Note: Descriptions are shown in the official language in which they were submitted.
PORTABLE IOILET WI~ RATTERY OPERAl~D FIUS~ AssEMsLY
BACKGROUND OF ~E_INVENTION
~ his invention relates generally to portable toilets and more
particularly to a portable toilet which carries its cwn power fi~pply for
operating the flush assembly. U.S. Patent 4,641,383 illustrates a
portable toilet of the particular typP to which this invention relates.
It is conventional practice when .flushing portable toilets of this type
to utilize manually operable pumps of the bellows type for pumping flush
water from a water storage tank in the toilet into the toilet bowl.
Pumps of the bellows tyFe are illustrated in prior ~.S. Patents 3,570,018
and 3,949,430, all of said prior patents being assigned to the assignee
of this application.
Pwnps of of the bellows type are lcw cost items which allow water
conservation to be observed and have proved to be satisfactory for the
needs of portable toilet users. However, there is a need for improved
power operated flush assemblies in portable toilets in order to provide
for lmproved flushlng of the toilet and also to provide for more
efficient use of the flush water supply and enable the use of portable
toilets by handicapped or elderly persons that do not have the strenyth
or other physlcal ability to operate a bellows punp.
' ~.S. Patent 4,185,337 also assigned to the assignee of this
application, shows a portable toilet with an electrically operated flush
apparatus but the flush apparatus illustrated in this patent req~ires an
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external source of power and involves a continuous flush which has
limitations from an efficiency standpoint.
It is the object of this invention, therefore, to provide an
improved portable toilet with a battery operated flush assembly.
SUMMA~Y OF THE INVENTION
The present invention is directed to a new and improved portable
toilet which includes a flush assembly operated by the batteries carried
on the toilet. me battery operated flush mechanism is operated by
depressing a hollow cap member, ~ometimes termed a "palm button" and
there is a novel lock and unlock mechanism associated with the palm
button that is operable to selectively lock the palm button in a position
in which it cannot ~e depressed to flush the toilet and an unlocked
position in which it ~an be selectively depressed to operate the flush
mechanism.
The mechanism includes a "pulsing circuit ~oard" which provides
tw~ functions, namely, it senses low batteries ~nd turns on a warning
light before the batteries become too low to operate the flush mechanlsm.
In addition, it turns the pump drive motor on and off. me "pulsing
circuit board" is operated to turn the motor off and on at predetermined
time intervals, such as every second, so as to obtain a "pulsed flush."
This type of flush is desirable in that it provides both high velocity
water and low velocity water on the flush ledge of the toilet bcwl to in
turn provide for a uniform wetting of the bowl by the flush water.
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Specifically, the invention relates to a portable
toilet which includes a seat section having a bowl with a
bottom discharge opening and a chamber containing flush
water for rinsing the bowl and flushing the contents thereof
through the discharge opening, pump means operable to move
water from the flush water chamber into the bowl, an
enclosure for the pump means having a lower flush water
inlet communicating with the flush water chamber, electric
motor means drivingly connected to the pump means, battery
means mounted on the seat section, means for selectively
electrically connecting the battery means to the motor
means, the electrical connecting means including a circuit
having an "on/off" switch and further including a switch
actuating member movably mounted on the seat section for
movement between two positions corresponding to "on" and
"off" positions of the switch, closure means for the flush
water inlet movable between open and closed positions, the
closure means i.n the closed position blocking flow of flush
water from the chamber into the enclosure and then into the
bowl, the closure means in the open position enabling flow
of flush water from the chamber into the enclosure, and
means operable in response to movement of the actuating
member to the position corresponding to the "on" position of
the switch for moving the closure maans to the open
position.
In addition, the improved flush apparatus of this
invention may include an axial flow pump which employs a
rotatable propeller which
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includes a plurallty of short spiral vanes. When the propeller is
rotated rapidly about its axis, the vanes push the water upward~y into a
spiral cavity within the pump housing which in turn directs the flush
water into a tube which llfts the water about twelve inches into the top
of the toilet b~wl. m e pump structure is advantageous in that it
provides maximum efficiency in terms of use of battery current to lift
relatlvely small amounts of water relatively short dlstc~nces and pulse it
lnto a toilet bowl. This arrangement provides for prolonged service life
of the flush batteries and in addition minimizes the need for frequent
refilling of the toilet flush water tank.
