Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
(i) Field of the Invention
This invention relates to a building construction and, more particular,
relates to a
metal truss, metal components thereof, and to light weight framing structures
constructed
of said metal truss.
(ii) Description of the Related Art
Open-web floor joists and roof rafters having wooden upper and lower wooden
chords joined at equispaced intervals by U-shaped metal diagonals are known.
The truss
construction has the advantage over solid wooden joists and rafters of
permitting utilities
such as plumbing, electrical wiring and ventilation ductwork to freely pass
through open
spaces in the trusses, while using up to 30% less material.
Light-weight structural framing systems comprised of solid metal channel and I-
beam studs and top and bottom horizontal tracks and bridging channels joined
by sheet
metal angle brackets and gussets using sheet metal screws or by tack welds are
also known.
The webs of the channel and I-beam joists are closed, necessitating the costly
drilling or
cutting of the webs by skilled workmen to allow utilities to pass through.
It is an object of the of the present invention therefore to provide a
relatively
inexpensive, light-weight, metal framing structure using a novel truss
construction for floor
joists, roof rafters and wall studs.
It is another object of the present invention to provide a building system
having
structural integrity for winds up to hurricane force and for severe
earthquakes.
Another object of the invention is the provision of a building system which
can be
erected by local workmen after a brief training program.
~mar~~ of the Invention
In its broad aspect, the metal truss of the invention for use as wall studs,
floor joists
and roof rafters comprises a pair of parallel, spaced-apart elongated metal
tubes, preferably
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having a rectangular cross-section, having a plurality of diagonal members
equispaced
along said pair of tubes for interconnecting the tubes, said diagonal members
being
arranged in V-shaped pairs with a diagonal member of each pair being
attachable on
opposite sides of the elongated metal tubes, and connector means for joining
the diagonal
members to the elongated metal tubes. The diagonal members comprise elongated
plates
having flanged sides and enlarged end plates at each end thereof to facilitate
assembly of
the truss, the enlarged ends preferably being enlarged and oblique to the
elongated plate.
The metal truss additionally comprises thermal break pads of a heat insulating
material
such as rubber, rubberized plastic or plastic between the diagonal members and
the
elongated metal tubes. A thermal break material can be disposed on the
exterior wall faces
of the trusses, such as on the outside faces of wall studs and rafters. The
elongated metal
tubes are formed from 18 to 26 gauge galvanized steel and the diagonal members
are
formed of 16 to 18 gauge galvanized steel, and the connector means are self
tapping
galvanized steel screws.
Brief Description of the Drawings
The metal truss of the invention and the related building system will now be
discussed by way of example, with reference to the accompanying drawings in
which:
Figure 1 is an elevation view, partly cut-away of an upper portion of the
overall building system;
Figure 2 is an elevation view, partly cut-away of a lower portion of the
building system, showing the manner in which a metal floor joist
may rest upon a concrete foundation and a metal wall stud may rest
upon the metal floor joist;
Figure 3 is an elevation view of a metal floor joist;
Figure 4 is a vertical section view of the metal floor joist shown in Figure
3,
showing section views of the top and bottom chords;
Figure 5 is an enlarged vertical section view of a metal truss or metal wall
stud or metal floor joist, showing the thermal break connection;
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Figure 6 is a perspective view of the bottom of one embodiment of a metal
diagonal;
Figure 7 is a perspective view of the top of the aforesaid embodiment of a
metal diagonal showing thermal insulators separated therefrom;
Figure 8 is a perspective view of an alternative embodiment of a metal
diagonal;
Figure 9 is a side elevation view of the aforesaid alternative embodiment of
a metal diagonal;
Figure 10 is an end elevation view of the aforesaid alternative embodiment of
a metal diagonal, viewed from the left of Figure 9;
Figure 11 is a perspective view of a further alternative embodiment of a metal
diagonal;
Figure 12 is a side elevation thereof;
Figure 13 is an end view thereof; and
Figure 14 is a perspective view of a still further embodiment of a metal
diagonal.
