Note: Descriptions are shown in the official language in which they were submitted.
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.
~C1.~Kh~ DOWEL PLACEMENT APPARATUS
Field of the Invention
The present invention relates generally to the art
of concrete construction, and more particularly to
devices for facilitating the placement of slip dowel rods
w th.n adJacQr.t c~rcrete ~labs.
Background of the Invention
In the art of concrete construction, it is
commonplace to form "cold joints" between two or more
poured concrete slabs. Such cold joints frequently
become uneven or buckled due to normal thermal expansion
and contraction of the concrete and/or compaction of the
underlying soil caused by inadequate substrate
preparation prior to pouring of the concrete. As a means
of preventing buckling or angular displacement of such
cold joints, it is common practice to insert smooth steel
dowel rods generally known as "slip dowels" within the
edge portions of adjoining concrete slabs in such a
manner that the concrete slabs may slide freely along one
or more of the slip dowels, thereby permitting linear
expansion and contraction of the slabs while at the same
time maint~; n; ng the slabs in a common plane and thus
preventing undesirable bucking or unevenness of the cold
joint.
In order to function effectively, slip dowels must
be accurately positioned parallel within the adjoining
concrete slabs. The non-parallel positioning of the
dowels will prevent the desired slippage of the dowels
and will defeat the purpose of the "slip dowel"
application. Additionally, the individual dowels must be
placed within one or both of the slabs in such a manner
as to permit continual slippage or movement of the dowels
within the cured concrete slab(s~.
In the prior art, two methods of installing smooth
~slip dowels" have become popular. According to the
first method, a first concrete pour is made within a pre-
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existing form. A~ter the first pour has cured, an edge
o:E the form (usually a wooden stud) is stripped away. A
series of holes are then drilled parallel into the first
pour along the exposed edge from which the form has been
5 removed. The depth and diameter of~ the individual holes
varies depending on the application and the relative size
of the concrete slabs to be supported. As a general
rule, however, such holes are at least 12 inches deep and
typically have a diameter of approximately five--eighths
lO of an inch.
After the parallel aligned series o~ holes has been
drilled into the Eirst pour, smooth dowel rods are
advanced into each such hole such that one end of each
dowel rod is positioned within the first pour and the
15 remainder of each dowel rod extends into a neighboring
area where a second slab of concrete is to be poured.
Thereafter, concrete is poured into such neighboring area
and is permitted to set with the parallel aligned dowels
extending thereinto. After the second pour has set, the
20 slip dowels will be held firmly within the second slab
but will be permitted to slide longitudinally within the
drilled holes of the first slab thereby accommodating
longitudinal expansion and contraction of the two slabs
while at the same time preventing buckling or angular
25 movement therebetween.
Although the above described "drilling method" of
placing slip dowels has become popular, it will be
appreciated that such method is extremely labor
intensive. In fact, it takes appro~imately ten minutes
30 to drill a five--eighths inch diameter by twelve inches
long hole into the first pour, and the drilling
equipment, bits, accessories, and associated set up time
tends to be very expensive. Moreover, the laborers who
drill the holes and place the slip dowels must be
35 adequately trained to insure that the dowels are arranged
perpendicular to the joint but parallel to one another so
as to permit the desired slippage during subsequent use.
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The second popular method of placing slip dowels
involves the use of wax treated cardboard sleeves
positioned over one end of each individual dowel.
According to such method, a series of holes are drilled
through one edge of a concrete form and smooth dowels are
~ advanced through each such hole. Wax treated cardboard
sleeves are placed over one end of each dowel and the
first pour is made within the form. After the first pour
has set, the previously drilled form is stripped away
leaving the individual dowels extending into a
neighboring open space where the second pour is to be
made. Subsequently, the second pour is made and
permitted to cure. Thereafter, the slip dowels will be
firmly held by the concrete of the second pour but will
be permitted to longitll~; n~ 1 ly slide against the inner
surfaces of the wax treated cardboard sleeves within the
first pour. Thus, the waxed cardboard sleeves
facilitate longitudinal slippage of the dowels, while at
the same time holding the two concrete slabs in a common
plane, and preventing undesirable buckling or angular
movement thereof.
This second method, while presently popu~ar, is
nonetheless associated with numerous deficiencies. For
example, after the first pour has been made, the free
ends of the dowels are likely to project as much as
eighteen inches through the forms and into the open space
allowed for the second pour. ~ecause the drilled section
of form must be advanced over those exposed sections of
dowel to accomplish stripping or removal of the form, it
is not infrequent for the exposed portions of the dowels
to become bent and, thus, nonparallel. Also, the drilled
section of form may become damaged or broken during the
removal process, thereby precluding its reuse.
It is unfortunate that both of the above-described
popular methods of placing slip dowels often result in
the dowels being finally positioned at various angles
rather than in the desired parallel array. When such
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occurs, the necessary slippage of the dowels is impeded
or prevented.
There i5 also known in the prior art dowel placement
devices which comprise elongate, hollow tubes sized to
receive portions of the dowel rods. The tubes are
mounted to one edge of the concrete form in generally
parallel relation to each other via integral base
portions, with a first pour being made thereabout. After
the first pour has cured, the edge of the concrete form
to which the tubes are mounted is stripped away from the
~irst slab, with dowel rods being advanced into the
exposed open ends of the tubes embedded within the ~irst
slab. Those portions of the dowel rods not advanced into
the tubes extend into a neighboring area where a second
pour of concrete is to be made. The pouring of the
concrete into the neighboring area encapsulates the dowel
rods which are held firmly within the second slab formed
by the curing of the second pour. The dowels, though
being firmly held within the second s~ab, are permitted
to slide longitudinally within the tubes embedded in the
first slab.
Though the use of these prior art placement devices
presents advantages over the previously described
placement methods, these devices also possess certain
deficiencies which detract from their overall utility.
