Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVEMENTS IN OR RELATING TO VALVES
The present invention relates generally to valves, in one
aspect particularly to valves which are immersed in the
fluid the flow of which the valves control, and in another
aspect particularly to valves for controlling the flow of
fluids through the valve. More particularly, the present
invention relates to valves for controlling the flow of
liquids, particularly water. Even more particularly, the
present invention relates to valves suitable for use in
cisterns for flushing toilet bowls and the like, such as
inlet valves for admitting water to the cistern, and
flushing valves, particularly dual flushing valves, located
in cisterns for controlling release of water from the
cistern. The present invention finds particular
application as the inlet valve and/or as the dual flush
cistern valve having two modes of operation in cisterns
located in buildings such as office blocks, hotels,
domestic houses or the like.
Although the present invention will be described with
particular reference to a cistern having a dual flush valve
and/or an inlet valve, it is to be noted that the present
invention is not restricted to such arrangements and uses
but rather the scope of the present invention is more
extensive so as to include other arrangements and uses of
the valve than those specifically described.
One problem with existing cistern inlet valves is that such
valves operate progressively between the two extreme
positions. Therefore, there is a variable flow of water
being admitted to the cistern which results in undesirable
noise such as that described as the "hissing" effect or
noise of water entering the cistern after the toilet bowl
has been flushed. This noise results from the inlet valve
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progressively approaching the fully closed position due to
the gradually restricting flow of water. In extreme cases
the unwanted noise can continue for lengthy periods of time
after the cistern has been flushed which can be annoying 5 and aggravating,
particularly in en suite situations at
night when the cistern is flushed which may awaken the
sleepers in the adjoining bedroom, or in multiple dwelling
buildings.
Another problem associated with currently used valves in
cisterns is that they are bulky and complex which results
in large amounts of space being occupied by the valve in
the cistern, particularly the operating mechanism of the
valves. This in turn requires that the cistern be of large
size. Large size cisterns reduce the places in which the
cistern may be located within a building, and reduce the
flexibility of stylists in designing the cistern and the
room in which the cistern is to be located.
Another problem associated with single flush valves is that
they waste water since they have no provision for reducing
the amount of water used during a flush even when it is not
required.
Another problem associated with existing cistern valves,
particularly dual flush cistern valves, is that they are
complex in operation and manufacture, having a large number
of separate components which interact together. Not only
are such arrangements expensive to make, but also over time
the components wear, particularly where adjacent components
are connected to each other, such as for example about a
pivotal joint, pin or similar, and/or where a sealing
element is provided. Wear in the operating or actuating
mechanism of the valve and/or in the sealing elements leads
to sloppiness or excessive clearances between components
which in turn results in leakages or other problems, such
as poor sealing of the inlets and outlets, which reduces
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the efficiency and effectiveness of the cistern and results
in all too frequent repairs being required. In many
instances, after extreme wear, valves more or less
continually drip water or allow water to leak from the
cistern, particularly into the toilet bowl, with
accompanying unwanted noise, including the annoying hissing
noise as the cistern is being continually replenished with
water as the valve oscillates between a partially opened
position and a closed position. in addition, continual
leaking of the cistern results in unsightly staining of the
toilet bowl.
Therefore, there is a need to provide a valve arrangement,
suitable for use in a cistern, such as a flushing valve,
particularly a dual flush cistern valve, which is efficient
in operation, made from a reduced number of components,
occupies a minimum of space, is silent or almost so in
operation, yet is effective in operation, and requires
little or no maintenance as well as being inexpensive to
build. The same requirements also apply to an inlet valve,
particularly an inlet valve which moves quickly and
silently between a fully closed and fully opened position
and does not cause or result in water hammer or the
production of unwanted noise.
According to a first aspect of the present invention, there
is provided a valve arrangement comprising at least one
movable valve member, said member being movable between an
open position and a closed position, and an actuating
member for causing operation of the valve member between
the open and closed positions, said actuating member being
mounted in such a manner that movement of the actuating
member in one direction is caused by a first force and
movement in a second direction is caused by a second force,
such that in one condition of operation of the valve
arrangement said first force predominates, whereas in a
second condition of operation of the valve arrangement said
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second force predominates.
