U.S. patent application number 12/026233 was filed with the patent office on 2008-08-07 for multi-piece tank for portable restrooms.
Invention is credited to Lance T. Hampel.
Application Number | 20080184471 12/026233 |
Document ID | / |
Family ID | 39674876 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080184471 |
Kind Code |
A1 |
Hampel; Lance T. |
August 7, 2008 |
Multi-Piece Tank for Portable Restrooms
Abstract
A holding tank for a portable restroom comprised of two parts, a
top portion and a bottom portion, is provided. The top portion fits
on the bottom portion to enclose an interior of the tank, and the
top portion defines a toilet opening. The top portion preferably
fits to the bottom portion with a tongue-and-groove joint. The
holding tank may include additional features, such as barbs
included between the top portion and the bottom portion that hold
the top portion to the bottom portion. In addition, the holding
tank may include a toilet bowl in the toilet opening, and the
toilet bowl may be flushed by water from an internal or external
fresh water vessel.
Inventors: |
Hampel; Lance T.; (Land
O'Lakes, WI) |
Correspondence
Address: |
QUARLES & BRADY LLP
411 E. WISCONSIN AVENUE, SUITE 2040
MILWAUKEE
WI
53202-4497
US
|
Family ID: |
39674876 |
Appl. No.: |
12/026233 |
Filed: |
February 5, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60888594 |
Feb 7, 2007 |
|
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60900500 |
Feb 9, 2007 |
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Current U.S.
Class: |
4/479 |
Current CPC
Class: |
Y02A 50/30 20180101;
Y02A 50/454 20180101; A47K 11/02 20130101 |
Class at
Publication: |
4/479 |
International
Class: |
A47K 11/02 20060101
A47K011/02 |
Claims
1. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, and the top
portion defining a toilet opening, the improvement wherein the top
portion fits to the bottom portion with a tongue-in-groove
joint.
2. A toilet holding tank as claimed in claim 1, wherein a groove of
the joint is defined by the top portion and a tongue of the joint
is defined by the bottom portion.
3. A toilet holding tank as claimed in claim 1, wherein the joint
is located around the entire perimeter of the tank.
4. A toilet holding tank as claimed in claim 1, further comprising
guide ribs extending downwardly from the top portion that assist
fitting the top portion to the bottom portion.
5. A toilet holding tank as claimed in claim 1, further comprising
barbs between the top portion and the bottom portion that hold the
top portion to the bottom portion, at least portions of the barbs
being molded integrally with at least one of the top portion and
the bottom portion.
6. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, and the top
portion defining a toilet opening, the improvement wherein there
are snap clips between the top portion and the bottom portion that
hold the top portion to the bottom portion, and at least portions
of the clips being molded integrally with at least one of the top
portion and the bottom portion.
7. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, the top
portion defining a toilet opening, and having a toilet bowl in the
toilet opening, the improvement wherein the holding tank has an
internal fresh water holding vessel for holding water to flush the
toilet bowl.
8. A toilet holding tank as claimed in claim 7, wherein the fresh
water holding vessel is connected by the top portion to one side of
a bowl of the toilet.
9. A toilet holding tank as claimed in claim 7, wherein the fresh
water holding vessel is fillable through a port in the top
portion.
10. A toilet holding tank as claimed in claim 9, wherein the port
is closable with a cover that is hinged to the top portion and has
an integrally molded barbed clip that holds the cover closed.
11. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, the top
portion defining a toilet opening, and having a toilet bowl in the
toilet opening, the improvement wherein the holding tank has an
external fresh water vessel for holding water to flush the toilet
bowl, the external fresh water vessel being supported on the top
portion to one side of the toilet opening, and the external fresh
water vessel being taller than it is wide.
12. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, the top
portion defining a toilet opening, and having a toilet bowl in the
toilet opening the improvement wherein the toilet bowl is flushable
with operation of a foot operated pump, the pump being held in a
housing and the housing having a label recess.
13. A toilet holding tank as claimed in claim 12, wherein a label
in the recess states "FLUSH".
14. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, and the top
portion defining a toilet opening, the improvement wherein at a
juncture between sidewalls of the bottom portion and the bottom
wall of the bottom portion, a skirt is included that supports the
tank on a support surface.