In particular, the attachment of the base portions of
these prior art placement devices to a concrete form
often requires the use of multiple ~asteners, which makes
the attachment process a difficult and ti c consuming
task. Additionally, in the prior art placement devices
both the tube and its integral base portion used to
facilitate the connection of the tube to the concrete
form are embedded in the first slab, thus necessitating
that additional placement devices be attached to the
concrete form prior to its reuse. Further, the prior art
placement devices are generally only suited for
attachment to a concrete ~orm, and not to reinforcement
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materials such as rebar or wire mesh. As such, the prior
art placement devices do not lend themselves to use
within the interior areas of a poured slab, but rather
are limited to use along the peripheral edges of the slab
which are defined by the concrete form to which the
~ placement devices must be attached.
Accordingly, there r~ -; n~ a need in the art for
methods and/or devices for facilitating the proper
placement of slip dowels which overcome the previously
described deficiencies associated with prior art
placement devices.
Summary of the Invention
In accordance with one embodiment of the present
invention, there is provided a concrete dowel placement
apparatus which comprises a base member and an elongate,
tubular dowel receiving sheath which is connectible to
the base member. The base member itself comprises an
outer sleeve having first and second ends, and an inner
sleeve which is disposed within the outer sleeve.
Extending between the inner and outer sleeves is at least
one reinforcement wall, while extending about the first
end of the outer sleeve is a flange portion which defines
a generally flat back surface. The inner sleeve defines
an aperture which extends from the second end of the
outer sleeve to the back surface of the flange portion,
and is sized to accommodate a fastener to facilitate the
attachment of the base member to a concrete form
subsequent to the abutment of the back surface of the
~lange portion thereagainst. The sheath itself has an
open proximal end, a closed distal end and a hollow
interior compartment extending longitl~; n~l ly therein.
To facilitate the connection of the sheath to the base
member, the open proximal end of the sheath is slidably
extensible over the outer sleeve such that the outer
sleeve resides within the interior compartment of the
sheath.
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The inner and outer sleeves of the base member each
have generally circular cross-sectional configurations,
with the inner sleeve being concentrically positioned
within the outer sleeve. Additionally, the base member
preferably includes four reinforcing walls extending
between the inner and outer sleeves at intervals of
approximately 90 degrees, with the flange portion having
a generally circular configuration. The outer sleeve may
alternatively have a generally square cross-sectional
configuration, with the inner sleeve having a generally
circular cross-sectional configuration and being
centrally positioned within the square outer sleeve.
In accordance with another embodiment of the present
invention, there is provided a concrete dowel placement
apparatus having a base member which comprises a hollow
sleeve having first and second ends, and a flange portion
which extends about the first end of the sleeve and
defines a generally flat back surface. Disposed within
the flange portion is at least one aperture which is
sized to permit the passage of a fastener such as a nail
therethrough to facilitate the attachment of the base
member to a concrete form subsequent to the abutment of
the back surface of the flange portion thereagainst. The
placement apparatus of this embodiment further includes
the previously described sheath, the open proximal end of
which is slidably extensible over the sleeve of the base
member such that the sleeve resides within the interior
compartment of the sheath. The sleeve and flange portion
of the base member each have square configurations, with
the flange portion including a pair of fastener receiving
apertures disposed therein on opposite sides of the
square sleeve.
In accordance with another embodiment of the present
invention, there is provided a concrete dowel placement
apparatus which comprises an elongate, tubular dowel
receiving sheath having an open end, a closed end, an
outer surface, and an inner surface which defines a
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hollow, longitudinally extending interior compartment.
Formed on the outer surface of the sheath is a pair of
clips which extend outwardly in spaced, generally
parallel relation to each other. The clips are sized and
configured to facilitate the attachment of the sheath to
a piece of concrete reinforcement material.
This particular embodiment of the placement
apparatus may be used in combination with a foam plug
which is removably inserti~le into the open end of the
sheath. The clips of the sheath each preferably define
a first arcuate recess which is sized to receive a piece
of rebar, and a second arcuate recess which is sized to
receive a segment of wire mesh. The sheath itself has a
generally circular cross-sectional configuration, with
the clips extending radially outward from the outer
surface adjacent respective ones of the open and closed
ends. The outer surface of the sheath preferably
includes spiral ribs formed thereon.
In accordance with another embodiment of the present
invention, there is provided a concrete dowel placement
apparatus wherein the base member comprises a tubular
sleeve having first and second ends and inner and outer
surfaces. Extending about the first end of the sleeve is
a flange portion which defines generally flat front and
back surfaces. The sleeve extends perpendicularly from
the front surface of the flange portion. The base member
is attachable to a concrete form through the extension of
the sleeve through a bore in the form in a manner wherein
the front surface of the flange portion is abutted
thereagainst.
This particular placement apparatus further includes
the previously described elongate, tubular dowel
receiving sheath (not including the clips), the open
proximal end of which is slidably insertible into the
second end of the sleeve to facilitate the connection of
the sheath to the base member. In this respect, the
inner surface of the sleeve preferably includes
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longitudinally extending ribs formed thereon to
facilitate the frictional retention of the sheath within
the base member.
The base member of this placement apparatus may
further comprise an annular locking ring which is
extensible over the outer surface of the sleeve in a
manner wherein the concrete form is captured between the
flange portion and the locking ring when the base member
is attached thereto. Alternatively, the outer surface of
the sleeve may include barbs formed thereon to facilitate
the retention of the sleeve within the bore when the base
member is attached to the concrete form. Rather than
including the barbs, the outer surface of the sleeve may
be threaded, with the back surface of the flange portion
including a pair of tabs formed thereon, the threads
facilitating the retention of the sleeve within the bore
when the base member is attached to the concrete form.
