Note: Descriptions are shown in the official language in which they were submitted.
WALL-TIES
TECHNICAL FIELD OF ~E INVENTION
The invention relates to wall-ties, which are generally used to tie
together spaced apart skins of multi-skin walls.
BACKGROUND ART
Wall-ties are often used to tie together the skir~s of a multi-.skin
cavity wall. When such a wall is built, one skin is built up to a
required height with the wall-ties projecting from it into the
cavity to be joined. The bricklayer then builds up the adjacent
skin to form the cavity, at the same time incorporating the end of
the wall-tie which is to be incorporated therein in that skin, so
tying the skins together with part of the wall-tie spanning the
cavity. ~he problem is that the projecting part can, before it is
incorporated in the second skin, present a hazard as the end is
sharp and can injure a bricklayer. Further, with the advent of the
use of irLsulation in a cavity, part of the width of which is filled
with such insulation, means of the wall-tie for collecting moisture
can be covered up so that the wall tie forms a bridge for moisture
so possibly damaging the wall.
. DISCLOSURE OF INVENTION
It is an object of the invention to seek to mitigate these
disadvantages of prior wall-ties.
According to one aspect of the invention there is provided a wall-
tie for a multi-skin cavity wall, comprising, for anchorage with one
skin of the wall, a substantially planar limb having a free end,
wherein the free end has a curved part which extends out of the
plane of the limb to provide a substantially ~mooth external
surface. i~
.
~:2~
-- 2 --
The expression "curved" is defined herein to include an effective
curve, that is one which is made up of a plurality of differently
irclined planar parts which are integrally connected together in
sequence to form what is an effect a curve.
The curved part may lead to an inclined part which may overlie the
limb. Using this construction sharp en~s of the wall-tie are
avoided.
The inclined part may be inclined at substantially 90 to the plane
of the limh.
The curved part may comprise a roll lip. This provides a relatively
simple construction which avoids the forming of a sharp free edge of
the limb of the wa]l tie.
The roll lip may comprise two separate roll lip parts, as considered
transversely of the limb, separated by a notch, cut-out, slot or the
like. This construction provides a method of forming the wall-tie
by mass production.
f
The free end(s) of the roll lip or roll lip parts may touch the
limb. This erables the roll lip to be substantially circular in
cross-section with the free el~ effectively hidden so that there is
ro sharp edge.
The free end of the limb may extend in a curve from one side of the
limb to the other, as considered in the plane of the limb.
The lateral edges of the limh may be inclined, preferably at an
angle of substantially 90O, to the plane of the limb. This provides
limb(s) in which sharp edges are avoided.
According to a second aspect of the invention there is provided a
wall-tie for a m~lti-skin cavity wall, comprising a limb for
anchorage with a first skin of the wall~ another limb for anchorage
3~
- 3 -
with a second skin of the wall adjacent the first skin of the wall,
at least one of the limbs having means for enhancing the anchorage
of that limb hith a skin of the multi-skin wall, connecting mea~s
for connecting the limbs comprising a depres.sion or channel for
.stiffening at least a portion of the wall-tie a~d means for
preventing or hindering moisture transfer across said wall-t.ie
comprising a lip located adjacent one side of the depression or
channel and another lip located adjacent the opposite side of the
depression, each lip having at least one mea~s where water can
collect when the lips are pointing in a generally downward
direction, each limb being substantially planar and at least the
free end of one limb having a curved part which extends out of the
plane of the limb to provide a sub.stantially smooth external
surface.
~here may be a plurality of cut out or struck out portions of the
lip; preferably there may be three such portions spaced apart along
the length of each lip. This construction is such that in use there
will always generally be a lip free of insulating material in a
cavity when such insulating material is incorporated in the multi-
skin wal~l.
me wall-ties may be made of metal, preferably stainless steel. Use
of stairless steel obviates corrosion and er~ances the life of the
wall-tie and hence that of the wall.
