Improvements in and relating to Lavatory Basins
Year: 1897

page_text: I, GEORGE CHISHOLM Junr of the Craigs, in the City and County of Stirling, North
Britain, Manufacturing Plumber, do hereby declare the nature of this invention to
be as follows:-
It relates to Lavatory Basins and has for its objects to adapt them for retaining
water in, or discharging it from them without the intervention of plug valves and to
prevent their contents overflowing.
In carrying out one modification of the invention a well is formed or attached
beneath the grate or water outlet of a lavatory basin and a syphon pipe is fitted
into its base and covered with a bell or domed cover; the syphon pipe is extended
downwards into a bend or trap. A rod or other device is fixed to the aforesaid bell
or dome and a handle for lifting it. If the trap is filled with water the basin can
then be filled suitably for lavatory purposes. An air lock is thus formed within the
bell or domed cover and the syphon pipe above the trap which serves effectually to
retain the aforesaid water in the basin. When the water almost fills the basin or
much exceeds the depth of water seal in the trap the air lock in the syphon is
overcome and the water flows away.
Another modification of the invention differs from the foregoing description in
respect of the water-waste pipe and trap fixed beneath the aforesaid well. In this
modification the waste pipe is not a continuation of the syphon pipe, as before
described, but is of larger diameter than the syphon pipe and the latter pipe projects
a little way into it below the base of the well.
In either modification, the rod for lifting the syphon bell is enclosed within a shaft
or tube formed upon the basin internally or otherwise and the basin, well, syphon,
trap and other parts of these devices are by preference detachable one from another
for purposes of examination, repair packing and transit.
Tonna 1907
Improvements in and relating to Lavatory Basins.
I, GEORGE CHISHOLM Junior of the Craigs, in the City and County of Stirling North
Britain Manufacturing Plumber do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement;

page_text: It relates to Lavatory Basins and has for its objects to adapt them for retaining
water therein or discharging it therefrom without the intervention of plug valves and
to prevent their contents overflowing.
The invention will be better understood if reference is made to the accompanying
drawings.
In carrying out one modification of the invention, as shewn in figure 1 of the
drawings, a well, a¹ is formed or attached beneath the grate or water outlet, a², of a
lavatory basin A and a pipe, a³ is fitted into its base and covered with a bell or
domed cover at; the pipe a³ is extended downwards into a bend or trap a³. A
rod a or other equivalent device is fixed to the aforesaid bell or dome having a knob
or handle a for lifting it. If the trap is filled with water, the basin A can then
be filled to the level marked as suitably for lavatory purposes. An air-lock is thus
formed under the bell or domed cover at and within the pipe a³ above the trap which
serves effectually to retain the aforesaid quantity of water in the basin A.
When the water almost fills the basin A or much exceeds in its depth that of the
water seal contained in the trap as the air in the parts a³, at is compressed until the
water rises above the level of a³ and commences to dribble away involuntarily.
The voluntary operation of the devices shewn in fig 1 is as follows:-
The trap a must first be sealed with water, therefore if the parts a, a, at are
raised as shewn by similar parts in fig 2 until the bell cover is level with the top
of the waste pipe water can be filled into the basin A and through the outlet holes
at a into the well a¹ and thereafter into the pipe 3 until the trap is full: the
parts a, a, a, must then be lowered into the position shewn in fig 1 when an
air-lock is formed within a3 and a sufficient to retain water in the basin A if it
does not rise above the level of the line as. If the water is allowed to continue
running into the basin A after it has reached the said level its increased head (and
consequent pressure) partially overcomes the air lock in and the water dribbles
over the lip of a³ and will continue thus to flow away as long as the water continues
to rise above the said level. The air-lock in a3 a4 is not totally and instantly
destroyed in this involuntary manner; it is only partially displaced from the lower
parts of the bell a; sufficiently displaced to allow the excess of water in A to escape
by the said dribbling into a³ and no more (unless it is long continued) as the air
confined in a³, at is not totally dispersed by the increased pressure but is forced
slightly forward into the waste pipe until such time as the water finds an escapement
over the lip of a³. If this dribbling is allowed to continue it gradually disperses the a
air-lock from a³, at and terminates by emptying the basin A with a syphonic flush.
This involuntary syphoning process is designed chiefly for safety and emergency
purposes and is dependent upon an excessive head of water in the basin A which it
is chiefly intended to relieve before overflowing can take place.
If the water in the basin A is not above its normal level for lavatory purposes as 4
indicated by the line as the devices a³, a cannot be made to operate as a syphon :
the water can then only be emptied from A by raising the bell and keeping it raised
as shewn in fig 2 until all above the lip of a3 has run off. If the bell at is lowered
into the well a¹ as shewn in fig 1 whilst this emptying process is going on it arrests
the flow at once.
By raising the bell a fig 1 for a short period much or little of the water below the
level of as can be allowed to flow off from the basin A bnt the flow ceases when the
bell is lowered again just as completely as if a metal plug was inserted in the mouth
of a³.
4
The devices a³, a combined with a5 are not designed to act as a voluntary but 5
involuntary syphon appliance; and only thus when the water in the basin A reaches
a level above the line as; or any other level which may be required for lavatory
purposes; it is then only for purposes of safety or emptying the well a¹.
The devices a³ to a can be made to operate as a syphon for flushing out the
well a¹ at any time when water is in the trap a5 and basin A if the said basin is 5
filled above the level marked a³.
Another modification of the invention as shewn in fig 2 of the drawings differs

