IMPROVEMENTS IN GRATES FOR COAL DUST PROVIDED WITH A SHAKING APPARATUS
Year: 1871

page_text: LETTERS PATENT to Theodor von Bolzano, of Schlan, in the Empire
of Austria, Manufacturer, for the Invention of "IMPROVEMENTS IN
GRATES FOR COAL DUST PROVIDED WITH A SHAKING APPARATUS."
Sealed the 10th November 1871, and dated the 19th May 1871.
PROVISIONAL SPECIFICATION left by the said Theodor von Bolzano
at the Office of the Commissioners of Patents, with his Petition, on
the 19th May 1871.
I, THEODOR VON BOLZANO, of Schlan, in the Empire of Austria,
Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN GRATES FOR COAL DUST PROVIDED WITH A SHAKING APPARATUS,"
to be as follows:-
:-
This Invention has reference to an improved construction of furnace
grates for burning coal dust or small coal.
For this purpose two sets of bars are arranged one in advance of and
somewhat below the other in the manner of steps, the bars of each set
being slightly inclined downwards from the outer towards the inner end
of the grate, and the lower ends of the bars in each set are formed with

page_text: notches on their upper surfaces, constituting a series of small steps.
Every alternate bar in each set is secured to a framing, the side plates of
which are also stepped to correspond with the upper surface of the two
sets of bars. The intermediate bars between the fixed ones of each set
are moveable, being supported at their upper ends by transverse supports
fixed to the before-mentioned framing, while at the lower ends they are
provided with projecting lugs on their under sides into notches, in which
fit short levers fixed to transverse shafts carried by the before-mentioned
framing. To these shafts a rocking or vibrating motion can be imparted
by means of levers passing underneath the grate bars to the outside of
the furnace, where they are provided with handles so as to be moved by
hand. By such rocking or vibrating motion of the shafts a slight up-and-
down motion may be imparted at intervals to the intermediate bars of
each set, thus breaking up and shaking the caked incandescent coal upon
the bars and causing the same to move gradually forward from the outer
end to the inner end of the furnace grate. An inclined plate is fixed
below the upper set of bars on a level with the lower set, leaving a space
between the plate and the bars for the passage of air and also for the
introduction of a stirring tool through the space between the upper and
lower sets of bars. Somewhat below the inner end of the lower set of
bars is fixed a horizontal transverse plate and a framing carrying one or
more loose gratings upon which the ashes and cinders from the inclined
grate bars descend, and which can be slid out beneath such grate bars by
means of handles in order to remove the accumulation of ashes and
cinders. At the outer end of the furnace grate above the upper set of
grate bars is fixed an upright transverse plate with sight holes for
observing the state of combustion in the furnace, and a slit is provided
between the bottom of this plate and a horizontal plate covering the
upper ends of the grate bars for the introduction of a stirring tool.
Above the upright plate is placed a hopper or feed box turning on
centres, which feed box is first placed in a horizontal position to receive a
charge of coal dust or small coal, and it is then tilted up so as to cause
the charge of coal to fall on to the upper set of grate bars. When in the
horizontal position this feed box entirely closes the space at the front
end of the furnace above the grate bars so as to prevent the introduction
of air at that point,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Theodor von Bolzano in the Great Seal Patent
Office on the 16th November 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THEODOR
VON BOLZANO, of Schlan, in the Empire of Austria, Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of May, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Theodor von Bolzano, Her special
licence that I, the said Theodor von Bolzano, my executors, admi-
nistrators, and assigns, or such others as I, the said Theodor von
Bolzano, my 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 the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN GRATES FOR COAL DUST PROVIDED WITH A SHAKING APPARATUS,"
upon the condition (amongst others) that I, the said Theodor von Bolzano,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, 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 Theodor von Bolzano, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the accom-
panying Sheet of Drawings and to the figures and letters marked
thereon, that is to say :-
This Invention has reference to an improved construction of furnace
grates for burning coal dust or small coal, the arrangement of the
several parts of which will be clearly understood on reference to the
accompanying Sheet of Drawings, on which Figure 1 shews a longi-
tudinal section of the furnace grate and apparatus in connection there-