Typically, the valve arrangement of the present invention
is an inlet valve or a flush valve, more typically a dual flush valve.
Typically, the valve is located in a cistern.
Typically, the first movable valve member is a cylindrical
tube. Typically, the tube is open at both ends. More
typically, the valve member is two open-ended cylindrical
tubes located co-linearly with each other. More typically,
the respective open ends of the two tubes are sealingly
interconnected together.
Typically, the movable valve member or the two or more
movable valve members move axially within the cistern.
Typically, with the flush valve the open position allows
egress of water to an outlet for discharge of the water.
More typically, there are two open positions wherein the
first open position corresponds to a full flush in which
the outlet is directly opened and a second position is a
half flush position in which the outlet is in fluid
communication with the or one of the cylindrical tubes,
thereby resulting in a half flush. More typically,.svhen
there is a single tube, said tube is arranged so that it
can adopt two different positions corresponding to two
different outlet positions depending on whether it is in
the full flush or half flush position. The single tube can
be located at two different heights, typically 30 cm above
the outlet in the full flush open position and typically
15 cm above the outlet in the half flush open position.
Typically, with the inlet valve the open position of this
valve allows water to be admitted to the cistern.
Typically, the actuating member for causing operation of
the valve member is a float or other member having a
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watertight chamber. Typically, the float is provided with
a locking edge. More typically, the float is provided with
a stop means for limiting the amount of pivotal movement of
the float during operation of the valve. More typically,
the actuating member is one, two, three or more floats.
Typically, the float is made from a plastics material or
similar.
Typically, the float is substantially triangular in
vertical section and substantially U-shaped in horizontal
section. Typically, the float is pivotally connected or
mounted within the valve arrangement.
Typically, the actuating member is connected or mounted off
centre or is connected at such a position which does not
correspond with its centre of gravity, so as to be
pivotable about its point of connection. More typically,
the float is pivotable under the influence of gravity and
is separately pivotable under the effect of buoyancy.
Typically, the first force causing movement of the
actuating member is the force of gravity. More typically,
the second force is a lift force provided by buoyancy of
the float.
Typically, the valve arrangement of the present invention
is suitable for use in a cistern. When the cistern is
empty, the force of gravity predominates to cause the float
to adopt a substantially vertical orientation or a more
vertical orientation. More typically, when the cistern is
full of water the force due to buoyancy of the float in the
water predominates to cause the float to adopt a vertically
inclined orientation. More typically, operation of the
valve is due to a combination of the forces of gravity and
buoyancy, more typically, said forces operating in sequence
to return the float to a position ready for further
operation.
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Typically, the cistern is provided with both a dual
flushing valve and an inlet valve which co-operate with
each other to effect operation of the cistern in use.
The present invention will now be described by way of
example with reference to the accompanying drawings in
which:
Figure 1 is a schematic side perspective view of
one form of one valve arrangement of the present invention
shown in isolation, said valve arrangement being a dual
flush valve shown in the fully closed position immediately
after flushing with the floats being vertical;
Figure 2 is a side elevational view of the form
of the valve arrangement of Figure 1 located in situ in the
half flush open position allowing a half flush of the
cistern;
Figure 3 is a vertical cross-sectional view of
the valve arrangement of Figure 2 in a fully closed
position thereby sealing the cistern with the floats in a
vertically inclined position in readiness for operation;
Figure 4 is a side elevational view of the valve
arrangement of Figure 2 in situ in the full flush open
position;
Figure 5 is a schematic side elevational view of
another form of a valve arrangement in accordance with the
present invention being an inlet valve in the open position
with the float arranged vertically;
Figure 6 is a side elevational view of one form
of the float member of the valve arrangement of Figure 5;
Figure 7 is a top plan view of the float of
Figure 6; and
Figure 8 is a side elevational view of a modified
form of the dual flush valve of the present invention
located in situ in a full flush position.
