BACKGROUND OF THE INVENTION:
[0001] Many cities are attempting to conserve water by reducing the amount used in each
toilet flushing. One approach is to apply a vacuum to the toilet bowl outlet near
the beginning of each flushing to suck out water and debris to flow into a drain pipe.
One old patent, U.S. 380,854 to Boyle, issued April 10, 1888, describes a vacuum assisted
toilet, where the bowl outlet includes upper and lower traps that are always sealed
against the passage of air. The presence of two traps can allow all water from the
toilet bowl to be siphoned into the drain, and allow sewer gas to leak through the
toilet bowl into the environment. A vacuum assisted toilet which avoided possible
loss of all water in the toilet bowl while effectively using the applied vacuum, would
be of considerable value. It would also be valuable if such toilet could operate with
a water source that could lie at a range of levels instead of only high above the
level of the toilet bowl.
SUMMARY OF THE INVENTION
[0002] In accordance with one embodiment of the present invention, a vacuum assisted toilet
is provided which is highly effective and reliable. The toilet includes a bowl outlet
with a pair of trap devices and a trapway between them to which a vacuum is applied
during flushing. The lower trap device includes a trapping region that completely
fills with water during flushing to provide a vacuum seal, but which is unobstructed
to the flow of air along its top when no water is flowing therethrough. The lower
trapway prevents dissipation of the vacuum applied to the trapway during flushing,
and prevents the possibility of siphoning out all water from the toilet bowl.
[0003] In one toilet, a container apparatus is provided which holds most of the flushing
water, which includes a diaphragm device sealed to the walls of a container and moveable
therein. The diaphragm device divides the container into a vacuum chamber forming
the vacuum source and a water chamber. The water chamber is initially filled with
most of the flush water before flushing. At the beginning of flushing, water rapidly
flows out of the water chamber into the toilet bowl, allowing the diaphragm device
to rapidly contract the water chamber and consequently expand the vacuum chamber to
produce a vacuum therein that is coupled to the trapway. A biasing device such as
a spring or weight moves the diaphragm device as the water chamber empties. The biasing
device can apply a considerable pressure to the water in the water chamber, so the
water chamber can lie even below the level of the toilet bowl.
[0004] Another vacuum source includes a diaphragm device that can expand and contract the
volume of a vacuum chamber, with the diaphragm device being moved by a water powered
actuator. The actuator, which is initially empty of water, is coupled through an inlet
valve to a pressured household water supply at the beginning of flushing. The pressured
water rapidly moves the actuator to expand the vacuum chamber and apply a vacuum to
the toilet bowl outlet. Water in the water powered actuator can slowly drain out after
each flushing.
[0005] The novel features of the invention are set forth with particularity in the appended
claims. The invention will be best understood from the following description when
read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Fig. 1 is a partial sectional isometric view showing a vacuum assist toilet constructed
in accordance with one embodiment of the present invention.
[0007] Fig. 2 is a sectional side view of the toilet of Fig. 1.
[0008] Fig. 2A is a sectional side view of a lower trapway device constructed in accordance
with another embodiment of the invention, which can be used with the toilet of Fig.
1.
[0009] Fig. 3 is a partial sectional view of the toilet of Fig. 1, showing the container
apparatus thereof.
[0010] Fig. 4 is a simplified sectional view of an inlet valve that can be used with the
apparatus of Fig. 3.
[0011] Fig. 5 is a sectional view of an air relief valve that can be used with the apparatus
of Fig. 3
[0012] Fig. 6 is a partial sectional isometric view of a toilet constructed in accordance
with another embodiment of the invention.
[0013] Fig. 7 is a sectional view of the vacuum source of the toilet of Fig. 6.
[0014] Fig. 8 is a sectional view of a refill device of the toilet of Fig. 6.
[0015] Fig. 9 is a partial sectional isometric view of a toilet constructed in accordance
with another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] Fig. 1 illustrates a low profile toilet 10 which includes a container apparatus 12
that contains flush water. A person can move a lever 14 to open a flush valve 16 that
allows water stored in the container apparatus to move through a flush conduit 18
into a toilet bowl 20. Water flushed into the toilet bowl raises the water level from
an initial level 22, to cause water and any debris in the toilet bowl to flow out
of a toilet bowl outlet 24 that carries water and waste to a drain 26 that connects
to a sewer system. During a flushing, water flows rapidly into the toilet bowl and
water and debris moves out of it. During a period of perhaps forty-five seconds after
a flushing, water from a household water supply 30 flows through an inlet valve 32,
with most of the water flowing into the container apparatus 12 to refill it and ready
it for the next flushing. Part of the inflowing water flows through the flush conduit
18 into the toilet bowl 20 to refill it to the initial level 22. In large cities,
the pressure of water supply to the inlet valve 32 is always a plurality of psi (pounds
per square inch) and is usually much more than 20 psi (1.4 bar).
