IMPROVE- MENTS IN MECHANICAL STOKERS FOR SUPPLYING FUEL TO THE FURNACES OF STEAM BOILERS AND IN APPARATUS CONNECTED THEREWITH."
Year: 1879

page_text: LETTERS PATENT to James Hodgkinson, of Bolton-le-Moors and Southport,
both in the County of Lancaster, Engineer, for the Invention of "IMPROVE-
MENTS IN MECHANICAL STOKERS FOR SUPPLYING FUEL TO THE FURNACES
OF STEAM BOILERS AND IN APPARATUS CONNECTED THEREWITH."
PROVISIONAL SPECIFICATION left by the said James Hodgkinson at the
Office of the Commissioners of Patents on the 25th July 1879.
JAMES HODGKINSON, of Bolton-le-Moors and Southport, both in the County of
Lancaster, Engineer. "IMPROVEMENTS IN MECHANICAL STOKERS FOR SUPPLYING
FUEL TO THE FURNACES OF STEAM BOILERS AND IN APPARATUS CONNECTED
THEREWITH."
In a mechanical stoker or feeding apparatus which is applicable to the furnace
of a locomotive boiler, the fuel to be consumed having been placed in a suitable
hopper or receptacle passes through regulators (which can be adjusted at will to
supply more or less fuel as required to be crushed for generating the steam) to the
revolving crushers which are situated directly underneath.
The crushers are made with teeth and cutters that will crush when driven either
way, which is necessary in stokers for locomotive furnaces on account of the back
and forward motions of the locomotive.
After the fuel has been crushed it falls on to a revolving beater or beaters,
which scatter the fuel which is fed to it over the fire and which is placed on the
furnace door, which when open the beater or beaters are of course displaced from
their true position for scattering the fuel on the fire, when a regulating slide is
closed, and thus stops the passage for the fuel from the crusher box to the beater
box, which continues until the door is closed again, after which the regulating
slide and door are not in positions just referred to; the fuel is fed towards the
regulating slide or door, and passes through the outlet in quantities depending
upon the area of the outlet as regulated by the said slide door to the distributing
apparatus. The said slide door also regulates the fuel according to the way the
locomotive is going, for when going in a forward direction it allows the fuel to fall
on the top side of the beater or beaters, and at the bottom side of the beater or
beaters when going in a backward direction. The shaft for driving the beater or
[Price 8d1

page_text: beaters passes through the same and the beater box, and is connected to a short.
piece of flexible coil of wire which allows the door to be opened; the other end is
attached to a claw coupling which is driven by pulleys actuated by ropes, belts,
chains, or other equivalents from the axles underneath, or other motive power.
The means I employ for disconnecting the claw coupling is a steel rod or flexible
tube or other equivalents passing through the beater shaft from the coupling to the
catch of the door, which when shut the coupling is in gear and the machine
working; when the door is open the beater or beaters are stopped.
The speed of the beater or beaters are regulated and varied by means of an
apparatus placed underneath the foot-plate, the fuel being thrown to the furthest
part of the fire when the maximum speed is obtained, and as the speed is gradually
reduced to a minimum the fuel is scattered from back to the front of the furnace
and vice-versá, thereby covering the whole fire surface mechanically.
In furnace bars for a locomotive I employ rocking and stationary bars which are
placed alternately, by which means the old method of pokering .the bars by hand
is dispensed with, the rocking or moveable bars being worked from the crusher
shaft or other points if necessary as circumstances permit.
In mechanical stokers for stationary boilers the fuel is placed in a hopper with
regulators above the revolving crushers, the crushers having teeth and cutters
which force the fuel forward in front of the teeth, thus ensuring a regular supply
to the carriers which supply the beater or beaters with fuel.
The beater or beaters are placed over the furnace door, above which is a regu-
lating plate worked mechanically so as to allow the fuel to drop on the beater or
beaters at, say, the right hand side of the flue and distribute its fuel along that
side of the fire only, leaving the other side to burn, by which means only one-half
the fire is fed at once with fuel; after a certain length of time the regulating plate
closes the right hand side and opens the left hand side, thereby alternate firing is
obtained, which has been proved to be the best means of preventing dense smoke
in hand firing.