In the bellows type flush now in common use, it is necessary for
the user to apply cibout a thirty-five pound force to the bellcws. If the
force is too hard, the flush water shoots out of the supply tube and over
the toilet bcwl. If the push is not hard enough, a less than
satisfactory flush is obtained. The electric flush assembly of this
invention requires about a five pound push and provides for repeatable
uniform wettir~ and thorough flushing of the toilet bawl.
One of the hazard~ involved in using a portable toilet is the
possibility of spilling the flush water during transport of the toilet.
Unless the flush water is blocked from flowing into the toilet bowl
during transport of the toilet, the flush water will inevitably leak from
the bowl while the toilet is being carried. One of the advantages of the
battery operated flush of this invention is that a closure is provided to
open the water flcw path frorn the flush water tank to the toilet bcwl
upon initiation of the flush and 1nn~diately close the flow pa'ch at the
end of the flush to thereby prevent undesirable drainage of water through
the pump and the toilet bowl during transport of the toilet.
Other tollets have used a check valve which constitutes a
restriction in the flow path between the pump and toilet bowl. In a
toilet with a manually operated flush mechanism, such a restriction is
not objectionable because the same large force that is necessary to
operate the manual flush mechanism is also operable to open the check
valve However, in the battery operated assembly of this invention, the
objective i5 to use as little power as possible during flushing so as not
to require frequent changing of the batteries. miS is accomplished in
the battery operated flush assembly of this invention by avoiding the
check valve restriction and using a closure which normally closes the
flow path between pump and b~wl and which is manually opened during
initiation of a flush by the same actuator movement that closes the
battery switch that in turn initiates the flush operation.
The principal object ~f this ~nvention, therefore, is to provide
an improved battery operated flush assembly for port~ble toilets which
provides for improved flushing action, efficient use of batteries,
efficient use of flush water, and prevents leakage of flush water during
transport of the toilet.
Further objects, features and advantages of the invention will
become apparent from a consideration of the following description and the
appended claims, when taken in connection with the accompanying drawing
in which;
Figure 1 is a top view of the portable toilet oE this invention,
with a portion of the seat broken away to show the toilet bowl~
Figure 2 is an enlarged transverse sectional view of the portable
toilet of this invention as seen from substantially the line 2-2 in
Figure 1;
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Figure 3 is an enlarged transverse sectional view of the portable
toilet of this invention as seen from substantially the line 3-3 in
Figure 2;
Figures 4 and 5 are horizontal sectional views of the flush
assembly in the portable toilet of this invention as seen from
subst~ntially the lines 4-4 and 5-5, respectively, in E`igure 6;
Figure 6 is an enlarged vertical sectional vlew o~ the portion of
the toilet fihown in Figure 1 in which the flush assembly of this
invention is embodied;
Figure 7 is another vertical sectional view of the flush assembly
of this invention;
Figures 8 and 9 are exploded perspective views of portions of the
flush assembly illustrated in Figures 6 and 7;
Figure 10 is a circuit diagram illustrating the electric circuit
in the flush assembly of this invention; and
Figure 11 is a graph illustrating the pulsed flush in the flush
assembly o~ this inventlon in which voltage and velocity are plotted
against time.
With reference to the drawing, the improved portable toilet of
this invention, indicated generally at 10, is illustrated in Figures
and 2 as including a seat section 12 which separably mounts on a holding
tank section 14 in a conventional~manner. ~e seat section 12 includes a
bowl 16, and an overlying seat 18 and a cover 20 whlch are hingedly
mounted on the section 12. A flush water storage tank or chamber 22 is
provided within the interior of seat section 12 and is filled with fresh
water via a fill port which is covered ~y a removable cap 24.
A pumping mechanism indicated generally at 26 is provided for
pumping fresh water from the water storage chambex 22 into the bowl 16 in
order to flush the toilet. The bowl 16 includes a bottom discharge
opening 28 at its lowex end and a flush ledge 30 near its upper end on
which flush water is deposited for flow along the ledge and inwardly off
the ledge so as to unifoxmly wet the b~wl 16. me dischaxge opening 28
registers with an inlet opening 32 ~Figure 3) in the top wall of holding
tank 14. Opening 32 is closed by a slide valve 34 mounted wlthin the
interior of the holding tank 14. Because of the separable mounting of
the two sections 12 and 14, the holding tank section 14 can be removed
fox dumping.