in Figures 1 to 4 there is shown one form of a flushing
valve arrangement being a dual flushing valve generally
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denoted as 2. Dual flushing valves are characterised as
having two outlets corresponding to two modes of flushing,
one being known as a half flush in which a lesser amount of
water is discharged to the toilet, and the other being
known as a full flush in which almost the entire content of
the cistern is discharged to the toilet bowl. Flushing
valve 2 comprises a main framework 4 which is securely
attached internally within a cistern by suitable means (not
shown). Framework 4 comprises a lower horizontal bracket 6
which can be securely fixed to the base or lower surface 7
of the cistern and which assists in securely fixing frame 4
in place. Bracket 6 is provided with a circular aperture
for receiving a lower portion of a flushing tube (to be
described in more detail later) which is located directly
above the outlet 9 of the cistern by a suitable fastening
means such as a threaded tube and nut arrangement 11.
Frame 4 further comprises a pair of horizontally spaced
apart vertically extending members 8 and an upper support
bracket 10 located at or towards the top of vertical
members 8 for interconnecting the members 8. A cap 13 is
provided at the top of bracket 10 between vertical members
8. Upper support bracket 10 is also provided with a
circular opening for receiving the upper end of an upper
flushing tube. A first movable valve member in the_form of
a hollow cylindrical tube 14 being open at either end and
acting as an upper flushing tube is received in the
circular opening of support bracket 10. Upper tube 14 is
free to move axially in bracket 10 between a fully closed
position and one of the open flushing positions. IIpper
tube 14 is provided with upper ring or collar 16 located
around its circumference intermediate its ends. Ring 16
may take any suitable profile and be made from any suitable
material. Upper tube 14 co-operatively interacts with
lower tube 18. The lower end of tube 14 is shown in
phantom in Figure 1 to reveal the internal details of the
sealing arrangement 17 between the lower end of upper tube
14 and the upper end of lower tube 18. The sealing
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arrangement 17 comprises a substantially V-shape seal or
tapered-edged seal 19 provided around the circumference of
the upper edge of lower tube 18 so that the lower edge of
upper tube 14 is received in the seal to seal the two tubes
together and prevent ingress of water internally into the
tubes during use when in the fully closed position and the
fully opened position.
The lower tube 18 acting as a second movable valve member
is arranged in end to end aligned relationship with upper
tube 14. A lower ring or collar 22 is provided
circumferentially around the outside of lower tube 18
intermediate the ends. The lower end of tube 18 is
provided with a seal arrangement 20. Seal arrangement 20
is additionally received within bracket 6 and is mounted
directly above the outlet 9 of the cistern as is lower tube
18. Seal arrangement 20 is provided with a substantially
V-shaped seal or tapered-wall seal 21 in which the lower
edge of lower tube 18 is received for sealing the cistern
against outflow of water in the fully closed position.
it is to be noted that the spacing of the upper ring 16
from the lower end of upper tube 14 is different to the
spacing of lower ring 22 from the lower end of lower_tube
18. Lower tube 18 is able to move axially between a fully
opened position and a fully closed position.
A central rod 26 is located axially within the aligned
upper and lower tubes 14, 18 and extends beyond the ends of
both tubes at either end. Rod 26 is maintained in place by
being received through centrally located apertures 27, 29
of spiders 28, 30 located at or towards the upper end of
upper tube 14 and the lower end of lower tube 18 =
respectively. Spiders 28, 30 may be formed integrally with
the tubes 14, 18 or may be made separately and assembled
with the tubes. Actuating lever 32 is connected at one end
to central rod 26 and at the other end to push rod 33 to
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effect movement of central rod to effect full flush of the
valve in which the valve is in the fully opened position.
The other end of push rod 33 is connected to full flush
button or similar (not shown) provided on the cistern.
Actuating lever 36 is connected at one end to the top of
spider 28 and at the other end to push rod 37 to effect
movement of upper tube 14 to effect half flush of the valve
in which the valve is only half opened by tubes 14 and 18
being separated from each other. The other end of push rod
37 is connected to half flush button (not shown) or similar
provided at a convenient remote location on the cistern.
