Note: Descriptions are shown in the official language in which they were submitted.
CA 02450304 2003-12-10
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Title: CHECK VALVE FLOOR DRAIN
TECHNICAL FIELD
The invention relates to drains for building floors, basements, exterior paved
areas, and the
like. The invention provides floor drain asseinblies and check valves
providing improved drainage
performance and minimized backflow, particularly where drainage is an
irregular occurrence.
BACKGROUND OF THE INVENTION
U-shaped or "gooseneck" traps have long been used in the plumbing industry to
prevent
backflow of harmful or annoying sewer or pipe gasses into buildings while
permitting drainage of
unwanted water from floors and other horizontal surfaces. Such traps operate
by leaving a small
quantity of fluid within the lower portion of a U-shaped trap section to act
as a gas barrier. In many
applications, however, particularly where access is difficult or where
drainage is infrequent, it is
disadvantageous to use such drains. Fluid may evaporate from the trap,
permitting free flow of
obnoxious gases through the drain; insects may breed in the fluid, or in some
instances the fluids
may harden so as to actually block or restrict flow through the drain. Such
conventional drains are
also relatively difficult and expensive to install. In addition to floor drain
applications, these
problems are also common to other areas of fluid control, wherever fluid
drainage is an occasional
problem.
One solution to these problems has been the use of trap primers, which operate
to ensure
that a minimum level of fluid is left in the drain to act as a trap for gasses
which acculnulate within
drains. Trap primers are usually difficult and expensive to install, and
require maintenance and
constant monitoring to ensure their functionality.
Outside the floor drain environment, the use of check valves has been
suggested. As
demonstrated herein, check valves can be efficient both in facilitating
draining operations and in
trapping drain-pipe gasses and preventing backflow. Heretofore, however, no
one has suggested
CA 02450304 2006-10-19
placing simple and efficient check valves in floor drains, either alone or in
combination or in series with other types of valves.
DISCLOSURE OF THE INVENTION
In accordance with one aspect of the invention, there is provided a check
valve floor drain assembly for draining liquid from a draining surface into a
drain conduit. The floor drain assembly includes a drain basin having a drain
inlet for liquid draining from the draining surface and an outlet for
attachment
to the drain conduit. The floor drain assembly includes a check valve disposed
within the drain basin, the check valve adapted to permit substantially
unrestricted flow of liquid from the drain inlet to the drain conduit, and to
prevent backflow of gasses located within the drain conduit to the drain
inlet.
The floor drain assembly also includes the check valve being constructed
entirely from a substantially flexible elastomeric material with memory
properties that allow the check valve to open for fluid passage and then
return
to its original shape; whereby the check valve allows liquid to drain from the
draining surface and achieves a seal to prevent backflow of gases from the
drain conduit after liquid has drained.
In accordance with another aspect of the invention, there is provided a valve
assembly for use in substantially vertically draining drain surfaces. The
valve
assembly includes a support structure adapted for disposition within a drain
basin, the support structure adapted to support a plurality of check valves.
The valve assembly also includes at least two of the check valves removably
or interchangeably disposed within the support structure and placed in series
so as to form between a first valve and a second valve a chamber, the check
valves adapted to permit drainage of a liquid from the drain inlet and from
the
chamber, and to prevent backflow of gasses located within the drain conduit
and the chamber to the inlet, whereby a redundant seal is achieved to prevent
backflow of gases in the event one of the serial valves fails to close.
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In accordance with another aspect of the invention, there is provided a drain
assembly for use in substantially vertical drainage of drain surfaces. The
assembly includes a drain basin having an inlet and an outlet, the outlet
adapted for attachment of a drain conduit. The drain basin further includes a
plurality of check valves disposed within the drain basin, the
plurality of check valves comprising at least one check valve placed in series
with a second check valve so as to form a chamber between the first valve
and the second valve, the check valves adapted to permit drainage of a liquid
from the drain inlet and from the chamber, and to prevent backflow of gasses
located within the drain conduit and the chamber to the inlet, whereby a
redundant seal is achieved to prevent backflow of gases in the event one of
the serial valves fails to close.