[0017] The toilet 10 is a vacuum assisted type, wherein a vacuum from a vacuum source 40,
which happens to be part of the container apparatus 12, is applied through a vacuum
conduit 42 to the toilet bowl outlet 24 to apply a vacuum therein during flushing
of the toilet. The vacuum draws water and waste from the water pool 44 in the toilet
bowl to efficiently flush the toilet bowl.
[0018] As shown in Fig. 2, the toilet bowl outlet 24 includes an upper trap device 44 coupled
to the toilet bowl, and a trapway 46 extending from the upper trap device to a lower
trap device 50 that leads to the drain 26. The lower trap device includes a conduit
portion 51 extending at an upward incline in a downstream direction. The top 52 of
the inside of the upstream end of the conduit portion lies slightly higher than the
bottom 54 of the downstream end of the upwardly inclined conduit portion. The result
is a lower trap pool 56, with the top of the pool lying a small distance A below the
uppermost location 52. This leaves a trap region 58 that is initially open to allow
gas to flow therethrough, which avoids siphoning out water from the toilet bowl between
flushings. However, early during a flushing, water fills the lower trap device to
above the location 52, which prevents a vacuum applied to the trapway 46, from being
dissipated through the drain 26.
[0019] The distance A is preferably small, being less than half the width B of the trapway
and of the conduit forming the lower trap 50. The traps and trapway generally have
a considerable minimum width such as two inches (5 cm) to assure the reliable flow
of debris therethrough. A small gap A such as one-half inch (1.3 cm) is desirable
so that a vacuum can be established in the lower trapway near the very beginning of
flushing, when water first flows out of the toilet bowl.
[0020] The end 42e of the vacuum conduit can be placed anywhere that it is in direct communication
with the trapway 46. Applicant prefers to make the connection in a cavity 60 lying
above the path of water flowing through the trapway to resist the entrance of water
into the vacuum conduit.
[0021] Fig. 2A illustrates another lower trap device 62 which includes a conduit portion
63 extending at an upward incline (in a downstream direction) to a sufficient height
to create a pool of water 64 that always blocks the flow of air. However, a bypass
air conduit 64 connects locations on opposite sides of the water pool, through a valve
65 that is normally open. A valve actuator 66 is moved at substantially the beginning
of a flushing, to temporarily close the valve and block air flow through it. The particular
valve actuator 66 is moved by a chain 67 that is pulled when the flush lever 14 (Fig.
1) is moved. However, the valve actuator could be actuated by a vacuum applied along
line 42, or by the inflow of water along pipe 30, or other event occurring within
about one or two seconds after the beginning of a flushing. The valve 65 remains closed
for a period such as six seconds after it is first closed. This period is long enough
to avoid dissipating any vacuum applied, but is short enough to avoid syphoning out
water from the toilet bowl as it is refilled.
[0022] Fig. 3 illustrates details of the container apparatus 12 and of the vacuum source
40 thereof. The container apparatus includes a large container 70 and a valve box
72, the two of them being connected by a large transfer opening 74. A diaphragm device
76 is provided which is in the form of a diaphragm with a periphery 78 sealed to the
walls of the container to divide the container into a vacuum chamber 80 and a water
chamber 82. Between flushings, the water chamber 82 is completely filled with water.
A biasing device 84 in the form of a tension spring, tends to pull down the middle
86 of the diaphragm, which is rigidized by a plate 88. When the lever 14 is moved
to pivot a flush valve member to the open position shown at 90A, the flush valve 16
is opened and water lying in the valve box 72 and in the water chamber 82 can move
out of the flush conduit 18 to the toilet bowl to begin a flushing. As water flows
rapidly out of the water chamber 82 and valve box 72 of the container apparatus, the
diaphragm device 76 rapidly moves down to its down position shown at 76A. The spring
biasing device 84 assures rapid downward movement of the diaphragm device, as well
as creating a large pressure head, as will be described above. With the diaphragm
rapidly moving down, the vacuum chamber 80 rapidly expands in volume, creating a vacuum
therein which is coupled through vacuum conduit 42 to the trapway of the toilet bowl
outlet. Thus, as water begins flowing into the toilet bowl to begin moving water and
debris into the toilet bowl outlet, the vacuum source 40 applies a vacuum to the trapway
of the toilet bowl outlet to enhance the movement of water and debris out of the toilet
bowl towards the drain. The use of a vacuum to enhance flushing, reduces the amount
of flush water required to effectively flush the toilet bowl.
