IMPROVEMENTS IN SEWER TRAPS
Year: 1885

page_text: We, HUGH STEVEN, of the firm of McDowall Steven and Company, Milton Iron
Works, Glasgow, in the County of Lanark, North Britain, Ironfounder, and
WILLIAM MORE, of the same place, Foreman Ironfounder, do hereby declare the
nature of our said invention for "IMPROVEMENTS IN SEWER TRAPS" and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :-
Our said Invention relates to sewer traps of the kind known as Lowe's and has
principally for its objects to make such traps more conveniently accessible for
inspection and cleaning and less liable to become choked, our Invention also
comprising other minor advantages.
A sewer trap as made with our improvements is shown on the accompanying
sheets of explanatory drawings, figure, 1, being a plan, and figures, 2, and 3, vertical
sections as at right angles to each other, whilst figures, 4, and 5, represent a lever
key used for opening and closing the trap.
:
The sewer trap consists of a rectangular box-like iron casting, A, made with two
internal partitions B, C, which form the trap or siphon part, one, B, of these
partitions dipping down from the top, and the other, C, extending from the bottom
to a height a little above the bottom of the partition, B. The outlet, D, into the
sewer is between one end of the box and the lower partition, C, the rest of the box
being formed with a closed bottom, E; whilst the internal space between the
higher partition, B, is covered by a hinged grating, F, through the openings in
which the sewage finds its way into the box. Heretofore a dry or baked rock-sand
core has been used for shaping the trap or siphon part and the internal surfaces of
the metal at that part have consequently been comparatively rough and liable to
become coated with matters deposited by the sewage. By our present Invention
however the entire sewer trap is moulded in green sand in order to obtain smoother
surfaces the pattern parts used for moulding the partitions B, C, being arranged to
slide or be withdrawn from their places after the mould has been partly formed.
Another improvement connected with the formation of the trap or siphon part
consists in placing the lower partition, C, with a slight inclination such as to make
the outlet, D, a little wider towards its lower part, an arrangement allowing
matters passing through the trap to get away more freely than with the ordinary
Lowe traps the outlets of which have generally been made slightly narrower at
their lower parts than at their upper parts.

page_text: By our Invention convenient access is given to the trap or siphon part, without
its being necessary to open up the roadway or pavement, by fitting a movable
cover, G, above that part, provision being made for securing this cover in a simple
and yet sufficient manner and for making it gas tight. This cover, G, fits into the
seat provided for it so as to be flush with the top of the box or casing and it rests
on an internal flange, H, the upper side of which is grooved to receive a slightly
projecting rib formed round the under edge of the cover, G. The groove of the
Hange, H, is filled with white lead and tallow or other suitable composition before
the cover, G, is put into its place and a gastight joint is thereby formed. When
closed the cover, G, is locked by means of a crossbar, I, riveted to the inner end of
a pin, J, which has cast on it a round head, K, made with a square socket, and
which is inserted through a hole formed for the purpose in the cover, the upper
part of the hole being enlarged to receive the head, K. The ends of the cross bar, I,
when turned engage under the flanges, H, and the parts where they engage are
made with a slight inclination as shown at, L, in figure, 3, so that there is a
wedging action when the cross bar, I, is turned to secure the cover. A lever
key, M, shown in figures 4 and 5 is provided for turning the cross bar, this instru-
ment being made with a square bit, N, to enter the socket of the pin head, K. The
wedge locking action is so secure that the locking part cannot be turned excepting
by means of an instrument like that shown in figures, 4, and 5, and such that
leverage can be applied in using it. For lifting the cover, G, out of its place a
recess, P, is cast in it, a pin being fixed across in casting, and the instrument, M, has
one, end, Q, shaped for being inserted under the pin in the recess, P.
Having now particularly described and ascertained the nature of our said
Invention and what manner the same is to be performed, we declare that what
we claim is
1 The improved combination of parts forming the complete sewer trap
substantially as herein before described.
2-The moulding the trap or siphon part in green sand by means of movable
pattern pieces combined with the making of the outlet wider at its lower part as
hereinbefore described.
3-The providing of the trap or siphon part with a cover arranged for being
secured and rendered gastight in the improved manner substantially as hereinbefore
described.
Dated this twin month day of March 100K