Manufacture of thermally insulated frame members

Abstract

 A thermally insulated frame member 35 for a door or indow comprises two elongate metal components 36, 37 terconnected only bythermally insulating plastics material. he two metal components are initially interconnected by two reformed elongate plastics components 38 each of which rms a mechanical interlock with each of the metal compo- ents and defines there with a channel. The two channels face directly opposite directions to each other and are filled in im with a settable thermally-insulating plastics material 39 a fluid condition, the material in one channel being allowed set before the member is inverted and the other channel is led. Each ofthe bodies of plastics material 39 thus moulded rming a mechanical interlock with each of the metal comments 36, 37.

Description

[0001] This invention relates to the manufacture of thermally insulated frame members, for example for doors and windows.

[0002] According to this invention there is provided a method of making an elongate frame member comprising two elongate metal components interconnected only by thermally insulating plastics material, which method comprises interconnecting the two components by means of one or more preformed third components made from a flexible resilient thermally insulating plastics material extending along the length of the member, which third component or components are snap-fitted into engagement with each of said two components the three components being adapted so that the third component or each of the third components forms a mechanical interlock with each of said metal components and defines jointly with the two metal components an open channel, then filling the channels with a curable thermally insulating plastics material in a fluid condition, the part of the or each channel defined by each of the said two metal components being shaped to form a mechanical interlock between that component and the cured plastics material.

[0003] Preferably the two metal components are interconnected by two of said third components to form two said channels, which face in opposite directions to each other, and one of the channels is filled and the material allowed to cure and then the member is inverted and the other channel is filled and the material allowed to cure.

[0004] In one arrangement according to the invention, one of said two components has projecting towards the other component a leg extending lengthwise of the component and having in cross-section portions extending at an angle to one another, the third component providing a slot which accommodates a part of the leg extending from the free end thereof beyond the angle and is such that the third component can be snapped over said leg, and the other component defines a channel which is shaped to accommodate the third component and into which the third component, with said part of the leg of said one component engaged therein, is snap fitted.

[0005] In a preferred method according to the invention, each of said two metal components has three lengthwise extending ribs which are generally parallel to each other and which respectively project towards but stop short of corresponding ribs on the other of said metal components, and the third component or each of them is of generally H-section and has its two limbs at one side of the cross-bar thereof accommodating between them in a snap fit an end one of the three ribs on one of said metal components, the middle one of the three ribs engaging one of said two limbs such that said one limb is accommodated between said end and middle ribs, said middle rib and the other end rib being so shaped and/or disposed that a secondary channel which is defined between them and which constitutes a lateral branch of the first or main channel forms said mechanical interlock of that component with the cured plastics material, and the two limbs at the other side of said cross-bar being correspondingly engaged in a snap fit with the three ribs on the other of said metal components.

[0006] Two embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figures 1 to 4 respectively show successive steps in a method according to the invention of making a thermally insulated frame member,

Figure 5 shows a second form of thermally insulated frame member made by a method according to the invention, and

Figure 6 shows one of the components of Figure 5 on an enlarged scale.

[0007] Referring to Figure 1, the two metal components are aluminium extrusions and are shown at 10 and 11 respectively. Component 10 has on its rear surface two formations each comprising a projecting flange 13 having a divergent head portion 14, and just short of the portion 14 a lateral limb 15 with a leg 16 and a foot 17 of which extends at right angles to the leg. In the first stage of the method two preformed (extruded) thermally insulating plastics members 20 are engaged with the foot 17 and adjacent portion of the leg 16 of the two formations respectively. For this purpose each member 20 is formed with a slot 21 and is sufficiently flexible and resilient to enable the foot of the formation to be snapped into position in the slot as shown. -There is thus a mechanical interlock between the leg and foot and the associated member 20.

[0008] The other metal component 11 has two formations each comprising a lengthwise plain rib 24, a rib 25 of divergent cross-section forming with rib 24 a dovetail groove 26, and a projecting flange.27 having a chamfered lip 28 at its extremity. In the second step, the flanges 27 are pressed into engagement with the plastics extrusions, and are deflected laterally allowing the extrusions to snap into place between the rib 24 and flange 27 of the respective formations as shown in Figure 2. A mechanical interlock is thus formed between each of the plastics extrusions 20 and the component 11.

[0009] The plastics extrusions 20 now respectively define jointly with the components 10 and 11 two open channels 30 which face laterally away from each other, and in the first two steps of the method illustrated in Figures 3 and 4 respectively these channels are filled with a curable thermally insulating plastics material 31-in a fluid condition. It will be seen that the dovetail groove 26 in member 11 and a similar dovetail groove 32 formed between the leg 15 and the head portion 14 of flange 13 form mechanical interlocks between the two components and the plastics material in the channels.

[0010] The two components 10, 11 are thus mechanically connected together only through thermally insulating plastics material.

[0011] Referring now to Figures 5 and 6 of the drawings, the frame member 35 is constructed from two extruded aluminium components 36, 37 joined together by two preformed (extruded) components 38 made from a thermally insulating plastics material and two bodies 39 of cured thermally insulating plastics material moulded in situ.