[0023] Towards the end of the flushing, when the diaphragm device reaches its down position
76A, the pressure of water in the water chamber 82 and valve box 72 of the container
apparatus decreases and the inlet valve 32 opens. Water then flows through the household
water supply pipe 30, through the inlet valve 32 into the valve box 72 and into the
water chamber 82 to refill it. As the water flows in through the inlet valve 32, the
pressure of the inflowing water raises the diaphragm device back up to the position
76, so that any further inflow of water would greatly increase the pressure of water
in the container apparatus. The inlet valve 32 then closes. While the inlet valve
32 is open, a portion of the water flowing through it flows through a refill pipe
92 and through the flush conduit 18 to a toilet bowl to refill the toilet bowl to
its original level.
[0024] Applicant uses a spring biasing device 84 which maintains a pressure of water in
the water chamber 82 at a pressure such as 1 psi (about 0.06 bar). Such a pressure
of 1psi provides the same pressure of water at the flush valve seat 94 as a tall water
tank where the level of water is twenty seven inches (68 cm) above the flush valve
seat. One advantage of such pressured water is that it allows the overall height of
the toilet to be low. For the particular toilet illustrated in Fig. 2, the container
70 lies above the top of the toilet bowl but at only a low height. However, the pressure
of the water results in the water flowing rapidly into the toilet bowl, which enhances
the flushing of water and debris out of the toilet bowl. The rapid outflow of water
also results in the diaphragm device 76 being rapidly lowered, to create a considerable
vacuum early during the flushing. The large head produced by the pressure of 1 psi
also enables the container apparatus 12 to lie at even a lower height, such as where
the flush valve seat lies many inches below the top of the toilet bowl.
[0025] Although applicant prefers to use a spring for the biasing device, it is also possible
to use a weight indicated at 96. However, if the overall diameter of the container
70 is about one foot (30 cm), then the weight would have to weigh about 113 pounds
(51 kg) to produce a pressure of about 1 psi. Although applicant shows one tension
spring, it is possible to use compression springs or leaf springs to press down the
diaphragm device. Instead of a diaphragm, it is possible to use a piston as the diaphragm
device, although it can be difficult to seal such a piston and to accurately guide
movement of a large diameter but small height piston. It may be noted that it is possible
for the diaphragm device 76 to not extend substantially horizontally, but to extend
at an angle to the horizontal.
[0026] The valve box 72 contains additional valves, including a pressure relief valve 100
which is set to open at a predetermined pressure such as 2 psi (0.12 bar), to prevent
destruction of the apparatus in the event that the inlet valve 32 remains open after
the pressure of 1 psi is reached in the water chamber 82. When the pressure relief
valve 100 opens, it allows water to flow up out of the valve box and through a tube
102 into the flush conduit 18 to flow water to the toilet bowl. An air escape valve
104 is also provided, which allows any air to escape, while preventing the escape
of water.
[0027] Fig. 4 is a simplified illustration of an inlet valve 32 which allows water to enter
the valve box 72 until a pressure of 1 psi is reached, and which then closes. The
inlet valve 32 includes a sliding valve member 110 which is urged towards the open
position by a spring 112. Air openings 114 allow ambient air pressure to be applied
to one end 116 of the valve member. The pressure of water in the valve box 72 is applied
to the opposite end 118 of the valve member. When the pressure of water in the valve
box reaches 1 psi, the pressure on the valve member end 118 is great enough to overcome
the force of the spring 116, to move an opening 120 in the valve member to a position
120A at which the valve is closed. The valve member 110 can operate another valve
(not shown) that supplies refill water to the toilet bowl. Of course, a wide variety
of valve constructions are known for closing a valve when a predetermined water pressure
is reached in the container.