15. A toilet holding tank as claimed in claim 14, wherein the skirt
is interrupted.
16. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, and the top
portion defining a toilet opening, the improvement wherein the tank
contains an element that reduces the capacity of the tank to hold
waste.
17. A toilet holding tank as claimed in claim 16, wherein the
element is a tank.
18. A toilet holding tank as claimed in claim 16, wherein the
element is a bulkhead.
19. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, and the top
portion defining a toilet opening, the improvement wherein the top
portion has integrally molded ribs extending downwardly from a
lower surface that angle inwardly so as to guide the top portion
into engagement with the bottom portion upon assembly of the top
portion to the bottom portion.
20. A toilet holding tank as claimed in claim 19, wherein the ribs
support a plurality of top portions in a substantially vertical
stack when the top portions are stacked one on top of another.
21. In a toilet holding tank for a portable restroom, the tank
including a top portion and a bottom portion, the bottom portion
having a bottom wall, front, rear, left, and right sidewalls
extending up from the bottom wall and the top portion fitting on
the bottom portion to enclose an interior of the tank, and the top
portion defining a toilet opening, the improvement wherein the
toilet has a toilet bowl that is hinged to the top portion and
protrusions extend up from the top portion to engage the bowl
behind a rear edge of the bowl when the bowl is pivoted up to an
upright position, so as to help hold the bowl in the upright
position.
22. A toilet holding tank as claimed in claim 21, wherein the
protrusions help support a hinge pin of the bowl.
23. A toilet holding tank as claimed in claim 11, wherein the
external fresh water vessel includes a flush handle.
24. A toilet holding tank as claimed in claim 11, wherein the
external fresh water vessel has a leg extending downwardly to a
housing for a foot pump flush pedal.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional
application Nos. 60/888,594 filed Feb. 7, 2007 and 60/900,500,
filed Feb.9, 2007, the disclosures of which are hereby incorporated
by reference.
STATEMENT CONCERNING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] This invention relates to portable restrooms, and in
particular to toilet tanks for portable restrooms.
BACKGROUND OF THE INVENTION
[0004] The increased use of portable restrooms worldwide and the
substantial cost of transportation has created a need to reduce the
space required for shipping the unassembled components of a
portable restroom from the manufacturer to their customer,
predominately a portable restroom rental company, the military or
other governmental unit.
[0005] When shipping portable restrooms prior to assembly, many of
the components, like the wall panels and roofs nest very closely
and shipping is cost effective. Shipping the tank, traditionally
molded in one piece, is not cost effective. The tank usually
occupies the lower back half of a typical portable restroom,
provides the toilet system, and holds waste until the unit is
serviced by a pumper truck. These large hollow tanks do not nest
together and typically require as much as 40% of the total space
required for a shipment of the components of a load of portable
restrooms.
[0006] Tanks have been traditionally molded using low cost tools
adequate for low volume rotational molding, blow molding or
twinsheet thermoforming processes because of variations of style
and design. The three aforementioned processes used to produce
tanks all produce a completely enclosed hollow tank and share one
common limitation: the finished part will be comprised of a single
roughly uniform thickness. The shape of the outside surface of the
tank will be the shape of the inside surface. This occurs because
the processes have a mold surface that creates or shapes only the
outside surface. The material is forced to conform to the mold
surface by centrifugal force in the case of rotational molding, air
pressure in the case of blow molding, and air and vacuum pressure
in the case of twinsheet thermoforming.
[0007] Injection molding uses a mold that forms both the inside and
outside surfaces. It is this feature that gives the process an
advantage over the other processes. Most notable is that ribs,
bosses, and other intricate features can be made; additionally,
section thickness can be accurately maintained. However, injection
molded parts are traditionally molded with uniform wall thickness
to prevent warpage and sink marks that occur as a result of
material shrinkage due to cooling during and immediately following
the molding process.
[0008] In certain marketplaces, a flushing mechanism for the toilet
system is required. The liquid used for flushing can be either
recirculated waste fluids or fresh water. When fresh water is used,
an additional storage tank must be provided. Manufacturers have
positioned this freshwater tank in several different places within
or on a portable restroom all of which have some negative side
effect. The freshwater tank occupies an already crowded space if it
is inside the portable restroom.
