IMPROVEMENTS IN APPARATUS FOR SCREENING COAL AND OTHER MATTERS OR SUBSTANCES, PARTLY APPLICABLE TO STEAM GENERATOR AND OTHER FURNACES
Year: 1877

page_text: LETTERS PATENT to James Landless, of Nelson, in the County of Lancaster,
Engineer, for the Invention of "IMPROVEMENTS IN APPARATUS FOR SCREENING
COAL AND OTHER MATTERS OR SUBSTANCES, PARTLY APPLICABLE TO STEAM
GENERATOR AND OTHER FURNACES.”
Sealed the 20th October 1877, and dated the 26th April 1877.
PROVISIONAL SPECIFICATION left by the said James Landless at the Office
of the Commissioners of Patents on the 26th April 1877.
JAMES LANDLESS, of Nelson, in the County of Lancaster, Engineer. "IMPROVE-
MENTS IN APPARATUS FOR SCREENING COAL AND OTHER MATTERS OR SUBSTANCES,
PARTLY APPLICABLE TO STEAM GENERATOR AND OTHER FURNACES."
My Invention relates in the first place to apparatus adapted more particularly to.
be employed in the screening of coal.
In screens, as ordinarily constructed, the coal is tipped upon the higher end of a
screen, which is arranged at such an angle as that the coal will run quickly down
the screen, the slack and small coal passing between the bars of the screen. As the
coal rushes down the screen with an increasing velocity the coal becomes broken to
some extent in the screening operation, and the object of my Invention is to remedy
this defect. To this end I arrange the screen at such an angle as that the coal will
not, by reason only of its own gravity, run down the screen from one end to the
other, and I assist the downward progress by imparting a to-and-fro and a rising-
and-falling movement to the alternate bars of the screen, the intermediate bars
being at rest. I form the entire screen into sections, each section consisting of a
fixed set of bars and of a moving set of bars, the fixed and moving bars alternating.
I prefer to make each of the two sets of bars in each section in one casting, of a
gridiron form, but the set of bars may be formed of separate castings, or bars
secured together, and the bars may be of cast iron, steel, or other suitable metal.
The higher end of each movable set of bars is mounted upon a crank shaft, to
which a revolving motion is imparted, so that the said end is moved to and fro and
also up and down. The lower end of the said set is arranged to slide to and fro or

page_text: is sustained by rockers or rocking struts or levers, or is mounted upon wheels, or is
otherwise so arranged as to be free to move to and fro.
The crank shafts actuating all the movable sets are by preference connected
together by means of a shaft and gearing, so as to revolve in unison. A compara-
tively thin plate covers the interval between one section and another and the spaces
unoccuppied by the fixed bars.
The coal to be screened is tipped on to the higher end of the screen as is usual,
and the movement of the parts of the screen, aided by the increased inclination of
the moving bars, when raised above the fixed bars, causes the coal to move down-
wards towards the bottom of the screen. Certain of the sections are formed with
bars wider apart than other sections, as in ordinary screens.
The method of actuating the moving bars may be varied, as for example,
they may be moved up and down and to and fro by means of rocking shafts.
My Invention may also be applicable to apparatus for screening gravel, potatoes,
corn, and other substances or matters, and in some such cases it may be advisable to
form the bars of the screen of brass, wood, or other suitable material.
A second part of my Invention relates to furnaces of steam generators, and to
other furnaces requiring to be regularly fed with fuel, and consists in the employ-
ment of fixed and movable sets of bars constructed and acting in a similar manner
to the sets of bars in my improved coal screen.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Landless in the Great Seal Patent Office on the 26th October
1877.
JAMES LANDLESS, of Nelson, in the County of Lancaster, Engineer.
" IMPROVE-
MENTS IN APPARATUS FOR SCREENING COAL AND OTHER MATTERS OR SUBSTANCES,
PARTLY APPLICABLE TO STEAM GENERATOR AND OTHER FURNACES."
My Invention relates in the first place to apparatus adapted more particularly to
be employed in the screening of coal.
In screens as ordinarily constructed, the coal is tipped upon the higher end of a
screen which is arranged at such an angle as that the coal will run quickly down
the screen, the slack and small coal passing between the bars of the screen. As the
coal rushes down the screen with an increasing velocity the coal becomes broken to
some extent in the screening operation, and the object of my Invention is to
remedy this defect. To this end I arrange the screen at such an angle, as that the
coal will not, by reason only of its gravity, run or rush down the screen from one
end to the other, and I assist the downward progress by imparting a to-and-fro and
rising-and-falling movement to the alternate bars of the screen, the intermediate
bars being at rest. I form the entire screen into sections, each section consisting of
a fixed set of bars and of a moving set of bars, the fixed and moving bars
alternating.
The higher end of each movable set of bars is moved to and fro and also up and
down. The lower end of the said set is arranged to slide to and fro, or is sustained
by rockers, or rocking struts or levers, or is mounted upon wheels, or is otherwise
so arranged as to be free to move to and fro.
The coal to be screened is tipped on to the higher end of the screen as is usual,
and the movement of the parts of the screen, aided by the increased inclination of
the moving bars, when raised above the fixed bars, causes the coal to move down.
wards towards the bottom of the screen. Certain of the sections are formed with
bars wider apart than other sections, as in ordinary screens.
.

