U.S. patent application number 13/261589 was filed with the patent office on 2013-10-10 for building panels.
The applicant listed for this patent is Stuart Harry Robertshaw. Invention is credited to Stuart Harry Robertshaw.
Application Number | 20130266793 13/261589 |
Document ID | / |
Family ID | 43980758 |
Filed Date | 2013-10-10 |
United States Patent
Application |
20130266793 |
Kind Code |
A1 |
Robertshaw; Stuart Harry |
October 10, 2013 |
BUILDING PANELS
Abstract
A building panel incorporates blocks (11) of a low density
material contained within a surrounding wire support cage (12). The
cage is formed from a plurality of wire trusses (1) which are
spaced apart such that each truss separates adjacent low density
blocks, and the trusses are held together by strapping wires (14)
which are encased within layers of render (15, 16) in use. The
truss has opposing longitudinally extending reinforcing wires (2,
3) to which the strapping wires (14) are connected, and
intermediate wires (4) which are preferably formed in a zig-zag.
Each truss includes at least one additional wire (5) which extends
longitudinally of the truss.
Inventors: |
Robertshaw; Stuart Harry;
(Halifax, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Robertshaw; Stuart Harry |
Halifax |
|
GB |
|
|
Family ID: |
43980758 |
Appl. No.: |
13/261589 |
Filed: |
July 18, 2010 |
PCT Filed: |
July 18, 2010 |
PCT NO: |
PCT/EP2010/060374 |
371 Date: |
June 6, 2013 |
Current U.S.
Class: |
428/223 |
Current CPC
Class: |
E04B 2/845 20130101;
E04C 2/06 20130101; E04C 2/044 20130101; E04B 2/86 20130101; Y10T
428/249923 20150401; E04B 2/847 20130101; E04C 2/288 20130101 |
Class at
Publication: |
428/223 |
International
Class: |
E04B 2/86 20060101
E04B002/86 |
Claims
1. A building panel comprising blocks (11) of a low density
material contained within a surrounding support cage (12), in which
the cage comprises a plurality of wire trusses (1) extending along
a length of the panel, the trusses being spaced apart such that
each truss separates adjacent low density blocks, in which each
truss comprises a pair of substantially parallel longitudinally
extending reinforcing wires (2, 3) located on opposite sides of the
low density blocks, and the trusses are held together by strapping
wires (14) joined to the reinforcing wires on opposite sides of the
panel, wherein each truss (1) includes a plurality of intermediate
wires (4, 5) which travel along the length of the truss between the
low density blocks (11).
2. A building panel according to claim 1 in which the intermediate
wires include at least one transverse wire (4) which meanders
between the reinforcing wires (2, 3) as it travels along the length
of the truss.
3. A building panel according to claim 2 in which the or each
transverse wire (4) travels in a zig-zag path along the length of
the truss.
4. A building panel according to claim 2 in which the intermediate
wires include at least one tie wire (5) which extends
longitudinally of the truss, spaced from the reinforcing wires (2,
3).
5. A building panel according to claim 4 in which the or each tie
wire (5) is joined to a transverse wire (4).
6. A building panel according to claim 5 in which the or each tie
wire (5) is joined to a zig-zag transverse wire (4) part-way
between the zig-zag bends.
7. A building panel according to claim 5 in which the or each tie
wire (5) is joined to two or more transverse wires (4).
8. A building panel according to claim 3 in which the
longitudinally extending reinforcing wires (2, 3) are inset from
the bends in the zig-zag transverse wires (4).
9. A building panel according to claim 2 in which the cut ends of
the transverse wires (4) are joined to the reinforcing wires (2,
3).
10. A building panel according to claim 4 in which the cut ends of
the tie wires (5) are joined to the transverse wires (4).
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to building panels of the kind which
comprise a wire reinforcing cage enclosing a low density core.
