U.S. patent application number 10/223732 was filed with the patent office on 2004-02-26 for grated drain basket with seal collar.
Invention is credited to McGinn, John.
Application Number | 20040035772 10/223732 |
Document ID | / |
Family ID | 31886685 |
Filed Date | 2004-02-26 |
United States Patent
Application |
20040035772 |
Kind Code |
A1 |
McGinn, John |
February 26, 2004 |
Grated drain basket with seal collar
Abstract
The present invention is a basket that is sealingly insertable
in a grated drain. The basket is formed from inexpensive but
surprisingly tough and effective polymer grating to which is bonded
polymer sheet at the upper basket edges. The polymer sheet is wide
enough so that it the grate of the grated drain can be picked up
and put back into its concrete inset, capturing the polymer sheet
edges under its heavy weight. The captured polymer sheet forms a
peripheral seal between the pavement surface and the drain so that
substantially all the water must pass through the basket.
Inventors: |
McGinn, John; (Alameda,
CA) |
Correspondence
Address: |
David T. Bracken
The Law Office of David T. Bracken
4839 Bond Avenue
Orange
CA
92869
US
|
Family ID: |
31886685 |
Appl. No.: |
10/223732 |
Filed: |
August 20, 2002 |
Current U.S.
Class: |
210/163 |
Current CPC
Class: |
B01D 29/111 20130101;
B01D 29/23 20130101; E03F 1/00 20130101; E03F 5/0404 20130101 |
Class at
Publication: |
210/163 |
International
Class: |
E03F 005/06 |
Claims
I claim:
1. An easily insertable and removable drain box for grated drains
with a grate that is supported from a support ledge comprising: (a)
the grated drain having a drain passage below the support ledge
with support means lodged in walls of the drain passage where open
top box substantially all of polymer mesh with a top opening about
the size of a lateral cross section of the drain passage of the
grated drain is supported on the support means; (b) a flexible
waterproof sheet sealingly attached to a top edge of the open top
box and draped upward over at least substantially the entire
periphery of the support ledge; and (c) the grate supported from
the support ledge so that its weight sealingly captures a periphery
of the flexible waterproof sheet.
2. The drain box of claim 1 wherein the drain box is formed from
two half pieces.
3. The drain box of claim 2 wherein at least one of the half pieces
is formed from a flat sheet of polymer mesh.
4. The drain box of claim 1 wherein the drain box comprises filter
media covering a bottom section so that at least part of water
flowing from the pavement level is filtered therethrough.
5. The drain box of claim 4 wherein the drain box comprises filter
media on a lowermost periphery of walls of the drain box and
sealingly continuous with filter media on the bottom section.
6. The drain box of claim 1 wherein polymer mesh defines openings
spaced from about 0.1 to about 0.3 inches apart and have hydraulic
cross sections of from about 0.1 square inches to about 0.7 square
inches.
7. The drain box of claim 6 wherein the polymer mesh is from about
0.2 inches to about 0.5 inches thick.
8. The drain box of claim 1 wherein the drain box is formed from
two half pieces.
9. The drain box of claim 3 wherein the polymer mesh is
foldable.
10. The drain box of claim 9 wherein the flat piece of polymer mesh
defines two cut lines so that side parts are folded forming overlap
zones in the assembled box.
11. The drain box of claim 3 wherein two half pieces are slidable
over each other's mirror image bottom and side sections thereby
shortening or lengthening the box.
12. The drain box of claim 11 wherein an overlap of the two half
pieces at the bottom and side sections is secured together.
13. The drain box of claim 1 wherein pocket means formed at top
edges of the drain box are adapted to encase rigid support
rods.
14. The drain box of claim 13 wherein two pocket means opposite
each other secure legs of a U-shaped rigid support rod.
15. The drain box of claim 14 wherein pocket means between the two
opposite pocket means secures a bottom section of the U-shaped
rigid support rod.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to grated water drains with
inserts for capturing particulates and water contaminants.