Brief Descrip~ion of the Drawings
These, as well as other ~eatures of the present
invention, will become more apparent upon reference to
the drawings wherein:
Figure 1 is a front perspective view of a concrete
dowel placement apparatus constructed in accordance with
one embodiment of the present invention;
Figure 2 is an exploded view il~ustrating the manner
in which the base member of the placement apparatus shown
in Figure 1 is attached to a section of a concrete form;
Figure 3 is a partial perspective view of three
separate placement apparatuses as shown in Figure 1
attached to a section of a concrete form;
Figure 4 is a partial perspective view of a poured
concrete slab abutted by the section of the concrete form
shown in Figure 3 and having a plurality of placement
apparatuses as shown in Figure 1 embedded therein;
Figure 5 is a partial perspective view of the poured
concrete slab shown in Figure 4 having a plurality of the
sheaths of the placement apparatuses shown in Figure 1
-
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WO97/18354 PCT~S96/18057
.
embedded therein following the stripping away of the
section of the attendant concrete form;
Figure 6 is a longitudinal cross-sectional view of
a cold joint formed between two poured concrete slabs
with a slip dowel extending therebetween and positioned
within the sheath of a placement apparatus as shown in
Figure 1;
Figure 7 is a perspective view of a concrete dowel
placement apparatus constructed in accordance with
another embodiment of the present invention;
Figure 8 is a cross-sectional view taken along line
8-8 of Figure 7;
Figure 9 is a top plan view of a concrete slab in
which the placement apparatus shown in Figure 7 is
preferably used;
Figure 10 is a partial perspective view illustrating
the manner in which the placement apparatus shown in
Figure 7 is attached to a piece of concrete reinforcement
material prior the pouring of the concrete slab;
Figure 11 is a cross-sectional view taken along line
11-11 of Figure 10;
Figure 12 is a perspective view of a dowel placement
apparatus constructed in accordance with another
embodiment of the present invention, illustrating the
manner in which the placement apparatus is attached to a
concrete form;
Figure 13 is an exploded view of the components
comprising the base member of the placement apparatus
shown in Figure 12;
Figure 14 is a side elevational view of the
placement apparatus shown in Figures 12 and 13,
illustrating the manner in which the sheath is inserted
into the base member;
Figure 15 is a longitUdinal cross-sectional view of
a cold joint formed between two poured concrete slabs
with a slip dowel extending therebetween and positioned
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--10--
within the concrete dowel placement apparatus shown in
Figures 12 and 13;
Figure 16 is an e~ploded view of a concrete dowel
placement apparatus constructed in accordance with
another embodiment of the present invention;
Figure 17 is a perspective view of the base mem~er
of a concrete dowel placement apparatus constructed in
accordance with another embodiment of the present
invention;
Figure 18 is an exploded view illustrating a foam
plug which may be used with the concrete dowel placement
apparatus shown in Figure 7;
Figure 19 is a partial perspective view illustrating
the manner in which the placement apparatus shown in
Figure 18 is attached to a piece of concrete
reinforcement material and interfaced to a section of a
concrete form;
Figure 20 is a cross-sectional view ta~en along line
20-20 o~ Figure 19;
Figure 21 is a longitudinal cross-sectional view of
a cold joint formed between two poured concrete slabs
with a slip dowel extending therebetween and positioned
within a placement apparatus as shown in Figures 7 and
18-20;
Figure 22 is a cross-sectional view of a concrete
dowel placement apparatus constructed in accordance with
another em~odiment of the present invention; and
Figure 23 is a perspective view of a concrete dowel
placement apparatus constructed in accordance with
another embodiment of the present invention.
Detailed Description of the Preferred ' ' 'i -~ts
Referring now to the drawings wherein the showings
are ~or purposes for illustrating preferred embodiments
of the present invention only, and not for purposes ~or
limiting the same, Figures 1 and 2 illustrate a concrete
dowel placement apparatus 10 constructed in accordance
with a ~irst embodiment of the present invention. The
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placement apparatus 10 comprises a base member 12 and an
elongate, tubular dowel receiving sheath 14 which is
connectible to the base member 12 in a manner which will
be described in more detail below.
In the first embodiment, the base member 12 itself
comprises an outer sleeve 16 which has a generally
circular cross-sectional configuration. Formed on one
end of the outer sleeve 16 and extending radially outward
therefrom is a circularly configured flange portion 18.
The flange portion 18 includes a chamfered peripheral
edge 20, and defines generally planar or flat front and
back surfaces, with the outer sleeve 16 extending
perpendicularly (i.e., axially) from the front surface
thereof.
Concentrically positioned within the outer sleeve 16
is a tubular inner sleeve 22 which also has a generally
circular cross-sectional configuration. In the first
embodiment, the inner sleeve 22 defines an aperture 24
which extends from the end of the outer sleeve 16
opposite that including the flange portion 18 formed
thereon to the back surface of the flange portion 18.
~he aperture 24 is used to permit the passage of a
fastener 26 such as a nail through the base member 12 to
facilitate the attachment thereof to a wooden concrete
form 28, as will also be discussed in more detail below.
Extending between the outer and inner sleeves 16, 22 are
four (4) reinforcing walls 30 which are separated from
each other by intervals of approximately 90 degrees. The
reinforcement walls 30 significantly increase the
structural integrity of the base member 12, thereby
preventing any deformation thereof when attached to the
concrete form 28. The base member 12 is preferably
fabricated from a plastic material, though other
materials may be utilized as an alternative to plastic.
The sheath 14 of the placement apparatus 10 includes
an open proximal end 32, a closed distal end 34, and an
inner surface which defines a hollow, longitudinally
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-12- .
extending interior compartment 36 therewithin. Formed on
the outer surface of the sheath 14 are a plurality of
spiral ribs 38. In the first embodiment, the open
proximal end 32 of the sheath 14 is slidably extensible
over the outer sleeve 16 in a manner wherein the outer
sleeve 16 resides within the interior compartment 36. In
this respect, the inner surface of the sheath 14 defining
the interior compartment 36 has a diameter which slightly
exceeds the outer diameter of the outer sleeve 16. As
will be recognized, the outer sleeve 16 is fully extended
into the interior compartment 36 when the proximal end 32
of the sheath 14 is abutted against the front surface of
the flange portion 18. The sheath 14, like the base
member 12, is also preferably fabricated from a plastic
material.
