GB1603430A

GB1603430A - Window or door frame member

Info

Publication number: GB1603430A
Application number: GB4721077A
Authority: GB
Original assignee: BKL Extrusions Ltd
Current assignee: BKL Extrusions Ltd
Priority date: 1977-11-12
Filing date: 1977-11-12
Publication date: 1981-11-25
Also published as: IE782214L; IE48054B1

Description

(54) WINDOW OR DOOR FRAME MEMBER (71) We, BKL EXTRUSIONS LIMITED, a British Company, of Factory Centre, Kings Norton, Birmingham B30 3HF, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement :- This invention relates to frames for windows or doors.

One problem which can arise with metal framed windows is that of condensation occurring on the metal frame. This is because, in the case of a great temperature difference existing between opposite sides of the window, considerable heat flow can occur through the metal frame. Further, in cold weather this can lead to appreciable undesirable heat loss from a room or building, in addition to the condensation probelm. These effects are aggravated by the fact that metal window frames are commonly made of metals such as aluminium or its alloy, having a relatively high thermal conductivity. It is an object of the present invention to overcome or reduce these advantages.

According to one aspect of the present invention, we provide a frame member for a window or door, such frame member incorporating a metal member with a portion which is presented at a position which would otherwise be externally accessible when the frame member is installed as part of a window or door structure but which is provided with a covering of a thermally insulating material to restrict heat transfer between the frame and external atmosphere, said covering comprising an extruded member of a plastics material, having longitudinally extending formations which engage with cooperating formations on the metal member mechanically to secure the plastics member to the metal member, which formations include a groove in said plastics member and a projection on said metal member which, in cross section, is barbed and which is received in said groove to secure the plastics member to the metal member.

The thermally insulating material may be a foamed plastics material, and may be extruded by a process which provides it with a hard solid skin whilst providing a foamed core to the extrusion.

The covering of thermally insulating material may define an air space between itself and the portion of the frame member which it covers, further to assist its insulating effect.

The covering of thermally insulating material may be provided with a sealing formation adapted to engage a frame member or other part of a further window assembly, to provide for sealing between two relatively movable frame members. In the case of a plastics extrusion, the sealing formation may form part of said extrusion but be of a more resilient material than the remainder of the extrusion.

The frame member may receive a glazing strip by way of cooperating formations on the frame member and glazing strip, the glazing strip serving to secure a glazing panel to the frame member in a manner such that the glazing panel contacts and seats against the glazing strip rather than the frame member.

The frame member may be intended to be an inner or outer window or door frame member, or a mullion or transome member, and various forms of such member are described hereafter. The frame member is preferably in the form of an extrusion of aluminium or an alloy thereof.

The invention will now be described by way of example with reference to the accompanying drawings, of which :- FIGURE 1 is a section showing part of a structure incorporating fixed and movable window frame members incorporating a thermally insulating covering not in accordance with the present invention but illustrating certain features which the invention may include.

FIGURE 2 is a section showing a mullion or transome member and a movable frame member similar to Fig. 1.

FIGURE 3 is a section showing an embodiment of the invention.

Referring firstly to figure I, the structure there shown comprises an outer frame member 10 secured by means not shown to a structure I1 surrounding the window aperture, and an inner frame member 12 which carries a glazing panel 13. The window is openable by movement of the inner frame member 12 away from the outer frame member in the direction of arrow 14.

The outer frame member 10 is extruded from aluminium or an alloy thereof, and has a cross sectional shape presenting, having regard to the orientation shown in figure 1, a horizontally extending web 15 forming part of the boundary of an undercut groove 16, and front and rear vertically extending flanges 17, 18 respectively. At its lower edge, the flange 17 is slightly thickened to form a bead 19, and at its upper end is provided with an L-shaped projection 20. The flange 18 is formed at its upper edge with projections defining an undercut groove 21.

The groove 21 receives a flexible sealing strip 22, for sealingly engaging the inner frame member 12. The bead 19 and projection 20 on the flange 17 of the outer frame member together provide for securement of a plastics extrusion 23 to the outer frame member, the extrusion 23 having a cross sectional shape affording inturned lips which engage with the bead 19 and projection 20, a foot 24 which serves to maintain the plastics extrusion in spaced relation with the flange 17, and a sealing formation 25 which sealin- gly engages the periphery 1 I of the window.