[0002] The standard grated drain has a concrete support formed so
that the top surface of the heavy duty grate lies flush with the
top of the pavement. The pavement level is usually one where cars
and trucks or other heavy vehicles pass over the grate. Typical
locations for grated drains are in parking lots and in factories or
manufacturing facilities where water gathers in sufficient quantity
to require underground drainage. The grated drains often flow to
environmentally sensitive bodies of water or to treatment
facilities unable to process contaminants that are present in the
water.
[0003] One way to try to capture a limited amount of particulates
and liquid borne contaminants is described in U.S. Pat. No.
5,720,574. In that patent is described a structure for use with
grated drains where an outside wall portion, a perforated bottom
portion, and an inside wall portion form a trough for retention of
a replaceable filter media. The trough is installed on the inside
surface of a drainage structure so that drainage water that would
normally flow directly through the drainage structure is caused
instead to flow through the filter media, thereby removing
undesirable materials that may be carried in the water, while
permitting the water itself to pass through essentially unimpeded
to the ultimate drainage location. Unfortunately, particulate
matter that passes through the wide spaced grate effectively
eliminates the passage of water through the filter media, causing
the contaminated water to overflow the trough without passing
through it. This device is necessarily high maintenance and is
initially very costly. The metal materials must be rugged and of
high alloy steel to prevent corrosion with sufficient strength to
withstand maximum water and particulate flows typical of such
grated drains.
[0004] U.S. Pat. No. 5,720,574 intends to provide a device and
method for grated drains such as drainage inlets for sidewalks,
roads and parking lots that are drainage paths for the removal of
rainwater, irrigation water, or the like that would otherwise
accumulate on the ground surface. However, the water thus drained
from the surface by these grated drains is often undesirable and
even toxic, having collected oil, fuel, antifreeze and the like.
The device of U.S. Pat. No. 5,720,574 cannot prevent substantial
bypass of major portions of water intended for passage through the
filter media after only a relatively small amount of particulates
normally present flow into the filter media.
[0005] Other references shown a variety of designs for drain
inserts. U.S. Pat. No. 6,270,662 is an insert for use in a grated
drain with perforated bottom surface extending across the lower
periphery of the insert. A filter, resting on the perforated bottom
surface, has a peripheral edge enclosing a central portion. A
flange extends inwardly from the top edge of the outer wall past
the peripheral edge of the filter. The flange directs drainage
water past the periphery of the filter and to its more central
portion, whereupon impurities within the drainage water are
extracted and filtered water exits through the perforated bottom
surface into the drain basin. U.S. Pat. No. 6,149,803 describes a
grated drain filter with a frame of radially extending arms. The
filter includes an edge piece fixed to the end of each of the arms
and be engageable with a lip in a drain. Furthermore, the filter
includes a filter bag, supported from the edge pieces, and wherein
the filter bag has an open top for receiving water entering the
drain, so that the water is filtered as it passes through the
filter bag. U.S. Pat. No. 6,106,707 describes an insert for a
grated drain where a hopper contains a multitude of irregular,
macroscopic fragments of a hydrophobic, compliant, oil-absorbent,
copolymer material having high surface area. The fragments absorb
and retain permanently a high quantity of oil and other chemicals
passing through the hopper, while permitting a high water
flow-through rate. The fragments are held in place by a removable
bottom plate, which allows replacement of the filtering fragments,
and an internal basket. Trash and debris are collected in the
internal basket. The hopper is configured to be suspended in a
storm drain adjacent to a curb inlet on a bracket and can be
installed or serviced through a conventional manhole entry. The
hopper has a side cutout that permit iateral overflow from one of
the modular units to an adjacent one.
SUMMARY OF THE INVENTION
[0006] The present invention is a basket that is sealingly
insertable in a grated drain. The basket is formed from inexpensive
but surprisingly tough and effective polymer grating to which is
bonded polymer sheet at the upper basket edges. The polymer sheet
is wide enough so that it the grate of the grated drain can be
picked up and put back into its concrete inset, capturing the
polymer sheet edges under its heavy weight. The captured polymer
sheet forms a peripheral seal between the pavement surface and the
drain so that substantially all the water must pass through the
basket.