BACKGROUND
[0002] Buildings are sometimes constructed from off-site
construction building panels (also known as prefabricated building
panels) which have a low core of low density material held in a
wire reinforcing cage. For example, GB 2 323 404 A describes
building panels which are fabricated from welded wire trusses
sandwiched between blocks of foamed plastics material, e.g.
phenolic foam. In this instance zig-zag warren trusses are used
which are held together by horizontal strapping wires to form the
cage around the blocks. The width of the cage is typically about 75
mm whereas the width of the foam core is typically around 50 mm so
that the cage extends approximately 10 mm or so on either side of
the core. A layer of cement or plaster, produced on site, is
applied to each side of the core. The finished thickness of the
wall, including the cement/plaster layers, is typically around 95
to 100 mm. Such panels, which are typically of the order of 1.2 m
high and 2.4 m wide, are relatively light and easily handled and
may be cut to any desired shape if necessary. The panels may be
used to construct internal and external walls as well as roofs and
multi-storey floors.
[0003] Buildings are constructed by arranging the building panels
adjacent to one another on a foundation to which the panels are
anchored. Adjacent panels may be tied to one another by securing
each panel to a strip of reinforcing mesh. Once wall and roof
panels have been erected, internal and external surfaces of the
panels are rendered to provide a finished surface. For instance,
the external render may typically comprise a weatherproofing mix of
Portland cement and sand. Alternatives, such as gypsum plaster,
might typically be used for rendering internal surfaces. The layer
of cement or plaster encases the wire mesh cage on both sides of
the foam core producing a strong and rigid structure when dry. If
desired, various waterproofing, anti-fungal and fibre reinforcing
agents may be applied to the rendering mixture or the dried
surface.
[0004] Whilst such building panels are not difficult to manufacture
and are generally convenient to handle and erect, they are not
sufficiently load bearing to enable construction of multi-storey
buildings without additional supporting structure. GB 2 323 404 A
proposes constructing multi-storey buildings by including vertical
"I" section columns erected at spaced apart locations around the
building perimeter which support horizontal "U" section steel
members which span adjacent columns, and which may be supported
intermediate adjacent columns by vertical props. This structure
provides additional support for second and subsequent stories which
are erected in the same manner by securing further vertical columns
to the ground floor columns, and adding additional horizontal
channel members and props if necessary.
[0005] A further important requirement in buildings formed from
lightweight building panels is that the structure should have high
resistance to forces such as high winds and earthquakes.
[0006] In a move towards increasing the insulation value of
buildings, it has become desirable to increase the insulation
thickness from around 50 mm to as much as 300 mm or more. However,
in walls having a single panel thickness such significant increases
in dimensions require a substantial increase in wire diameter in
order to retain sufficient structural rigidity. This not only
significantly increases the costs, but also produces a considerable
increase in weight, making the panels much more difficult to
handle.
[0007] Ladder trusses are also known, although they are generally
not as strong on a weight-for-weight basis as zig-zag warren
trusses.
[0008] It is an object of the present invention to provide a
building panel of improved load bearing capabilities whilst also
meeting the requirements for improved heat insulation properties,
low cost and low weight.
SUMMARY OF THE INVENTION
[0009] The present invention proposes a building panel comprising
blocks of a low density material contained within a surrounding
support cage, in which the cage comprises a plurality of wire
trusses extending along a length of the panel, the trusses being
spaced apart such that each truss separates adjacent low density
blocks, in which each truss comprises a pair of substantially
parallel longitudinally extending reinforcing wires located on
opposite sides of the low density blocks, and the trusses are held
together by strapping wires joined to the reinforcing wires on
opposite sides of the panel, [0010] wherein each truss includes a
plurality of intermediate wires which travel along the length of
the truss between the low density blocks.
[0011] The intermediate wires preferably comprise at least one
transverse wire which meanders between the reinforcing wires as it
travels along the length of the truss. In a preferred form of truss
the or each transverse wire preferably travels in a zig-zag path
along the length of the truss.
[0012] The intermediate wires preferably include at least one tie
wire which extends longitudinally of the truss, spaced from the
reinforcing wires. The or each tie wire is preferably joined to a
transverse wire.
