Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02324134 2000-10-24
PRE-CAST CONCRETE SLAT
Field of Invention
This invention relates to pre-cast concrete slats and, more particularly, to a
method of
manufacturing an improved pre-cast concrete slat with a textured surface.
Background of the Invention
The pre-cast concrete slats are designed for supporting livestock. Typically,
such concrete
slats include openings or slots to permit egress of animal wastes, thereby
contributing to a cleaner
environment for the livestock.
Figure 1 illustrates a cross-sectional elevation view of a mould used in
forming a typical prior
art concrete slat. Figure 2 illustrates a perspective view of another mould
used for such purposes.
The mould includes internal rigid steel cores for forming the above-described
openings or slots in
the concrete slat.
In order to help prevent livestock from losing their footing on concrete
slats, the concrete slat
is typically manufactured with a textured non-skid surface. Figure 3
illustrates a typical prior art
method of manufacturing such a textured concrete slat. A mould is typically
provided including
internal steel cores, much like the moulds illustrated in Figures 1 and 2. The
concrete is then poured
into the cavities of the mould. A rolling wheel having ribs is then rolled
across the surface of the
poured concrete. In order to ensure that the wheel does not ride on the
surface of the internal cores,
the wheels are characterized by a width which is less than the width between
the individual cores.
If the wheels were to ride on the steel surface of the internal cores, the
wheels would not then contact
the surface of the poured concrete and would, thereby, not form the textured
surface as desired.
However, because the width of the wheels is less than the distance between the
internal cores, the
wheel is unable to roll across the entire surface of the poured concrete. As a
result, the prior art
concrete slat is typically formed with raised surfaces at the edges between
the slots or openings, with
a depression therebetween (see Figures 4 and 5). Unfortunately, moisture is
permitted to collect in
this depression, thereby making it more uncomfortable for the livestock.
CA 02324134 2000-10-24
Summary of the Invention
It is an obj ect of the present invention to manufacture an improved pre-cast
concrete slat with
a textured surface.
In its broad aspect, the present invention provides method of manufacturing a
concrete slat
comprising the steps of: (a) pouring concrete into a cavity of a first mould
plate to provide an upper
surface of poured concrete, (b) applying textured paper across the upper
surface, (c) clamping a
second mould plate having a planar lower surface onto the first mould plate to
seal the first mould
plate and thereby form a closed mould having a longitudinal axis, and (d)
rotating the mould about
180 ° on the longitudinal axis such that the poured concrete presses
downwardly upon the textured
paper while being supported by the planar surface of the second mould plate,
and thereby forming
a first intermediate product. The method can also include the step of heating
the first intermediate
product to effect curing of the first intermediate product and formation of a
second intermediate
product. A wire mesh can also be applied across the textured paper between
steps (b) and (c). The
first mould plate can include cores for forming slots in the slat. The first
mould plate can further
include a base, sidewalls extending from the base to define a perimeter, and
internal cores extending
from the base and disposed within the perimeter for forming slots in the slat.
The concrete can
comprise zero-slump concrete. The textured paper can be creped paper.
In another aspect, the present invention provides a concrete slat manufactured
according to
a method comprising the steps of: pouring concrete into a cavity of a first
mould plate to provide an
upper surface of poured concrete, applying textured paper across the upper
surface, clamping a
second mould plate having a planar lower surface onto the first mould plate to
seal the first mould
plate and thereby form a closed mould having a longitudinal axis, and rotating
the mould about 180 °
on the longitudinal axis such that the poured concrete presses downwardly upon
the textured paper
while being supported by the planar surface of the second mould plate, and
thereby forming a first
intermediate product.
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CA 02324134 2000-10-24
In a further aspect, the present invention provides a method of manufacturing
a concrete slat
comprising the steps o~ (a) pouring concrete into a cavity of a first mould
plate to provide an upper
surface of poured concrete, (b) applying a flexible sheet across the upper
surface, (c) applying a wire
mesh across the flexible sheet, (d) clamping a second mould plate having a
planar lower surface onto
the first mould plate to seal the first mould plate and thereby form a closed
mould having a
longitudinal axis, and (e) rotating the mould about 180° on the
longitudinal axis such that the
poured concrete presses downwardly upon the textured paper while being
supported by the planar
surface of the second mould plate, and thereby forming a first intermediate
product.
In yet a further aspect, the present invention provides a concrete slat
manufactured according
to the method comprising the steps of: pouring concrete into a cavity of a
first mould plate to
provide an upper surface of poured concrete, applying a flexible sheet across
the upper surface,
applying a wire mesh across the flexible sheet, clamping a second mould plate
having a planar lower
surface onto the first mould plate to seal the first mould plate and thereby
form a closed mould
having a longitudinal axis, and rotating the mould about 180 ° on the
longitudinal axis such that the
poured concrete presses downwardly upon the textured paper while being
supported by the planar
surface of the second mould plate, and thereby forming a first intermediate
product.
By using gravity to cause poured concrete to press downwardly against an
irregular or
textured surface, the present invention provides an improved method of
manufacturing a concrete
slat with a textured upper surface, and avoids the undesirable formation of
depressions in the upper
surface as persists in prior art methods.
Brief Description of the Drawings
Further objects and advantages will appear from the following detailed
description of the
invention, taken together with the following drawings in which:
Figure 1 is a cross-sectional elevation view of a typical prior art mould used
to manufacture
a typical concrete slat with a textured non-skid surface;
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CA 02324134 2000-10-24
Figure 2 is a perspective view of another typical prior art mould used to
manufacture a
typical prior art concrete slat with a textured non-skid surface;
Figure 3 is a cross-sectional elevation view of a prior art method of
manufacturing a typical
concrete slat;
Figure 4 is a perspective view of a typical prior art concrete slat with a
textured non-skid
surface.
