Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ELASTOMER SCREEN UNITS FOR SHAKER-SCREEN BODIES
BACKGROUND OF THE INVENTION
For many decades separation, classification, sifting
and dewatering of fragmented stocks of hard material such as
crushed rock, aggregate, coal, sand and the like have been
accomplished by shaker screen boxes having screen bodies made up
either of coarse-woven steel or other metal netting, or of
relatively thin sheet metal material provided with sieve open-
ings arranged in predetermined sequence or manner. The abrasion
and wear from hard material striking the charging surfaces of
such screens, as well as the impact, tumbling and flow of hard
material on such surfaces, has caused rather rapid deterioration
of the metal material. Further, corrosion and deformation of
the material from impact has shortened the life of such screens.
The din and noise from the charging of such screens and the
bouncing and tumbling of hard material thereon have been a
source of noise pollution. In the last fifteen years several
efforts have been made to lengthen the life of such metal
screens by applying coatings of somewhat flexible elastic or
elastomer material and in several instances whole screen bodies
or sections of screen bodies involving a multiplicity of ~izing
apertures have been employed. Some of the~e h~ve been supported
and reinforced by an underlying mesh of steel, wire~ or the
equivalent. Complicated molding processes have been required
for such prior art shaker screens and because the manufacturer
is requir-d to make and have available screens having mesh sizes,
sometimes square, sometimes round, sometimes elongate, and in
as many as a hundred sizes, the investment or original cost of
such processing, and in many instances the mold has been
extremely high and prohibitive. Some prior structures have
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employed laminations of plastic or elastic sheets vulcanized to
metal sheets and some have employed two or more plies of elast-
omer sheets of large size, properly punched or apertured for the
sizing required.
It is a main object of the instant invention to provide ~ ~ ;
an inexpensive, highly efficient elastomer, sectional screen
unit readily connectablé with a multiplicity of such units in
directions both longitudinally and transversely of the direction
of flow of fragmented, hardstock materials to constitute collec-
tively a full shaker screen. The embodiments of this invention
are particularly adapted for sizing, sifting and dewatering
fragmented hard-stock materials of the smaller sizes and prefer-
ably each unit is constructed integrally to provide a substantial
number of sizing apertures with a minimal requirement of inter-
vening solid material. With the employment of my invention,
substantial economy is achieved in the original installation and
in the cost of machinery or apparatus for either molding or die-
cutting of the novel sectional units, as contrasted with the
production of any known prior art sectional units.
One form of this invention is disclosed and illustrated
in my United States Patent No. 3,943,054 issued March 9, 1976.
Additional embodiments of the invention are herein disclosed and
illustrated which prov$de for more efficient and simple inter-
connection of a multiplicity of the screen units and minimize
mounting and support of ths units while still affording screen
hinge action of the independent units when interconnected with
other units of the complete shaker screen.
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- SUMMARY OF THE INVENTION
As previously stated, the sectional screen units of
this invention connected in multiplicity are particularly
adapted for sizing and sifting fragmented, hard-stock materials
of the smaller sizes. The body of each unit is preferably
integrally formed from suitable elastomer material, molded,
die-cut or otherwise formed in a generally rectangular shaped
body having a multiplicity of sorting apertures. First and
second edges of the unit extend transversely to the direction
of flow of material to be screened, and are complemental in
shape to facilitate interconnections with other units of the
sorting screen. Thus, for example, either of the described
transversely extending edges may be defined by rather closely
spaced T-head formation elements while the remaining transverse
edge is defined by substantially straight-spaced stem portions
for closely fitting between the ends of the T-head elements of
an adjacent connected unit. Also, the lateral or right and
left hand edges of each unit are preferably formed of comple-
mental shape so that when joined together transversely of the
direction of flow of material over the multi-sectional screen,
units may be supported upon a minimal number of rods or support-
ing wires and will at their junctures orm sorting apertures
with the requirement of minimal material to define such aper-
tures.
