FIELD OF THE INVENTION
[0001] The present invention relates to a spring loaded container for achieving a flush
of a toilet bowl. The container comprises a main body, a piston reciprocally arranged
in said main body and being loaded by a spring such that the piston will exert a force
on liquid housed within the main body. The spring loaded container further comprises
an inlet and an outlet connected to the toilet bowl.
PRIOR ART
[0002] In the art of water closets, it has been a long felt need to make smaller and smaller
flush tanks, and to provide these flush tanks lower and lower. In the early part of
the nineteen hundreds, it was not unusual to provide the flush tank, or cistern, close
to the ceiling of the bathroom. Usually, a flush was effected by pulling a chain or
the like, the chain being connected to a flush outlet in the ceiling mounted flush
tank. Also, the flush volume of the ceiling mounted flush tanks tended to be comparatively
large.
[0003] Since the 1960s, most flush tanks have been mounted in a wall to which the toilet
bowl is fastened, or simply as an integral part of a bowl/flush tank assembly, wherein
the flush tank has served as a back rest for a user sitting on the toilet bowl.
[0004] Now, there is a trend that toilet designers strive to omit the flush tank being mounted
above the toilet bowl and serving as a back rest. Instead, the designers want to use
the space available under the bowl for housing the flush tank. However, this space
is situated below the flush level (which usually corresponds to the height of a rim
of the toilet bowl), which means the flush water must be propelled up to the flush
level.
[0005] One way of achieving this propulsion of water up to the flush level is to use a pressurized
vessel, e.g. a vessel resembling an expansion tank, i.e. a vessel being provided with
a pre-pressurized bladder containing a gaseous medium.
[0006] However, one drawback with this type of pressurized vessel is that they pose a danger
for a user of the toilet. A significant amount of energy is stored in the bladder,
and this energy can be released in an explosion like manner should the expansion tank
break.
[0007] In another embodiment of the prior art, the flush water is loaded into a spring loaded
container, wherein a piston moves along a central axis and compresses a spring when
the container is filled with pressurized flush water. During emptying of the container,
the energy stored in the spring is released and transferred to the flush water.
[0008] In all prior art systems comprising an energy storing spring, the outlet from the
container is closed until it is time to empty the container. This means that the flush
water in the container is pressurized by the spring at all times, which in turn stresses
all gaskets necessary to seal between e.g. the piston and the container walls. Also,
should there be any leakage of pressurized flush water from the pressurized container,
this might seriously compromise the function of the spring loaded container.
SUMMARY OF THE INVENTION
[0009] The present invention solves this and other problems by a spring loaded container
including a holding means designed to hold a piston in a position corresponding to
a maximum volume of liquid being housed within the main body.
[0010] In order to achieve a flush containing more water than may be housed within the spring
loaded container, the outlet may be connected to an ejector designed to move liquid
from a cistern to the toilet bowl to be flushed.
[0011] In order to avoid squeezing of the piston in the main body, the holding means may
be arranged in a central position of the piston.
[0012] The invention also relates to a toilet having a flush tank including a spring loaded
container according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the following, the invention will be described with reference to the appended
drawings, wherein:
Fig. 1 is a sectioned side view of a first embodiment of the present invention;
Fig. 2 is a sectioned side view of the embodiment of fig. 1, seen from another side;
Fig. 3 is a view similar to the view of Fig. 2 showing the same embodiment in another
mode;
Fig. 4 is a side view showing a second embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0014] In Figs. 1-3, a spring loaded container 100 according to a first embodiment of the
present invention is shown. The spring loaded container comprises a cylindrical body
110 having a smooth inner surface such that a piston-like member 120 may perform a
reciprocating motion therein. Gaskets 130 are arranged to reduce leakage in the piston/cylindrical
body interface. A spring 140 urges the piston in a downward direction, i.e. such that
a volume delimited by the piston 120, the cylindrical body 110 and an outlet 150 from
the cylindrical body will become as small as possible.