[0013] The cut ends of the intermediate wires may be joined to the
reinforcing wires, or they may be joined to a cross element which
bridges the reinforcing wires.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The following description and the accompanying drawings
referred to therein are included by way of non-limiting example in
order to illustrate how the invention may be put into practice. In
the drawings:
[0015] FIG. 1 is a side view of a short length of a first form of
truss for use in a building panel;
[0016] FIG. 2 is a general schematic representation of a building
panel constructed from the trusses, in accordance with the
invention;
[0017] FIG. 3 is a side view of a second form of truss which can be
used in a building panel in accordance with the invention; and
[0018] FIG. 4 is a side view of a third form of truss which can be
used in a building panel in accordance with the invention;
[0019] FIG. 5 is a side view of a fourth form of truss which can be
used in a building panel in accordance with the invention;
[0020] FIG. 6 is a side view of the first form of truss, showing a
method of end termination;
[0021] FIG. 7 is a side view of the first form of truss showing an
alternative method of end termination;
[0022] FIG. 8 is a side view of a fifth form of truss which can be
used in a building panel in accordance with the invention;
[0023] FIG. 9 is a side view of the first form of truss showing yet
another method of end termination; and
[0024] FIGS. 10 to 14 are side views showing different variations
of the second form of truss.
DETAILED DESCRIPTION OF THE DRAWINGS
[0025] Referring firstly to FIG. 1, the truss 1 is formed of a pair
of substantially parallel longitudinal reinforcing wires 2 and 3
and two intermediate wires 4 and 5, including a single transverse
wire 4 which travels along the length of the truss in a zig-zag
manner. The angular bends of the zig-zag wire 4 are welded to
alternate wires 2 and 3, forming a series of rigid triangles. In
accordance with the invention the truss includes a further
intermediate wire in the form of a tie wire 5 which extends
longitudinally substantially mid-way between the wires 2 and 3,
welded to the zig-zag wire 4 at the points where the tie wire
crosses the zig-zag wire.
[0026] FIG. 2 shows an off-site construction building panel using
trusses of the kind just described. The panel 10 includes a core of
low density blocks 11, e.g. of expanded polystyrene, held within a
wire cage 12. The panel is formed by stacking the blocks 11 and
trusses 1, with a truss 1 sandwiched between pairs of blocks 11.
The distance between the longitudinal reinforcing wires 2 and 3 is
greater than the width of the blocks so that the reinforcing wires
lie on opposite sides of the low density core. The wires 3 on one
side of the core are joined together by parallel strapping wires 14
which are welded perpendicularly to the wires 3. On the opposite
side of the core the reinforcing wires 2 are similarly welded to a
further set of strapping wires 14. The trusses 1 and strapping
wires 14 thus form a rigid cage which encloses and firmly holds the
low density core of blocks 11.
[0027] The longitudinal reinforcing wires 2 and 3 are preferably
inset by approximately one wire thickness from the bends in the
zig-zag wire 4, as shown in the enlarged inset detail of FIG. 2.
This enables a stronger joint to be formed since the longitudinal
wire 2, 3 can be welded at two points instead of one.
[0028] Once the caged core is in situ a cementitious and or plaster
render 15, 16 is sprayed or otherwise applied to the opposite side
faces of the core. The reinforcing wires 2, 3 and the strapping
wires 14 are encased within the render, acting as reinforcement for
the rendering layers. It is, however, important to note that in the
building panels according to the invention the cage structure has
sufficient strength and rigidity in its own right so that the
render is not necessary to add strength to the panels, and the
render layers can therefore be relatively thin.
[0029] By way of example, the wires forming the cage may be 2, 3 or
4 mm in diameter. The core blocks 11 may be at least 150 mm wide,
and could be up to 300 mm or more in width, with a typical
thickness (truss spacing) of 50 mm. The longitudinal reinforcing
wires 2 and 3 preferably project between 5 and 10 mm on both sides
of the core, encased within a render about 20 mm thick. The
strapping wires 14 are typically spaced at 50 mm intervals. It will
be appreciated however that the panels could be made to other
dimensions as required in any particular application.
[0030] The trusses are simple to manufacture by means of a machine
that forms one strand of wire into a zig-zag configuration, and
draws and straightens three further strands into contact with the
zig-zag wire. The wires are welded together at the points of
contact, and the trusses are cut to the required length.
[0031] The blocks and trusses are assembled, pressed together, and
the strapping wires are welded to the trusses in known manner.