The beaters are regulated in speed as before described, supplying the farthest
part of the fire when at the bighest speed, and the part near the furnace mouth
when at the slowest speed, the speed being regulated by cones or other equivalents
which are placed according to circumstances. I sometimes place the crusher box
and crushers at a point below the point of distribution, so as to allow of the hopper
being lowered considerably, which will be of great benefit to the firemen, besides
taking less room on the boiler front, and which in many cases will obviate the
removal of the various fittings.
In an arrangement of self-cleaning fire-bars these are alternately moveable and
stationary.
Some of the bars in a flue are what I term regulating fire-bars, the motion of
which is actuated by a cam or eccentric set in advance of the cams or eccentrics for
the other bars. All the moveable bars are carried and supported on rollers or
stays supported and carried by the regulating fire-bars, which when the moveable
bars begin to move outward alternately, the position of them is a little below the
stationary bars by which the clinker is left on them; when all the moveable bars
have been brought out, and while the cams or eccentrics are working round to
take them all back together, the cams or eccentrics of the regulating fire-bars being
in advance will have raised all the moveable bars above the stationary ones, so
that when all the moveable bars go back together they will carry the slag or
clinker towards the back end which will drop the same into a combustion chamber
provided for that purpose at the end of the furnace.
The moveable bars are worked by a shaft which is provided with cams or
eccentrics placed just outside the furnace front. In feeding I sometimes feed on
only a portion of the fire-bars, the remaining portion being covered by the motion
of the bars.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Hodgkinson in the Great Seal Patent Office on the 23rd
January 1880.
JAMES HODGKINSON, of Bolton-le-Moors and Southport, in the County of
Lancaster, Engineer. "IMPROVEMENTS IN MECHANICAL STOKERS FOR SUPPLYING
FUEL TO THE FURNACES OF STEAM BOILERS AND IN APPARATUS CONNECTED
THEREWITH."
My Invention has reference to new or improved arrangements or combinations
of the parts of automatic mechanical stokers and furnaces for steam boilers actuating
mechanism connected therewith, which will be more efficient and durable than
has been hitherto constructed, and has reference mainly to (1) means whereby pieces
of fuel exceeding the size desired to be thrown on the fire are broken up or reduced
and is fed to a discharge outlet, through which it passes onto a distributing
apparatus; (2), the use in conjunction with the reducing and feeding apparatus
of an appliance for regulating and when desired arresting the supply of fuel to the
distributing apparatus while the reducing and feeding apparatus continues in
operation; (3), an arrangement for driving the distributing apparatus in mechanical
stokers for locomotive furnaces in such manner as its motion shall be arrested when
and while the furnace door is opened; (4), an arrangement of crushers that will
operate on the fuel when driven either way as required in a mechanical stoker for
a locomotive furnace on account of the backward and forward motion of the same;
(5), the use of a distributing apparatus placed on the door of a locomotive furnace,
which when not in a true position for distributing fuel is arrested and stopped in
its operation; (6), in means for dispensing with the old system of pokering the
fire-bars of a locomotive furnace; (7), in means of apparatus for charging the
furnaces with fuel on each side alternately, which has been proved to be the best
means for the better prevention of smoke; (8), in apparatus for distributing the fuel
over any portion of the fire or all over; (9), in an arrangement of self-cleaning fire-
bars whose action is the same at both ends; (10), in an arrangement to prevent the
fire-bars of.the furnaces in boilers of steam vessels from locking themselves fast by
the motion of the vessel.
In order that my Invention may be fully understood and readily carried into
operation I will proceed to describe the accompanying Sheets of Drawings, reference
being made to the figures and letters marked thereon.
Fig. 1 represents my improved mechanical stoker and self-cleaning fire bars as
applied to the front of a stationary or marine steam boiler.
Fig. 2 is a sectional elevation of the same, and
Fig. 3 is an end view of the same.
The fuel is thrown into the hopper A, from whence it falls down into the crusher
boxes B, when the fuel is actuated upon and crushed to the requisite size desired,
which is regulated by screwing the hand wheel F' which acts upon the crusher
plate J, which will allow the fuel to be crushed to fine slack or nut slack.
After the fuel has passed the crushers it falls down the thoroughfare K¹ onto the
distributer E, from whence it is thrown onto the fire by the blades S.
The crusher plates J are made in such a form as shewn in the Drawings, so as
to allow of large pieces to drop below the centre of the crushers, and decreases in
curvature so as to allow the fuel to be crushed at twice, it being first broken up in
the upper part and to the desired size in the lower part. The crusher box is cast
for the crusher plate to drop in, so as to allow it to fit as near the front as possible,
thereby crushing larger pieces of fuel with a smaller crusher box than has hitherto
been the case.
