IMPROVEMENTS IN SCREENS FOR SIFTING CEMENT AND OTHER MATTERS REQUIRING TO BE SIFTED
Year: 1884

page_text: I ARTHUR GLOVER Manager to Messrs J. B. White & Bro' Limited Cement
Manufacturers of Galley Hill House Swanscombe in the County of Kent do
hereby declare the nature of my invention for "IMPROVEMENTS IN SCREENS FOR
SIFTING CEMENT AND OTHER MATTERS REQUIRING TO BE SIFTED" to be as
follows:-
This invention has for its object improvements in screens for sifting cement and
other matters requiring to be sifted.
The improved screen may be constructed of panels or frames covered with woven.
wire or other suitable reticulate material.
It may conveniently consist of four similar panels each rectangular in form
and meeting at right angles; in this case the screen is square in transverse section.
The screen revolves about a longitudinal axis in such manner that its movement.
is eccentric the axis of motion not coinciding with the centre line of the screen.
The result is a movement of the material within the screen which is very.
favourable to the rapid delivery of the finer particles through the apertures in the.
woven wire or screening material and the delivery of the larger particles at the
end of the screen.
To keep the apertures from becoming filled I mount metal rods on the panels
outside the screen; these rods serve as guides for small weights sliding upon them
and during the rotation of the screen the weights fall from end to end of the guide
rods thereby imparting to the panels or frames a series of impacts sufficient to
cause any adhering material to become detached, and fall away leaving the
perforations clear....... i
In
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page_text: I, ARTHUR GLOVER; Manager to Messrs J. B. White & Bros Limited, Cement
Manufacturers of Galley Hill House Swanscombe in the County of Kent do
hereby declare the nature of my invention for "IMPROVEMENTS IN SCREENS FOR
" and in what
SIFTING CEMENT AND OTHER MATTERS REQUIRING TO BE SIFTED
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
This invention has for its object improvements in screens for sifting cement and
other matters requiring to be sifted.
The improved screen may be constructed of panels or frames, covered with woven
wire or other suitable reticulate material.
It may conveniently consist of four similar panels each rectangular in form and
meeting at right angles; in this case the screen is square in transverse section.
The screen revolves about a longitudinal axis in such manner that its movement.
is eccentric the axis of motion not coinciding with the centre line of the screen.
The result is a movement of the material within the screen which is very
favourable to the rapid delivery of the finer particles through the apertures in the
woven wire or screening material and the delivery of the larger particles at the end
of the screen.
To keep the apertures from becoming, filled I mount metal rods on the panels
outside the screen; these rods serve as guides for small weights sliding upon them
and during the rotation of the screen the weights fall from end to end of the guide
rods thereby imparting to the panels or frames a series of impacts sufficient to
cause any adhering material to become detached and fall away leaving. the
perforations clear.
In order that my said invention may be most fully understood and readily
carried into effect I will proceed to describe the drawings hereunto annexed:
.
DESCRIPTION OF THE DRAWINGS..
Figure 1 is a plan and Figure 2 is a transverse section of a screen constructed in
accordance with my invention.
Figure 3 is a portion of a longitudinal section showing the hopper at the entrance
end of the screen.
Figure 4 shows a detail relating to the construction of the frame of the screen
drum.
A, A is a casing of wood or other material, it contains the screen drum and
supports the axis on which this is mounted.
B, B is the axis, it is carried in bearings at the ends of the casing A, A. C is a
pulley upon the axis, receiving a belt by which the axis is driven.
D is the screen drum, it is preferably square, but it may be of other polygonal or
angular form. It is mounted eccentrically upon the axis B, the axis passing

page_text: through iron diagonals d, d, with which the screen drum is furnished. The axis
is thus at a distance from the centre line of the screen body and it is parallel to it.
. The framing of the drum, which may be of wood or iron (wood is indicated in
the figures 1, 2 and 3) is formed to receive panels d¹, ď³, in which the woven wire
or other screening material is fixed. It is convenient that these panels should be
so arranged that they may be readily changed for others containing a screening
material of a different gauze to suit the work which is required to be done. E is a
hopper at one end of the screen, by which the ground cement or material to be
sifted is supplied to the interior of the screen body.
The apparatus is set at a small inclination which is capable of adjustment so that
the material within the screen body has a tendency, to travel from the entrance to
the exit end. The particles of cement or material which are sufficiently fine pass
through the screen panels and fall to the bottom casing A, and they escape by a
slit or opening a extending from end to end of the bottom of the casing.
Conveniently the ground material may then be received by an Archimedean screw
which conveys it away to any place where it may be required. The portions which
are not sufficiently finely ground issue at the end of the screen body where they in
a similar way fall down to the bottom casing and issue by an orifice. These
particles which require re-grinding may be conveyed away by a transverse
horizontal screw or in any other convenient manner.
b is a disc fixed upon the axis B to separate the ground material from that which
is not sufficiently reduced; and there are also inclines on either side of this disc
and at the bottom of the casing A to render this separation complete. d², d², are
rods fixed upon the panels of the screen, and on these small weights d³ d³ slide.
As the screen body revolves the weights pass from end to end of the rods and
strike at either end of their course upon small shelves d', d*, fixed upon the panels
to receive them. The tremor which the falling of these weights imparts to the
screen panels is sufficient to prevent the meshes from becoming choked. The
weights may be placed within the screen body.
When I make the screen body with an iron frame I prefer to employ longitudinal
irons Z form in section, as indicated at Figure 4. Into the recesses of these
longitudinal irons the screen panels d' d' are received and secured by screws.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. A square polygonal or angular screen mounted upon an axis parallel to but
not coinciding with the centre line of the screen, receiving at one end the material
to be sifted, allowing the finer particles to pass through and discharging the coarse
particles at the further end substantially as described.
2. I also claim the combination with an eccentrically mounted polygonal or
angular screen of weights d³ ³, which, as the screen rotates are alternately raised
and dropped, and which are thereby caused to impart a tremor to the screen
preventing the meshes from becoming choked substantially as described.