In accordance with another aspect of the invention, there is provided a check
valve for a floor drain. The check valve adapted for disposition within a
floor
drain includes a drain sealing surface located proximate to an inlet to the
floor
drain and a stop adapted for sealing engagement of the drain sealing surface,
the stop further adapted to provide substantial flow of liquid in the open
position around the periphery of the stop. The check valve also includes a
means adapted to urge the stop into sealing engagement with the drain
sealing surface, the means adapted to permit disengagement of the stop from
the sealing surface as liquid enters the drain, whereby free flowing drainage
of
liquid is permitted through the floor drain, and backflow of gasses from the
floor drain is prevented after liquid has drained.
In accordance with another aspect of the invention, there is provided a side
port floor drain apparatus for admitting liquid from a draining surface into a
drain conduit and for preventing discharge of waste gas from the drain conduit
into the atmosphere in response to a higher pressure in the drain conduit than
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at the draining surface. The floor drain apparatus includes a housing having
circumferential walls with an exterior surface and an interior surface, an
open
bore extending throughout, a first section, a second inwardly tapered
midsection, a third section designed for connection with the drain conduit,
and
a cover joined over the first section, forming a chamber adapted for
connection with the drain conduit. The floor drain apparatus includes a drain
port through the walls of the housing having a non-horizontal drain sealing
surface on the interior surface, the drain port creating a path for liquid
from the
exterior surface into the drain conduit. The floor drain apparatus also
includes
a stop disposed on the interior surface, located between the non-horizontal
drain sealing surface and the drain conduit, configured to sealingly engage
the drain sealing surface and movably operate within the chamber, and further
configured to admit liquid proximate to the exterior surface into the chamber
and into the drain conduit and to prevent discharge of waste gas from the
drain conduit into the atmosphere in response to a higher pressure in the
drain conduit than at the draining surface.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic plan view of a preferred embodiment of a drain
assembly according to the invention ;
Figure 2 is a schematic cutaway cross section view of Figure 1
Figure 3 is a schematic cutaway side view of another preferred
embodiment of a valve assembly according to the invention;
Figure 4 is a schematic perspective view of another preferred
embodiment of a check valve according to the invention;
Figure 5 is a schematic cross-sectional view of the apparatus of Fig. 4.
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Figure 6 is a schematic cross-sectional view of the apparatus of Fig. 4
with the diaphragm opened by presence of a liquid;
Figure 7 is a schematic cross-sectional view of an alternative preferred
embodiment of a check valve floor drain according to the
invention;
Figure 8 is a schematic perspective partial section view of another
alternative preferred embodiment of a check valve floor drain
according to the invention; and
Figure 9 is a schematic cross-sectional view of yet another alternative
preferred embodiment of a check valve floor drain according to
the invention.
BEST MODE OF CARRYING OUT THE INVENTION
Turning now to the drawings, the invention will be described in a preferred
embodiment by reference to the numerals of the drawing figures wherein like
numbers indicate like parts.
The invention pertains to an apparatus for allowing substantially unrestricted
flow from any draining surface while preventing backflow from the drain
conduit. References in the specifications and claims to a draining surface, a
floor, or the like, mean any surface requiring a drain. The surface being
drained could be a roof, a compartment, a sink, a counter top, a floor, an on-
grade surface, or a below-grade surface. The surface could be on land or
onboard a ship.
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Specific references to a type surface being drained are to illustrate the
invention and not limit its specifications or claims.
