A FIRE RESISTANT WINDOW CONSTRUCTION

Abstract: An openable multi-pane window of fire resistance class F 60 having a window frame (2) and mutually connected window sashes (4, 6, 8), in which a single pane of borosilicate-fire resistive glass (16) is fitted into a metallic outer sash (4) on the outward side of the window, and a two-pane sealed glazing unit (18) is fitted in an inner sash (8) on the inward side of the window. The window frame (2) and the inner window sash (8) are made of wood, and a metallic clamping frame (20) is fitted in the inner sash. The glazing unit (18) is clamped firmly along its edges in the metallic clamping frame by means of an adjustable clamping force effected through the medium of tightenable clamping screws (54). The glazing unit (18) includes a borosilicate-fire resistive glass (22) and a pane (24) of conventional window glass on the inward side of the glazing unit. The freely exposed surfaces of at least the wooden window frame (2) and the wooden inner sash (8) on the inside of the window are coated with a fire resistive paint. The invention also relates to a fixed multi-pane window construction in which a glazing unit is firmly clamped through the action of adjustable clamping pressure in a metallic clamping frame which is fixed to the window frame.

Description: A fire resistant window construction The present invention relates to an openable multi-pane window construction, particularly a multi-pane window of fire resistance Class F 60, the glazed framework of which includes a window frame and mutually connected window sashes, and in which construction a single pane of glass is fitted in an outer sash on the outward side of the win¬ dow construction, and an inner glazing unit which compri¬ ses at least one pane of glass is fitted in an inner win¬ dow sash on the inward side of the window construction. The invention also relates to a fixed multi-pane window construction, particularly a multi-pane window of fire resistance Class F 60, the glazed framework of which con¬ struction includes a window frame which has a glazing unit ' fitted therein. In the case of internal fires in building structures it is the windows and other glazed structural members which are the least fire resistive and the least able to prevent the fire from spreading. Special-duty window constructions (of fire resistance Class F 30) which are capable of resisting a normal fire for a little more than 30 minutes are known to the art. There is a surprisingly wide demand, however, for window constructions which are fire resistive over much longer periods of time, since the walls of a building will nor¬ mally withstand the effects of fire for much longer time periods than 30 minutes; wall structures are often able, to stand up to the effects of fire for twice this length of time, i.e. one hour. The only possibility hitherto of achieving long fire resistance times with building window constructions, is by using non-openable (so-called fixed) window constructions that are comprised of steel or some other material having hig fire resistance. These known window constructions, however, are both clumsy in appearance and expensive to manufacture. The object of the present invention is primarily to provi- de an openable multi-pane window with which the window frame and at least the inner sash are made of wood, and which can resist a "standardized" fire for at least a period of one hour (i.e. fulfills the requirement of fire resistance Class F 60), so that the window construction will fulfill the same fire resistance requirements as those fulfilled by the walls of the building in which the window construction is installed. By "standardized" fire is meant here a carefully specified artificial fire created by means of oil burners, in an accurately specified test room in a wall of which the win¬ dow construction in question is installed. The artificial fire is specified primarily with regard to the rise in room temperature as a function of the time over which the fire has continued. In this regard the temperature increa¬ ses by ca 550°C during the first five minutes, passes 650°C after ca 10 minutes, 700°C after ca 13 minutes, 800°C after ca 26 minutes, and 900°C after ca 50 minu¬ tes, and reaches a temperature somewhat higher than 920°C after 60 minutes. The aforesaid objects are achieved with a window construc¬ tion of the aforedescribed kind in that the window frame and the inner sash are made of wood, there being mounted in the inner sash a metallic clamping frame in which the inner glazing unit is firmly clamped along the edges thereof through an adjustable clamping force; both the single pane of glass and a glass pane ^ of the inner glazing unit are made of