[0015] The spring 140 is trapped between the piston 120 and a cup-shaped lid 160 which comprises
a cup shaped portion 170 and a bottom portion 180. The cup-shaped lid 160 is provided
such that its cup-shaped portion 170 and the cylindrical body 110 delimit a space
for the spring 140. The bottom portion 180 is provided with an opening 190, through
which a holding means 200 attached to the piston 120 projects when the piston is in
an upper position.
[0016] Moreover, an inlet 210 for tap water and an outlet 220 for surplus tap water are
arranged to allow for filling and evacuating of surplus water into and from the container.
In order to seal the container, a one-way lid 230 covers the opening 150. The one-way
lid 230 allows a fluid flow into the container, but blocks fluid flow in the other
direction. Curiously, however, there will never be a flow in the "allowed" direction,
only in the disallowed directions, such as will be described later.
[0017] With reference to fig. 2, the same embodiment as in Fig. 1 is shown, however in another
view. Except for the components disclosed above, Fig. 2 shows that the arm 240 is
hinged on a hinge 250, such that a hook 260 locks the holding means 200 when the arm
240 is in an upright position. By moving an upper portion of the arm 240 towards the
left in fig. 2, the hook will release from the engagement to the holding means 200.
[0018] Also, in fig. 2, the one way valve 230 is shown in an open position, and the outlet
150 is open to a nozzle of an ejector 270. However, the outlet 150 may also be directly
connected to an inlet of a WC bowl, i.e. without an intermediate ejector, e.g. via
a flushing pipe or similar. In such embodiment, flushing will be fully accomplished
by the water within the container.
[0019] In Fig. 4, another embodiment of the invention is shown. In this embodiment, the
piston is hold in its upper position by a lever 300, one end of which extending through
a wall of the cylindrical body, hence blocking the piston from travelling to a lower
position.
[0020] Below, an intended function of the previously described spring loaded container will
be disclosed. In the example below, the spring loaded container is situated in a flush
water tank and intended to power an ejector pump to effect a flush, but other uses
may also be considered, and lies within the scope of the present invention.
[0021] In a starting position, the piston 120 will be in a position wherein the spring 140
is unloaded, i.e. the piston 120 will be very close to the outlet 150. Also, the piston
will urge the one-way lid 230 into a closed position.
[0022] In order to charge the container with a load of pressurized water, pressurized tap
water is let in from the tap water grid. The pressure of the tap water will move the
piston 120 upwards, and the pressure exerted by the spring on the water will secure
that the one-way lid will remain closed, hence blocking flow of water out from the
container.
[0023] The piston will continue upwards until the holding means 200 engages the hook 260.
A chamfered surface of the holding means 200 will press the hook away from the holding
means, such that the hook 260 will be pressed to the right in fig. 2, and thereafter
engage the holding means.
[0024] The piston will continue slightly past the position wherein the hook 260 has engaged
the holding means 200. There, the piston will pass the outlet 220, and hence open
this outlet for communication between a space external of the container. As a result,
tap water flowing in through the inlet 210 after the piston has reached a position
wherein the outlet 220 is open will not move the piston; rather it will reject water
out from the outlet.
[0025] As mentioned above, the spring loaded container is suitably situated within a cistern;
this means that the water level in this cistern will rise due to water being expelled
out from the outlet 220 once the spring loaded container is full. When the water in
the cistern has reached a specific, predetermined level, the tap water is shut off.
The shutting off of the tap water supply will cause the piston to move downwards to
a position where the entire spring load is carried by the holding means 200 and the
hook 260. This means that the spring no longer will exert any pressure on the water
situated in the container.
[0026] Due to the fact that there is water present in the cistern in which the container
is placed, there will be pressure acting on the one-way lid 230, a pressure counteracting
the pressure in the container 100. This pressure will open the one-way lid 230. This
intended opening of the one-way lid 230 may be facilitated by spring loading the membrane
of the valve, or by providing it with a floatation aid.
[0027] As implied earlier, the invention has got its greatest benefits in the cases where
a flush water cistern is located on a lower level than a rim of a toilet bowl to be
flushed, and below, it will be explained how the spring loaded tank according to the
invention may be used for lifting water from a cistern located under the toilet rim.