Figure 1 shows a schematic plan view of a preferred embodiment of a drain
assembly according to the invention. Figure 2 shows a schematic cross
section view of the drain assembly
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of Figure 1. Drain assembly 100 is installed in drain surface 10 so that water
or other liquids
present on and above the drain surface may drain freely through the drain
assembly wllile gasses
present beneath the drain remain trapped in place. Drain assembly 100
comprises drain basin 101,
which includes inlet 102 and outlet 103; outlet 103 is attached to drain
conduit 110. A check valve
assembly 120 is disposed with two check valves 125 and 126 being placed in
series so as to form
chamber 130 within the drain basin. By virtue of their substantially vertical
orientation and their
design opening or actuating pressures, check valve assembly 120 is adapted to
permit drainage of
a liquid from said drain inlet and from said chamber, and to prevent backflow
of liquids and / or
gasses located within said drain conduit and said chamber to said inlet (as
shown by arrows 150
in Figure 3). Thus the drain assembly acts as both a drain valve and a trap,
without the difficulties
and expense of installing prior art p-shaped drain traps, and without the
necessity and expense for
employing a trap primer.
In preferred embodiments ofthe invention, the substantially vertical
orientation ofthe drain
assembly and the selection and use of valves having appropriate actuation or
opening pressures,
prevents substantial amounts of liquid from building up witliin chamber the
chamber 130 as liquid
drains through the assembly.
Preferably, valves are chosen such that their actuation or opening pressures
permit air or
other liquids to bleed through the drain assembly in order to relieve any
vacuum which may build
up in the drain conduit.
The use of more than one check valve, with the valves disposed' in series and
adapted to
operate independently of each other, helps to ensure proper functioning of the
drain, particularly
in case foreign matter intercedes between the check valve itself and any
surrounding structure in
such manner as to prevent the valve from closing properly or completely. This
is particularly
useful in ensuring that unwanted gasses remain trapped within the drain
conduit, and are not
permitted to escape into the atmosphere above the drain; and in preventing
back flow througli the
drain due to floods, etc. This structure also precludes access by insects to
liquids in the drain.
A particularly useful optional feature of preferred embodiments of the drain
assembly
according to the invention is the placement or mounting of the check valves in
a removable
stiltcture to facilitate cleaning, repair, replacement, or other maintenance
of the valves. For
exainple, in the embodiment shown in Figures 1 and 2 check valve assembly 120
is mounted in
frame 140, which rests upon shoulder 142 in the drain basin. Proper
functioning of the drain is
aided, in the embodiment shown, by the use of optional sealing ring 143, which
is in place between
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the frame 140 and drain basin 101. Frame 140 is removable from the drain
assembly by means of
ring 141, or any other structure suitable or mechanism suitable for the
purpose.
As indicated above, check valves used with the invention may be of any
suitable type. In
the einbodiment shown in Figures 1 and 2 flapper valves 121 are used. Flapper
valves 121
comprise flexible valve portions 123 and optional substantially rigid back
plates 122. The
construction and operation of flapper valves, with or without back plates, is
well understood by
those having ordinary skill in the art, and will not trouble the designer of
systems of the type
described herein.
Figure 3 is a schematic cutaway side view of a prefeiTed embodiment of a valve
assembly
190 according to the invention. In the embodiment shown, first check valve
assembly 120 and
second check valve assembly 120a each comprise two spring-biased valves 128
and 128a
comprising a valve plate 129 and 129a and a spring 127 and 127a. As will be
readily appreciated
by the artisan of ordinary skill, valves 128 and 128a open under the action of
a relatively higher
pressure above the drain and a relatively lower pressure beneath the drain. It
is to be noted that
valve assembly 190 is inserted directly into drain basin 101, which may
consist of, for example,
an open end of a drain conduit 103. It should also be noted that chamber 130
may comprise either
a single annular (or arbitrarily shaped) chamber or a set of multiple chambers
between different
groups of check valves.
