In examples which include a spacer layer 17, rather than a layer of self-adhesive tape securing the intumescent layer 15 directly to the edge face 109, one layer of self-adhesive tape can secure the intumescent layer 15 to the spacer layer 17 and another layer of self-adhesive tape can secure the spacer layer 17 to the edge face 109.

FIG 4 illustrates a method 200 of making an edge-protecting device 1 for a door leaf 103 The method 200 comprising, at block 202, forming an elongate body 3 with a channel 5.

As in the foregoing, the channel 5 is substantially coextensive with the elongate body 3 and has a base 7 extending between a pair of sides which are configured to grip front and rear faces of a door leaf 103 received within the channel 5.

In some examples, the process used to form the elongate body 3 is extrusion. The elongate body 3 may be formed by extruding a plastics material, such as PVC. Alternative processes by which the elongate body 3 may be formed include, without limitation, drawing and moulding of a plastics material.

Optionally the method 200 may comprise coextruding elastomeric material with the plastics material to form the outer corners 21A, 213 of the elongate body 3 from the elastomeric material. The outer corners 21A, 21B are therefore secured to the elongate body 3 by fusion.

Optionally the extruded cross-section may comprise a projection on an opposite side of the elongate body 3 to the channel 5 which forms the smoke seal 19. The smoke seal 19 is therefore secured to the elongate body 3 by fusion.

At block 204 of the method 200, an intumescent layer 15 is arranged to cover a whole of the base 7 of the channel 5 and is fixed within the channel 5.

In some examples the intumescent layer 15 is fixed within the channel 5 by adhesion of intumescent layer 15 to the base 7 of the channel 5 The intumescent layer 15 can have a fixed cross-section and so, in some examples, the intumescent layer 15 may be formed by extrusion. The intumescent layer 15 may be formed by a separate extrusion process to the elongate body 3, and thereafter fixed within the channel 5. Alternatively, the intumescent layer 15 may be coextruded with the body 3 and therefore be secured thereto by fusion.

In view of the foregoing, it will be appreciated that in some examples the method 200 is a method comprising: extruding an elongate body 3 with a coextensive channel 5 which has a base 7 extending between a pair of sides which are configured to grip front and rear faces of a door leaf 103 received within the channel 5; and arranging an intumescent layer 15 to cover a whole of the base 7 of the channel 5 and adhering it thereto.

Where a structural feature has been described, it may be replaced by means for performing one or more of the functions of the structural feature whether that function or those functions are explicitly or implicitly described.

The term 'comprise' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use 'comprise' with an exclusive meaning then it will be made clear in the context by referring to "comprising only one..." or by using "consisting".

In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term 'example' or 'for example' or 'can' or may' in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus 'example', 'for example', can' or may' refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example.

Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

Features described in the preceding description may be used in combinations other than the combinations explicitly described above.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not.

The term a', 'an' or the' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a/an/the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use 'a', an' or the' with an exclusive meaning then it will be made clear in the context. In some circumstances the use of 'at least one' or 'one or more' may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result.

In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described.

The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure.

Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the Applicant may seek protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not emphasis has been placed thereon.

I/we claim:

Claims

CLAIMS1. An edge-protecting device for a door leaf, comprising: an elongate body comprising a channel which is substantially coextensive with the elongate body, the channel having a base extending between a pair of sides which are configured to grip front and rear faces of a door leaf received within the channel; and an intumescent layer fixed within the channel and arranged to cover a whole of the base of the channel.
2. The edge-protecting device of claim 1 wherein the intumescent layer comprises at least 40% intumescent material by weight.
3. The edge-protecting device of any preceding claim wherein the intumescent layer has a thickness of 1.5 mm.
4. The edge-protecting device of any preceding claim comprising a further, spacer layer fixed within the channel comprising a mixture of plastics material and intumescent material.
5. The edge-protecting device of any preceding claim wherein a gap is provided between the intumescent layer and the sides of the channel, at least when the sides are undeflected.
6. The edge-protecting device of any preceding claim wherein the channel comprises no grooves or recesses in its inner surface.
7. The edge-protecting device of any preceding claim wherein the sides are resiliently deflectable.
8. The edge-protecting device of any preceding claim wherein the channel opening is narrower than the base.
9. The edge-protecting device of any preceding claim wherein the elongate body has a generally U-shaped cross-section.
10. The edge-protecting device of any preceding claim wherein the edge-protecting device comprises a smoke seal formed as a projection on an opposite side of the elongate body to the channel.
11. The edge-protecting device of any preceding claim wherein outer corners of the elongate body are formed of elastomeric material. 10
12. A method of making an edge-protecting device for a door leaf, the method comprising: forming an elongate body with a channel which is substantially coextensive with the elongate body, the channel having a base extending between a pair of sides which are configured to grip front and rear faces of a door leaf received within the channel; and arranging an intumescent layer to cover a whole of the base of the channel and fixing it within the channel.
13. The method of claim 12 wherein the intumescent layer is fixed within the channel by adhesion of intumescent layer to the base of the channel.
14. The method of claim 12 or 13 wherein the elongate body is formed by extruding a plastics material.
15. The method of claim 14 comprising coextruding elastomeric material with the plastics material to form outer corners of the elongate body.
16. The method of any of claims 14 to 15 wherein the extruded cross-section comprises a projection on an opposite side of the elongate body to the channel which forms a smoke seal.
17. An edge-protecting device, for a door leaf, obtained by the method of any of claims 12 to 17.
18. A door leaf comprising a parallel front and rear faces bounded by edge faces which extend therebetween, wherein at least one of the edge faces is fitted with the edge-protecting device of any of claims 1 to 12 or 18.
19. A door comprising a door frame to which at least one door leaf of claim 19 is attached.