| CLAIMS A frame for an opening in the wall of a building comprising at least three structural components press formed in sequence from a single sheet of metal to a corresponding channel profile having a pair of lipped flanges, with the ends of contiguous components configured to meet as corner joints and the lips of the flanges extending to connect the components at the joints. A frame as claimed in claim 1 in which the ends of the flanges are inclined to meet at the joints between the contiguous components and one of the contiguous ends of the flanges at a joint having an offset lug extending therefrom which locates on the inside of the other contiguous flange and provides a shoulder to abut the lip on the other flange. A frame as claimed in claim 1 or claim 2 in which the components include bendable tongue formations at their ends locatable through slots in contiguous components at the joints. A frame as claimed in claim 3 in which the tongue formations are provided as extensions on the lugs adjacent the shoulders. A frame as claimed in any one of claims 1 to 4 in which the components have a channel web with an end which abuts an overlapping web on a contiguous component at a joint. 6. A frame as claimed in claim 5 in which tongue formations are provided on the channel web and stepped to the inside of the channel to be offset from the component. 7. A frame as claimed in any of claims 1 to 6 in which the channel profile includes a return along the free edges of the lips. 8. A frame as claimed in claim 7 in which the returns are notched between contiguous components. 9. A door frame comprising two opposite side jambs and a header formed in sequence from a single sheet of metal to a corresponding channel profile having a pair of lipped flanges, the ends of the flanges configured to meet as joints between the jambs and header, one of the contiguous ends of the flanges at a joint having an offset lug extending therefrom which locates on the inside of the other contiguous flange and provides a shoulder to abut the lip on the other flange, and means to connect the header to the jambs at each of the two joints. 1 0. A frame as claimed in claim 9 in which the connecting means is provided by a common, overlapping lip on the flanges with an indent providing a fold line between the header and jambs. 1 1 . A frame as claimed in claim 9 in which the connecting means are bendable tongue formations locatable through slots at the joints. 1 2. A frame as claimed in claim 1 1 in which the tongue formations are provided as extensions on the lugs adjacent the shoulders. 1 3. A frame as claimed in any one of claims 9 to 12 in which the jambs have a channel web with an end which abuts an overlapping web of the header at the two joints. 14. A frame as claimed in claim 13 in which the end of the abutting web has at least one tongue formation stepped to the inside of the channel to be offset from the component and locatable through a slot in the overlapping web of the header. 15. A frame as claimed in any of claims 9 to 14 in which the channel profile includes a return along the free edges of the lips. 1 6. A set of door frame components comprising a header with a pair of jambs as claimed in claim 9. 1 7. A window frame comprising four structural components formed in sequence from a single sheet of metal to a channel profile having a pair of lipped flanges, the ends of the components configured to meet as four joints to form a rectangular frame structure, with the lips of the flanges extending to connect the components at three of the joints. 18. A frame as claimed in claim 17 in which the lips of the flanges have an indent providing a fold line where they connect the components. 19. A frame as claimed in claim 17 or claim 1 8 in which the end of one contiguous component has a channel web which abuts an overlapping web of the other contiguous component at a joint. 20. A frame as claimed in claim 19 in which the end of the abutting web has at least one bendable tongue formation stepped to the inside of the channel to be offset from the component and locatable through a slot in the overlapping web. 21 . A frame as claimed in any one of claims 17 to 20 in which one of the contiguous ends of the flanges at a joint has an offset lug extending therefrom which locates inside the other contiguous flange and provides a shoulder to abut the lip on the other flange. 22. A frame as claimed in any of claims 17 to 21 in which tongue formations are provided as extensions on the lugs adjacent the shoulders, with corresponding slots in the lip of the contiguous flange. 23. A frame as claimed in any of claims 17 to 22 in which the channel profile includes a return along the free edges of the lips. 24. A blank for a frame as claimed in any of claims 1 to 15 or 17 to 24. |
FIELD OF THE INVENTION
The invention relates to a door frame and/or a window frame and, in particular, to such frames made from sheet metal.
BACKGROUND TO THE INVENTION
There are a number of different door frames available for use in buildings. Similar door frames often have different constructions and methods of assembly. Door frames of the kind to which the invention relates are usually assembled by welding. The welding is then ground down and the frame painted. It is also known to have separate connecting components for such frames, which are usually moulded from plastics material and used to connect a door frame header onto the two jambs. Welding is conventionally important to reinforce the door frame structure, particularly where it will bear a load, which is usually the case with brick buildings. A jig will often be used to hold the components at 90 degrees while they are being welded at the frame joints. Window frames are also available in a number of different configurations. Those of the kind to which the invention relates are often used in construction of low cost housing. A practical window frame of reliable strength which is easy to manufacture is desirable in many building applications.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a door/window frame that is simple to manufacture and which provides a reasonable degree of strength.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a frame for an opening in the wall of a building comprising at least three structural components press formed in sequence from a single sheet of metal to a corresponding channel profile having a pair of lipped flanges, with the ends of contiguous components configured to meet as corner joints and the lips of the flanges extending to connect the components at the joints.