Figure 4 is a schematic perspective view of another preferred embodiment of a
check valve
according to the invention. Figures 5 and 6 are schematic cross-sectional
views of the device of
Fig. 4. Check valve 100 is in place in floor drain 10. Check valve 200
comprises diaphragm 203
adapted for sealing engagement of drain sealing surface 201, which when check
valve 100 is
installed in a floor drain is located proximate inlet 14 of drain 10, such
that when diaphragm 203
is sealingly engaged with sealing surface 201, a liquid tight seal is produced
between the drain
basin 11 or the exterior of the drain and drain conduit 110 attached to the
drain. Thus, gasses
trapped within the interior of the drain or within drain conduit I 10 are
prevented from escaping
from the drain.
Most typically, sealing surface 201 is formed by a circumferential rim or
other surface
disposed about an outlet to the drain conduit, or by a part of a removable
housing such as optional
housing 210 for check valve 100, which is provided for ease installation or
removal. In the
embodiment shown in Figures 1 - 3, sealing surface 101 is a part of housing
110, which together
with optional gasket 112 serves to form a seal between diaphragm 203 and the
wall of drain 110.
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In the embodiment shown in Figures 1- 3, flexible diaphragm 203 is formed to
engage
sealing surface 201. As shown in Figures 1 and 3, diaphragm 203 has sufficient
flexibility to flex
under action of a liquid (represented by arrows 17) as it enters drain basin
11, and thus to allow
drainage of the liquid, and to return substantially to its original, unflexed
condition, so that sealing
between the diaphragm and the drain sealing surface is restored as the liquid
drains. In preferred
einbodiments of this aspect of the invention diapliragm 203 is adapted to flex
under the action of
a preselected head pressure within said drain. This may be accomplished in any
number of ways,
most of which will occur to those of ordinary skill in the art once they have
been exposed to the
material herein. For example, diaphragm 203 may be made of a suitable uniform
thickness such
as thickness 205 shown in Figure 1, or from a variable tliickness tailored for
any desired change
in flow rate witli respect to pressure, such as thickness 206 in Figures 2 and
3. The structural
properties of diaphragms being relatively well known, and hydrostatic pressure
being given by the
equation
sp = pgh,
where p = pressure, p'= the specific gravity of the liquid to be drained
through the valve, g= the
local acceleration due to gravity or other body force acting on the liquid,
and h= head, as shown
by reference 204 in Figure 5. Thus, is it a straightforward matter for one
having ordinary skill in
the art, once armed with this disclosure, to select an appropriate head 204
and to design a
diaphragm 203 which will deflect suitably in the presence of that head and
permit the liquid to
drain into the conduit 110.
An optional alternative means for tailoring the deflection of diaphragin 203
under any given
head of water or for otherwise increasing or affecting the stiffness of the
plate is through the use
of a back plate on one side of the diaphragm. Most commonly such a plate will
be placed on the
drain side of the diaphragm, as shown in Figure 9, but the effect of water
accumulating in the drain
basin on the diaphragm may be affected as well by placing the back plate
before the diaphragm.
Typically a back plate such as plate 107 in Figure 9 will support at least a
portion of the diaphragm,
and depending upon the stiffness of the diaphragin and the plate may support
the entire diaphragm.
In alternative preferred embodiments of this aspect of the invention the check
valve
comprises a spring or extendable mounting cord adapted to urge the stop into
sealing engagement
with the drain sealing surface. Such an embodiment is shown in Figure 7. Check
valve 300
comprises stop 302 and spring 309, which serves to bias stop 302 into sealing
contact with sealing
surface 301. As shown in Figure 7, spring 309 is compressed under action of
liquid in the drain,
the motion of which is represented by arrows 17, so as to allow stop 302 to
disengage from sealing
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surface 301, and therefore to allow the liquid to drain. As will appear to
those of ordinary skill in
the art, it is a relatively simple matter to select a spring 309 having an
appropriate stiffness to allow
stop 302 to disengage the sealing surface when a desired level of liquid has
accuinulated in the
drain. In general, it has been observed that under some circumstances the
selection and fabrication
of a spring having just the desired stiffness may be more difficult than
making a flexible diaphragm
of the type described herein having an appropriate flexibility and elasticity.
