IMPROVEMENTS IN FIRE-BARS FOR FURNACE GRATEO
Year: 1861

page_text: LETTERS PATENT to Ewing Pye Colquhoun and John Robert Thomson,
both of No. 1, Laurence Pountney Hill, in the City of London, for the
"Invention of "IMPROVEMENTS IN FIRE-BARS FOR FURNACE GRATEO"
PROVISIONAL SPECIFICATION left by the said Ewing Pye Colquhoun and
John Robert Thomson at the Office of the Commissioners of Patents,
with their Petition, on the 27th July 1861.
We, EWING PYE COLQUHOUN and JOHN ROBERT THOMSON, both of No. 1,
5 Laurence Pountney Hill, in the City of London, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN FIRE-BARS FOR FURNACE GRATES,"
to be as follows:-
These fire-bars are preferred to be of the general form of "fish-backed "iron
girders in order that great stiffness may be obtained with little weight of
material. They are of the kind usually termed moveable grate or furnace bars,
They are particularly applicable to the furnaces of steam boilers, and may be
actuated either by hand or by suitable machinery. They are to be moved
horizontally and partially vertically, and are to be supported by transverse
bearing bars having recesses or notches to receive their ends, and form proper
air spaces between them. The bars to be moved, which are to be each alter-
nate bar while the rest. remain stationary, are each to have a V-shaped notch
at one end and a clear running face where they rest upon the bearing bars at
the other, and they are to be actuated by a projecting rib or catch formed upon
one of the aforesaid transverse bearing bars which is placed at the front end of

page_text: the grate, and serves as a rocking shaft for this purpose. This rib or catch
takes into the aforesaid V-shaped notches at the end of the bars, and on
moving the said rocking shaft on its axis the bars receive therefrom a to-and-fro
and at the same time a slight up-and-down motion. These fire-bars may be
in two or more ranges longitudinally, each range being actuated by separate
bearing bars or shafts at their front ends by means of connecting rods, thus
producing the same combined to-and-fro and up-and-down movement of the
bars in each range. A socket for receiving the end of a lever is attached to
the foremost rocking shaft, by which motion is to be given to the whole system.
The effect of this operation results in attaining the objects of the Invention,
namely, preventing the formation of clinkers, thereby increasing the durability
of the bars, giving a more free access to the draught of air between the bars,
thereby increasing the heat of the fire, saving fuel, and also preventing the
formation of black smoke.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed 1
by the said Ewing Pye Colquhoun and John Robert Thomson in the
Great Seal Patent Office on the 27th January 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, EWING
PYE COLQUHOUN and JOHN ROBERT THOMSON, both of No. 1, Laurence
Pountney Hill, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of July, in the year of our Lord
One thousand eight-hundred and sixty-one, in the twenty-fifth year of Her reign,
did, for Herself, Iler heirs and successors, give and grant unto us, the said
Ewing Pye Colquhoun and John Robert Thomson, Her special licence that
we, the said Ewing Pye Colquhoun and John Robert Thomson, our exe-
cutors, administrators, and assigns, or such others as we, the said Ewing Pye
Colquhoun and John Robert Thomson, 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 of
IMPROVEMENTS IN FIRE-BARS FOR FURNACE GRATES," upon the condition
(amongst others), that we, the said Ewing Pye Colquhoun and John
Robert Thomson, our executors or administrators, by an instrument in
writing under
or their, or one of their hands and seals, should par

page_text: ticularly 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 we, the said Ewing Pye Colquhoun and John Robert
Thomson, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, reference being had to the Drawing
hereto annexed, and to the figures and letters marked thereon, that is
to say:-
Figure 1 represents a longitudinal section of a furnace shewing three rows
or sets of bars; Figure 2 also represents a longitudinal section, shewing only
two sets or rows of bars; and Figure 3, a transverse section of Figures 1
and 2.
The fire-bars we prefer to use are of the form of the well-known fish-backed
girders having a plain surface on both sides without shoulders at their ends,
as in the ordinary fire-bars, being formed with a V-shaped notch fat one end
and a plain surface g at the other. They are moved horizontally as well as
slightly vertically by means of a lever and socket e herein-after described, and
are supported by transverse bearing bars b and c, Figure 3, having recesses or
notches h, to receive the ends of the fire-bars and keep them at equal distances
apart, and form the necessary air spaces between them, or the bearers may be
made without notches, in which case the fire-bars would be furnished with a
projecting stud on their sides, so as to keep them asunder, and form the
required air spaces between them. The bars which are made to move are
each alternate bar, and these bars have the v-shaped notch or end f resting
in the notches h of the moveable bearer b, while those bars that are stationary
have the V-shaped end resting on the notches of the fixed bearers c. The bars
are preferred to be in two or more ranges, each range being supported by two
transverse bearing bars b and c, the front bearer 6 of each range of bars being
moveable, and the back bearing bar c being fixed. The front or moveable
bearing bar 6 of each and every range is connected together by a rigid con-
necting rod d. With the moveable bearing bar 6 nearest the furnace mouth
a socket e is cast, into which a hand lever (not shewn in the Drawing) is
placed, or it can be worked by any other suitable self-acting mechanical
arrangement, and by giving to it an up-and-down movement it will move the
bearer 6 and the connecting rod d, thus producing a combined to-and-fro
motion of all the ranges or rows of fire-bars in the furnace. The object of
moving the fire-bars is to free them from the dust that may accumulate in the

page_text: spaces between the bars, thus preventing the rapid formation of clinkers, and
allowing a free current of air to pass between the bars, thereby producing a
more perfect combustion of the fuel, and consequently obtaining from it a
greater amount of heat.
Having now described the nature of our said Invention, and the manner in
which the same is to be performed, we wish it to be understood that we do
not confine ourselves to the precise details of construction, as the same may be
modified-without departing from the principle or main feature of our Invention;
but what we do claim is, the making the front bearers of each range of fire-
bars moveable, and connecting them by a rod passing beneath the fire-bars in
the manner and for the purposes herein-before described and represented in
the accompanying Drawing.
In witness whereof, we, the said Ewing Pye Colquhoun and John
Robert Thomson, have hereunto set our hands and seals, this Twenty-
fifth day of January, One thousand eight hundred and sixty-two.
E. P. COLQUHOUN.
(L.B.)
JOHN ROBT. THOMSON. (L.S..)-