The attachment of the placement apparatus 10 to the
concrete form 28 is accomplished by initially abutting
the flat back surface of the flange portion 18 against
one side of the concrete form 28~ As will be recognized,
the overall diameter of the flange portion 18 is
preferably sized so that the peripheral edge 20 thereof
does not extend beyond the edges of the side of the form
28 to which the ~ase member 12 is secured. Once the base
member 12, and in particular the flange portion 18
thereof, has been properly positioned on one side of the
concrete form 28, the fastener 26 is extended through the
aperture 24, and driven into the form 28. The fastener
26 or nail is fully driven into the concrete form 28 when
the enlarged head portion thereof comes into contact with
the end of the inner sleeve 22. Subsequent to the
attachment of the base member 12 to the concrete form 28,
the open proximal end 32 of the sheath 14 is slidably
extended over the outer sleeve 16 in the aforementioned
manner. As previously indicated, neither the outer or
inner sleeves 16, 22 of the base member 12 are
permanently deformed when the fastener 26 is driven into
the concrete form 28 by a tool such as a hammer due to
_
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--13--
the increased structural integrity provided to the base
member 12 by the inclusion of the reinforcement walls 30.
The manner in which multiple placement apparatuses
10 are typically employed is illustrated in Figures 3 - 6.
As shown, a series of placement apparatuses 10 are fixed
to a common side of the concrete form 28 in equidistantly
spaced relation to each other, such that the sheaths 14
extend perpendicularly from the common side of the
concrete form 28 in substantially parallel relation to
each other. The attachment of each placement apparatus
10 to the form 28 is accomplished in the previously
described manner, i.e., by driving the fastener 26
through the base member 12 and into the form 28.
Thereafter, the form 28 is held firmly in position by
stakes 40, as seen in Figure 4. A first concrete pour is
then made within the form 28 which encapsulates the
sheaths 14 as well as the front surfaces of the flange
portions 18 which remain exposed. Upon curing, the first
pour forms a first concrete slab 42.
After the first slab 42 is set, the form 28 is
stripped away therefrom. Importantly, when the form 28
is stripped away, the base members 12 of the placement
apparatuses 10 remain in attachment thereto, with the
flange portions 18 being removed from within the first
2~ slab 42 and the outer sleeves 16 being pulled from within
the interior compartments 36 of the sheaths 14. The
removal of the flange portions 18 from within the first
slab 42 is aided by the chamfered configuration of the
peripheral edges 20 thereof. Additionally, the circular
configuration of the flange portions 18 prevents cracking
in the edge of the first slab 42 which often occurs at
the corner regions of square or rectangular flanges.
Thus, only the sheaths 14 remain embedded within the
first slab 42, with the open proximal ends 32 thereof
35 being centrally positioned within circularly configured
recesses defined in the edge of the first slab 14 by the
removal of the flange portions 18 from therewithin. The
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-14-
adhesion of the poured concrete to the sheaths 14 is
enhanced by the inclusion o~ the spiral ribs 38 thereon.
As seen in Figure 5, after the form 28 has been
stripped away from the first slab 42 (thus separating the
base members 12 from the sheaths 14), sections of dowel
rod 46 are advanced into respective ones o~ the sheaths
14 embedded in the ~irst slab 42 via the exposed open
proximal ends 32 thereof. The dowel rods 46 may be
smooth, or may alternatively be formed of segments of
conventional rebar. The portions of the dowel rods 46
advanced into the sheaths 14 remained slidably disposed
therein, with the r~m~; ni ng portions o~ the dowel rods 46
extending outwardly into an adjacent space 48 wherein a
second concrete pour is to be made.
As seen in Figure 6, a second pour of concrete is
then made into the space 48 which completely encapsulates
the exposed portions of the dowel rods 46. The second
pour of concrete is then allowed to set thereby ~orming
a second concrete slab 50. A cold joint or seam 52
extends between the first and second slabs 42, 50.
Importantly, through the use of the placement apparatuses
10, the dowel rods 46 remain parallel to one another and
longitudinally slidable within the sheaths 14 embedded in
the ~irst slab 42, while being firmly cured in place
within the second slab 50. By such arrangement, the
first and second slabs 42, 50 are permitted to undergo
longitudinal ~p~n~ion and contraction along the dowel
rods 46 while at the same time being prevented from
buckling or undergoing vertical or angular displacement
at the cold ~oint or seam 52. As further seen in Figure
6, the circularly configured recesses in the ~irst slab
42 which are created by the removal of the flange
portions 18 from therewithin are filled by the second
pour, thus eliminating the ~ormation of any voids between
the abutting edges o~ the fir~t and second concrete slabs
42, 50.
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As previously explained, the base members 12 of the
placement apparatuses 10 remain in attachment to the
concrete form 28 when the same is stripped away from the
first slab 42. As such, the form 28 may be ~uickly re-
used after additional sheaths 14 are slidably extendedover the outer sleeves 16 of the base members 12.
Indeed, the process of attaching the base members 12 to
the concrete form 28 need only be conducted a single
time, with the form 28 and accompanying base members 12
being reusable after each slab is poured simply by
connecting new sheaths 14 thereto. The attachment of
each base member 12 to the form 28 via a single fastener
26 and reusability of the base members 12 provides a
significant advancement over prior art placement devices
which comprise a sheath portion and integral base
portion. The base portion is used to attach the prior
art placement device to the concrete form, with multiple
fasteners being needed to facilitate such attachment.
