Improvements in or relating to the Ventilation of Drains.
Year: 1891

page_text: Date of Application, 16th June, 1891-Accepted. 8th Aug., 1891
COMPLETE SPECIFICATION.
Improvements in or relating to the Ventilation of Drains.
I, JOHN JONES, of 40 Sydney Street, Chelsea in the County of Middlesex,
Builder, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention relates more particularly to the ventilation of the drains of
buildings in that portion which is usually separated from the main drain by means
of a trap and examination manhole and will be best understood by reference to the.
accompanying drawings in which
Fig. 1 is a section of a building showing my system of drain ventilation applied
thereto.
Fig. 2 is an enlarged sectional view of one of the inspection manholes showing
also the air inlet into the drain.
Fig. 3 is a section on a further enlarged scale of the branch air-inlet detached.
Fig. 4 is a front elevation, Fig. 5 a plan partly in section and Fig. 6 a vertical
section of the fresh-air-inlet valve shown on a smaller scale as applied to the
general system in Figure 1.
Like letters indicate like parts throughout the drawings.
Ordinarily such a system of ventilation of drains as that to which this invention
applies is arranged with an air inlet-non-return valve A placed say half-way up one
of the walls of the building and the pipe B from which (as distinguished from the
present invention) leads directly into a closely covered or sealed manhole C from
which the air passes through the house drain D and eventually to the outlet E
which may or may not be provided with a cowl E' and which is usually carried
above the roof F as shown in Fig. 1, or at all events considerably higher than the
inlet.
By these existing means the air has been lost or reduced in quantity by reason
of the size of the manhole and has not satisfactorily fulfilled the purpose for which
it was introduced.
According to this invention instead of connecting the pipe B with the manhole C
as hitherto done I connect it directly with the drain D as shown in Figs. 1 and 2
by a suitable branch B' which is so shaped as to introduce the air into the drain D
in the direction indicated by the arrow Y which is the reverse of that in which the
sewage flows; the direction of the flow of the sewage is indicated by the arrows Z,
that is to say the air is initially introduced into D in a direction extending from
the spigot to the socket of any one of the lengths of the drain pipe D.
The drain channel or channels G in the manhole C I prefer to close in by means
of a self-sealing cover H constructed according to the Specification appertaining to
Letters Patent No. 1645500 originally granted to me and as the taking of the air
direct into the drain renders special ventilation of the manhole unnecessary I
preferably arrange this cover as shown in Figures 1 and 2 quite close to the said
channels so that the space wherein sewer gas can accumulate is reduced to a
minimum.
The manhole cover C¹ may either be a solid unperforated plate or a perforated
pla or grating, as shown in Fig. 2. I is the trap, J the clearing shaft and K the
out t to sewer all of ordinary construction.
On the air outlet side of the building there is sometimes another inspection
manhole C2 as shown in Figure 1 which may be closed-in in a manner similar to

page_text: that before described and which being at the higher end of the drain D need only
be shallow. The outlet pipe E as well as being connected with the drain D may
_also if desired as shown in Figure 1-be connected with the manhole C2 so as to
draw air and sewer gas therefrom.
The valve usually applied to a drainage system for the admission of the
circulating current of air and prevention of escape of sewer gas ordinarily consists
of a tale flap lying when closed nearly vertically and pivotted at the top so that
the valve may remain open while the air enters but may close the instant a
tendency to return current manifests itself. The objection to this form of valve
however is that it is not sufficiently sensitive as the full weight of the valve has to
be moved in its opening, the valve lifting upwards.
In constructing my improved valve as shown in Figures 4, 5 and 6 I make it of
one or more flaps A' (in the accompanying drawings there are two shown)
preferably of talc and each pivotted on an axis A3 which is vertical in one plane
but in the other diverges from the vertical line at its upper end as shown clearly in
Fig. 6. By this means the direct weight of the valve has not to be overcome when
it opens as each part of the valve has merely to turn on its hinge or pivot A³ like
a door and the sensitiveness of the valve is thus greatly increased; while the
inclination of the axis is sufficient to ensure the prompt closing of the valve
immediately upon the manifestation of a return current.
The casing A is provided with one or more internal vanes or deflectors A' so as
direct any sewer gas or return currents entering or rising up into the said casing
directly on to the flaps A¹ so that at the first puff the flaps will be closed on to
their seating AB.
The front of this apparatus may be protected by a grating A' in the usual
manner.
As are stops for preventing the flaps A' opening so far that they cannot recover
themselves. The flaps A' are preferably pivotted so far out of the true vertical
plane that when there is no draught either way they will just close of their own
accord.
If desired each of the flaps A¹ may be hinged on a truly vertical pivot but the
above described arrangement is preferred.
In respects other than those hereinbefore particularly described my improved
system of house drainage is similar to ordinary existing systems.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a house-drainage system the introduction of the ventilating air current
into the house drain between the air and sewer-gas outlet and the inspection
manhole substantially as described.
2. In a house-drainage system the introduction of the ventilating air current into
the house drain D between the air and sewer gas outlet E and the inspection man-
hole C and in a direction opposite to that of the flow of the sewage substantially
as described, and illustrated in the accompanying drawings.
3. For a house-drainage system a branch inlet or junction pipe such as B¹ con-
structed and arranged substantially as described and illustrated in Figure 3 of the
accompanying drawings.
4. In an air-inlet valve such as described hanging the flap valve on a vertical or
approximately vertical axis substantially as described.
5. In an air-inlet valve such as described forming the valve in two or more parts
each supported on a vertical or approximately vertical pivot substantially as
described and illustrated in Figures 4, 5 and 6 of the accompanying drawings.
6. The combination and arrangement of parts constituting the complete air-
inlet valve substantially as described and illustrated in Figures 4, 5 and 6 of the
accompanying drawings.

page_text: 7. The combination and arrangement of parts constituting the complete house-
drainage system substantially as described and illustrated in Figures 1 and 2 of the
accompanying drawings.
JT1001
JOHN JONES.
W. P. Thompson & Boult,
Agents for the Applicant.