The extrusion 23 is formed of a relatively rigid plastics material, except for the formation 25 which is of a more flexible material.

The inner frame member 12 has a cross sectional shape affording a web 26 and front and rear flanges 27,28. The flange 28 has a forwardly extending projection 29 which receives a glazing wedge gasket 30, and a downwardly extending projection 31 with which the sealing strip 22 engages. The flange 27 of the inner frame member is of the same shape as the flange 17 of the outer frame member, and receives a plastics extruded cover 32 identical to that which is fitted on the outer frame member. The sealing formation of the plastics extrusion 32 engages the front face of the plastics extrusion fitted to the outer frame member, when the window is closed.

The inner frame member 12 also receives an extruded plastics glazing bead 33, the glazing bead being secured to the frame member by having portions received in grooves 34,35. The glazing bead 33 has an inturned portion 36 which contacts the glazing panel 13 to hold the latter against the glazing wedge gasket the edge of the glazing panel being adjacent the part of the glazing bead 33 which extends across the web 26 of the frame member.

Referring now to figure 2, there is illustrated a structure which includes an inner frame member and glazing panel, indicated generally at 50, which is identical to the inner frame member and associated components of figure) and will not therefore be described in further detail. The inner frame member fits against a transome or mullion assembly 51, which comprises an extruded aluminium transome or mullion member with a plastics covering member.

The transome or mullion member comprises a box section 52 with flanges 53, 54 extending in opposite directions from its rear side and forwardly extending legs 55,56. The flanges 53,54 terminate in undercut grooves as shown at 57 for the flange 54, for receiving a glazing wedge 58 when a glazing panel 59 is required to fit directly against the transome or mu ! lion. In this case, a glazing bead 60 identical to the glazing bead 33 described with reference to figure 1 is used to retain the glazing panel in position against the transome or mullion.

At the front of the mullion or transome member, an extruded cover (61) is secured by inwardly extending resilient legs 62 terminating in beads which engage behind projections on the legs 55,56.

It will be noted with reference to the constructions shown in figures I and 2 that no part of the extruded aluminium frame members is exposed at the exterior to external atmospheric conditions. The extruded plastics coverings act as thermal insulation to limit heat transfer to or from the metal frame members.

The thermally insulating covering need not define an air space between itself and the frame member, although its insulating effect is enhanced if such a space does exist.

The present invention provides an improved means of fastening the covering of thermally insulating plastics material to a metal member, and this is described with reference to Figure 3.

Referring now to Figure 3 of the drawings, there is illustrated a window frame assembly occupying an aperture defined by a building structure 100. The window assembly comprises a fixed frame assembly 101 fixed to the building structure and incorporating a mullion or transome member 102, and a moveable frame assembly 103.

The fixed frame assembly 101 comprises a main extruded aluminium frame member which in cross section presents front and rear end flange portions 104,105 and an interconnecting web portion 106. The rear flange portion has a forward facing projection 107, projections 108 which face the rear of the section, a barbed projection 109, and a lip 110 at its one free end. The front flange portion has a lip 111, and the web 106 is of cranked shape having a projection 112 which faces the projection 107 to define an undercut groove 113.

The frame member 101 is secured to the building structure surrounding the window aperture by a plurality of spaced lug members 114. Each lug member is secured to the building structure by a fastener 115, and to the frame member by the engagement of a resilient generally T shaped portion 116 of the lug within undercut groove 113. The free end of the opposite limbs of the T shape abut the projections 107,112, while the central portion of the T shape abuts web 106, the material (aluminium) of the lug member being resiliently deformed to fit within groove 113 so that the frame member 101 is securely attached to the building structure.

A mastic seal 117 is provided between the projection 111 of the front flange portion 104 and the building structure, and a plastics trim strip 118 is fitted at the rear of the frame member, having resilient legs which engage with a lip 1 19 at the free end of each lug 114 and with a thermally insulating member to be described hereafter.