According to a third aspect of the invention there is provided a
method of making a wall-tie as hereinbefore defined, comprising the
steps of forming a substantially plarlar limb of the wall tie,
forming a notch, cut-out, slot, slit or the like in a free end of
the limh, and forming a roll lip by deforming the material of the
wall-tie on each side of the notch, cut-out, slot, slit or the like
into a roll lip part .so that the free end of the wall tie has a
curved part which extends out of the plane of the limb to provide a
; su~stantially smooth external surface.
-- 4 --
The roll lip parts may be progressively formed to provide the roll
lip.
Wall-ties embodying the invention are hereinafter described, by way
of example, with reference to the accom.oanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a plan view of a wall-tie according to the in~ention;
Fig. 2 is a side elevational view of the wall-tie of Fig. 1 sho~ing
it, schematically, in position in a cavity w~ll
Fig. 3 is an el~arged view of a free end of a limb of the wall-tie
of Figs. 1 and 2.
Fig. 4 is an enlarged plan view of a free end of a limb of a second
wall tie embodying the invention-and
Fig. S is a cross-sectional view of the end shown in Fig. 4, taken
along line 'A'-'A'.
Referring firstly to Figs. 1,2 and 3 of the drawings the wa~l-tie 1
shown is made from stainless steel and has a limb 2 for anchorage in
one skin 3 of a multi-skin wall and another limb 4 for anchorage in
another skin 5 of the cavity wall which is parallel to and adjacent
the first skin 3 and spaced therefrom by a cavity 6 (Fig. 2). Both
limbs 2 and 4 have means for enhancing anchorage in the re.spective
skin in the form of upwardly (as considered in use and as shown in
Fig. 2) inclined tabs which are semi-circular and are struck out of
the limbs. There are five such tabs 7 in each limb 2 and 4.
The free ends 8 of each limb 2 and 4 each have a curved part 8'
which extends out of the plane of the limb 2,4 to provide a
; substantially smooth surface. In Figs. 1,2 and 3, the free ends 8
are upwardly inclined~ from the curved part 8' about the same height
'
-- 5 --
as the tabs 7, and terminate inboard of the free ends of the limbs 2
and 4. The free en~s are inclined at about 25 to the respective
limbs 2 and 4 which are generally planar.
The limbs 2 and 4 are connected by connecting means 9 in the form of
S a downwardly open (as considered in ~se and in Fi~s. 1 and 2)
elongate depression or channel 10 which extends from one li~b 2 to
the other 4 and is raised out of the plane of the ~co-planar) limbs
and rises to an apex 11, the depression or channel 10 being flanked
by incurved and downwardly extending lips 12 each of which has means
in the form of three spaced semi-circular cut-out or struck out
portions 13 in its lowermost edge, each portion 13 providing points
14 at which moisture can condense and collect, and hence from which
it can drip off the wall tie 1 in the cavity 6 as drops, so that
passage of moisture across the cavity via the wall tie from one skin
3 to the oth~r 5 is prevented or hindered.
In use, the wall tie 1 is mounted by anchoring say the limb 2 in the
skin 3 if that skin 3 is being built up first. The wall tie 1 is
embedded up to the connecting means 9 as shown by the dashed line
15, the surface of the skin 3. T~e tabs 7 e~ihance anchorage by
becoming embedded in mortar between courses of bricks, blocks etc of
the skin 3. The mortar also passes through the holes in the limb 2
left behind when the tabs 7 are struck out. Also, the upturned free
end 8 acts as an additional anchorage. Ihe upturned free end 8 of
the protruding limb 4 being inclined to the plane of the limb 4,
; 25 presents the relatively .smooth, non-sharp curved part 8'which does
rot have a sharp edge externally (as considered of the wall-tie)
edge so that a bricklayer or other workman is not likely to be
injured should he snag himself on the protruding free end in the
course of his work. The free limb 4 is entirely embedded in the
skin 5 when that skin 5 is erected to complete the cavity wall, the
connecting means 9 being exposed in the cavity 6, the wall tie 1
tying the two skins together. The relatively narrow nature of the
connecting means 9 as compared to the width of the limbs 2 and 3
means that there is a relatively small surface area for collection
i ''`' ~ .
of mortar falling from higher up the wall as it is raised. The
falling m~rtar as it strikes the wall tie 1 tends to slide off, to
the bottom of the wall. Thus "bridging" is avoided in other words no
build up occurs of a deposit of mortar which spans the cavity and
provides a path for moisture fron the outer to the inner skin.