[0028] Fig. 5 illustrates one example of an air escape valve 104. The valve 104 includes
a light weight ball 124 which tends to remain in the down position shown, to allow
air to flow around the ball and out through an outlet 126. However, when water rises
to the level of the ball, the ball floats on the water, and rises until the ball presses
against a surface 128, which closes the valve and prevents the outflow of water.
[0029] Figs. 6 illustrates another toilet 130 which employs a different container apparatus
132 and vacuum source 134. The container apparatus includes a water tank 136 of conventional
but low profile construction. A conventional toilet inlet valve 140 is provided of
the type that includes a float 142. Immediately after a flush valve 144 is opened
to start dumping water in the tank into the toilet bowl 146, the float 142 falls and
the inlet valve opens. The inlet valve then supplies pressured water through a pressured
water conduit 174 to the vacuum source 134 to activate it, as will be discussed below.
The toilet bowl outlet 150 is similar to that of Fig. 2, and includes upper and lower
traps connected by a trapway 152 with a vacuum conduit 154 connected to the trapway
to apply a vacuum thereto near the beginning of a flushing.
[0030] As shown in Fig. 7, the vacuum source 134 is connected to a pressured water conduit
174 and delivers a vacuum through the vacuum conduit 154 to the toilet bowl outlet.
The vacuum source includes a housing 156 which contains a pressured-water powered
actuator 158. The actuator includes a water vessel 160 and a water diaphragm 162 which
extends across the vessel to form a water chamber 166 below the water diaphragm. A
plunger 164 has a lower end attached to the middle of the water diaphragm and an upper
end attached to the middle of a vacuum diaphragm 170. The vacuum diaphragm 170 seals
the top of a vacuum chamber 172 formed largely by the housing 156. When pressured
water passes through the pressured water conduit 174 (when flushing begins), the water
presses upward against the water diaphragm 162 to raise it and the plunger 164, thereby
raising the vacuum diaphragm 170 as to its upper position 170A. A chimney 171 extends
above the water level in the tank. The rapid expansion of the vacuum chamber 172 results
in the creation of a vacuum therein, which is communicated through the vacuum conduit
154 to the toilet bowl outlet.
[0031] After a flushing, and after the toilet bowl has been refilled and the inlet valve
has closed, water in the water vessel 160 slowly flows out through the water conduit
174 to allow the vacuum diaphragm 170 to fall to its lower position to be ready for
the next flushing. As discussed above, as soon as the flush valve 144 (Fig. 6) opens
to start a flushing, water drops in the tank and the inlet valve 140 opens, and flows
pressured water through the conduit 174 to the vacuum source 134 to activate it. After
the tank 136 and toilet bowl 146 are refilled, water flows out of the vacuum source
134 through conduit 174 and through a tank refill device 182 into the tank 136.
[0032] The tank refill device, shown in Fig. 8, is connected in series with the pressured
water conduit 174, and has a leak opening 184 that allows water to leak slowly into
the tank. The vacuum source includes a weight 186 (Fig. 7) which presses down the
vacuum diaphragm 170, and through the plunger 164 presses down the water diaphragm
162 to supply pressure to water in the water chamber 166. The pressured water passing
out through water conduit 174, slowly leaks out of the leak opening of the tank refill
device, so that after perhaps thirty seconds the diaphragms 170, 162 will move down
to their lower positions. The water chamber 166 holds less than ten per cent of the
flush water held in the tank 136 (Fig. 6), so the water chamber 166 rapidly fills,
and can empty through leakage in a moderate time period. The tank refill device 182
(Fig. 8) includes a valve 186 which opens at a predetermined pressure such as 8 psi
to allow a rapid outflow of water from the conduit 174 into the tank after the vacuum
source is activated. The valve 186 prevents the buildup of a pressure of more than
about 8 psi in the vacuum source, to prevent damage to the vacuum source. However,
a pressure of about 8 psi will be applied to the vacuum source, so long as the water
supply pressure is above 8 psi (which is almost always the case) to assure rapid operation
of the vacuum source near the beginning of flushing.
[0033] Fig. 9 illustrates another toilet 190 which is similar in many ways to conventional
toilets with tall water tanks. The toilet 190 includes a plastic container 192 which
lies within a water tank 194. When an inlet valve 196 opens after a flushing operation,
water in the tank rises to a level indicated at 200. Water in the tank enters the
container 192 through an opening 202 near the bottom of the container to fill the
container to the level 200. Air in the container passes out through the top of the
container and downwardly through a vacuum conduit 204 to a bowl outlet of the construction
shown at 24 in Fig. 2. In Fig. 9, with the tank 194 and container 192 filled to a
level 200, a lever 204 may be depressed to begin the flush cycle. Depressing the lever
204 lifts a chain 206 to open a flush valve 208 and pass water from the tank into
the toilet bowl. Water in the plastic container 192 passes out through the opening
202 to flow out through the open flush valve 208. As the level of water in the container
192 drops, a vacuum is produced in the top of the container, which is transmitted
through the vacuum conduit 202 to the trapway.