The apertured screen unit utilizes transverse integral
elastomer bar segments extending transversely to the direction~ abl
of material flow and longitudinal extending bar segments which
taper in cross section from the upper or chaxging surface of
the unit to the underside thereof and are perpendicular to the
transverse bar segments. Certain series of the longitudinally
extending bar segments are transversely apertured in alignment
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to receive and embed transversely extending supporting and
positioning rods or wires which of course are interconnected
with and supported from the frame on which the overall shaker
screen is mounted.
In the preferred forms of my inveDtion the multi-
plicity of sectional screen units is not only supported but
interconnected and secured in place to constitute a full shaker
screen by the conventional transverse supporting rods or wires.
No vulcanizing between units, clips or other connection means,
is necessary.
Great economy in the original installation costs of
the machinery or molds for producing screen bodies is achieved
with the use of my invention, since only one comparatively
small set of molds or dies is required for one sectional unit.
This is of great importance to a manufacturer when so many
different dimensional meshes of screen are required for commer-
` cial sale.
The screen units, if impaired or und~ly worn, are
quickly replaceable as described hereafter in the specification,
without removal of other units from the supporting wires or
rods.
BRIEF DESCRIPTION OF THE DRAWINGS ;
The following desoription made in connection with the
accompanying drawings will more clearly disclose details,
construction, operations and new results obtained from my
invention. In said drawings:
Fig. 1 is a top plan view of an integral, complete
section or unit of a very satisfactory embodiment of my
invention;
Fig. 2 is a right end elevation of the same;
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Fig. 3 is a cross section taken along the line 3-3 of
Fig. l;
Fig. 4 is a cross section taken along the transverse
section line 4-4 of Fig. 1 on a larger scale;
Fig. 5 is a plan view showing a plurality of said
section units joined together and secured and supported upon a
series of transversely anchored rods or stiff wires and illus-
trating how in multiple my units constitute a full body or
screen bottom for use in shaker boxes and the like;
Fig. 6 is a plan view of another embodiment of the
invention and is substantially identical to Fig. 6 in my United
States Patent No. 3,943,054.
Fig. 7 is a cross section taken on the line 7-7 of
Fig. 6;
Fig. 8 i~ a plan view of another embodiment of the
i~ invention wherein the section is of a scxeen unit having differ-
ently shaped and somewhat differently cross sectionally formed
sorting apertures;
Fig. 9 is a cross section taken on the line 9-9 of
Fig. 8; and
Fig. 10 is a top plan view of a slightly differenk
form of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the embodiment of the invention
illustrated in Fig. 1 to 5 inclusive, a sectional screen unit
indicated as an entirety by the letter U is molded, die-cut or
otherwise prepared in unitary form from a body of suitable
elastomer material. Such exem~lary plastic materials as styro-
butadiene, carboxylated nitriles or polyurethane may be ~uccess-
fully employed. Rubber elastomers such as natural or synthetic
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rubber may also be successfully used for fulfilling the purposes
and results of my invention.
The central transverse rows and proportions of the
unit U in Fig. 1 have rectangular sorting apertures A of
rectangular shape, staggered as shown in Figs. 1 and 2, although
in other forms of the invention they may be placed in line with
one another longitudinally parallel to the direction of the
flow of the hard particulate material upon the screen. In the
formation of these apertures, the material is molded or other-
~' wise formed to taper downwardly from the upper surface of the
unit, toward the lower surface gradually increasing in cross-
sectional area, thus facilitating penetration of particles -
which are of a size to go through the uppermost or charging
surface of the unit. Such tapering is indicated partially in
dotted lines in Fig. 2 and in full lines in Figs. 3 and 4. The -
unit U is provided with first and second edges extending trans-
versely to the direction of flow. The second edge of the
sectional unit U is defined by outward projecting T-shaped
connection elements T which have enlargements in the form of
thickened T-heads apertured in alignment transversely of the
entire unit by bores 10 to snugly receive positioning and
support rods or heavy wires W as shown in Fig. 5. The opposite
or first edge of the sectional unit U is defined by elongate,
straight bars or projecting elements 12 which are sufficient in
length to form sieving or sorting apertures of equal size to
the apertures in the central rows identified as ~, and to
further extend outwardly to form side flattened connection
portions 13 for interposition between the T-head portions T of
the next successive unit to be joined in the direction of flow
of the material to be sized or sifted. The outermost flattened
ends 13 of said portions 12 for each unit are provided with
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transverse bores 14 which are in alignment transversely of the
section and which are adapted to be aligned with the T-head
portions T of the next successive unit joined s shown in Fig.
