Note: Descriptions are shown in the official language in which they were submitted.
-- 2128781
. . . ~
..
..
Title: DUAL FLUS~ CISTERN
. ,
TEC~NICAL FIELD ~ ;~
The present invention relates to a flu~hing
mechanism for a toilet cistern and more particularly to
a dual flush cistern.
BACRGRO~ND ART
A variety of sy~tems have beon used to provide a
mechanism for giving dual flu~hes of different volumas. - ;
These range from oomplicated mechanical linkage systems
to the provision of different chambers within the
cistern. The present invention seeks to providc a
simple system of providing a dual flush without the
problems associated with the ~nown systems.
DISC~OSURE OF INVENTION
According to the presont invention there is
provided a dual $1ush cistern having a flush sel~ction
and actuation mechanism mountod thorewith ha~ing a full
2~2878~
flush actuator and a partial flush actuator, a flushing
valve positioned in the base of the cistern, said
$1ushing valve having a stem able to be lifted to open
the flu~hing valve by a lifting mechanism of said flush
selection and actuation mechanism, a float housing
mounted to the cistern having a ba~e portion and wall
portions extending upwardly from the base portion and ~ :
housing a float connected to said stem, said housing ~ ;~
mounted relative to the cistern such that it i8 below
the normal water level when the cistern is full and
above the normal water level following a partial flush,
said housing having outlet means therein to enable water
to drain therefrom, said outlet means being controllable
to provide at lea~t first and second drainage rates from
said housing, said second drainage rate being faster
than first drainage rate, said outlet means responsive
to actuation of the partial flush actuator of the flu~h
selection and actuation mechanism to cause drainage from
said housing at said second rate and responsive to
actuation of the full flush actuator of the flush
selection and actuation mechani~m to cause drainage from
said housing at said first rate.
For preference, said outlet means comprises first
and second openings in said housing, the second opening
being selectively openable and closable by a control
means, said control mean~ being operative to open said
said second opening in response to actuation of the
212878~
- 3 -
partial flush actuator of the flush selection and
actuation mechanism. For preference, ~aid ~econd
opening pro~ides a faster drainage rate than the first
opening. Preferably, the control means comprises a
slidable gate po6itioned in said second opening and
responsive to operation of ~aid partial flush actuator
to open ~aid second opening and re~ponsi~e to said float
reaching the ba e of said float housing to clo~e said
second opening. Preferably said housing is an annular -
housing positioned around ~aid stem. For further
preference said float is annular and i~ positioned
around said stem. Preferably, the float housing is
adjustably mounted to ~aid cistern ~o that its vertical
position relative to the cistern can be adjusted. For
preference, the ~lidable gate is coupled to the partial
flush actuator by an adjustable linkage 80 that the
degree of oponing of the slidable gate in respon~e to
the operation of the partial flush actuator i~
adjustable.
BRIEF DESCRIPTION OF DRAWINGS
A preferred embodiment of the present in~ention
will now be de~cribed, by way of example only, with
reference to the accompanying drawings, in which:
Figure 1 i~ a ~ectional ~iew taken through the
centre of the float hou~ing of tho ci~ er~ according to
the invention;
212878:t
Figure 2a i8 a plan view of the float housing of
Figure l; ~ ~
Figure 2b is a under~ide view of the float hou~ing ~: :
of Figure l;
Figure 2c i~ a elevation view of the float hou~ing
of Figure l;
Figure 3a is a plan view of the float of Figure l;
Figure 3b i8 a sectional elevation view of the
float of Figure 1 taken on lines 3b-3b;
Figure 4a i8 an elevation view of the float housing
gate of Figure l;
Figure 4b is a underside view of the float hou~ing
gate of Figure l; and
Figure 4c is a side elevation view of the float
housing gate of Figure 1.
BEST MODE OF CARRYING OUT THE INVENTION
Referring to the drawing~, the dual flushing
mechanism according to this embodiment comprises a
cistern having a floor of substantially conventional
construction. The floor (not shown) is provided with an
outlet in substantially conventional fashion which is
able to be opened and closed by an annular seal 10 at
the lower end of a hollow stem 11 which in this
embodiment also act~ as an overflow tube. The seal 10
and the outlet (not shown) together constitute a flush ~.
valve 12 while the etem 11 constitutes an overflow tube
through which water can pass to the outlet should the
` 212878~
level of water in the ci6tern exceed the intended
maximum level.
As be~t seen in Figure 1, the ~tem 11 i6 provided -
with an annular float housing 13 which i~ supported in
cantilevered fashion by a connecting bracket 14 which
i8 fixed relative to the ci~tern. The float housing 13
sits around the stem 11 while allowing the stem to move
freely through its central opening 15. The float
housing 13 i~ adjustably attached to the connecting
bracket 14 by removable pins 16 which engage with a
series of vertically ~paced adjuætment holes 17 provided
along the length of the connecting bracket 14.
