Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~3027Z5
A REINFORCING ROD HOLDER FOR USE IN JOINING
CAST CONCRETE WORK
The present invention relates to a reinforcing rod
holder for use in joining cast concrete work, comprising a
hollow body in which may be disposed the free, bent ends of
the reinforcing rods.
Such a reinforcing rod holder is known, for example,
from CH-A-627 811, wherein its hollow body is formed from a
front portion and a cover portion, and this holder is mainly
produced from plastics material. In the last few years,
the use of industrially manufactured reinforcing rod holders
which have already been equipped before leaving the factory
has increased very considerably, and a large number of
extremely varied reinforcing rod holders have been designed
and used. During the course of ever wider applications and
ever greater attempts at rationalisation, it has become - -
apparent that ever greater slgnificance is attributed to the
thorough and rapid removal of the holder or portions thereof.
This was initially taken into consideration, on the one hand,
by replacing the reinforcing rod holders, which were
originally formed only from expanded plastics material, by
hollow bodies formed from plastics material, thereby
substantially facilitating removal. However, it is possible
that these bodies formed from plastics material might break
during removal and thereby involve additional work. On the
other hand, there are reinforcing rod holders which are formed
from metal or expanded metal and which remain in the wall
after being embedded in concrete, so that it is only necessary
to remove portions thereof, generally the cover portion.
Reinforcing rod holders which are substantially formed only
from metal are relatively expensive and, in addition, an
increasing number of countries are inclined to issue
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2 23444-268
regulations whereby metal portions have to be covered with a layer
of concrete of specified thickness, for example 25 mm.
By way of contrast, the present invention seeks to
provide a reinforcing rod holder which is lighweight in respect of
its component parts, is transportable, and can be rapidly and
easily assembled, the free ends of the reinforcing rods being well
secured in the holder and being well protected from the
possibility of liquid cement penetrating therein. Further it is
sought to provide a holder which is much easier to remove,
especially when compared with holders formed from plastics
material or expanded material, and it is more economical both in
terms of manufacture and in respect of the portion remaining in
the erected wall, than reinforcing rod holders which are
substantially formed from metal.
According to the invention the reinforcing rod holder
comprises a hollow body in which may be disposed the free, bent
ends of reinforcing rods, wherein the hollow body is formed from a
box-shaped portion and a cover portion which comprises a metal
plate and for facing a concrete wall to be erected, the cover
portion being adapted to remain in the erected concrete wall.
Therefore this invention seeks to provide a reinforcing
rod holder for use in joining cast concrete work comprising: a
box-shaped body adapted to receive free ends of reinforcing rods;
a cover means removably secured to said body, for substantially
enclosing said body; and an embedding means for embedding said
cover means in a concrete mass, apart from said body, while said
cover means is removably secured to said body, said embedding
means comprising a recess means formed in said box-shaped body for
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2a 23444-268
permitting concrete to pass behind said cover means when the
holder is embedded in concrete.
The invention is explained more fully hereinafter with
reference to the following drawings.
Fig. 1 is a view, from above, of a first e~bodiment of a
reinforcing rod holder according to the invention, part of which
is shown without the cover portion.
Fig. 2 is a sectional view taken along the line II-II.
Fig. 3 shows a detail of Fig. 2 after the cover portion
has been fitted.
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Fig. 4 is a sectional view taken along the line
IV-IY of Fig. 1.
Fig. 5 is a sectional view taken along the line V-V
of Fig. 1.
Fig. 6 is an enlarged detail of a modified embodiment
of the cover portion.
Fig. 7 is a view, from above, of a second embodiment
of a reinforcing rod holder, part of which is shown without
the cover portion.
Fig. 8 is a sectional view, taken along the line
VIII-VIII of Fig. 7, of a modified embodiment of the cover
portion.
Fig. 9 is a sectional view taken along the line
IX-IX of Fig. 7.
Fig. 10 is a view, from above9 of a third embodiment
of a reinforcing rod holder, part of which is shown without
the cover portlon.
Fig. ll is a sectional ~iew taken along the line
XI-XI of Fig. 10.
Fig. 12 is a sectional view of the reinforcing rod
hoIder shown in Fig. 1, prior to its being embedded in concrete.
