The present invention relates to common floor drains, residential walkout basement stairwell drains, and similar pipe drains, commonly fitted with a perforated cover intended to keep local debris entrained in the passing liquid from entering the drainpipe, and which are known to be prone to clogging in the presence of this debris.
Pipe drains and floor drains are very common in commercial and residential construction, and are effective to evacuate rain and other water and liquid sources from undesirable and sometimes damaging pooling, and, in worst cases, flooding into buildings or homes. Perforated or slotted, flat, drain covers are often a feature at the ground level, floor level, or roof level entrance to these drains to keep local debris that has been swept up in draining liquids from entering the drainpipe. Unfortunately, entrained debris can collect on the surface and in the immediate vicinity of the flat drain cover. Smaller debris that passes through the flat drain cover can clog the drain line internally. Either situation can lead to pooled liquids, such as rainwater, that can lead to pedestrian inconvenience and potentially damage to the adjacent building and property.
Various inventions have been introduced to avoid this kind of pipe drain clogging, usually by elaborations of the original construction pipe drain or pipe drain cover design. Examples include U.S. Pat. No. 4,419,232 which involves filtering components that trap debris after passing through the drain cover. This type of design requires additional components below the surface of the drain cover. Such features mean that the cover must be geometrically compatible with the original pipe and its installation details and must be removed to gain access to the filtering elements for cleaning or replacement. U.S. Pat. No. 1,791,512 describes a two-stage roof drain, but does not ensure that all liquid must pass through both filtration stages. Additionally, a significant portion of the first filtration stage is not removable for cleaning. U.S. Pat. Nos. 1,762,838; 3,529,723; and 4,525,273 have similar embodiments and are similarly limited in their installation and use for the same reasons.
Other designs have been introduced intended as supplemental devices to inhibit the clogging of original construction drain covers. U.S. Pat. No. 4,658,449 describes a swimming pool drain cover apparatus that is to be positioned over the existing drain with a somewhat dome-shaped armature structure covered with a mesh material to filter debris. Similarly, U.S. Pat. Nos. 7,005,061 B1 and 8,679,328 B2 involve a mesh material covering to be positioned over an existing drain. These devices offer only a single layer of additional filtering protection more than the perforated original construction cover. Because they are built with a rigid construction material and even a rigid structural frame to support the filtering mesh, they cannot conform to uneven surfaces. Debris can pass into the drain between the device and the mounting surface in areas where the device does not conform precisely to the shape of the mounting surface, e.g., where construction imperfections may exist such as waviness of a hand-worked surface in the vicinity of the drain. This loss of sealing would be especially evident in generally square-shaped designs (as viewed from above) in the case of a typical, conical sloping, contour formed in the drain cover mounting surface so as to direct the flow of water toward the drain.
U.S. Pat. No. 8,557,109 B1 describes a vertically-oriented, annular ring with holes to restrict the flow of debris into an open drain. This design also offers only this single vertical layer of protection with passages sized to obstruct only larger debris but allowing significant quantities of smaller debris to enter the drain. Moreover, the open top in some embodiments offers no defense from debris falling directly into the drain, such as leaves falling or blown from nearby trees.
Finally, U.S. Pat. No. 9,573,086 B2 describes a flexible rubber-like mat to cover an existing drain with vertically-oriented perforations passing through the mat to pass liquid and protrusions on the bottom surface to permit passage of liquid along the underside of the mat. This device still has the limitation of a single filtration layer and generally lacks the height necessary to “wall-off” debris as it encounters the device.
It would be desirable to have a pipe drain cover that would inhibit the passage of debris through the cover and thereby protect the covered drainpipe from clogging with debris.
It would also be beneficial to provide a drain grate cover that could be used on floor drains despite variations in design or installation details.
It would be helpful to have a floor drain grate that could be used effectively on floor drains that have uneven adjacent surfaces.
It is an object of the invention to provide for a two-stage floor drain cover that fits over an existing flat drain cover and provides enhanced protection against debris clogs.
It is further an object of the invention to supply a floor drain grate that prevents clogging on floor drains despite variations in design or installation details.
Yet another object of the invention is to provide greater liquid pass-through openings surface area than, and also additive to, the existing drain surface area, which increases the amount of debris required to block individual liquid passage openings before flow becomes restricted or impeded altogether.