The invention further provides for the ends of the flanges to be inclined to meet at the joints between the contiguous components and for one of the contiguous ends of the flanges at a joint to have an offset lug extending therefrom which locates on the inside of the other contiguous flange and provides a shoulder to abut the lip on the other flange.
Further features of the invention provide for the components to include bendable tongue formations at their ends locatable through slots in contiguous components at the joints; and for the tongue formations to be provided as extensions on the lugs adjacent the shoulders.
Further features of the invention provide for the components to have a channel web with an end which abuts an overlapping web on a contiguous component at a joint; and for the tongue formations to be provided on the channel web and stepped to the inside of the channel to be offset from the component.
Further features of the invention provide for the channel profile to include a return along the free edges of the lips; and for the returns to be notched between contiguous components.
In accordance with another aspect of the invention there is provided a door frame comprising two opposite side jambs and a header formed in sequence from a single sheet of metal to a corresponding channel profile having a pair of lipped flanges, the ends of the flanges configured to meet as joints between the jambs and header, one of the contiguous ends of the flanges at a joint having an offset lug extending therefrom which locates on the inside of the other contiguous flange and provides a shoulder to abut the lip on the other flange, and means to connect the header to the jambs at each of the two joints.
This aspect of the invention further provides for the connecting means to be provided by a common, overlapping lip on the flanges with an indent providing a fold line between the header and jambs; and/or for the connecting means to be bendable tongue formations locatable through slots at the joints.
Further features of the invention provide for the tongue formations to be provided as extensions on the lugs adjacent the shoulders; for the jambs to have a channel web with an end which abuts an overlapping web of the header at the two joints; and for the end of the abutting web to have at least one tongue formation stepped to the inside of the channel to be offset from the component and locatable through a slot in the overlapping web of the header; and for the channel profile to include a return along the free edges of the lips. A further aspect of the invention provides a set of door frame components comprising a header with a pair of jambs as defined. Another aspect of the invention provides a window frame comprising four structural components formed in sequence from a single sheet of metal to a channel profile having a pair of lipped flanges, the ends of the components configured to meet as four joints to form a rectangular frame structure, with the lips of the flanges extending to connect the components at three of the joints.
This aspect of the invention further provides for the lips of the flanges to have an indent providing a fold line where they connect the components. Further features of the invention provide for the end of one contiguous component to have a channel web which abuts an overlapping web of the other contiguous component at a joint; for the end of the abutting web to have at least one bendable tongue formation stepped to the inside of the channel to be offset from the component and locatable through a slot in the overlapping web.
Further features of the invention provide for one of the contiguous ends of the flanges at a joint to have an offset lug extending therefrom which locates inside the other contiguous flange and provides a shoulder to abut the lip on the other flange; for tongue formations to be provided as extensions on the lugs adjacent the shoulders, with corresponding slots in the lip of the contiguous flange; and for the channel profile to include a return along the free edges of the lips.
Yet another aspect of the invention provides a blank for a frame as defined. BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a plan view of cut and pressed jamb and header components for a door frame; Figure 2 shows a perspective view of the components after they have been rolled to form;
Figure 3 shows a schematic end view of the rolled profile;
Figure 4 shows a joint between two components once the door frame has been assembled;
Figure 5 shows a plan view of the joint in Figure 4;
Figure 6 shows a plan view of cut and pressed components for a window frame;
Figure 7 shows an enlarged view of the formations at a joint between components of the window frame in Figure 6;
Figure 8 shows a perspective view of the adjacent ends of two components after they have been rolled to form;
Figure 9 shows a schematic end view of the rolled profile;
Figure 10 shows a joint between components once the window frame has been assembled; and
Figure 1 1 shows a plan view of the joint in Figure 10.
DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, a door frame (1 ) is made primarily of three components; these are two opposite side jambs (2) and a header (3). The jambs (2) are in use connected to the header (3) which extends across the top of the jambs (2). The header (3) with a jamb (2) extending to each side is initially cut from sheet metal. This will normally be mild steel. The sheet is provided with the required width and length.
