Improvements in and relating to Mechanical Stokers.
Year: 1897

page_text: Date of Application, 6th Oct., 1897
Complete Specification Left, 4th July, 1898-Accepted, 3rd Sept., 1898
.
PROVISIONAL SPECIFICATION.
Improvements in and relating to Mechanical Stokers.
I, WILLIAM WHITTAKER, of Yorkshire Street Ironworks, Burnley, in the County
of Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
Its objects are:-
1st. To obtain a more variable and wider range of regulation in mechanical
stokers, so as to render them applicable to any description and size of boiler, and
permit of their being readily, expeditiously and effectually adjusted to meet the
requirements or consumption of such boiler, whether of a small, medium, or
large size, or type.
2nd. To render such stokers more effectual and economical in action.
3rd. To obviate the accumulation of dust or small particles of coal on the
dead-plate, and thus minimise the formation of smoke;"
4th. To preserve or prolong the life of the dead-plate, and
5th. To save labour and fuel.
In order to successfully accomplish these desirable objects, I construct and fix
the machine in a somewhat similar manner to that described in the Specification
of my Letters Patent No. 560 of 1887, substituting for some of the parts and
methods, the following improvements, viz. :-
To more effectually regulate the quantity of coal to be fed to the feed-rollers in
the roller-box at the bottom of the hopper, I employ a shaped regulator, hav-
ing a slide-plate on each side, working in grooves, by which it is retained in its
proper position.
To these slide-plates, I attach a lever, by means of a stud, on which it can move
freely.
This lever is supported by a stud, acting as a fulcrum, mounted on the outside
of the hopper.
A small bracket is securely fixed to the hopper and has a slot, through which
a threaded stud, or the like passes, and permits of the lever being held firmly
thereto by means of a wing-nut, thumb-screw, or equivalent, so that by depres-
sing or raising the handle provided on the outer end of the lever, the slides at their
other extremity will be regulated, and the aperture at the bottom of the hopper,
and the feed of coal increased or decreased accordingly.
In order to minimise the accumulation of small coal on the dead-plate, or its
equivalent the bars hereinafter mentioned I employ a clearing-plate, which
works on hinges fixed to, or in a groove or grooves in the dead-plate, or in a bar
inserted therein, in such a manner as to be raised and lowered when the furnace
door is closed and opened, respectively.
When the door is open, the clearing-plate lays flat on the dead-plate, and is flush
therewith and does not project above so as to interfere with the operation of the
boiler-man, when cleaning or attending to his fire.
The inside of the door is provided, with a curved or horn-shaped bracket, pro-

page_text: jecting therefrom, and in such a way that when the door is being closed the tip
or point of the horn passes under a roller mounted on, and parallel with the
outer edge of the clearing-plate, and in doing so, raises the plate to an angle of
about 45-60° with the dead-plate, in which inclined position it remains, while the
door is closed, (the top edge of the plate being near to the under edge of the
mouth of the shovel-box) consequently the small particles of fuel (which are not
thrown on to the fire or grate-bars, by the revolving shovels, but drop on to the
clearing-plate) gravitate down it, on to the dead-plate.
This clearing-plate may also be actuated automatically, to do which, I attach
either one or more rods to the catch-rods (described in the specification aforesaid)
bring them down the front of the stoker, and attach them to another rod.
To the latter, I attach one or more catches, which engage with a wheel, actuated
by a pinion.
Under the clearing-plate and above the dead-plate I fix a semi-circular plate
or half-moon on a stud or shaft, attached to the boiler front or dead-plate; on
this stud or shaft, and in front of the half-moon, is placed a catch-wheel which
is actuated by the catch-rod moving to and fro, causing the catch to take one
or more teeth: another catch on the same rod also engages with the wheel on
the opposite side, one catch moving and the other holding it in position.
By actuating the wheel by these catches as described, and the wheel being on
the same pinion as the half-moon, it gives the latter a circular motion, the semi-
circular plate moving under, and being in contact with the clearing-plate, causes
it to be elevated and deflected, e.g. when the half-moon is inverted, the clearing-
plate lays flat on the dead-plate, and is elevated to the highest position it can
attain when the half-moon is reversed.
A slot is provided in the dead-plate to allow the half-moon to penetrate when
lifting the clearing-plate.
The catch-rod is moved by gearing and a lever, giving a reciprocating motion:
the catch being actuated by the lever, causing the wheel to be taken up one
or more teeth as desired, and thereby elevates or deflects the clearing-plate.
Instead of the automatic arrangement just described for actuating the clearing-
plate, it can be worked by hand, for which purpose I arrange the half-moon on
a stud or shaft fixed under the dead-plate or in any other suitable position, and
work it by means of a rack or wheel engaging on the half-moon..
By this method, the clearing-plate can be raised or lowered at will by the boiler-
man.
The roller on the back or outer edge of the clearing-plate, can be utilized by
the boiler-man when using his fire-irons, and by doing so, he will not only
expedite and minimise his work, but find it considerably less laborious than he
does without the assistance of this roller.
At the foot of the clearing-plate, and between that point and the fire-bars, I
form a grate in the dead-plate by inserting therein, one or more bars in such a
way as to form air-passages, to allow a current of air to pass through from below,
so as to ensure the ignition and combustion of the small coal deposited thereon,
without destroying the dead-plate: one of the objects of these bars being to
obviate the necessity of having to renew the dead-plate when damaged by fire.
Instead of using bars to form a grate in the dead-plate, the latter may be per-
forated and have bushes inserted in the holes so that when the bushes are burnt
and require replacing, they can be readily taken out and new ones substituted.
The dead-plate is suitably formed to receive these bars or perforations and
bushes, and the support for the clearing-plate, and is also provided with an aper-
ture behind the latter, to permit of a current of air to pass upwards at the back
thereof, and enter the furnace through suitable openings therein.
Deted this 5th day of October 1807

