GB2232188A - Improvements in or relating to fire doors - Google Patents

Abstract

A fire door (1) made of fire resisting glass is mounted for opening and closing movement relative to a door frame (2). The door frame (2) comprises two substantially vertically extending side frame members (10) and (11) whose top ends are connected by a substantially horizontally extending top frame member (12). Each side frame member (10, 11) houses a plurality of pivotally mounted plates (16). In its normal, retracted position, each plate (16) is housed within its side frame member such that it does not project beyond its outer surface. However, when the door (1) is subjected to intense heat, the plates (16) move under gravity following the breaking of a fusable link to extend through a respective slot (15) outwardly of the corresponding side frame member. The extended plates (16) extend on both sides of the door (1) and thereby prevent or restrict deformation. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO FIRE DOORS The present invention relates to a frame member and to a fire door with an appropriate frame member.

Fire doors are doors which are made of material which can stand intense heat for an appropriate period of time whereby fire and the like can be held back by the door. Such a door needs to be biased into its closed position. In addition, it is important to ensure that the gap around the door between its edges and the door frame does not let through smoke and flame. To this end, fire doors are usually made to very close tolerances so that the gap between door and frame is kept as small as possible.

To date, fire doors made almost entirely of fire resistant glass have not met the appropriate criteria for many applications. This is because when one side of a glass door is subjected to intense heat it deforms and this considerably increases the gap around the door.

Thus, although fire doors fabricated of glass would be particularly useful in many situations, usually only doors with a small glass vision panel have been found to be suitable.

According to a first aspect of the present invention there is provided a frame member, extensible means supported by said frame member in a retracted position, and means for extending said extensible means to an extended position in response to predetermined phenomena, wherein said extensible means comprise at least two extensible elements which in the extended position project away from the frame member in the same direction and are spaced apart.

A frame member of the invention would be arranged adjacent the edge of a fire door, screen or the like such that when the extensible elements are in their extended position they project on either side of said door or screen. The extensible elements thereby prevent or restrict deformation of the fire door or screen.

Preferably, said means for extending said extensible means comprises means for holding said extensible elements in the retracted position against a biasing force, and releasing means for releasing said holding means such that the extensible elements are moved to the extended position by the biasing force.

In a particularly useful embodiment, the biasing force is provided by gravity, and said holding means are arranged to hold the extensible elements in the retracted position against the force of gravity.

However, it would alternatively be possible to provide biasing means providing the biasing force, for example spring means, against the force of which the extensible elements are held in the retracted position.

The releasing means may be arranged to lock the holding means and be arranged to release the lock in response to an appropriate signal. If required, the releasing means could be resettable. However, it is preferred that the releasing means comprise a fuse element which is either directly or indirectly responsive to said predetermined phenomena. For example, electrical means sensitive to the phenomena could be arranged to pass a current through the fuse element in response to the phenomena. Alternatively, the fuse element could be a heat sensitive fuse directly responsive to high ambient temperatures.

In one embodiment, the extensible elements are supported by a support bar which is held against the force of gravity by holding means including a fusible link. The link is arranged to melt or fuse when the ambient temperature exceeds a predetermined level whereby the holding means are broken and the support bar moves downwardly under gravity.

The extensible elements can be configured and shaped as required such that their projection or engagement around the edge of a door or screen prevents or restricts its deformation. For example, the extensible elements may be two spaced elongate members housed within the frame member, and arranged to project outwardly of and along one side of the frame member in the extended position. Alternatively, a plurality of individual extensible elements may be housed within said frame member and arranged such that, in the extended position, some of the elements are spaced from the rest of the elements. Thus, some of the elements would be on one side, and the rest of the elements would be on the other side of the edge of a fire door or screen arranged adjacent the frame member.Where there is a plurality of extensible elements it would generally be preferred that in the extended position, they be provided in two spaced columns extending along one side of the frame member. The elements in the two columns could be staggered relative to one another or each element in one column could be aligned with an element in the other column whereby, in the extended position, the elements are provided in spaced pairs.

In a preferred embodiment, each of said extensible elements comprises a plate having a substantially D-shaped configuration with a planar surface connected to a curved peripheral surface. Each of the plates is pivotally mounted within the frame member such that in the retracted position its planar surface does not project beyond one surface of the frame member and the plate is within the frame member. Upon extension, each plate is arranged to be pivoted such that its curved peripheral surface projects outwardly of the said surface of the frame member. Generally, said surface of the frame member would be provided with a slotted cover member, with a respective plate pivotally mounted within the frame member adjacent each slot, such that upon pivoting of each plate its curved peripheral surface projects through the corresponding slot.

