RAISED WEARING ROD PROTECTED RUBBER SCREENING PLATES

TAMIS DE CAOUTCHOUC PROTEGE PAR DES TIGES D'USURE SE PROLONGEANT AU-DESSUS DE LA SURFACE DES TAMIS

English Abstract

ABSTRACT
A screen plate for screening ores, the screen plate
comprising a rubber screen having a plurality of apertures
therethrough, the apertures being arranged in rows
longitudinally of the screen. In order to protect the rubber
screen protective wear resistant metal bars are provided
between the rows of apertures, the bars being embedded in the
rubber screen and extending above the surface of the rubber
screen.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A screen plate for the screening of ores and the
like, the screen plate including a rubber screen having
apertures therethrough to separate the larger pieces of ore
from the pieces passing through the apertures, the screen
plate being characterised by runner bars embedded longitudi-
nally in the rubber screen and having their upper surfaces
spaced above the surface of the rubber screen whereby the
rubber screen is protected from the large pieces of ore to
be screened, upper adjacent edges of the said runner bars
being spaced closer to each other than portions of the bars
therebeneath.
2. A screen plate as defined in claim 1, wherein the
apertures are arranged in rows along the length of the screen
plate, the runner bars extending along the screen plate and
situated between each. said row of apertures and adjacent each
longitudinal edge of the screen plate.
3. A screen plate as defined in claim 1 or claim 2,
wherein the runner bars are of wear resisting metal.

Description

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This invention relates to improvements in or relating
to screen plates, and more particularly to screen plates
which are used in the mining industry for separating various
grades of ore and the like.
5. In the field of screening, particularly the screening
of ores and the like, it has been found that a rubber screen
of appropriate hardness has a very high resistance to abrasion
and it is common practice to use such rubber screens in such
screening applications. However it has been found, that in
10. use, if the material being screened has portions or p:ieces
thereof of relatively large dimension that these larger
dimension pieces tend under certain conditions to lacerate
the rubber screen. This is felt is due to the fact that these
larger portions are such that, during the screening operation,
15. due to their weight sufficient force is applied by these
pieces as they contact the screen to cut through the surface
of the screen and tend to lacerate the surface. This does
not occur with smaller sized particles and pieces due to
the fact that the pieces due to their smaller weight do not
20. have sufficient energy to cause the edges thereof to cut and
lacerate the screens.
Thus it is an object of this invention to provide a screen
which will retain the desired properties and screening effect
of the rubber screen while minimising the laceration effect of
25. the larger pieces being screened.
Thus there is provided according to one aspect of the
invention a screen plate for the screening of ores and the
like, the screen plate including a rubber screen having
2.
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1~83S33
apertures therethrough to separa-te the larger pieces of
ore from the pieces passing through the apertures, the
screen plate being characterised by runner bars embedded
longitudinally in the rubber screen and having their upper
5- surfaces spaced above the surface of the rubber screen
whereby the rubber screen is protected from the larger pieces
of or to be screened.
In order to more fully describe the invention reference
will now be made to the accompanying drawing which shows
10. a screen in perspective.
Referring to the drawing the screen plate 1 comprises
a rubber screen 2 having the holes 3 therethrough arranged
in parallel rows along and across the screen. Longitudinal
rows spacer bars 4 are provided to be upstanding from the
15. surface of the rubber screen, the bars 4 running longitudinally
of the screen plate 1.
The bars 4 are preferably formed of a material having
the appropriate abrasion resistance and for example could
be cast 15-3 white iron runner bars having a width of
20. approximately one inch at the top thereof and preferably
spaced about one inch above the surface of the rubber screen
2. The spacing apart of the metal bars, the hardness and
abrasion resistance thereof, the size and the height of the
bars above the surface can be varied depending upon the
25. particular application to which the screen is to be applied.
Thus by way of example only, the screen plate 1 could be
24" long and 12" wide, wi-th 18 holes in 3 rows of 6 holes, the
holes being 2~" by 1 3/4", the rows of holes being separated
by the runner bars.
30. Preferably the runner bars 4 are firmly attached
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3.
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83S33
or keyed into the rubber screen 2 and the bars 4 could
be moulded into the rubber screen 2 during the moulding
and manufacture of the screen and the shape of the bars
where they are embedded into the screen can be varied
5. so that the bars would be effectively keyed into the
screen. In the example shown, the bars 4 are permanently
attached to the rubber screen with the bars 4 having
an enlarged portion emhedded in the rubber screen 2.
~lternatively the bars 2 could be such that they can be
10. readily replaced, for example by being slidingly fitted
through a shaped keyway or other shaped slot in the rubber
screen 2 so that the bars can be replaced if they become
excessively worn and so prolong the life of the screen
itself.
lS. The rubber screen 2 is mounted on a metal backing
plate 5, and mounting holes 6 are provided through the
` rubber screen 2, and the backing plate 5 to allow mounting
of the screen plate 1 in position. Preferably the backing
f_~ plate 5 is a perforated mild steel backing plate. ~-
20. Preferably also the bars 4 are slightly trapezoidal
in sections, i.e. the upper surface is 1" in width, but
that the bar~ taper slightly towards the surface of the
rubber screen 2, to a width of 7/8" or 3/4", so that the
tendency of any pieces to jamb or become wedged therebetween
25. is minimized, for if-they pass between the adjacent upper
edges, then the pieces would not readily foul b~tween
the bars.
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Thus it will be seen that the bars will effectively
carry and support the largest sized pieces and particles
and will absorb the major portion of the impact of those
pieces so that the larger pieces will not due to their
5. high eneray cut and lacerate the surface of the screen
and the bars will quickly and effectively transfer the
larger pieces off the end of the screen where they can
be recycled through the crusher or the like.
Thus although one form of the invention has been
f~ 10. described in some detail it is to be realised that the
invention is not to be limited thereto but is to include
any and all variations falling within the spirit and scope
oL the invention.
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