[0034] Thus, the invention provides a vacuum assist toilet which is reliable and yet which
can reduce the amount of water required in a flushing. The toilet includes a toilet
bowl outlet with upper and lower trap devices connected by a trapway, with the toilet
applying a vacuum to the trapway at the beginning of a toilet bowl flushing. The lower
trap device has a top that is unobstructed to the flow of gas therethrough when no
water is flowing through the trapway, but which is sealed to the flow of gas when
water begins flowing out of the toilet bowl early during flushing. This contains the
vacuum in the trapway instead of dissipating it to the drain, and avoids later siphoning
off of all water in the toilet bowl. One vacuum source includes a diaphragm which
divides a container into vacuum and water chambers, with the water chamber being completely
filled before a flushing and containing at least fifty per cent of the water dumped
into the toilet bowl during a flushing (which does not include refill water that refills
the toilet bowl after water and debris passes out of the bowl). A biasing device biases
the diaphragm to pressurize the stored water, to rapidly expel the water and rapidly
create a vacuum applied to the toilet bowl outlet. The provision of a large volume
container which holds water under a substantial pressure (e.g. 1 psi) is useful even
in a non-vacuum assisted toilet, to provide flush water from a source that can lie
at a low level (even below the top of the toilet bowl) and/or to provide a source
of flushing water that empties the water vigorously into the toilet bowl. Another
vacuum source includes a diaphragm which is rapidly moved by a pressured water powered
actuator into which water rapidly flows at the beginning of a flushing, when an inlet
valve opens.
[0035] Although particular embodiments of the invention have been described and illustrated
herein, it is recognized that modifications and variations may readily occur to those
skilled in the art, and consequently, it is intended that the claims be interpreted
to cover such modifications and equivalents.
1. A toilet which includes a toilet bowl, a flush valve, a container apparatus which
holds at least some of the water which passes out of said container apparatus and
through said flush valve into said toilet bowl during a toilet flushing, an inlet
valve which supplies water to said container apparatus, and a toilet bowl outlet which
includes an upper trap device extending from said bowl and a trapway extending down
from said upper trap device to carry water and debris from said toilet bowl toward
a drain, characterized by:
said container apparatus includes a vacuum source coupled to said trapway, which
applies a vacuum to said trapway in response to a flushing, when water passes out
of said container apparatus through said flush valve and said toilet bowl into said
bowl outlet;
a lower trap device which connects said trapway to said drain, said lower trap
device being constructed to enable the flow of gas therethrough between flushings,
but to block the flow of air but not water during at least part of each flushing,
to contain said vacuum in said trapway so said vacuum can help draw water and debris
out of said toilet bowl.
2. The toilet described in claim 1 wherein:
said lower trapway includes an inclined conduit portion extending at an upward
incline in a downstream direction, with the top of the inside of the upstream end
of the conduit portion lying slightly higher than the bottom of the downstream end
of said inclined conduit portion, to provide a pool of water whose top lies slightly
below said top of the upstream end of the conduit portion when no water flows through
said conduit portion.
3. The toilet described in claim 1 or 2 wherein:
said lower trapway includes an inclined conduit portion extending at an upward
incline in a downstream direction, which contains a pool of water that always blocks
the flow of air therethrough, a bypass air conduit connecting said trapway to a location
downstream of said pool of water, a valve which opens and closes said bypass air pipe,
and a valve actuator which is responsive to the beginning of a flushing to temporarily
close said bypass air pipe.
4. The toilet described in claim 1, 2 or 3 wherein:
said container apparatus includes walls forming a container, a diaphragm device
with a periphery sealed to said container walls to divide said container into a vacuum
chamber forming part of said vacuum source and a water chamber, said inlet valve being
coupled to said water chamber to supply pressured water thereto that tends to move
said diaphragm to expand said water chamber and contract said vacuum chamber while
said inlet valve is open, and a biasing device which urges said diaphragm to move
to contract said water chamber and create a vacuum in said vacuum chamber when water
is rapidly flowed out of said water chamber.