Likewise any moisture condensing on the wall tie 1 is encouraged to
run downwards towards the cut out or struck out portions 13 because
the only path is downwar~s as shown, from the central raised peak or
apex 11 the sides of the channel or depression 10 merging smoothly
with the inwardly curved lips 12 which in turn lead to the portions
13 where the moisture collects and forms drops which eventually drop
off into the cavity 6, from the points 14.
If insulating material 16 is used in the cavity, as shown by chain-
dashed lines, -that material ~6 does not fill the cavity 6 between
the skins 3 and 5 because it would form a bridge for moisture. It
stops short of one skin, as shown (Fig. 2~. However, when in
position it tends to ma~sk some of the cut-out or struck out portions
13, but as there is a plurality of those portions, there is always
at least one which is free of insulating material and is thus
exposed for collection of moisture and preventing passage of the
moisture across the cavity.
Referring now to Figs. 4 and 5 there is shown therein part of a
second embodi~ment of wall-tie 20 embodying the invention. The wall-
tie 20 is similar to the wall tie 1 in that it has co-planar limbs
(of which one 21 is shown) both having means, for enhancing
anchorage in skins of a multi-cavity wall, in the fo~m of upwardly
inclined tabs (not shown) which are semi-circular and are struck out
of the limbs and are like the tabs 7 previously described with
reference to Figs. 1 to 3. The limbs are connected by cormecting
means like the means 9 previously described with reference to Figs 1
to 3, so details thereof are omitted for clarity, Figs. 4 and 5
showing the free end of the limb 21.
The limb 21, which is substantially planar, has a free end havi~g a
,
~23
-- 7 --
curved part 22 which extends out if the plane of the limb 21 to
provide a ~ub.stantially sm~oth external surface, ('external' meaning
externally of the wall tie, in a direction that i6 opposite the
other limb of the wall-tie 20). The curved part compri.ses a
S substantially circular roll lip formed of roll lip pa~ts 23 and 24
separated by a slot 25. The roll lip parts 23 and 24 are formed so
that the free ends 26 thereof contact the limb and are thus "hidden"
under the main body of the respective roll lip part 23 or 24 (as
cor~sidered from above (Fig. 5) so that no free or sharp edges are
present. Thus there is no free or sharp edge present to snag or
catch on and thus possibly to injure a bricklayer or other workman
should he snag himself on the protruding free end in the course of
his work. (The wall-tie 20 is used in a similar manner to the use of
the wall-tie 1, previously described).
The free end of the limb 21 is rounded or radiused as shown (Fig. 4)
to provide a smooth, continuous curve in the plane of the wall tie,
from one lateral edge to the other. This makes it easier to form the
roll-lip parts 23 and 24 and to fold them.
The wall-ties l and 20 above described and shown in the drawings may
be modified. For example, the lateral edges of each limb 2 and 4 may
be inclined to the plane of the limbs, for example they may be
turned upwardly through an angle of substantially 90 . This
construction, like the smooth ends 8', 22 provides for ease of
handling by avoiding sharp exposed edges.
There may also be more or fewer tabs 7 than the five shown in each
limb.
The wall-ties may be stamped out of a strip of metal preferably
stainless steel in a continuous automatic process, the length of the
wall tie being equivalent to the width of the strip of metal. The
wall tie 20 is made by such an automatic process, the free end of
each limb 21 being rounded, the notch, cut-out or slot, slit or the
like 25 being fonmed centrally in the parent metal of the wall tie,
~3
- 8 -
and th~ material on each side of the slot being ~ub.sequently
automatically pro~essively bent or folded to provide. the
substantislly circular roll lip parts shown, and hence the curved
part 22 with the smooth external surface.
The wall ties described are used in brick-cavity-brick multi-skin
wall constructions. If the limbs are di.spo.sed at substantially 90~
the wall ties can be used for timber-cavity-brick multi-skin wall
constructio~sO (It will be understood that the term "brick" includes
breeze blocks, st~ne slabs and other similar building units~.
