BACKGROUND AND SUMMARY OF THE INVENTION
[0001] This invention relates to portable toilets and is particularly concerned with a new
and improved arrangement for emptying the contents of the holding tank of a portable
toilet.
[0002] A number of commonly assigned patents disclose portable toilets of the type which
comprise a holding tank section and a seat section separably mounted on the holding
tank section. The seat section comprises a bowl with a bottom outlet which registers
with an opening in the top wall of the holding tank. When the two sections are mounted
together the bowl outlet is in sealed relationship with the opening in the top wall
of the holding tank. A valve in the holding tank is disposed at the opening and when
the valve is operated the contents of the bowl drop into the holding tank. The accumulated
contents of the holding tank are dumped from time to time at suitable sanitary disposal
stations.
[0003] One usual practice has been to provide a threaded boss circumscribing an outlet opening
and a threaded cap threaded onto the boss to close the opening. When the contents
are to be dumped, the cap is unscrewed and the waste materials poured out.
[0004] The present invention is directed to a new and improved arrangement for dumping the
contents of the holding tank, and one of its advantages is that the dumping procedure
is more convenient and can be accomplished with less concern for back-splashing of
the waste discharge.
[0005] Further advantages accrue in the disclosed preferred embodiment of the invention
in which the improved arrangement comprises a rotatably mounted discharge spout on
the exterior of the holding tank one end of which fits into an aperture in the top
wall of the holding tank and the other end of which is closed by a removable cap.
The aperture is locatedat one corner of the top wall of the holding tank and the end
of the discharge spout which fits into the aperture comprises a key. A mating key
is provided on the aperture, and the keys are constructed such that the spout can
be inserted into and removed from the aperture only in one rotational position. The
spout may be rotated about the axis of the aperture away from said one position over
a range of positions in which the inter-engaged keys prevent separation of the spout
from the holding tank. The holding tank comprises side walls which meet at the corner
of the top wall containing the aperture, these side walls being generally at a right
angle to each other. The aperture key is arranged such that the spout can be inserted
into and removed from it with the spout overlying the top wall and disposed generally
parallel to one of these two side walls. The spout may be rotated from this installation
and removal position approximately three-quarters of a full circle so as to overlie
the top wall in a position which is generally parallel with the other side wall. This
latter position constitutes a storage position for the spout. The preferred embodiment
is disclosed as a portable toilet of the type comprising a seat section which is separably
mounted on the holding tank section. The two sections are constructed such that they
cooperatively define a cavity forming a housing for the spout when the spout is in
the storage position. In this way the spout is essentially concealed from view when
the two sections are mounted together.
[0006] In order to dump the contents of the holding tank the two sections are separated
and the spout is rotated away from its storage position to a position pointing away
from the holding tank. The cap is removed, and the tank is tipped so that the waste
contents are discharged from the far end of the spout.
[0007] In order to promote a smooth flowing discharge which is substantially immune from
objectionable characteristics such as belching,a vent valve is provided on the wall
of the holding tank for venting the interior head space during dumping. The disclosed
embodiment of vent valve comprises a normally closed spring biased element with an
actuator positioned adjacentto a gripping portion of the toilet so that when the toilet
is gripped for dumping it is particularly convenient for the person to operate the
vent valve actuator concurrent with the grasping and tipping of the holding tank.
After the dumping procedure has been completed, the cap is screwed onto the spout,
and the spout is returned to its storage position.
[0008] The foregoing features, advantages and benefits of the invention along with additional
ones, will be seen in the ensuing description and claims which should be considered
in conjunction with the accompanying drawings.
[0009] The drawings disclose a preferred embodiment of the invention according to the best
mode contemplated at the present time in carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
Fig. 1 is a perspective view having a portion broken away of an embodiment of portable
toilet comprising principles of the present invention.
Fig. 2 is an enlarged vertical sectional view taken substantially in the direction
of arrows 2-2 in Fig. 1.
Fig. 3 is a horizontal sectional view, on a reduced scale, taken in the direction
of arrows 3-3 in Fig. 2.
Fig. 4 is a partly exploded perspective view, on an enlarged scale, of one portion
of Fig. 1.
Fig. 5 is a top plan view of one element shown by itself.
Fig. 6 is a right side view of Fig. 5.
Fig. 7 is a front view of Fig. 5.
Fig. 8 is a view taken in the direction of arrows 8-8 in Fig. 7 and enlarged.
