IMPROVE- MENT. IN FIRE-GRATES AND FURNACES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Archibald Craig at the Office of
the Commissioners of Patents, with his Petition, on the 31st January
1867.
I, ARCHIBALD CRAIG, of No. 9, Mincing Lane, in the City of London,
Merchant, do hereby declare the nature of the. said Invention for "IMPROVE-
MENT. IN FIRE-GRATES AND FURNACES," to be as follows:-
The said improvements relate to means for economizing the consumption
of fuel in the grates or fire-places of dwelling houses, and in stoves and other
fire-grates and furnaces, and consists chiefly in the employment of adjustable
bars, plates, or other devices which may be arranged to act in combination
with the ordinary under grate bars to regulate or prevent the admission of air.
between the same. The said adjustable devices facilitate the lighting of fires
in the said fire-grates or furnaces, and also allow the ashes and other in-
combustible portions of the fuel to be easily and conveniently removed. The
adjustable bars are placed below and parallel with the fixed or ordinary bars
of a fire-grate or furnace. The said adjustable bars are constructed of the
proper number, width, and distance apart to close the apertures between the
said fixed bars, or to open the said apertures to their full extent when the
same is desirable. The adjustable bars may be arranged to slide in grooves
or guideways formed in any convenient portion of the grate or furnace, and
they can be made to move either from side to side or from the back to the
front of the grate according to the construction of the same. Instead of
being constructed to slide the adjustable bars may be pivotted or hinged below

page_text: the fixed bars in such a position that they can be turned up to close the
apertures between the said fixed bars, and can be lowered to open the said
apertures to any desired extent. Both sets of grate bars may be made
adjustable, and arranged to slide one over the other in either direction. This
arrangement is more especially adapted for employment in furnaces for burning
coal of a description liable to produce clinkers, which are broken and removed
by the sliding bars. An iron plate or shutter may be employed below the grate
or furnace instead of the set of adjustable bars, which plate may be supported
to turn upon hinges, or may be arranged to slide or draw out from under the
grate. This plate or shutter is advantageously applied to grates wherein the
bottom is formed of fire-clay and perforated with holes or slits for the admission
of air. The adjustment of the bars, plates, shutters, or other devices may be
effected by means of handles, levers, screws, or other suitable and convenient
mechanism. The back of the grate may be provided with a number of holes
furnished with adjustable covers, by which the holes may be opened or closed-
at pleasure. When a fire is to be lighted in the said grate these holes are
opened, and the apertures in the bottom of the grate may be opened at the
same time. By this means an ample supply of air is obtained through the
bottom and rear of the grate, which may be diminished or entirely stopped
when found desirable. The covers of the holes in the back of the said grate
may be made to open and close simultaneously with the adjustable bars or
shutter, or may be operated by a separate lever or other mechanism.
Chambers may be provided in connection with the fire-grate or furnace to
collect the heat, which may be distributed through suitable passages and
ventilators to any part of a dwelling house or other building.