page_text: My Invention may also be applicable to apparatus for screening gravel, potatoes,
corn, and other substances or matters, and in some such cases it may be advisable
to form the bars of the screen of brass, wood, or other suitable material.
A second part of my Invention relates to furnaces of steam generator, and to
other furnaces requiring to be regularly fed with fuel, and consists in the employ-
ment of fixed and movable sets of bars constructed and acting in a similar manner
to the sets of bars in my improved coal screen.
And in order that my Invention may be readily described and fully understood, I
have appended hereunto a Sheet of Drawings, made to a scale of about one and a
half inches to the foot, and marked with letters of reference, corresponding marks
indicating the same parts in the various Figures.
same;
Referring to the said Drawings, Fig. 1 represents a side elevation of a portion of
a coal screen constructed in accordance with my Invention; Fig. 2 is a plan of the
and Fig. 3 is a cross section on the line ** in Fig. 2. In the said Figs.
A, A, represent two of the said movable sets; and B, B, two of the said fixed sets.
Each movable set is composed of bars a, a, and each fixed set of bars b, b, which
alternate with the bars a, a. In the example the bars in each set are connected
together by means of end cross bars or beams, the whole of each set being formed
of cast iron in one casting; but this method of formation may be varied, as, for
example, the bars may be separately cast, and be bolted or united together, or be
cast in clusters of two or more bars, two or more clusters being united to form a
single set; or the said bars may be formed of wrought iron, steel, or other suitable
material instead of cast iron.
In Fig. 3 it will be seen that the ends of the bars b are united to a cross casting
B which is bolted to a beam C. The beam C is bolted between the girders D which
carry the sections of the screen. In the parts between the ends of the bars are
formed slots e to clear the bars a in the movable set. Each end of each of the sets
B is formed and sustained in a similar manner. The angle of inclination of the
screen which I consider to be suitable is indicated in Fig. 1. I prefer that the said
angle shall be such as that if a piece of coal be carefully placed upon one of the
fixed sets, when the movable sets are at rest, it will not slide down, but will have a
tendency to slide down with an extremely slight amount of assistance, that is to
say, I arrange that the said angle shall be about the greatest angle of repose for
coal lying upon a sloping metal grating. The lower end of each movable set is
supported by means of two rocking legs f, f. Upon each of the outer bars or sides
is cast or formed a trunnion, which works within a hole formed in the upper end of
the leg f. The lower end of the said leg is rounded, and rests in a hollow formed
in a chair g which is bolted to the girder D. The two legs of thus sustain the end
of the set of bars, and at the same time permit of a to-and-fro movement thereof,
the legs rocking in or upon the chairs g, g. This arrangement may be greatly
varied, as for example, the end of the section may be sustained by means of a
single rocking frame extending across the width of the screen, or the end of the
section may be arranged to slide to and fro, or to move on wheels or rollers, or be
fitted with wheels, as preferred. The higher end of each movable set is supported
by means of a crank shaft H, which is fitted to revolve in suitable bearings or
plummer blocks i which are bolted to the girders D. To or on the said set are
secured or formed seatings k, which are bored or hollowed, to rest upon the cranks
or the cranked portion or portions of the crank shaft.
It will be seen that when the crank shaft is caused to revolve, the higher end of
the set A is moved to and fro and up and down, rising above the upper surface of
the fixed set at one time and sinking below it at another time. To avoid using a
smaller scale, only one complete section of fixed and inovable sets and a. portion of
another section are represented in Fig. 2 of the Drawings; but it must be under-
stood that there are as many complete sections as may be considered to be necessary;
as for oxample, a coal screen which I have constructed has six sections, the distances