Fig. 9 is a perspective view illustrating the dumping procedure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Fig. 1 illustrates a portable toilet 10 embodying principles of the invention. The
toilet comprises a seat section 12 which separably mounts on a holding tank section
14 in a conventional manner. Fig. 1 shows the two sections separated. The seat section
12 comprises a bowl 16 and an overlying seat 18 and cover 20 which are hingedly mounted
on this section. A flush water storage tank or chamber (not viewable) i s provi de
d within the interior of seat section 12 and it may be filled with fresh water via
a fill port 22 which is covered by a removable cap 24. A pumping mechanism 26 is also
provided for pumping fresh water from the water storage chamber into bowl 16 for use.
The bowl comprises a bottom outlet (not viewable) which registers with an inlet opening
28 in the top wall of holding tank 14. Opening 28 is closed by a slide valve 30 mounted
within the interior of the holding tank. The slide valve is operated by a handle 32
which is disposed at the front wall of the holding tank section. In order to open
valve 30 the operating handle is moved in the direction of arrow 34. As valve 30 slides
open, the contents of bowl 16 drop into the holding tank. Thereafter the operating
handle is moved in the opposite direction to close valve 30. In this way holding tank
14 accumulates waste contents for later disposal at a suitable sanitary disposal station.
Because of the separable mounting of the two sections 12 and 14 the holding tank section
14 can be removed for dumping.
[0012] Dumping of the holding tank contents is accomplished through a discharge spout 36
on holding tank 14. Spout 36 is a hollow tubular element having a right angle bend.
One end is operatively engaged with the holding tank while the opposite end is closed
by a removable cap 38. Details of the spout construction can be best seen in Figs.
4 through 8.
[0013] The end of the spout on which cap 38 is disposed is provided with an integrally formed
screw thread 40. Cap 38 has a similar thread which allows the cap to be screwed onto
the end of the spout to close it. When the contents are to be dumped the cap is unscrewed
and removed. Preferably a circular sealing gasket 42 is lodged within cap 38 so as
to provide a seal between the end wall of the cap and the edge 44 of the spout at
the discharge opening when the cap is fully tightened on the spout.
[0014] The opposite end of the spout is of a generally circular shape but it comprises a
multi-lobed key 46. Specifically the key 46 comprises six circumferentially spaced
lobes which are identified by the reference numerals 46a, 46b, 46c, 46d, 46e, and
46f. It also comprises a circular groove 48 adjacent to key 46 for an 0-ring gasket
seal 50.
[0015] The holding tank wall is provided with a circular walled aperture 52 within which
the keyed end of spout 36 is disposed. A complementary mating key 54 (shown in phantom
in Fig. 8) is disposed on the wall of aperture 52. Key 54 allows the spout to be fully
inserted into aperture 52 only when the two keys are in circumferential registry.
The arrangement of key 54 in relation to the holding tank is such that circumferential
registry of the two keys 46, 54 occurs with the spout in the position shown in Fig.
4.
[0016] It will be observed that the holding tank has a generally rectangular shape and that
the aperture 52 is provided in the top wall at one corner. Thus the installation position
of the spout is such that the spout overlies the top wall and is generally parallel
to the far shorter side wall as viewed in Fig. 4. The construction of aperture 52
and key 54 is such that when the spout is fully inserted into the aperture the key
46 is disposed just beyond the key 54. At this point the 0-ring gasket 50 is engaged
with the wall of the aperture so that a leakproof joint is thereby provided. Next
the spout is rotated in the direction of arrows 56. As key 46 leaves its circumferential
registry with key 54, certain portions of the individual lobes of the keys are always
in interlocking engagement which prevents the spout from coming out of the aperture.
The dimensional relationships are such that this is true over all positions of a full
circular revolution of the spout about the aperture. However, the illustrated construction
is such that the operative range is less. When the spout has been rotated three quarters
of a revolution from its insertion position, it occupies another position which once
again overlies the top wall but is now parallel to the nearer longer side of the holding
tank as viewed in Fig. 4. This is also the position which is illustrated in Fig. 1,
and it constitutes a storage position for the spout.
[0017] In the storage position of the spout the two section 12 and 14 may be mounted together.
The two sections cooperatively define at their confronting surfaces a cavity which
forms a storage housing for the spout when the spout is in the stored position. The
illustrated construction is such that one portion of the storage housing may be considered
as comprising the area identified by the reference numeral 58 in holding tank section
14 while the remainder is defined in section 12 by the portion designated by the reference
numeral 60. The cavity forming the housing is integrally molded with the molded plastic
sections 12 and 14. As can be seen in Fig. 4 a depression 62 is fashioned in the top
wall of the holding tank. When spout 36, with cap 38 attached, is rotated to the storage
position the lower edge portion of the cap lodges in the depression 62 and in this
way the depression defines a locator for the storage position of the spout.
