[0001] This invention relates to a wall tie, more particularly to a wall tie for use in
securing a wall to a parallel flange of a support member, for example a steel column
or wind post.
[0002] Wall ties are commonly used to secure brick or block built leaves of cavity walls
to one another or to secure walls constructed of building bricks or blocks to support
structures in order to strengthen the walls. One problem associated with wall ties
for securing walls to support structures is that the thickness and/or sectional shape
of the support structures is not uniform, and hence a variety of wall ties must be
provided so that the correct type of wall tie can be used at a particular location.
It is inconvenient to stock a large range of wall ties, and it is an object of the
invention to provide a wall tie in which this disadvantage is reduced.
[0003] According to the present invention there is provided a wall tie for use in securing
a wall to a support, the wall tie being characterized by a pair of limbs, each limb
carrying a respective jaw, the jaws being resiliently biased towards one another such
that, in use, the support is gripped therebetween, one of the limbs being arranged
to counter forces tending to move the wall away from the support, the other limb being
arranged to counter forces tending to move the wall towards the support.
[0004] The provision of resilient grip means allows a standard wall tie to be used in conjunction
with supports of varying thicknesses and section.
[0005] Preferably the wall tie is defined by a metal wire member in the form of a loop,
the ends of the member extending generally perpendicular to the length of the tie
adjacent one another and defining the first and second jaws respectively, the first
and second jaws preferably extending generally parallel to one another.
[0006] The loop is preferably of generally rectangular shape, the jaws being provided at
a first short side thereof. Each of the long sides of the loop is preferably shaped
so as to provide a point from which water can drip, in use.
[0007] Preferably, the side opposite said first short side is of length greater than said
first short side, the wire being smoothly curved at the junction of said side opposite
said first short side and a long side to displace part of the long side outwardly.
[0008] At least one of said jaws of the member is preferably reinforced. Such reinforcing
may be achieved by shaping the member so that the end region thereof doubles back
upon itself.
[0009] Preferably one end of the member defining one of the jaws is bent around that region
of the opposite long limb of the member which terminates in the other jaw, such that
said one jaw comprises a pair of parallel elements. Preferably said wire is stainless
steel; galvanised steel; or mild steel and may be provided within a plastics sleeve.
[0010] The invention will further be described, by way of example, with reference to the
accompanying drawings, in which:
Figure 1 is a perspective view of a wall tie according to a first embodiment of the
invention;
Figure 2 is a perspective view of a modification to the wall tie of Figure 1;
Figure 3 is a perspective view of a further modification;
Figure 4 is a perspective view of the embodiment of Figure 1, in use;
Figure 5 is a plan view of a second embodiment; and
Figure 6 is a cross-sectional view along the line X-X of Figure 5.
[0011] The wall tie illustrated in Figures 1 and 4 comprises a length of stainless steel
wire of 3.7 mm diameter shaped so as to form a generally planar rectangular loop 10,
the end regions 12, 14 of the length of wire overlapping generally parallel to each
other along a first short side 16 of the rectangular loop 10. The loop 10 has an opposite
short side 22 and generally parallel long sides 18 and 20, the end region 12 being
integral with the end of the long side 20 and extending perpendicular thereto.
[0012] The end region 12 of the wire is folded so as to double back upon itself to form
a U-shaped region through which the end of the long side 18 passes before becoming
the end region 14, the U-shaped region extending across the complete width of the
first short side 16.
[0013] The second end region 14 of the wire is also folded back upon itself, the folded
back wire also extending across the full width of the first short side 16 and also
extending along part of the length of a first long side 18 of the loop 10 through
the U-shape of the end region 12. Whereas the region 12 is an open U-shape, folded
back part of the region 14 is not open, the runs of the wire being in contact.
[0014] The second long side 20 extends generally parallel to the first long side 18, separated
therefrom by a distance generally equal to the length of the first short side 16.
