IMPROVEMENTS IN MOVEABLE GRATES FOR STEAM BOILER OR OTHER FURNACES
Year: 1869

page_text: LETTERS PATENT to John Hawthorn Kitson and John Kirby, both
of Leeds, in the County of York, Engineers, for the Invention of
"IMPROVEMENTS IN MOVEABLE GRATES FOR STEAM BOILER OR OTHER
FURNACES."
Sealed the 9th July 1869, and dated the 14th January 1869.
PROVISIONAL SPECIFICATION left by the said John Hawthorn
Kitson and John Kirby at the Office of the Commissioners of
Patents, with their Petition, on the 14th January 1869.
We, JOHN HAWTHORN KITSON and JOHN KIRBY, both of Leeds,
in the County of York, Engineers, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MOVEABLE GRATES FOR STEAM BOILER
OR OTHER FURNACES," to be as follows:-
The improvements consist of moveable fire-bars which are caused to
traverse the furnace from end to end on an upper tier at a gradual speed
according to the rate of combustion required, and when such bars have
traversed the whole length of the upper tier they are caused to fall on
a lower tier, along which they are returned to the point from which
they started, thus performing an endless circuit. This traversing of the

page_text: bars is effected by means of screw shafts acting directly upon the bars
themselves, which are also forced from the top tier to the lower tier, and
vice versa, by means of cams upon the screw shafts. The application of
these screws and cams and the form of the bars are suitable for every
description of furnace. The gearing actuating these screws may be 5
worked either by hand or power.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Hawthorn Kitson and John Kirby in the
Great Seal Patent Office on the 14th July 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN 1
HAWTHORN KITSON and JOHN KIRBY, both of Leeds, in the County of
York, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of January, in the
year of our Lord One thousand eight hundred and sixty-nine, in the 1
thirty-second year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said John Hawthorn Kitson
and John Kirby, Her special licence that we, the said John Hawthorn
Kitson and John Kirby, our executors, administrators, and assigns, or
such others as we, the said John Hawthorn Kitson and John Kirby, 2
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 the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for 2
"IMPROVEMENTS IN MOVEABLE GRATES FOR STEAK BOILER OF OTHER FURNACES,"
upon the condition (amongst others) that we, the said John Hawthorn
Kitson and John Kirby, our executors or administrators, by an instru-
ment in writing under our, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In- 8
vention, 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.

page_text: NOW KNOW YE, that we, the said John Hawthorn Kitson and Jolu
Kirby, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to tho
Drawing hereunto annexed, and to the letters and figures marked
thereon (that is to say) :-
This Invention consists in adapting to steam boiler and other furnaces
moveable grates composed of separate transverse fire-bars, which aro
caused to travel along the furnace from end to end on an upper tier or
guido at an uniform speed, depending upon tho rate of combustion
required, and when such bars have travelled the whole length of the
upper tier or guide they are caused to fall on to a lower tier or guide,
along which they are returned to the end from which they started, and
when there they are lifted up to the upper tier so as to be carried
forward a second time. All the bars will thus be made to perform an
endless circuit and be constantly moving forward.
The way in which this travelling of the bars is effected will be
understood by referring to the acconipanying Drawings, in which Fig. 1,
Sheet I., is a longitudinal section of a steam boiler furnace constructed
according to our improvements. Fig. 2, Sheet II., is a partial end
elevation and partial transverse section of the same.
The grate bars a, a, are carried forward by means of the screw shafts
b, b, acting directly upon the bars themselves, the ends of which fit
against the scrow shafts and are forced along as the latter are rotated.
The bars may be dropped from the top tier or guide to the lower tier
or guide by their own weight, or they may be pushed down and lifted
or raised up by means of cams c upon the screw shafts. This mode
of actuating the fire-bars by screws and cams is applicable for various
kinds of furnaces. The bevil toothed gearing for actuating these
screws is clearly shewn in the Drawing and may be worked by steam
If desired the bottom
power applied thereto in any convenient manner.
screws may be arranged to revolve at twice the speed of the upper
scrows, or the lower scrows may be made of a sharper pitch than the
upper ones so as to have only half as many bars a upon the lower tier
as on the upper tier, and thus give more freedom for the cinders to
fall through. If preferred the fire-bars may be moved forward by

page_text: means of cams without the intervention of screws by causing the cams
to act direct against the bars themselves.
This arrangement is shown in Sheet I., at Fig. 3, which is a section
representing so much of the furnace as is necessary to explain this
improvement.
5
The grate bars a, a, in this instance are made larger or wider at their
ends than at the middle, so that although the wide ends of the bars
will be contiguous there will at the same time be suitable interstices
between the bars at their other parts, so as to allow the ashes to drop
through and air to support combustion to pass through the grate. A 1
pair of cams c', c', are mounted or forged on the cross shaft dat the
end of the upper tier of bars. This shaft d is driven by suitable gearing
as in the former instance, and as these cams c', c', rotate they will act
against the last fire-bar in the tier and drive it forward, and of course
in so doing will drive forward all the other bars in front. At the end 1
of the race the bars will drop one by one on to the lower tier, or they
may be forced down in succession by the lever g, and may then be
driven back in the contrary direction in a similar manner by other cams
or by means of the lever e, Fig. 3, until they arrive at the front end of
the fire-place, when another or lifting cam or lever f will lift the bars 2
in succession up to the upper tier ready to be pushed forward again by
the upper cams c³, c. It should be understood that as the top or
pushing cam c rotates the first bar is raised by the lifting cam or lever f
at the time when the wide part of the pushing cam c retreats from
the bars, and thereby leaves space enough to receive a fresh bar from 2
below. It will be seen that the levers e, f, and g are linked together
by the rods i, , and are actuated by a pair of excentrics on the shaft d.
The lever for lifting the bars from the lower to the upper tier will
hold the bar up until the upper cam c¹ lays hold of it and pushes it
forward. The whole of the moveable fire-grate, together with the
gearing and other accessories, is mounted on a carriage provided with
wheels h, h, as shewn in the Drawing, so that it may be run in or out
of its place under the boiler when required.
The advantages of the above improvements are that there will be a
great saving of labor in stoking and minding the fires, the fuel is also a
consumed in a more economical and regular manner than heretoforo,
and as the fire is not being continually disturbed fuel of a cheaper
kind than the ordinary fuel may be employed. The construction of the

page_text: mechanism, moreover, admits of the working parts being repaired with
facility and at moderate expense.
Having now described our Invention of "Improvements in Moveable
Grates for Steam Boilers and other Furnaces," and having explained the
manner of carrying the same into effect, we claim as the Invention
scoured to us by Letters Patent as aforesaid, the adaptation to steam
boiler and other furnaces of moveable grates provided with separate
travelling bars, and constructed and operating in the manner herein set
forth.
In witness whereof, we, the said John Hawthorn Kitson and John
Kirby, have hereunto set our hands and seals, the Twelfth day
of July, in the year of our Lord One thousand eight hundred
and sixty-nine.