[0032] For any given set of panel dimensions the trusses are
considerably stronger than known trusses of comparable dimensions,
which means that the wire diameter and weight can be reduced
without compromising the strength of the truss. The building panels
have significantly greater structural rigidity and load bearing
capability compared with known building panels of similar
construction. Zig-zag warren trusses have been criticised because
the welded trusses are sometimes under a certain amount of internal
tension, and the ends of the zig-zag wire might spring out when the
trusses are cut. Although this is not usually a problem, this
tendency is reduced in the present trusses since cut lengths of
wire spanning more than half the width of the truss are held by the
tie wire. Cut lengths less spanning less than half the width of the
truss do not normally move enough to be significant.
[0033] Where a still greater increase in strength (or truss width)
is required more than one longitudinally-extending tie wire can be
used. For example, the truss shown in FIG. 3 has two tie wires 5A
and 5B extending parallel to the reinforcing wires 2 and 3, again
both welded to the zig-zag wire 4. Such additional tie wires allow
further reduction in the wire diameter and/or increase in the
thickness of the building panel. The risk of springing movement of
cut ends of the zig-zag wire is reduced still further.
[0034] An alternative way of increasing the strength of the trusses
is illustrated in FIG. 4. Such an arrangement may be preferable in
trusses up to around 300 mm wide, although it can also be used for
wider or relatively narrow trusses. This form of the truss 1 again
has a pair of substantially parallel longitudinal reinforcing wires
2 and 3 with a tie wire 5C extending longitudinally substantially
mid-way between the wires 2 and 3. The wires 2 and 5 are joined by
a first zig-zag wire 4A which has its angular bends welded to both
wires, while the wires 5 and 3 are joined by a second zig-zag wire
4B which also has its angular bends welded to the alternate wires.
The truss thus forms a series of relatively small rigid triangles
and is thus much stronger and lighter than a known truss of the
same width. The truss just described could be modified to enable
the width to be increased still further with a relatively small
increase in weight. For example, further zig-zag wires and
longitudinal wires can be added to extend the width, typically up
to 450 mm or more. Also, as shown in FIG. 5, additional
longitudinally extending tie wires such as 5D and 5E can be fixed
along the intermediate portions of the zig-zag wires 4A and 4B.
[0035] In each form of truss it would be possible for the
intermediate tie wires of adjacent trusses to be connected together
during fabrication of the building panels by additional strapping
wires which are welded transversely to the tie wires, passing
between two adjacent low density blocks. Thus, the lightweight core
is more than one block wide.
[0036] If the free cut ends of the tie wires is perceived to be a
problem this can be eliminated by the method shown in FIG. 6. The
free end 5a of the tie wire 5 is bent angularly at its junction
with the transverse wire 4 and then welded or otherwise joined to
the adjacent reinforcing wire 3. This method is only suitable where
the length of the free end 5a is sufficient to meet one of the
reinforcing wires. An alternative arrangement is shown in FIG. 7,
where a bridging element 20 is welded between the reinforcing wires
2 and 3 at the end of the truss. The free cut ends of the
transverse wires 4 and tie wires 5 can each be welded to the
element 20, as shown. The element 20 may for example comprise a
flat metal strip, e.g. 2 mm.times.6 mm, a short length of wire,
etc.
[0037] Although it has been found that a straight tie wire provides
the greatest increase in strength for minimum increase in weight
and cost, the additional longitudinal wires need not necessarily be
straight. For example, as shown in FIG. 8, the use of two
transverse zig-zag wires 4C and 4D, preferably welded together at
their crossing points, will also increase the strength of the truss
without increasing wire thickness.
[0038] FIGS. 9 to 14 show another method of eliminating the free
cut ends of the tie wires in which the free end of a zig-zag wire 4
is bent angularly at its junction with one of the reinforcing wires
2 to extend perpendicularly across the truss. This end portion of
wire 4 is welded to the reinforcing wires 2 and 3 and the free cut
ends of any tie wires 5. These Figures also show that, for even
greater strength, various numbers of longitudinally-extending tie
wires 5C to 5E, with equal or unequal spacing, may be joined to the
zig-zag wire 4.
[0039] Whilst the above description places emphasis on the areas
which are believed to be new and addresses specific problems which
have been identified, it is intended that the features disclosed
herein may be used in any combination which is capable of providing
a new and useful advance in the art.
* * * * *