The pump mechanism 26 includes a battery operated pump assembly
36 (Figure ~) which is mounted on the seat section 12 in an upwardly
facing opening 38 in what amounts to the right rear corner of the top
~urface 40 of the seat section 12. A sealing ring 41 provides for a
fluid tight assembly of the pump assembly 36 with the seat section 12.
The pump assembly 36 includes a housing 42 which is generally
upright and includes a continuous side wall 44, a top cover plate 46, an
intermediate plate 47, and a ~ottom wall 48. Between the walls 46 and
4B, the housing 42 is fluid tlght. An enclosure 49 below the housing 42
is open at its lower end and carries a sealing closure plate 50 which
normally clo6es the lower end of the enclosure 49.
Between the plates 46 and 47, the housing 42 defines a battery
chamber 52 and between the plate 47 and bottom wall 48, the housing 44
defines a chamber 54 in which an electric motor 56 is housed having a
downwardly extending drive shaft 58 on which a pump propeller 60 is
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m~unted. me propeller 60 consists of a bullet shaped body 62 having
short spiral vanes 64 formed on its outer surface.
Telescoped over the upper end of the housing 42 is an actuator
cap 66, sometimes referred to as a ~palm button" because it is intended
to be depressed with the palm oE the hand. The actuator cap has a top
wall 68 and a depending skirt 70 and i6 open at its lower end 60 that it
can readily be telescoped over the upper end of the housing 42.
The lower end of the actuator cap skirt 70 is formed at a
plurality of circumferentially spaced points with inwardly directed
projections 72 which, when the cap 66 is manually telescoped downwardly
over the housing 42, will snap over a corresponding number of outwardly
extending projections 74 form~d on the housing 42. The cap 66 is formed
of a relatively thin gauge deflectable plastic material so that the skirt
70 will readily deflect outwardly and spring back inwardly as the
projections 72 pass cver the projectlons 74. Similarly, the skirt 70 can
be manually grasped and squeezed to deflect the lower end of the skirt 70
outwardly so as to enable the projections 72 to pass over the projections
74 when it is desired to remove the actuator cap 66 from the housir~ 42.
Four batteries 76 (Figure 9) are mounted on the plate 47 and
housed within the chamber 52~ Uprlght, irregularly shaped, paLtitions 78
on the plate 47 function to maintain the batteries 76 in upright
positior~ and also cooperate with the housing 42 and its side wall 44 to
define an enclosure in which a circuit board 80 is housed, the enclosure
having a top wall 82 in which an opening 84 ls Eorn~d for a purpose to
appear presently.
The circuit board 80 supports most of the components of the
electrical circuit indicated generally at 86 in Figure 10. The circ~lit
86 has leads 88 connected to the batteries 76 and leads 90 connected to
the electric motor 56. The circuit 86 also includes a warning light LED
92 which is mounted on the wall 82 in alignment with the opening 84 which
is also aligned with an opening 94 in the tc~p wall 68 oE the actuator cap
66. The circuit B6 also includes a magnetic reed switch 96 which is
mounted in the cha~er 52 on the wall 44 of the housing 42 at a position
in which, when the actuator cap 66 i6 depressecl, a magnet 98 carried by
the actuator cap skirt 70 will actuate the switch 96 so that it will open
and close continuously so long as the cap 66 is maintained in its
depressed position. This opening and closing takes place rapidly, for
example, on a one-second cycle basis, as illustrated in Figure 11. As
will be described in detail hereinafter, such a condition of the switch
96 will provide for a pulsed flow of flush water from the chamber 22 to
the toilet bowl 16. The function of the light 92 is to visually warn the
toilet user, that the batteries 76 are low and replacement should be
considered.
A cover plate seal 100 mounts the cover plate 4h on the upper end
of the housil~ 42 so as to maintain the chamber 52 in fluid tight
condition. A compression spring 102 telescoped over a short post 103 on
the plate 46 is maintained in a compressed condition by a retainer cap
104 which has a central round projection 105 ln a tongue and groove
relationship with a downwardly extending projection 103 on the top wall
,68 of the actuator cap 66. The tongue and groove relationship prevents
rotation of the cap 66 on the housing 42.
