Note: Descriptions are shown in the official language in which they were submitted.
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POLYURETHANE VIBRATORY SCREEN
FIELD OF THE INVENTION
The present invention relates to an improved molded polyurethane screen.
BACKGROUND
Molded polyurethane screens having reinforcement therein are known in the art.
However, in
the past the dividing strips between the openings were relatively large,
thereby causing the
open area of the screen to be an undesirably low percentage of its surface,
thereby in turn
causing the screen to be relatively inefficient.
The present invention is an improvement over U.S. Patent Nos. 4,819,809 and
4,857,176. The
present invention provides improved screens with relatively high percentage
open screening
areas and high efficiencies.
SUMMARY
According to an exemplary embodiment of the present invention, a vibratory
screen includes:
a flexible molded polyurethane body having substantially parallel side edge
portions at
opposite ends of the body, a lower edge portion substantially perpendicular to
the side edge
portions, an upper edge portion substantially perpendicular to the side edge
portions and
opposite the lower edge portion, an upper surface, a lower surface, first and
second members
forming screening openings and third and fourth members. The first members
extend between
the side edge portions. The second members extend between the lower edge
portion and the
upper edge portion. The third and fourth members may have a thickness greater
than the first
and second members. The third members are substantially parallel and extend
transversely
between the side edge portions and have multiple first members therebetween.
The fourth
members are substantially parallel and extend transversely between the lower
edge portion
and the upper edge portion and have multiple second members therebetween.
Reinforcement
members are molded integrally with the third and fourth members.
According to an embodiment, there is provided a vibratory screen comprising: a
flexible
molded polyurethane body having substantially parallel side edge portions at
opposite ends of
the body, a lower edge portion transversely disposed between the side edge
portions, an upper
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edge portion disposed between the side edge portions and substantially
parallel and opposite
to the lower end portion, an upper surface, a lower surface, a first
integrally molded grid
structure, a second integrally molded grid structure, a third integrally
molded grid structure
and screen openings, wherein the first grid structure includes first and
second members
forming the screen openings, the first members substantially parallel and
extending
transversely between the side edge portions and the second members
substantially parallel and
extending transversely between the lower edge portion and the upper edge
portion, wherein
the second grid structure includes third and fourth members, the third members
substantially
parallel and extending transversely between the side edge portions and having
multiple first
members therebetween, the fourth members substantially parallel and extending
transversely
between the lower edge portion and the upper edge portion and having multiple
second
members therebetween, first reinforcement members molded integrally with the
first and
second members, wherein the third grid structure includes fifth and sixth
members, the fifth
and sixth members, the fifth members substantially parallel and extending
transversely
between the side edge portions and having multiple third members therebetween,
the sixth
members substantially parallel and extending transversely between the lower
edge portion and
the upper edge portion and having multiple fourth members therebetween,
reinforcement rods
molded integrally with at least one of the fourth members and sixth members.
According to another embodiment, there is provided a vibratory screen,
comprising: a flexible
molded polyurethane body having substantially parallel side edge portions at
opposite ends of
the body, a lower edge portion substantially perpendicular to the side edge
portions, an upper
edge portion substantially perpendicular to the side edge portions and
opposite the lower edge
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portion, an upper surface, a lower surface, first and second members forming
screen openings,
the first members extending between the side edge portions and the second
members
extending between the lower edge portion and the upper edge portion, third and
fourth
members, the third members substantially parallel and extending transversely
between the
side edge portions and having multiple first members therebetween, the fourth
members
substantially parallel and extending transversely between the lower edge
portion and the upper
edge portion and having multiple second members therebetween, reinforcement
members
molded integrally with at least one of the first and second members, and
reinforcement rods
molded integrally with the fourth members.
According to another embodiment, there is provided a vibratory screen,
comprising: a flexible
molded polyurethane body having substantially parallel side edge portions at
opposite ends of
the body, a lower edge portion substantially perpendicular to the side edge
portions, an upper
edge portion substantially perpendicular to the side edge portions and
opposite the lower edge
portion, an upper surface, a lower surface, first and second members forming
screen openings,
the first members extending between the side edge portions and the second
members
extending between the lower edge portion and the upper edge portion,
reinforcement members
molded integrally with the first and second members; and reinforcement rods
extending
between the side edge portions.