An upper float 40 is pivotally connected to frame 4 at or
towards the upper end of vertical member 8 by means of a
pivot pin 42 or similar. A lower float 44 is pivotally
connected to framework 4 at a position intermediate the
ends of frame member 8 but located more towards the lower
end by a pivot pin 46 or similar. IIpper and lower floats
40, 44 are free to pivot between two different operating
positions, one position beiaQ the fully closed position
adopted when the cistern is full of water and the other
position beinQ for locking either tube 14 or tube 18 in the
open position.
Floats 40, 44 are airtight so as to define a closed chamber
and are pivoted off centre so that the pivot point does not
coincide with the centre of gravity or the centre of lift.
In this msnner floats 40, 44 are free to pivot to adopt a
more vertical position or substantially vertical position
under the influence of gravity when the cistern is empty
and are free to pivot to adopt an inclined position when
the cistern is full of water or in either of the flush
positions.
The normal in use position of the floats 40, 44 when the
cistern is full of water is such that they adopt an
inclined position with respect to frame member 8 as shown
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in Figures 2 to 4 due to the buoyancy of the air filled
floats. In operation, the floats 40, 44 move to a less
angularly inclined position such as a more vertical
position as shown in Figure 1 to allow the valve members
14, 18 to return to their closed positions depending on the
mode of flushing the cistern. Float 40 is provided with a
locking edge 48 along the upper inboard edge facing upper
tube 14 for co-operatively engaging upper ring 16 in use,
and a shoulder 49 extending obliquely along one side edge
for engaging with the edge of frame member 8 to limit the
movement of float 40. Float 44 is provided with a similar
locking edge 50 along the upper inboard edge facing lower
tube 18 for co-operatively engaging lower ring 22 in use,
and a shoulder 51 extending obliquely along one or both
opposite sides for engaging with the edge of frame member 8
to limit the pivotal movement of float 44 in the anti-
clockwise direction.
The operation of the valve arrangement of the present
invention will now be described, starting with the half
flush operation. In operation of a half flush of flushing
valve 2 of the present invention, the cistern is full of
water up to the level shown in Figures 2 to 4, which level
is close to the top of upper tube 14. It is to be noted
that the level of water is below the level of the upper
edge of the open topped inlet tube 14 and is about the
level of upper bracket 10 of frame 4. When the cistern is
full floats 40, 44 adopt an angularly inclined position as
shown in Figures 2 to 4 with the respective actuating
corners 48, 50 of floats 40, 44 respectively in contact
with the side wall of the two inlet tubes 14, 18,
particularly as shown in Figure 3. In this condition the
position adopted by valve 2 in Figure 3, which is the fully
closed position, is such that upper tube 14 is sealed to
lower tube 18 which is sealed to outlet 9 thus containing
water in the cistern and preventing any discharge of water
from the cistern to the toilet. This is the normal
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position of the cistern in a state where it is ready for
operation. Water is admitted to the cistern through a
separate inlet valve, details of which will be described
below.
, 5 When it is desired to half flush the cistern, the half
flush button on the cistern is pushed thereby actuating
push rod 37 and lever 36 to lift tube 14 out of sealing
engagement with tube 18 and breaking seal 17 to separate
the lower end of tube 14 from the upper end of tube 18
since tube 18 remains in place in sealing engagement with
seal 20. By this operation, tube 14 is lifted sufficiently
to allow ring 16 to pass locking edge 48 of float 40 by
float 40 pivoting very slightly in the clockwise direction
and returning to its former position so that edge 48 rests
against and under supporting ring 16 to lock tube 14 in
spaced apart relationship from tube 18 as shown in Figure
2. in this position water is free to flow through the gap
between the two tubes as shown by arrow A of Figure 2. It
is to be noted that tube 18 is undisturbed in this
operation and remains sealingly engaged to the outlet 9 of
the cistern.