A generally circular thwnb wheel 106 has a toothed portion 108
(Figures 6 and 8) which projects transversly through a slot 110 in the
actuator cap skirt 70. A cap shaped central portion 112 of the thumb
wheel 106 telescopes downwardly over the retainer projection 105. mis
mounting enables rotation of the thumb wheel about the projection 105.
As shc~wn in Figures 6 and 8, the cc)ver plate 46 i6 formed with a
plurality of upstanding posts 114 which are arranged concentrically
around the thumb wheel retainer 104.
As shc~n in Figure 5, the posts 114 are vertically aligned with a
plurality of openings 116 in the thumb wheel 106, in one rotated position
of the thumb wheel 106, thereby enabling the actuator cap 66 and the
thumb wheel 106 to be moved dc~nwardly relative to the posts 114. This
rotated position of the thumb wheel 106 c,orresponds to an "on" condition
of the switch 96 because it enables the actuator cap 66 to be moved
dc~ rdly to a position in which the magnet 98 will actuate the switch
96.
In another rotated position of the thumb wheel 106, the portions
of the thumb wheel 106 ~etween the openings 116, are aligned with the
posts 114 so that if depression of the actuator cap 66 is attempted, the
thumb wheel 106 will engage the posts 114 and prevent movement oE the
magnet 98 to a positlon in which it will actuate the switch 96. Thus,
such a moved position of the thumb wheel 106 corresponds to an "off"
c,ondition of the switch 96 and effectively locks the cap 66 in a position
in which the toilet can not be inadvertently flushed.
When the actuator cap 66 is depressed to actuate the switch 96
whlch energizes the motor 56 so as to drive the drive shaft 58 50 as to
rapidly rot,ate the propeller 60 about the vertical axis of the shaft 58,
it i5 also necessary to move the closure plate 50 at the lower end of the
housing 42 to the open positlon shown in broken lines in Figure 7. As
shown in Figure 7 the closure plate 50 includes a shaft 122 which is
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rotatably mounted m a hinge 124 formed on the lcwer end of the enclosure
49. The opposite end of the closure plate 50 is connected to a tension
spring 126 which is mounted on the enclo6ure 49. The spring 126
maintains the closure plate 50 in a normally closed position. In order
to move the closure plate 50 to its open pos1tion, the closure plate ha~
to ~e moved against the tension for oe of the spring 126.
As shc~n in Figure 4, the housing wall 44 opposite the battery
chamber SZ has an inwardly extending portion 130 which provides a
vertically extending space 132 within the cap 66 to one side of the
chamber 52. An actuating rod 134 for opening the closure plate 50 in
response to dc~rdrd movement of the actuating cap 66 is provided. The
rod 134 has its lower end 136 nested in a cavity in the free end 138 of
the closure plate 50. The rod 134 extends upwardly through the plate 47
and at its upper end carries a yeildable cover member 142 which engages
the underside of the cover plate 46. An actuator rod 140 on the
underside cf the top wall 68 of the actuator cap 66 i9 moveable
downwardly, in response to depression of the cap 66, through an opening
(not shown) in the cover plate 46 to engaqe the cover member 140 and move
the actuatinq rod 134 downwardly to in turn pivotally move the closure
plate 50 downwardly about the shaft 122 to an open position in which the
water in the flush water tcank 22 oommunicates with a p~p chamber 144
within housiny 49 in which -the propeller 60 i5 located. ~ stop member
143 is adjustably mounted on rod 134 to l~tt upward movement of the rod
134.
Rapid rotation of the propeller 60 about the vertical axis of the
clrive shaft 58 causes water from the tank 22 enterinq the chamber 144 to
be movecl rapidly upwardly in the chamber 144 into a spiral chamber 146
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thereabove for flow in a horizontal direction into the inlet end of a
tuke 146 which connects the pump to the toilet bowl 16. me outlet end
148 of the tube 146 is posltioned directly above and in line with the
flush ledge 30. As a result, pulses o~ water issuing from the tube
discharge end 148 will travel around the periphery of the bowl 16 on the
ledge 30, and a~ the water moving on the ledge 30 loses its momentum, and
as the velocity of the water decreases, the centrifugal force of the
water that is holding it on the ledge 30 and against the outer bcwl wall
150 above the ledge 30 (Figure 3) decreases and the water will gradually
run off the inner end of the ledge 30 and dcwn the bowl 16 toward the
outlet 28 so as to flush the bowl contents through the openlng 28 and
thoroughly wet the inner surfaoe of the kcwl 16 so as to accomplish the
desired complete flushing of the bowl 16. The normal high and low water
levels in the water chamber 22 are shown at A and B in Figure 7.