5 and interconnected by one of the positioning and supporting
wires W which, of course, are employed in çombinative operation
with the units to constitute my invention.
The left and right hand lateral edges of the section-
al unit U extend generally parallel to the direc~ion of flow
and are complementary shaped so that a pair of the units may be
joined transversely of the flow direction to continue the exact
rectangular or other aperture shape of the units, and of course
are joined together by the common rods or heavy wires W.
Preferably rods or stiff wires W extending trans-
versely to the flow direction and supported from the sides of
the shaker box are employed only in the transverse intercon-
nection of the several units and thus provide for independent
hinge action of the separate units. This is of substantial
- importance in providing yieldability on the original impact of
the hard, particulate material upon the charging upper surface
of the multi-sectional screen, and also mitigates and cushions
tumbling action during the travel of the hard material down-
wardly in the flow over the screen. It will be understood that
additional supporting and positioning wires may be employed
through other suitable transversely aligned bores for screens
for larger particles and for heavier fragments of crushed
material.
When a multiplicity of said units are joined together
as shown in Fig. 5, the sizing or sorting apertures are uniform
throughout the entire screen body, and an important feature is
that a very minimal amount of solid material is employed to
define the great multiplicity of sorting apertures.
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From the foregoing description it will be seen that
the entire shaker screen bodies or bottoms with a great variety
of large dimensions may be made from my sectional unit structure
supported and positioned simply upon transverse rods or wires
common to the interconnected screen units. The sectional,
apertured, unit enables capital costs for manufacture of a large
variety of overall screen bodies of different size mesh to be
-~ very economically accomplished. Only one, relatively small and
inexpensive mold or die for each mesh size is required with my
improved construction. ~-
A SECOND EMBODIMENT
In Figs. 6 and 7 of he drawings another embodiment of
~ my invention is illustrated and as shown, the sizing apertures -
- are of larger mesh than the form first described.
Here an apertured screen unit S is produced, prefer- -
ably by molding, having the staggered, rectangular longitudinal
rows of sorting apertures O. The overall configuration is quite
similar to the form first described and illustrated in Figs. 1
to 5 inclusive.
Solid, narrow portions of the screen unit S comprise
longitudinal bar segments 20 extending in the direction of flow
of the material to be sized, together with transverse bar seg-
ments 21. Both bar segments are slightly tapered from their
upper charging surface to their lower surface. This facilitates
classifying of "through" size particles.
Unit S is preferably integrally molded or cast from a
desirable elastomer material with the requisite number of trans-
verse supporting wire-receiving bores cored or otherwise formed
therein. Wires W may be embedded in the molds if two-part molds
are used, and in such instance will have connection elements at
their extremities for juncture with abutting screen units of
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similar structure. In fabricating a full screen body a multi-
plicity of the units S are vulcanized or otherwise secured and
integrated along abutting edges.
In this form of the invention it will again be seen
that flexibility and hinging of some of the elastomer material
along the many wire reinforcing lines occuxs during the charg-
ing, the vibration, and operation of this form of my invention.
A THIRD EMBODIMENT
In Fig. 10, a top plan view, I illustrate a third
embodiment of the invention, particularly adapted for classifi-
cation or sifting of hard particle material which is slivery in
nature. Again, an apertured, screen unit with a body construct-
ed of suitable elastomer material is employed, indicated as an
entirety by U-3. This body has a plurality of vertically
aligned series of elongate, narrow sorting apertures 31. The
apertures are defined by edges which taper, as disclosed in the
previous forms of the invention.