According to another embodiment, there is provided a method of making a
vibratory screen,
comprising: creating a mold configured to fabricate the vibratory screen, the
vibratory screen
having a flexible molded polyurethane body; installing reinforcement members
in the mold,
the reinforcement members configured to be molded integrally with the body;
installing
reinforcement rods in the mold, the reinforcement rods configured to be molded
integrally
with the body filling the mold with polyurethane; and forming the vibratory
screen, the
vibratory screen having substantially parallel side edge portions at opposite
ends of the body,
a lower edge portion substantially perpendicular to the side edge portions, an
upper edge
portion substantially perpendicular to the side edge portions and opposite the
lower edge
portion, an upper surface, a lower surface, first and second members forming
screen openings,
the first members extending between the side edge portions and the second
members
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extending between the lower edge portion and the upper edge portion,
reinforcement members
molded integrally with the first and second members, third members
substantially parallel and
having multiple first members therebetween, fourth members substantially
parallel and having
multiple second members therebetween, and reinforcement rods molded integrally
with the
fourth members.
According to another embodiment, there is provided a vibratory screen,
comprising: a flexible
molded polyurethane body, screen openings in the body, first substantially
parallel flexible
members defining opposite sides of the screen openings, second substantially
parallel flexible
members defining opposite sides of the screen openings, the first members
substantially
perpendicular to the second members, third members substantially parallel and
having
multiple first members therebetween, fourth members substantially parallel and
having
multiple second members therebetween, reinforcement rods molded integrally
with the fourth
members, side edge portions substantially parallel at opposite sides of the
body between
which the third members and reinforcement members therein extend, first and
second end
portions substantially parallel at opposite ends of the body between which the
fourth members
and reinforcement members therein extend, the side portions substantially
perpendicular to the
end portions.
According to another embodiment, there is provided a vibratory screen,
comprising: a flexible
molded polyurethane body having substantially parallel side edge portions at
opposite ends of
the body, a lower edge portion substantially perpendicular to the side edge
portions, an upper
edge portion substantially perpendicular to the side edge portions and
opposite the lower edge
portion, first and second members forming screen openings, the first members
extending
between the sided edge portions and the second members extending between the
lower edge
portion and the upper edge portion, third and fourth members, the third
members substantially
parallel and extending transversely between the side edge portions and having
multiple first
members therebetween, the fourth members substantially parallel and extending
transversely
between the lower edge portion and the upper edge portion and having multiple
second
members therebetween, fifth and sixth members, the fifth members substantially
parallel and
extending transversely between the side edge portions and having multiple
third members
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therebetween, the sixth members substantially parallel and extending
transversely between the
lower edge portion and the upper edge portion and having multiple fourth
members
therebetween, wherein reinforcement members are molded integrally with at
least one of the
first, third and fifth members and at least one of the second, fourth and
sixth members,
wherein reinforcement rods extend between the side members.
According to another embodiment, there is provided a vibratory screen,
comprising: a flexible
molded polyurethane body having substantially parallel side edge portions at
opposite ends of
the body, a lower edge portion substantially perpendicular to the side edge
portions, an upper
edge portion substantially perpendicular to the side edge portions and
opposite the lower edge
portion, first and second members forming screen openings, the first members
extending
between the sided edge portions and the second members extending between the
lower edge
portion and the upper edge portion, third and fourth members, the third
members substantially
parallel and extending transversely between the side edge portions and having
multiple first
members therebetween, the fourth members substantially parallel and extending
transversely
between the lower edge portion and the upper edge portion and having multiple
second
members therebetween, wherein reinforcement members are molded integrally with
at least
one of the first and third members and at least one of the second and fourth
members, wherein
reinforcement rods extend between the side members.
Example embodiments of the present invention are described in more detail
below with
reference to the appended Figures.
BRIEF DESCRIPTION OF TIIE DRAWINGS
FIG. 1 is a fragmentary plan view of a vibratory screen according to an
exemplary
embodiment of the present invention;
FIG. 1A is a top isometric view of the screen shown in FIG. 1;
FIG. 1B is a bottom isometric view of the screen shown in FIG. 1;
FIG. 2 is a fragmentary cross sectional view taken substantially along line 2--
2 of FIG. 1;
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FIG. 3 is a fragmentary cross sectional view taken substantially along line 3--
3 of FIG. 1;
FIG. 3A is an enlarged fragmentary cross sectional view of a portion of the
screen shown in FIG. 3;
FIG. 4 is a plan view of a portion of the screen shown in FIG. 1;
FIG. 4A is an enlarged plan view of a portion of the screen shown in FIG. 4.
