Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FIF.LD OF INVENTION
This invention relates to a device for supporting
a pair of reinforcing bars, each at a different
predetermined distance from an underlying surface.
BACKGROUND
When a reinforced concrete floor or like structure
is being poured, it is frequently necessary to support two
layers of reinforcing bars at different depths in the
concrete which is being poured. The reinforcing bars of the
lower layer are supported a first distance above the
underlying surface. The reinforcing bars of the upper layer
are supported a second distance above the underlying surface
so as to be a given distance below the surface of the poured
concrete.
The first and second distances will depend on a
number of factors and may vary not only from installation to
installation but also at different locations in the same
installation and even in thge same concrete floor.
A number of devices have been devised for
supporting reinforcing bars at the desired heights. Some of
these devices only provide support at one height, in which
case two devices would be needed to support two layers of
reinforcing bars at different heights. Others of these
devices can support two reinforcing bars, each at a
different height.
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Some of the prior supporting devices which support
one layer of reinforcing bars are generally circular in plan
and have recesses of different depths in their opposed
faces. These can support reinforcing bars at only two
different but closely spaced levels. Others of those
devices additionally have recesses of different depths
running in different directions across each end face. By
varying the orientation of these devices it is possible to
vary the height at which they support a single layer of
reinforcing rods. However, they are unstable. In addition,
while these devices have the advantage of being able to
provide various heights of support using one device, as they
can only support one layer of reinforcing bars, a second set
of such devices is required to support a second layer of
reinforcing bars. This requires a significantly greater
number of such supporting devices than would be required if
each device would support two reinforcing bars at different
heights.
A previous device which can support two layers of
reinforcing bars at different heights comprises a base
portion having a first height and a generally inverted
U-shaped upper portion, the opposed ends of which are
insertable into recesses formed in the base portion. In
use, one reinforcing bar is placed on the base portion at
the first height, the U-shaped portion is then mounted over
the first reinforcing bar and the opposed ends of the
U-shaped portion inserted into the recesses in the base
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portion. A second reinforcing bar is then placed on the
transverse part of the U-shaped portion at a second height
and located thereon by a suitably shaped recess formed in
the U-shaped portion. While this latter device can support
two reinforcing bars at different heights, neither of the
two heights is variable. Accordingly, different base
portions and U-shaped portions are required for each
different height desired. In addition, forming the U-shaped
portion with its recess is costly.
BRIEF SUMMARY OF INVENTION
Accordingly, it is an object of the present
invention to provide a device for supporting reinforcing
bars which is both versatile and inexpensive. In one of its
aspects, the present invention provides a device for
supporting reinforcing bars comprising:
a plurality of legs having inner ends, said inner
ends beiny joined together at a generally central location,
said legs extending radially outwardly in different
directions and each leg terminating in an outer free end,
each leg having an upper surface, each upper surface having
a recess therein for receiving and supporting a reinforcing
bar, each recess being located at a different height from
that of the other recesses, so that said device may support
a reinforcing bar at different heights depending on which
leg said reinforcing bar is placed.
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Further objects and advantages of the invention
will appear from the following description, taken together
with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is an isometric view of a reinforcing bar
support according to the present invention; and
Figure 2 is an isometric view of a modified
reinforcing bar support according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Reference is first made to Figure 1, which shows a
reinforcing bar support according to the invention and
identified generally at 10. The reinforcing bar support 10
has a lower supporting member 12 and an upper supporting
member 14.
lS The lower supporting member 12 has a generally
upright central cylindrical column 16 definingg a vertical
first socket 18. This socket 18 has an upper opening 20, as
shown, and is closed at its bottom end. Three generally
rectangular legs, 22, 24, and 26 have inner ends joined to
the column 16 and extend generally radially away in
different directions from the column 16. The legs 22, 24 and
26 terminate in free outer ends 22a, 24a, 26a and have lower
surfaces 28, 30 and 32 respectively, which have their
lowermost portions located in a common plane. The surfaces
28, 30, 32 therefore form a base which supports the device
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on a supporting surface such as a sheet of plywood on which
the concrete is to be poured. The socket 18 has an axis 17
generally perpendicular to the plane of such supporting
surface.
The legs 22, 24 and 26 have respective concave or
U-shaped recesses, 34, 36 and 38 extending across their
upper surfaces. The lowermost portions of the recesses, 34,
36 and 38 differ in vertical height above the coplanar lower
surfaces 28, 30 and 32 of the legs 22, 24 and 26.
The upper supporting member 14 has a generally
cylindrical second socket 40 depending from a head 42. The
head 42 has a generally U-shaped channel 44 extending across
its upper surface. The second socket 40 has an opening 46
at its lower end, so that the channel 44 and the opening 46
lS face in opposite directions. The second socket 40 has an
axis 48. The channel has an axis 50 running therealong. The
axes 48 and 50 are generally perpendicular.