As the level of the water drops to below float 40 which is
also to a level corresponding to about the top of tube 18,
the lift provided to float 40 due to buoyancy is no longer
acting. Owing to float 40 being pivoted off centre, float
40 pivots of its own accord under the influence of gravity
in an anti-clockwise direction thus moving the edge 48 and
releasing ring 16 from being locked by edge 48 to adopt a
position as shown in Figure 1. It is to be noted that
float 40 is prevented from pivoting too far by edge 49
contacting frame S. As-ring 16 is released tube 14 falls
under gravity to re-establish sealing contact with tube 18
and form a seal with seal 19. Water is then admitted to
the cistern by a suitable inlet valve (to be described in
more detail later) whereupon the level of water in the
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cistern rises to the former level. The rising water level
provides lift to float 40 thereby allowing float 40 to
pivot in a clockwise direction as shown in arrow B of
Figure 2 to adopt an angularly inclined position in
preparedness for the next half flush or full flush. It is
to be noted that when the cistern is empty float 40 is
vertical whereas when the cistern is full float 40 is
vertically inclined.
in operation of the full flush mode of the flushing valve 2
of the present invention, when the cistern is full the
water level is as described previously. The full flush
button of the cistern is pushed which moves push rod 33
which in turn activates lever 32 to lift central rod 26
which is connected to lower tube 18 by spider 30 and
aperture 29 thus lifting tube 18 out of sealing engagement
with seal 20 by lifting tube 18 from seal 21 to expose a
gap therebetween through which water may flow to outlet 9
as shown by arrow C of Figure 4. Tube 18 is lifted
sufficiently for ring 22 to clear edge 50 of float 44 to
allow edge 50 to rest against and under ring 22 to support
tube 18 in the fully open position and maintain the valve
in this position until the level of the water in the
cistern falls below the lower edge of float 44 which is
about the level of the outlet 9. It is to be noted that as
tube 18 is lifted so also is tube 14 so that the seal
between tubes 14 and 18 is maintained at all times during
the full flush mode of operation and the only outlet for
the water is through the bottom of the cistern. It is
noted that during this operation float 40 also pivots.
However there is no effect on operation of the device since
in this mode of operation float 40 does not contact ring 16
due to the different spacings of ring 22 from float 44 and
ring 16 from float 40. Further, it is to be noted that the
positions of rings 16, 22 are such that tubes 14, 18 will
be retained in one of two positions - either the full flush
position, or the half flush position. It is not possible
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for the locking edges of both floats to lock both tubes
simultaneously.
As float member 44 is mounted similarly to the mounting of
float 40, float 44 pivots anti-clockwise in accordance with
the force of gravity to release ring 22 and allow tube 18
to gravitationally fall thus resealing outlet 9. An inlet
valve then operates to admit water into the cistern so that
the level rises past float 44 and then past float 40
whereupon each float in turn pivots clockwise to assume
their former positions respectively with edge 50 resting
against tube 18 and edge 48 resting against tube 14 but at
locations above the respective positions of rings 16, 22.
Another form of the valve arrangement of the present
invention will now be described, being an inlet valve 60
which is located inside the cistern (not shown). The base
or lower surface 62 of the cistern is provided with an
aperture through which a stand pipe 64 is received and
sealed thereto with a conventional sealing filling. Stand
pipe 64 is connected to the normal pressurised water supply
and supplies water internally into the cistern. Supply of
the water to the cistern is controlled by operation of
inlet valve 60.