plain, heat hardened borosilicate-fire p resistive glass, such as Pyran glass ; the outer sash consists of a metal frame in spaced relationship with and located outwardly of the wooden inner sash; and the freely exposed surfaces of at least the wooden window frame and the wooden inner sash on the inward side of the construc- tion are provided with a coating of fire resistive paint. The glazing unit on the inward side of the window con¬ struction may comprise a sealed glazing unit which, in addition to the pane of borosilicate-fire resistive glass also includes a pane of conventional window glass which is located on the inward side of the unit in spaced relation¬ ship with the pane of fire resistive glass. Alternatively, the glazing unit may include on the inward side of the construction solely a single glass pane which is made of plain, i.e. non-reinforced, heat hardened boro¬ silicate-fire resistive glass and which is laminated with, e.g., a sheet of low emissive glass. The inventive window construction is thus a multi-pane window, preferably a three-pane window, which incorporates a pane of plain, heat hardened borosilicate-fire resistive glass on both the outside of the construction and on the inside of the glazing unit. In addition to the fire resistive properties afforded by the two borosilicate-fire resistive glass panes, the inventive window construction is also imparted fire resis¬ tive qualities by the metallic clamping frame and by the fire resistive paint applied to the wooden window frame and to the wooden inner sash on the inward side of the construction. When heated to elevated temperatures (for instance temperatures of 150°C - 170°C) the fire resistive paint swells in the manner of a "souffle" there- with forming a heat insulating layer which protects the underlying wood. The fire resistive properties of the window construction can be further enhanced with the aid of fire-swelling strips and jointing compounds and non-combustible seals in the construction. Such further developments of the inven¬ tion are set forth in particular in claims 4 and 6. A suitable construction of the metallic,clamping frame is specified in particular in- claims 5 and 6. The window con- struction according to the invention can also include a wooden, intermediate sash, as set forth in claim 7. When the mutually connected window sashes are pivotally hinged and held in the window frame by means of hinge devices located between the window frame and the inner window sash, the window construction may conveniently include means which provide a connection which will hold - the sashes in the window frame when the normal sash retai¬ ning function of the hinges ceases. This can be achieved, for example, in accordance with the arrangements defined in Claims 8 and 10 respectively. The fire resistive properties of the window construction can be further enhanced by suitable selection of material dimensions, in accordance with Claim 9. The concept of the invention is not restricted solely to openable window constructions in accordance with Claims 1-10, but can also be applied to a fixed multi-pane window construction according to Claim 11. The present invention affords, with the aid of simple means, window constructions of fire resistance class F 60 which exhibit extremely good properties with regard to imperviousness, k-values and mechanical strength. The invention will now be described in more detail with reference to a number of embodiments thereof and with reference to the accompanying drawings, in which Fig. 1 is a perspective, cross-sectional view of a three- pane fire window constructed in accordance with the inven¬ tion and comprising mutually connected window sashes and a two-pane sealed glazing unit; Fig. 2 is an enlarged vertical sectional view of the win¬ dow construction illustrated in Fig. 1; Fig. 3 is a horizontal sectional view which shows the hinge side of the window construction illustrated in Fig. 1; Fig. 4 is a cross-sectional view in still larger scale of the metallic clamping frame of the window construction illustrated in Figs. 1-3; Fig. 5 is a vertical sectional view of a fixed fire resis¬ tive window according to the invention; and Fig. 6 is a horizontal sectional view showing one side of the fixed window illustrated in Fig. 5. Figs. 1-3 illustrate an openable multi-glass window con¬ struction which includes a wooden frame 2 and mutually connected window sashes which comprise an outer aluminium sash 4, a wooden intermediate sash 6 and a wooden inner sash " 8. The outer sash 4 comprises a framework 10 of hol¬ low profiles having an edge flange 12 and a steel L-shaped profile 14 attached to the framework 10. A single pane of Pyran glass 16 is fitted between the