A further object of the invention is an effective floor drain cover that obstructs the flow of debris from impinging upon an existing drain cover despite a non-flat condition or other imperfections in the drain cover mounting surfaces that would otherwise leave gaps and permit local debris to pass into the drain.
An additional object of the invention is a floor drain cover that can be easily removed from its normal working position over an existing drain cover without any tools or undue manipulation and that can be easily disassembled to facilitate cleaning and/or removal of trapped debris.
A preferred object of the invention is a floor drain cover that maintains its physical location over the existing drain even when subject to the dislodging forces of flowing water, wind, or physical contact from persons walking near the drain.
It is especially an object of the invention to inhibit clogging of a floor drain, most typically a pipe drain in a walkout basement stairwell or similar, so as to avoid flooding of water into the basement.
In accordance with these and other objects of the invention that will become apparent from the description herein, a floor drain grate cover according to the invention comprises: a first stage having liquid passages of a first size sufficient to block larger debris having at least one dimension greater than said first size, and a second stage having liquid passages of a second size sufficient to block smaller debris that has at least one dimension greater than said second size and that passed through the first stage liquid passages. This is a multistage device, having a domed, outer shell of hard, semi-hard, or flexible material that keeps out the bigger pieces of debris (leaves, grass clippings, . . . ), and a substantially flat, internal, more flexible strainer to filter the smaller debris that passes through the outer shell while still allowing filtered water to flow into the floor drain below the cover. The two-piece filter cover of the present invention is user separable to facilitate occasional cleaning and is readily placed into position over the existing drain and allowed to rest its perimeter edges on the surrounding concrete. A vertical post formed on the inside of the outer cover can be used to mechanically link the outer cover to the inner filter so they are installed and removed together. A somewhat longer post can also extend down into an opening in the pre-existing, flat, floor grate and help to secure the elevated cover from becoming dislodged.
Floor drain covers according to the invention are readily deployed over a wide variety of drains, especially outdoor floor drains that are exposed to a wide variety of potentially clogging backyard debris including leaves, twigs, pebbles, grass, and various plant clippings. The drain cover of the invention reliably remains in place and selectively filters debris to maintain effective drainage through the in-ground drain while also allowing tool-free removal for cleaning.
Note: The same structure or feature is identified with the same reference number in all figures.
The present invention is conveniently described with reference to a cylindrical drain cover although it will be understood that the drain cover can be of virtually any geometric shape, e.g., square, pentagonal, hexagonal, etc.
Drain covers according to the invention include an outer filtering cover and an inner filter that serves as a second stage of filtering. The outer filtering cover is dimensioned to fit over and entirely cover an existing floor drain that is usually installed with a generally flat, perforated, metal cover having holes that grossly prevent larger debris from passing into the drain line but which allow smaller objects, e.g., seeds, grass clippings, broken leaves, seeds, seed pods, etc. to pass without substantial hindrance. Over time, these passed items can accumulate and also degrade the performance of the drain. The two-part drain cover of the present invention fits over this existing drain and removes most of the small debris and matter that are likely to clog the drain.
As shown in the figures, pre-existing drain plate 1 is surrounded by drain cover mounting surface 2 and passes water into drain 3. Filtering drain grate 4 includes an outer filtering cover 5 that rises upwardly from drain cover mounting surface 2 by outer wall 6 that extends around the entire perimeter of filtering cover 5. As shown, outer wall 6 is generally vertical and rises substantially perpendicular to mounting surface 2. If desired, outer wall 6 can be sloped at an acute angle as shown in
Outer filtering cover 5 includes outwardly-slanted outer wall 6 and domed top 7 that have a plurality of first openings 8, such as first slots 9 and/or first holes 10, that are sized to permit the passage of the draining liquid (e.g., rainwater or snow melt if outdoors) for which the existing drain 3 was installed. Debris that may be entrained in the draining liquid and that is above the size of the smallest opening 8 in outer cover 5 are blocked by outer cover 5. First slots 9 on outer wall 6 are preferably oriented away from the plane of mounting surface 2, e.g., such as vertically-oriented slots. A vertical orientation can more effectively block debris that would float or become entrained in a horizontal orientation that is substantially parallel to mounting surface 2 in water flowing towards outer wall 6. Smaller debris that are able to pass through are filtered from the drain water by inner filter 11.
