IMPROVEMENTS IN FIRE-BARS OR FURNACE GRIDS
Year: 1863

page_text: LETTERS PATENT to Daniel Mylrea, of Church, near Accrington, in the
County of Lancaster, Millwright and Engineer, for the Invention of
"IMPROVEMENTS IN FIRE-BARS OR FURNACE GRIDS."
Sealed the 9th October 1868, and dated the 11th April 1868.
PROVISIONAL SPECIFICATION left by Daniel Mylrea at the Office of
the Commissioners of Patents, with his Petition, on the 11th April
1863.
I, DANIEL MYLBEA, of Church, near Accrington, in the County of Lan-
caster, Millwright and Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN FIRE-BARS OR FURNACE GRIDS," to be as
follows:-
I make the cross bars of a waved or corrugated shape, with a groove on the
upper surface to catch or collect the ashes from the fuel, which ashes being a
non-conductor of heat preserves the bars from being soon consumed or burnt,
and also prevents the coals from clinkering. I cast the side bars and cross
bars together, so as to form a framework or grid for the bottom of the furnace,
and I make the side bars or frame either straight or corrugated, but in either
case I make a groove on the surface for the collection of the ashes. This
plan enables me to make the bars much lighter than the usual form, as well
as economising fuel and metal, and preventing the clinkering of the coals.
The corrugated surface of the bars, by presenting the greatest amount of
surface to the action of the atmosphere, keeps them cool.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Daniel Mylrea in the Great Seal Patent Office on the
10th October 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DANIEL
MYLREA, of Church, near Accrington, in the County of Lancaster, Millwright
and Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of April, in the year of our Lord One
thousand eight hundred and sixty-three, in the twenty-sixth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Daniel Mylrea, Her special license that I, the said Daniel Mylrea, my executors,
administrators, and assigns, or such others as I, the said Daniel Mylrea, 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 FIRE-BARS OR FURNACE
GRIDS," upon the condition (amongst others) that I, the said Daniel Mylrca,
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 YF, that I, the said Daniel Mylrea, 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 following statement
(that is to say) :-
:-
I make the cross bars of a waved, zig-zag, or corrugated shape, either
circular or angular, with a groove on the upper surface to catch or collect
small dust from the ashes from the fuel, which dust being a non-conductor of
heat preserves the bars from being soon consumed or burnt, and also prevents
the coals from clinkering.
In one arrangement I cast the side bars and cross bars together, so as to
form a framework or grid for the furnace, and make the side bars either
straight or corrugated, but in either case there is a groove or recess on the
surface of the side and cross bars for the collection of the dust or ashes.
This plan enables me to make the bars much lighter than the usual form, as

page_text: well as economising fuel and metal, and preventing the clinkering of the coals.
The corrugated or zig-zag surface of the bars, by preventing the greatest
amount of surface to the action of the atmosphere, keeps them cool.
These improvements will be clearly understood by referring to the figures
and letters on the accompanying Sheet of Drawings, in which Fig. 1 is a side
view, Fig. 2 a plan, and Fig. 3 an end view, of my improved fire-bars or
furnace grids drawn to a reduced scale; Figs. 4 and 5, are top and bottom
views of part of one of the fire-bars; and Fig. 6, a vertical section of part of
the same. In this arrangement there are six fire-bars or furnace grids a, but
only one drawn complete, the others being in outline; each bar is formed of
two outer side bars b, and a number of corrugated or serpentine cross bars c
cast to them. The centro bearers are shewn at d, they are bolted together by
the bolts e, and have spaces f for the tie bars. In the top of the side and cross
bars there are recesses or grooves g, Fig. 4, all connected together for
collecting or catching the small dust from the ashes, and at the bottom of
each cross bar there is a thin rib h, Figs. 5 and 6, which rib may be
straight or corrugated, but I prefer the straight rib, as in conjunction with the
corrugations of the bar a more irregular surface is formed, which has the effect
of causing the draught of air to rebound from the front of one rib to the back
of the one adjoining, and thereby keeping all parts of the bar equally cool,
and as the bar is cast in one piece, it is of great strength, and allows the cross
bars to be very light and shallow, which enables the top surface of the bar to
be kept as cool as possible by the admission of fresh cold air as near the
surface of the furnace as can be obtained. Each of the fire-bars or grids may
be made of any length and width, and any number may be used, according
to the dimensions of the furnace, and the cross bars may also be placed in a
diagonal direction, and the corrugations formed of varied curves or angles
in any desired manner.
I modify the arrangement by making the longitudinal or side bars of a
corrugated form, and use either the transverse corrugated bars, or a series of
longitudinal corrugated bars, with as many cross bars or tie pieces as may be
required, the corrugated parts being cast all in one piece, or separately as
single bars. The recesses d collect the dust or ashes, which being a non-
conductor of heat, prevent the burning or melting of the bars, and tho
corrugated form of the bars enable, them to be made very strong and light,
with a large area of space for the supply of air, which not only keeps the
bars cool, but maintains the fuel in such an intense combustion as to prevent
the formation or accumulation of clinkers.
Having now described the nature and particulars of my said Invention, and

page_text: the manner in which the same is to be performed, I desire it to be understood
that in the fire-bars or furnace grids for furnaces I claim the formation of
the bars of a corrugated or any zig-zag shape, either cast separately or all in
one piece, and the forms of the grooves or recesses at the top of the bars, so
that all the grooves are connected; and also the general arrangement of
the separate or compound bars, as herein described and illustrated in the
accompanying Sheet of Drawings.
In witness whereof, I, the said Daniel Mylrea, have hereunto set my
hand and seal, this Eighth day of October, in the year of our Lord
One thousand eight hundred and sixty-three.
Signed, sealed, and delivered, by the
within-named Daniel Mylrea, in
the presence of
E. J. HUGHES,
Patent Agent,
Manchester.
DANIEL MYLREA. (L.S.)