[0028] In order to initiate a flush of the toilet, the arm 240 is brought towards the left
in Fig. 2. This movement will release the hook 260 from its engagement with the holding
means 260. Immediately after the engagement between the hook 260 and the holding means
200 has been terminated, the piston will start moving downwards, hence increasing
the pressure in the water in the container 100. In Fig. 3, the position of the piston
shortly after the hook has been released from the holding means and the piston has
commenced its journey downwards is shown. In this context, it should be noted that
water is an incompressible fluid, meaning that the piston's movement may be very limited,
while the pressure increase may be very significant.
[0029] The pressurized water will start flowing out through the open outlet valve 230 and
continue to the ejector pump 270, hence energizing this pump to start pumping the
water in the cistern towards the rim of the toilet bowl. It should be noted that the
combination of the opening angle of the one-way lid, the flow of water and the spring/floatation
device of the membrane of the one-way lid is such that the one-way lid will not close
due to the reverse flow through the one-way lid. Instead, the piston, powered by the
spring 140, will expel the water in the container through the one-way lid 230 and
power the ejector pump 270.
[0030] Once the piston has emptied the cylindrical body from liquid, it will engage the
one-way lid such that it will close, hence allowing the spring loaded container to
be refilled with water.
[0031] The function of ejector pumps is well known by persons skilled in the art of fluid
engineering, but some basic design criteria and description of their function will
nevertheless be given below:
An ejector pump uses a small flow of high pressure, high velocity liquid to cause
a large flow of low velocity, low pressure liquid. In the present case, the spring
loaded container provides for the small flow of high pressure, high velocity fluid,
whereas the contents of the cistern mixed with the high pressure, high velocity liquid
from the spring loaded container will constitute the low velocity, low pressure liquid.
[0032] The low pressure, low velocity liquid will raise to the level of a rim of the toilet
bowl, and effect a flush in the normal manner.
[0033] In one embodiment of the invention, two cisterns, two spring loaded containers and
two ejector pumps are used to enable dual flush, a feature mandatory in several countries.
A dual flush function is basically the ability for the user to choose between a "large
flush" and a "small flush". Usually, a "small flush" corresponds to a flush volume
between 2 and 4 litres, which is sufficient to flush down liquid leavings, whereas
a "large" flush corresponds to a flush volume of 4 to 8 litres, which is sufficient
to flush down both excrement and paper tissues used to wipe the user of the toilet.
[0034] The dual flush could be effected in several ways: In a first embodiment of a dual
flush toilet utilizing the spring loaded container according to the invention, two
cisterns and corresponding spring loaded containers of various volume are arranged
in the toilet, wherein the volume of one of the cisterns and its corresponding spring
loaded container corresponds to a large flush and the volume of the other cistern
and its corresponding spring loaded container corresponds to a small flush.
[0035] Hence, if a large volume flush is desired, the arm 240 of the spring loaded container
of the cistern having a volume corresponding to a large flush is maneuvered such that
the hook 260 releases the holding means 200. As a result of this, the piston 120 will
expel the water housed in the container to the ejector pump, which then will be powered
to raise the water of the cistern to a level wherein a flush is executed.
[0036] A small flush is done in the same way, but for a small flush, the arm 240 of the
spring loaded container of the cistern having a volume corresponding to a small flush
is maneuvered.
[0037] In another embodiment of dual flush according to the invention, there is provided
two cistern/spring loaded container assemblies, wherein a first of the assemblies
has a volume corresponding to a small flush, and the second of the assemblies has
a volume such that the combined volume of the first and second assemblies corresponds
to a large flush.
[0038] Hence, in order to achieve a large flush in a dual flush arrangement according to
this embodiment, both arms of the spring loaded containers are actuated simultaneously,
such that the pistons of both spring loaded assemblies will energize their corresponding
ejector pumps to empty their corresponding cisterns, hence achieving a large flush.
