IMPROVEMENTS IN VENT OR CHIMNEY LININGS, AND IN SMOKE PREVENTIVE' AND VENTILATING APPARATUS CONNECTED THEREWITH
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by William Smith at the Office of
the Commissioners of Patents, with his Petition, on the 30th December
1859.
I, WILLIAM SMITH, of Kilmarnock, in the County of Ayr, North Britain,
Fire-clay Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN VENT OR CHIMNEY LININGS, AND IN SMOKE PREVENTIVE'
AND VENTILATING APPARATUS CONNECTED THEREWITH," to be as follows, that is
to say:-
This Invention relates to the arrangement and construction of vent or
chimney linings of fire-clay, or a composition thereof, as well as smoke preven-
tive and ventilating apparatus connected therewith, in such a manner as to
secure important advantages, as well in the original arrangement and con-
struction of the vents or chimneys and fire-places, as in the ultimate working of
the same.
According to this Invention each chimney has fitted into its bottom or lower
end, immediately above the part where the top edge of the grate joins up to the
lintel brace or upper portion of the mantel piece, a fire-clay lining piece, formed
with a wide oblong throat. to embrace the space over the fire grate. The lower
edge of this lining piece, or "oncome," as it is technically termed, is formed
with a horizontal flange all round, and the flange on the front edge is thus made
to answer as the lintel of the chimney piece, no other lintel being required.
This improved "oncome" being of oblong form and disposed with its shortest
dimension across the thickness of the wall in which the chimney is situated,

page_text: a saving is effected, by securing the non-necessity of cutting away any of the
structure of the masonry or mantel piece, whilst sufficient area is afforded for the
due covering in of the necessary space above the fire grate. The wide throat of the
lining or "oncome" is contracted upwards to the necessary area of the lining,
and the latter is then continued up by fitting in sections of lining of the proper
size, the first section of the lining having bottom edge flanges for building into
the masonry, thus forming a support, and preventing undue downward pres-
sure upon the "oncome." As a back smoke preventive a metal door is fitted
oncome," and so as to work in the interior of the lining. This
door has an open cast-iron framepiece fitted into the lining structure and
formed with a groove and checking piece all round for similar groove and
checking pieces upon the door to fit into. This secures a most accurate fit
and prevents all downdraughts. For ventilating purposes each lining piece
above the "oncome" is formed with a separate narrow ventilating thorough-
fare, and the bottom section having a lateral opening in it, air can thus pass
into a continuous ventilating thoroughfare from the apartment, and so ventilate
it in a most complete manner.
In the case of kitchen ranges, where flues of various kinds have to be pro-
vided for, and where the open space above the range is of considerable extent,
"oncomes" of a generally similar form are used for the ordinary fire draught;
but in addition to this, gathering flues are formed to convey the draught cur-
rents of the oven, boiler, and hot plate flues up outside the main "oncome,"
suitable lateral apertures are formed in the vent lining above the "oncome"
to receive the currents thus taken up independently of the main "oncome."