Improvements in or applicable to Mechanical Stokers.
Year: 1891

page_text: Date of Application, 28th Dec., 1891
Complete Specification Left, 9th June, 1892-Accepted, 9th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in or applicable to Mechanical Stokers.
I WILLIAM DENHAM GRIMSHAW of Plantation Mills Accrington in the
County of Lancaster, Calico Printer, do hereby declare the nature of this invention
to be as follows:-
This invention relates mainly to apparatus known as Leach's mechanical stoker
wherein a feed box or boxes reciprocating beneath a coal hopper supplies fuel to
two fans which project it over the furnace.
In the first place I use three fan boxes and fans for supplying the fuel, and
above the mouth of the central fan box I fix an adjustable plate to direct the
central spray down on the fire; at the mouth of each of the side boxes and at the
inner side thereof mount, on a vertical hinge, a plate so fitted with a screw or
other means of adjustment that it can be set at a suitable angle to direct the fuel
to the sides of the furnace. This arrangement will heap up the fuel at the sides
more than in the centre of the furnaco and this is the most advantageous manner of
stoking, as the greatest heat is generated at the furnace sides where it is most
required.
I also combine with this arrangement an air and steam injecting pipe similar to
that for which I obtained Letters Patent No. 7625 of 1890 to promote and increase
the thorough combustion of the fuel and prevent smoke.
By these means I dispense with the oscillating deflecting plates used in the above
named stokers, I also propose to dispense with the sliding feed box and in place
thereof to make use of a plain rake provided with a projection in the shape of a
cross which extends up into the open bottom of the hopper and as the rake moves
prevents the coal from agglomerating in the said opening and stopping its descent
from the hopper.
Instead of fixing a crank pin in a slot in the worm wheel which actuates the
slotted rod to obtain the reciprocating motion of the rake I use a circular excentric
plate working in the said slot and provided with a slot through which passes a flat
block provided with a screw at its inner end to fix it to the worm wheel shaft.
This block is provided with a square or other suitably shaped head to keep the
circular excentric plate in place and the latter is provided with lugs through which
passes an adjusting screw which also passes through the head of the block which
1S tapped" with a screw thread and so, by turning the screw. in one direction or
the other, the throw of the rake can be adjusted and as the slotted rod may be
provided with an indicating scale and the eccentric with a diametric line or murks
this adjustment can be most accurately effected, according to the amount of fuel
which it is desired to supply to the fans at each stroke.
I prefer so to increase the speed of the worm wheel which actuates the supply
of fuel to the fans and to reduce the stroke of the reciprocating feed box or rake
that a light but almost continuous supply of feed is maintained.
Dated this 24th day of December 1891.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in or applicable to Mechanical Stokers.
I WILLIAM DENILAM GRIMSHAW of Plantation Mills Accrington in the
County of Lancaster Calico Printer, 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 that class of mechanical stokers in which fans are
employed to project the fuel into the furnace, and the same will be readily
understood from the following description and on reference to the accompanying
sheet of drawings.
Fig. 1 is a front view partly in section of a double flued furnace provided with
a mechanical stoker constructed according to my invention;
Fig. 2 is a vertical section through about the centre of one of the flues.
Fig. 3 is a horizontal section of the same.
Fig. 4 is a view taken from the inside of one flue.
Figs. 5 and 6 are detached views drawn to a larger scale of the means for
adjusting the excentric and the slotted feed rod hereafter more particularly
described.
In the first place I use three fan boxes a a' a' and fans b 6' 62 for supplying the
fuel and above the mouth of the central fan box a' I fix an adjustable plate ch to
direct the central spray down on the fire.
At the mouth of each of the side boxes a and a² and at the inner side thereof I
mount on a vertical hinge a plate marked c and c³ respectively on Fig. 3 of the
drawings, and I provide these plates c¹ and c³ with screws d d and or other
equivalent means of adjustment so that each plate can be set at a suitable angle,
c and being set to direct the fuel to the sides of the furnace.
as
By this arrangement the fuel will be heaped up more at the sides than in the
centre of the furnace, and this is the most advantageous manner of stoking
the greatest heat is generated at the furnace sides, where it is most required.
.
I also combine with this arrangement a perforated pipe e similar to those
described in the Specification of Letters Patent No. 7625 granted to myself and
dated May 16th 1890 for supplying air, steam, or air and steam to the furnace and
I so regulate the supply of fuel as hereafter described that a light but almost
continuous supply of fuel is maintained and by these means thorough combustion
of the fuel is secured and the escape of smoke is prevented.
The fuel is supplied to the fan boxes a a¹ a² by a reciprocating rake gland feed
rod provided with an open slot as usual in this class of stoker but I provide
the following means for adjusting the stroke of the rake as seen at Figs. 1-5
and 6.
In the slot h¹ of the feed rod works a circular excentric plate i made with-a
slot through which passes a flat block screwed into the shaft of the usual
worm-wheel m used for imparting motion to the said 'feed rod the block kis
made or provided with a square or other head k¹ and the plate is provided with
lugs and
Au adjusting screw * passes through these lugs and and through the head k¹
of the block k and the latter is tapped with a screw thread so that by turning this
screw in one direction or the other the eccentricity of the plate i and consequently
the throw of the rake can be adjusted.
By adjusting the plate i to make a short throw and by driving the worm wheel m
rapidly am enabled to maintain a light and practically continuous supply of fuel
to the fan boxes a a¹ a² for the purpose herein before mentioned.
I also connect the slotted part h' to the rods h so that the throw of each of the
rods h can be separately adjusted in case one fire requires more fuel than the other
or if it is desired to put one fire out while the other is kept alight, and this I effect

page_text: Between
by providing each side of the part with a short arm or socket carrying a right
and left handed adjusting screw h³ on which are mounted two nuts o o¹.
these two nuts o and o¹ a projection h³ from the rod is held and thus if the two
nuts o and o' both touch the said projection ³ the rod h and the rake g will receive
the full motion or stroke of eccentric plate i but the further apart the two nuts are
set by the screw the shorter will be the stroke or traverse of the rod h and
rake and thus each of the rukes may be adjusted to work as required (or to cease
work altogether) independently of the action of the other rake.
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
1. The means substantially as hereinbefore described for supplying fuel to a
furnace, consisting of three fans, with three openings into the furnace the central
opening being provided with a downwardly directing plate and the side openings
with plates, directing the fuel to the sides of the furnaces.
2. The combination with such fans and directing plates of a perforated pipe for
the injection of hot air and steam into the furnace which is supplied by the means
above described with a continuous light spray of fuel.
3. The means for communicating motion from the worin wheel to the feed rake
substantially as hereinbefore described and illustrated by the annexed drawings.
Dated this 8th day of June 1892.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.