. The distributors E are enclosed in boxes on the furnace fronts; the distributors
can be taken out and repaired if requisite without taking the furnace fronts off the

page_text: boilers or getting inside the flues to them as hitherto, which is performed by simply
drawing the shaft F out and taking a loose cover off the front of the box containing
the same, which is fastened only by set screws.
The distributors are fixed on and driven by the shaft F, which is driven by the
groove pulley A' from the differential motion overhead or any other convenient
position, so as to give a variable speed to the distributors, the object of which is to
throw the fuel to the fartherest part of the furnace when at a maximum speed, and
as the speed is gradually decreased the fuel is spread over the fire to the furnace
mouth at a minimum speed and vice versa.
The distributor blades are made similar to those in Fig. 5, which is shewn to be
opened out so that its surface lies on the plane of the paper.
Between the distributor and the crusher box is the regulating slide K², the
object of which is to effect side firing, or only allowing the fuel to drop on one
half of the distributor at once, thereby throwing the fuel to that side on which it
falls, which is worked as follows:-The crank or disc N, Figs. 1 and 4, is fixed on
the crusher shaft working in the lipped or paul wheel O, the object being to get a
slow motion during one part of the stroke; for instance, for four revolutions of the
crusher shaft the lever or rod P is sliding into position to raise the lever R during
the fifth revolution; of course the time can be varied to suit circumstances as may
be desired; at the same time the lever R is operated upon the lever T is also moved,
being on the same shaft or centre, and is connected by rods to the levers V, which
are fixed to the upright shaft U, which has two levers W fixed on, which are con-
nected to the regulating slides K2 by means of links fastened to them; thus the
lever R is operated on at intermittant points of the stroke, thus allowing the fire
to be supplied with fuel on each side alternately, for which purpose the bottom of
the crusher boxes are divided so that two regulating plates are acted upon at once,
one in each crusher box in the case in Fig. 1.
The crushers C are formed with teeth with sharp edges to split the fuel imme-
diately it comes in contact, and are fixed upon the shaft G, which is driven from
the worm F working into the worm wheel G³. The grooved pullies A² are driven
from above or any convenient position and have various sizes, so that the speed can
be altered at will; these pullies are fixed to a bush with the worm B¹ on it,
through which passes the shaft F, and which is supported at this end by the afore-
said bush, which is carried in the pedestals in the gearing bracket A³, the worm B¹
working into the worm wheel B2 driving the vertical shaft C', upon which is fixed the
worin F1 driving worm wheel G¹ on the crusher shaft and worm E' driving worm
wheel D¹ on the bar shaft K.
The door A is inclined inwardly to the edge of the dead plate, thereby ensuring
the fuel falling on the bars.
In my improved arrangement of self cleaning fire bars all the movable bars
(except the regulating bars) are driven forward together by a cam working in jaws
of the form shewn in Figs. 6 and 7, and can be brought back by the action of the
same cam that drives them forward, singly or in sets, or altogether depending upon
the shape of the aforesaid jaw.
My arrangement of these fire bars is alternately moveable and stationary,
H being the moveable ones; M, the stationary ones; 0%, the side stationary ones,
corrugated on the side to fit against the flues; M¹ are the regulating fire bars;
L, the eccentrics which actuate the regulating bars M¹; L¹, the front dead plate, to
which is cast or fastened the brackets C for carrying the front end of the stationary
bars; R¹ is the back dead plate which carries the back end of the stationary bars;
R2 is the door for the back end dead plate, which can be opened or closed by a
chain or rod from the furnace mouth for the purpose of cleaning the clinkers out
after it has fallen off the bars; a, a, are rods for tieing the dead plates together;
01 are levers for giving the requisite movement up and down; H' are bolts with
ferrules on which the moveable bars rest or sit.
