IMPROVEMENTS IN BELL TRAPS FOR DRAINS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Alfred Whyman White and John
Henry Evans at the Office of the Commissioners of Patents on the 14th July
1882.
ALFRED WHYMAN WHITE of Upper Holloway, and JOHN HENRY EVANS of
Wardour Street, both in the County of Middlesex, "IMPROVEMENTS IN BELL
TRAPS FOR DRAINS
"
It is well known that when the common bell trap applied to the drains of sinks,
gullies, and other similar purposes is left loose and at the command of servants or
other persons, they are very commonly removed altogether from the top of the
drain pipe when it is required to allow a large quantity of liquid to flow down such
pipes, and frequently through negligence they are not replaced immediately after
the passage of such liquid, the consequence being that if the drain pipe is not
properly trapped, objectionable effluvia, and dangerous gases have free passage
therefrom. The object of the present invention is to produce a self acting
apparatus whereby when an excessive quantity of liquid is required to pass away
quickly the bell trap is raised and held up while such excessive quantity is passing
and closes again automatically after it has passed. In order to effect this object I
employ the following arrangements The upper end of the drain pipe terminates
in the bottom of a small cistern or open topped box, the usual water seal being
formed around it in the said cistern. The bell which covers the end of the drain
pipe and dips into the water seal as usual is furnished with a stem projecting
upwards and passing through guides fixed in the cistern or in a separate moveable
frame which can be placed in and removed from the cistern at pleasure. The
cistern is divided transversely into two parts by a vertical partition which may be
fixed or moveable as preferred. The lower part of this partition is furnished with a
grating to keep back solid matter which it is desirable shall not pass down the
drain pipe. In the division of the cistern into which the drain pipe opens is the
bell trap, its water seal, and the aforesaid guides. In the other division is placed
a horizontal flap capable of turning on suitable centres. An arm extends back-
wards from this flap and is adapted to act on the stem of the bell trap so as to
raise or lower the same. If now an excessive quantity of liquid be poured into the
division containing the said flap, the weight of such liquid depresses the flap and

page_text: the arm thereon raises the bell trap so as to expose the full area of the drain pipe
for the passage of the liquid. So long as the excessive quantity of liquid is flowing
the flap remains depressed and the bell trap raised, but as soon as the excessive
flow has ceased the superior weight of the bell counterbalances that of the flap and
the bell falls into its water seal, returning the flap to its horizontal position. The 5
flap is by preference hinged independently on. its axis, so that it can be raised by
hand into the vertical positon without disturbing the bell trap to allow of the
removal from the lower part of the division in which the flap is placed, of any solid
matter retained therein by the aforesaid grating in the transverse partition. The
top of the cistern over the division containing the bell may be covered by a plate, .1
secured, so as to prevent tampering with the bell trap, or it may be adapted to slide
in grooves or to turn on a hinge or otherwise as may be preferred. The other
division containing the flap may be covered by a loose grating which can be
removed at pleasure, and if preferred a second moveable grating can be placed in
the said division above the Rap to prevent solid matter from passing to or clogging 1
the flap.
"
It will be understood that the cistern containing the above described arrange-
ments is let into the sink, so that its top comes level, or a little below the upper
surface thereof, and when applied as a gulley the cistern is sunk into the ground
until the top is level or a little below the bottom of the gutter and similarly for i
other applications.