[0009] Due to the aforementioned limitations of prior art designs,
a need exists for portable restroom components that require less
shipping volume and are created by more effective manufacturing
processes.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a holding tank for a
portable restroom comprised of two parts: a top portion and a
bottom portion. The top portion fits on the bottom portion to
enclose an interior of the tank, and the top portion defines a
toilet opening. The top portion preferably fits to the bottom
portion with a tongue-and-groove joint.
[0011] In another aspect of the invention, barbs are included
between the top portion and the bottom portion that hold the top
portion to the bottom portion. The barbs are preferably molded
integrally with the top portion or the bottom portion.
[0012] In another aspect of the invention, the holding tank may be
provided with an internal fresh water holding vessel for holding
water to flush a toilet bowl.
[0013] In another aspect of the invention, the holding tank may be
provided with an external fresh water holding vessel for holding
water to flush the toilet bowl. The external fresh water holding
vessel is preferably supported on the top portion to one side of
the toilet opening. The external fresh water holding vessel is also
preferably taller than it is wide.
[0014] In another aspect of the invention, the toilet bowl is
flushable by operation of a foot operated pump. The pump is
preferably held in a housing that has a label recess.
[0015] In another aspect of the invention, a skirt may be included
at a juncture between sidewalls of the bottom portion and bottom
wall of the bottom portion. The skirt supports the tank on a
support surface.
[0016] In another aspect of the invention, the holding tank may
include an element that reduces the capacity of the tank to hold
waste.
[0017] In another aspect of the invention, the top portion may
include integrally molded ribs extending downwardly from a lower
surface. The molded ribs angle inwardly so as to guide the top
portion into engagement with the bottom portion upon assembly of
the top portion to the bottom portion.
[0018] In yet another aspect of the invention, the toilet bowl may
be hinged to the top portion and protrusions extend up from the top
portion to engage the bowl behind a rear edge of the bowl when the
bowl is pivoted to an upright position. The protrusions help hold
the bowl in the upright position.
[0019] The foregoing and other objects and advantages of the
invention will appear in the detailed description which follows. In
the description, reference is made to the accompanying drawings
which illustrate a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an exploded perspective view of a toilet tank of
the invention spaced up off of a portable restroom skid on which
the tank would normally be supported with the toilet seat and lid
removed for clarity;
[0021] FIG. 2 is a bottom perspective view of a bottom or tank
portion of the toilet tank;
[0022] FIG. 3 is a view like FIG. 1 but with the tank sitting on
the skid and sectioned;
[0023] FIG. 4 is a sectional perspective view of the bottom portion
of the tank;
[0024] FIG. 5 is a sectional perspective view of the bottom portion
of the tank;
[0025] FIG. 6 is a sectional perspective view of the of the toilet
tank top and bottom assembled together;
[0026] FIG. 7 is a detail sectional perspective view of the upper
rear portion of FIG. 6;
[0027] FIG. 8 is a sectional perspective view through the toilet
tank top and bottom showing one embodiment of a clip to hold the
top and bottom together;
[0028] FIG. 9 is a detail sectional perspective view of the clip of
FIG. 9;
[0029] FIG. 10 is a perspective view of the top upside-down;
[0030] FIG. 11 is a view of a portion of the top and bottom
illustrating how the ribs guide assembly;
[0031] FIG. 11a is a detail view of the ribs of FIG. 11;
[0032] FIG. 12 is a sectional perspective view of the tops showing
how the ribs of the tops assist stacking;
[0033] FIG. 13 is a perspective view of the top with a bowl
assembled to it;
[0034] FIG. 14 is a view like FIG. 13 with the bowl tilted up;
[0035] FIG. 15 is a detail fragmentary view of the hinge support
portions of FIG. 14;
[0036] FIG. 16 is a perspective view of a foot pump flushable
toilet tank of the invention supported on a portable restroom
skid;
[0037] FIG. 16a is a detail sectional perspective view of the foot
pump of FIG. 16;
