VENTILATING ROOMS BY MEANS OF A CHIMNEY OR SHAFT
Year: 1886

page_text: Date of Application, 8th Nov., 1886.
Complete Left, 21st Dec., 1886.
Complete Accepted, 25th Jan., 1887.
I, SAMUEL SINCLAIR ROBSON 13 Claremont Terrace Sunderland in the County of
Durham Wire Rope Manufacturer, do hereby declare the nature of this invention for
VENTILATING ROOMS BY MEANS OF A CHIMNEY OR SHAFT to be as follows:-
To carry off foul air from dwelling-rooms an opening is frequently cut into the
chimney near the ceiling, but in consequence of the top of the chimney being narrower
than the lower part smoke is liable to issue from such opening. For instance say an
ordinary house chimney measures 14 in. x 10 in. equal to 140 square inches, and the
cowl or pot upon it is only 9 in. x (by) 9 in. or 81 square inches, it is clear that the
140 square inches of smoke and hot air from the fire pressing out at the top will leave
no room for the admission of air through the ventilator. I therefore propose to remedy
this by contracting the chimney below the ventilator to a slightly less area than that
of the cowl or chimney pot cither by placing a plate across the chimney or in some other
way such plate to have an opening large enough for a chimney-sweeper's brush to
pass freely through but being smaller than the cowl. This plate may have a circular
or oval hole of 7 or 8 inches diameter, with an area of (say) 50 square inches as
compared with a cowl of 80 inches area, leaving a margin of 30 square inches for
ventilation. In practice I find this ample and sufficient to cause a strong current of
air to pass through the ventilator whether the chimney is heated by a fire or not, and
so keeping the room free from deleterious air. In this arrangement there is no
danger of smoke issuing from the ventilator as there is always a current of air into the
chimney through that aperture.

page_text: COMPLETE SPECIFICATION.
An Improvement in the Ventilation of Dwelling Rooms.
I, SAMUEL SINCLAIR ROBSON of 13 Claremont Terrace Sunderland in the County
of Durham Wire Rope Manufacturer do hereby declare the nature of my invention
for VENTILATING ROOMS BY MEANS OF A CHIMNEY OR SHAFT and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :—
To carry off foul air from dwelling rooms an opening is frequently cut into the
Chimney near the ceiling, but in consequence of the top of the chimney being narrower
than the lower part smoke is liable to issue from such opening.
For instance say an ordinary house chimney measures 14 inches by 10 inches equal
to 140 square
inches area, and the cowl or pot upon it is only 9 inches by 9 inches, or
81 square inches area, it is clear that the 140 square inches of smoke and hot air from
the fire pressing out at the cowl on the top will leave no room for the admission of air
through the ventilator.
I therefore propose to remedy this by diminishing the internal area of the chimney
below the ventilator to a slightly less area than that of the Cowl or Chimney-pot,
either by placing a plate, which I call a Contractor, across the Chimney or in some
other way; such plate or contractor to have an opening smaller than that of the Cowl,
but large enough to allow a chimney sweeper's brush to pass freely through.
This plate or contractor may have a circular or oval hole of 7 or 8 inches diameter
with an area of say 50 square inches as compared with a cowl of 80 square inches
area leaving a margin of 30 square inches for ventilation.
In practice I find this ample and sufficient to cause a strong current of air to pass
through the ventilator, whether the chimney is heated by a fire or not, thus freeing
the room from deleterious air. In this arrangement there is no danger of smoke
issuing from the ventilator as there is always a current of air into the chimney through
that aperture.
The ventilator or opening into the chimney may be 9 inches by 3 inches or any
other convenient size. It must be in the same flue as the contractor but above it and
should be near the ceiling of the room to be ventilated, or if preferred a pipe or tube
may be carried through the ceiling and thence into the Chimney so contracted.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is:
The improved ventilation of rooms by contracting the internal area of the Chimney
or shaft below the ventilator as herein before described.