The frame member could be arranged to extend along the free edge of a door for engagement with a door frame or with the adjacent free edge of an adjoining door.

One or more said frame members could also be incorporated into a door frame such that in the extended position the extensible elements extend on either side of the closed door. In a preferred embodiment two said frame members are arranged to extend substantially vertically and to form the side frame members of a door frame.

The present invention also extends to a fire door and door frame in which the door frame includes one or more frame members as defined above.

With this arrangement, it is possible to make the fire door out of fire resisting glass. For example, the fire door could comprise a glass panel supported in a frame, for example of steel. Said extensible elements would be arranged in their extended position to project on either side of the steel frame of the fire door.

An embodiment of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a partial elevation through a fire door and its frame embodying the present invention, the left hand side showing the arrangement with extensible elements retracted, and the right hand side showing the arrangement with extensible elements extended, Figure 2 shows a section along line II-II of Figure 1, Figure 3 shows a section along line III-III of Figure 1, Figure 4 shows an elevation of an extensible element, and Figure 5 shows a partial vertical section taken on the lines 7-of of Figure 1, The drawings show a fire door 1 arranged to be mounted for opening and closing movement relative to a door frame 2. The manner in which the door 1 is mounted relative to the door frame 2 is not illustrated in the drawings, but may be by any suitable means. In a preferred embodiment, the door 1 is provided with aligned top and bottom pivot pins (not shown) respectively engaged in a top portion of the frame 2 and in the floor to enable pivoting of the door 1 relative to the frame 2.

The door 1 is a fire door and therefore suitable closure means (not illustrated) are provided to bias the door 1 to its closed position within the frame 2. Where pivot pins mount the door, the closure means may comprise non-retention double acting springs arranged in the floor and connected with said bottom pivot pin. In this case, for ease of installation, the top pivot pin is preferably retractable.

The door 1 is preferably made of fire resisting glass. Although glass will withstand intense heat without igniting, in a fire situation in which fierce heat is applied to one side only of the door, the glass deforms. This causes gaps to appear around the door, between the door and its frame, through which smoke and flames can escape. As is described in detail below, the door frame 2 shown in the drawings incorporates extensible means 16 arranged to extend on both sides of the door 1 and thereby prevent or restrict its deformation.

In the embodiment illustrated, the fire door 1 comprises a panel 4 of fire resisting glass. For example, the panel 4 is 20mm thick and made of "Pyrostop" (trade mark). Each side edge of the glass panel 4 is received within a respective stainless steel, substantially U-shaped, side channel member 5. When the door 1 is installed within the frame 2 it will be appreciated that the side channel members 5 will each extend substantially vertically. Each of the top and bottom edges of the glass panel 4 is received within a respective substantially U-shaped channel 6 formed on a respective top and bottom rail 7. Each of the top and bottom rails 7 is preferably made of mild steel, and where the glass is 20mm thick, the rails are of the order of 40mm thick. It will be seen from Figure 5 that each of the rails 7 is hollow with its inwardly facing wall profiled to form the channel 6.

The glass panel 4 is secured to the side channel members 5 and to the top and bottom rails 7 by way of a layer of intumescent silicone 8 which is adhered to each of the edges of the glass panel 4 and to the base surfaces of the channels in which said edges are received. The layers 8 of silicone interposed between the side edges of the glass panel 4 and the base surfaces of the side channels 5 are preferably of the order of 5mm thick. The portions of the outer surfaces of the glass panel 4 which are adjacent its edges, and which are received within the channels of the side members 5 and of the top and bottom rails 7, are also secured to surfaces of the respective channels. In the embodiment illustrated, a ceramic tape 9 is interposed between the received portions of the outer surfaces of the glass panel 4 and facing surfaces of the channels.

For example, the ceramic tape 9 may be "Fibrefrax" (trade mark) tape.

The door frame 2 which surrounds three edges of the door 1 in the closed position thereof, comprises two substantially vertically extending side frame members 10 and 11 whose top ends are connected by a substantially horizontally extending top frame member 12. Each of said frame members 10, 11 and 12 comprises a channel section, preferably of mild steel, whose open side faces inwardly. It will be appreciated that said side frame members 10 and 11 extend substantially vertically with the open sides of the channel members facing one another. The open sides of the channel members 10, 11 and 12 are closed by an appropriate face plate 13 which is mounted to extend along the length of each of the channel members. Of course, the face plates 13 may be affixed to the channel members by any appropriate means.