[0038] FIG. 17 is a perspective view of the foot pump flushable
toilet tank of FIG. 16 with an optional hinged cap;
[0039] FIG. 18 is a perspective view of a foot pump flushable
toilet tank of FIG. 16 showing a tube connecting the foot pump and
the tank;
[0040] FIG. 19 is a top view of the inside of the toilet tank
bottom showing a filter/strainer and tubing;
[0041] FIG. 19a is a detail view of the filter/strainer and tubing
of FIG. 19;
[0042] FIG. 20 is a sectional perspective view of the toilet tank
bottom showing the filter/strainer and tubing of FIG. 19;
[0043] FIG. 20a is a detail view of the filter/strainer and tubing
of FIG. 20;
[0044] FIG. 21 is a sectional view through the toilet tank showing
an internal fresh water storage vessel;
[0045] FIG. 22 is a fragmentary exploded perspective view
illustrating how the internal fresh water vessel is fastened to the
top of the toilet tank;
[0046] FIG. 22a is a detail perspective view of the fresh water
tank of FIG. 22;
[0047] FIG. 23 is a fragmentary exploded perspective view of the
top and the internal fresh water vessel of FIG. 22;
[0048] FIG. 24 is a fragmentary perspective view of the freshwater
fill port cover of FIG. 17 open;
[0049] FIG. 24a is a detail perspective view of the freshwater fill
port cover of FIG. 24;
[0050] FIG. 25 is a view like FIG. 16 but with an alternative
freshwater flush tank that is external to the toilet tank;
[0051] FIG. 26 is a view of a tank bottom with a reduced capacity
tank installed;
[0052] FIG. 27 is a view like FIG. 26 but with the reduced capacity
tank removed;
[0053] FIG. 28 is a view of a tank bottom with a bulkhead installed
for reducing capacity;
[0054] FIG. 29 is a view like FIG. 26 from a different angle;
[0055] FIG. 30 is a perspective view of the freshwater tank of
FIGS. 21-24;
[0056] FIG. 31 is a sectional view of the tank of FIG. 30;
[0057] FIG. 32 is a detail sectional view of FIG. 31; and
[0058] FIG. 33 is a perspective view of an alternate embodiment of
an external fresh water tank shown assembled to a toilet tank.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0059] A multi-piece portable restroom toilet tank according the
present invention is to be located inside a portable restroom. The
walls of the portable restroom are shown in several of the
accompanying figures. However, the walls are not shown in most
figures to more clearly illustrate the multi-piece portable
restroom toilet tank.
[0060] Referring to FIG. 1, the multi-piece portable restroom
toilet tank 10 of the present invention is a generally rectangular
three-dimensional tank with a toilet system integral to a top
portion 11 of the tank 10. The top portion 11 of the tank 10
includes an elevated surface 15, a recessed surface 17, and an
elevated toilet surface 19. The elevated surface 15 and the
recessed surface 17 are sloped downward to prevent pooling of
liquids. The elevated toilet surface 19 is raised above the
recessed surface 17 to provide clearance for a user's clothing and
to provide a place for a toilet seat to mount. The elevated toilet
surface 19 is generally arcuate and preferably extends slightly
from a front edge of the top portion 11. The top portion 11 also
includes an opening 18 for a vent tube (not shown) and an opening
20 for a urinal (not shown). If the unit is used without the
urinal, the opening 20 can be provided with a snap cover (not
shown).
[0061] The top portion 11 and the other components discussed below
are light weight. This is advantageous since it simplifies loading
and unloading the components from transport equipment. The top
portion 11 of the tank 10 is strong enough to support a 350-pound
person. To accomplish this and keep the top portion 11 lightweight,
the component is made with a minimal thickness, but it is
reinforced with substantially perpendicular integral ribs 52, as
shown in FIG. 10, to increase its strength. The ribs 52 extend from
a lower surface of the top portion 11. Where the ribs 52 terminate
near the perimeter of the top portion 11 they extend downwards
(toward the bottom of the tank) beyond the depth of the material at
the perimeter at an acute angle towards the center of the tank 10,
relative to the side of the tank 10. Therefore, the ribs 52 act as
a guide to ease assembly of the top portion 11 and a bottom portion
12 of the tank 10, as shown in FIGS. 11 and l a. The ribs 52 also
aid in nesting the parts when they are shipped unassembled. This
aspect will be discussed in further detail below.