The first and second sockets, 16 and 40
respectively, are sized so as to be capable of receiving
opposite ends 62 and 64 of a vertical spacing rod 60
extending therebetween. As shown in Figure 1, the ]ower
supporting member 12 is supported on its base. The lower
supporting member 12 in turn supports the spacing rod 60 in
the first socket 16. The spacing rod 60 in turn engages the
second socket 40 of the upper supporting member 14 to
support the upper supporting member 14 above the lower
supporting member 12.
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In use, the base of the lower supporting member is
placed on a surface and a reinforcing bar shown in dotted
lines at 70 is placed in one of the recesses 34, 36 or 38.
The recesses are suitably contoured to receive the side of
reinforcing bar. The lower supporting member supports the
lower layer of reinforcing bars. The height of the
reinforcing bar 70 above the underlying surface, is
determined by selecting the appropriate one of the recesses
34, 36 and 38. The reinforcing bar 70 forms part of the
lower layer of reinforcing bars. If the lower layer
consists of two sets of reinforcing bars at right angles to
each other, another reinforcing bar shown in dotted lines at
72 can be laid on top of reinforcing bar 70.
Next, one end 64 of a spacing rod 60 of a suitable
length is inserted into the opening 18 of socket 16. The
socket 40 of the upper supporting member 14 is then mounted
on the end 62 of the spacing rod 60 and another reinforcing
bar (not shown) is placed in the channel 44 to extend
thereacross. The channel 44 is suitably shaped to receive
the side of the second reinforcing bar. The upper
supporting member 14 therefore supports a bar from the upper
layer of reinforcing bars.
It will be seen that the height of the upper
supporting member 14 above the surface underlying the lower
supporting member 12 is determined by the length of the
spacing rod 60. Accordingly, by selecting spacing rods 60
of different lengths and selecting different ones of the
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7 --
recesses 34, 36 and 38 in the lower supporting member 12,
the reinforcing bar support 10 can support each of two
layers of reinforcing bars at various heights. This of
course reduces the inventory of reinforcing bar supports
that needs to be carried and reduces tooling costs as the
upper and lower supporting members can be common to a
variety of applications. Furthermore, if reinforcing bar
supports are left over from one job site, there is a much
greater likelihood that these will turn out to be useful on
the next job site.
To further minimize cost and the number of pieces
which need to be inventoried, it is preferred, as shown in
Figure 1, that the spacing rod 60 be cut from a reinforcing
bar and that the first and second sockets 16 and 40 be sized
to receive such a bar. As most construction projects
typically have odds and ends of reinforcing bars readily
available, spacing bars 60 of suitable height can be cut
from these locally on the job site or at any convenient
location. Bar of diameter 10 mm or 3/8 inch diameter may
typically be used for rod 60.
Various materials can be used -to form -the
reinforcing bar support 10. Preferably, the upper and lower
supporting members 14 and 12 respectively, are moulded from
plastic. Alternatively, these pieces can be manufactured
from steel plate and tubing cut to appropriate shapes and
welded together.
The legs 22, 24 and 26 of the lower supporting
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member 12 can be provided with respective openings 75, 76
and 77 through which a wire can be passed to secure the
reinforcing bar to the legs. The openings 75, 76 and 77
also permit concrete to pass through the legs to firmly
embed the lower supporting member 12 in the concrete and to
reduce the likelihood of voids in the concrete surrounding
the lower supporting member 12.
As shown in Figure 1, the lower surface 28 has a
recess 78 formed therein. The recess 78 is provided so that
if desired, a supporting member 12 can be turned upside down
and used in place of the upper supporting member 14. This
may typically occur on small jobs where a worker has a box
of members 12 and no members 14. When member 12 is used
upside down as an upper support, a reinforcing bar is simply
placed in the recess 78.
It will be appreciated that what has been
described is a preferred embodiment of the invention and
that variations may be apparent to those skilled in the art
both to the materials and structure of the present
invention, while staying within the spirit and scope of what
is claimed.
For example, the base can be a separate,
disc-shaped or rectangular element attaching to the ends 28,
30 and 32. Such an arrangemen-t might be desirable to add
stability if, for example, only two legs were used or if it
were desired not to attach the legs directly to the socket
16. Further, the lower surfaces 28, 20 and 32 of the legs
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22, 24 and 26 respectively may define a base without the
bottom end of socket 16 extending to the plane of the base.
In addition, and as shown in Figure 2, where primed
reference numerals indicate parts corresponding to those at
Figure 1, the lower end of socket 16' may be attached to a
flat base 80 of suitable si~e to provide good stability and
the legs 22', 24' and 26' may extend radially from the first
socket 16' with their respective lower surfaces 28', 30' and
32' being above the base 80. However, the Figure 2 version
is less desirable than the Figure 1 version, e.g. because
the legs 22', 24', 26' would have to be made of very strong
material to support the reinforcing bars, and because base
80 must be wide enough to avoid tipping.
Although three legs have been shown, there could
be four or five legs if desired.
In some cases, only a single layer of reinforcing
bars will be needed, and in that case upper member 14 will
not be used. In that case the socket in central column 16
can be omitted, or the column 16 itself can be omitted and
the legs joined directly to each other. However, the colurnn
16 and its socket are preferred.