A punch is then used in a pressing operation to cut out a piece of the sheet metal between the header (3) and two jambs (2), at (4). This provides the adjacent ends of the components with formations which will be used to connect the header (3) and jambs (2) in a 90 degree joint as required to form the assembled door frame. The components (2) and (3) at this stage of manufacture form part of a blank (1 A) for a door frame as illustrated in Figure 1 . After the components (2) and (3) have been cut and pressed, a rolling process is used to provide them with a channel profile. This is indicated by (1 B) in Figures 2 and 3.
The channel has a web with two lipped flanges. The portions of the pressed components which make up the web, flanges and lips are indicated by (a), (b) and (c) respectively. A return, indicated by (d), is provided along the length of the lip (c). The return (d) extends back parallel to the channel flange (b).
In this embodiment the web (a) will be rolled to have a single rebate adjacent one of the flanges (b). It will be appreciated that the frame (1 ) can alternatively be provided with a double rebate (i.e. one adjacent each of the flanges) or with some other cross-sectional profile.
The ends (6) of the flanges (b) are provided with an edge inclined at 45 degrees to the join-line between the two adjacent components. The two returns (d) are similarly provided with a notch (1 1 ), cut with edges at 45 degrees to the join-line.
The punch provides the ends (6.1 ) of the flanges (b) on the jambs (2) with an offset lug (7) which, on assembly, extend beyond the end (6.2) of the adjacent flange (b) on the header (3). The lugs (7) locate inside the flanges (b) of the header (3) and each provides a shoulder (8) to abut the lip (c) on the flange (b) of the header (3).
The punch also provides means (9) and (10) on the components (2) and (3) to connect the jambs (2) to the header (3) at each of the two joints (5). The first connecting means provided at (9) holds the formed components together. Once the pressings are rolled, this connecting means will be common, overlapping lips (c) on the channel flanges (b) with an indent (1 1 ) providing a fold line between the header (3) and jambs (2).
The further connecting means (1 0) is provided as bendable tongue formations (10.1 ) locatable through slots (10.2) at the joints. The tongue formations (10.1 ) are formed as extensions on the lugs (7) adjacent the shoulders (8). The corresponding slots (10.2) are formed through the lips (c) on the header flanges (b).
Three additional tongues (1 0.3) are provided on the webs (a) of the jambs (2). Like the lugs (7), these tongues (10.3) are pressed downwardly to be offset from the remainder of the components (2) and (3). The portions of the pressings which are depressed in this way are indicated by hatching in the drawings.
The channel webs (a) of the jambs (2) are provided to abut the web (a) of the header (3). The web (a) of the latter extends to overlap those of the former at the two joints (5), on assembly. It is the ends of the abutting webs (a) of the jambs (2) that carry the three bendable tongue formations (10.3) which are stepped inwardly to the channel profile. These tongues (1 0.3) are locatable through corresponding slots (10.4) in the overlapping web (a).
After the cutting/pressing and rolling operations, the jambs (2) and header (3) form an approximately 5 meter long channel. A door frame (1 ) is easily assembled from the components.
The jambs (2) are bent out of alignment into a position where they are at 90 degrees to the header (3). The ends of the jambs (2) match up to the header (3) with the respective tongue formations fitting through the corresponding slots. The indents at (9) on the lips (c) between the components (2) and (3) provide for a neat fold on this line of reduced material thickness. Otherwise, the lip (c) would be prone to bending along a curve rather than as a neat corner. The profiled ends of the components (2) and (3) are thus configured to meet up in a 90 degree joint when pivoted about the hinge which is formed at the indent (1 1 ) on the lip (c). The connecting means (9) provided by the lips (c) provides a reinforcing strap which retains the components in position during and after the formation of the joints (5).
The offset of the tongue formations provide for a straight edge along the joint line visible from the inside of the door frame (1 ) where the webs (a) of the jambs (2) abut that of the header (3). The offset lug (7) is similarly not visible where the two 45 degree ends (6) of the flanges (b) meet but has the additional benefit of overlapping this part of the joint to conceal any gaps that may be present between the flange ends (6).
Once the tongue formations have been passed through the slots, they are bent to secure the components (2) and (3) in place. This can be conveniently done using a hammer. The components may optionally be further secured together by tack- welding on the exterior of the frame at the joint (5), where this will not be visible.
The arrangement of the shoulders (8) located against the lips (c) reinforces and braces the components (2) and (3) at the joint. This provides an added degree of strength at the flanged edges of the door frame (1 ) which makes it unnecessary to reinforce the frame with welding.