[0007] The polymer grating of the basket is preferably initially
fabricated in an inexpensive sheet and formed into two pieces that
are joined to form the basket. The formed basket can then support
filter media from its upper concave or lower convex surface. The
polymer sheet that extends from the periphery of the basket edges
is preferably welded or heat sealed to the basket edges in an
inexpensive fabrication step. The entire price of the invention
basket and sealing polymer sheet is a fraction of the device of
U.S. Pat. No. 5,720,574.
[0008] Filter media appropriate for the objects of the invention
may comprise not only the traditional hydrocarbon capturing
materials such as carbon in particles or arranged on a support,
zeolites or ceramic absorbents, or diatomaceous earths, but also
materials such as layered or packed fiberglass insulation or
natural fiber (wood and cloth) and other such high surface area
materials that will adhere 7 or more carbon hydrocarbons and other
typical water contaminants from parking lot, street, industrial or
agricultural runoff.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1, 2 and 3 are respectively bottom endward
perspective, bottom corner perspective and closer bottom corner
perspective views of a half piece of a preferred invention
basket.
[0010] FIG. 4 is a close-up view of a polymer mesh preferred for
construction of the invention basket.
[0011] FIGS. 5 and 6 are respectively top perspective and bottom
corner perspective views of a half piece of the invention basket
with a polymer sheet bonded to a top edge.
[0012] FIG. 7 is a top view of two half pieces of the invention
basked attached at an overlap zone with one half piece being
substantially the same as the half piece of FIGS. 5 and 6.
[0013] FIG. 8 is a preferred outline of a flat sheet of polymer
grating as in FIG. 7 showing fold and cutout lines to form an
invention one half piece of the invention basket.
[0014] FIG. 9 is substantially the piece of FIG. 8 with side and
end parts folded into final construction orientation except without
extensions to form pockets.
[0015] FIG. 10 is an exemplary grated drain.
[0016] FIG. 12 shows the invention basket supported in the drain of
FIG. 10 on spaced apart rods and where the polymer sheet is draped
upon the support ledge of the grate.
[0017] FIG. 13 shows the basket and drain of FIG. 12 with the grate
capturing the polymer sheet on the surface of the support
ledge.
[0018] FIG. 14 shows a side cross section of the invention basket
indicating potential locations of filter media.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The invention is now discussed with reference to the
figures.
[0020] FIGS. 1-3 show an invention half piece 100 of the assembled
invention basket. Half piece 100 comprises an end 101, sides 102,
and bottom 104 of a generally one half box structure. An important
aspect of the invention is to provide a drain box insert that can
be formed from polymer mesh, the polymer preferably formed from
thermoplastic polymers so that fabrication welds and connections
can easily be made with the appropriate plastic welding or heat
sealing techniques to provide exception resistance to tear and
loading. A preferred polymer for the polymer mesh is inexpensive
and chemically resistant polyethylene. Using a sheet of foldable
thermoplastic polymer allows folds to be made along lines 105, 107
and 108 with an optional overfold section 109 resulting from
material folded up along line 108 after being cut at line 103.
[0021] FIG. 4 shows a form of preferred polymer mesh. It has been
found after much experimentation that several variables affect the
choice of mesh opening size and mesh thickness and strut width. For
devices that will receive waste liquids and potentially be too
contaminated or difficult to clean to keep in consideration of cost
and hazard to maintenance personnel, it is critical that low cost
be achieved with full filtration ability. The prior art devices
have failed to achieve anything like a low cost device for adequate
filtration as in the present invention.
[0022] A preferred polymer mesh of the invention is about 1/4 inch
thickness polyethylene mesh with a diagonal opening width of 1/4
inches. The opening size can be varied so that the hydraulic area
of the mesh opening is about one half to twice that of 1/4 inch
thickness polymer mesh with a diagonal opening width of 1/4 inches.
If the opening is too small, the basket size must increase to an
unmanageable size to accommodate typical flows. If the opening is
too large, structural strength of an economical mesh is compromised
and too many particulates will pass through the mesh opening with
water flow. The preferred polymer mesh will be lightweight for ease
in maintenance, insertion and removal and accomplish the objects of
the invention. One object of the invention is to use polymer mesh
manufactured at low cost in sheets to form the invention boxes.
Another object of the invention is to form half pieces in such a
manner that they can be welded, bonded or secured together after
initial manufacture so that they can make a box with variable
length. It is another object of the invention to form a polymer box
with a sealing polymer sheet at a top edge to be secured between
the grate and its support ledge.