Valve 60 is located at the top of stand pipe 64 immediately
above water entry orifice 66 and delivery pipe 68 provided
with a spout (not shown) or similar nozzle for dispersing
the energy of the incoming water thus resulting in silent
operation of the valve. Valve 60 comprises a float 70
which is generally right angle triangular in vertical cross
section and generally U-shaped in horizontal section as
shown in Figures 6 and 7. Float 70 is arranged so that
stand pipe 64 is located in the cut-out of the "II" and is
pivotally connected to the stand pipe with one of the sides
of the triangular float being substantially vertical,
another side being substantially horizontal, said sides
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being arranged substantially perpendicular to each other,
and the third oblique side being angularly inclined to the
other two sides. However, it is to be noted that the
precise shape of the float can be varied. In the normal
position, which is to say the prepared-for-operation
position when the cistern is full, the float is angularly
inclined to the stand pipe which is a position in which the
float is pivoted in an anti-clockwise direction from that
shown in Figure 5. Float 70 is provided with a yoke 72 at
a position along its upper side in use towards the apex of
the horizontal side with the oblique side. An actuating
lever 74 or lever 76 or push rod or similar force or motion
transmitting device or linkage is connected to the yoke at
one end and is provided with or connected to a cam 78 at
the other end. The link and cam arrangement is such to
allow the cam 78 to bear upon the upper end of plunger 80
located in a suitable housing 82 forming a plunger valve.
It is to be noted that a single lever provided with a
roller wheel at each end can be used in place of the pair
of levers 74, 76 and cam 78. in this embodiment, one of
the roller wheels acts directly on plunger 80 of the
plunger valve.
Two "0" rings 84, 86 are provided between plunger 80 and
housing 82 to seal the housing and prevent water from
escaping from the housing. A pad 88 is provided at the
lower end in use of plunger 80 for selectively closing and
opening water entry orifice 66 and thus regulating the flow
of water from stand pipe 64 to delivery pipe 68 through
water entry orifice 66. Housing 82 is provided with an
adjustable threaded cap 90 for adjusting the amount of
travel of plunger 80 so that a gap exists between the top
of plunger 80 and cam 78 while the float 70 is in its
vertical position allowing water into the cistern, yet
allows sealing contact between pad 88 and orifice 66 when
the valve is in the closed position. One modification of
the plunger valve is to provide the valve with a mechanical
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lock so that excessive water pressure will not force the
valve to inadvertently open or leak.
In operation of this form of the inlet valve 60, when the
cistern is empty float 70 is in the vertical position or in
a substantially vertical position as shown in Figure 5 so
that cam 78 is spaced apart from plunger 80 thus releasing
pad 88 from orifice 66 allowing water to flow from stand
pipe 64 through orifice 66 to delivery pipe 68 into the
cistern. As the level of water in the cistern increases to
around where float 70 is located, the lift applied to float
70 overcomes the effect of gravity on float 70 so that
float 70 rotates in an anti-clockwise direction as shown by
arrow E of Figure 5. As the level of water rises the
centre of lift or pressure moves from left to right, as
shown in Figure 5, of a position immediately below the
pivot point causing the float to rotate in an anti-
clockwise direction with increasing force. Movement of
float 70 causes yoke 72 to raise along with levers 74, 76
which causes lever 76 to pivot about pivot 77 so that cam
78 comes into contact with plunger 80. As cam 78 moves
further around plunger 80 is pushed further into housing 82
so that pad 88 is forced into contact with the end of
orifice 66 to stop the flow of water into the cistern. As
pivoting movement of float 70 is almost instantaneous the
closing of orifice 66 is instantaneous thereby eliminating
the "hissing noise as the valve is progressively closed in
prior art cisterns.
in one embodiment the roller wheels are used to eliminate
any unwanted friction.
In Figure 8 there is shown a modified form of the dual
flush valve of Figures 1 to 4 which modified valve is
similar to the valve of Figures 1 to 4 except that a single
tube 100 replaces upper tube 14 and lower tube 18.
Accordingly, the same reference numerals will be used for
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corresponding features in Figure 8 as are present in
Figures 1 to 4. Additionally, as tube 100 is a single tube
extending from bracket 6 to bracket 10 and axially movable
therebetween in use there is no sealing arrangement 17 or
seal 19. Tube 100 operates in the same way as tubes 14 and
18 in that tube 100 may be lifted a small amount, such as
for example 15 mm from seal 20 to adopt a half flush
position or a larger amount, such as for example about 30
mm, to adopt a full flush position.
