Structural Member

Abstract: An I-section structural member (30) for hollow partition walls comprising two flanges (32,33) separated by a web (34) is disclosed. Holes (36) for electrical cabling (44) extend through the edge portions of the web (34) adjacent the flanges (32,33), allowing the cabling (44) to run adjacent the inner surface of one panel of the partition wall.

Description: The present invention relates to a structural member for a hollow partition wall such as a nogging for use in the construction of hollow partition walls. The use of plasterboard in partition walls is well known. In a conventional system, the plasterboard is employed as cladding over a rigid framework, usually formed from standard metal or wood components. Cladding panels of materials other than plasterboard are also known. Reference should now be made to Figure 1 which shows schematically details of the framework concealed within a plasterboard partition wall. The framework is assembled in situ by firstly fixing channels 10 to the ceiling and floor aligned in the plane the partition wall is to occupy. I-section studs 12 are placed in the floor and ceiling channels 10 and aligned vertically before being fixed into position. Between each pair of studs 12, a nogging 14 is inserted at mid height. The ends of the nogging 14 engage the profiled sides of the studs 12, forming a horizontal brace when secured in position. Electrical cables, conduits and pipes can readily be accommodated within the cavity of a hollow partition wall. Typically, these services are installed at the same time as the wall is constructed. Having erected the framework, it is common practice to fix initially plasterboard to one side only of the framework so that services can be installed from the other side. Suppose that an electrical switch 16 is to be provided on one side of the partition wall in a position above the nogging 14. Electrical cable for the switch 16 which is concealed within the partition wall should be installed in straight runs, either horizontally or vertically. It should be a reasonable depth such as 50mm from the face of the partition wall not having any indication such as a switch that a cable has been installed in the cavity. In order for the electrical cable 18 to be installed vertically between the switch 16 and the floor channel 10, it passes through a standard cut-out 20 from the web of the nogging, aligned along the longitudinal axis of the nogging 14. The cut-out 20 may be lined with a rubber grommet to prevent abrasion of the cable by the nogging 14. Studs 12 and noggings 14 typically have several cut-outs along their length to facilitate the positioning of service installations which must pass through frameworks utilising these components. US-A-5 081 808 discloses a partition system including a C-section frame member having openings for the passage of electrical cabling. FR-A-2 643 700 discloses a structural member of hollow rectangular cross section having longitudinal rows of holes. The holes receive rivets to join the members to clips for retaining cladding panels and are disposed either side of the centre lines of opposed faces of the member. NL-A-7 908 371 discloses a substantially C section member with an aperture on the centre line of the web of the member, midway between the two longitudinal flanges, for receiving electrical cabling. The present applicants have appreciated that there is a desire to reduce the overall thickness of partition walls in order to reduce the amount of space lost as a result of constructing a partition wall. In accordance with the present invention there is provided a structural member for a hollow partition wall having two longitudinal flanges for supporting the outer faces of the partition wall, the flanges being separated by a web having at least one aperture for receiving electrical cable characterised in that the or each aperture is disposed in an edge portion of the web adjacent a flange. The invention also encompasses a wall especially a partition wall comprising such a structural member. By providing the aperture for the electrical cable adjacent a flange, it is possible to pin the cable against the inner surface of one of the cladding panels (the panel carrying the switch) of the partition wall. This ensures that the cable is as far away from the opposed panel as possible, even when passing through the support structure. In this way, it is possible to install cable for a switch in a relatively thin partition wall, say 75mm total thickness, and still have the cable a reasonable depth, such as 50mm, from the panel of the partition wall not carrying the switch. Preferably, apertures are disposed in both edge portions of the web, adjacent both flanges. More preferably, apertures in one edge portion of the web are offset relative to apertures in the other edge portion. The apertures can be semi-circular, square or other rectangular or of any other shape. Providing apertures in both edge portions of the web and in offset positions gives additional flexibility in aligning the structural member in the framework of a partition wall with service points which are to be installed. An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a schematic view illustrating a prior art framework concealed in a conventional plasterboard partition wall; Figure 2 is a perspective view of part of a nogging embodying the invention; and Figure 3 is a schematic cross-sectional view through a hollow partition wall, illustrating the advantages of the nogging of figure 2. Figure 2 shows a nogging 30 which is elongate and has two longitudinal flanges 32 and 33 which are parallel to each other. The flanges 32, 33 are separated by a web 34 which has along its length a plurality of semi-circular apertures 36 for passing electrical cable therethrough. The apertures 36 are disposed on either side of the web 34, adjacent the flanges 32, 33. The aperture 36 obscured in the drawing by flange 32 is shown by a phantom line. The nogging 30 has an I-shaped cross-section. The nogging is formed from a sheet of metal into which two rows of circular apertures are punched. The sheet is then folded at right angles along two parallel lines bisecting the circular apertures. The lateral sides of the sheet are then folded double to give the I-shaped cross-section. At the longitudinal ends of the nogging, the web can be swaged. Swaging makes it easier to reduce the separation between the flanges 32, 33 in the region of the swage 38 by squeezing the flanges together. This enables the end of the nogging 30 to be inserted into the profile of a stud for example. Once in position, the end of the nogging 30 will adopt a compression fit in the throat of the stud section 12. The nogging 30 can be used in place of the nogging 14 in the assembly shown in Figure 1. Figure 3 shows schematically the cross-section of a thin partition wall illustrating how the nogging 30 is used in combination with electrical cable. The flanges 32 and 33 of the nogging 30 abut plasterboard cladding sheets 40 and 41. A switch 42 is mounted in sheet 41 and is connected to electrical cable 44. The cable 44 runs vertically downwards adjacent the inner surface of sheet 41, passing through an aperture 36 in the web 34 of nogging 30. The aperture 36 is lined with a grommet 46 to prevent the cable being abraded by the metal nogging 30. The cable 44 is concealed at a depth X from the outer surface of sheet 40. The depth X is at least 50mm even though the overall thickness of the partition wall is no greater than 75mm.