FIG. 5 is a fragmentary cross sectional view taken substantially along line 5--
5 of FIG. 1;
FIG. 5A is an enlarged fragmentary cross sectional view of a portion of the
screen shown in FIG. 5;
FIG. 6 is an enlarged fragmentary cross sectional view similar to the view
taken substantially
along line 5--5 of FIG. 5, but showing only a cross section configuration of a
modified shape
of first members having reinforcement members;
1 0 FIG. 7 is a view similar to FIG. 6 but showing first members without
reinforcement members;
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FIG. 8 is a fragmentary cross sectional view showing the manner in which the
improved screen of FIG. 1 is mounted in a vibratory screening machine;
FIG. 9 is an enlarged isometric view of a portion of a vibratory screen
according to an
exemplary embodiment of the present invention having reinforcement members
integral with first and second members forming screen openings;
FIG. 10A is a top isometric view of a vibratory screen according to an
exemplary
embodiment of the present invention;
FIG. 10B is a bottom isometric view of the screen shown in FIG. 10A;
FIG. 11A is a top isometric view of view of a vibratory screen according to an
exemplary embodiment of the present invention;
FIG. 11B is a bottom isometric view of the screen shown in FIG. 11A;
FIG. 12 is a top isometric view of a vibratory screen with a portion of the
screen
removed showing reinforcement rods according to an exemplary embodiment of the
present invention;
FIG. 12A is an enlarged top isometric view of a portion of the screen shown in
FIG.
12.
FIG. 13 is an isometric view of a portion of a vibratory screening machine
having a
vibratory screen installed thereon according to an exemplary embodiment of the
present invention; and
FIG. 14 is an isometric view of a portion of a vibratory screening machine
having a
vibratory screen installed thereon according to an exemplary embodiment of the
present invention.
DETAILED DESCRIPTION
Like reference characters denote like parts in the several Figures.
According to an exemplary embodiment of the present invention, a vibratory
screen
10 includes a body 12 of molded polyurethane having unperforated side edge
portions
14, 16. Side edge portions 14, 16 may each have an upward U-shape and may each
include a cast-in structural member, such as angle 15 shown in FIG. 2. Side
edge
portions 14, 16 may also be formed without cast-in structural members and/or
may
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include other structural members. Side edge portions 14, 16 may be formed in a
U-
shape or any other suitable shape for attachment to a vibratory screening
machine. In
an exemplary embodiment, side edge portions 14, 16 may include a formed
member,
e.g., a metal member that is bent to a desired shape, e.g., a U-shape. The
formed
member may be attached to the polyurethane body by heating, pressing,
mechanical,
chemical, molding and/or any other suitable method/arrangement. Referring back
to
the figures, as shown in FIGS. 11A to 11B, angle 15 may form an upward U-
shape.
Angle 15 may extend the entire length of side edge portions 14, 16. Side
edge
portions 14, 16 may be configured for mounting vibratory screen 10 in a
vibratory
screening machine, as is well known. Body 12 also includes a lower edge
portion 18
and an upper edge portion 20 which, in combination with side edge portions 14,
16,
define an outer border of the screen 10. In certain embodiments, angle 15 may
be
included in upper edge portion 20 and lower edge portion 18. See, e.g., FIGS.
10A to
10B. In such embodiments, angle 15 may extend the entire length of upper edge
portion 20 and lower edge portion 18. In example embodiments, upper edge
portion
and lower edge portion 18 may be configured for mounting on a vibratory screen
1010 designed for mounting screens front to back. See, e.g., FIG. 13. Body 12
further includes an upper surface 22 and a lower surface 24 and includes first
members 101 and second members 102 forming screen openings 26. Body 12 may
20 further
include third members 203, fourth members 204, fifth members 305 and sixth
members 306. Body 12 may include various configurations of third members 203,
fourth members 204, fifth members 305 and/or sixth members 306. The third
members 203, fourth members 204, fifth members 305 and/or sixth members 306
may
or may not include reinforcement members 50 and are generally configured to
provide
support to screen openings 26 formed by first and second members 101, 102.