flange 12 and the profile 14. A sealed glazing unit 18 is inserted in a channel located at the edge surface of the inner sash 8 and the intermediate sash 6 screwed firmly thereto, the edge portions of which unit are clamped firmly in a metal¬ lic mounting frame 20 through the medium of adjustable clamping forces, the frame being screwed firmly to the inner sash in said channel. The sealed glazing unit 18 comprises a pane 22 of Pyran glass and a pane 24 of con¬ ventional window glass in spaced relationship with the pane 22. Located between the framework 10 and the inter- mediate sash 6 is a dust filter strip 26, while a spacer in the form of an inwardly open profile 28 is located between the glass panes 22 and 24. The Pyran glass pane 16 and the sealed glazing unit 18 are held clamped- with the aid of inserts 30 in the form a ceramic fibre strips. Seals in the form of hose strips 32 are provided between the inner sash and the window frame 2, and a fire-swelling strip 36 is located in a groove 34 provided in the inner sash 8. A similar fire-swelling strip 38 is also located at the outer edge of the sealed glazing unit 18. Silicone rubber top seals 40 are provided on both sides of the sea¬ led glazing unit 18. As will be seen from Fig. 3 the sash assembly comprising the inner sash 8, the intermediate sash 6 and the outer sash 4 hinged thereto is attached to the window frame 2 by means of hinge devices 42. All of the freely exposed surfaces of the intermediate sash, the inner sash and window frame are provided with a coating 44 of fire resistive paint. These coatings 44 are preferably applied to a "surface weight" of ca 500 g/m and are indicated in Fig. 3 by broken lines immediately inwards of respective surfaces of the intermediate sash 6, the inner sash 8 and the frame 2. As will best be seen from Fig. 4, the metallic clamping frame 20 (in which the sealed glazing unit 18 is pressure fitted) comprises a U-shaped profile 46 which is firmly mounted in recesses or rebates on the top rail, the bottom rail and the stiles of the inner sash 8, and an L-shaped profile 50 which has one arm or flange 48 thereof positio¬ ned within the associated U-shaped profile, such that the L-shaped profile can be pressed against the edge portion of the sealed glazing unit 18. The rebates in the afore- said rails and stiles of the sash have planar bottom sur¬ faces which extend perpendicularly to the plane of the sealed glazing unit 18, and the edge part of the unit can be clamped between one side flange 52 of the U-shaped pro¬ files and the flange 48 of the L-shaped profiles 50 exten- ding parallel therewith, by tightening clamping or pres¬ sure means 54 acting between the U-shaped and .L-shaped profiles. These clamping means may conveniently have the form of stop screws 51, which are provided with hexagonal holes and screwed through the side flange 56 of the profi- le 46 and which are tightened against the flange 48 to a given pressure, with the aid of a torque spanner. The clamping frame 20 is held firmly to the inner sash 8 by means of screws 58 which pass through the L-shaped profi¬ les 50. The edge surface of the sealed glazing unit 18 supports against an oak glazing block 60 which has a recess provided in the undersurface thereof for accommoda¬ ting the fire-swelling strip 38. As illustrated in Fig. 3, safety devices 62 are mounted on the metallic outer sash 4, within the edge region thereof at which the sash adjoins the window frame jamb in which the hinge devices 42 are fitted. The window frame jamb has provided therein retention cut-outs or recesses into which hook-shaped retention projections 66 of the safety devices 62 engage. The projection 66 and the recesses 64 thus form connection means which hold the- sashes firmly in the win- dow frame 2 when the normal sash retaining function of the hinge devices 42 has ceased. At least one such safety device 62 is provided at the top and at the bottom of the edge region of the outer sash 4, wherewith the hooked pro- jections 66 of the safety devices may conveniently be arranged to project into recesses 64 forming part of a common groove in the window frame, such as a conventional turbulence groove in the window frame. The safety devices 62 are suitably comprised of a Z-shaped extruded aluminium profile. Finally, reference is made to Figs» 5 and 6 which illu¬ strate a fixed fire resistant window which is constructed according to the same principles as the 3-pane fire resis- tant window illustrated in Figs. 1-4 and which comprises mutually connected window sashes and a 2-pane sealed glaz¬ ing unit. The glazed framework of the fixed multi-pane window con- struction includes a window frame 2' in which there is firmly fitted a