The second short side 22 is longer than the first short side 16, the wire being smoothly
curved at the junction between the second short side 22 and the second long side 20
to displace part of the side 20 outwardly to allow for the increased length of the
second short side 22.
[0015] In use, during construction of a wall, the wall tie is attached to a support including
a flange 24 extending generally perpendicularly to the plane of the wall by inserting
the flange 24 between the ends 12, 14 of the wire. The flange 24 illustrated in Figure
4 is of generally rectangular cross section, the wall tie being suitable, by virtue
of its resilience, for use with supports including flanges of a variety of thicknesses
and a variety of cross sections, for example flanges of tapering cross section.
[0016] The action of attaching the wall tie to the flange 24 in this manner spreads the
end regions 12, 14 of the wire which act as cooperating jaws engaging opposite faces
of the flange, the resilience of the wire resulting in the flange 24 being gripped
therebetween. The other end of the wall tie is embedded in the mortar of the wall
before an upper course of building bricks or blocks is positioned thereon.
[0017] It will be understood that once the mortar has set, forces tending to move the wall
towards the support result in the limb of the wall tie including the second long side
20 experiencing a compressive load which is transmitted to the support by means of
the first end region 12 of the member, and forces tending to move the wall away from
the support result in the limb of the wall tie including the first long side 18 being
put under tension, this force being transmitted to the support through the second
end region 14 of the member.
[0018] The embodiments shown in Figures 2 and 3 are modifications of the embodiment described
above. The first and second ends 12, 14 of the embodiment shown in Figure 2 are not
folded back upon themselves, this construction being a very simple construction. This
construction is particularly suitable for use where the loading to be applied to the
wall tie is likely to be small. It has been found that when larger loads are applied
to the wall tie the loop may tend to buckle allowing the jaws 12, 14 to slide off
the flange. The use of a U-shape for the jaw or end region 12 with the long side 18
extending therethrough effects a restraining action resisting such buckling and moreover
spreads compressive loadings over a greater area of the flange further stabilizing
the tie. The reinforcement of the jaw 14 by folding back (Figures 1 and 4) increases
the resistance of the jaw 14 to straightening when the long side 18 is in tension.
[0019] The wall ties illustrated in Figures 2 and 3 are used in exactly the same manner
as that illustrated in Figures 1 and 4.
[0020] In each of the illustrated wall ties the long sides 18, 20 are preferably provided,
at a point which will lie in the cavity between the wall and the flange 24, with a
downward kink to provide a drip formation for promoting the collection and shedding
of water drops in known manner.
[0021] The support including the flange 24 can be any of a variety of known structures including
a steel column of H or I section, a channel member, an angle section and various known
wind post constructions.
[0022] The embodiment illustrated in Figures 5 and 6 is similar to the first embodiment
and the modifications thereto described above, and like reference numerals in the
following description will be used to denote parts similar to those of the first embodiment
and the described modifications.
[0023] The wall tie of Figures 5 and 6 comprises a length of 4.85 mm diameter stainless
steel wire bent so as to form a generally rectangular loop 10, the end regions 12,
14 of the wire overlapping one another at the corner between a short side 16 and a
long side 20 of the loop 10. The loop 10 has a second long side 18 parallel to the
side 20, the ends of the long sides 18, 20 furthest from the end regions 12, 14 being
interconnected by an integral part circular region 26 of diameter greater than the
separation of the long sides 18, 20. A downwardly directed kink 34 is provided in
each of the long sides 18, 20 to define a pair of points at which water collects and
from which water drips in order to prevent the flow of water along the full length
of the long sides 18, 20. The kink 34 is shown clearly in Figure 6.
[0024] The end region 12 is folded back upon itself defining a generally U-shaped region,
the long side 20 extending between the arms of the U-shaped region.
[0025] The end region 14 is shaped so as to include a first region 28 at the free end thereof
extending generally parallel to the end region 12, a second region 30 extending away
from the end region 12, and a third, curved region 32 at the junction between the
end region 14 of the long side 20.