As shown in Figure 11, the circuit 86 operates to intermittently
reduce the voltage on the motor 56 from a maximum value to zero once
every second~ the time in seconds ~eing indicated by the numerals 1, 2,
3. This results in the velocity of the pulsed flush water being
similarly cycled in 1 second cycles between a maximum velocity and a
velocity only slightly greater than zero. The result is a pulsed action
of the water which is continuously repeatable in a uniform manner so that
the toilet user can flush the toilet 10 by moving the thumb wheel 108 to
the "on" position, subsequently depressing the actuating cap 66 and
maJntaining the actuating cap 66 in a depressed position for a desired
period of time necessary to accompllsh complete flushing of the bowl 16.
The operation of the actuator cap 66 can be repeated over the service
life of the toilet 10 with the kn~wledge that each flushing cycle will be
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a predictable repeat of previous cycles. ~nis uniformity of operation is
desirable from the standpoint of economic use of water from the tank 22
and economic use of the batteries 76 over a prolonged service lie.
When the batteries 76 become low enough to consider replacement,
but prior to the time the batteries become so low that they will not
operate the circuit 86, the light 92 will so indicate.
The elements and operation of the circuit 86 will now be
described with reference to Figure 10. The circuit 86 performs the
functions of providing an indication of low battery voltage and modulates
the voltage applied to the motor 56 to provide a pulsed water output, as
previously described. The circuit 86 is divided into two functional
subcircuits, a lcw battery indicator circuit 151, and a pulsing circuit
152, both carried by the circuit board 80.
The low battery indicator circuit 151 includes a voltage detector
154 which is powered by battery voltage flowing through a diode 156. The
voltage detector 154 provides a constant voltage output at the terminal
158 while the battery voltage is within a given range. If however,
battery voltage falls below a predetermined level, the terminal 158 is
turned off. The signal from terminal 158 is applied to the base terminal
of the transistor 160. The emitter o the transistor 160 is at battery
voltage once the switch 96 is closed. The low battery warning T~n 92 is
connected between battery ground and the collector of the transistor 160.
In operation, the transistor 160 acts as a switch which controls
current flow through the LED 92, based on the ~ignal applied by the
voltage detector 154. When the switch 96 is open, no current Elows
through the LED 92. When the switch 96 is closed while the battery
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voltage is at a high level, the voltage detector 154 provides a signal
which prevents current flow through the LED 92. If, however, battery
voltage applied to the emitter terminal goes below a predetermined level,
terminal 158 is turned off which allows current to flcw through LED 92
causing it to illuminate. Accordingly, the low battery indicator circuit
151 provides a visual indication to the user of a low battery voltage
condition.
The pulsing circuit 152 includes three series connected op-amps
or inverters 162, 164, and 166. A feedback signal is applied to inverter
162 through resistor 172 from the output of inverter 164 through a
capacitor 168, a-nd from the output of inverter 166 through a resistor
170. Since the charging of the capacitor 168 is time dependent, the
feedback voltage applied to the invertor 162 changes with respect to
time, causing the output from invertor 166 to be a square wave with its
period determined by the values of the capacitor 168 and the resistors
170 and 172. The transistors 174 and 176 act as switches which handle
motor current. The positive terminal of the motor is normally connected
directly to the battery positive terminal while the ground connection is
switched by the circuit to provide the desired pulsed output.
From the above description it is seen that this invention
provides a portable toilet 10 which includes a battery operated flush
assembly. Furthermore, the battery operated flush assembly provides for
a "pulsed" action of the flush water in the toilet bowl 16 to provide for
more efficient and improved flushing action. This is accomplished by
using the improved axial flcw pump which operates to lift relatively
small amounts of water relatively short distances and pulse it into the
toilet bowl. All of ~lese advantages are obtained while still
maintaining efficient use of the batteries that operate the flush
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mechanism and without risking leaking of the flush water fr~m the toilet
during transport.
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