GB2165876A - Smoke-prevention doors - Google Patents

Abstract

A door frame 12 of a door 11 for a room or a building has a flexible sealing strip member 14 containing a magnetic strip 15 which cooperates with a metallic strip 16 on the door to provide a seal against the passage of smoke. Part of the seal, or a separate strip (43, Figure 4 not shown) may be of intumescent material. In an assembly with a pair of door leaves (Figure 3, not shown) the meeting edges are each provided with a flexible magnetic seal (34a, 34b). <IMAGE>

Description

SPECIFICATION Smoke-prevention doors and panels The present invention relates to a door or movable panel which is required to restrict or prevent the passage of smoke.

In the event of a fire, smoke will be created in large volume which constitutes a hazard to occupants. Smoke will pass freely through air gaps around doors. It is therefore common practice to incorporate in a door designated as a smoke stop door a strip or strips of flexible material in the edges or in the frame into which it is to be hung.

The intention of this provision is to cause sealing of the air gap between door and frame in normal use and its effect is to prevent the movement of smoke from its source to other parts of the same building.

Existing door seals are in the form of wiping seals, i.e. a brush pile or a flexible fin or compression seals. They suffer from the disadvantage that they suffer severe wear and tear during use such that not only can the sealing effect be impaired but also the seal can become so distorted that correct operation of the door is prevented. Moreover, they do not take up commonly accepted deviations in door leaf flatness.

It is well known to use, as sealing strips in refrigerator doors, a form of magnetic seal with a highly magnetic strip contained within a flexible carrier strip mounted on the inner face of the refrigerator door. The carrier strip is so designed as to enable the magnetic element to stretch the carrier when contact is made with the adjacent metal wall of the refrigerator. This action of stretching allows the seal to close off the air gap between door and frame. The functioning of this known arrangement depends on the adjacent wall of the refrigerator being constructed of a metal which is attracted by the magnetic strip.

The present invention seeks to provide a door or panel seal which has improved smoke-sealing properties compared to existing seals. It also seeks to provide a seal which is less susceptible to damage, whether accidental or intentional.

It is known to incorporate in the edges of a fire resisting door or in the frame in which it is to be hung, strips of intumescent material. The intention of this provision is to cause the sealing of the air gap between door and frame when high temperature reaches the strip, i.e. in the event of fire.

However, the combination of fire-resistant and smoke-sealing properties involves the problem that the incorporation of one property renders difficult the incorporation of the other property and may inhibit the correct operation thereof. Furthermore, such arrangements involve considerable expense.

Thus the present invention also seeks to provide a relatively inexpensive and convenient door or panel sealingly arrangement which combines smoke-stop and fire resistance properties.

According to a first aspect of the present invention there is provided a smoke stop door arrangement for a room or building comprising a door and a door-frame, at least one edge of one of which is provided with a flexible sealing strip member containing a magnetic strip and the other of which is provided with a co-operating metallic strip, whereby to restrict the passage of smoke between the door and the door-frame.

Preferably all four edges of the door are sealed.

Preferably the flexible sealing strip member is located in a recess. The metallic strip may also be located in a recess.

The arrangement may also be rendered fire resistant by the inclusion of intumescent material at the edge of the door. Thus the flexible sealing member and/or the magnetic strip or part of one or both may be made of intumescent material. Alternatively or in addition the flexible sealing member may include a separate strip or strips of intumescent material.

According to a second aspect of the present invention there is provided a smoke-resistant and fire-resistant arrangement comprising a door or panel and a frame therefor, one or more edges of one or both of which is/are provided with a flexible sealing strip containing a magnetic strip and the other of which is provided with 3 co-operating metallic strip, one or more of said strips and/or one or more further strips provided in or adjacent to one of sated first-mentioned strips comprising intumescent material.