In the embodiment shown a number of mild steel blocks 14 which have been drilled and tapped are stitch welded to the internal surfaces of each channel member, 10, 11 and 12 such that the face plates 13 may be screwed into position.

The two side frame members 10 and 11 are spaced apart to accommodate between their facing face plates 13 the width of the door 1. In this respect, as the door in its closed position is to act as a fire door, the gap between each side edge of the door 1, defined by the external surface of a side channel member 5, and the facing surface of the face plate 13 of the respective side frame member is kept as small as is possible. It will be seen, for example from Figure 2, that the depth of each of the side frame members 10 and 11 is considerably larger than the overall depth of the door 1 including its top and bottom rails 7. In this respect the rails 7 are considerably deeper than the glass panel 4. Furthermore, a horizontal axis X-X which extends centrally of the depth of the door 1 is also arranged to extend centrally of the depths of the side frame members 10 and 11.This means that the side frame members 10 and 11, and particularly their face plates 13 project relative to both of the external vertically extending surfaces of the door 1. The figures do not illustrate a cross-section through the top frame member 12, but it will be appreciated that it is generally identical to that of the side frame members 10 and 11.

A plurality of slots 15 are formed in each of the face plates 13 of the side frame members 10 and 11 as can be seen most clearly in Figures 2 and 5. In the embodiment illustrated, four pairs of slots 15 are provided in each face plate 13, the pairs of slots being spaced along the longitudinal extent of each face plate 13. All of the slots 15 in each face plate 13 are identical in size and positioning such that each pair of slots at a particular height in the face plate 13 of one of the side frame members faces a substantially identical pair of slots at the same height in the face plate 13 of the other of the side frame members. The slots 15 of each pair are spaced apart along the depth of the respective face plate 13 such that in the closed position of the door, the two slots 15 of one pair are arranged one on either side of the door as is apparent from Figures 2 and 5.

The side frame members 10 and 11 are arranged to house the extensible means 16 for preventing or restricting deformation of the door 1. In the embodiment illustrated each of the extensible means comprises a pivotally mounted plate 16 which is normally housed within a respective side frame member 10, 11 adjacent to a respective slot 15. In its normal, retracted position, each plate 16 is housed within its side frame member such that it does not project beyond the outer surface of the face plate 13. Thus, the plates 16 do not foul the door 1 during its normal opening and closing movements. However, and as will become clear below, when the door 1 is subjected to intense heat, the plates 16 are each arranged to be extended through the respective slot 15 outwardly of the corresponding side frame member.

In the illustrated embodiment a mounting block 17 is attached to the internal surface of the face plate 13 to extend between each pair of slots 15. A respective plate 16 is pivotally mounted on each end of the mounting block 17 such that each plate 16 is adjacent to a respective slot 15. Each plate 16 is also pivotally mounted to a substantially vertically extending side edge of a support bar 18 which extends within each side frame member 10, 11. In the normal position the support bars 18 are held against the force of gravity, by holding means described below, to maintain the plates 16 in their retracted positions.

Figure 4 shows an elevation of one embodiment of an extensible means 16 in the form of a plate. The plate shown in Figure 4 is substantially planar and has a substantially D-shaped configuration with a planar surface 25 connected to a curved peripheral surface.

This configuration defines a semi-circular portion 19 extended by an approximately trapezoidal portion 20. A pivot axis 23 which extends through each plate 16 and into a respective block 17 extends through the centre 22 of the circle defining said curved peripheral surface of the plate 16. A pivot axis 21 which extends through each plate 16 into the support bar 18 extends through a point 24 within the semi-circular portion 19 of the plate 16. The point 24 is spaced upwardly of the centre 22 as is shown in Figure 4. The left hand side of Figure 1 shows the plates 16 in their retracted position, and as can be seen, in this position, the planar surface 25 of each plate 16 extends in the respective slot 15 substantially flush with the face plate 13. The plate 16 is held in this position by way of the support bar 18.In the embodiment illustrated a recess 26 is formed in each plate 16 at the top of the planar surface 25. In the retracted position of the plate, the recess 26 is arranged to receive an edge of the face plate 13 defining the slot 15. This enables positive location of each plate 16 in its slot to ensure that the planar surfaces 25 of the plates 16 remain flush with the face plates 13. It will be appreciated that the tolerances to which the plates 16 and the slots 15 are fabricated are small so that the external appearance of the face plate 13 of the side frame members 10 and 11 will not be noticeably different from a normal door frame member because of the very small gap defined between each plate 16 and its surrounding slot 15.