page_text: somewhat from the foregoing one in the construction of the water waste pipe b³ and
the trap b' beneath. the aforesaid well. The general form and arrangement of the
parts constituting the flushing devices for the basin B shewn in fig 2 resemble in
themselves and in their connection with the basins, (with one or two variations),
those shewn in fig 1. The voluntary operation of the devices shewn in fig 2 is by
raising and lowering the handle 66, 67 after 65 has been filled with water and the
basin is in use.
In this modification the waste pipe and trap 65 is not a continuation of the pipe 63
similarly to a, as described and drawn in fig 1; but b' is of larger diameter than the
syphon pipe b and the latter projects a little-way into 65 below the base of the well 61
but not so low as the water level in 65: so that an air space always remains between the
water seal in 65 and the outlet end of the syphon pipe 63. The proportions of 63, 64 fig 2
are very different to those of u³, at fig 1 and are made designedly so in order to
produce very different results when in use. The air chamber in 63 is small compared
with that in 3 and the air chamber in 6 is-proportioned to that in 63. The
parts to a constitute a poor syphon, not very sensitive, whilst the parts b³ to 65
constitute a very sensitive one. Each set of devices, a³ to a and 63 to 6 are equally
competent to retain sufficient water in their respective basins for lavatory purposes;
each acts involuntarily as a syphon in the circumstances previously detailed under
the first named modification; that is, when water is allowed to flow continuously
into the basin: but 63 to 65 can at any time be made to syphon away the water
from B if the hell is momentarily raised and then lowered. If 64 fig 2 is
momentarily raised and then lowered whilst the water in B is at or near the level
marked 8, the rush of water into the small pipe 63 carries part of the air constituting
the air-lock in 63, 14 away with it and instantly converts 63 to 6 into a syphon
which rapidly and completely empties the basin B and the well b¹.
This instantaneous effect is due in part to the smallness of the bore in 63 which
has the effect of quickly forming the water as it flows over the lip of 63 into a
compact column within the pipe and thus commences the syphoning process.
The devices 1 to 6' are designed, when combined with a lavatory basin B, or such
like vessel, to act as a syphon both voluntarily and involuntarily in the manner
already described.
In figure 3 the flushing devices c¹ to c5 resemble those shewn in fig 2 except in
regard to their position. The outlet grate of the basin C, fig 3 is in the floor of the
pan and the well c¹ containing the syphon devices c³, c is fixed immediately
beneath it; the lifting rod es being projected upwards through the grate and within
a protecting tube or shaft c fixed within the basin.
The devices c¹ to c are designed to operate involuntarily and be operated
voluntarily in the same syphonic manner as those marked b¹ to ' fig 2.
In fig 4 the tube or shaft containing the bell rod d is placed somewhat differently
to those shewn in figs 1 to 3 being affixed to the wooden or other cover upon or
surrounding the basin D and the water flows from the basin into the well d' through
a branch pipe (10.
The parts d to d³ are constructed similarly to those marked a¹ to a' fig 1 and are
designed for operation in the same manner as the latter. A small relief hole d¹¹ is
pierced through the pipe d³ near the top edge for the purpose of draining away any
slight dribbling flow of water into D (such as often proceeds from a leaking tap)
before it rises above the lip of d³; if the leakage is too great to find vent at this
hole and overflows the lip of ³ it gradually carries away the air from the air-lock
in d³, d and terminates by emptying the vessel with a syphonic flush.
:
The devices d¹ to d cannot be made to syphon by lifting the bell d' if the depth
of water in the basin D does not exceed that of the water seal in d³ they can only
be made to act as a syphon by increasing the depth or head of water in D beyond
what that in d can sustain whereupon the air-lock in d³, d' gives way before the
pressure, dribbling commences and ends in a syphonic flush.
I am aware that, prior to my invention syphous with and without bell-shaped
covers, each adapted for containing an air lock and provided with an air expelling

page_text: device for voluntary undoing the said air-lock also having a trap for sealing with
water have been combined with lavatory basins which had a water holding capacity
(when filled too full) sufficient to overcome the said air lock involuntarily; and that
overhead cisterns have been made and fitted with bell covered syphons and traps for
only voluntarily flushing operations effected by the lifting up of the said bell: it will
therefore be understood that I do not claim such things as my invention.
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:
First, in a lavatory basin the combination therewith of the water holding flushing,
and trap devices all substantially as herein described with reference to figure 1 of
the drawings or any mere modification thereof for the purposes specified.
Second, in a lavatory basin the combination therewith of the water holding
flushing and trap devices all substantially as herein described with reference to
figure 2 of the drawings or any mere modification thereof for the purposes specified.
Third, in a lavatory basin the combination therewith of the water retaining,
flushing and trap devices all substantially as herein described with reference to
figure 3 of the drawings or any mere modification thereof for the purposes specified.
Fourth, in a lavatory basin or such like vessel the combination therewith of the
water retaining discharging and trap devices all substantially as herein described
with reference to figure 4 of the drawings or any mere modification thereof for the
purposes specified.
Fifth, in a lavatory basin or such like vessel the combination therewith of a bell
or equivalent device by the raising or lowering of which water can be released
from or retained in it all substantially as herein described with reference to figure 1
of the drawings or any mere modification thereof for the purposes specified.
Sixth, in a lavatory basin or such like vessel the combination therewith of a bell
or equivalent device by the raising and lowering of which the water can be
syphonically discharged from such vessel all substantially as herein described with
reference to figures 2 and 3 of the drawings or any mere modification thereof for
the purposes specified.