[0062] Referring to FIGS. 1 and 2, the tank 10 also includes the
bottom portion 12 that has a bottom wall and front, rear, left, and
right sidewalls extending up from the bottom wall. The bottom
portion 12 is shaped such that when the unit is pumped the waste
collects in a pyramid-shaped sump 13 located directly below a
toilet opening 14 defined by the elevated surface 19 of the top
portion 11. The bottom portion 12 includes a protruding surface 16
located below the section of the elevated toilet surface 19 that
extends from the front edge of the top portion 11. The surfaces 21
adjacent the protruding surface 16 provide clearance for the user's
legs and clothing. The bottom portion 12 also includes a boss 23
located near the sump 13 that will be discussed in further detail
below.
[0063] Referring to FIGS. 3-5, the bottom portion 12 is also
designed such that it sits on the edges of a slot of a portable
restroom base and supports the weight of the user and the contents
of the tank. The outer surfaces of the top portion 11 and the
bottom portion 12 are smooth for easy cleaning. The bottom portion
12 of tank 10 does not have any level flat areas near the edges of
the slot of the portable restroom base. This prevents solid matter
from collecting on the surfaces near the edges of the slot of the
portable restroom base. Therefore the support surfaces, where the
tank meets the portable restroom base, are sloped towards the
center of the tank 10, specifically toward the low spot 13. To fill
the external gap created where the bottom portion 12 extends
forward of the portable restroom base slot, an interrupted skirt or
flange 60 is provided along the front and the back that extends
downward from the area of the corners where the front and rear
panels meet the bottom wall, as shown in FIGS. 2-5. Additionally,
this skirt 60 distributes the weight of the tank 10, its contents,
and a user in a proper vertical direction to the top surface of the
portable restroom base. As best shown in FIG. 5, the skirt 60 has
outer walls 61 that join seamlessly with the outer walls of the
tank and have generally vertical reinforcing ribs 63.
[0064] Referring to FIGS. 6 and 7, the tank 10 includes components
to connect the top portion 11 and the bottom portion 12.
Specifically, the top portion 11 includes a two tined fork 36, or
groove, and the bottom portion 12 includes a single blade 38, or
tongue, that fits between the tines of the two tined fork 36. The
seam 37, or tongue-in-groove joint, formed by the fork 36 and the
blade 38 is located around the entire perimeter of the tank 10
where the portions 11 and 12 meet. The seam 37 enables the top
portion 11 and the bottom portion 12 to be sealed or bonded
together, using a suitable sealant or caulk for example, providing
a leak-free joint. Other types of seams may disadvantageously leak
before the tank is filled to capacity. In addition, differences of
expansion and contraction of the top portion 11 and the bottom
portion 12 could cause warping of sections of the tank 10 if the
blade 38 of the bottom portion 12 is not trapped in between the
tines of the fork 36. Lastly, the seam 37 design provides
additional strength to keep the top portion 11 and the bottom
portion 12 from separating if the tank is full and the restroom is
impacted or tipped.
[0065] Referring to FIGS. 8-11, a fastening method is required
between the top portion 11 and the bottom portion 12 because of the
aforementioned hydraulic and user pressure exerted on the seam 37.
A plurality of snap clips 42 located at different points on the
seam 37 are incorporated in this design that include barbs 46,
protruding from the blade 38 on the bottom portion 12, as shown in
FIG. 9. The barbs 46 engage openings 50 in the mating surface of
the top portion 11 to hold the two components together.
Alternatively, the barbs 46 may be located on the top portion 11
and the openings 50 may be located on the bottom portion 12. The
design of the clips 42 is such that they will engage automatically
while assembling the top portion 11 to the bottom portion 12 of the
tank 10. If the tank 10 needs to be disassembled, the clips 42 can
be disengaged by placing a bladed tool, like a screwdriver, into
the seam 37 where the clips are located, allowing the portions 11
and 12 of the tank 10 to then be pulled apart. If it is desirable
to assemble the tank 10 such that it can easily be disassembled,
the barbs 46 of the respective clips 42 can be removed by cutting
all or some of them off.
[0066] Alternatively, the top portion 11 and the bottom portion 12
may be fastened by using standard fasteners at the seam 37, such as
rivets. In addition, a combination of rivets and clips 42 may be
used, such as using rivets along the front edge of the seam 37 and
using clips 42 along all other edges of the seam 37.
