FIELD OF THE INVENTION:
This Invention relates to an improved screening device.
This invention more particularly relates to an improved screening device having
additional components (rider bars) on its top surface for screen mineral ores in
mines, steel plants and other processing plants.
BACKGROUND OF THE INVENTION:
Screen decks are used for screening mineral ores in mines, steel plants and other
processing plants. However, the screen decks are subject to wear and tear and
therefore as decks are made of rubber or polyurethane, the life of such decks is
limited. The need exists to increase the life of the screen decks made of rubber or
polyurethane as well as help in better stratification and thereby better screening
without adding much weight to the screen element.
The United States patent application US2002/000399, describes a screen assembly
for vibratory separators.
The international publication refers to WO/2001/45867_discloses a panel having rider
bars arranged in side by side relationship and which have a curved head.
OBJECTS OF THE INVENTION:
It is therefore an object of this Invention to propose an improved screening device
having an additional component (rider bar) on its top which increases the life of the
screen panel.
It is a further object of this invention is to propose an improved screening device
which improves the stratification.
Another object of this invention is to propose an improved screening device, which
ensures a better screening than hitherto possible.
SUMMARY OF THE INVENTION
Accordingly the present invention provides a screening device suitable for screening
mineral ores, comprising screen panel with a top surface having screen openings and
solid portions, said screen openings being separated by said solid portions, and at
least one of said solid portions being provided with a rider bar, said rider bars being

arranged between adjacent screen openings, and along the longitudinal direction of
the top surface characterized in that said rider bar has a wider base on said solid
portions and an uniformly tapering top surface and said rider bars are made of
rubber or polyurethane; and inserts made of a wear resistance material are
incorporated inside said rider bars in order to strengthen the rider bars.
In accordance with preferred embodiments of the screening device;
- said rider bars are continuous or discreet and are held to the screen panel (A) by
bonding, sliding or push-fitting.
- the rider bars are made of rubber, polyurethane with ceramic or hardox or both
ceramic and hardox impregnated in it.
- the inserts are made from wear resistant material such as hardox and ceramic,
singly or combination.
- the inserts are discreet or continuous.
- an extension, is provided at the bottom of the rider bar for slide fit.
- rider bars have a trapezoidal cross section.
- said inserts extend from said uniformly tapering top surface to a cavity inside a
solid portion of the screen panel.
BRIEF DESCRIPTION OF THE INVENTION ACCOMPANYING DRAWINGS:
The Invention will now be explained with the help of the accompanying drawings
where Figure 1 shows a known screen surface.
Figures 2 to 5 show four different embodiments of the screen having four different
types of rider bars on the top surface of the screen.
DETAILED DESCRIPTION OF THE INVENTION:
Referring to Figure 1 the screen panel A, comprises a top surface (1), an
aperture/hole (2) which allows the material to pass through for separation and the
apertures are separated by gaps (3). Generally, the top surface (1) is flat or level
surface and is made of rubber or polyurethane material. In accordance with the

invention, projections (4) (Figure 2) are added on the gap (3) between the apertures
(2). It is possible to have any shape of the projection, i.e. regular or irregular, and in
a preferred embodiment it is trapezoidal in shape.
In accordance with the invention, figures 2 to 5 exhibit four different kinds of rider
bars mounted on the screen.
Referring to figure no 2, it will be seen that it shows an isometric view of the screen
with one type of rider bar, this screen has the usual top surface (1),
apertures/holes/screen openings (2) and the usual solid portions (3).
In addition, there is provided a rider bar (4), (also called a projection) on a solid
portion (3) of the screen extending longitudinally to the entire length of the screen or
as may be required. Thus there can be one rider bar on each of the solid portion or
on selected solid portions as may be considered necessary.
"For efficient operations, these bars have a wider base (4A) and an uniformly
tapering top surface (4B) / {preferably, removably provided on the solid portions (3)
between the apertures (2). It is possible to have any shape of the projection ^ rider
bar) i.e. regular or irregular, and in a preferred embodiment it is trapezoidal in
shape.
Figure no 3 shows another embodiment where there is provided an insert (5) from
the top surface of the rider extending into a cavity (6) in the solid portion (3) of the
screen.
The insert may be continuous along the length of the rider bar or can be discreet
cylindrical pieces incorporated into the rider bar. These projections or rider bars can
be integrally bonded onto to solid surface of the screen or removably fitted.
Figure no 4 shows a dove tailed extension (7) at the bottom surface of the bar
extending into a corresponding cavity, ([delta])
Figure no 5 shows another embodiment where there is provided a different type of
extension (9) at the bottom surface of the bar extending into a cavity (10)
The rider bar may be manufactured as a single element by moulding with the screen
panel, or it is manufactured as a separate unit which is replaceable. A replaceable
unit is advantageous in that in the event that the rider bar is damaged, the entire