page_text: Improvements in and relating to Mechanical Stokers,
I, WILLIAM WHITTAKER, of Yorkshire Street Ironworks, Burnley, in the County
of Lancaster, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:
This invention has reference to certain improvements in and relating to
mechanical stokers, and is designed firstly to get rid of the accummulation of
dust or small particles of coal on the dead plate in front of the grate bars, and
thus diminish to a considerable extent the formation of smoke; secondly to fur-
nish air inlets to the furnace to cool the dead plate and prolong its life, and at
the same time assist combustion, and thirdly, to so arrange the feed of the stoker
that it can be readily adjusted to meet the requirements or consumption of the
boiler, whether the same be of a small, medium or large type.
a
With regard to the first part of this invention, which is designed to minimise
the accummulation of small coal on the dead plate, I fit into the dead plate
movable plate, which I will term the clearing plate. This clearing plate works
on pivots, which fit into grooves or sockets in the dead plate, and so arranged as
to be raised or lowered by the opening or closing of the furnace door, and in such
a manner as to cause the particles of coal accummulated thereon to gravitate on
to the fire-bars.
On the inside of the furnace door, I fix a curved or horn shaped bracket, which
projects therefrom in such a way, that when the door is being closed, the tip of
the horn comes against the bevelled edge of the clearing plate, and raises it to
an angle of about 45 to 60 degrees with the dead plate. The clearing plate remains
in this inclined position when the door is closed. the top edge of the clear-
ing plate being near to but just clear of the under-edge of the mouth of the
shovel box, consequently small particles of fuel, which are not thrown on the
fire-bars, gravitate down the clearing plate on to the same.
I fit in the dead plate underneath the clearing plate, one or more pivotted
ashes bars, provided with a projecting nib, by which they have a rocking move-
ment imparted to them on the fall of the clearing plate, a small stud or projection
thereon coming against the said nib, and thereby cause the said bar or bars to
rock or swivel. This arrangement is of advantage when cleaning the fire-bars, as
it enables me to get rid of the ashes, which may find their way underneath the
clearing plate on to the dead plate.
I also make provision for a constant circulation of air around the clearing plate
to cool the same. For this purpose I provide an air inlet between the ashes
bar and the dead plate, and also a small aperture behind the clearing plate and
its top edge, so as to permit a free circulation of air to pass upward through the
dead plate and around the clearing plate.
When the door is opened, the clearing plate does not interfere with the opera-
tions of the boiler man, but lies flush with the dead plate.
The second part of my invention consists in the provision of an air inlet or
air inlets to the dead plate at the foot of the clearing plate or in close proximity
thereto. These air inlets preferably take the form of a grate in the dead plate
by inserting in an open space formed therein one or more bars in such a manner,
as to form air passages. A continuous current of air is thus set up, which not
only tends to cool the dead plate, but also assists in the combustion of fuel
deposited on it.
The dead plate may be perforated or otherwise formed with air spaces instead