[0067] A standard tank, commonly known as a drop tank, has no
flushing apparatus. It has only a toilet seat and a cover installed
on top of the elevated toilet surface 19 of the top portion 11 of
the tank 10. Referring to FIGS. 13-17, a bowl 30 and a cover 31 may
be provided with the tank 10. The primary reason to include the
bowl 30 is to hide the contents of the tank. To adequately hide the
contents of the tank, the outlet of the bowl is either closed off
by a counterweighted mechanical flap or positioned to obscure the
view. The opening can be aimed towards the back wall or the front
wall of the tank 10. Preferably the bowl 30 includes an opening
aimed towards the front wall of the tank 10. This configuration is
preferred because it is most effective at obscuring the view and
because of repair problems with the mechanical flap. All three of
the aforementioned configurations of the bowl 30 are presently in
use in the prior art.
[0068] Referring to FIGS. 14 and 15, the bowl 30 is pivotable to
provide access to pump waste out of the tank 10 and maintain the
system. Two protrusions 66, one at each end of a hinge pin 68 and
supporting the ends of the hinge pin 68, are provided to maintain
an upright position of the bowl 30 while pumping waste out of the
tank 10. The protrusions 66 engage behind a flange 70 of the bowl
30 when the bowl 30 is in the upright position. The ramp like shape
of the protrusions 66 allows the bowl 30 to be returned to a closed
position with a simple one-handed motion.
[0069] The bowl is easily soiled because of its shape, and
therefore a flushing system is preferably included. The tank 10 is
configured to accommodate either a recirculating or a fresh water
flushing system. The tank 10 can also be converted in the field by
interchanging several parts but the pump and the bowl are provided
in either system. Most current designs include components and
features such as a bowl, piping and nozzle, pump, filter/strainer
or freshwater storage vessel, pumping, filling, and maintenance
access.
[0070] When a flushing system is used, a toilet bowl, flushing
apparatus and liquid source are provided. All flushing systems
include, in addition to the bowl, a pump, either hand or foot
operated, a nozzle or manifold to distribute the liquid around the
bowl, and tubing to transport the liquid between the source, the
pump, and the bowl. If the flushing system is a recirculating
system, it also includes a filter/strainer and a tube connected to
the pump that is placed in the bottom of the tank to provide the
source of the liquid for the system. Such recirculating systems are
well known in the art. If the flushing system is a fresh water
system, a source for the fresh water is provided with tubing
connecting it to the pump, as described below. The pump may be
either a hand pump or a foot pump. Both types of pumps may be used
since each has recognized disadvantages. A foot pump may not be
obvious to a user, and some users may not want to touch a hand
pump, thereby leaving the toilet unflushed. The tank provided in
the present invention can accommodate either type of pump without
modification of the tank itself.
[0071] Referring to FIGS. 16-17, to overcome the previously
mentioned shortcoming of the foot pump, the fact that it is not
obvious to the user, the present invention provides a labeled
housing 74 to enclose and facilitate attaching the foot pump 76 to
the portable restroom. The foot pump 76 may be any type of simple
pump known in the art capable of delivering liquid to the bowl 30.
The housing 74 includes a bottom 78 and a top 80. The bottom 78
provides adequate space for attaching the housing 74 to the
portable restroom base and positioning the foot pump 76. The top 80
overlaps the bottom 78 and has an opening for the pump diaphragm
actuator. Preferably the housing 74 also has a relatively large
recessed area 82 where a brightly colored label 83 that reads
"FLUSH" or its translation in a different language is positioned.
The recess 82 is provided to protect the edges of the label 83.
[0072] Referring to FIGS. 18-21, tubing 85 is provided to connect
the various components of the flushing system. Specifically, the
tubing 85 connects to the foot pump 76, passes through a hole 77 in
the corner of the bottom portion 12, and connects to a
filter/strainer 87 if the unit is configured for recirculated
flushing. Additional tubing (not shown) is provided to connect the
foot pump 76 and the bowl 30 and to provide liquid to the bowl 30.