[0023] FIGS. 5 and 6 show the half piece of FIGS. 1-3 with a
polymer sheet 300 bonded, welded or sealingly secured to a top edge
1 10 of half piece 100. A polymer sheet according to the invention
is not intended to support the weight of the invention box. Its
thickness need only be more than about 0.5 mils or less to form an
effective and low cost seal between the box edge 110 and the grate
support ledge so that substantially all pavement level water and
liquid is forced into the basket for filtration. Support for the
inserted invention basket is by widely space support rods, or their
equivalent, mounted in the walls of the drain far enough below the
level of the grate support ledge so that the height of the basket
and filter media is accommodated. Polymer sheet 300 is flexible and
preferably thin, although it may be quite wide to accommodate
support of the invention basket far beneath the level of the grate
ledge. It is preferred for longer life to form polymer sheet 300
(preferably also substantially the same polymer as the polymer mesh
200 for ease in welding or heat sealing) with a thickness of
greater than about 1-2 mils.
[0024] One form of the invention basket is shown in FIG. 7. Two
half pieces 100 are joined at overlap 113. Before the half pieces
are joined at overlap 113, they may be further moved apart to
together, sliding over one another with respect to bottom 101 and
sides 102 along path 114. This sliding motion makes the invention
box longer or shorter when bonded at overlap 113. The invention
method of producing an insertable drain box comprises making two
half pieces of the same size from a polymer mesh so that they can
form a box of variable length, a valuable improvement where a
user's several drains are of different lengths. The user may then
avoid costly inventory build up of some boxes that are too long
while running short of those of lesser length.
[0025] A form of the outline of polymer mesh that will form the
half pieces of FIGS. 1-3 is shown in FIGS. 8 and 9. All internal
lines inside the outline are fold lines except for cut lines 103. A
fold over zone 109 is shown in broken lines in FIG. 8. Optional
extensions 112 are formed in the outline of FIG. 8 only. Extensions
112 can be folded inward or outward as shown in the edge lengthwise
cross section of FIG. 10 so that mesh 200 that extends upward from
edge zone 110 is folded at line 115 and brought over to form a
pocket about a rigid support 117, where the mesh is bonded at
location 117 to on itself. The pocket formed from the folding and
bonding operation for the extensions 112 shown in FIG. 8 permits
insertion of rigid supports, such as steel rods, after fabrication
of the half piece. In a preferred embodiment, four pockets are
formed along lines of extensions 112 for the two ends 102. After
fabrication of the half piece to the form shown in FIGS. 1-3, the
legs of a substantially square U-shaped steel rod are inserted into
open ends adjacent to bottom 101 and the legs of another
substantially square U-shaped steel rod are inserted into open ends
adjacent to end 104. The rods are inserted until the bottom of the
U-shaped rod can be captured in the remaining extensions from
bottom 101 and end 104, as the case may be. These rods provide
additional support for the invention basket.
[0026] FIG. 11 shows a prior art grated drain with a drain
structure 118, support ledge 120 for the grate 122, a pavement
level 119 for the top of the drain structure where the drain
passage 121 is defined by the four walls of the drain structure
118.
[0027] FIG. 12 is a side cutaway view of FIG. 11 with the invention
box and sealing sheet resting on spaced apart rods 123. Rods 123
are about 1/4 to 1/2 inches spaced apart about 2-3 inches or more
to support the weight of the invention box when it is full of
water, filter material and/or rubbish or mud. Flexible sheet 300 is
shown bonded at section 110 to the polymer mesh and draped over
support ledge 120 up toward the top opening of structure 118. Grate
122 is shown in FIG. 12 so that it can be dropped in direction 124
to rest on support ledge 120, capturing an entire periphery of
flexible sheet 300 between the grate 122 and support ledge 120.
[0028] FIG. 13 shows substantially the same structures as in FIG.
12, although optional continuous gasket material 127 is placed all
around on support ledge 120 before lowering grate 122 into place to
form compressed seal interface 128 all around support ledge 120.
