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Publication numberUS2927353 A
Publication typeGrant
Publication dateMar 8, 1960
Filing dateMar 1, 1957
Priority dateMar 5, 1956
Publication numberUS 2927353 A, US 2927353A, US-A-2927353, US2927353 A, US2927353A
InventorsSnitker Jens Christian
Original AssigneeS O S B Skod I S
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fire-retarding door
US 2927353 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

United States Patent FIRE-RETARDING DOOR Jens Christian Snitker, Risskov, Denmark, assignor to 5.0.2; B-Skod I/S, Aarhus, Denmark, 2 Danish partners p Application March 1, 1957, Serial No. 643,361

"Claims priority, application Denmark March 5, 1956 1 Claim. (Cl. 2035) The invention relates to a fire-retarding door made of fa board, consisting of wooden material wherein incombustible material has been inlaid.

When the incombustible material has been inlaid in :an expedient manner in the wooden material of the board, such door will be capable of resisting a fire for a rather long time, so that it can be used as a front door for flats in multi-storied houses so as .to prevent a fire from spreading rapidly from the staircase to the flats or vice versa. Furthermore the door can be designed without difliculties in such a way that it hardly can be distinguished from an ordinary door. Also public buildings and hospitals will provide an extensive field for the use of such a door.

The board constituting the door will be capable of resisting a fire for half an hour or more, which has been ascertained by tests carried out in accordance with the international norms. When using the board as a door in connection with dwelling flats and elsewhere as mentioned in the foregoing, it would be expedient if also the furnishing ordinarily used for doors, such as hinges, locks, panes and the like fittings of heat-conducting material, could be used without the formation of such furnishing of paths, by which the heat and consequently the fire can easily advance, and also that especially the insertion of panes in the door should be possible, all in substantial accordance with the prevailing practice. By the present invention this is made possible.

In accordance with the above stated the main object of the invention is to provide a fire-retarding door for dwelling houses, public buildings and hospitals, which has a neat appearance and fufills aesthetical requirements.

Another object of the invention is to indicate a door of the above kind which can be provided with ordinary fittings of heat-conduction material without impairing its ability to resist fire.

A further object is to provide a fire-retarding door which can be produced at approximately the same expenses as an ordinary wooden door.

With the above and other objects in view the present invention consists in the combination and arrangement of parts, hereinafter more fully described, illustrated in the accompanying drawings and more specifically pointed out in the claims, it being understood that changes may be made in the form, size, proportions and details of construction without departing from, or sacrificing any of the advantages of the invention.

The invention will be explained in detail in the following, reference being had to the drawing, wherein:

Fig. l is a side view of a door with surrounding frame,

Fig. 2 is a section at a larger scale through part of the door at an aperture, wherein a pane has been inserted, the section being taken on the line IIII in Fig. 1,

Fig. 3 is a section through the door on the line III-III in Fig. l, where a hinge is provided, and

Fig. 4 is a section through the door on the line IVIV in Fig. 1, where a lock with handles is provided.

In all the embodiments shown, the door is made of 'ice two layers of wood 10 and 12, between which a protection 14 against burning through is inserted, see Figs. 2-4. This protection may e.g. consist of heat-insulating incombustible material, preferably asbestos, arranged in the wood in two layers, or zones, in such manner that in each layer, or zone, bodies of wood are enclosed by said material, the bodies of wood in one layer being displaced in relation to those in the other layer. Between these two layers or zones is interposed a continuous layer of wood. Hereby is obtained that the connection between adjoining layers always can be performed by gluing wood to wood so that no cleavage will occur between the individual layers, even under intense influence of heat. In case of fire at one of the sides of the door, the spreading of the fire through the door will be retarded or stopped by the protective layer 14. I

In the door is provided an aperture 16, wherein there is inserted a pane 18, consisting of glass with inlaid wire mesh 20, see Fig. 2. Along the circumference of the aperture 16 a rebate has been made with faces 22 of special shape, as appears from the figure. The pane is secured by means of a list 24 extending along its margin. The faces 26 of the said list, which confronts the pane, have a shape similar to that of the faces 22. The space formed between the faces 22 and 26 is filled with an incombustible material 28, which may e.g. be a slurry of asbestos fibres, the fluid component of which is waterglass. The latter acts as a binding agent between the asbestos fibres themselves and betwen the fibres and the wood. The pane 20 is so inserted in the material 28 that its margin on either side and its edge are surrounded by the material. It is expedient that the pane 18, as shown, is in the same plane as the protective layer 14. By shaping the faces 22 and 26 as indicated above is obtained that the thickness of the incombustible material 28 is increased at the edge of the wood, which limits the aperture 16, whereby the resistance against fire is increased.