; Fig. 13 illustrates a reinforcing rod with the remaining
cover portion after being embedded in concrete.
The first embodiment of a reinforcing rod holder includes
a box 1, which is formed from plastics material, and a cover
portion 2 at the wall end which is formed from metal and
remains in the wall after the reinforcing rod holder has
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been embedded in concrete. The cover portion remaining
in the erected wall 55 is formed from only one plate which,
on the one hand, is relatively simple to manufacture and,
on the other hand, has smaller dimensions than hitherto-known
portions of reinforcing holders which are formed from metal
and are intended to remain in the erected wall.
The box 1 is provided with a circumferential, double,
U-shaped edge 3 having an inner wall 4 and an outer wall 5.
The outer wall 5 has indentations 6 which are distributed
around the entire outer wall. When the reinforing rod holder
is embedded in concrete, these indentations 6 cause concrete
to pass behind the cover portion plate 2 which is to remain
behind, so that this plate is securely joined to the wall and
cannot become loosened, even when the rods are straightened
and the plastics portion of the holder is removed. Pins 7
are provided on the upper surface of the circumferential edge
and, as can be seen from fig. 2, they extend through corres-
ponding openings 8 in the cover portion and are compressed,
see Fig. 3, by means of a suitable device in such a manner
that they press and secure the cover portion onto the box.
Raised portions 10, which are disposed in the centre of the
box base 9 and protrude therefrom, serve the same purpose,
and they also have pins 7 which fit into the corresponding
openings 8 in the cover portion and are compressed. Each
of the edges on the longitudinal sides is provided with a
cover bar 11 which has, on its outer surface, recesses 12
whiCh correspond to the indentations 6 and recesses 13 for
exposing the pins 7. At the locations where the reinforcing
rods 14 protrude from the box and cover portion, sockets 15
are provided in the cover bar 11 and extend through corres-
ponding openings 16 in the cover portion. The sockets 15
taper upwardly and have, at their upper end, a hole 17 through
which reinforcing rods are inserted. To permit the
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reinforcing rod to be inserted into the sockets, the
inwardly orientated portion 18 of the cover bar and the inner
surface of the socket 15 have a slot 19, as can be seen from
Fig. 4. Instead of being extruded from plastics material as
three component parts, the box and the two cover bars and the
sockets can be extruded from plastics material in one piece.
To permit insertion of the rods, in this case, it is necessary
for the entire box to be supported around is longitudinal
central axis. The reinforcing rods 14 are bent in a
conventional manner so that the free ends converge with respect
to the longitudinal central axis of the box. As can be seen
from Fig. 5, in particular, the sockets permit the entire
rounded portion, i.e. the transitional area between the clamp
portion and the free ends of the reinforcing rod, to be
situated within the holder. This arrangement ensures that
the reinforcing rod can be fully straightened after removal
of the plastics box and the sockets, as shown in Fig. 13.
As already mentioned above, the cover portion 2 is
formed from metal. Since this cover portion remains in the
wall, it is advantageous for as good a join as possible to
be established between this metal portion and the wall. For
this reason, it is deslrable to provide the cover portion with
a rough surface; this may be effected, for example, while the
cover portion is being produced from expanded metal or, as
shown in Fig. 6, by providing the cover portion with stamped
and relatively sharp-edged raised portions 20. Other steps
may also be taken, however, to increase the roughness of the
surface.
In certain countries, there are regulations stipul-
ating that unprotected metal, i.e. metal which is not rust-
proof, must be covered with aminimum layer of concrete, for
example. 25 mm. This would signify that the metal plate must
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have the prescrihed minimum spacing from one edge. To permit
the metal plate to be moved nearer the edge, it is extremely
desirable with such regulations to protect the metal either by
applying a layer of plastics material or by spraying with
other resistant materials, for example, by means of electro-
, static powder coating or the like. It is clear, therefore,
j that only the outer edge of the cover portion needs to be
i coated and not the entire metal plate.
j 10 In the described example, the box 1 is formed from afilm of plastics material with a double, U-shaped edge. The
plastics material may be replaced by another material; thus,
I for example, a strong cardboard may also be used, and it isI not necessary for the edge to be formed from two walls which
! 15 are joined together in a U-shaped manner. It is also
possible for the connection between the box portion and the
cover portion to be effected in a manner other than by means
of expanding pins. It is also possible, for example, to
~oin the two portions together by means of spot-welding or
; 20 glueing, or to use other suitable securing means. In this
i embodiment, it may also prove appropriate to construct the
metal plate in a multi-component manner so that, for example,
' it may be divided along the central axis.