Body
12 may include first members 101 and second members 102 without third members
203, fourth members 204, fifth members 305 and/or sixth members 306. The first
and/or second members 101, 102 may be configured to include reinforcement
members 50. In certain embodiments, reinforcement rods 1050 may be
incorporated
into members running parallel to the edge portions of the screen having the
vibratory
machine attachment arrangements (e.g., the edges having the U-shaped
structural
members discussed herein). See, e.g., FIGS. 12 and 12A. Reinforcement rods
1050
provide stability to screen 10 by preventing the side edge portions, e.g.,
side edge
portions 14, 16 shown in FIGS. 10A, 10B, 11A, 11B, 12 and 12A, from deforming
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and/or hourglassing. Reinforcement rods do not run perpendicular to the edge
portions of the screen having the vibratory machine attachment arrangements as
they
are substantially rigid, provided for structural support and would generally
restrict
significant movement or deflection of the screen assembly when a force is
applied to
the edge portions that interface the vibratory screening machine tensioning
members.
In an exemplary embodiment, reinforcement rods 1050 may be integrated
(including
by molding integrally) with fourth members 204 and/or sixth members 306.
Reinforcement rods 1050 may be made of plastic, metal, polymer or any other
suitable material with the necessary structural properties.
First and second members 101, 102 form a first integrally molded grid
structure 100
that defines screen openings 26. Third and fourth members 203, 204 may form a
second integrally molded grid structure 200. Reinforcement rods 1050 may be
integrally molded into fourth members 204. Fifth and sixth members may form a
third integrally molded grid structure 300. Reinforcement rods 1050 may be
integrally molded into sixth members 306. As shown in the exemplary embodiment
depicted in FIGS. 1, 2, 3, 4 and 5, grid structures 200 and 300 include bi-
directional
integrally molded reinforcement members forming support grids within the
members.
Because of the properties of the reinforcement members 50, further discussed
herein,
and their configuration into a bi-directional grid structure, the members in
which the
reinforcement members 50 are embedded have a relatively small size and provide
for
increased open screening area. The grid structures provide screen strength,
support
for openings 26 during vibratory loading and significantly increase open
screening
area. Although second and third grid structures are discussed herein, fewer or
additional grid structures may be provided.
First members 101 may be substantially parallel to each other and extend
transversely
between side edge portions 14, 16. The second members 102 may be substantially
parallel to each other and extend transversely between the lower edge portion
18 and
the upper edge portion 20. Second members 102 may have a thickness greater
than
the first members to provide additional structural support to screen openings
26.
First members 101 and/or second members 102 may include reinforcement members
50 and may or may not be supported by additional support members or support
grid
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structures. See, e.g., FIGS. 6 and 9. As shown in FIG. 9, body 12 has first
and
second members 101, 102 with bi-directional reinforcement members 50 molded
integrally therewith. Such configurations may be beneficial for screening
applications
requiring screens with larger screen openings.
In certain embodiments, reinforcement rods 1050 may be incorporated into at
least
one of the fourth and sixth members, 204 and 306 respectively and run from
edges 14
to 16. See., e.g. FIGS. 12 and 12A. Reinforcement rods 1050 provide stability
and
prevent hourglassing or other deformation of the screen along the edges of the
screen
without the U-shape channels, i.e., edges 14 and 16. These embodiments may
incorporate reinforcement members 50 in first, second, third, fourth, fifth
and/or sixth
members 101, 102, 203, 204, 305, 306. Reinforcement members 50 may be
incorporated into all or a portion of first, second, third, fourth, fifth
and/or sixth
members 101, 102, 203, 204, 305, 306. Reinforcement members 50 provide screen
properties as discussed herein.
As shown in FIG. 4, the screen openings 26 are elongated with a greater length
dimension along sides and between ends thereof than width dimensions between
the
sides and their length dimensions extending in a direction transverse to the
side edge
portions 14, 16. Screen openings 26 may be about .044 mm to about 4 mm in
width
(i.e., between the inner surfaces of adjacent first members 101) and about
.088 mm to
about 60 mm in length (i.e., between inner surfaces of adjacent second members
102).
