Year: 1897

page_text: PROVISIONAL SPECIFICATION.
I, FREDERICK THOMAS GRANT, Assistant Borough Surveyor of Maidstone, in
the County of Kent, do hereby declare the nature of this invention to be as
follows:-
This invention relates to air inlets for drains and consists in constructing them
in the following manner :-
A pipe or chamber connected below directly or by pipes with the drain is closed
at the top by a removable air tight cover. This chamber has a lateral opening
about which is a seating for a self closing flap, such as mica, silk and the like, and
exteriorly of the seating the said opening runs into an upwardly extending channel,
the bottom of which is inclined towards the opening into the chamber aforesaid.
This channel leads above into a rising pipe or chamber at the upper end or part of
which is a grating preferably in one of its side faces. This apparatus, if set
in a path with its cover level with the surface of said path, may be so placed that
the rising pipe of suitable shape and size may be built into the face of a house
wall or other wall, or it may rise in front thereof or independently, the grating
being at all times so far above the path or ground level that it cannot become
choked by mud or the like. The flap being within the lower chamber cannot be
reached by mischievous persons and stones or other matter that may be dropped
through said grating cannot lodge in front of said flap since the incline of the
floor of the channel thereto is such that they will roll or slide into the lower
chamber. It is desirable to incline the seating for the flap somewhat from the
vertical so that the flap may close more surely against it and not, it caught open
by a back draught be forced further open thereby.
The air tight cover allows of inspection and repair of the flap, also inspection
and clearing of the interceptor and the testing of the drain.
The grating with its chamber or pipe and channel with the flap seating and
Hap may be made apart from the inspection or lower chamber with its cover and
may be used for ventilating inlet to a manhole built over the interceptor of the
drain.
T
1007
Improvements in Air Inlets for Drains,
I, FREDERICK THOMAS GRANT, Assistant Borough Surveyor of Maidstone, in
the County of Kent, do hereby declare the nature of this invention and in what
Price 871

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
This invention relates to air inlets for drains or sewers and consists in con-
structing them in the following manner.
This
A pipe or chamber connected below directly or by pipes with the drain is closed
at the top by a removable air tight cover. This chamber has a lateral opening
about which is a seating for a self closing flap, and exteriorly of the seating
the said opening runs into an upwardly extending channel, the bottom of
which is inclined towards the opening into the chamber aforesaid.
channel leads above into a rising pipe or chamber at or near the upper end or part of
which is a grating preferably in one of its side faces. This apparatus, if set
in a path with its cover level with the surface of said path, may be so placed that
the rising pipe of suitable shape and size may be built into the face of a house
wall or other wall, or it may rise in front thereof or independently, the grating
being at all times so far above the path or ground level that it cannot become
choked by mud or the like. The flap being within the lower chamber cannot be
reached by mischievous persons and stones or other matter that may be dropped
through said grating cannot lodge in front of said flap since the incline of the
Hoor of the channel thereto is such that such stones or matter will roll or slide into
the lower chamber. It is desirable to incline the seating for the flap somewhat from
the vertical so that the flap may close more surely against it and not, if caught open
by a back draught be forced further open thereby.
It is further desirable to place just below the edge of the flap when in its closed
position a rib on the wall of the chamber to deflect back draught and prevent
possibility of such draught passing between the flap and its seating in such a
way as to raise the flap from its seating.
The air tight cover allows of inspection and repair of the flap, also inspection
and clearing of the interceptor and the testing of the drain.
The grating with its chamber or pipe and channel with the flap seating and
flap may be made apart from the inspection or lower chamber with its cover and
may be used for ventilating inlet to a manhole built over the interceptor of the
drain.
The construction is illustrated in the annexed drawing in which Fig. 1 is a
vertical section on line 1-1 of Fig. 2. Fig. 2 is a section on line 2-2 of Fig. 1.
Fig. 3 a side elevation and Fig. 4 a plan view of the lower chamber with the
cover and rising pipe or chamber removed.
A represents the lower chamber with a seating at a for the cover B and with
ribs at c, c¹ for a slide C which may be in the form of a grid preferably of brass
making a seating for the flap D. O is a lip on the seating C to prevent back
draught lifting the flap D. The chamber A may be made of cast iron in one piece
with the part A¹ into the upper end of which the rising pipe or upper chamber E
is fitted. This chamber E may be also of cast iron open below and consisting
of a back wall, two side walls and a top. The front E¹ of chamber E is removable
the upper part of this front forming the grating F. G represents a lug on each
side of the front E' which bears against the side walls of E, front E¹ bears, and H
is a screw or pin for fastening the front to the top of chamber E. The front E¹
when in position is secured by the insertion of the cover B which may be luted
with red lead and grease or otherwise and secured by screws J J. The slide C is
also secured in place between the ribs c c¹ by the cover B. The flap D) is pre-
ferably an aluminium plate and is suspended on two hooks K K projecting from
the slide C. The openings between the cross bars of the slide C are sufficiently
large to let pass stones or matter that might be maliciously or otherwise passed
through the grating F.
The preferred manner of arranging this device is also illustrated in the drawing
where M represents a wall and N a foot path. P P are lugs on part E for the
better holding of the same in the wall M.

page_text: Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim
is:-
1. An air inlet device for drains and sewers in which the air controlling flap
seats against a seating in such position relative to the exterior air inlet grating
that it cannot be reached or injured therefrom substantially as set forth.
2. The construction whereby the air controlling flap is contained in the chamber
A and seats against a seating in the side of said chamber whence a rising pas-
sage with inclined floor passes to an upper chamber provided with the exterior
air inlet grating.
3. The construction of air inlet device substantially as herein described in
such a manner that it may be set in or at a wall with the cover of chamber A
at the ground level and the grating F at a distance above the ground, the flap D
being within the chamber A.
4. An air inlet device constructed substantially as and for the purpose set
forth.