page_text: with; Figure shews a plan thereof with the lower set of grate bars
removed; and Figure 3 shews a front view of the framing. Similar
letters of reference indicate similar parts in each of the Figures.
The furnace grate consists of two sets of bars a, a¹, the one set a¹
being in advance of and somewhat below the other set a, the bars of
each set being slightly inclined downwards from the outer towards the
inner end of the grate as shewn, and the lower ends of the bars are
formed with notches on their upper surfaces constituting a series of
small steps. Every alternate bar in each set is secured by clamps t to
the transverse supports d¹ of the side framing d, d, which is also stepped
to correspond with the upper surface of the two sets of bars. The inter-
mediate bars between the fixed ones of each set are moveable, being
supported at their upper ends by the transverse supports & to the
side framing, while at their lower ends they are provided with lugs a'
into notches in which fit short levers 6¹ fixed to transverse shafts b
carried by the side framing. To these shafts a rocking motion or partial
rotary motion can be imparted by means of levers 62 fixed thereto and
passing underneath the grate bars to the outside of the furnace where
they are provided with handles as shewn so as to be moved by hand.
By such rocking motion of the shafts a slight up-and-down or "jogging".
motion may be imparted at intervals to the intermediate bars of each
set by means of the short levers 6¹ so as to break up and shake the caked
incandescent coal upon the bars and thus cause the same to move
gradually forward from the outer end to the inner end of the furnace.
An inclined transverse plate o is fixed below the upper set of bars on a
level with the lower set, leaving a space & between the plate and the
upper bars for the introduction of a stoking bar into the fuel on the
lower bars. The plate o not only facilitates such introduction of the
stoking bar, but also serves to catch any portions of unconsumed fuel
that may fall through the upper set of bars, which portions of fuel are
then pushed through the opening 8¹ on to the lower set of grate bars
in order to be burnt up there. Below the lower set of bars is a trans-
verse plate d³ fixed to the side framing, and below this plate is a framing
c carrying one or more loose grates c² (three such are shewn on the
Drawing) upon which the ashes and cinders from the inclined grate bars
descend, and which can be slid out beneath the grate bars by means of
handles fin order to remove the accumulated ashes and cinders.
step-like ends of the grate bars and the plate & serve to catch the
descending pieces of coal so that they may be thoroughly burnt up;
The

page_text: they also serve to prevent the unburnt coal from falling down when the
grate plates c¹ are drawn out as described. The inclination of the grate
bars a, a¹, which has been found most advantageous in practice, is about
fifteen degrees. The furnace is closed in front against the entrance of
cold air above the fire, firstly, by means of a fixed transverse plate n
having sight holes n¹ for observing the state of the fire, and, secondly,
by the feed box or hopper h, supported on trunnions m resting in
bearings on the side framing of the furnace, which hopper consists of
a flat plate with two vertical sides and is capable of being turned from
the horizontal position shewn on the Drawing into a vertical position.
When in the horizontal position the hopper entirely closes the upper
front part of the furnace; for feeding fuel into the furnace the fuel is
first charged on to the hopper when this is in the position shewn, and
the hopper is then tilted up so as to cause the fuel to fall on to the
upper set of grate bars, after which the hopper is again turned down
into the horizontal position. Below the vertical plate n is a horizontal
plate o¹ and a slit & is provided above this plate for the introduction of a
stoking bar into the fuel on the upper grate bars.
8
By the above described arrangement of the furnace with feeding
hopper and stoking apertures 8, 8', the fresh coal can be introduced
on to the fire, and the fire can be stoked without introducing cold air
above the burning fuel.
This construction of furnace grates is applicable with advantage to
steam boilers, puddling furnaces, forge furnaces, hot air furnaces,
brewery pans, gas retort furnaces, and to various other similar purposes.
Having thus described the nature of my Invention and in what
manner the same is to be performed, what I claim is :-
First. The before-described arrangement of inclined sets of grate bars
with notched or stepped ends and with provision of spaces between the
sets of bars for the introduction of stoking implements.
Second. The before-described arrangement for imparting a jogging
motion to the alternate grate bars by means of rocking shafts and levers
constructed and operating as set forth.
Third. The before-described arrangement of turning feeding hopper
for the periodical introduction of fuel into the furnace and for closing
the upper part of the furnace against the entrance of cold air.

page_text: Fourth. The employment of the plate o operating in combination
with the opening s¹ between the sets of bars, substantially as and for
the purposes set forth.
Fifth. I claim in combination the general arrangement of furnace
grates herein-before described with reference to the accompanying Sheet
of Drawings.
In witness whereof, I, the said Theodor Von Bolzano have hereunto
set my hand and seal, this Fifth day of November, in the year of
our Lord One thousand eight hundred and seventy-one.
A
THEODOR VON BOLZANO. (L.S.)