The float housing 13 ha~ a ba~e 18 and an An~ular
wall 19 extending upwardly ~rom the base to form the
housing. The base 18 is provided with the central
opening lS for the stem 11 to pass through. The annular
wall 19 is provided with an opening 20 which i8 openable
and closable by a vertically movable gate 21. The gate
is slidingly fitted to the opening 20 by mean~ of a pair
of channels or grooves 22, 22' extending adjacent the
vertical sides 23, 23' of the opening 20. The float
housing gate 21 i~ connected at its upper edge to a gate
lifter arm 24 by means of a longitudinal slongate slot
25 and pin 26 respectively provided in the lifter arm 24
and gate 21. This arrangement allows t~e gate 21 to
move upwardly relative to the lifter arm 24 while still
e~abling the lifter arm 24 to raise the gate 21 when the
~ '''`~'~'
^ - 212878~
lifter arm 24 moves upwardly relative to the gate 21.
The lifter arm 24 i~ adju~table in length 80 that the
degree of opening of the gate 21 may be varied.
The ~tem 11 i8 provided with a circumferentially
extending rib 27 towards its upper end which i8 engaged
by a lifting yoke 28 pivotally connected to a full flush
lifting arm 29.
An annular float 30 compri~es an upper side 31
having a ce~tral opening 32, an inner wall 33 extending
downwardly from the periphery of the opening 32 and an
outer wall 34 extending downwardly form the outer
periphery of the upper ~ide 31. The buoyant nature of
annular $10at 30 ia provided by air trapped in the space
between upper ~ide 31, inner wall 33 and outer wall 34.
Additionally or alternatively annular float 30 may be
Formed of a buoyant material such as an expanded
polymer. The stem 11 pa~se~ through the opening 32 and
the float 30 is fixed to the stem ll. The float 30 is
dimensioned to fit neatly within the float hou~ing 13
while still allowing for free vertical movement therein.
The float hou~ing gate 21 will now be de~cribed in
more detail with roference to Figure 4. The gate ~;
comprises a ba~e portion 40 a~d a vertieally extending
~ide portion 41. A~ best shown in Figure 4a, the base
portion 40 i8 provided with an e~larged section 42
through which extend~ a circular opening 43, which, in
u~o, ~lidingly accommodates the ~tem 11. The side ;
:` :
` 2~28781
portion 41, a6 best 6hown in Figures 4b and 4c, i~
pro~ided with a pair of ~ertically ~paced protru6ions 44
and 45 on opposite 6ide6 of the 6ide portion 41.
In use the system operate~ as ~ollows. Prior to
flushing the upward bias on stem 11 produced by float 30
i8 resisted by the downward bias on stem 11 produced by
water pre~ure on the upper face of flush val~e 12. For
a full flush, the full flush lifting arm 29 iB raised by
actuation of the full flush button (not sh~wn). This ~ -~
arm in turn raises the stem 11 by means of the yoke 28
engaging the rib 27. Raising of the ~tem 11 causes the
float 30 to be raised within the float housing 13 which
is initially full of water while simultaneously opening
flush ~al~e ~eal 10 causing the water to drain from the
cistern. As the water level drop~ within the cistern
the stem iB held in a raised positio~ by the float 30
which floats on the water held in the float hou~ing 13.
Water gradually escapes from the float housing 13 around
the opening 15 and the float 30 drops allowing the stem
11 to drop closing the flush val~e seal 10 by which time
a full flush as been co~pleted.
For a reduced or half flush, the gate lifter arm 24
is raised which raise~ the gate 21 which in turn opens
the opening 20 in the wall of the float housing 13. ~ -
When the gate i8 raised the protrusion 44 engages the
upper edge of the outer wall 19 of the float housing 13
holding the gate 21 in an open position. The baso ;~
21287~31
-- 8
portion 40 of the gate 21 engages with the inner wall 33
of the float 30 raising the float and the ~tem 11
causing the flush valve seal 11 to open. As the water
level in the cistern drops, water in the float housing
exitg ~uickly through the opening 20 allowing the float
30 to drop more ~uickly and clo~e the flush valve ~eal
11 before a full flush has been completed. As the float
30 drops, it~ neat fit within the housing 13 causes it
to hit protrusion 45 and knock the protrusion 44 from
the outer wall 19 of the housing 13 and causing the gate
21 to cloge thus resetting the gystem for the next flush.
The operation i~ adjustable by varying the amount
the sliding gate openg and thus the rate of digcharge of
water from the float housing and al~o by varying the
vertical position of the float housing within the
cistern.
It will be ~ppreciated by those skilled in the art
that further e~bodimentR of the invention are posgible
without departing from the spirit or ~cope of the
invention described and the invention i8 not limited to
the particular ~odiment described.
...; ' '. '~
