Year: 1888

page_text: Date of Application, 16th Jan., 1888
Complete Specification Left, 15th Oct., 1888
Complete Specification Accepted, 16th Nov., 1888
I, EZRA SPENCER MCCLELLAN of 108 Haledon Avenue, Paterson, in the State
of New Jersey, United States of America, Doctor of Medicine, do hereby declare
the nature of this invention to be as follows:
-
This invention relates to an air valve and its case and connections that are to be
applied to the sewer side of a trap, to admit air into the sewer or drain pipe when-
ever there is a minus air pressure in the said sewer or drain pipe so as to prevent the
water seal in the trap being drawn out of the same and thereby allowing the gases
from the sewer to escape.
In plumbing appliances it is usual to introduce a trap below the water closet, basin
or bath, in the pipe leading to the sewer or drain pipe, so as to seal the pipe by the
water contained in such trap and prevent the sewer gases escaping..
If there is a rush of water down or along the main or sewer pipe, past the end of
the branch thereof that contains the trap, the air is often partially expelled and the
atmospheric pressure forces a portion of the water in the trap out into the sewer
pipe, and when the pressures are equalized the sewer gases escape through the trap
because the water does not seal the same. By applying my improvements upon the
branch or sewer pipe, at the sewer side of the trap, air is admitted so that no minus
pressure is produced in the sewer pipe and the water of the trap cannot be drawn out
or syphoned.
In my improvements I use a case that is connected by a short pipe with the sewer
pipe, and such case is overhanging so as to have an upward opening in the lower
part thereof, and through this opening an air valve is introduced said air valve being
light and in the shape of an inverted cylindrical cup, and there is an open thimble
introduced within the valve and securely fastened to the case, so as to form an
annular trough around it and within the case for mercury, into which the lower edge
D27

page_text: of the cup shaped air valve passes, and the same seals the valve to prevent the escape
of gases, but when there is any minus pressure in the sewer pipe the air valve is
lifted by the atmosphere as it rushes in to equalize the pressure. The lower part of
the thimble, or a circular follower fitted to the same is made of openwork to admit
the air to pass freely but to protect the air valve. The cup shaped air valve is guided
by a stem or by ribs on the inside of the case or by both, and there is an opening
through the case and a cup on the outside so that the mercury can be introduced into
the trough after the parts are attached in place.

page_text: I, EZRA SPENCER MCCLELLAN, of 108 Haledon Avenue, Paterson, in the State of
New Jersey, United States of America, Doctor of Medicine, 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 to an air valve and its case and connections that are to be
applied to the sewer side of a trap, to admit air into the sewer or drain pipe when-
ever there is a minus air pressure in the said sewer or drain pipe, so as to prevent the
water seal in the trap being drawn out of the same and thereby allowing the gases
from the sewer to escape.
In plumbing appliances it is usual to introduce a trap below the water closet, basin
or bath, in the pipe leading to the sewer or drain pipe, so as to seal the pipe by the
water contained in such trap and prevent the sewer gases escaping
If there is a rush of water down or along the main or sewer pipe, past the end of
the branch thereof that contains the trap, the air is often partially expelled and the
atmospheric pressure forces a portion of the water in the trap out into the sewer pipe,
and when the pressures are equalized the sewer gases escape through the trap because
the water does not seal the same. By applying my improvements upon the branch
or sewer pipe, at the sewer side of the trap, air is admitted, so that no minus pressure
is produced in the sewer pipe and the water of the trap cannot be drawn out or
syphoned.
In my improvement I use a case that is connected by a short pipe with the sewer
pipe, and such case is overhanging so as to have an upward opening in the lower
part thereof, and through this opening an air valve is introduced said air valve being
light and in the shape of an inverted cylindrical cup, and there is an open thimble
introduced within the valve and securely fastened to the case, so as to form an annular
trough around it and within the case for mercury, into which the lower edge of the
cup shaped air valve passes, and the same seals the valve to prevent the escape of
gases, but when there is any minus pressure in the sewer pipe the air valve is lifted.
by the atmosphere as it rushes in to equalize the pressure. The lower part of the
thimble, or a circular follower fitted to the same is made of openwork to admit the
air to pass freely but to protect the air valve. The cup shaped air valve is guided by
a stem or by ribs on the inside of the case or by both, and there is an opening
through the case and a cup on the outside so that the mercury can be introduced
into the trough after the parts are attached in place.
In the drawings, Figure 1 is a vertical section of my improved air-vent; Figure 2
is a sectional plan at the line a, a; Figures 3 and 4 are sections of modifications in
the details of construction.
The hollow case A is of a suitable size according to the size of the waste pipe to
which it is to be connected by the pipe C. I prefer to make a nipple 2 upon the
case A, usually at one side or upon the lower part of the case, to receive the screw.