Once the concrete form is stripped away from the slab,
the prior art placement devices (comprising the
integrally connected sheath and base portions) are, in
their entirety, embedded within the concrete form. Thus,
prior to the re-use of the concrete form, the base
portions of new placement devices must be secured
thereto, which is a time consuming and therefore an
expensive process.
Referring now to Figure 16, there is depicted a
concrete dowel placement apparatus 54 constructed in
accordance with a second embodiment of the present
in~entiQP. ~.ich constitutes a slightly modified version
of the previously described placement apparatus 10
constructed in accordance with the first embodiment. The
placement apparatus 54 comprises a base member 56 which,
like the previously described base member 12, comprises
an outer sleeve 58 having a circularly configured flange
portion 60 extending radially outward from one end
thereof. The flange portion 60 also includes a chamfered
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-16-
peripheral edge 62, and defines generally planar front
and back surfaces, with the outer sleeve extending
perpendicularly from the front surface thereof. However,
rather than having a circular cross-sectional
configuration like the previously described outer sleeve
16, the outer sleeve 58 of the base mem~er 56 has a
generally square cross-sectional configuration.
Centrally positioned within the outer sleeve 58 is
a tubular inner sleeve 64 which has a generally circular
cross-sectional configura~ion and defines an aperture 66
extending from the end of the outer sleeve 58 opposite
that including the flange portion 60 formed thereon to
the ~ack surface of the flange portion 60. The aperture
66 is used for the same purpose as the aperture 24 of the
base mem~er 12. Extending between the outer and inner
sleeves 58, 64 are four (4) reinforcing walls 68 which
are separated from each other by intervals of
approximately 90 degrees, and are used to increase the
structural integrity of the base member 56. The base
member 56 is also preferably fabricated from a plastic
material.
In addition to the base member 56, the placement
apparatus 54 also includes the previously described
sheath 14, the open proximal end 32 of which is slidably
2~ extensible over the outer sleeve 58 in a manner wherein
the outer sleeve 58 resides within the interior
compartment 36 of the sheath 14. As will be recognized,
the inner surface of the sheath 14 defining the interior
compartment 36 has a diameter which slightly exceeds the
distance separating the diagonally opposed corners of the
outer sleeve 58 from each other. The outer sleeve 58 of
the base mem~er 56 is fully extended into the interior
compartment 36 when the proximal end 32 of the sheath 14
is abutted against the front surface of the flange
portion 60. The placement apparatus 54 constructed in
accordance with the second embodiment is used in the same
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-17-
manner as the placement apparatus 10 of the first
embodiment.
Referring now to Figure 17, there is depicted the
base member 72 of a placement apparatus constructed in
accordance with a third embodiment of the present
invention. The base member 72 comprises a hollow sleeve
which has a generally s~uare cross-sectional
configuration. Formed on one end of the sleeve 74 and
extending outwardly therefrom a generally square flange
portion 76 which defines flat front and back surfaces and
includes radiused corner regions. The sleeve 74 extends
perpendicularly from the front surface of the flange
portion 76.
Disposed within the flange portion 76 on opposite
sides of the sleeve 74 is a pair of apertures 78, each of
which is sized to permit the passage of a fastener such
as a nail therethrough to facilitate the attachment of
the base member 72 to a concrete form subsequent to the
abutment of the back surface of the flange portion 76
against the form~ Though not shown, the placement
apparatus of the third embodiment which includes the base
member 72 further includes the previously described
sheath 14, the open proximal end 32 of which is slidably
extensible over the sleeve 74 in a manner wherein the
sleeve 74 resides within the interior compartment 36 of
the sheath 14. In this respect, the inner surface of the
sheath 14 defining the interior compartment 36 has a
diameter which slightly exceeds the distance separating
the diagonally opposed corners of the s~uare sleeve 74
from each other. The sleeve 74 is fully extended into
the interior compartment 36 when the proximal end 32 of
the sheath 14 is abutted against the front surface of the
flange portion 76. The base member 72 is also preferably
fabricated from a plastic material.
Referring now to Figures 7 and 8, there is depicted
a concrete dowel placement apparatus 80 constructed in
accordance with a fourth embodiment of the present
CA 022376~1 1998-05-14
WO 97/18354 PCT/US96/18057
--18--
invention. The placement apparatus 80 comprises an
elongate, tubular dowel receiving sheath 82 which has a
generally circular cross-sectional configuration and
includes an open end 84, a closed end 86, and an inner
surface 88 which de~ines a hollow, longitll~; n~l ly
extending interior compartment 90 therewithin. Formed on
the outer surface 92 of the sheath 82 are spiral ribs 94.
In the fourth embodiment, the sheath 82 includes a
pair of integral clips 96 which are formed on and extend
radially outward from the outer surface 92 in spaced,
generally parallel relation to each other. The clips 96
are identically configured, and are positioned in close
proximity to respective ones of the open and closed ends
84, 86 of the sheath 82. As will be discussed in more
detail below, the clips 96 are each sized and configured
to facilitate the attachment o~ the sheath 82 to a piece
of concrete reinforcement material. As seen in Figure 8,
each of the clips 96 includes a pair of ~lexible prong
portions 98. Defined between the prong portions 98 is a
first arcuate recess 100 and a second arcuate recess 102
which is substantially smaller than the ~irst recess loO
and disposed closer to the outer sur~ace 92 of the sheath
82. In the placement apparatus 80, the first recess 100
is sized and configured to receive a piece of rebar, with
the second recess 102 being sized and configured to
receive a segment of wire mesh 104, as seen in Figures 10
and 11. The sheath 82 is also preferably fabricated from
a plastic material, though other materials may be
utilized as an alternative to plastic.
Referring now to Figures 9-11, placement apparatuses
80 constructed in accordance with the fourth embodiment
are typically used in conjunction with monolithic
concrete pours rather than in the cold joint doweling
application previously described in relation to the
placement apparatus 10 o~ the first embodiment. The use
of monolithic pours is a common practice in construction.
