aprovement in Screening Drums for Sizing Coal and other
Year: 1888

page_text: Date of Application, 28th Apr., 1888
Complete Specification Left, 7th Nov., 1888
Complete Specification Accepted, 7th Dec., 1888
[Communicated from abroad by JULIUS BARTSCH, Engineer, of 36, Grussauer Strasse,
Gottesberg, in Schlesien, in the German Empire.]
aprovement in Screening Drums for Sizing Coal and other
I, JOHN IMRAY of No. 28 Southampton Buildings, Chancery Lane in the County
of Middlesex, Consulting Engineer and Patent Agent do hereby declare the nature of
this invention to be as follows:-
My invention relates to screening drums for sizing coal and other materials, so
arranged that the smaller fragments or finer particles before they are delivered
pass through a longer course than the larger or coarser pieces, which pass through
a comparatively short course to be discharged. For this purpose the drum is con-
structed with a number of concentric circular screens all revolving together on one
axis. The innermost screen has the largest meshes, the outermost has the smallest
meshes, and the intermediate screens have meshes diminishing by steps from the
The
large meshes of the inner screen towards the small meshes of the outer screen.
coal or other material to be sized being fed at one end into the central part of the
drum, the largest pieces which do not pass through the largest meshes of the inner
screen are discharged at the other end, fragments of somewhat smaller size are
discharged from the annular space between the inner screen and the next, and so on,
until from the outermost screen the smallest fragments or particles are discharged.
The drum is preferably made to taper from the smaller or feeding end to a larger
size at the discharge end. The concentric screens of which it is made up are all
held on radial bolts with tubular distance pieces between them, so that segments can
be readily taken off for repair or replacement.
1
0011 1
CA 1000
ABEL & IMRAY,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improvement in Screening Drums for Sizing Coal and other
Materials.
I, JOHN IMRAY of No. 28 Southampton Buildings Chancery Lane in the County
of Middlesex Consulting Engineer and Patent Agent do hereby declare the nature
of this invention and in what manner the same is to be performed to be parti-
cularly described and ascertained in and by the following statement:—
.
રી
This invention relates to screening drums for sizing coal and other materials, so
arranged that the smaller fragments or finer particles before they are delivered pass
through a longer course than the larger or coarser pieces which pass through
comparatively short course to be discharged. For this purpose the drum is con-
structed with a number of concentric circular screens all revolving together on one
axis. The innermost screen has the largest meshes, the outermost has the smallest
meshes, and the intermediate screens have meshes diminishing by steps from the large
meshes of the inner screen towards the small meshes of the outer screen. The coal
or other material to be sized being fed at one end into the central part of the
drum, the largest pieces which do not pass through the largest meshes of the inner
screen are discharged at the other end, fragments of somewhat smaller size are
discharged from the aunular space between the inner screen and the next, and so on,
until from the outermost screen the smallest. fragments or particles are discharged.
The drum is preferably made to taper from the smaller or feeding end to a larger size
at the discharge end. The concentric screens of which it is made up are all held on
radial bolts with tubular distance pieces between them, so that segments can be
readily taken off for repair or replacement.
Fig. 1 of the accompanying drawings is a longitudinal section and Fig. 2 is a
transverse section of a screening drum according to this invention arranged with 5
concentric screens. Ou the shaft A are fixed several bosses B from which project
arms C which may be screwed into the bosses and secured by lock nuts as shewn.
The outer part of each of the arms C is screw threaded and enclosed in pieces of
tube D and washers placed as distance pieces in the intervals between the successive
circular screens, these being all tightened in position by screwing up the nuts E.
The material to be screened is introduced at the feeding mouth F; the largest pieces
are discharged at the end G of the innermost screen; those pieces which pass through
its meshes but which cannot pass through the meshes of the second screen are
discharged at H, and so on, the smallest pieces being discharged outside the outer-
most screen. In order to facilitate the forward travel and discharge of the material
the screens are preferably tapered as shewn. Obviously the number of concentric.
screens may be varied according to the number of sizes into which it is desired to
separate the material operated on.

page_text: The screens are conveniently made in separate segments, so that by unscrewing
some of the nuts E one or more of the outer segments can be removed to give access
for repairing or replacing some of the inner segments.
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 :-
A screening drum for sizing coal and other materials consisting of a number of
concentric circular screens on one shaft these screens having meshes diminishing
successively from the innermost outwards, substantially as and for the purpose herein
set forth.
ABEL & IMRAY,
Agents for the Applicant.