The moveable bars H, in Fig. 6, are shewn in position for being worked back,
the surface of them being above the surface or level of the stationary bars M, the

page_text: fire being lifted off the stationary bars by the moveable ones when the cam K
works them all back together, thus carrying the fire the distance travelled; the
moveable bars rest on the rollers or shafts H, to which is connected the regulating
fire bars M', which are connected to the levers O¹, the position of which is per-
pendicular, or as may be desired, and at the highest point or otherwise when the
moveable bars are sent back by the cam K, the regulating fire bars M¹ are con-
nected and actuated by the eccentrics and rods L, which are set in advance of the
bar cam, the eccentrics being about full throw when the cam commences to operate
on the moveable bars H; therefore, when the moveable bars H are all worked back
the eccentrics or other equivalents have worked to such a position as to draw the
regulating bars M² and shaft H¹ back, which drops the moveable bars below the
stationary ones M, in Fig. 7, leaving the fire on the stationary bars M while the
bars H are drawn out separately, or in sets, or altogether after the moveable bars
are drawn out; the eccentrics or equivalents being in advance have worked round
and placed the regulating bars and levers in such a position as to raise them above
the stationary ones, and also the fire before being sent back to carry the same.
If the flues in a boiler or boilers are large enough I carry the front levers O³ from
the dead plate, as shewn, V¹, if not by a fixing marked T', in Fig. 10; the levers at
the back end are supported from brackets on the back dead plate.
Fig. 8 represents a plan of the bars.
Fig. 9 represents the back end of furnace shewing levers in position, as shewn in
Fig. 6.
Fig. 10 represents the front end with dead plate and bracket for small flues.
Fig. 11 represents the back end of stationary bars for the furnaces of boilers for
steam vessels which has a lip cast on T2 dropping into a receptacle in the back
dead plate, the receptacle being large enough for expansion; the object is to over-
come the tilting or jamming of the bars caused by the oscillation of the vessel; the
front end is held by the front dead plate, and so long as the stationary bars are
kept in position the moveable bars cannot get out of it; by this simple arrange-
ment this difficulty is obviated.
By the motion of these bars the fire is carried to the back end and dropped into
a combustion chamber provided for the purpose, which can be cleaned out by
opening the swing door in the back dead plate and raked out at night or other
times when the boiler is not at work, thereby there being no necessity for the
furnace door being opened during working hours.
The moveable and regulating bars are worked from the cam shaft K, placed out-
side the furnace front, as shewn in Figs. 1, 2, and 3.
In feeding I only need feed on part of the fire or the front part, the motion of
the bars carrying it on to the back end.
In my arrangement of mechanical stokers, which is applicable to the furnaces of
locomotive boilers, the fuel is thrown into the hopper A, in Fig. 12, from which it
falls into the crusher box B, the fuel being crushed by the crushers C, which are
formed so as to crush fuel when driven either way, according to the way the loco-
motive is travelling; this is owing to the machine being driven from the axles
underneath, as shewn; the crusher plates C¹ and C are placed front and back,
both being regulated from the front side by the hand wheels and screws D and U
or other equivalents from whence the fuel drops onto the distributor G¹ in the
box G on the furnace door, which is supported and driven by the shaft I, by which
action the fuel is thrown by the blades on the distributor to the fire beneath. The
crusher box is held and fastened to the front of the boiler directly over the
furnace door. The furnace door is fitted with the distributor box G and so formed
as to open on hinges or other equivalents; when this operation takes place the
slide is closed over the aperture C³ by the handle C2 to prevent the fuel dropping.
out of the crusher box.
The distributor is stopped immediately on raising the catch R, to which is
connected the levers T and flexible rod S or other equivalents, which disconnects
the coupling P, after which the door can be opened for any desired purpose. To,

page_text: allow the door to be opened, the driving shaft between the claw coupling P and
the distributor box is made preferably of flexible wire to give the swivelling or
bending action required; when the door is closed the claw coupling P is put in gear
by the dropping of the catch R in its true position.
It is obvious that various modifications may be made of the distributing apparatus
above described, and so long as its position in connexion with the door is main-
tained, which forms an essential feature in my Invention, the parts may be changed
and equivalent parts be substituted in various ways.
The shaft E for driving the crushers is driven from the beater shaft I or
equivalents by the worm J working in a worm wheel on the vertical shaft K, at
the top of which is fixed the worm M driving the wheel L which is fixed on the
crusher shaft E.
The distributor blades are made similar to those in Fig. 5, which is shewn to be
opened out so that its surface lies on the plane of the paper.
The distributor is driven by the groove pulley O from the groove pulley Vi
underneath the foot plates.
The distributor G₁ has a variable motion or speed, the object being as before
described in the mechanical stokers for stationary boilers.