In existing double door arrangements it is difficult to achieve a satisfactory seal arrangement where the doors meet. One possibility is to rebate the meetings edges of the doors so that they overlap each other when the doors are closed. However this necessitates the provision of a complicated mechanism to ensure that the doors close in the correct order. As mentioned above existing wiping-type seals in the form of brush piles or fins suffer from the disadvantage that they are likely to be distorted during use, thus rendering the seal ineffective. Furthermore they can also prevent the doors operating correctly, especially if settlement or warping occurs.

The present invention also seeks to provide a double-door sealing arrangement which provides an effective smoke-stop and does not interfere with the correct operation of the doors.

According to a third aspect of the invention, there is provided a smoke-stop door arrangement comprising two doors the meeting edges of which are each provided with a flexible sealing strip member containing magnetic material.

The sealing strip members are preferably housed in recesses in the edges of the doors.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 shows a sectional view of an arrangement in accordance with a first embodiment of the present invention comprising a door for a room or building and a frame in which it is hung; Figure 2 shows a similar sectional view of an arrangement in accordance with a second embodiment of the present invention; Figure 3 shows a sectional view of a double-door arrangement in accordance with a third embodiment of the present invention; Figures 4 to 7 show modifications of the seals of the arrangements shown in Figures 1 to 3.

Referring now to Figure 1, a prefabricated door 11 has a frame 12. The frame has a channel grooved into the door leaf rebate 13. Within the channel is set a complete flexible carrier unit 14, e.g. of PVC material, which contains a magnetic strip 15. Planted on or recessed flush with the surface or recessed flush beneath a decorative veneer of the door leaf in a position to interact with the magnetic seal is a metal magnetic or non-magnetic strip.

This arrangement is provided at each side edge of the door leaf and to the top and bottom edges.

In connection with the bottom edge the contact strip 16 is positioned in the floor surface.

Figure 2 shows a second embodiment of the invention in which the sealing arrangement is provided at the side surface of the door instead of at the edge of a major surface as shown in Figure 1.

The various parts are numbered as in Figure 1 with the addition of ten in each case.

Figure 3 shows a door assembly having a pair of door leaves 31a, 31b. The edges which meet each contain a complete unit 34a, 34b, Figure 3. The units take up a gap sufficiently wide to enable door leaves which swing both ways to pass each other.

The flexible nature of the carrier units 14, 24, 34a and 34b cause the magnetic force of the magnetic strip 15, 25, 35a and 35b, to stretch the carrier to the extent that normal operating air gaps aswell as commonly accepted deviations in door leaf flatness are automatically compensated when the door leaf is in a closed position.

The magnetic nature of the magnetic strips 15, 25, 35a and 35b ensures that a connection is made with contact strip 16, 26 or an opposing strip, Figure 3, when the door leaves are in a closed position to the extent that the air gap is eliminated and in the presence of smoke its passage is restricted to a level below that which will cause any hazard.

An advantage of the above-described arrangements is that they provide a more effective smoke seal than existing arrangements. In addition the provision of a recess for the seal ensures that it does not suffer appreciable damage, even with constant use of the door. Moreover the flexibility of the seal permits it to take up, without impairment of its function, distortions in door leaves which often occur, and for which there are recognised allowable tolerances. The provision of the metal strip permits the magnetic seal to function with doors (e.g. of wood) which would not otherwise be attracted by the magnet.

Various modifications may be made to the above arrangements. For example the metal strip 16, 26 may be magnetised and the strip 15, 25 may be of a metal attracted by the magnetic force of the strip 16, 26. The strip 16, 26 may be provided on the door frame and the recessed magnetic seal provided in the door. However, the invention is also applicable to doors and moving panels where the smoke seal is located elsewhere but has the same effect. In the double-door arrangement only one of the door leaves may be provided with a magnetic seal; the other door leaf may have a metal contact strip (as in Figure 1 or Figure 2) or a flexible carrier strip containing a non-magnetised metal strip.

