AN IMPROVED TRAP AND GRATING FOR DRAIN AND SEWER INLETS
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery
Lanc, in the County of Middlesex, Patent Agent, for the Invention
of "AN IMPROVED TRAP AND GRATING FOR DRAIN AND SEWER INLETS."
-A communication from abroad by John Aldrich White, of
Concord, in the County of Merrimack, and State of New Hamp-
shire, United States of America.
Sealed the 7th April 1876, and dated the 29th December 1875.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 29th December 1875.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for " AN IMPROVED TRAP AND GRATING FOR DRAIN AND
SEWER INLETS," to be as follows :—
The object of this Invention is to provide a simple and effective trap
for sewers, drains, cesspools, and such like, and consists of a grating or
cover supported by a ring or base, and so constructed that the most of

page_text: the water wu pass under the cages of the cover instead of turouga the
grating.
One of the principal advantages of this arrangement is that the area
of the opening for the water to pass through into the catch basin is
greatly increased.
Another advantage is that sticks or other matter floating upon the
water will be prevented by the cover from passing into the catch basin,
and yet they will not clog the water, as is often the case in ordinary
gratings. Connected with and supported by this ring or base is a
conical cylinder or chute, at the bottom of which is a valve so arranged
that when closed, it will completely cover the bottom of the chute,
being held in that position by means of a weight. This arrangement of
chute and valve may be attached to round, oval, square, or in fact, rings
and covers of almost any design or style.
According to this Invention the conical cylinder or chute is provided
with a flange fitting into a base ring, and by which said cylinder or
chute is supported. The lower end of the chute is preferably bevelled
on one side, and to this bevelled part is hinged the flap or valve. The
weight is attached to the valve in such a manner as to keep the valve
closed against the lower end of the cylinder when the weight of the water
is not sufficient to force it open. The valve is grooved or flanged around
its outer edge to fit the bottom of the cylinder to which it is to be
attached, so that when said valve is in its place the weight will press
the valve up against the edges of the cylinder. The grate or cover rests
upon uprights which are supported by the base ring, and which may be
made to or a part of or simply rest upon the base ring or may be
attached to a separate ring.
When water passes through or under the grate in the trap it
accumulates until a sufficicnt quantity is gathered to overbalance the
weight, when the valve opens into the catch basin or sewer, discharging
the water, and allowing the weight to bring the valve back to place
again. The channelled edge of the valvo will hold sufficient water to
make an air-tight joint, and as the water which flows through the trap
is always more or less dirty, and holds more or less sand in suspension,
the sediment which will be deposited will make an air-tight joint, even
after the water has evaporated.

page_text: When storm waters are flowing rapidly into the catch basin of course
the valve will be held open by the volume of water, but as the flow
ceases the weight causes the valve to close, retaining a small quantity
of water in the channels around the edge of the valve. As this water
evaporates sediment will be deposited, as before explained, sufficient to
close the joint against the passage of air or sewer gas.
The weight is made of such a shape as to take the least room possible
in the catch basin, and so that by removing the grating or cover the
trap may be lifted out of the base ring in case it may become necessary
for repairs or any other purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Scal
Patent Office on the 15th June 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of December, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Alexander Melville Clark,
Her special license that I, the said Alexander Melville Clark, my
executors, administrators, and assigns, or such others as I, the said
Alexander Melville Clark, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "AN IMPROVED TRAP AND GRATING FOR DRAIN
AND SEWER INLETS," a communication to me from abroad by John
Aldrich White, of Concord, in the County of Merrimack, and State of
New Hampshire, United States of America, upon the condition (amongst
others) that I, the said Alexander Melville Clark, my executors or
administrators, by an instrument in writing under my, or their, or one of

page_text: valve closed against the lower end of the cylinder when the weight of
the water is not sufficient to force it open. The valve E is grooved or
flanged around its outer edge, in the manner shown, to fit the bottom
of the cylinder to which it is to be attached, so that when said valve is
in place, as shown at D, the weight F will press the valve up against
the edges of the cylinder. The grate or cover G rests upon uprights H
which are supported by the base ring C, and which may be made to
form a part of, or simply rest upon, the base ring, or may be attached to
a separate ring, as shown in the Drawings.
When water passes through or under the grate into the trap, it
accumulates until a sufficient quantity is gathered to overbalance the
weight F, when the valve opens into the catch basin or sewer, dis-
charging the water and allowing the weight to bring the valve back to
place again. The channelled edge of the valve will hold sufficient
water to make an air-tight joint, and as the water which flows through
the trap is always more or less dirty, and holds more or less sand in
suspension, the sediment which will be deposited will make an air-tight
joint, even after the water has evaporated.
When storm waters arc flowing rapidly in the catch basin of course
the valve will be held open by the volume of water, but as the flow
ceases the weight causes the valve to close, retaining a small quantity
of water in the channels around the edge of the valve. As this water
evaporates sediment will be .deposited, as before explained, sufficient to
close the joint against the passage of air or sewer gas.
The weight F is made of such a shape as to take the least room
possible in the catch basin, and so that by removing the grating or
cover the trap may be lifted out of the base ring in case it may become
necessary for repairs or any other purpose.
Having described the nature of the said Invention and the manner
of performing the same, I declare that what I claim as the Invention to
be protected by the herein-before in part recited Letters Patent is,―
1st. A stench trap composed of the cylindrical or conical frustrum A
provided with the valve E and weight F adjusted and operating as
described.
2nd. The combination of the valve E, weight F, and cylinder or
chute A, adjusted and operating as described to form a water joint in

page_text: wet weather, and a sediment joint in dry weather to resist the upward
flow or escape of foul air or gases from sewers.
3rd. With or without the cylinder A, valve E, and weight F, the base
ring C, cover G, and uprights H, when arranged substantially as and for
the purpose
described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Fifteenth day of June, in
the year of our Lord One thousand eight hundred and seventy-
six.