Screen openings 26 may have different shapes including a generally square
shape.
The overall dimensions of screen 10 may be about 1.2 meters times 1.6 meters,
or any
other desired size. All of the dimensions set forth herein are by way of
example and
not of limitation.
Screen openings 26 may diverge downwardly between the upper surface 22 and the
lower surface 24 and the first members 101 may be substantially in the shape
of
inverted trapezoids. See, e.g., Figures 6 and 7. This general shape of the
first
members 101 prevents blinding in screens 10. As shown in Figure 6, first
members
101 include reinforcement members 50. As shown in Figure 7, first members 101
do
not include reinforcement members 50.
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Screens with the various screen opening sizes and support configurations
described
herein have a relatively large open screening areas. Open screening areas may
range,
for example, from between about 40 percent to about 46 percent. As further
discussed
herein, the relatively large open screening areas may be obtained through the
placement of bi-directional reinforcement members 50 in cross members (e.g.,
members 203, 204) as described in the various embodiments herein. The
reinforcement members significantly decrease the size of both of the bi-
directional
support cross members and allow for a thinner screen members, 101, 102 forming
the
screen openings 26. The grid work of support members and reinforcement members
provide for a structurally sound screen that maintains the necessary screen
openings
during vibratory operation.
Third and fourth members 203, 204 may have a thickness greater than the first
and
second members 101, 102 and may have a portion 210 extending downwardly below
.. the lower surface 24 of body 12. The greater thickness and portion
extending
downwardly may provide additional structural support to first and second
members
101, 102. As shown in FIG. 1B, portion 210 may be substantially triangular in
cross-
section with apexes projecting away from the lower surface 24 of body 12. The
third
members 203 may be substantially parallel and extend transversely between the
side
edge portions 14, 16 and may have multiple first members 101 therebetween. The
fourth members 204 may be substantially parallel and extend transversely
between the
lower edge portion 18 and the upper edge portion 20 and having multiple second
members 102 therebetween. Fourth members 204 may have reinforcement rods 1050
integrally molded therein. Reinforcement members 50 may be molded integrally
with
the third and fourth members 203, 204. See, e.g., FIGS. 3A, 5A. Third and
fourth
members 203, 204 may be configured to have a minimal thickness through
inclusion
of reinforcement members 50, while providing the necessary structural support
to
maintain the screen openings 26 formed by first and second members 101, 102
during
vibratory screening applications. The bi-direction support system provided by
reinforced third and fourth members 203, 204 greatly reduces the thickness of
the
support members and provides for increased open screening area and overall
screen
efficiencies. Incorporation of reinforcement rods 1050 into fourth members 204
may
adds stability to screen 10 and prevents hourglassing, i.e., deflection
inwardly of side
edges 14, 16 to give the screen a general hourglass type shape.
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Fifth members 305 and sixth members 306 may be included in body 12. Fifth and
sixth members may have a thickness greater than the third and fourth members
and
may have a portion 310 extending downwardly away from the lower surface of the
body. The greater thickness and portion extending downwardly may to provide
additional structural support to first and second members 101, 102. The sixth
members 306 may include a portion 320 extending upwardly away from the upper
surface of the body. Portion 320 may be substantially triangular in cross-
section with
apexes projecting away from the upper surface 22 of body 12. Sixth members 306
are
shown in FIG. 2 with portion 320 extending upwardly away from the upper
surface of
body 12 and acting as flow guides. Sixth members 306 may have reinforcement
rods
1050 integrally molded therein. The fifth members 305 may be substantially
parallel
and extending transversely between the side edge portions 14, 16 and have
multiple
third members 203 therebetween. The sixth members 306 may be substantially
parallel and extending transversely between the lower edge portion 18 and the
upper
edge portion 20 and have multiple fourth members 204 therebetween.
Reinforcement
members 50 may be molded integrally with fifth and sixth members 305, 306.
Fifth
and sixth members 305, 306 may be provided for additional support to screen
openings 26 and may be configured to have a minimal thickness through
inclusion of
reinforcement members 50, while providing the necessary structural support to
maintain screen openings 26 during vibratory screening applications. The bi-
direction
support system provided by reinforced fifth and sixth members 305, 306 greatly
reduces the thickness of the support members and provides for increased open
screening area and overall screen efficiencies. Incorporation of reinforcement
rods
1050 into sixth members 306 adds stability to screen 10 and prevents
hourglassing.