With the heavy grate 122 in place as in FIG. 13, flexible sheet
material prevents bypassing of water around the invention basket
and filter media. Paths 125 show that water cannot flow under
flexible sheet 300, but must pass through polymer mesh of the
invention basket in order to reach the drain passage 121.
[0029] FIG. 14 shows side wall zones 132 for sides of the invention
basket and a single bottom zone 134 for the bottom of the invention
basket. Filter media is preferably secured and/or bonded over all
of lower surface 133 and/or upper surface 129 of bottom 101 so that
at least some portion of water draining into the invention basket
is filtered through such media. To increase the amount of liquid
filtered, filter media is preferably secured and/or bonded over at
least a lowest portion of outer surface 131 and/or inner surface
130 of sides 102 and ends 104 peripherally so that at more of water
draining into the invention basket is filtered through such media.
In another embodiment, all of the inside and/or outside surfaces of
the invention basket are sealingly secured and/or bonded over those
surfaces so that all liquid entering the invention basket must pass
through the filter media. It is well disclosed in the prior art
that filter media of predictable porosities may be chosen to remove
design levels of impurities for design levels of liquid flow
through those filter media. The invention basket can be adapted so
that widely spaced support grating or additional polymer mesh can
sealingly hold the filter media in place.
[0030] An alternate embodiment of the present invention is shown in
FIGS. 15 and 16. Grated drains are sometimes installed in
combination with curb drains, which combination changes important
requirements for drain baskets. FIG. 16 is a side cutaway view of
such a combination with the invention basket device installed, also
shown in a side cutaway view similar to that of FIG. 12. In FIG.
16, a grate 122 applied in direction 124 to inset ledge 120
substantially below street level 121, where that grated drain may
be installed immediately in front of a curb 141 with drain opening
142. Flow of liquids is generally from street level 121 and
accumulated curb flow (not shown) into the drain opening 142 and
through grate 122 when set in place.
[0031] FIG. 15 shows a preferred embodiment of the alternate
embodiment of the invention where a half piece 100 as previously
described is joined at living hinge or fold line 139 to hinge piece
135. It will be appreciated from inspection of FIGS. 15 and 16 that
hinge piece 135 may securely and sealingly rotate about line 139.
It is intended that such rotation allow the top edge 140 of front
section 137 to come to rest against a rear most wall of the curb
drain, as shown in FIG. 16, when the half piece 100 is place in
effective position under the grate 122. The particular construction
of hinge piece 135 allows the basket to adapt to a substantial
range of depths 144 for grated drain and curb drain combinations.
One invention combination of half piece 100 and hinge piece 135 can
sealingly fit may depths 144 by allowing edge 140 of front section
137 to come to rest against the back wall. Hinge piece 135 further
comprises side sealing sections 136 with top edges 138, which
sections 136 are formed to effectively span the distance from the
side edges of front section 137 to past the front free edges of
sections 102 of half piece 100 so that liquid falling into the
basket must pass through the desired polymer mesh (of which piece
135 is formed) without bypassing desired filtration materials of
the invention basket. Connection between sections 102 and sections
136 are made with polymer welding, stapling or other means
sufficient to result in full filtration of liquid entering the
basket.
[0032] Another improvement found in the embodiment of FIGS. 15 and
16 is the sealing attachment of flexible sheet material 300 about
the top periphery of the basket, i.e., along the top edges of
sections 102 and 104 and edges 138 and 140. As in the previous
embodiments, sheet material 300 can be captured in inset 120,
although that capture is only on three sides for the drain
structure of FIG. 16, substantially only for the flexible sheet
material above section 104 and most of sections 102. The rest of
the "un-captured" sheet material 300 may still provide effective
seal to the inside walls of the curb drain by adhesive or stapling
attachment of the "un-captured" sheet material 300 to a location on
those inside walls above the level of the top edges of the basket.
Thus, water flowing in direction 143 and splashing toward the side
or rear inside walls of the curb drain will flow into the
filtration surfaces of the invention basket.
[0033] The above design options will sometimes present the skilled
designer with considerable and wide ranges from which to choose
appropriate apparatus and method modifications for the above
examples. However, the objects of the present invention will still
be obtained by that skilled designer applying such design options
in an appropriate manner.
* * * * *