IMPROVE- MENTS IN FURNACES FOR STEAM BOILERS AND APPARATUS CONNECTED THEREWITH
Year: 1874

page_text: LETTERS PATENT to James Marshall and James Lister, both of Gains-
borough, in the County of Lincoln, for the Invention of "IMPROVE-
MENTS IN FURNACES FOR STEAM BOILERS AND APPARATUS CONNECTED
THEREWITH."
Scaled the 25th June 1875, and dated the 30th December 1874.
PROVISIONAL SPECIFICATION left by the said James Marshall and
•
James Lister at the Office of the Commissioners of Patents, with
their Petition, on the 30th December 1874.
We, JAMES MARSHALL and JAMES LISTER, both of Gainsborough, in
the County of Lincoln, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN FURNACES FOR STEAM BOILERS AND APPARATUS
CONNECTED THEREWITH," to be as follows:-
Our Invention has for its object the providing of better facilities for
the utilization of straw and other light material as fuel for generating
steam in portable and other boilers, and consists mainly of an independent
fire-place or furnace to be used in connection and combination with tho

page_text: ordinary fire-box. Such fire-place or furnace may be either permanently
attached to or suspended from the ordinary fire-box or may be used inde-
pendent thereof, but in such a manner that the products of combustion
therefrom shall pass under the bottom of and into the fire-box.
"
The fire-place or furnace is constructed of fire-brick or other fire- |
resisting material enclosed in an iron casing, or may be a metal casing
lined with any fire-resisting material, substance, or guard having the fire-
bars or grate in the bottom thereof. The firc-door or feeding tube to the
furnace is in the front, the bottom or "dead plato being on a level with
the fire-bars, a portion of which extends into the feed tube. The dead 1
plate of the feed tube is arranged to form the door, and by a balance-
weight attached thereto is made self-closing as the fuel within the tubo
burns away.
In connection with the feed arrangement is a mechanical appliance for
raising the fuel from the fire-grate, consisting of one or more bont bars 1
worked by a lever, the effect of which is to lighten the fuel and inducc
quicker draught and combustion.
Between the bottom of the fire-box and the feed tube a metal guard
plate for protecting the front of the fire-box is placed, and so constructed
as to admit a current of air above the burning fuel to assist combustion 2
and prevent smoke.
The effect of our improvements is a more efficient application of light
matter for fuel, and to secure the more perfect combustion thereof.
The improved furnace as above described can be arranged with an
automatic feeding apparatus of the following description, in accordanco 2
with another part of our Invention:-This improved feeding apparatus
consists mainly of a revolving fork or forks fixed at the entrance of the
feed tube communicating with the furnace, and is driven by the engine.
In this arrangement a hopper is placed horizontally across the mouth of
the feed tube in such manner that the straw being laid at a right angle 3
to the fork and brought into communication with it is drawn into the
tube and forced forward into the furnace.
In connection with the revolving fork is a metal guard or guards so
arranged that their edge shall never be at an acute angle with the prong
of the fork, and this prevents the straw or fuel being drawn out of 3
the tube,

page_text: In further connection with the revolving fork and feed apparatus is an
arrangement for regulating the quantity of feed, consisting of a slotted
plate or guard so constructed as to allow the revolving fork to have
more or less action on the straw or fuel, as may be required.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Marshall and James Lister in the Great
Scal Patent Office on the 30th June 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, JAMES
MARSHALL and JAMES LISTER, both of Gainsborough, in the County of
Lincoln, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of Decomber, in tho
year of our Lord One thousand cight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said James Marshall and James
Lister, Her special license that we, the said James Marshall and James
Lister, our executors, administrators, and assigns, or such others as wc,
the said James Marshall and James Lister, our executors, administrators,
and assigns, should at any time agree with and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within tho
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN FURNACES FOR STEAM
BOILERS AND APPARATUS CONNECTED THEREWITH," upon the condition (amongst
others) that we, the said James Marshall and James Lister, our exc-
cutors or administrators, by an instrument in writing under our or
their hands and scals, or under the hand and scal of one of us or them,
should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE that I the said Tamos Manchell

page_text: said Invention, and in what manner the same is to be performed, to bo
particularly described and ascertained in and by the following statement
thereof, that is to say :—
•
The object of this Invention is to provide suitable means and apparatus
for the consumption of straw or other light vegetable matters as fuel for 5
the boilers of portable and other engines without interfering with their
utility for being fed with wood or coal when desired.
The apparatus shown in Figures 1, 2, and 3 of tho Drawings hereunto
annexed forms an addition to the ordinary fire-box of a portable engine
consisting of an independent fire-place or furnace A lined with fire-brick 1
or other fire-resisting material, substance, or guard, having the fire-bars
or grate (B) in the bottom thereof. The firc-door or feeding tube (C)
to the furnace is in the front, the bottom or dead plate (D) being on a
level with the fire-bars, a portion of which extends into the feed tubc.
The dead plate D of the feed tubo is arranged in two parts, the portion 1
marked D¹ being of wrought iron connected to a swivel bar E, to which
is attached a lever and balance weight F. By this means as the straw
burns away the lever and weight F fall, thus raising the dead plate D'
and closing the entrance to the furnace.
In combination with the above apparatus a mechanical appliance is 2
arranged for occasionally raising the fuel and breaking up the clinker
which may form on the bars, thus maintaining a clear grate for the free
admission of air. This appliance consists of a number of bent bars G, G,
secured on a spindle H, to which is attached a hand lever I to actuate or
move the bent bars G, G, up and down between the fire-bars when 2
required.
Between the bottom of the fire-box and the feed tube a metal guard
plate or shield K is introduced for the double purpose of protocting the
bottom of fire-box and at the same time admitting a film of air over the
burning straw to assist combustion and prevent smoke.
The ash-pit is enclosed by hinged plates M, M, attached to the furnace
casing. These plates M, M, can be turned up when the engine is required
to be moved.
For facilitating feeding the straw or other vegetable matter into tho
furnace we sometimes arrange the said furnace with a mechanical
appliance attached to the upper part of the mouth-piece, as represented

page_text: in Figures 4, 5, and 6 of the Drawings annexed, consisting of a revolving
fork O, the prongs of which are secured to a spindle P, to which motion
is communicated by a pulley Q driven from engine crank shaft. A
feeding plate R is attached to the front of the feed tube C to receive the
straw or other material to be fed into the furnace. To regulate the feced
a second series of prongs S are provided secured on a bar T, which by
means of the hand lever U either raises or depresses the prongs S, thus
giving the revolving forks more or less feed as may be required.
In connection with the revolving fork guard plates are introduced so
arranged that their faces shall never be at an acute angle with the prong
of the fork, thus preventing choking. The straw being laid at right
angles to the fork is drawn into the tube and forced forward into the
furnace.
Having thus described the nature of our Invention and the manner of
performing or carrying the same into practice, what we claim is,--
The improved arrangement of the furnaces of steam boilers and
apparatus combined therewith to facilitate the burning of straw or other
fuel, substantially as and for the purpose herein-before described and
represented in Figures 1, 2, and 3, of the Drawings hereunto annexed.
We also claim the improved arrangement of the furnaces of steam
boilers and apparatus combined therewith to facilitate the burning of
straw or other fuel, substantially as and for the purpose herein-before
described and represented in Figures 4, 5, and 6 of the Drawings here-
unto annexed.
In witness whereof, I, the said James Marshall, have hereunto
set my hand and scal, this Twenty-fifth day of June, in the
year of our Lord One thousand eight hundred and seventy-
five.
JAMES MARSHALL. (L.S.)