In the retracted position, each support bar 18 is positioned to hold the pivot point 24 of each plate 16 connected to the bar above its central pivot point 22.

The support bar 18 is held in this position by way of holding means housed within the top frame member 12. In this respect, both of the support bars 18 within the two side frame members 10 and 11 are supported by a single length of wire 27. This wire might, for example, be 3mm thick steel wire whose length and path is chosen to hold both the support bars 18 in the position in which the plates 16 are retracted against the force of gravity.

As is clear from Figures 1 and 3, the wire 27 is attached to the top of one support bar 18 and passes upwardly and around a pulley 28 mounted within the top frame member 12 near the top of the respective side frame member 10, 11. The wire passes around the pulley 28, whereby its direction is changed, and then extends within the top frame member 12 to a further pulley 28 at the other end of the top frame member 12 adjacent the top of the other side frame member 11, 10. This second pulley 28 also changes the direction in which the wire 27 extends such that the other end thereof can be attached to the top of the other support bar 18. The central area of the wire 27 within the top frame member 12 is constrained to follow a tortuous path by way of two pulley wheels 29 and two guides 30.The pulley wheels 29 are preferably adjustable so that the length of the wire connecting the two bars 18 can be adjusted initially to position the bars 18 in the side frame members 10, 11 exactly where required. The central section of the wire 27 also incorporates two fusible links 31 which are heat sensitive. In its simplest form each fusible link 31 may be a small length of fusible material inserted within the length of the wire 27.

Normally, all of the plates 16 are held in their retracted position which is illustrated on the left hand side of Figure 1. Except when access is required, the door 1 remains closed under the biasing of its closure member. However, if a fire breaks out on one side of the door 1, the door and its frame become heated. When the increased temperature is at a predetermined level the fusible links 31 will melt thereby breaking the wire 27. This causes the support bars 18 to move downwardly under the influence of gravity. As the bars 18 move downwardly they rotate each of the plates 16 about its pivot axis 23 passing through its centre 22 whereby the semi-circular portion 19 of each plate 16 projects through its slot 15.When the pivot point 24 of each plate 16 has moved vertically downwards to a position in which it is spaced beneath its central point 22 the downward movement of the support bar 18 connected to that plate 16 is arrested. It will be appreciated that a pivoting movement of each plate through an angle between 90 and 1800 is achieved. At the end of this movement, each of the plates 16 projects beyond the face plate 13 of the respective side frame member 10, 11.

The plates 16 of each pair project on either side of the door 1. As the temperature on one side of the door 1 continues to rise, the glass 4 of the door will tend to deform. However, it will be appreciated that as the door 1 deforms in a direction perpendicular to its central axis X-X, its side edges will come into contact with one or more of the plates 16 which will prevent any further deformation of the door 1 in that direction.

The door 1 will also expand with the heat and such expansion will only increase the entrapment of the door between the extended plates 16. In this way, the gap between the side edges of the door 1 and the side frame members is prevented from increasing markedly and so the door is able to hold back flames for an appropriate period. In this respect, it is generally required that a fire door maintains its integrity for an hour.

The invention has been described above with reference to the particular embodiment of a fire door with its frame which has been illustrated. However, modifications and variations may be made as required.

For example, the number, location and spacing of the plates 16 may be chosen as required. Clearly it is not necessary that the plates be provided in pairs, it only being necessary that projecting means be provided on both sides of the door. Thus the plates to extend on one side of the door could be staggered relative to those on the other side. Where individual plates arranged to extend through slots are used, the particular shape of plate disclosed is useful as it enables the particularly efficient construction of the plates, support bar and holding means which is illustrated. However, the shape of the plates may be chosen as required and the means for causing their extension in case of fire can also be chosen as required. In some instances it may be that extensible means which can be extended when the temperature exceeds a predetermined level should be provided to extend from the top frame member alternatively to or in addition to those in the side frame members. In this case, the extensible members might be individually held in a retracted position by way of an appropriate fusible link, such that breaking of the link causes each one to fall into its extended position under the influence of gravity.

The door 1 as illustrated is a single door mounted in a door frame. However, it is frequently required to have double doors controlling a single door opening. In such an arrangement it would be possible to have extensible means provided in the free edge of one of a set of double doors for engagement with the adjacent free edge of the other door upon a rise in ambient temperature.

Instead of using individual plates as the extensible means, it may be preferred to utilise elongate strips arranged to project on each side of a door such that the gap between the door and its door frame is closed along a large part of its length.