Claims: A structural member (30) for a hollow partition wall having two longitudinal flanges (32,33)for supporting the outer faces of the partition wall, the flanges being separated by a web (34) having at least one aperture (36) for receiving electrical cable, characterised in that the or each aperture is disposed in an edge portion of the web (34) abutting one of the longitudinal flanges (32,33). A structural member (30) according to claim 1 in which apertures (36) are disposed in both edge portions of the web (34) abutting both flanges (32,33). A structural member (30) according to claim 2 in which apertures (36) in the web (34) abutting one flange (32) are offset relative to apertures abutting the other flange (33). A structural member (30) according to any preceding claim in which the flanges (32,33) and web (34) form an I-section. A structural member (30) according to any preceding claim in which the or each aperture (36) is semi-circular. A structural member (30) according to any of claims 1 to 4 in which the or each aperture is rectangular. A structural member (30) according to any of claims 1 to 4 in which the or each aperture is square. A method of forming a structural member (30) for a hollow partition wall having two longitudinal flanges (32,33) for supporting the outer faces of the partition wall, comprising: forming a longitudinal line of perforations in a strip of material; and folding the strip longitudinally along the perforations to define a web (34), a flange (32,33) and at least one aperture (36) in the web abutting one of the longitudinal flanges (32,33). A method according to claim 8 in which a further line of perforations is formed parallel to the first, and in which a further longitudinal fold is made parallel to the first fold. A method according to claim 8 or 9 in which the strip is further folded double longitudinally parallel to and on the outside of the or each line of perforations. A wall comprising a structural member (30) according to any of claims 1 to 7. A wall according to claim 11 in which the structural member (30) is substantially horizontal. A partition wall according to claim 11 or 12. A partition wall comprising a framework comprising vertical studs (12) extending between the floor and the ceiling and horizontal noggins (14) disposed horizontally between pairs of studs; and plasterboard cladding attached to the framework, characterised in that the noggin is a structural member according to any of claims 1 to 7.

Inventors: NELSON JOHN ALEXANDER, PRITCHARD MICHAEL JOHN, NELSON, JOHN ALEXANDER, PRITCHARD, MICHAEL JOHN
Applicants: BPB PLC
Application year: 1996
Main classification: E04B2
IPC codes: E04B2