In monolithic pours, concrete is poured in large
CA 022376~l l998-0~-l4
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--19--
quantities without proper jointing primarily for purposes
of cutting costs. As seen in Figure 9, in typical
monolithic pours fracturing is prevented within the cured
concrete slab 106 by including tooled joints or sawcuts
108 in the slab 106 where cold joints would otherwise be
needed. Additionally, as seen in Figures 9-11, concrete
reinforcement material such as thé wire mesh 104 (or
alternatively segments of rebar) is initially placed into
the area in which the monolithic pour is to be made, and
~0 in particular those areas where it is contemplated that
sawcuts 108 will be included in the resultant slab 106
for purposes of preventing the fracturing thereof. The
wire mesh 104 or other reinforcement material is
preferably elevated above ground level by the placement
thereof upon support blocks or "chairsl' 110 in the manner
shown in Figures 10 and 11.
In addition to having concrete reinforcement
material disposed within those portions of the slab 106
in which a sawcut 108 is to be made, it is also desirable
to incorporate slip dowels into such portions to allow
the separate sections of the slab 106 which are defined
by the sawcuts 108 to move relative to each other while
preventing any buckling or angular displacement thereof.
One prior art method of incorporating slip dowels into
those areas of a monolithic pour where it is contemplated
that sawcuts will be made involves manually "stabbing"
the slip dowels into predetermined locations of the
uncured concrete pour. However, this method is deficient
in that there is no way to insure that the slip dowels
will be manually positioned within the uncured concrete
in parallel relation to each other, or will be maintained
in parallel alignment as the top surface of the concrete
pour is being finished. As previously explained, if the
dowel rods are not in parallel alignment, the separate
sections of the slab defined by the sawcuts will be
prevented from moving relative to each other. Another
prior art method o~ incorporating slip dowels into a
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-20-
monolithic pour involves manually tieing the slip dowels
to the reinforcement material in parallel relation to
each other prior to the concrete pour being made.
However, this manual tieing is extremely time consuming,
and presents significant difficulties in attempting to
secure the slip dowels to the reinforcement material in
true parallel relation to each other. Additionally, the
tied slip dowels are susceptible to displacement or
shifting when impacted by the concrete during the pour
thus moving the same out of parallel alignment with each
other.
The placement apparatus 80 constructed in accordance
with the fourth embodiment eliminates the deficiencies
associated with the prior art, and facilitates the quick
and easy placement of sheaths 82 and accompanying dowel
rods 46 into those areas of the slab 106 in which sawcuts
108 are to ~e included. Referring again to Figures 10
and 11, the concrete reinforcement material used within
the slab 106 is the wire mesh 104. Multiple sheaths 82
are secured to the wire mesh 104 in spaced, generally
parallel relation to each other via their clips 96 such
that the open ends 84 thereof extend in generally co-
planar relation to each other. The attachment of each
sheath 82 to the wire mesh 104 is facilitated by the
receipt of a straight segment of the wire mesh 104 into
the second recesses 102 of the clips 96 of the sheath 82.
Importantly, the receipt of the wire mesh segment into
the second recesses 102 facilitates a slight outward
flexion of the prong portions 98, thus causing the wire
mesh segment to be frictionally retained within the
second recesses 102. After the sheaths 82 have been
secured to the wire mesh 104, segments of dowel rod 46
are advanced into respective ones of the interior
compartments 90, with portions of the dowel rods 46
protruding axially from the open ends 84 of the sheaths
82, as seen in Figures 10 and 11. Importantly, the
placement apparatuses 80 are preferably oriented so that
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-21-
each sawcut 108 will extend in generally co-planar
relation to the open ends 84 of the sheaths 82. As
previously indicated, the dowel rods 46 advanced into the
interior compartments 90 of the sheaths 82 may be smooth
or may alternatively comprise segments of conventional
rebar.
As will be recognized, subsequent to the attachment
of the sheaths 82 to the wire mesh 104 and advancement of
the dowel rods 46 thereinto, the concrete is poured, with
the wire mesh 104, chairs 110 and placement apparatuses
80 (including the sheat~s 82 and dowel rods 46) being
completely encapsulated thereby. After the resultant
slab 106 is cured, the sawcuts 108 are made therein.
Though portions of the dowel rods 46 are held firmly
within the slab 106, those portions disposed within the
interior compartments 90 of the sheaths 82 are free to
slide longitudinally therewithin, thus allowing separate
sections of the slab 106 which are defined by the sawcuts
108 to move relative to each other. The adhesion of the
poured concrete to the sheaths 82 is aided by the spiral
ribs 94 formed on the outer surfaces 92 thereof. In the
event rebar is used as the concrete reinforcement
material as an alternative to the wire mesh 104, the
placement apparatuses 80 are used in the same manner
previously described, except that straight segments of
the rebar are inserted into and frictionally retained
within the larger size first recesses 100 of the clips 96
formed on the sheaths 82.
Referring now to Figures 18-21, as previously
e~plained, the placement apparatus 80 constructed in
accordance with the fourth embodiment is typically used
in monolithic concrete pours since it need not be
attached to a concrete form and may be placed inwardly of
the form which defines the periphery of the poured
concrete slab. However, the placement apparatus 80 may
also be used in cold joint applications with the
previously described wooden concrete form 28 as an
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-22-
alternative to the placement apparatuses of the first,
second and third em~odiments.
In particular, it is contemplated that the sheath 82
may be used in combination with a complimentary foam plug
112 which is removably insertible into the open end 84.