I will now describe one of the modes of the differential motion which can be
applied, as shewn, underneath the foot plates, or in other positions, as may be
desired. The cone W is fixed on one of the wheel axles, from which is driven the
cone W' fixed on another shaft fixed in a convenient position by means of the strap
or belt A²; when the strap or belt is on the largest diameter of the cone it is
driving on the smallest part of the cone W¹, therefore giving the greatest speed
to the shaft which drives the groove pulley V, from which drives by a band V₁ or
other equivalents the groove pulley O on the distributor shaft I; when the strap is
at the smallest part of the cone W the cone W¹ is at the slowest speed, by which
action the distributor will have decreased from the highest to the slowest speed,
the object of which is described above.
The means I adopt (although other modes may be used) to cause the differential
motion is by placing the worm wheel Z on one of the axles working into the worm
wheel Y, to which is fixed a disc or eccentric plate which works the rod A', to
which is connected the strap fork and shaft, this giving the back and forward
motions of the strap which effects the variable speed of the distributors by the
intermittant connections.
In my arrangement of fire bars for a locomotive furnace I employ alternately
moveable and stationary bars. The moveable bars B', in Fig. 13, are carried and
supported by the levers B2, through which bolts pass on which the moveable bars
rest, the levers B2 being actuated by the eccentric or cam N on the crusher shaft
and the levers B3, B5, B6, and B7, and the connecting rod B*.
The action of the crusher shaft being slow the bars are moved up and down
slowly, thereby keeping them free from clinker, which is completely broken up,
thereby dispensing with the present system of pokering, which is a great annoyance
to the driver and stoker.
Having thus stated the nature of my Invention, and described the mode of
performing the same, I wish to remark that I do not intend to limit myself to the
exact details given, as in some cases the same may be varied according to the
peculiar purposes for which my improvements may be required, but that what I
claim and desire to be secured to me by the hereinbefore in part recited Letters
Patent is,-
First. The combination of parts forming my improved mechanical stokers, which
throw the fuel over the surface of the fire with a variable speed, of the distributing
apparatus and alternately side firing, constructed and operating substantially in
the manner described and as shewn on the Drawings.
Second. The construction and use, as applied either to stationary or locomotive
furnaces, of crushing apparatus, consisting of central crushers containing teeth or
blades and crusher plates which admit of the fuel being first broken up and then

page_text: crushed to the desired size, in the manner and for the purpose substantially as
described and shewn on the Drawings.
Third. The construction and use of feeding apparatus for effecting the supply of
fuel to the sides of the fire alternately, substantially as described and shewn on the
annexed Drawings.
Fourth. The construction and use of fire bars, so arranged and moved that they
are made to act as self cleaning surfaces, both ends of the bars being made to act
simultaneously together in such manner that all the moveable bars are carried
forward together and brought back separately, or in sets, or altogether, substantially
in the manner described and as shewn in the annexed Drawings.
Fifth. The use of stationary bars or their equivalents in connection with
mechanically moving bars, moved and working substantially as described and
shewn on the Drawings.
Sixth. Constructing or using mechanical stokers which throw fuel on the furnace
of a locomotive boiler, substantially as described and shewn on the Drawings.
Seventh. The use of distributing apparatus placed on the furnace door of a
locomotive boiler and provided with means of disconnecting the same when the
door is opened, substantially as described and shewn on the Drawings.
Eighth. The combination of moveable and stationary bars applied to a locomotive
furnace that will break the clinker, substantially as described and shewn on the
annexed Drawings.
Ninth. The use of regulating fire bars and levers actuated by eccentrics set in
advance of the bar cam, for raising and lowering the moveable bars above and
below the level of the stationary bars, for the purpose of carrying the fire towards
the back end of the furnace, applied and operated substantially as described and as
shewn on the annexed Drawings.
Tenth. The construction of mechanical stokers or apparatus for supplying fuel to
furnaces, applied and operated substantially in the manner described and as shewn
on the Drawings, and Figures 1 to 13.
In witness whereof, I, the said James Hodgkinson, have hereunto set my
hand and seal, this Twenty-first day of January, One thousand eight hundred
and eighty.
JAMES HODGKINSON. (L.S.)
Witness,
EDMUND CHADWICK,
Consulting Engineer and Patent Agent,
30, Arrowsmith Terrace,
Bolton-le-Moors.