Improvements in the Construction of Apparatus for Screening Coal or other Substances.
Year: 1895

page_text: Date of Application, 16th July, 1895
Complete Specification Left, 4th. Nov., 1895-Accepted, 7th Dec., 1895
Improvements in the Construction of Apparatus for Screening Coal
or other Substances.
We THOMAS DICKINSON SWIFT and HENRY WILLIAM SWIFT both of Ince
near Wigan, in the County of Lancaster, Engineers, do hereby declare the nature
of this invention to be as follows:-
This invention relates to the construction of the screens used for screening coal
and other substances, the object of, the invention being to provide means whereby
the mesh" of, the screens can be opened or closed so as to increase or diminish
the "size" of the coal or other material, passed through or delivered without having
to change the screens for each variation in size" as usual.
66
For, the purposes of our invention we make the rods or bars of the screen
movable, and we.mount the ends of the same in grooves in the inner sides of the
The central
top and, bottom bars of the sloping frame which supports the same.
rod or bar of the screen only is fixed, and the others are movable and capable of
sliding, in the grooves so that they can be opened out from or closed in, towards the
central fixed bar so as to increase or diminish the "mesh."
•
The central fixed rod or.. bar, is solid, and the other or movable bars have
longitudinal grooves formed in their under side. To the lower side of the central
fixed rod or bar two levers are pivotted at points about equidistant from the ends
of the rods and from each other, and these two levers are connected together
underneath the frame by two parallel, links, so that the two levers work together
in unison, and each lever is; provided with as many pins as there are loose rods or
bars, one pin of each lever working the groove at the back of each bar.
Each lever is formed at one end like a handle which projects beyond the sloping
frame one on each side.
It will therefore be evident that when these levers are at right angles to the
frame, the, movable rods or bars of the screen will all be at their furthest distance
apart from each other; thus producing a "mesh" equal to the distance apart of the
pins on the levers. But upon drawing either of the levers into a more or less
diagonal position, the parallel, links will move the other lever into a corresponding
position (the whole working after the manner of "lazy-tongs") and the movable
rods or bars will all be drawn in towards the central fixed bar, and nearer to each
other, so as to reduce the "mesh" of the screen to the required degree according
.to the amount of angle given to the levers.
Holes and pegs (or other similar device) may be used for the purpose of fixing
the levers in the position to which they have been adjusted so as to keep the screen
always at the same.".mesh" until an alteration is required.
L:
CT. 1905
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicants.

page_text: Improvements in the Construction of Apparatus for Screening Coal
or other Substances.
We THOMAS DICKINSON SWIFT and HENRY WILLIAM SWIFT, both of Ince
near, Wigan, in the County of Lancaster, Engineers, do hereby declare the nature
of this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
This invention relates to the construction of the screens used for screening coal
or other substances, the object of the invention being to provide means whereby
the "mesh" of the screens can be opened or closed so as to increase or diminish
the "size" of the coal or other material passed through or delivered without having
to change the screens for each variation in size as usual.
The nature of our said' invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the two sheets of drawings hereunto annexed and the following explanation
thereof.
;
Fig. 1 on Sheet 1 of the drawings is a front elevation and Fig. 2 a vertical
section of a screen constructed according to our improvements and Fig. 3 is a
vertical section and partial underneath view of one of the bars drawn to a larger
scale.
1.
1
I
On Sheet 2 of the drawings Fig. 4 is an elevation Fig. 5 a
plan view and
Fig. 6 a vertical section of a modification of the same.
Referring to Sheet 1 of the drawings a is the sloping frame of the screen and
b the bars.
i
For the purposes of our invention we make the rods or bars of the screen
moyable, and we mount the ends of the same in grooves or recesses c in the inner
sides of the top and bottom bars a' of the sloping frame a which supports the same.
The central rod or bar b¹ of the screen only is fixed and the others are movable
and capable of sliding in the grooves or recesses c so that they can be opened out
from or closed in towards the central fixed bar b' so as to increase or diminish
the "mesh."
J
...
The central fixed rod or bar b' is solid, and the other or movable bars b have
longitudinal grooves e formed. in their under side (see enlarged view Fig. 3). To
the lower side of the central fixed rod or bar 6 two levers ff' are pivotted at
points about equi-distant from the ends of the rods and from each other, and these
two levers ff are connected together underneath the frame a by two parallel
links so that the two levers ff work together in unisou, and each lever is
provided with as many pins has there are loose rods or bars bone pin of each
lever working in the groove e at the back of each bar.
Each lever is formed at one end like a handle which projects beyond the sloping
frame a one on each side.
:
It will therefore be evident that when these levers are at right angles to the
frame (as drawn at Fig. 1) the movable rods or bars b of the screen will all be at
their furthest distance apart from each other; thus producing a "mesh" equal to
.the distance apart of the pins on the levers. But upon drawing either of the
levers for finto a more or less diagonal position (as shown by dotted lines at
Fig. 1) the parallel links g g' will move the other lever for finto a corresponding
position (the whole working after the manner of "lazy-tongs") and the movable
rods or bars will all be drawn in towards the central fixed bar 6', and nearer to
each other, so as to reduce the "mesh" of the screen to the required degree
according to the amount of angle given to the levers ƒ ƒ³.
Holes and pegs i (or other similar device) may be used for the purpose of

page_text: fixing the levers ff' in the position to which they have been adjusted so as to
keep the screen always at the same "mesh" until an alteration is required.
The modification of our invention represented on Sheet 2 of the drawings shows
how the same principle of the "lazy-tongs" levers may be applied to the screens
without grooving the backs of the bars 6. In this case the lazy tongs levers ff"
are both mounted on the same pivot attached to the central fixed bar and are
worked by a sliding bark attached to the levers by links g g'. Each bar bis
mounted in a swivel turning loosely on a pin which passes vertically through the
bars so that as the said levers are caused to assume the position shown by
dotted lines xx at Fig. 5 the bars 6 will be caused to be drawn nearer together
and to approach the central fixed bar bin precisely the same manner as in the
previously described modification.
:
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
In apparatus for screening coal or other substances the combination with the
screen frame of sliding bars connected by pivots to "lazytongs" levers pivotted to
a central fixed bar in such a way that by altering the angle of such levers the
said sliding bars may be caused to approach to or recede from the central fixed
bar, and to or from each other, so as to alter the "mesh of such bars without.
removing the screen from the sloping frame on which it is supported.
Dated this 1st dov of Nonamhor 1905
"
GEO. DAVIES & SON.