IMPROVEMENTS IN FIRE-BARS FOR STEAM BOILER AND OTHER FURNACES
Year: 1859

page_text: LETTERS PATENT to Henry Harden, of Dundalk, in the County of Louth,
Ireland, Locomotive Superintendent to the "Dublin and Belfast Junction.
Railway Company," for the Invention of "IMPROVEMENTS IN FIRE-BARS
FOR STEAM BOILER AND OTHER FURNACES."
Sealed the 5th July 1859, and dated the 8th January 1859.
PROVISIONAL SPECIFICATION left by the said Henry Harden at the
Office of the Commissioners of Patents, with his Petition, on the
8th January 1859.
I, HENRY HARDEN, of Dundalk, in the County of Louth, Ireland, Locomotive
Superintendent to the "Dublin and Belfast Junction Railway Company," do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN FIRE-
BARS FOR STEAM BOILER AND OTHER FURNACES," to be as follows:-
My Invention has for its object such an arrangement and construction of
fire-bars as will give a greater area for the admission of air and more evenly
distribute it to the fuel than those of ordinary construction, which are made so
that the air spaces between the bars are in straight lines parallel to each other,
which leave strips of fuel on the surface of each bar equal in dimension to its
length and breadth, without any direct supply of air.
Now my Invention consists in forming and arranging fire-bars so that the
spaces between them for the admission of air will pass in a zig-zag line, thus

page_text: breaking up the grate surface into a series of short parallelograms, each of
which is nearly surrounded by an air space, so that there are no considerable
lengths unbroken by air spaces as in the ordinary fire-bars.
I find that my improved fire-bars can be made of wrought iron as well as
cast iron, and that they may be made single and rivetted together in pairs or
double, so that when one side of a bar has become burnt or worn out it may be
turned upside down, thus diminishing the cost of renewal.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Harden in the Great Seal Patent Office on the
6th July. 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
HARDEN, of Dundalk, in the County of Louth, Ireland, Locomotive Superin-
tendent to the "Dublin and Belfast Junction Railway Company," send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 1
Patent, bearing date the Eighth day of January, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Harden, Her special license that I, the said Henry
Harden, my executors, administrators, and assigns, or such others as I
the said Henry Harden, 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 "IM-
PROVEMENTS IN FIRE-BARS FOR STEAM BOILER AND OTHER FURNACES," upon the
condition (amongst others) that I, the said Henry Harden, by an instrument in
writing, under my hand and seal, 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 Henry Harden, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement, and accompanying Drawings (that is to say):-
1

page_text: My Invention has for its object such an arrangement and construction of
fire or grate bars as will give a greater area for the admission of air and more
evenly distribute it to the fuel than those of ordinary construction, which are
made so that the air spaces between the bars are in straight lines parallel to
each other, which leave strips of fuel on the surface of each bar equal in
dimensions to its length and breadth without any direct supply of air.
Now my Invention consists in forming and arranging fire. or grate bars so
that the spaces between them for the admission of air will pass in a zig-zag
line, thus breaking up the grate surface into a series of short parallelograms,
each of which is nearly surrounded by an air space, so that there are no con-
siderable lengths unbroken by air spaces as in ordinary bars.
I find that my improved fire or grate bars can be made of wrought iron
as well as cast iron, and that they may be made single and rivetted together in
pairs or made double, so that when one side of a bar has become burnt or
worn out it may be turned upside down, thus diminishing, the cost of
renewal.
The particular manner in which I carry my Invention into effect is shewn
by the accompanying Drawings.
Figs. 1, 2, 3, and 4 represent respectively a longitudinal elevation, a longi-
tudinal section, cross section, and plan view of my improved fire-bars cast
together in pairs. The bars, when made single, are formed by a straight
piece (a), having projections (6) alternatively from each side; the double bars
exhibited by Figs. 1, 2, 3, and 4 are constructed in the same manner, except
that they are connected and form one piece at the ends and at certain points (c)
along their length to give strength and stiffness. Figs. 5, 6, 7, and 8 are
views corresponding respectively to Figs. 1, 2, 3, and 4, exhibiting double
reversible fire-bars; the single bar in this construction is formed by a straight
piece (a) with corresponding projections (b) on both sides opposite each other.
Single bars have to be arranged so that the projections on one bar will come
opposite the spaces between the projections on the adjoining bar. It will be
seen that the projections (b) extend across the vertical sides of the bar, so that
it can be turned and will present the same appearance either edge up. With
this form of bar I make holes (d) through the enlarged parts of the bar as
shewn, for the passage of air to the fuel. These bars as well as those shewn
by Figs. 1, 2, 3, and 4, though they may be used single, are more convenient
when cast or rivetted together in pairs. Bars similar to those shewn by Figs. 1,
2, 3, and 4, may be made reversible by extending the projections (b) across
the vertical sides (a). My improved fire-bars are particularly advantageous
in locomotives when burning coal, and in the Drawings the examples are

page_text: supposed to be applied to locomotive fire-boxes, but they are also applicable
to other furnaces.
I have now particularly described the nature of my Invention, and the
manner in which it may be carried into effect, and wish it to be understood
that I claim fire or grate bars for steam boiler and other furnaces constructed
and arranged substantially as herein-before described.
In witness whereof, I, the said Henry Harden, have hereunto set my
hand and seal, this First day of July, in the year of our Lord One
thousand eight hundred and fifty-nine.
HENRY HARDEN. (L.S.)