5. The toilet described in claim 4 wherein:
said container apparatus also includes a sealed valve box which includes a transfer
opening that is connected to said water chamber and a flush valve seat opening coupled
to said toilet bowl;
said flush valve includes a flush valve member lying in said valve box, which moves
against and away from said flush valve seat opening.
6. The toilet described in any one of claims 1 to 5 wherein:
said container apparatus includes walls forming a vacuum chamber including a diaphragm
device that can move to expand and contract the volume of said vacuum chamber, said
vacuum chamber being coupled to said trapway;
a water powered actuator that is coupled to said diaphragm device to move said
diaphragm device in a first direction to expand said vacuum chamber, said actuator
being movable in a second direction to allow said diaphragm device to move to contract
said vacuum chamber;
said inlet valve is connected to said actuator to supply water rapidly thereto
that moves said actuator in said first direction at the beginning of a flushing cycle,
to rapidly expand said vacuum chamber at the beginning of a flushing cycle.
7. The toilet described in claim 6 wherein:
said container apparatus includes a tank which holds water which is rapidly flowed
into said toilet bowl at the beginning of flushing;
a biasing device which urges said diaphragm device in said second direction to
contract said vacuum chamber;
a tank refill device which couples said actuator to said tank, which allows water
in said actuator to drain into said tank as said biasing device moves said actuator
in said second direction.
8. A method for operating a toilet by rapidly flowing water into a toilet bowl and rapidly
flowing water and any debris out of the toilet bowl through an upper trap and down
along a trapway toward a drain during a flushing, characterized by:
establishing a lower trap device between the bottom of said trapway and said drain,
including maintaining a pool of water in a lower trapway conduit which blocks the
passage of air between said trapway and drain at least during the early stages of
a flushing, but allowing air to pass between said trapway and drain between flushings;
applying a vacuum to said trapway during the early stages of a flushing, to help
draw water and debris out of said toilet bowl.
9. The method described in claim 8 wherein:
said step of establishing a lower trap device includes maintaining said pool of
water at a level which is slightly less than required for a complete trap so air can
pass above said pool when the toilet is not being flushed, and during the early stages
of a flushing, allowing water flowing through said lower trap device to raise the
level of said pool to create a complete trap that blocks the passage of air.
10. The method described in claim 8 wherein:
said step of establishing a lower trap device includes maintaining said pool of
water so it blocks the passage of air when there is no flushing in progress as well
as during a flushing, establishing a bypass air conduit extending around said pool
of water between said trapway and drain, and closing said bypass air conduit at least
part of the time during a flushing.
11. The method described in any one of claims 8 to 10 wherein:
said step of applying a vacuum includes filling a water chamber with water and
expanding the volume of the water chamber by moving a diaphragm device against a biasing
force to reduce the volume of an air filled vacuum chamber lying on a side of the
diaphragm device opposite said water chamber, and allowing air in said vacuum chamber
to exit therefrom, all before a flushing;
at the beginning of a flushing, allowing water to rapidly exit said water chamber
and flow into said toilet bowl, to allow said diaphragm device to rapidly expand said
vacuum chamber while said vacuum chamber is connected to said trapway.
12. The method described in any one of claims 8 to 11 wherein:
said step of applying a vacuum includes rapidly flowing water to an actuator at
the beginning of a flushing, to cause said actuator to rapidly expand an air-filled
vacuum chamber which is coupled to said trapway.
13. A toilet which includes a toilet bowl, a flush conduit for passing water to said bowl,
a bowl outlet which is coupled to a drain, a source of flush water, and a flush valve
which is operable to flow water out of said source and into said flush conduit at
the beginning of a flushing, characterized by:
said source of flush water includes a container forming a water chamber and including
a diaphragm device which is movable to expand and contract said water chamber;
a biasing device which urges said diaphragm device to contract said water chamber,
to pressurize water in said water chamber.
14. The toilet described in claim 13 wherein:
said bowl outlet includes an upper trap device connected to said bowl, a lower
trap device connected to said drain, and a trapway connecting said trap devices;
said container forms a sealed vacuum chamber on a side of said diaphragm device
opposite said water chamber, so when said water chamber contracts said vacuum chamber
expands to create a vacuum therein, said vacuum chamber being connected to said trapway
to apply a vacuum thereto near the beginning of a flushing.