In the illustrated embodiment, a particularly simple and reliable means for moving the extensible elements to their extended position in the event of a rise in temperature is proposed. That is, the plates are held in their retracted position against the force of gravity such that upon release of support, they adopt their extended position under gravity. Furthermore, in the illustrated embodiment the extensible elements in each side frame member are ganged together for collective movement. Other means of holding one or more elements in the retracted position, preferably against the action of appropriate biasing means can of course be employed.

The invention has been described above with particular reference to glass fire doors and this invention is particularly useful where it is required to make a fire door almost entirely of glass. Of course, the invention can be used with fire doors made of other materials, and also for windows, shutters and other closure members for openings.

It would also be possible to cause the extensible means to be extended in response to phenomena other than heat. For example, means to apply an electric current to a fusible means could be provided, said current applying means being responsive to the detection of an alarm condition and/or the detection of fumes, for example.

It will be appreciated that other variations and modifications can be made to the invention within the scope of the present application.

Claims (24)

1. A frame member, extensible means supported by said frame member in a retracted position, and means for extending said extensible means to an extended position in response to predetermined phenomena, wherein said extensible means comprise at least two extensible elements which in the extended position project away from the frame member in the same direction and are spaced apart.

2. A frame member as claimed in Claim 1, wherein said means for extending said extensible means comprises means for holding said extensible elements in the retracted position against a biasing force, and releasing means for releasing said holding means such that the extensible elements are moved to the extended position by the biasing force.

3. A frame member as claimed in Claim 2, wherein said holding means are arranged to hold the extensible elements in the retracted position against the force of gravity.

4. A frame member as claimed in Claim 2 or 3, wherein said releasing means are arranged to lock the holding means, and to release the lock in response to an appropriate signal.

5. A frame member as claimed in Claim 4, wherein said releasing means comprises a fuse element which is either directly or indirectly responsive to said predetermined phenomena.

6. A frame member as claimed in Claim 5, wherein electrical means sensitive to said predetermined phenomena is arranged to pass a current through the fuse element in response to said phenomena.

7. A frame member as claimed in Claim 5, wherein said fuse element is a heat sensitive fuse directly responsive to high ambient temperatures.

8. A frame member as claimed in any preceding claim, wherein said extensible elements are supported by a support bar which is held against the force of gravity by holding means including a fusible link, and wherein said link is arranged to melt or fuse when the ambient temperature exceeds a predetermined level whereby the holding means are broken and the support bar moves downwardly under gravity.

9. A frame member as claimed in any preceding claim, wherein said extensible elements are configured and shaped such that in their extended position they are arranged to engage with the edge of a door or screen and prevent or restrict its deformation.

10. A frame member as claimed in any preceding claim, wherein said extensible elements comprise two spaced elongate members housed within the frame member, and arranged to project outwardly of and along one side of the frame member in the extended position.

11. A frame member as claimed in any of Claims 1 to 9, wherein a plurality of individual extensible elements are housed within said frame member and arranged such that, in the extended position, some of the elements are spaced from the rest of the elements.

12. A frame member as claimed in Claim 11, wherein in the extended position, the extensible elements are provided in two spaced columns extending along one side of the frame member.

13. A frame member as claimed in Claim 11 or 12, wherein each of said extensible elements comprises a plate pivotally mounted within the frame member such that in the retracted position the plate is within the frame member.

14. A frame member as claimed in Claim 13, wherein each said plate is arranged to be pivoted such that part thereof projects outwardly of the said surface of the frame member.

15. A frame member as claimed in Claim 13 or 14, wherein each said plate has at least one substantially planar peripheral surface connected to a curved peripheral surface.

16. A frame member as claimed in any preceding claim, arranged to extend along the free edge of a door for engagement with a door frame or with the adjacent free edge of an adjoining door.

17. A door frame incorporating one or more frame members as claimed in any preceding claim.

18. A fire door and door frame in which the door frame includes one or more frame members as claimed in any preceding claim.

19. A fire door and door frame as claimed in Claim 18, wherein one or more said frame members are incorporated into the door frame such that, in their extended position, the extensible elements extend on either side of the closed door.

20. A fire door and door frame as claimed in Claim 18 or 19, wherein two said frame members are arranged to extend substantially vertically and to form the side frame members of a door frame.

21. A fire door and door frame as claimed in any of Claims 18 to 20, wherein said fire door is made out of fire resisting glass.

22. A fire door and door frame as claimed in Claim 21, wherein said fire door comprises a glass panel supported in a frame of steel.

23. A frame member substantially as hereinbefore described with reference to the accompanying drawings.

24. A fire door and door frame substantially as hereinbefore described with reference to the accompanying drawings.