panel need not be replaced or repaired. This saves on costs and also increases the
life of the panel considerably.
Thus according to this invention is provided a rider bar for a screening device,
comprising a panel with projections along the longitudinal direction, said projections
being continuous or discreet and fixed to the base by bonding, sliding or push-fitting.
The life of the screen decks made of rubber or polyurethane may be increased and
therein screening efficiency improved without adding much weight to the screen
element. This is achieved by adding projections in the panel between the apertures
to a predetermined height. These projections can be made of the same material as
that of the apertures or different materials impregnated in the base material of
constructions of the panel. The projections may be made of materials such as
rubber, polyurethane or even more wear resistant material like hardox, ceramic, to
increase the life of the portion which is most wear prone.
The projections can be along the flow or across the flow of the material on the screen
panel, the projections on the rider bars may be of any shape, i.e. rectangular
section, semicircular, trapezoidal, S shaped, running straight or Zig Zag etc.
The different combinations of the base and projections may be polyurethane over
polyurethane panels, rubber over rubber panels.
In accordance with a preferred embodiment, the rider bars may be further
strengthened by incorporating inserts therein, made of wear resistant materials such
as hardox, ceramic. The preferred combinations are hardox impregnated into
polyurethane or rubber projections or ceramic impregnated into polyurethane or
rubber projections or both hardox and ceramic embedded together in the rider bar.
A replaceable unit is advantageous in that in the event that the projecting rider bar is
damaged, the entire panel need not be replaced or repaired. This saves on costs,
and also increases the life of the panel considerably.
The present invention has been described with reference to some non limiting
preferred embodiments and drawings for the sake understanding and it includes all
legitimate developments within the ambit of what has been described hereinbefore
and claimed in the appended claims.

WE CLAIM :
1. A screening device suitable for screening mineral ores, comprising :-
a screen panel (A) with a top surface (1) having screen openings (2) and solid
portions (3), said screen openings (2) being separated by said solid portions (3),
and at least one of said solid portions (3) being provided with a rider bar (4), said
rider bars (4) being arranged between adjacent screen openings (2), and along the
longitudinal direction of the top surface (1) characterized in that said rider bar (4)
has a wider base (4A) on said solid portions and an uniformly tapering top surface
(4B) and said rider bars (4) are made of rubber or polyurethane; and inserts (5)
made of a wear resistance material are incorporated inside said rider bars (4) in
order to strengthen the rider bars (4).
2. The screening device as claimed in claim 1 wherein said rider bars (4) are
continuous or discreet and are held to the screen panel (A) by bonding, sliding or
push-fitting.
3. The screening device as claimed in claim 1 wherein the rider bars (4) are made of
rubber, polyurethane with ceramic or hardox or both ceramic and hardox
impregnated in it.
4. The screening device as claimed in claim 1 wherein the inserts are made from
wear resistant material such as hardox and ceramic, singly or combination.
5. The screening device as claimed in claim 4 wherein the inserts are discreet or
continuous.
6. The screening device as claimed in claim 1 wherein an extension (7), is provided
at the bottom of the rider bar for slide fit.
7. The screening device as claimed in claim 1 to 6 wherein rider bars (4) have a
trapezoidal cross section.
8. The screening device as claimed in claim 1 wherein said inserts (5) extend from
said uniformly tapering top surface (4B) to a cavity (6) inside a solid portion (3) of
the screen panel

A screening device suitable for screening mineral ores, comprising :-
a screen panel (A) with a top surface (1) having screen openings (2) and solid
portions (3), said screen openings (2) being separated by said solid portions (3), and
at least one of said solid portions (3) being provided with a rider bar (4), said rider
bars (4) being arranged between adjacent screen openings (2), and along the
longitudinal direction of the top surface (1) characterized in that said rider bar (4)
has a wider base (4A) on said solid portions and an uniformly tapering top surface
(4B) and said rider bars (4) are made of rubber or polyurethane; and inserts made
of a wear resistance material are incorporated inside said rider bars (4) in order to
strengthen the rider bars (4).