The presence of Water-glass in-the incombustible material has proved to provide a good adhesion of the said material to the wood. Therefore, it is not necessary to secure the list 24 by means of screws. When the wood at one or the other side of the pane margin burns away, the incombustible material will remain undamaged, and the connection of this material with the wood on the opposite side will be secured by the content of Water-glass, so that the pane does not fall out.

The door will normally be covered with veneer on either side. For aesthetical reasons it may be expedient to place a layer of veneer also on the incombustible material 28 at the aperture 16. This has not been shown in the figure.

Instead of asbestos, other refractory materials, e.g.' inorganic substances, preferably of mineral origin, such as mica, kieselguhr, kaolin, and fireclay, may constitute the solid component of incombustible material. The refractory material should have a high capacity for heat insulation.

In Fig. 3 a hinge flange 30 is attached to the edge of the door by means of screws 34. Between the hinge flange and the material of the door, a strip 36 of incombustible material, e.g. asbestos, has been inserted.

In Fig. 4 the numeral 38 denotes a door lock, which is received in a recess 40 at the edge of the door. The recess is so dimensioned that space is provided for a lining 42 of incombustible material between the lock 38 and the surrounding Wood. This material 42 may consist of asbestos sheets or asbestos strips or of an asbestos slurry as mentioned in connection with Fig. 2. In Fig. 4 44 designates the foremost end of the bolt, which is actuated in the usual way by turning a quadrangular bar as such, such as hinges, locks, panesor the like.


The'numeral 50 denotes annular rosettes screwed on t m 9min. pp r p t handles 4-3- i a? srsz ette consist of 1m tal'," rings of; a

The inire iw m y fin s-ethe p scatiop lhan thes r l l rate f n 'qQ 'i w Q w t he i h wm emb dimen 'It is preferably to be used for all sil ch fittings or other Pa Q h a q zd et n wvr nate ia w c ccupy pa between the;two side faces. of ilie 1100110 1 extend into h din b we n th d o an t Sl II HQQl Q lfH hfiwbedsn ma e ial the b a b n u a woo a a We as-mat t fl sub tuting. 19b: .tb dle-l wo d fib bo rd- V V 'Itl t b aa sxs qq tha th leapr ssion .v u r shiagi 1 1 sed in th eforegoing specificatign and in tl e appended cl m o e a es ew 9 heat cendg tin ma er which are suitable or necessary Jf r theuseof thedoor 46, to the ends of Which 'tliedoor handles 48l ave been 7 test; zg rm y' esi I claim:

' A"fire-retarding door consisting of two layers of wooden material forming the side faces of the door, a non-metallic protective material for protection against fire arranged centrally between said layers of wooden material, said non-metallic'nniaterial incorporating incombustible heateinsulating materialextending to the edges-of the door, hin ges'of metal connected to one edge f th 53 091, fittipszoiiincqmbllstibleheat-insulating material inlaid betweensaid-hinges and said edge of theidoor,

and a door lock of metal inserted in a recess atfthe opposite edge of thefdo or, said lock being. embedded intincom bustibleheat-insulating material.

References Qit ed inthe ijletof this patent V

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US570391 *Mar 31, 1896Oct 27, 1896 Fireproof door
US826549 *Mar 3, 1905Jul 24, 1906Gilmour Door Company LtdFireproof door.
US2593050 *Jan 24, 1952Apr 15, 1952Owens Illinois Glass CoComposite fire door
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4573287 *Jan 19, 1984Mar 4, 1986Rolscreen CompanyDouble opening exterior french door and door improvements
US4738054 *Nov 18, 1985Apr 19, 1988Milcor IncorporatedCeiling access door assembly
US5916077 *Feb 20, 1997Jun 29, 1999Chuan Mau Products, Ltd.Composite fire-proof, heat-barrier door
US20060283143 *Jun 15, 2005Dec 21, 2006York International CorporationFrameless viewport
U.S. Classification49/394, 49/501, 49/399
International ClassificationE06B5/10, E06B5/16
Cooperative ClassificationE06B5/16, E06B2003/7034
European ClassificationE06B5/16