Structural support

A structural support made of sheet metal or like material has a surface (2,3) intended to support a building panel or some other structural member, which is secured to the surface by means of screws or like fasteners. In order to reduce the force required to drive the screws or like fasteners, such as nails, into the support, the aforementioned surface is provided with closely lying weakened areas within a fastening area (9,10), the points of the fasteners being guided into the weakened areas by inclined surfaces adjacent thereto.

The present invention relates to a structural support made, for example, of 
sheet metal and intended to support a building panel or some other 
structural member which can be fastened to a surface on the support by 
means of nails, screws or similar fasteners, said surface having therein 
weakened portions for receiving said fasteners. 
Structural supports of this kind are known from, for example, CH-A-619 035, 
which describes a structural support provided with fastener-receiving 
apertures. The apertures are spaced relatively widely apart, and 
consequently each nail or screw must be placed in a specific position on a 
panel in order for the point of the fastener to engage the aperture in the 
support, said aperture naturally being hidden by the panel. If the 
fastener strikes to one side of the aperture in the support, a fresh 
attempt must be made. Structural supports of this kind are only suitable 
for use when securing panels, shelving brackets or other structural 
members which have been pre-drilled. 
Normal supports of this kind, used for example in inside walls or partition 
walls, and in ceiling structures, are made from sheet steel. The material 
thickness of a sheet-steel structural support is about 0.5-3.0 mm. When a 
panel is to be secured to such a support, there is normally used special, 
hardened self-tapping steel screws, having points capable of being forced 
through the plate. Despite the use of special screws, the force required 
to drive the self-tapping screws lies within a range of 25-35 kp, placing 
much strain on the workman, particularly since normally 5000 screws are 
required each day. Consequently, those workmen whose task it is to set up 
the panels etc., often suffer from such ailments as aching arms and backs. 
One object of the invention is to provide a structural support where the 
force required to drive a screw thereinto is only about 1-5 kp, thereby 
greatly lowering the individual strain on the joints and muscles of the 
arms, shoulders and back of the workmen. 
Another object of the invention is to provide a structural support formed 
from a relatively small amount of material, and therewith a support of 
relatively light weight, and which enables the use of inexpensive 
fasteners and has low energy-transmission properties, especially with 
respect to the transmission of acoustic energy.