The tubing 85 is preferably fixed to the bottom of the bottom
portion 12 by a bracket 79. The bracket 79 is fixed to the bottom
portion 12 by a fastener (not shown) that is accommodated in the
boss 23 (FIG. 2). Alternatively, standoffs (not shown) protruding
upwards on the bottom of the bottom portion 12 of the tank 10 may
be provided. Both the bracket 79 or the standoffs keep the
filter/strainer 87 in a proper position--in the sump. The
filter/strainer 87 is in this position for adequate coverage when
the unit is first placed in service and there is only a small
pre-charge of water and chemical in the unit. The standoffs can
also be used to position and/or support a bulkhead as described
below or to hold the tubing 85 routed in the interior of the tank
10.
[0073] Like prior art designs, the bowl 30 protrudes nearly half
way to the bottom of the tank 10. Therefore, the waste storage
capacity of the tank 10 is approximately halved. Once waste reaches
the bottom opening in the bowl 30 its effectiveness in hiding the
waste is negated, although there is no danger to the system if this
happens. As illustrated in FIGS. 21-24, the preferred embodiment
utilizes the empty space left in the upper portion of the tank 10
for an internal fresh water storage vessel 90. The internal fresh
water vessel 90 is shown separate from the tank 10 in FIGS. 30-32.
The internal fresh water vessel 90 includes an top section 93 and a
bottom section 95. The top section 93 and the bottom section 95 may
be connected by any suitable method, such as ultrasonic welding or
caulking a flange section 99. The sections 93 and 95 should be
designed such that they do not interfere with the top portion 11 or
the bottom portion 12 of the tank 10. For example, the top section
93 includes multiple recessed areas to avoid the ribs 52 on the top
portion 11. In addition, the top section 93 of the internal fresh
water vessel 90 includes a hole 97 that permits access to the
interior of the internal fresh water vessel 90. The surface that
defines the hole 97 is slightly recessed to create a space between
the internal fresh water vessel 90 and the top portion 11. This
permits tubing (not shown) from the foot pump 76 to pass through
the hole 97 and into the internal fresh water vessel 90. Three
features are required to utilize the internal fresh water vessel
90:
[0074] 1) The tank 10 must be two-piece to enable installing the
internal fresh water vessel 90;
[0075] 2) Components must be provided to mount the internal fresh
water vessel 90 that are capable of supporting the additional
weight. As shown in FIGS. 22-23, a series of bosses 91 on the
underside of the top portion 11, some shown in FIG. 10, enable
threaded screw-type fasteners 94 to pass through holes 92 in the
flange of the custom fitted internal fresh water vessel 90 and
engage the bosses 91; and
[0076] 3) Access to the interior space of the internal fresh water
vessel 90 must be provided. Referring to FIGS. 24 and 24a, a port
100 may be provided in the top portion 11 with a hinged cover 102
and latching mechanism 104 for filling the internal fresh water
vessel 90. The hinge feature of the cover 102 is comprised of two
bent tabs 106 that are inserted through slots in the top portion 11
before placing the tank 10 in the portable restroom. Once the cover
102 is installed in the portable restroom it is not easily removed
because of its close proximity to a wall. The latching mechanism of
the cover 102 includes a barbed clip 108 that deflects over a ledge
while closing. The ledge is formed on a tab 110 on the top portion
11 of the tank 10. The barbed clip 108 engages the ledge on the tab
110 to hold the cover 102 closed. A rib 112 around the port 100
protrudes from the top portion 11 next to and inside of the cover
102. The rib 112 is recessed behind the barbed clip 108 to require
a tool to force the barbed clip 108 back into the recess to open
the cover 102. The shape and position of this port 100 and cover
102 also provides a positioning and interlocking function for an
external fresh water vessel, if used.
[0077] Referring to FIG. 25, an alternative position to mount a
fresh water storage tank that encroaches less useable restroom
space is to place it on top of the top portion 11 off to one side
so it does not crowd the user. The external fresh water vessel 120
is designed taller than it is wide and its front-to-back dimension
approximates that of the waste tank. The external fresh water
vessel 120 is designed as such so that it holds the required amount
of fresh water.
[0078] Referring to FIG. 33, which discloses an alternate
embodiment of an external fresh water storage tank 140 for the tank
10, this configuration enables the placement of a handle 142 of a
hand-operated flush pump 144 to be placed up away from the bowl.