[0026] In use, the wall tie is attached to the support structure of the construction by
introducing part of the support structure between the end region 12 and the first
region 28 of the end region 14, these regions of the wall tie being resiliently biased
towards one another to grip the support structure. The part circular region 26 together
with the ends of the long sides 18, 20 is positioned in the mortar on top of a course
of bricks or other building blocks, and a further course of bricks or blocks are positioned
on top of the mortar. Once the mortar has hardened, the wall tie acts to prevent movement
of the leaf wall constructed of bricks or blocks towards or away from the support
structure, movement of the leaf away from the support structure being countered by
the long side 20 becoming under tension whilst movement of the leaf towards the support
structure is countered by the long side 18 being compressed.
It has been found that when the long side 18 is compressed, there is a tendency for
the long side 18 to flex away from the long side 20 and in this embodiment, such flexing
is restricted by the end region 12 being bent around the long side 20. When the long
side 20 becomes under tension, there is a tendency for the end region 14 to bend towards
the axis of the long side 20, and the provision of the second and third regions 30,
32 of the end region 14 in this embodiment tends to reduce such bending.
[0027] In the second embodiment, the second region 30 of the end region 14 extends generally
parallel to the long side 20. It is envisaged that the second region 30 may extend
away from the end region 12 at an angle of approximately 30°, and that the end region
14 of the wall tie of the first embodiment and its modification may also be provided
with the above described first, second and third regions 28, 30, 32. In addition,
such embodiments may also be provided with the part circular region 26 interconnecting
the long sides 18, 20 instead of the second short side described above.
1. A wall tie for use in securing a wall to a support, the wall tie being characterized
by a pair of limbs (18, 20), each limb (18, 20) carrying a respective jaw (12, 14),
the jaws (12, 14) being resiliently biased towards one another such that, in use,
the support is gripped therebetween, one of the limbs (18) being arranged to counter
forces tending to move the wall away from the support, the other limb (20) being arranged
to counter forces tending to move the wall towards the support.
2. A wall tie as claimed in Claim 1, characterized in that the wall tie is defined by
a metal wire member in the form of a loop (10), the ends of the member extending generally
perpendicular to the length of the tie adjacent one another and defining the first
and second jaws (12, 14) respectively.
3. A wall tie as claimed in Claim 2, characterized in that the first and second jaws
extend generally parallel to one another.
4. A wall tie as claimed in Claim 2 or Claim 3, characterized in that the loop is of
generally rectangular shape, the jaws (12, 14) being provided at a first short side
(16) thereof.
5. A wall tie as claimed in Claim 4, wherein the side opposite said first short side
(16) is of length greater than said first short side (16), the wire being smoothly
curved at the junction of said side opposite said first short side (16) and a long
side (20) to displace part of the long side (20) outwardly.
6. A wall tie as claimed in Claim 2 or Claim 3, wherein the part of the loop opposite
said first and second jaws (12, 14) is of part circular form.
7. A wall tie as claimed in Claim 4, 5 or 6, characterized in that each of the long sides
(18, 20) of the loop (10) is shaped so as to provide a point from which water can
drip, in use.
8. A wall tie as claimed in any one of Claims 1 to 7, characterized in that at least
one of said jaws (12, 14) is reinforced.
9. A wall tie as claimed in Claim 8, characterized in that the at least one jaw (12,
14) is reinforced by shaping the member so that the end region thereof doubles back
upon itself.
10. A wall tie as claimed in any one of Claims 1 to 9, characterized in that the end of
the member defining one of the jaws (12) is bent around that region of the opposite
limb of the member which terminates in the other jaw (14), such that said one jaw
(12) comprises a pair of parallel elements.
11. A wall tie as claimed in any one of the preceding claims, characterized in that the
end of the member defining one of the jaws (14) comprises a first region (28) extending
generally parallel to the other jaw (12), and a second region (30) extend away from
said other jaw (12).