[0018] For dumping, seat section 12 is separated and removed from holding tank section 14
and the holding section is taken to an appropriate sanitary disposal station. The
spout is swung away from its storage position and cap 38 is removed. :The spout will
typically be pointed away from the holding tank and will not normally come close to
the installation-removal position. In other words rotation to the installation-removal
position would be contrary to the objective of dumping the tank, and therefore accidental
separation of the spout from the holding tank is essentially impossible. Moreover,
when the spout is in other than its storage position, the two sections 12, 14 cannot
be mounted together. Fig. 9 illustrates a typical dumping procedure and in that procedure
the spout has been rotated from its storage position only about 180°. This would probably
be the most amount of rotation, and other typical positions would be somewhat less.
[0019] In order to promote a reasonably smooth discharge flow of the waste contents through
the spout it has been found beneficial to include a venting means for directly venting
the head space of the holding tank to atmosphere during dumping. Venting lessens greatly
the tendency for belching or burping of discharging waste materials.
[0020] The disclosed embodiment comprises a vent valve 64 disposed on the top wall of the
holding tank somewhat opposite aperture 52. Details of the vent valve can be seen
in Figs. 2 and 3. The top wall of the holding tank is fashioned with an integral circular
boss 66 the lower portion of which projects into the interior of the holding tank.
The boss has a top wall 68 with a recess 69 formed centrally therein. Recess 69, at
the bottom, comprises a circular hole 70 concentric with the boss. Four arcuate vent
openings 72 are in wall 68 extending around recess 69 on a common circle. Openings
72 provide, via the interior bore of boss 66, venting of the tank interior to atmosphere.
A valving element 74 comprises a bifurcated shank 76 which fits closely within hole
70. A circular actuator button 78 is at the top of shank 76 and a helical spring 80
is disposed around shank 76 and between the bottom wall of recess 69 and actuator
button 78. The spring 80 biases the valving element 74 in the upward direction so
as to urge a suitable closure portion 82 against the lower circular edge of boss 66
so as to close the interior bore of the boss and hence the vent openings 72. The illustrated
construction for the closure portion comprises a rigid circular portion 84 which is
affixed to the lower end of shank 76 within the holding tank and which supports an
annular gasket 86 which seals against the lower circular edge of boss 66 when the
valve is closed.
[0021] The broken line position shown in Fig. 2 thus represents the closed position to which
the valving element which is normally spring biased. In this position the closure
portion prevents waste materials and vapors from passing through the vent openings
72. The solid line position illustrates the actuated position which isused during
dumping to vent the interior head space of the holding tank. It should be observed
that a stop 87 is provided on button 78 for limiting downward displacement so that
the button does not close off the vent openings when the valve is depressed. Thus,
actuation of the valve always allows air to pass through openings 72 into the holding
tank to prevent the creation of the partial vacuums which might give rise to belching
and burping during dumping.
[0022] It will be further observed that the location of the vent valve 64 is adjacent to
the operating handle 32. As can be appreciated from consideration of Fig. 9 the operating
handle also forms a portion of a grip which may be grasped by a person dumping the
holding tank. The configuration is such that the person's fingers fit conveniently.
onto the handle with the actuator button being poised to be pushed by his thumb to
the venting position. An upstanding lip 88 extends partially around (slightly more
than a semi-circle) the outside of the top wall 68 of boss 66. The upper edge of lip
88 is above button 78 when the valve is closed and it forms a protector against inadvertent
actuation of the valve. It also assists in preventing thumb slippage while the button
is being depressed. Thus function and convenience are greatly promoted by the arrangement.
[0023] Because the vent is located generally opposite the discharge spout it will inherently
be exposed to the head space of the tank during dumping, the tank being designed to
leave a head space when its liquid waste content is completely full. Accordingly,
liquid waste will not accidentally pass through the openings 72.
[0024] The particular constructional details of the seat and holding tank sections, the
vent valve and the spout may be accomplished with conventional materials and techniques.
In accordance with the typical manufacturing procedures the tanks sections are fabricated
from two injection molded halves having mating perimeters. The mating perimeters are
mated and sealed to form the enclosure. The spout may also advantageously be fabricated
from plastic and it may be manufactured by any suitable plastic forming technique
such as injection molding or blow molding. The vent valve components are also plastic,
with the exception of spring 80, and the element 86 being a suitable elastomeric material.
The assembly of the vent valve to the holding tank may be accomplished by fabricating
the valving element as separate pieces which are assembled together once they are
in the correct position. The illustrated construction of bifurcated shank 76 includes
catches at the distal end and the element 84 includes slots. The attachment involves
the end of shank 76 snapping onto element 84 at the inside the top wall of the tank
so that the catches lodge in the slots. Other alternative attachment procedures could
also be used.