[0012] Component 36 has on its rear face two sets of three ribs 40, 41, 42 which extend lengthwise of the component and which project in directions substantially parallel to each other towards co-operating sets of three ribs 43, 44, 45 at the rear side of component 37. Ribs 43, 44, 45 are mirror images of ribs 40, 41, 42 respectively but are formed at the rear or inner ends of flanges 46 on component 37.

[0013] The plastics components 38 are of substantially H-section and their two limbs 47, 48 at one side of the cross-bar 49 accommodate between them an end 42 of the ribs in a snap fit due to the provision of interengaging wedge-shaped formations adjacent the free ends of the mutually engaging faces of limb 47 and rib 42. Limb 47 can deflect resiliently to enter into engagement with rib 42. Ribs 41 and 42 are in face-to-face engagement with opposite sides of limb 48 of component 38 and the tip of the rib 41 abuts a shoulder 50 on component 38. The limbs 52, 51 at the other side of cross-bar 49 are similarly engaged with ribs 44, 45. The wedge-shaped formations on limbs 47 and 51 co-operate with those on ribs 42 and 45 to hold ribs 41, 44 against shoulder 50 which serve to space the components 36, 37 a selected distance apart. A mechanical interlock is thus formed between components 38 and each of the components 36, 37.

[0014] To form the complete frame member 35, the two components 36 and 37 are clippsed together by the two extruded plastics components 38, so that the components together define two outwardly facing channels. The assembly is disposed with one of the channels facing upwardly and the channel is then filled with a settable thermally insulating plastics material in a fluid condition. After the material has set, the assembly is turned the other way up and the other channel is filled with a settable plastics material. The ribs 40, 43 each have an inclined side wall as shown which forms in conjunction with the adjacent rib 41 or 44 a secondary channel 51 which forms a lateral branch of the main channel and which reduces in width towards the main channel so as to form a mechanical interlock with the plastics material 39 which is moulded in the channel. The two aluminium components 36, 37 are thus interconnected only through the heat insulating plastics components 38 and moulded bodies 39.

[0015] The plastics interconnecting component 38, whilst correctly locating the two aluminium components 36, 37 relative to each other during the forming and filling of the main channel and the curing of the resin 39 has served its purpose when said resin has fully cured and makes no significant addition to the weight or strength of the final section.

Claims

1. A method of making an elongate frame member comprising two elongate metal components interconnected only by thermally insulating plastics material, which method comprises interconnecting the two components by means of one or more pre.- formed third components made from a flexible resilient thermally insulating plastics material extending along the length of the member, which third component or components are snap-fitted into engagement with each of said two components the three components being adapted so that the third component or each of the third components forms a mechanical interlock with each of said metal components and defines jointly with the two metal components an open channel, then filling the channels with a curable thermally insulating plastics material in a fluid condition, the part of the or each channel defined by each of the said two metal components being shaped to form a mechanical interlock between the component and the cured plastics material.

2. A method as claimed in claim 1, wherein one of said two components has projecting towards the other component a leg extending lengthwise of the component and having in cross-section portions extending at an angle to one another, the third component providing a slot which accommodates a part of the leg extending from the free end thereof beyond the angle and is such that the third component can be snapped over said leg, and the other component defines a channel which is shaped to accommodate the third component and into which the third component, with said part of the leg of said one component engaged therein, is snap fitted.

3. A method as claimed in claim 1, wherein each of said two metal components has three lengthwise extending ribs which are generally parallel to each other and which respectively project towards but stop short of corresponding ribs on the other of said metal components, and the third component or each of them is of generally H-section and has its two limbs at one side of the cross-bar thereof accommodating between them in a snap fit an end of one of the three ribs on one of said metal components, the middle one of the three ribs engaging one of said two limbs such that said one limb is accommodated between said end and middle ribs, said middle rib and the other end rib being so shaped and/or disposed that a secondary channel which is defined between them and which constitutes a lateral branch of the first or main channel form said mechanical interlock of that component with the cured plastics material, and the two limbs at the other side of said cross-bar being correspondingly engaged in a snap fit with the three ribs on the other of said metal components.

4. A method as claimed in any one of claims 1 to 3, wherein the two metal components are interconnected by two of said third components to form two said channels, which face in opposite directions to each other, and wherein one of the channels is filled and the material allowed to cure and then the member is inverted and the other channel is filled and the material allowed to cure.

5. An elongate frame member assembly comprising two elongate metal components interconnected by one or more third components preformed from a flexible resilient thermally insulating plastics material extending along the frame member, the three components being adapted so that the third component or each of the third components forms a mechanical interlock with, and is a snap fit with, each of said metal components and defines jointly with the two metal components an open channel, the part of the or each channel defined by each of the said two metal components being shaped to form a mechanical interlock between the component and a substance subsequently to be placed in the channel.

6. An assembly as claimed in claim 5, wherein two of said channels are provided and face in opposite directions to each other.

Drawing