The handle 142 is supported by the tank 140 in a position where the
user would be more familiar and comfortable with using the pump
because the pump is similar to a conventional modern flush toilet
valve. With the hand pump configuration, the port 100 is suitable
for tubing (not shown) that passes into the storage tank.
Additionally this design allows for the external fresh water tank
140 to be molded with a leg 146 that extends down to a foot pump
housing 148 to provide additional support, capacity, and a location
for the connections and tubing if the foot pump is substituted for
the hand pump. A toilet tissue dispenser 150 could also be built
into the tank 140 as illustrated. Also, with an external fresh
water vessel 120 or 140, the static pressure of the water in the
vessel 120 or 140 can be used to flush the bowl.
[0079] Some operators use tanks with reduced capacity as requested
by their customers. As such, a secondary smaller tank 130 can
preferably be inserted inside the bottom portion 12 to reduce its
capacity, as shown in FIGS. 26 and 27. An alternative is to place a
bulkhead divider 132 into the bottom portion 12 to reduce its
capacity as illustrated in FIGS. 28 and 29.
[0080] An advantage of this design is nestability to facilitate
greater unit shipping density and consequently lower shipping
costs. Most tanks known to those skilled in the art are one-piece
hollow units that require a relatively large shipping volume. When
a tank is molded in two halves, the parts can be designed so that
like parts, top portions 11 or bottom portions 12, will nest to
increase shipping density. The design should incorporate integral
spacers to keep the nested parts from jamming together. The bottom
portions 12 of the tanks 10 of the present design nest within 2
inches of each other and have several unique features that keep the
parts from jamming. Specifically, the bottom portion 12 includes a
plurality of anti-jam sections 134 as shown in FIGS. 3 and 8. The
anti-jam section 134 are preferably located at various positions
along the perimeter of the connection between the bottom wall and
the side walls of the bottom portion 12. The anti-jam sections 134
prevent a stack of bottom portions 12 from moving closer to each
other and reorienting relative to one another. In addition, the
interrupted skirt or flange 60 may also prevent a stack of bottom
portions 12 to move relative to one another.
[0081] The ribs 52 of the top portion 11 are also integral spacers
for stacking multiple components. As shown in FIG. 12, the ribs 52
extend downwards from the surface they are integral with and
conform with the top surface of a like part below it in a stack. As
such, a set of top panels 11 may be stacked on top of one another
in the same orientation. The ribs spaced around the perimeter of
the part extend the same distance and are taller than any other
ribs. This permits a top panel 11 to sit horizontally when placed
on a skid.
[0082] The components of the present invention are preferably made
using a variation of the plastic injection molding process. This
process is called structural web or gas assist injection molding.
This injection molding variation is well known in the prior art.
The gas assist injection molding process is as follows. The molds
are first closed, and plastic resin is injected through multiple
nozzles in the back of the mold. Gas, usually nitrogen, is then
injected through the same nozzle. The gas passes through the hot
center portion of the plastic and follows defined channels in the
plastic part. After the part adequately cools, the mold opens, and
the part is ejected.
[0083] Gas assist injection molding differs from standard injection
molding in several ways that are advantageous to forming the
components of the present invention. For example, the material is
forced to the mold surfaces by gas pressure rather than injection
pressure. The result of this is lower tooling cost compared to
standard injection molding. This is possible because gas assist
injection molds can be made from aluminum rather than steel since
they do not have to withstand the relatively high pressures of
standard injection molds. Additionally, the distance from the
inside surface to the outside surface of the part, the wall
thickness, can vary with gas assist injection molding. With this
process, if there is a greater distance between the opposing
surfaces in one section of the part than another, the area with the
greater distance will hollow out as a result of the injected gas
and the part can be made free of warp and sink marks.
[0084] As mentioned above, the present invention may include
various types of flushing options. Several components for the
various types of flushing options may be created in each gas assist
injection molding cycle. This capability may offset the cost of
details incorporated into the molded components, such as the
aforementioned ribs and standoffs.
[0085] A preferred embodiment of the invention has been described
in considerable detail. Many modifications and variations to the
preferred embodiment described will be apparent to a person of
ordinary skill in the art. Therefore, the invention should not be
limited to the embodiment described.
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