FIG. 1 A shows an exemplary embodiment of the present inventions having first
and
second members 101, 102 forming screen openings 26 and members 203, 204
forming a support grid structure for openings 26. As shown in FIG. 1A, screen
10
does not include fifth and sixth members 305, 306. FIGS. 12 and 12A show
another
exemplary embodiment of the present invention having reinforcement rods 1050
integrally molded therein. As shown in FIGS. 12 and 12A, reinforcement rods
1050
are integrally molded into fourth members 204. Reinforcement rods 1050 may
also
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be integrally molded into sixth members 306 or other members running parallel
to
members 204 and 306.
In use, the vibratory screen 10 is mounted on a vibratory screening machine 30
(FIG.
8) in the well known manner. More specifically, it is mounted on the screen
deck bed
31 which is mounted on the frame (not shown) of the machine. The screen deck
bed
31 includes spaced substantially parallel frame members 32 secured to each
other by
spaced substantially parallel cross frame members (not shown). Extending
transversely between the cross frame members are a plurality of substantially
parallel
stringers 33 which mount channel rubbers 34. Mounted on parallel frame members
32
are channel-shaped draw bars 35 having lower portions 36 which are received
within
side edge portions 14, 16. Draw bolts 37 draw bars 35 apart to thereby tension
vibratory screen 10 with the required force. The foregoing type of screen deck
bed is
well known in the art. Screen 10 may be mounted to other vibratory screening
machines and side edge portions 14, 16 may be configured in other shapes to
accommodate different vibratory screening machines.
The embodiment shown in FIG. 13 is mounted front to back on vibratory
screening
machine 1010. In this embodiment, angle 15 is included in upper edge 20 and
lower
edge 18 and is below top surface 22. This embodiment has tension applied from
underneath the screen rather than above and the tension is applied from front
to back.
FIG. 14 shows an embodiment having angle 15 included in side edges 18, 20.
This
embodiment also has tension applied from above the screen and from side to
side.
Reinforcement members 50 as described herein may be an aramid fiber (or
individual
filaments thereof), a naturally occurring fiber or others material having
relatively
large tensile strengths with relatively small cross sectional areas. When an
aramid
fiber is used as reinforcement fiber 50 it may be aramid fibers that are
commercially
obtainable under the trademark KEVLAR of the DuPont Company and further
identified by the designation KEVLAR 29. The reinforcement members 50 may also
be at least one of aramid fibers that are commercially obtainable under the
trademarks
TWARON, SULFRON, TEIJINCONEX, and TECHNORA of the Teijin Company.
In addition, the aramid fibers may be twisted or woven multistrand so that
they act as
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nature of wicks to absorb the polyurethane which is molded around them to
thereby
provide an extremely good bond therewith. The twisted or a woven multistrand
fibers may be about 55 denier to about 2840 denier, preferably approximately
1500
denier. The flexibility of the aramid fibers provides a flexible reinforcement
system
for the molded polyurethane which is able to return to its original molded
shape after
the necessary bending and flexing that occurs during handling and installation
into the
vibratory frame member 32. Furthermore, flexible aramid fibers permit the
flexible
polyurethane screen to be flexed without harm into an arcuate condition and
tensioned
as shown in FIGS. 8, 13 and 14. Reinforcement members 50 may be tensioned
before
polyurethane is molded around them. Various configurations of reinforcement
members 50 may be provided in any one of the first, second, third, fourth,
fifth and
sixth members 101, 102, 203, 204, 305, 306. Each member may include zero, one
or
more reinforcement members 50 and the reinforcement members 50 may be of
different sizes and materials. Reinforcement members 50 may be located in the
bottom halves of the members so as not to be exposed relatively early as the
upper
surface of the screen wears.
During operation, first members 101 will vibrate to enhance the screening
action. In
this regard, it is to be noted that because first members 101 are flexible and
relatively
thin they will provide a relatively high amplitude of desirable vibration. The
reason
the first members 101 can be made relatively thin, creating screen openings
described
herein, is because of a support framework of bi-directional support members
and
reinforcement members, as described herein, having relatively large tensile
strengths
with relatively small cross sectional areas. The making of the support members
and
the first members 101 relatively thin results in the screen having a greater
percentage
of open area, which, in turn, increases its capacity.
