GB2270495A

GB2270495A - Doors

Info

Publication number: GB2270495A
Application number: GB9218971A
Authority: GB
Inventors: Kevin D S Towler; Rupert Scott
Original assignee: Timber Technology Ltd
Current assignee: Timber Technology Ltd
Priority date: 1992-09-08
Filing date: 1992-09-08
Publication date: 1994-03-16
Also published as: GB9218971D0

Abstract

A door comprising an interior fabricated from non metallic components, at least the faces of which are covered by metal skin 16. The interior comprises a framework manufactured from cement chipboard carrying a panelling comprising a composite fibrous material and a covering, on each side of the door, of a fire resistant material, e.g. calcium silicate board. <IMAGE>

Description

Improvements in or relating to Doors The present invention concerns improvements in or relating to doors, particularly but not exclusively fire resistant doors.

The advantages of fire resistant doors in containing a fire to a particular room or area in a building thereby facilitating the evacuation of personnel from other areas is well recognised.

Currently there are two main types of doors utilised to provide fire resistant barriers. In the main, these doors are either wooden doors mounted in wooden frames or hollow metal doors mounted in metal frames.

Each of these types of door provides a different type of barrier to a fire contained by the door and its associated frame. A metal door and frame set, for example, expands and moves in a particular way when heated and the door designer attempts to design the door and door frame such that the relative movements are compatable and distortion of the doors and gaps between door and frame are restricted for as long as possible, thereby maintaining the fire barrier. On the other hand, a wooden door and frame combination acts in a different manner. It is less likely to move but obviously more likely to be charred and the design of the door is intended to a large measure to control the effect of charring for the longest possible time.

Clearly, each of these doors have advantages and disadvantages, for example, a metal door, while providing an efficient fire barrier may not be aesthetically pleasing. Further it may provide relatively low heat insulation. Similarly a wooden door may be unsuited for a particular location, for eample it offers relatively low security.

It is an object of the present invention to obviate or mitigate those and other disadvantages.

The present invention provides a door comprising an interior fabricated from non-metallic components at least the faces of which are covered by metal skin.

Preferably the interior comprises a framework manufactured from cement chipboard carrying a panelling comprising a composite of a fibrous material and a covering, on each side of the door, of a fire resistant panel. The fire resistant panel is preferably a calcium silicate sheet. Preferably an additional calcium silicate sheet extends over both faces of the panelling.

Preferably the metal skin of the door is fabricated from stainless steel which extends across the entire area of the door faces and over its edges, that part of the sheet extending over the edges being of double thickness.

Preferably the sheet extending over the door edges defines a space therebetween in which is positioned an intumescent seal. The intumescent seal may include also a smoke seal adapted for inter-engagement between the door and the surrounding frame or adjacent door of a door pair.

Preferably the door includes a frame to which it is hinged, said frame comprising a non-metallic interior and a metallic skin. The interior preferably comprises a wood infill faced on its edge adapted to receive the hinge by a calcium silicate sheet. The frame may include also a plasteboard infill.

An emdobiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Fig. 1 shows an elevation of a double door assembly; Fig. 2 shows a sectional partial plan on the line II-II of Fig. 1; Fig. 3 shows a partial sectional plan on the line 111-111 of Fig. 1; Fig. 4 shows a partial sectional elevation through the top of a door and its frame, where no overpanel is provided; Fig. 5 shows a partial sectional elevation on the line V-V of Fig. 1; and Fig. 6 shows a partial plan on the line VI-VI of Fig. 1.

The door set illustrated in Fig. 1 comprises an assembly of two door leaves hinged along their opposite edges, a door frame and an overpanel. It will be realised, however, that the invention is equally applicable to door sets comprising only one leaf and a surrounding frame and any other combinations currently employed in the construction of doors.

The door set illustrated in Fig. 1 comprises two door leaves 10 each carried by hinges 50 on a framework 30 which supports also an overpanel 20.

The doors, frame and overpanel are each faced by 0.7 mm stainless steel and each comprise an interior fabricated from a number of fibrous and non-metallic components.

Fig. 2 shows a section through the door set at a hinge 50. The door is made up from an interior comprising a framework of five star cement chipboard 13 which is cut from a sheet of chipboard so that the face of the chipboard (as opposed to its edges) is presented to the edge of the door 10. The chipboard thus receives more efficiently the hinge screws (not shown). A rectangular cross-section channel is machined into the inner face of the frame to form a groove which accepts a tongue formed in the interior panelling 11 of the board which is formed from 500 kg/m3 flaxboard, that is, a composite board made from flax fibres held together by a binder and filler material.