Figure 5 is a cross-sectional elevation view of the prior art concrete slat of
Figure 4 taken
along the lines S-5;
Figure 6 is a top plan view, partly in section, of the prior art concrete slat
of Figure 4 taken
along the lines 6-6;
Figures 7 to 17 are schematic perspective views of a method of manufacturing a
pre-cast
concrete slat with a textured non-skid surface of an embodiment of the present
invention.
Detailed Description
Figure 4 illustrates an embodiment of a livestock slat 10 of the present
invention. Slat 10 is
substantially rectangular in shape, defined by side edges 12, 14 and end edges
16, 18 which together
define perimeter 32 of slat 10. Slat 10 includes a generally horizontal floor
20 with an upper
textured flooring surface 22 and a lower surface 23. In one embodiment,
flooring surface 22 is
ribbed. Depending from floor 20 are a plurality of support beams 24a through
24c. Support beams
24a through 24c extend between the edges 16, 18.
Intermediate the support beams 24a through 24c, the concrete floor 20 is
pierced with rows
26 of spaced apart slots 28 which extend through floor 20. Slots 28 are
provided to facilitate egress
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CA 02324134 2000-10-24
of animal excrement from floor 20, thereby creating a cleaner and safer
environment for livestock
who are supported on top of slat 10.
Slots 28 are defined by interior endless wall 30 disposed intermediate side
edges 12, 14 and
end edges 16, 18. In other words, endless wall 30 is disposed within perimeter
32 of slat 10 and
remote from side edges 12, 14 and end edges 16, 18. Endless wall 30 is
substantially vertical and
joins flooring surface 22 to lower surface 23.
Manufacture of slat 10 will now be described with reference to Figures 7 to
17. Slat 10 is
formed by a moulding operating using mould 100. Mould 100 includes a first
plate 102 and a second
plate 104 and includes longitudinal axis 101 (see Figure 12). First plate 102
includes a cavity 106
formed therein. Cavity 106 receives poured concrete which conforms to the
shape of cavity 106 to
form slat 10. In this respect, cavity 106 is shaped to correspond with desired
structural features of
slat 10. Typically, cavity 106 is defined by sidewalk 108 and internal cores
110 extending from base
112. Sidewalk 108 define perimeter 109, and internal cores 110 are disposed
within perimeter 109.
Internal cores 110 are provided to form slots 28 in slat 10.
Second plate 104 includes a substantially planar surface 114 which supports
concrete poured
into cavity 106 while slat 10 is being manufactured.
Initially, first plate 102 is spaced apart from second plate 104 (Figure 7).
Wire reinforcing
mesh 116 is inserted within cavity 106 (Figure 8). As a next step, concrete
120 is poured from
hopper 118 and into cavity 106 and fills the interstitial spaces between
internal cores 110. The
poured concrete presents an upper surface 122 (Figure 9). Preferably, concrete
120 comprises zero-
slump concrete.
Once cavity 106 is filled with concrete, creped or textured paper 124 is
applied across the
upper surface 122 of the poured concrete and presents an opposing surface 126
to upper surface 122
(Figure 10). Creped paper 124 contributes to the formation of a textured
flooring surface 22 in slat
CA 02324134 2000-10-24
as will be described in greater detail below (Figure 10). An example of
suitable textured paper
124 is Creped NS craft paper untrimmed Item No. FRDCRP3048 manufactured by
Gummed Papers
Limited of Brampton, Ontario, Canada.
In one embodiment, after the creped paper 124 has been applied across the
upper surface 122,
wire mesh 128 is applied across the creped paper 124 such that the wire mesh
128 intersects a plane
orthogonal to upper surface 122. Wire mesh 128 contributes to the formation of
a ribbed or irregular
flooring surface 20 with alternating raised and depressed surfaces. It is
understood that creped paper
124 need not be interposed between wire mesh 128 and upper surface 122, and
that use of non-
textured paper or other flexible sheet also falls within the scope of the
invention.
After the creped paper 124 and wire mesh 128 have been applied over and across
the poured
concrete, second plate 104 descends and seats upon first plate 102, thereby
presenting planar surface
114 (Figure 11). Second plate 104 is clamped to first plate 102 to prevent
egress of concrete from,
and thereby seal, mould 100 in the subsequent operations to be described
below.
After second plate 104 is clamped to first plate 102, mould 100 is rotated
180° on
longitudinal axis 101, whereby gravity causes poured concrete in cavity 106 to
press upon creped
paper 124 while being supported by surface 114 of second plate 104 (Figure
12). Impressions are
thereby created by the creped paper 124 and wire mesh 128 in the concrete.
Plate 102 and 104 are
uncoupled, and first plate 102 is removed from second plate 104, leaving a
first intermediate product
130 supported upon second plate 104 (Figure 13)
While the first intermediate product 130 is still supported on the second
plate 104, the first
intermediate product 130 is heated in furnace 132 to effect curing of first
intermediate product 130
and formation of second intermediate product 134 (Figure 14) with a
longitudinal axis 135 (see
Figure 1 S). During the heating operation, temperature inside furnace 132 is
maintained within the
range of 85 °F to 110 °F. The duration of the heating step is 8-
24 hours. After the heating operation,
the second intermediate product 134 is removed from the second plate 104 and
rotated 180° about
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longitudinal axis 135 (Figure 15). Next, the creped paper 124 and wire mesh
128 are removed
(Figure 16), leaving slat 10 (Figure 17).
Although the disclosure describes and illustrates preferred embodiments of the
invention, it
is to be understood that the invention is not limited to these particular
embodiments. Many
variations and modifications will now occur to those skilled in the art. For
definition of the
invention, reference is to be made to the appended claims.
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