Description of the Preferred Embodiments
The metal truss of the invention, as shown in the drawings, comprises metal
floor joist trusses, metal wall stud trusses, and metal roof rafter trusses
which can be
factory assembled or transported to a building site for assembly. Exterior
wall stud trusses
and floor joist trusses are typified in Figures 1 and 2. Wall stud truss 10
consists of
formed, rolled or extruded parallel metal chord tubes 12, 14 joined by a
plurality of
equispaced diagonal members 16 on each side thereof. Each diagonal member 16
preferably has enlarged oblique end plates 18 formed integral therewith at an
angle to the
long axis of the diagonal member to correspond to the long axis of the chord
tubes
whereby each diagonal member can be secured to the chord tubes at the desired
diagonal
angle to facilitate assembly and to maintain correct parallel spacing of tubes
12, 14.
End plates 18 preferably have two or three holes 19 formed therein for
receiving
and starting self tapping metal screws for screwing into chord tubes 12, 14 to
secure the
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diagonal members 16 to the chord tubes. Plastic or rubberized plastic thermal
insulator
sheets or pads 17 about one-quarter inch thick are placed between diagonal
members 16
and chord tubes 12, 14.
The chord tubes and diagonal members preferably are formed from galvanized
steel, the exterior wall components, floor joists and roof trusses formed of
zinc-coated light
steel and interior wall studs formed for example of 26 gauge galvanized steel.
The
elongated metal tubes preferably are formed of 18 to 26 gauge galvanized steel
and the
diagonal members of 16 or 18 gauge galvanized steel.
Figure 1 also illustrates a conventional roof truss assembly 20 preferably
fabricated
from metal components and seated on the upper end 22 of wall stud 10. Roof
truss 20 has
chord tubes 24 interconnected by screws 21 with insulator pads 23 for a
thermal break.
It will be understood that roof rafter trusses similar to wall stud trusses 10
or floor joist
trusses 30, to be described, can be employed in place of truss assembly 20 to
provide an
open, cathedral or vaulted ceiling effect.
With reference now to Figures 2 - 5, floor joist trusses 30 seated on concrete
wall
or pier 31 consist of an upper metal chord tube 32 and a parallel lower metal
tension chord
tube 34 of lesser depth secured thereto by a plurality of equispaced diagonal
members 36
having enlarged end plates 40, 42 formed integral therewith having a size to
correspond
with the depth of chord tubes 32, 34, as shown most clearly in Figures 2 and
3. Self
tapping metal screws 44 secure diagonal members 36 to the chord tubes 32, 34
with plastic
or rubberized plastic thermal break sheets or pads 46 insulating the metal
components from
each other. It may be preferred to cover the exterior faces of wall stud
trusses 10 with a
thermal break strip 47 (Figure 2) to obviate insulator pads 17.
Figures 6 and 7 illustrate in more detail the construction of diagonal members
16
or 36 having side flanges 50, 52 for rigidity. Figure 7 shows thermal break
insulators 46,
48.
Figures 8 - 10 show another embodiment of diagonal member 60 for securement
to opposite sides of chord tubes. Each member is a closed tube 62 with
connecting
brackets or plates 64, 66 extending from opposite sides from opposite ends
thereof. Each
diagonal member is secured to the chord tubes of stud trusses, joist trusses
or rafter trusses
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from opposite sides of diagonal members 60 by metal screws through plate holes
68.
Figures 11 - 13 illustrate another embodiment of diagonal member 70 with a
pair
of connecting brackets 72, 74 at each end thereof for straddling a metal chord
tube and for
securement by self tapping metal screws from both sides of diagonal member 70.
Figure 14 shows another embodiment of diagonal member 80 with end flanges 82,
84 at opposite ends on the same side thereof.
Typical wall studs 10 are formed of galvanized steel tubes 1.5" x 1.5" square
interconnected by galvanized steel diagonals 4" to 12" long using steel self
tapping screws,
or by welds. Floor joists 30, of the same construction, preferably have an
upper
compression chord tube larger than the lower tension chord tube, e.g. 2.5" x
1.5" upper
tube and 1.5" x 1.5" lower tube, or may have 3.5" x 1.5" upper and lower
tubes. Roof
trusses may be fabricated of 1.5" x 1.5" upper and lower steel tubes, 2.5" x
2.5" upper
and lower steel tubes, or 3.0" x 1.5" upper and lower tubes, depending on
truss length and
anticipated loading. The diagonal members preferably are arranged in V-shaped
pairs and
connected on opposite sides of the chord tubes to provide torsional rigidity
to the trusses.
Thermal insulating pads retard heat transfer and insulate the metal components
from each
other.
It will be understood that modifications can be made in the embodiment of the
invention described herein without departing from the scope and purview of the
invention
as defined by the appended claims.