To provide a combined fire-resistant and smokestop door arrangement one or more of the components of the seal may be intumescent and/or the flexible carrier strip may contain a strip of intumescent material. Thus the flexible carrier strip may itself be of an intumescent material; indeed PVC is itself intumescent at high temperatures. Alterna timely the strip 15 may contain intumescent material mixed with or bonded to the magnetic material. The intumescent carrier or magnetic strip is affected by high temperature caused by direct contact with fire. In the case of a magnetic and intumescent strip, it expands to the extent that the air gap continues to be eliminated even after the destruction of the flexible carrier strip. By this means the door may be rendered resistant to the passage of fire.

Figure 4 shows a seal in which a magnetic seal is contained within a flexible carrier 42, which also contains an intumescent seal 43.

Figure 5A shows a seal in which a magnetic seal 51 is contained adjacent to an intumescent seal 53 within a flexible carrier 52. This arrangement may be varied to provide the combination shown in Figure 5B, in which magnetic seal 51 is placed in front of an intumescent seal 53, within a flexible carrier 52 thus providing a fire resisting as well as smokestop functions. In a further modification (not shown) the magnetic seal is located behind the intumescent seal.

Figure 6 shows a hollow channel 61 which contains an intumescent material 62, in which is housed a magnetic intumescent or magnetic only seal and flexible carrier arrangement 63 as described in any of the above arrangements. In the case of a fire, the intumescent action is available to support the seal contained in arrangement 63, continues for a prolonged period and to provide continuing new intumescence as the encroachment of the fire increasingly heats the channel 61.

Figure 7 shows a metal contact strip 71 which forms part of a combination with an intumescenti magnetic strip 72. This combination may be itself contained in a hollow channel 73 which contains an intumescent material 74. This unit provides additional magnetic reinforcement to the metal contact strips and when contained within a hollow channel 73 provides additional intumescent reinforcement.

Seals in accordance with the invention may have more than one magnetic strip andlor more than one intumescent strip. The fire-resisting arrangements may be arranged to operate in two-stages.

This is achieved by having an intumescent strip, which intumesces at a relatively low temperature, and a further intumescent component (which may be, for example, the flexible carrier strip) which provides secondary, reinforcing intumescence at a high temperature.

Claims (13)

1. A smoke stop door arrangement for a room or building comprising a door and a door-frame, at least one edge of one of which is provided with a flexible sealing strip member containing a magnetic strip and the other of which is provided with a co-operating metallic strip, whereby to restrict the passage of smoke between the door and the door-frame.

2. An arrangement according to Claim 1, wherein all four edges of the door are sealed.

3. An arrangement according to Claim 1 or 2, wherein the flexible sealing strip member is located in a recess.

4. An arrangement according to any preceding Claim comprising intumescent material at the edge of the door.

5. An arrangement according to Claim 4, wherein at least part of the flexible strip member and/or the magnetic strip is made of intumescent material.

6. An arrangement according to Claim 4 or 5, wherein the flexible strip member includes at least one separate strip of intumescent material.

7. An arrangement according to any of Claims 4 to 6, wherein the flexible strip member and/or the metallic strip is housed within a channel containing intumescent material.

8. A smoke-resistant and fire-resistant arrangement comprising a door or panel and a frame therefor, one or more edges of one or both of which is/are provided with a flexible sealing strip containing a magnetic strip and the other of which is provided with a co-operating metallic strip, one or more of said strips and/or one or more further strips provided in or adjacent to one of said firstmentioned strips comprising intumescent material.

9. A smoke stop door arragement comprising two doors the meeting edges of which are each provided with a flexible sealing strip member containing magnetic material.

10. An arrangement according to Claim 9, wherein the sealing strip members are housed in recesses in the edges of the doors.

11. An arrangement according to Claim 9 or 10, wherein one or more of the components of the seal is intumescent.

12. An arrangement according to any of Claims 9 to 11, wherein the sealing strip members contain a strip of intumescent material.

13. A smoke-stop door or panel arrangement substantially as herein described with reference to any one of the accompanying drawings.