glazing unit 68. Mounted in the window - frame 2' is a metallic clamping frame in which the glazing unit 68 is clamped along its edges with an adjustable clamping force generated by appropriate tightening of clamping screws 54, in the same manner as that described with reference to Fig. 4. The glazing unit 68 includes a thicker Pyrane-glass pane 22 τ and two panes 24' of conven¬ tional window glass located in spaced relationship with the pane 22' and inwardly thereof. Arranged between the edge regions of the respective panes of glass in the glazr- ing unit 68 are metal profiles 70 which serve as spacing and holding elements and against the mutually opposing sides surfaces of which respective panes are glued at regions 72 with the aid of a silicone adhesive. Those parts of the clamping frame 20' which are located inwardly of the glazing unit 68 on the inward side of the construction are covered with wooden glazing strips or rails 74, 76 attached to the window frame. The freely ex- posed surfaces of the wooden window frame 2' and glazing strips 74, 76 on the inward side of the window construc¬ tion are coated with a layer 44' of fire resistive paint. The remaining elements and components of the Fig. 5 and 6 embodiment are the same as mutually corresponding elements and components of the embodiment illustrated in Figs. 1-4 and have accordingly been identified by the same reference numerals. As will be evident from the aforegoing, the reference numerals in certain instances have added thereto a prime, so as to indicate a construction which although slightly different is nevertheless the same in principle. It is mentioned in conclusion that the invention is not limited to the aforedescribed and illustrated embodiments thereof and that the invention embraces all embodiments and equivalent solutions which lie within the scope of the following claims.

Claims: CLAIMS 1. An openable multi-pane window construction, particular¬ ly a multi-pane window construction of fire resistance class F 60, the glazed framework of which construction includes a window frame (2) and mutually connected window ' 5 sashes (4, 6, 8), and in which window construction a sing¬ le pane (16) of glass is fitted in an outer sash (4) loca¬ ted on the outward side of the construction and an inner glazing unit (18) comprising at least one pane of glass is fitted in an inner sash (8) located on the inward side of 10 the construction, characterized in that; the window frame (2) and the inner sash (8) are made of wood, wherewith the inner sash has mounted therein a metallic clamping frame (20) in which the inner sealed glazing unit (18) is clamped firmly along the edges there- 5 of through the action of an adjustable clamping force; both the single pane (16) and a glass pane (22) incorpora¬ ted in the inner sealed glazing unit are made of plain heat hardened borosilicate-fire resistive glass, such as Pyran glass R; 0 the outer sash (4) is a metal frame spaced outwardly of the wooden inner sash; and at least the freely exposed surfaces of the wooden window frame (2) and the wooden inner sash (8) located on the inside of the construction are provided with a coating 5 (44) of fire resistive paint. 2. A window construction according to Claim 1, characteri¬ zed in that the glazing unit on the inward side of the construction comprises a sealed glazing unit (insulating 0 glass unit 18) which incorporates in addition to the pane (22) of borosilicate-fire resistant glass a pane (24) of conventional window glass which is located on the inward side of the unit and in spaced relationship with the fire- resistive pane (22). 3. A window construction according to Claim 1, characteri¬ zed in that the glazing unit on the inward side of the construction comprises a- single pane (22) of plain, heat hardened borosilicate-fire resistive glass, which is lami¬ nated, e.g., with a low emissive glass sheet. 4. A window construction according to any of Claims 1-3, characterized in that in the vicinity of the interspace between the inner sash (8) and the window frame (2) there is inserted in at least one of said two components a fire- swelling strip (36) extending peripherally around the whole of the inner sash. 5. A window construction according to any of the preceding claims, characterized in that the metallic clamping frame (20) in which the inwardly located glazing unit (18) is clamped includes U-shaped profiles (46) which are fitted in cut-outs or recesses in the top rail, the bottom rail and the stiles of the inner sash (8), these cut-outs or recesses having planar bottom surfaces which extend per- pendicularly to the plane of the inner glazing unit, and an L-shaped profile (50) one arm of flange (48) of which is located within the confines of an associated U-shaped profile and can be pressed against an edge part of the glazing unit (18), wherewith the edge part of said unit can be clamped between one side flange (52) of the U-sha¬ ped profile and the flange (48) of the L-shaped profile extending parallel with said side flange, by tightening clamping devices (54) acting between the U-shaped and L-shaped profiles. 