[0039] For all of the above embodiments, it is necessary to refill the spring loaded container
and the cistern with flush water. As mentioned above, the refill is performed by letting
in tap water through the inlet 210. When the spring loaded container is filled, the
tap water will escape through the outlet 220. In the dual flush solutions, the outlet
of a first spring loaded container is connected to the inlet of a second spring loaded
container, the outlet of which being connected to fill the cisterns corresponding
to the spring loaded containers. In this context, it could be worth mentioning that
the cisterns might be in fluid communication with one another in an upper region or
a lower region, or both. If the cisterns are in communication with one another in
an upper region, there is no risk that more water than necessary is ejected to flush
the toilet by the ejector pump.
[0040] The tap water supply is shut off in the "normal manner", i.e. when the water level
in the cistern has reached a certain level.
[0041] In still another embodiment of the invention, the outlet 150 is connected directly
to toilet bowl, such that the toilet bowl is flushed directly and solely by water
ejected from the spring loaded container.
[0042] It is also possible to achieve a dual flush function by arresting the piston before
it has reached its end position. In the embodiment of Figs. 1-3, this may be achieved
e.g. by increasing the length of the holding means 200, such that it may be possible
to engage the hook and the holding means as the piston has travelled about half the
way towards its end position. In this way, it is possible to achieve a large flush
by allowing the piston to travel all the way down to the one-way lid 270, and a small
flush by halting the piston by engaging the holding means and the hook prior to the
piston having reached the one-way lid.
[0043] This embodiment requires, however, that the one-way lid is closed prior to the tap
water supply being turned on to reload the spring; if the one-way lid is not closed,
the tap water intended to load the spring loaded container 100 will simply be lost.
It may prove difficult to provide an extra means for closing the one-way lid, but
it is also possible to provide a further valve downstream the one-way valve, the further
valve providing a seal during loading of the spring loaded container.
[0044] Therefore, in still another embodiment providing for a dual flush, there is no extra
arresting means between the hook and the piston. Instead, the one-way lid may be controlled
to shut off the flow of liquid out through the one-way lid once a desired amount of
liquid has been ejected out through the one-way lid.
1. A spring loaded container (100) for achieving a flush of a toilet bowl, said container
(100) comprising a main body (110), a piston (120) reciprocally situated in said main
body and being loaded by a spring (140) such that the piston will exert a force on
water housed within the main body, the spring loaded container further comprising
an inlet (210) and an outlet (150), the outlet (150) being connected to the toilet
bowl, characterized by holding means (200) designed to hold the piston in a position corresponding to a
maximum volume of water being housed within the main body.
2. The spring loaded container (100) according to claim 1, wherein said piston (120)
does not exert a force on the water housed within the main body (110) when the piston
(120) is in a position corresponding to a maximum volume of water being housed within
the main body.
3. The spring loaded container (100) according to claim 1 or 2, wherein the outlet (150)
is connected to an ejector (270) designed to move liquid from a cistern to the toilet
bowl to be flushed.
4. The spring loaded container according to any one of the preceding claims, wherein
the holding means (200) is arranged in a central position of the piston (120).
5. The spring loaded container according to any of the preceding claims,
wherein the outlet (150) is provided with a one-way lid (230), the lid being arranged
such that it will close as it is engaged by the piston (120).
6. The spring loaded container according to any of the claims 1-4, wherein the outlet
(150) is provided with a controllable valve, such that a flow of liquid from the spring
loaded container may be interrupted at any time.
7. A toilet having a flush tank including at least one spring loaded container according
to any of the preceding claims.
8. The toilet according to claim 7, wherein the flush tank comprises two spring loaded
containers.
9. The toilet according to claim 8, wherein a first of the spring loaded containers is
connected and sized to provide a large flush and a second of the containers is arranged
and sized to provide a small flush.
10. The toilet according to claim 7 or 8, wherein the spring loaded containers have roughly
the same volume, and wherein a small flush is effected by emptying one of the spring
loaded containers, whereas a large flush is effected by emptying both of the spring
loaded containers.