Figures 7 to 9 illustrate a second embodiment of a
reinforcing rod holder, whereby both the manufacture and the
assembly of the reinforcing rod holder are an improvement over
the first embodiment. Box 1 is the same as described above,
but the cover bars on the longitudinal sides are missing and
the cover portion has different cut-away portions. Instead
of having the cover bars on the longitudinal sides, the
reinforcing rods 14 are supported by transversely disposed
rod holders 25 which also prevent liquid cement from penetra-
ting therein. The rod holders, which;are also formed from
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plastics material, have a length which corresponds to the
width of the box 1 and a cross-section, which is shown in
Figure 9, i.e. having a box-shaped form with a wide, circum-
ferential edge 26, whereby the two side edges come to lie on
the longitudinal sides of the box 1, and the cover portion is
supported on all four circumferential edges. The upper
portion of the rod holder converges in the centre to form
a rib 27 which has a longitudinal central slot 28 extending
to the openings 29 which are disposed at each end and
through whic~ the two shanks of the reinforcing rod 14 engage.
The rib may have a reinforced portion 30 in the centre. On
one side, the support member is connected to a hold-down
member 31 which, as the name suggests, serves to hold-down the
reinforcing rods.
For the assembly of the reinforcing rod holder, the
rods are first of all isnerted into the box 1 with the bent
shank ends which converge towards the centre, certain markings
possibly having been applied previously to determine the
spacings between the rods. The rod holders are then passed
over the clamps and pressed-down, whereupon the cover plate ~2
is mounted thereon. The cover plate 32, in addition to having
the above-described holes 8 for the pins 7, is provided with
transversely extending slots 33 which are disposed according
to the desired spacings between the reinforcing rods. As
stated above, the pins 7 are subsequently pressed-down, either
by means of a hammer, by compressed air or by a suitable device,
and consequently the cover plate is secured to the box. As the
cover plate is pressed-down, it also presses upon the circumfer-
ential edge 26 of the rod holder whereby, on the one hand, the
rod holder acts on the shank ends of the reinforcing rod
together with the hold-down member 31 and, on the other hand,
causes the slot 28 in the rod holder to be compressed, whereby
liquid cement is effectively prevented from penetrating therein.
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In a modified arrangement, the two longitudinal sides 3a of
the box l may have recesses in which the two transverse edges
of the rod holder engage in order to permit the insertion
of these edges at predetermined locations. As can be seen
from Fig. 9, in particular, the use of rod holders having a
central rib ensures that the entire curvature of the
reinforcing rods is situated inside the holder, thereby
ensuring complete straightening after they have been embedded
in concrete.
Figures 10 and 11 illustrate another embodiment of a
reinforcing rod holder which, compared with the preceding
example, provides further simplification both in the manufac-
ture and in the assembly. Here also, the box 34 has a
circumferential, double, U-shaped edge 35 with an inner wall
36 and an outer wall 37. The indentations 38 here are
substantially longer than those in the two preceding examples,
with the result that more concrete can pass behind the cover
plate for better securement thereof. At the top end of each
of the two longitudinal sides 39 of the inner edge 36, there
is a shoulder portion 40 on which the edges 41 of the
transverse sides of the rod holders 42 are supported, such
edges being correspondingly shorter than those described
in the preceding embodiment. The box also has a longitudinally
central rib 43, which is raised from the base to substantially
the same height as the circumferential edge 35. The hold-down
member 44 of the rod holder is provided with recesse 45 which
are disposed on both sides of the longitudinally central rib
43 and serve as guide means. To permit the reinforcing rods
to be accurately aligned before the cover plate 46 is
deposited, it is preferable to provide means for aligning
the rod holders. Such means may be, for examole, small
recesses 47 which are provided on the sides of the longtitud-
inally central rib and in which corresponding cams 48 engage,
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such cams being disposed at the guiding ends 49 - facing
the longitudinally central rib 43 - of the recesses 45 in
the hold-down member. However, other marking means may
also be provided; for example, small pins may be provided
on the upper edge of the longitudinally central rib, such
pins engaging in holes in the hold-down member, or vice
versa. In order to ensure an approximate alignment of the
reinforcing rods during their insertion into the box,
corresponding markings may be provided on the longitudinal
edges of the box. The cover plate 46 is of a design similar
to that of the preceding example, but here the pins 7 are
only disposed on the circumferential edge and engage in
corresponding openings 8. However, it is also possible to
provide pins on the longitudinally central rib 43, such
pins engaging through corresponding openings in the cover
- portion. The rib 50 in the rod holder does not have any
reinforcement in the centre and is particularly well-suited
to forming a tight seal, since it has been shown that, when
a pressure is exerted upon the edges 41 which are disposed
on both sides f the rib, the two edges of the slot 51 in
the rib are pressed towards each other.