[0025] The invention promotes conveniences in dumping because the point at which the waste
contents exit the spout is more remotely located from the person than would be the
case with prior types. The use of the venting valve promotes smoother discharge flow
and hence there is a significant reduction in an individual's concern about waste
contents splashing back. The construction is also advantageous in that the spout is
stored interiorly of the unit and does not protrude, except at dumping. The unit retains
overall compactness yet possesses improved function.
1. A portable toilet comprising a holding tank (14) characterized by a discharge spout
(36) on the exterior of the holding tank through which contents of the holding tank
are emptied and closure means (38) for opening and closing the discharge spout.
2. A portable toilet as claimed in claim 1, characterized in that said closure means
for opening and closing the discharge spout comprises a removable cap (38) at the
end of the spout (36) where the contents of the holding tank (14) are discharged from
the spout.
3. A portable toilet as claimed in claim 1 or 2, characterized in that the discharge
spout (36) is rotatably mounted in an aperture (52) in the wall (58) of the holding
tank (14) for rotation over a range of positions.
4. A portable toilet as claimed in claim 3, characterized in that the aperture (52)
is keyed (at 54) and the spout has one end correspondingly keyed (at 46) so as to
be fully insertable into and removable from the aperture only at one rotational position
of the spout and the keys (46,54) are constructed such that when the one end of the
spout is fully inserted into the aperture and the spout rotated to other than said
one position it cannot be separated from the holding tank.
5. A portable toilet as claimed in claim 4, characterized by a sealing gasket (50)
extending around the spout (36) immediately adjacent its key (46) and having a sealing
engagement with a corresponding portion of the aperture (52) for all rotational positions
over said range of positions.
6. A portable toilet as claimed in claim 4 or 5, characterized in that the holding
tank (14) comprises a top wall (58) and the aperture (52) is disposed at one corner
of the top wall of the holding tank, the holding tank also having side walls extending
away from said one corner at approximately a right angle, and in that the arrangement
of the keys of the aperture and of the spout is constructed such that the one end
of the spout can be fully inserted into the aperture with the spout overlying the
top wall and being generally parallel to one of said side walls and can be swung clear
of the holding tank on the order of three-quarters of a circle to another position
overlying the top wall and generally parallel to the other side wall.
7. A portable toilet as claimed in claim 6, characterized in that said closure means
for opening and closing the spout comprises a cap (38) on the discharge end of the
spout and the top wall (58) of the holding tank (14) comprises a recess (62) which
is engaged by a portion of the edge of the cap (38) to define a locator for the spout
establishing said another position.
8. A portable toilet as claimed in claim 7, characterized in that said another position
constitutes a storage position for the spout and wherein said portable toilet further
includes a seat section (12) disposed on the holding tank (14) with the two sections
defining a storage cavity within which the spout is housed when in the storage position.
9. A portable toilet as claimed in any preceding claim, characterized by venting means
(64) for venting the interior head space of the holding tank (14) when the contents
are being discharged via the spout (36).
10. A portable toilet as claimed in claim 9, characterized in that venting means comprises
a manually operated vent valve (64) which is spring (80) biased to a normally closed
position and includes an actuator(78) disposed adjacent a gripping point (32) of the
holding tank for actuation by a user who is emptying the holding tank.
11. A portable toilet as claimed in any preceding claim, characterized in that the
holding tank (14) comprises a top wall including an aperture (52) in said top wall
for mounting of the spout (36) and in which the spout is operable to a position pointing
away from the holding tank (14) for discharging the contents of the holding tank and
including manually operated vent valve means (64) which may be operated by the user
emptying the holding tank for venting the interior head space of the holding tank
during discharge.
12. A portable toilet as claimed in claim 11, characterized in that said aperture
(52) is disposed at a corner of the top wall and said vent valve means (64) is disposed
in the top wall at a location opposite that of said aperture.
13. A portable toilet comprising a holding tank section (14) and a seat section (12)
separably mounted on the holding tank section, said seat section comprising a bowl
(16) and said holding tank section comprising a valve (30) which is operable to allow
contents of the bowl to be deposited into the holding tank, characterized in that
a discharge spout (36) is provided via which the contents of the holding tank (14)
may be emptied, said seat and holding tank sections cooperatively defining between
their confronting surfaces a cavity with said spout (36) being disposed for storage
in the cavity and being positionable from its storage position to a discharge position
on the holding tank section for emptying the contents of the holding tank after the
seat section has been removed from the holding tank.
14. A portable toilet as claimed in claim 13 characterized in that normally closed
vent valve means (64) operable during emptying of the holding tank is provided for
venting the head space of the holding tank .
15. A portable toilet as claimed in claim 13, or 14 characterized in that the holding
tank section (14) comprises an aperture (52) with one end of the spout (36) being
disposed in said aperture and with the spout being rotatably mounted at the aperture
for positioning between the storage and discharge positions.