IMPROVEMENTS IN DRAIN TRAPS
Year: 1885

page_text: I SAMUEL COWAN of Fifty two Maxwell Street Dalbeattie in the Stewartry
of Kirkcudbright, Joiner, do hereby declare the nature of my invention for
"IMPROVEMENTS IN DRAIN TRAPS" to be as follows:-
The object of the Drain Trap is to be self cleansing. It is made of fireclay and
glazed. The length of inlet is eight inches or thereby and four inches or thereby
in diameter with a fall in the eight inches of not less than one inch and not more
than three and a half inches forming a circle in shape. This brings the water and
sewage directly and with force on to the water in the trap.
The main feature in the trap however is the contraction at the water line at the
entrance and so on till it passes under the seal of the trap. In a six inch trap for
example at the entrance water line it is of oval shape six by three and a half
inches then it goes in a slanting direction and about the same size till it passes
the water seal when it extends to six inches in diameter at the outlet and so on
in proportion according to the size of the trap. The drawn or water check to be
not less than two and a quarter and not more than two and a half inches. The
slight curve and angle at the outlet make a better connection with the drain pipes.
The fresh air inlet is made to six inches square at the top with or with out
a facet and a three inch diameter escape for foul air may be put in behind the seal
of the trap.
I claim my invention to be a self cleansing drain trap.
COMPLETE SPECIFICATION.
I, SAMUEL COWAN of 52 Maxwell Street Dalbeattie, in the Stewartry of
Kirkcudbright Joiner do hereby declare the nature of my invention for IMPROVE.
MENTS IN DRAIN TRAPS and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The object of the drain trap is to be self cleansing by discharges from water
closets & passing directly through the trap to the drain; the trap remaining
always nerfectly clean.

page_text: The trap
made of fireclay and glazed. The length of inlet (C) is nine inches
or thereby and the diameter at the entrance four inches or thereby with a fall
in the nine inches (curved in shape) of three and a half inches. This brings the
water and sewage directly, and with force, on the water in the trap.
The main feature in the trap however is the contraction at the water line (D)
which is continued till it passes under the seal of the trap (E). In a six inch trap
for example at the entrance water line it is of oval shape six inches by three and
a quarter inches continued in a slanting direction and of same size till it passes
the water seal when it extends to six inches in diameter at the outlet; and so on
in proportion according to the size of the trap. The drown or water check or seal
to be not less than two and a quarter inches and not more than two and half
inches The slight curve and angle at the outlet are to make a better connection
with the drain pipes.
To meet some cases where there is not much fall the traps may be made as N° 2
with a fall of one inch in the nine inches of inlet and may be made in the usual
way with the inlet the same size as the outlet.
The fresh air inlet (B) in a six inch trap is extended to seven inches continued
at that width to the ground level, and finished with a coping (A) made of stone
or concrete or fireclay checked for iron grating and constructed so that only five-
eighths of an inch is shown round the grating when in position.
A four inch diameter escape for foul air may be put in behind the seal of
the trap.
The traps will be made all sizes from four inches to nine inches.
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
1. The extension in diameter of the air inlet allows (1) a greater pressure of
fresh air to be admitted into the house drain (2) a better and safer and prettier
finish at the surface is made with the stone, fireclay or concrete coping and grating
and (3) easier access to the trap is obtained when necessary.
2. That (1) from the length of curved inlet which the water has to flow over,
whereby the water and sewage are changed in their direction but not in force of
flow and fall directly on the water in the trap (2) from the oval shaped contraction
at the water line continuing till it passes under the seal and (3) from the length
of the trap from the water seal to the outlet forming an easy gradient, the water
and sewage from closets are made to pass directly through the trap and along to
the drain thus making the trap a self cleansing one.
Dated this tenth day of July 1885.