FIG. 1 is a sectional view of an inside wall or partition wall of a 
building, said wall comprising a plurality of sheet-metal supports 1 
having surfaces 2 and 3 which, in the illustrated embodiment, are shown to 
be planar, but which may have any suitable form and may, for example, be 
corrugated. These surfaces 2 and 3 are intended to support thereagainst 
structural elements, such as shelving brackets or, as in the illustrated 
case, building panels 4, 5 and 6, comprising, for example, plaster board 
or metal facing panels or ceiling/roofing panels or the like. 
Conventionally, the panels, such as the panel 4 are secured by means of 
screws 7, which have a specially formed point 8, which when a large axial 
force is imparted to the screw, for example a force of 25 kp, cuts through 
the metal and forms an opening, into which the self-tapping screw can be 
screwed. 
FIG. 2 illustrates a structural support of substantially C-shaped 
cross-section and of the same kind as that shown in FIG. 1. In this 
embodiment, however, the structural support is provided with fastening 
areas 9 and 10 on both planar surfaces 2 and 3. As will best be seen from 
the enlarged views in FIGS. 3 and 4, these fastening areas comprise 
perforated areas on the support. In the FIG. 3 embodiment, the fastening 
areas 9 and 10 comprise areas of expanded metal, forming rhomboidal 
apertures, such as apertures 11 and 12. Each aperture is defined by narrow 
metal bands 13, 14, 15 and 16. The size of the screw or like fastener used 
to secure the sheet or building panel to the structural support is adapted 
to the smallest dimension 17 of the aperture. FIG. 3 illustrates in 
cross-section a screw having a core 18 and threads 19. When the screw 
enters the aperture and begins to screw into the panel, the core 18 will 
force out the aperture, defining bands 13, 14, 15 and 16, and the screw 
will obtain a positive grip. The force required to drive in the screw is 
relatively small, for example from 1-5 kp. If the point of the screw 
should come into contact with metal lying adjacent an aperture, for 
example into contact with the metal shown at the location 20, the point 
will be guided into the adjacent aperture, so that the screw or like 
fastener is firmly seated in the manner desired. In accordance with the 
invention, this guiding of the end of a fastener is ensured by inclining 
the material surfaces between the apertures, as illustrated in FIG. 4. 
Inter alia, FIG. 4 is a sectional view of the band 15, which is shown to 
have a rectangular cross-sectional shape. In manufacturing the grid, all 
bands, for example the band 15, have been rotated about their longitudinal 
axes, so that the surfaces 15a, 15b, 15c and 15d are inclined to the 
direction in which the fastener is driven. Consequently, if the end of a 
screw, nail or like fastener engages the structural support on one side of 
an aperture, the material engaged by the end of said fastener will not be 
pressed inwardly, which might exclude the possibility of effectively 
driving home the fastener, but will be moved sideways by the laterally 
acting force presented through the nearest inclined surface. When seen 
theoretically, this means that either the fastener can move laterally 
slightly, into the panel, or corresponding movements take place by 
stretching and compression laterally in the fastening surface on the 
structural support. This latter is constructed to take up such movement, 
since the material can be stretched in the propagation plane. As will be 
understood, even when the diameter of the core 18 is larger than the 
smallest aperture dimension 17, the only requirement is for the threads of 
the screw to engage the edges of the aperture. 
FIG. 5 illustrates an embodiment of a structural support having two flanges 
21 and 22 which are intended to be secured to a ceiling or like structure, 
each of the flanges of the illustrated structural support being provided 
with fastener-receiving areas 23 and 24 in accordance with FIGS. 3 and 4. 
A fastening surface 25 is provided with a weakened area 28 by means of 
bent sections 26, 27. 
In regions located between the perforated areas 23, 24, 28, the metal 
support is continuous, so as to obtain the maximum stability and rigidity 
in the structural support. 
As will be understood, the structural support illustrated in FIG. 2 can 
well be manufactured totally from expanded metal or from any other type of 
perforated metal sheet. 
FIG. 6 illustrates a structural support of a kind which includes 
fastener-receiving areas 29 and 30, and areas 31 and 32 on the web 33, 
which are formed in a manner to save material and which are separated from 
the areas 29 and 30 by means of stiff angle plates 34 and 35, for greatly 
stiffening the structural support. Between the two perforated areas 31 and 
32 of the web 33, which perforations may, for example, have the same 
dimensions as the perforations within the fastening areas 29 and 30, there 
is arranged along the support an area 36 which is similar to the other 
areas and which includes preferably thin strips, for example strips 37 and 
38, which hold the support together and which are formed in accordance 
with an expanded metal technique. These strips 37 and 38 can be readily 
clipped off or knocked away when drawing, for example, electric cables 
into the wall and, because of the small amount of material within the area 
36, cause the transmission of energy from one side of the support to the 
other to be greatly reduced. This support connecting area 36 can, of 
course, be formed in a different way, for example, by punching rectangular 
pieces from the metal sheet, to leave thin, readily broken strips. The 
weakened portions also enable the structural supports to be clipped and 
holes for installation lines to be made therein much more readily. 
In the aforegoing it has been assumed that the structural support is made 
from a homogenous material, for example sheet metal, although it is also 
conceivable to use composite material. For example, practical experiments 
have shown that tubular beams made of paperboard which is coated with, for 
example, a thermosetting resin, subsequent to pressing a grid of, for 
example, the kind shown in FIG. 3, firmly into the paper-board material, 
preferably on the inside of the beam, exhibits sufficient strength and 
stability to be used, for example, in the construction of partition walls 
and inner walls in a building. 
The structural support, or at least those parts thereof which form 
fastener-receiving surfaces for such fasteners as screws, nails etc., may 
have the form of a net structure of desired mesh size. The net structure 
may, for example, be constructed from metal wires or rods welded together 
to form meshes of, for example, rectangular configuration. 
In the aforegoing the invention has been described with reference to the 
construction of buildings. As will be understood, however, the invention 
can also be applied in all cases where a structural member or the like is 
to be fastened to a structural support. For example, there are widely used 
in the electronic industry frame structures or chassis to which such 
components as transformers, circuit blocks etc., are screwed. In this case 
the chassis forms the aforedescribed structural support and is provided 
with weakened areas according to the invention. There is also found a need 
for the invention in the car-manufacturing industry, the invention 
enabling components to be mounted, for example, on the car body more 
simply and more readily, the car body forming, in this case the described 
support member, in which fastener-receiving weakened areas are formed at 
desired locations when pressing the body platework.