page_text: apart of the bars varying. The two upper sections are made with spaces between
the bars, suitable to permit the passage of the fine slack. The next section has
wider spaces, and the fourth set still wider, and so on as in ordinary screens.
The
coals passing through the spaces between the bars of each section is, or may be,
received into separate earts or chambers.
The crank shafts which actuate all the movable sets are connected together by
means of an inclined side shaft L, which is provided with bevil pinions m, which
gear with bevil wheels n, which are fixed on the ends of the crank shafts. In the
example the upper crank shaft is extended to receive a driving pulley o, which is
connected by means of a strap with a driving shaft or with a steam engine or prime
mover. The said crank shaft being thus caused to revolve in the direction indicated,
gives motion to the shaft L, which drives all the other crank shafts in the series,
whereby all the said crank shafts are caused to revolve in unison.
The arrangements for actuating the crank shafts may be varied, or, if preferred,
means other than the crank shafts may be used to impart the required movements
to the sets A, as, for example, they may be moved up and down and to and fro by
means of rocking shafts and levers. To the lower end of each movable set is
secured a thin plate p, to which is hinged a plate which rests by its outer end
upon the next set in the adjacent section. The use of this arrangement is to cover
the space between the ends of two contiguous sections, and to prevent the coal from
falling through or into the said space. The hinge permits the free end of the plate
to rise and fall with the movable set. A plate or guide s is also hinged to the
framework of the tipping platform t, and guides the coal on to the end of the upper
section. When the screen is in use the crank shafts are caused to revolve, and the
coal is tipped from the platform t on to the upper end of the screen, and is gradually
moved downwards by the movement of the sets of bars A.
It will be seen that when the crank shafts are caused to revolve in the direction
indicated the bars of the sets A, when raised above the bars b, are at the same time
moved downwards, the coal being thereby moved downwards; and that when the
bars a are moved upwards, they are withdrawn below the upper surfaces of the
bars b. As the coal is moved downwards it is screened, and the largest lumps are
delivered at the lower end of the screen, having sustained little or no damage
whilst running down the screen.
My Invention is also applicable to the screening of other substances than coal, as
herein-before mentioned; necessary modifications being made in the dimensions,
proportions, and material employed in the formation of the screen, the action of the
fixed and moving bars being retained. The crank shafts are provided with
weighted discs u to balance or partly balance the moving sets of bars.
When applying my Invention to furnaces, I employ a similar arrangement of
fixed and moving bars or sets, arranged either horizontally or at a suitable angle to
sustain the burning fuel, and to feed it gradually and progressively from one end of
the furnace to the other. When so applied, a grate for a single furnace may consist
of one complete section of fixed and moving bars, or of two or more sections, as
may be required.
Having now fully set forth and indicated the nature of my said Invention and
means whereby the same may be carried into effect, I would have it to be understood
that I claim,-
First. The combination and arrangement of parts, substantially as and for the
purposes set forth and indicated herein-before, and in and by the accompanying
Drawings.
Secondly. The employment in screens of moving bars alternating with fixed bars,
and having the movements substantially as set forth and indicated.
Thirdly. The employment in furnaces of moving bars alternating with fixed bars,
and having the movements substantially as set forth and indicated.
And, Lastly. The employment for the indicated purposes of fixed and moving
cast-metal gratings, arranged for the bars of the fixed grating to alternate with the

page_text: bars of the moving grating, the moving grating having the movements substantially
as set forth and indicated.
In witness whereof, I, the said James Landless, have hereunto set my hand
and seal, this Twenty-fourth day of October, in the year of our Lord
One thousand eight hundred and seventy-seven.
JAMES LANDLESS
fr.g)
Signed and sealed by the
Baid James Landless
in the presence of
HUGH GRANT,
Clerk to Edward K. Dutton,
3, Princess Street,
Manchester.