According to an exemplary embodiment of the present invention a vibratory
screen 10
includes a flexible molded polyurethane body 12 having substantially parallel
side
edge portions 14, 16 at opposite ends of body 12, a lower edge portion 18
substantially perpendicular to the side edge portions 14, 16, an upper edge
portion 20
substantially perpendicular to the side edge portions 14, 16 and opposite the
lower
edge portion 18, an upper surface 22, a lower surface 24, first and second
members
101, 102 forming screening openings 26, the first members 101 extending
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the side edge portions 14, 16 and the second members 102 extending between the
lower edge portion 18 and the upper edge portion 20. The body may also
includes
third and fourth members 203, 204. Third and fourth members 203 and 204 may
have
a thickness greater than the first and second members 101, 102. Third members
203
are substantially parallel and extend transversely between the side edge
portions 14,
16 and have multiple first members 101 therebetween. Fourth members 204 are
substantially parallel and extend transversely between the lower edge portion
18 and
the upper edge portion 20 and have multiple second members 102 therebetween.
Reinforcement members 50 may be molded integrally with the third and/or fourth
members 203, 204. Reinforcement rods 1050 may be molded integrally with fourth
members 204. The body also includes fifth and sixth members 305, 306. Fifth
members 305 are substantially parallel and extending transversely between the
side
edge portions 14, 16. Sixth members 306 are substantially parallel and
extending
transversely between the lower edge portion 18 and the upper edge portion 20.
The
fifth and sixth members have a thickness greater than the third and fourth
members
and include reinforcement members 50 molded integrally therewith.
Reinforcement
rods 1050 may be molded integrally with the sixth members 306. Vibratory
screens
according to this configuration may have open screening areas greater than
forty
percent and mesh sizes ranging from approximate .375 mesh to approximately 400
mesh. By way of example, screens tested having the aforementioned
configuration
include a 43 mesh size screen, a 140 mesh size screen and a 210 mesh size
screen.
Each of these screens had open screening areas of approximately 40 percent to
approximately 46 percent. Such large screening areas for such fine mesh sizes
are
achieve through the relatively strong and thin grid framework created by the
third,
fourth, fifth and sixth members, 203, 204, 305, 306 and reinforcement members
molded integrally therewith. In the aforementioned exemplary embodiment and
examples, the size of each grid unit formed by the intersection of the third
and fourth
members, 203 and 204 is approximately 1" by 1". Generally, grid units may be
larger
for screens with larger screen openings and grid units are smaller for screens
with
smaller screen openings. This principle may be generally applicable for each
example
embodiment discussed herein. Grid units may also have a generally rectangular
shape
or any other suitable shape for supporting the screen openings.
11
CA 02902782 2015-08-26
WO 2014/149516
PCT/US2014/019233
According to an exemplary embodiment of the present invention, a method of
making
a vibratory screen, includes: creating a mold configured to fabricate the
vibratory
screen, the vibratory screening having a flexible molded polyurethane body;
installing
reinforcement members in the mold, the reinforcement members configured to be
molded integrally with the body; installing reinforcement rods in the mold,
the
reinforcement rods configured to be molded integrally with the body, filling
the mold
with polyurethane; and forming the vibratory screen that has: substantially
parallel
side edge portions at opposite ends of the body, a lower edge portion
substantially
perpendicular to the side edge portions, an upper edge portion substantially
perpendicular to the side edge portions and opposite the lower edge portion,
an upper
surface, a lower surface, first and second members forming screening openings,
the
first members extending between the side edge portions and the second members
extending between the lower edge portion and the upper edge portion, third and
fourth
members ,the reinforcement rods molded integrally with at fourth members, the
third
members substantially parallel and extending transversely between the side
edge
portions and having multiple first members therebetween, the fourth members
substantially parallel and extending transversely between the lower edge
portion and
the upper edge portion and having multiple second members therebetween,
reinforcement members molded integrally with at least one of the first and
second
members.
While preferred embodiments of the present invention have been disclosed, it
will be
appreciated that it is not limited thereto but may be otherwise embodied
within the
scope of the following claims.
12