The thermally insulating member, 120, is made of a foamed, hard skinned, plastics material formed by extrusion, in its cross sectional shape presenting a groove within which the lip 110 and one of the projections 108 fit, a further groove in which the other projection 108 fits, and a relatively narrow groove in which the barbed projection 109 is received to secure the thermally insulating member to the frame member. The thermally insulating member may be of the type of plastics extrusion known as"Celuka" (registered trade mark) and may be of any appropriately selected thermo-plastics material to present the desired qualities of thermal insulation and resistance to weathering. The thermally insulating effect is assisted by the fact that such a type of extrusion has a foamed interior, although the exterior of the extrusion is unfoamed and rigid.

By virtue of the provision of the thermally insulating member 120 thereon, no metallic part of the outer frame member 101 is accessible at the interior of the building structure. Thus, disadvantages of heat loss and condensation referred to above are overcome.

The moveable frame assembly 103 is formed of an extruded frame member 121 which, as in the case of the fixed frame member, comprises a web and front and rear flange portions. The rear flange portion 122 thereof corresponds in shape to the rear flange portion 105, and receives a thermally insulating member 123 identical to the thermally insulating member 120. The front flange portion, 124, of the moveable frame member has a part which extends generally rearwardly to receive a flexible weather seal 125, and also provides for attachment of a glazing bead 126 by means of which a double glazing panel 127 is secured in position.

The mullion or transome member 102 is of somewhat rectangular hollow form in cross section, and at its rear (i. e. towards the interior of the building structure) is provided with two oppositely directed flange formations 128, 129, which as viewed in section are mirror images of one another's shapes, identical to the rear flange portion 105 on which thermally insulating member 120 fits. Thus, the flanges 128,129 carry thermally insulating members 130, 131, these members being identical to member 120. A thermally insulating filler strip 132 fits between members 130and 131.

Thus, all parts of the mullion or transome 102 which are accessible from within the building structure are covered by thermally insulating members. The window assembly as a whole thus presents the thermal insulating properties as described above in relation to the assembly of Figures I and 2.

In the embodiments above described, the thermally insulating covering members are fitted on one side only of the metal frame members, either towards the interior or the exterior of the building structure. However, if desired a thermally insulating covering member may be provided on both sides of the metal frame members to provide enhanced thermal insulation and, if desired, a decorative finish.

Claims

WHAT WE CLAIM IS : 1. A frame member for a window or door, such frame member incorporating a metal member with a portion which is presented at a position which would otherwise be externally accessible when the frame member is installe as part of a window or door structure but which is provided with a covering of a thermally insulating material to restrict heat transfer between the frame member and external atmosphere, said covering comprising an extruded member of a plastics material, having longitudinally extending formations which engage with cooperating formations on the metal member mechanically to secure the plastics member to the metal member, which formations include a groove in said plastics member and a projection on said metal member which, in cross section, is barbed and which is received in said groove to secure the plastics member to the metal member.
2. A frame member according to claim 1, comprising, in cross section, spaced flange portions connected by a web portion, and wherein said covering of thermally insulating material is provided on one of said flange portions.
3. A frame member according to claim I or claim 2 wherein said plastics member is of a foamed plastics material, extruded by a process which provides it with a hard solid skin whilst providing a foamed core to the extrusion.
4. A frame member according to any one of claims I to 3 wherein said plastics member is provided with a sealing formation adapted to provide for sealing between the frame member and another, relatively movable, member.
5. A frame member according to claim 4 wherein said sealing formation is of a more resilient plastics material than the remainder of the plastics member.
6. A frame member according to any one of claims I to 5 wherein an air space is defined between the plastics member and metal member.
7. A window assembly incorporating a frame made from frame members according to any one of claims I to 6 and a glazing panel, said glazing panel abutting said plastics member and not the metal member.
8. A window assembly according to claim 7 and further incorporating a transome or mullion member, said transome or mullion member also bearing a covering thermally insulating plastics member.
9. A window assembly according to claim 8, wherein said transome or mullion member is of a cross sectional shape affording two flange portions each of the same shape as the flange portion of said frame members and provided with one of said plastics members.
10. A frame member substantially as hereinbefore described with reference to and as shown in Figure 3 of the accompanying drawings.
11. A window assembly substantially as hereinbefore described with reference to and as shown in Figure 3 of the accompanying drawings.