A single mold or die of relatively small proportions
may be utilized to form the unit which has first and second
generally transverse edges as described hereafter.
The transverse second edge of the unit is provided
with relatively wide outwardly pro~ecting elements or tongue
portions 32 integrally formed with the body which along the
general transverse second edge of the unit are spaced apart by
rectangularly notched recesses 32a. These tongues have aligned
bores 33 formed therein for receiving ~he rods or wiring for
joining a multiplicity of the units and supporting the same in
the proper operative position. The left hand and right hand
ends of the series of tongues 32 are indented slightly inward
from the lateral edges of the unit.
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At the first edge of the unit, outwardly projecting ~ -
elements or tongue members 34 are spaced apart in proper
relation and dimensioned to be interposed in the joining of two
units longitudinally of the flow direction in recesses 32a
provided in the second edge of an adjacent to-be joined unit. -
These tongue members 34 are provided with aligned, transverse
bores 36 for reception of the supporting wires or rods pre-
viously referred to. The end members abutting the lateral edges
are of approximately half the width of the tongue member 34 and
are identified as 35. These narrower end tongue members inter-
fit with the recesses formed at the extreme side portions of
; the second edge of the unit.
A FOURTH EMBODIMENT
.. . . . .: .
Fig. 8 shows a plan view of a still further embodi-
ment of the invention, having essentially all of the important
characteristics and components of the form first described and
illustrated in Figs. 1 to 5 of the drawings. In this form the
unit as an entirety is designated as U-4 and is provided with
staggered rows of circular sizing or sorting apertures 41 which
are tapered from the lower surface of the screen unit to the
uppér or charging surface, aQ is in aommon with the other forms
of the invention. The section is formed of a body of elastomer
material having first and second transverse edges. The second
edge is defined by a plurality of outwardly projecting elements
or tongue portions 42, all of equal size and shape, and having
transverse aligned bores 43 formed therethrough to accommodate
heavy wires or rods for the connection transversely of a plural-
ity of the units and for support of the units in operative
position.
The first edge of the unit U-4 is provided with a
similar plurality of outwardly projecting elements or narrow
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tongue members 44 which are spaced apart and are ad,apted to be interposed
between the tongue portions 42 of a second unit interconnected in longitu-
dinal arrangement in line of the flow of material over the screen.
The side or lateral edges of the unit U-4 are similar in shape to
cooperate in the joining of units transversely of the overall screen body
formed to continue without additional need for material, the staggered
series of sizing apertures.
In all forms of my invention, any of the sectional units may be
readily removed from the overall screen body and replaced without dis-
connecting the transverse interconnecting and supporting rods. To removea unit the unit is transversely sliced directly over both supporting rods
or wires. Any sharp cutting medium, such as a small rotary saw or a sharp
knife, may be employed for such cutting. The unit is thereafter pushed
downwardly into the bottom of the shaker box or trough and removed. The
new replacement unit is transversely cut or sliced along appropriate trans-
verse lines through its underside so that the slices or grooves formed
intersect with the upper and lower transverse wire-receiving bores. There-
after the new sliced unit may be forced downwardly upon the appropriate
transverse rods and thus becomes interconnected with the other units and
' 20 supported in the precise position of the worn or damaged unit replaced.
From the foregoing description and the accompanying drawings,
it should be apparent that the important advantages and new results
achieved by the invention are essentially as follows:
1. Sectional elastomer units readily connectible in multiplicity
for entire screen bodies may be very economically produced to provide
entire screen bodies for shaker screens and the like, where the overall
areas of the screens vary widely in dimensions and areas.
2. The sectional units with complemental first and second edges re- ~'~
j, quire for interconnection and support only a minimal number of transverse
wires or rods secured conventionally to the sides of the shaker box or
trough.
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