For the purpose of securing the rods in the holder,
it is advantageous to use holder inserts 52 which are also
supported on the two shoulder portions 40 of the longitudinal
edges and have recesses 53 disposed on both sides of the
longitudinally central rib 43.
The component parts can be stacked one inside the other
or one above the other in a very space-saving manner and be
transported.
The assembly for this last-described rod holder is
very simple. First of all, the reinforcing rods are inserted
at previously designated locations; the rod holders are
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mounted at the marked locations and the holder inserts are
placed thereon; subsequently the cover plate is mounted and
then the pins are compressed by means of a hammer or a
suitable device in order to secure the cover plate. It is
apparent from the description, especially from the last two
examples, that it is not necessary for any tools to be used
for the assembly of this reinforcing rod holder e~cept a
hammer or, for a rational assembly, a pneumatically driven
press, and the assembly is conceptually simple.
However, the reinforcing rod holder offers substantial
advantages not only in terms of its manufacture and assembly,
but also in terms of its securement and in terms of erecting
the connecting wall. By providing the rod holders with the
raised rib 50, or 27 in the preceding example, the second wall
is provided with a tooth-like arrangement relative to the
first wall and increases the securement.
Figure 12 is a sectional view of a portion of a
secured relnforciny rod holder. The two casing boards 21
and 22 are visible, and it can be seen that the reinforcing
rod holder is secured in the casing board 22 by means of
nails 27. Nailing the reinforcing rod holder is considerably
simplified in that the nails can be hit through the opening 8
and, above all, through the pins 7, with the result that the
suitable locations can very easily be discovered, whereby
the nails are partially guided. After the rod holder has
been embedded in concrete, the free ends 24 of the reinforcing
rod are straightened (see Fig. 13), and subsequently the box
is easlly removed. If necessary, the cover bars 11 are
also removed. As already mentioned above, because concrete
engages behind the cover plate 32, 2 or 46, it is ensured
that said plate is firmly anchored in the wall and is not
loosened either when the reinforcing rod is straightened or
when the box portion is pulled away.
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In the two last-described embodiments also, the box
is preferably formed from a plastics film, but it is also
possible here to use instead a different material, cardboard
for example. The material of the cover plates 32 or 4O is
the same as that of the cover plate 2 in the first example
and may comprise expanded metal or a metal plate with a
roughened surface. In addition, the base of the box 1 or 34
has bearing and guide surfaces to ensure that the reinforcing
rods are securely held-down.
The three reinforcing rod holders, which are described
above and illustrated, relate to reinforcing rods provided
with a clamp and two free shanks, but it is possible to
provide a suitably modified reinforcing rod holder for
reinforcing rods which have only one shank and an open clamp.
: Thus, the width of the reinforcing rod will be only approx-imately half that of the reinforcing rod, as shown in Fig. 10
for example, and the other longitudinalwall which has the
same shoulder portion 40 is disposed at the location of the
longitudinally central rib 43. The-rod holders and the
holder inserts are then suitably shaped, i.e. the rod holders
have an opening in the centre and a suitably shaped hold-down
member, whereas the holder inserts have only one recess.
Here also, the reinforcing rods can first of all be inserted,
and then the rod holdersand the insert parts are deposited or
p~aced, whereupon the cover plate can be mounted and is
secured by means of the pins which extend through corres-
ponding openings.
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