One advantage of providing check valves according to the invention with on
optional
housing such as housing 110 or 210 in the Figures is that the housing may be
provided with
convenient means for installing and removing the check valve in a floor drain.
For example, ring
111 in Figures 4-6 permits removal of the check valve. In addition to
providing an attachment for
the installation and removal means housing 110 or 120 provides structural
support for stop 302 or
diaphragm and the biasing means, and optionally a drain sealing surface 201.
In embodiments of
the invention coinprising flexible diaphragms 203, the housing may include
cross members 114
or other structure to provide direct attachment for the diapllragm, as by
means of fastener 115,
which may consist of a rivet, nut and bolt, or other mechanical fastener.
Alternatively, the
diaphragm may be attached with adhesive or with a bonding process, or
integrally molded.
Similarly, diaphragm 203 and spring 309 may be supported by means of cross
members 114 and
fasteners 115 or by any other suitable method.
It may be seen that check valves according to the invention may be of
arbitrary cross section
or plan view. That is, they are readily adaptable to use with drains of
circular cross section, as in
the case of an ordinary drain pipe, or with rectangular conduit or conduit of
any other shape.
Einbodiments of the invention adapted for use with pipes or conduits of
substantially circular cross
section are shown in Figures 4 and 8.
A further advantage of the use of check valves according to the invention is
that they may
be used singularly, as preferred, or in combination with other valves in any
number. For example,
two check valves according to the invention may be used in series, or in
parallel. One particularly
useful combination is shown in Figures 8 and 9, wherein a check valve
according to the invention
is housed in series with a series of side-port flapper valves 121. Side port
flapper valves 121 are
set in the side of housing 110 and comprise ports 122 and valve covers 123. A
valve cover 123
is hinged along one edge of each of ports 122 and adapted to open under
influence of liquid present
in drain basin 11, as shown in Figure 5. In preferred embodiments, valve
covers 123 are fabricated
from flexible elastic material such as sheet rubber (which may be either
natural or synthetic, and
coinposed of any suitable material) and are fastened or adhered along the top
edge of their
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associated ports. As in the case of flexible diaphragms 203, valve covers 123
may be tailored by
means of thickness (uniform or nonuniform) or material to open under any
design hydrostatic
pressure. It is advantageous, but not necessary, in making side port flapper
valves to provide
housing 110 with sloping sides 124, so that valve covers 123 are assisted by
gravity or otlier body
force in closing, so as to help prevent back flow of gasses from the interior
of the drain conduit.
Check valves and associated coniponents of the invention are advantageously
made from
any suitable materials. For example, diaphragms and stops' may be fabricated
from natural or
synthetic rubbers, or other suitable pliant and resilient materials, including
a great many polymers,
while stops and housings may be made of plastics such as PVC or APP, metals,
or any of a wide
variety of other materials.
With regard to systems and components above referred to, but not otherwise
specified or
described in detail herein, the workings and specifications of such systems
and components and
the manner in which they may be made or asseinbled or used, both cooperatively
with each other
and with the otller elements of the invention described herein to effect the
purposes herein
disclosed, are all believed to be well within the knowledge of those skilled
in the art. No concerted
attempt to repeat here what is generally known to the artisan has therefore
been made.
INDUSTRIAL APPLICABILITY
The invention has applicability in the field of plumbing and liquid control or
removal. In
particular, the invention represents improvements in drain systems for floors
and otlier surfaces in
which infrequent drainage must be reliably and efficiently processed.
In compliance with the statute, the invention has been described in language
more or less
specific as to structural features. It is to be understood, however, that the
invention is not limited
to the specific features shown, since the means and construction shown
comprise preferred forms
of putting the invention into effect. The invention is, therefore, claimed in
any of its forms or
modifications within the legitimate and valid scope of the appended claims,
appropriately
interpreted in accordance with the doctrine of equivalents.