page_text: of the said fire-bars, but I prefer the latter method. In such case, the perforations
are bushed, so that the bushes may be replaced when burnt.
The third part of my improvements is designed to more effectually regulate the
quantity of coal to be fed to the feed rolls in the roller box at the bottom of the
hopper. I employ a A shaped regulator having a slide plate on each side, which
works in grooves in the feed regulator. These slide plates are actuated by a lever,
and the object of this part of my invention is chiefly to adjust the position of
this lever, so that the delivery of coals to the feed rolls may be regulated more
minutely.
The lever is supported by a stud acting as a fulcrum mounted on the side of
the feed regulator. A small bracket securely fixed to the hopper is furnished
with a slot. A threaded stud is passed through a hole in the lever, and also
through this slot, and a winged nut is tightened on the threaded extremity of
the stud, so that the lever may be firmly held in position after the handle formed
at its extremity has been raised or lowered to the required degree.
In order that my invention may be fully understood, I have hereunto annexed
drawings, in which
Figs. 1 and 2 are detached sectional side elevations of a boiler furnace with my
improvements applied in accordance with the first and second parts of my inven-
tion, and Fig. 3 is an elevation of the hopper box of a mechanical stoker, fur-
nished with means for adjusting the hand lever for regulating the delivery of the
coal supply in accordance with the third part of my invention.
Referring to Fig. 1, A is a furnace door, 13 the horned shaped bracket bolted
thereto. C is the clearing plate pivotted at D to the dead plate E. When the
door is open, this clearing plate lies flush with the dead plate as shewn in Fig. 1.
When the furnace door A is closed, as shewn in Fig. 2, the point or tip of the
horn bracket B is passed under the bevelled edge of the clearing plate C, and
raises it to the position shown in Fig. 2, thus causing the accumulated particles of
coal to gravitate to the firebars, and be consumed by the fire.
In these views is also shewn my improved arrangement for freeing the dead
plate underneath the clearing plate of any ashes, which may find their way
thereunder during the operation of cleaning the firebars. In the dead plate E,
underneath the clearing plate C, is fitted a rocking ashes bar G having projecting
nib H. As will be seen in Fig. 1, the stud F on the clearing plate raises the
rocking bar G by depressing the projecting nib H on the fall of the clearing
plate C, thereby allowing ashes and small particles of coal to fall in the flue of the
boiler beneath. When the clearing plate C is raised with the closing of the fur-
nace door, the ashes bar G assumes its normal position.
An air inlet is made at U situated preferably between the ashes bar G and nib H,
and the dead plate E. A small air passage V is allowed between the top of the
clearing plate, and the under edge of the shovel box when the clearing plate is in
a raised position, as seen in Fig. 2. By this means a free circulation of air is
allowed to pass around the clearing plate, as indicated by arrows, which keeps
the said plate cool, and unaffected by the heat of the furnace.
I would here observe that the clearing plate C may be operated by other
mechanical means than the opening or closing of the furnace door, as for instance
it may be operated from any desired moving part of the stoker, or it may be
operated by hand without departing from the spirit of my invention.
In the dead plate I form a space for the réception of a grate consisting of one
or more bars J to form air inlets K in the dead plate to cool the latter, and at the
same time assists in the combustion of the fuel resting thereon.
These air passages may be formed by perforating the dead plate or other means.
My improved means of regulating the delivery of coal to the feed of mechanical
stokers is shewn in Fig. 3. The A shaped regulator L of the hopper is formed
with grooved side pieces M for the reception of the slide pieces N. These slide
pieces are actuated by the hand lever 0 working upon the stud P as upon a
fulcrum.

page_text: On the hopper is fixed the bracket Q having a slot R formed in it. Through
this slot is passed the threaded stud S, which enters a hole in the lever O, and when
the desired position of the lever has been obtained, a winged nut at the threaded
extremity of the stud S is tightened to firmly secure the lever. By this arrange-
ment the delivery of the coal to the feed rolls can be regulated to a nicety.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. The arrangement and construction of clearing plate C arranged to move
radially upon its pivots D, and operated by the opening or closing of the furnace
door, or by some mechanical equivalent, or by hand, substantially as and
for the purpose described and illustrated in Figs. 1 and 2.
2. The improved arrangement and combination of rocking ashes bar G with the
clearing plate C, substantially as described and illustrated in Figs. 1 and 2 for
the purpose set forth.
3. In combination with clearing plate C, air inlets U and V to permit a circu-
lation of air around such clearing plate substantially as described and illustrated
in Figs. 1 and 2.
4. Furnishing the dead plate with perforations bushed or otherwise, or with
bars J J provided with an air inlet or air inlets K between them to ensure the
ignition of small coal deposited thereon and cool the dead plate, substantially as
described and illustrated.
5. The horn or curved bracket B fixed to the furnace door A for operating the
clearing plate, substantially as described and shewn.
6. The improved means of regulating the delivery of coal to the feed of
mechanical stokers consisting of bracket Q having
a slot formed in it, through
which threaded stud S is passed, and having a winged nut at its threaded extremity
to retain firmly in any desired position the hand lever 0, substantially as described
and shewn in Fig. 3 of the accompanying drawings.
1000
RICHMOND & Co.,
Chartered Patent Agents, 12, Standish Street, Burnley.