page_text: ring 3 of the union joint so that the case can easily be connected to or disconnected
from the pipe C; and I remark that I usually place the air inlet above the trap in the
sewer or waste pipe and run the pipe C down from the case A to the upper part of
the trap, so that the air may draw into the sewer or drain in such a manner as to
prevent the siphon action.
The case A is supported in any suitable manner. I have shewn slotted flanges B
for receiving screws that pass into the wall or partition.
The case A has a downwardly projecting rim 4 that is of a size sufficient for the
passage through it of the air valve D, which valve is provided with a guide stem 5,
and within the rim 4 is introduced the movable thimble E, the sides of which are
inclined inwardly, so that a trough is formed between the outer surface of the
thimble and the inner surface of the rim 4 for the reception of the mercury 15,
and this mercury forms a seal around the lower edges of the cup-shaped air valve D, and
this air valve is preferably of thin sheet steel, the sides of which are cylindrical, and
it is sufficiently light to lift readily by atmospheric pressure when any minus pressure
exists within the case A, and the air passes beneath the edges of this inverted cup-
shaped valve to render the pressure within the waste pipe equal to the external
atmospheric pressure, and thereby stop any siphoning action.
The movable thimble E may have a screw upon its edges, so as to be screwed into
the inside of the rim 4, as seen in Figure 3, or it may be made with a flange and
channel for the reception of a rubber packing ring 6, which is held in place by a
follower F, screwed into the inside of the rim 4 as seen in Figure 4, or pressed into
place by separate screws 7, as seen in Figure 1. In either instance the centre portion
of the follower F is openwork, that freely admits the passage of air, but protects the
air valve from injury.
The stem 5 may pass upward, as in Figure 1 and be guided by the bridge 8, or it
may pass downwardly as in Figure 3 and be guided by a bearing or bridge 9, at the
centre of the follower F as seen in Fig. 3, or it may pass both up and down through
the guides 8 and 9 as seen in Figure 4.
It is generally preferable to provide wings 10 upon the outer surface of the
thimble E and within the air valve D, to aid in keeping the air valve in its proper
position, or there may be vertical wings 11 projecting from the inner surface of the
hollow case A and at equal distances around the air valve to aid in guiding or
steadying the same, as seen in Figure 3, or both the wings 10 and 11 may be made
use of.
The joint between the thimble E and the rim 4 is to be made tight, because the
same is at the bottom of the mercury trough, and at one side of the rim 4, and outside
the case I provide a mercury cup 12 having a hole extending from the bottom thereof
through the case A into the trough for the mercury 15, and the top of this cup is to
be at the proper height to correspond with the mercury level, so that the apparatus
can be transported and put up into place without any mercury in the trough, and
thereafter the mercury can be supplied into the cup 12 and it runs into the trough to
the proper height.
A screw plug 13 is by preference introduced into the hole that leads from the
cup into the mercury trough, so that the mercury will be properly confined within
the trough and be of the proper depth for the lower edge of the air valve to dip
into it.
I prefer to use mercury in the cup, but do not limit myself to the same.
The parts of this apparatus may be rendered rust-proof by the so called Bower-
Barff process.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
1. The combination, with the inverted cup shaped air valve, of the hollow case A,
having a connection for the pipe leading to the sewer side of the trap or drain, and
a rim with an opening through which the air valve is inserted, a hollow thimble

page_text: beneath and within the cup shaped air valve and connected to the rim, and a liquid
in the annular cup between the rim and the thimble, substantially as set forth.
2. The combination, with the inverted cup shaped air valve, of the hollow case
having an opening in the bottom thereof for the admission of the air valve, a movable
open hollow thimble within and below the inverted cup shaped air valve, a stem upon
the air valve and a guide or guides for the same, and mercury in the annular trough
around the thimble substantially as set forth.
3. The combination, with the inverted cup shaped air valve, of a case having an
opening through which the air valve is introduced, a pipe leading from the case to
the sewer or drain, an open hollow thimble within the air valve, and a ring for
securing the thimble firmly within the rim of the case, and mercury in the annular
trough around the thimble, substantially as set forth.
4. The combination, with the inverted cup shaped air valve, of a case having a rim
and opening through which the air valve is introduced, a movable open hollow
thimble within and below the air valve and having a ring around its lower end
passing into the rim of the case, and a follower having air inlet openings through it
and secured to the rim of the case substantially as set forth.
5. The combination, with the inverted cup shaped air valve, of a case with an
opening on the under side through which the air valve is introduced, a separate open
thimble within the air valve, a ring follower for securing the thimble to the case, and
mercury in the annular trough around the thimble and into which the lower edges of
the air valve pass, and guide wings to aid in retaining the air valve in position as it
rises or falls substantially as specified.
6. The combination, with the inverted cup shaped air valve, of a case having an
annular mercury trough into which the edges of the air valve dip, an open thimble
forming an air inlet opening through the case and below the valve, and a supply cup
outside the case with a hole through which the mercury is introduced into the trough,
and a plug for the supply cup, substantially as set forth.
Dated this 15th day of October 1888.
E. S. MCCLELLAN.
By Brewer & Son,
33, Chancery Lane, London,
Patent Agents.