A suitable spreader (not shown) will be secured to the operatively lower ends of the jambs, to keep them parallel prior to installation. The combination of reinforcing shoulders (8) and connecting formations (10) enables simple and easy assembly of a door frame (1 ) which has good load bearing qualities even without any additional reinforcement. It is also anticipated that instead of keeping the components integral, they may also be separated by cutting the lips (c) along the indent at (9). This would usually be done for more convenience in transport and supply of the product. In such a case, the tongue and slot formations will be sufficient to secure the components (2) and (3) together for assembly of the door frame (1 ), with possible tack-welding.
Another embodiment of the invention is provided as a window frame (101 ). The window frame (101 ) is made of four main structural components; these are two opposite side stiles (102), a header (103) and a sill (104). The stiles (1 02) are in use connected to the header (103) and the sill (104) at four 90 degree corner joints providing a rectangular frame structure.
The components (102), (103) and (104) are similarly provided as a blank (101 A) with pieces of the sheet metal cut out between the components at (1 05.1 ) and at the ends of the blank (101 A) at (105.2). The components are provided in line on the sheet metal blank (101 A) as shown in Figure 6 and in the order of first stile (102.1 ), header (103), second stile (102.2) and sill (104).
Unlike the door frame, the two free ends of the blank (101 A) are configured for cooperating engagement; these ends are respectively the same as the adjacent ends of the components which remain connected in the length of the blank (101 A).
The rolled channel profile is indicated by (101 B) in Figures 7 and 8. The channel (101 B) has a web (a) with two lipped flanges (b). A return (d) is also provided along the length of each of the lips (c). One of the flanges is smaller than the other to accommodate a double inward step which is rolled into the web (a).
The ends (106) of the flanges (b) are provided at 45 degrees in the manner required to meet at the 90 degree joints between the components. Each end (106.1 ) of a flange (b) on the stile (102) has an offset lug (1 07) which, on construction of a joint, extends beyond the end (106.2) of the adjacent flange (b). The lugs (107) locate inside the adjacent flanges (b) and each provides a shoulder (108) to abut the lip (c) on the adjacent flange (b).
A first connecting means is provided at (1 09) as common, overlapping lips (c) on the channel flanges (b) provided with an indent (1 1 1 ) for a fold line.
Further connecting means (1 10) are provided as bendable tongue formations locatable through slots at the joints. These connecting means (1 1 0) are also present at the outer ends of the blank (101 A) respectively and are necessary to secure these ends together when the frame (101 ) is assembled.
Tongue formations (1 10.1 ) are formed as extensions on the lugs (107) with corresponding slots (1 10.2) through lips (c). Three additional, downwardly pressed tongues (1 10.3) are also provided on the webs (a) of the channels. The channel webs (a) have the same abutting and overlapping relationship as those of the door frame, on assembly. Operatively oppositely disposed T-shaped slots (121 ) and hinge pin holes (1 22) in the header (103) and sill (102) are also provided by a punch. The T-slots (121 ) will receive a T13 window section profile as part of the assembled frame. The holes (122) will similarly receive the two hinge pins on a window opener. A further slot (123) is also punched into the sill (104). A round nose component, for mounting a sliding adjuster for the window opener, will be secured in this slot (123). After the pressing and rolling operations, the components (102), (103) and (104) form an elongate channel (101 B) from which a window frame (101 ) is easily assembled.
Starting at one end, the components are bent out of alignment into the position for constructing a joint. The respective adjacent ends of the components with the tongue formations match up to those with the corresponding slots. The return (d) which extends along the length of each of the lips (c) - for both the door and window frames - is significant in that it enables a frame to be made from thinner sheet metal but with suitable strength. For example, sheet metal of 0.6 mm can be used instead of 0.9 mm and still provide a frame which has the required structural integrity.
In addition to the lips (c) which connect the adjacent components, one or more bands of the sheet metal may be left connecting the components between the web portions (a) of the channel. These bands will bulge outwardly on assembly of the frame and can be twisted tight with pliers or some other lever, such as a screwdriver. This provides additional connecting means to add to the rigidity of the assembled frame. A groove may be pressed into each band where it connects to the web (a) - this will allow a neat bend or fold, without any bending or distortion of the web (a) where the band connects thereto. The frame provided in accordance with the invention is convenient to assemble and is sufficiently strong to be relied on to reinforce a building structure around windows and doors. A frame of this kind may allow the requirement of lintels to be dispensed with. The frame thus provides a high degree of structural integrity and lends itself to low cost housing. It is however equally neat with clean join lines and no visible welding marks once installed and can be used in any door or window frame applications.
A person skilled in the art will appreciate that a number of changes may be made to the features of the embodiment described without departing from the scope of the invention.