6. A window construction according to Claim 5, characteri¬ zed in that the edge part of the inner glazing unit (iδ) is clamped between the mutually co-acting and mutually parallel flanges (52, 48) of the U-shaped and L-shaped 5 profiles (46, 50) with elastic inserts (30) preferably of ceramic fibre strips and in that the sealing silicone top seals (40) are provided at the free edge surfaces of the inserts on both sides of the unit. 10 7. A window construction according to any of Claims 1-6, characterized in that a wooden intermediate sash (6) is arranged between the inward sash (8), in which the metal¬ lic clamping frame (20) for the inner glazing unit (18) is secured, and the outer sash (4), the intermediate sash (6 15 forming spacer means between the inne sash and the outer sash for the single glass pane and being provided with a coating (44) of fire resistive paint on the freely exposed surface regions thereof. 20 8. A window construction according to one or more of Claims 1-7, in which the mutually connected sashes are pivotally hung and are held in the window frame (2) by means of hinges (42) located between the window frame and the inner sash, characterized in that safety devices (62) ?5 provided with hook-shaped retaining projections (66) are mounted against the metallic outer sash (4) within the edge region thereof which is contiguous with the frame jamb to which the hinges (42) are fitted; and in that said frame Jamb has provided therein retention recesses (64) 30 for receiving said projections (66), the projections (66) and the recesses forming connections which hold the sashes firmly in the window frame when the normal sash retaining function of the hinges cease. 35 9. A window construction according to one of more of Claims 5-8, characterized in that in comparison with known wooden inner sashes, the inner sash of the construction has larger material dimensions at least with regard first¬ ly to the material thickness measured from the rebate side of the attachment rebate of the clamping frame (20) and inwardly to the inside surface (78) of the inner sash extending parallel with the glazing unit, and secondly to the material thickness measured from the rebate bottom surface out to the defining surface (80) of the inner sash parallel with said bottom surface, wherewith the two thicknesses are at least 20 mm and preferably ca 22 mm. 10. A window construction according to Claim 8 or 9, cha¬ racterized in that a safety device (62) is provided in the top edge region and in the bottom edge region of the metallic outer sash (4), wherewith the hooked projections (66) of said two safety devices project into a common groove or channel (64) provided in the window frame, such as a conventional turbulence groove in said frame (2). 11. A fixed multi-pane window construction, particularly a multi-pane window of fire resistance class F 60, the gla¬ zed framework of which construction, includes a window frame (2') in which there is fitted a glazing unit (68), characterized in that; the window frame (2'), which is made of wood, has mounted therein a metallic clamping frame (20') in which the glaz¬ ing unit (68) is clamped along its edges by an adjustable clamping force; the glazing unit (68) includes at least one pane (22') of plain, heat hardened, borosilicate-fire resistive glass, such as Pyran glass , and at least one, preferably two, pane(s) (24') of conventional glass fitted inwardly of the borosilicate-fire resistive pane and spaced therefrom, wherewith metallic profiles (70) are provided between the edge regions of the glass panes in the glazing unit, these profiles functioning as spacer elements and respective glass panes being bonded-to mutually opposite side surfa¬ ces of said profiles (70) with the aid of a silicone adhesive; those parts of the metallic clamping frame (20') which are located inwardly of the inside of the unit (68), on the inward side of the construction, are covered with wooden glazing strips (74, 76) attached to the window frame; and at least the freely exposed surfaces of the wooden window • frame and the glazing strips are provided with a coating (44') of fire resistive paint.

Inventors: BROWALL ANDERS, BROWALL, ANDERS
Applicants: ELIT FOENSTER AB, ETRI FOENSTER AB
Application year: 1987
Main classification: E06B5
IPC codes: E06B3, E06B5