In operation of this modified valve arrangement the cistern
is full of water as indicated by the water level in Figure
8. When a half flush is required, tube 100 is lifted by
operation of push rod 37 and lever 36 so that ring 16 is
locked by edge 48. in this position the lower end of tube
100 is spaced about 15 mm from outlet 9 so that water flows
through the outlet at a reduced rate until the level of the
water reaches to just below float 40 whereupon float 40
pivots anti-clockwise to disengage edge 48 from ring 16 and
allow tube 100 to gravitationally fall to re-establish seal
20 and thus the valve adopts a fully closed position after
delivering a half flush. It is to be noted that as ring 22
is located relatively further away from edge 50 than ring
16 is from edge 48, edge 50 does not lock against ring 22
but rather ring 22 is located below edge 50 and therefore
float 44 is inoperative in the half flush mode. After the
half flush mode, inlet valve 60 operates to fill the
cistern again and float 40 is caused to adopt its "ready"
position which is as shown in Figure 8.
When it is desired to full flush the cistern, push rod 33
and lever 32 are operated to lift tube 100 a greater amount
so that lock edge 50 engages against ring 22 to lock tube
100 about 30 mm above outlet 9. In this position
corresponding to the full flush, water flows through outlet
9 at a greater rate. it is to be noted that in the full
flush position ring 16 is located above the position of
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lock edge 48 and hence float 40 is inoperative in the full
flush position. As the water level lowers in the cistern
to just below float 40, float 40 pivots anti-clockwise
under the influence of gravity but as ring 16 is located
above edge 48 there is no effect produced by the movement
of float 40 and tube 100 is still maintained in the full
flush open position by edge 50 against ring 22. The water
level continues to fall until just below float 44 which
then pivots anti-clockwise to release ring 22 and allow
tube 100 to fall gravitationally into seal 20 to re-
establish the seal. Inlet valve 70 then operates to fill
the cistern and both floats 44 and 40 pivot clockwise to
the "ready" position in turn under the effect of buoyancy
as the water level rises past each in turn.
Advantages of the inlet valve of the present invention are
that the inlet valve is unique in construction in that it
is either in the fully open position or in the fully closed
position, there being no delayed progressive movement
between the two extreme positions, but rather there is only
instantaneous operation between the two positions. The
inlet valve has no intermediate stops or delays. This
advantage has been achieved by designing a hydrodynamic
float which will remain in the fully open position, that is
in which the float extends vertically downwards as
disclosed in Figure 5, until the rising water in the
cistern reaches a predetermined level when the valve will
move freely and effortlessly without sound to the fully
closed position thereby stopping the flow of water into the
cistern. Additionally, even though the valve moves quickly
between the open and closed positions, there is no water
hammer produced.
The float moves a lever so designed that it produces, by a
compounded mechanical advantage, considerable force on the
opening of orifice 66.
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When the valve is in the open position water enters via the
delivery pipe from where it is sprayed onto the cistern
wall at a preset angle and at a constant rate. The nozzle
through which the water is sprayed is designed so that the
energy of the incoming water is absorbed by the side wall
of the cistern resulting in no noise.
As the flow rate of water being admitted to the cistern
throughout the filling period is constant, it is possible
to eliminate the irritating hissing noises associated with
conventional cisterns which employ a progressively.closing
valve.
Another advantage of the present invention is that the
"horse-shoe" horizontal section of the float permits a
wrap-around effect of the vertical stand pipe, thus
reducing the space required for the components of the valve
and for operation.
It is to be noted that the inlet valve of the present
invention and the dual flushing valve may be arranged
together within the same cistern so that both valves
operate in combination with each other.
A further advantage of the dual flushing valve of the
present invention, particularly the valve of Figure 8, is
that a reduced number of components are employed and
further there is only a single seal required, which
contributes to the low cost of manufacture and the
reliability of the valve arrangement.
The described arrangement has been advanced by explanation
and many modifications may be made without departing from
the spirit and scope of the invention which includes every
novel feature and novel combination of features
hereindisclosed.
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Those skilled in the art will appreciate that the invention
described herein is susceptible to variations and
modifications other than those specifically described. it
is understood that the invention includes all such
variations and modifications which fall within the spirit
and scope.