The thickness of the flaxboard panelling is less than the thickness of the frame and the recess in the interior defined by the faces of the flaxboard and the interior edges of the frame are each filled with a sheet of calcium silicate 12. A further sheet 14 of calcium silicate extends over the entire front and rear faces of the door interior, the fixing of the calcium silicate board being achieved by the use of a suitable adhesive.

Finally each side of the door interior is provided with a facing of plywood 15 the thickness of which is calibrated to give the required overall thickness dimension for the door interior.

A 0.7 mm thick stainless steel sheet 16 is then applied to the faces of the door and extends in a double thickness layer 17 over substantially the outer thirds of the door edges. The gap defined between these double thickness layers 17 is filled by an intumescent seal strip 40 which is accommodated in a recess machined in the outer edge of the cement chipboard framework. The seal strip includes a deformable smoke seal 42 filling the gap between the door leaf 10 and the frame 30 when the door is closed.

In general terms the door frame has a similar construction in that it comprises an outer stainless steel casing 34 which surrounds the fabricated interior comprising a maple frame member 31, the face of which adjacent the hinge 50 has a calcium silicate sheet cover 33 -Plasterboard sheets 32 provide the infill for the remainder of the frame interior. The stainless steel sheet 34 on the frame member and the sheet 16 on the door is recessed to accommodate the hinge 50, the hinge recess including also a fire resistant sheet 43 (Fig. 3).

Fig. 3 illustrates a fixing bolt 51 passing through the maple infill 31 into surrounding block work 35, the bolt hole in the sheet being covered by a stainless steel grommet 52 after the bolt has been fitted. The framework is bedded against the blockwork 35 by use of a fibrous blanket 44 the edges of which are covered by silicone sealant 43.

Fig. 4 illustrates the top and bottom of the door and shows that the double thickness wrap-over 17 does not extend over the top and bottom edges.

Fig. 6 shows the construction of the door edge remote from the hinged edge and Fig. 5 illustrates that the overpanel 20 is constructed in essentially the same way as the door from a framwork of five star cement chipboard 13, flaxboard panelling 11, calcium silicate board 12,14, plywood 15 and stainless steel sheeting 16.

The door of the present invention combines the advantages of a timber door with the advantages of a steel door. A combination of the use of hardwood timber, cement chipboard and flaxboard, provides better resistance to charring, and these are further enhanced by the use of calcium silicate board which, in itself, is not sufficiently structurally stable to provide the entire door interior. The use of wood in the door frame and the composite wood in the framework of the door interior means that door furniture, for example, hinges, handles, locks, self closers, etc. can be mounted to the door by conventional methods with relatively little difficulty thereby easing the installation and maintenance of the door set.

Various modifications can be made without departing from the scope of the invention, for example, alternative materials can be utilised for constructing the non-metallic interior and the outer skin of the door, depending on its required fire rating. Different construction techniques can be employed, for example, the interior frame can be fabricated in different ways and the panelling and calcium silicate board facings can be applied utilising different constructional techniques.

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

Claims

Claims:

1. A door comprising an interior fabricated from non-metallic components at least the faces of which are covered by metal skin.

2. A door according to Claim 1, wherein the interior comprises a framework manufactured from cement chipboard carrying a panelling comprising a composite of a fibrous material and a covering, on each side of the door, of a fire resistant panel.

3. A door according to Claim 2, wherein the fire resistant panel is a calcium silicate sheet.

4. A door according to Claim 3, wherein an additional calcium silicate sheet extends over both faces of the panelling.

5. A door according to Claim 1, 2, 3 or 4, wherein the metal skin of the door is fabricated from stainless steel which extends across the entire area of the door faces and over its edges, that part of the sheet extending over the edges being of double thickness.

6. A door according to Claim 5, wherein the sheet extending over the door edges defines a space therebetween in which is positioned an intumescent seal.

7. A door as claimed in Claim 6, wherein the intumescent seal includes also a smoke seal adapted for inter-engagement between the door and the surrounding frame or adjacent door of a door pair.

8. A door set comprising a door as claimed in any of Claims 1 to 7 and a frame to which said door is hinged, said frame comprising a non-metallic interior and a metallic skin.

9. A door set as claimed in Claim 8 wherein the interior comprises a wood infill faced on its edge adapted to receive the hinge by a calcium silicate sheet.

10. A door set as claimed in Claim 8 or 9 wherein the frame may includes also a plasterboard infill.

11. A door substantially as herein described with reference to and as shown in the accompanying drawings.

12. A door set substantially as herein described with reference to and as shown in the accompanying drawings.

13. Any novel subject matter or combination including novel subject matter herein disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.