In particular, but not exclusively, the present invention relates to a combined smoke and fire seal which is intended to be sited in the corner of a rebate of a door frame for co-operation with the side and/or end face of a door.

According to one aspect of the present invention there is provided a combined smoke and fire seal comprising an elongate body formed from an intumescent material to define a fire seal and at least one elongate flange extending along the length of the body and projecting laterally therefrom to define a smoke seal, the elongate body and flange being integrally connected to one another.

Preferably the elongate body and flange are co-extruded so as to be integrally connected.

Preferably the exposed surfaces of the body not covered by said flange are provided with a protective covering.

Preferably the protective covering comprises a co-extruded plastics sheath.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which:- Figure 1 is an enlarged cross-sectional view of a first embodiment according to the present invention;

Figure 2 is a view similar to Figure 1 showing the first embodiment located in situ; Figure 3 is an enlarged cross-sectional view of a second embodiment according to the present invention; Figure 4 is a view similar to Figure 3 showing the second embodiment located in situ; Figure 5 is an enlarged cross-sectional view of a third embodiment according to the present invention; Figure 6 is a view similar to Figure 5 showing the third embodiment in situ.

Referring initially to Figure 1 there is shown a combined smoke and fire seal 10 according to a first embodiment of the present invention.

The combined smoke and fire seal 10 includes a fire seal in the form of an elongate body 12 which is preferably extruded from an intumescent material which provides the desired amount of expansion on intumescence. A suitable intumescent material is a compound consisting of intercalated graphite flakes in a matrix of polyvinyl chloride. The polyvinyl chloride may be flexible or rigid.

The body 12 shown in Figure 1 is of strip-like form which, in cross- section, is cranked to define two arms 14,15. Typically, this strip-like form has a thickness of about 1 mm Each arm 14,15 has a terminal edge face 16,17 respectively to which a respective resilient flange, or seal lip 18,19 is integrally connected. The seal lips 18,19 define smoke seals.

Preferably each seal lip 18,19 is extruded from a soft elastomeric material and is co-extruded with the body 12 so as to integrally bond the seal lip 18,19 to the respective end face 16,17 of the body 12.

The soft elastomeric material is compatible with the intumescent compound to enable both to be co-extruded and form an integral connection.

The elastomeric material also provides a seal lip having the desired degree of flexibility relative to the body 12 and resilience to enable the lip to recover to its original shape after being deformed by engagement with a door in use.

As seen in Figures 1 and 2 each seal lip 18,19 is inclined to the respective arm 14,15 so as to extend toward one another.

Accordingly, as indicated in Figure 2, when the combined smoke and fire seal 10 is located in the corner of the rebate 30 of a door frame 31, the outer face of each lip seal 18,19 is positioned at an acute angle 0 relative to the edge face 34 and front face 35 respectively of the door 36.

Thus when engaged by the door 36 the lip seals 18,19 are deflected inwardly toward the body 12.

Preferably, the base or root portion 37 of each lip seal 18,19 is relatively thicker than the remainder of the lip seal. This is preferred as it increases the resilient bias of the remainder of the lip seal 18,19 into contact with the door 36.

Optionally, the exposed surfaces of the body 12 which are not covered by the lip seals 18,19 are covered by protective coverings 40,41.

Protective coverings 40,41 are preferably formed from a suitable thermoplastics material which enables the intumescent to burst through in the event of a fire, such as polyvinylchloride. The coverings 40,41 are preferably co-extruded with the body 12 so as to be integrally bonded therewith in face to face contact. The thermoplastics material for forming the coverings 40,41 is preferably compatible with the intumescent material and the elastomeric material so as to form an integral connection therewith when co-extruded.

Preferably, in order to secure the combined smoke and fire seal 10 in position in the rebate 30, layers 46,47 of a pressure sensitive adhesive are provided. Prior to installation, layers 46,47 are preferably covered by a release covering.

A second embodiment 50 is illustrated in Figures 3 and 4.

In the second embodiment 50, the fire seal body 12 is in the form of a strip 52 which in section is planar and which is extruded from the intumescent material referred to above. A single resilient seal lip 55 is provided which is co-extruded with the strip 52 so as to be integrally connected at its opposite sides to opposite edge faces 56,57 of the strip 52.

Accordingly, the seal lip 55 forms a hollow bulbous seal for contacting the outside face of the door.

In the second embodiment the seal lip 55 covers the internal face of the strip 52 and so an additional covering is not provided.

The outer face of the strip 52, is in use protected by the surface to which it is attached and so, in the illustrated example, no additional covering is provided. Accordingly a layer 47 of pressure sensitive adhesive is provided in direct contact with the outer face of the strip 52.

In the third embodiment 60, the fire seal body 12 is again in the form of a planar strip 61 which is extruded from the intumescent material referred to above.

The embodiment 60 includes a smoke seal 62 extruded from a suitable resilient material and is co-extruded with strip 61 so as to be integrally connected to the end face 64 of the strip 61. The seal 62 is preferably of arcuate cross-section as seen in Figure 5.

The remaining faces of body 12 are covered by a casing 70 which is preferably co-extruded with the strip 61.

The casing 70 is preferably formed from a suitable plastics material, such as polyvinylchloride which enables the intumescent material to break through in the event of a fire. The casing 70 includes a relatively rigid flange 72 having integrally formed barb-like ridges 73. The flange 72 is intended to be inserted into a groove 75 formed in the door surround in order to secure the combined smoke and fire seal in position.

It will be appreciated that since the body 12 is of strip-like form and of relatively small thickness, the combined smoke and fire seal may be surface mounted in the usual rebate of a door frame without requiring an additional recess to accommodate the main body of the seal.