The foam plug 112 itself comprises a cylindrically shaped
body portion 114 having an elongate tail portion 116
extending a~ially from one end thereof. When fully
inserted into the open end 84 of the sheath 82, the body
portion 114 resides within the interior compartment 90,
with the tail portion 116 protruding ~rom the open end
84. After the foam plug 112 has been inserted thereinto,
the sheath 82 may be secured to the wire mesh 104 (or to
the rebar) in the previously described manner. However r
since the placement apparatus is being used to form a
cold joint rather than being used in a monolithic pour,
the sheath 82 must be oriented on the wire mesh 104 such
that the open end 84 thereof is ~lush with or extends
beyond the edge of the wire mesh 104 and is abutted
against one side of the concrete ~orm 28, as seen in
Figures 19 and 20. Due to the foam construction of the
plug 112, the abutment of the open end 84 of the sheath
82 against the concrete form 28 causes the tail portion
116 to be compressed between the form 28 and body portion
114 of the plug 112.
After the concrete has been poured within the form
28 and cures into a resultant slab 118, the form 28 is
stripped away from the slab 118. Importantly, the
stripping away of the ~orm 28 allows the compressed tail
portions 116 of the foam plugs 112 to resiliently return
to their uncompressed, e~tended configurations. The tail
portions 116 are then grasped and pulled outwardly, thus
removing the foam plugs 112, and in particular the body
portions 114 thereof, from within the interior
compartments 90 of the sheaths 82. The dowel rods 46 are
then advanced into respective ones of the sheaths 82
em~edded in the sla~ 118 via the exposed open ends 84
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-23-
thereof. The portions o~ the dowel rods 46 advanced into
the sheaths 82 remain slidably disposed therein, with the
r~mA; n; ng portions of the dowel rods 46 extending
outwardly into an adjacent space wherein a second
concrete pour is to be made.
As seen in Figure 21, a second pour of concrete is
then made which completely encapsulates the exposed
portions of the dowel rods 46. The second pour of
concrete is then allowed to set, thereby forming another
concrete slab 120. A cold joint or seam 122 extends
between the slabs 118, 120. Through the use of the
placement apparatuses 80, the dowel rods 46 remain
parallel to one another and longitudinally slidable
within the sheaths 82 embedded in the slab 118, while
being firmly cured in place within the slab 120. By such
arrangement, the slabs 118, 120 are permitted to undergo
longitll~; n~l expansion and contraction along the dowel
rods 46, while at the same time being prevented from
buckling or undergoing vertical or angular displacement
at the cold joint or seam 122.
Though not shown, it is known in the prior art to
provide the wire mesh 104 concrete reinforcement material
in rolls. In this respect, it is contemplated that the
sheaths 82 may be pre-attached to the wire mesh 104 in
desired locations prior to it being rolled for delivery.
As such, upon being unrolled within the confines of a
concrete form, the wire mesh 104 will already include the
sheaths 82 operatively placed thereupon.
Referring now to Figures 12-15, there is depicted a
concrete dowel placement apparatus 124 constructed in
accordance with a fifth embodiment of the present
invention. The placement apparatus 124 is adapted to be
used in conjunction with a concrete form 126 which is
intended to remain embedded between a first slab 128 and
an adjacent second slab 130 to form an intermediate cold
joint. In the fifth embodiment, the concrete ~orm 126 is
pre~erably fabricated from a fiber reinforced foamed
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-24-
plastic material, and includes a plurality of bores 132
pre-drilled thereinto in equidistantly spaced relation to
each other.
The placement apparatus 124 comprises a base member
134 and the previously described elongate, tubular sheath
14 which is connectible to the base member 134. The base
member 134 itself comprises a tubular sleeve 136 which
has a generally circular cross-sectional configuration.
Formed on one end of the sleeve 136 and extending
radially outward therefrom is a circularly configured
flange portion 138 which defines generally planar or flat
front and back surfaces. In this respect, the sleeve 136
extends perpendicularly (i.e., axially) from the front
surface of the flange portion 138. As best seen in
Figure 14, the flange portion 138 defines a centrally
positioned circular opening 140 which communicates with
the interior of the s~eeve 136, and an annular shoulder
142 which extends radially inward relative to the inner
surface of the sleeve 136. Formed on the inner surface
of the sleeve 136 in equidistantly spaced relation to
each other are a plurality of longitll~; n~ 1 ly extending
ribs 144 which terminate slightly inwardly from the end
of the sleeve 136 opposite that including the flange
portion 138 formed thereon.
As best seen in Figures 12 and 13, the base member
134 is attached to the form 126 via the slidable
extension of the sleeve 136 through a respective bore
132. Each bore 132 is sized having a diameter which
slightly exceeds the diameter of the outer surface of the
sleeve 136, thus allowing the same to be slida~ly
inserted thereinto. The base member 134 is fully
inserted into the form 126 when the ~ront surface of the
flange portion 138 is abutted against one side of the
form 126, as seen in Figure 15. The sleeve 136 is sized
having a length such that the end thereof not including
the flange portion 138 protrudes from the side of the
CA 022376~l l998-0~-l4
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-25-
form 126 opposite that including the front surface of the
flange portion 138 abutted thereagainst.
To maintain the base member 134 in firm engagement
to the form 128 subsequent to the extension of the sleeve
136 through the bore 132 in the aforementioned manner,
the placement apparatus 124 is further provided with an
annular locking ring 146. The loc~ing ring 146 is sized
and configured to be extensible over the outer surface of
the sleeve 136 and abutted against the concrete form 126
such that the form 126 is captured between the front
surface of the flange portion 138 and locking ring 146.
Subsequent to the attachment of the base member 134 to
the form 128 through the use of the locking ring 146, the
open proximal end 32 of the sheath 14 is slidably
extended into the sleeve 136. The extension of the
sheath 14 into the base member 34 is limited by the
abutment of the open pro~imal end 32 against the annular
shoulder 142. When such abutment occurs, the opening 140
and interior compartment 36 (which are of substantially
equal diameter) are aligned with each other.
Importantly, the sheath 14 is frictionally retained
. within the base member 134 by the ribs 144 formed on the
inner surface of the sleeve 136.
Referring now to Figure 15, after the base members
134 have been attached to the form 126 and the sheaths 14
connected to the base members 134, dowel rods 46 are
slidably advanced into the interior compartments 36 of
respective ones of the sheaths 14 via the openings 140 in
the flange portions 138. Thereafter, a first concrete
pour is made which encapsulates the sheaths 14 and
portions of the sleeves 136, and cures into the first
slab 128. A second concrete pour is then made which
encapsulates the flange portions 138 and exposed portions
- of the dowel rods 46, and cures into the second slab 130.
Once again, the portions of the dowel rods 46 advanced
into the sheaths 14 remain slidably disposed therein,
with the r~i n; ng portions of the dowel rods being
CA 022376~l lss8-0~-l4
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-26-
firmly cured in place within the ~econd slab 130. As
such, the first and second slabs 128, 130 are permitted
to undergo longitudinal expansion and contraction along
the dowel rods 46, while at the same time being prevented
from buckling or undergoing vertical or angular
displacement at the form 126. It will be recognized that
the form 126 may be provided with the base members 134
being pre-attached thereto.
Referring now to Figure 22, there i8 depicted a base
member 148 which may be used in the placement apparatus
124 as an alternative to the previously described base
member 134. The base member 148 includes a sleeve 150
which has a generally circular cross-sectional
configuration. Formed on one end of the sleeve 150 and
extending radially outward therefrom is a circularly
configured flange portion 152 which defines generally
flat ~ront and back sur~aces. The sleeve 150 extends
perpendicularly (i.e., axially) from the front surface of
the ~lange portion 152. The flange portion 152 further
defines a central opening 154 which communicates with the
interior of the sleeve 150 and an annular shoulder 156
- which extends radially inward relative to the inner
surface of the sleeve 150. Formed on the inner surface
of the sleeve 150 in equidistantly spaced relation to
each other are a plurality of longitudinally extending
ribs 158 which extend to the shoulder 156 and terminate
slightly inwardly from the end of the sleeve 150 opposite
that including the ~lange portion 152 formed thereon.
The base member 148 is also attached to the form 126
by the extension of the sleeve 150 through a respective
bore 132. When the base member 148 is fully inserted
into the form 126, the front surface of the flange
portion 152 is abutted against one side of the form 126,
with the end of the sleeve 150 opposite that including
the flange portion 152 formed thereon protruding from the
other side of the form 126. However, as an alternative
to the use of the previously described locking ring 146,
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WO97/18354 PCT~S96/18057
-27-
the base member 148 is maintained in rigid attachment to
the form 126 by the engagement of barbs 160 formed on the
outer surface of the sleeve 150 to the form 126. The
barbs 160 are directed toward the flange portion 152,
thus allowing the same to be forced through the bore 132.
Once forced through the bore 132, the barbs 160
frictionally retain the sleeve 150, and hence the base
member 148, within the form 126. The sheath 14 is
connected to the base member 148 in the same manner
previously described in relation to the connection of the
sheath 14 to the base member 134, i.e., by the slidable
insertion of the open proximal end 32 into the sleeve
150, with such insertion being limited by the abutment of
the open proximal end 32 against the annular shoulder
156. Once inserted into the base member 148, the sheath
14 is frictionally maintained within the sleeve 150 by
the ribs 148 formed on the inner surface thereof.
Referring now to Figure 23, there is depicted a base
member 162 which may also be utilized in the placement
apparatus 124 as an alternative to the base member 134.
The base member 162 itself comprises a sleeve 164 which
has a generally circular cross-sectional configuration.
Formed on one end of the sleeve 164 and extending
radially outward therefrom is a circularly configured
flange portion 166 which defines generally flat front and
back surfaces. The sleeve 164 extends perpendicularly
(i.e., axially) from the front surface of the flange
portion 166. The flange portion 166 further defines a
central opening 168 which communicates with the interior
of the sleeve 164 and an annular shoulder which extends
radially inward relative to the inner surface of the
sleeve 164. Additionally, formed on the inner surface of
the sleeve 164 in equidistantly spaced relation to each
- other are a plurality of longitll~;nAlly extending ribs
which extend to the shoulder defined by the flange
portion 166 and terminate slightly inward of the end of
CA 022376~l l998-0~-l4
WO 97/18354 PCT~S96/18057
- 28 -
the sleeve 164 opposite that including the flange portion
166 formed thereon.
~ s an alternative to the previously described barbs
160 formed on the outer surface of the sleeve 150, the
sleeve 164 of the base member 162 includes threads 170
formed on the outer surface thereof. Additionally,
formed on the back surface of the flange portion 166 in
opposed relation to each other and on opposite sides of
the opening 168 is a pair o~ identically configured,
semi-circular tab portions 172. Like the barbs 160, the
threads 170 are adapted to serve as an alternative to the
locking ring 146 to facilitate the retention of the base
member 162 within the form 126. In this respect, the
sleeve 164 iS extended through the bore 132 by rotating
it through the use of the tab portions 172. The
continued rotation of the sleeve 164 causes the same to
be drawn through the bore 132 until such time as the
front surface of the ~1ange portion 166 comes into
abutting contact with one side of the form 126. When
such abutment occurs, the end of the sleeve 164 not
including the flange portion 166 formed thereon protrudes
from the side of the form 126 opposite that against which
the flange portion 166 is abutted. Thereafter, the
sheath 14 iS connected to the base member 162 in the same
manner as previously described in relation to the
connection of the sheath 14 to the base members 148, 134.
Additional modifications and improvements of the
present invention may also be apparent to those skilled
in the art. For example, the flange portion and/or
sleeve o~ each base member may be provided in any
geometric shape (e.g., circular, square, triangular,
etc.), as may each sheath. Thus, the particular
combination of parts described and illustrated herein is
intended to represent only certain embodiments of the
present invention, and is not intended to serve as
limitations o~ alternative devices within the spirit and
scope of the invention.