Another embodiment of the invention is shown in
A series of supporting ribs 14 formed into bottom side 15 of outer cover 5. Ribs 14 enhance the structural rigidity of outer cover and help to resist excessive flexing or fracture of outer cover 5 when downward forces act on top 7 such as when a person accidentally steps or stands on outer cover 5.
On top 7 of outer cover 5 is a folding handle 16 that engages handle holes 17. Handle 16 generally lays flat on top 7 but can be unfolded to lift outer cover 5 off drain mounting surface 2 for cleaning without the need for tools and to avoid placing hands into debris that has accumulated around outer cover 5.
Alternative structures can also be used in lieu of a folding handle. For example, depressions 18 or slots 19 as shown in
Inner filter 11 also includes a plurality of second openings 21, such as second round holes 22 and perimeter passages 23. Second openings 21 are generally of smaller dimensions than first openings 8, although not necessarily a smaller number of such second openings, so as to act as a finer screen against debris passing with draining liquid towards drain 3.
Because peripheral rim 24 of the inner filter 11 rests upon drain cover mounting surface 2, any liquids passing through or under outer cover 5 must then pass through second openings 21 in the inner filter 11 before reaching drain 3. The dual stage filtering effects of the present invention act to remove debris that would otherwise clog drain 3 and thereby help to maintain continued, effective, drain operation.
In general, the number of first openings 8 and second openings 21 should be as high as practicable both to maximize the potential surface area of filtering flow and to increase the number of passages that can be compromised by debris before flow falls to undesirable levels.
An embodiment of the inner filtering member 11 comprises a vertical retention pin 31 that extends downwardly from the bottom of the second filtering member so that the pin can be inserted into an opening of an existing, flat drain plate 1 that is often provided with the original installation. This pin 31 holds the drain grate cover of the invention in place against the dislodging forces of rainwater and the occasional mis-step that could kick the grate cover out of position. This feature is shown in
As described, the present invention includes two stages of filtration, but similar geometrical arrangements could provide for three or more stages, and are considered within the scope of the present invention.
Another embodiment of the invention uses a flexible material for the peripheral rim 24 or the entirety of the inner filter 11. The flexible or semiflexible properties of the material will permit peripheral rim 24 to conform to imperfections in the drain cover mounting surface 2 so as to avoid unintended gaps between peripheral rim 24 and drain cover mounting surface 2 that would otherwise undesirably permit draining water and entrained debris to pass between peripheral rim 24 and mounting surface 2.
A flexible inner filter 11 may benefit from the use of 2-10, preferably 4-8, radially extending ribs 28 on the underside of inner filter 11 to overcome flow blockage due to sagging of inner member filtering surface 29. Ribs 28 hold the filtering surface 29 away from drain mounting surface 2 and/or preexisting drain cover 1, maintaining a gap between them without which liquid flow toward the drain may be inhibited. Ribs 28 may or may not extend across the entire distance from the center of filtering surface 29 to rim 24 and may be segmented or simply vertical protrusions. As shown in
Small weep holes 23 on the underside of peripheral rim 24 can be used to avoid water from pooling outside filtering drain cover 4. Weep holes 23 should be small enough to obstruct the passage of most debris and operate to allow the last remains of water to drain at a slower rate and with less urgency, such as after rainfall has stopped, and the primary task of filtering draining water through the first and second openings 8, 21 has concluded. Depending upon the design of outer cover 5, outer cover 5 may also benefit from similar weep holes (not shown) to perform the same function.
Another embodiment of the invention provides for temporary or permanent attachment of inner filter 11 to outer cover 5 such that relative positioning of inner filter 11 to outer cover 5 is better controlled during installation and in operation. As noted above, a fitted connection between the outer and inner elements permits the user to lift both elements together in a singular movement with the outer cover. The outer cover and inner filter can be temporarily attached, such as with a friction or press fit connection, or with a somewhat more mechanical connection such as shown in
In
There are a multitude of temporary or permanent connection methods that could be used to connect outer cover 5 with inner filter 11. Non-permanent attachment systems permit outer cover 5 to be separated from inner filter 11, preferably without the use of tools, to facilitate cleaning debris from the surfaces and passages.
A center attachment position for the outer cover 5 and inner filter 11 permits the device to create a slanted orientation for filtering surface 29 of the inner filter 11 as shown in
It is understood that the description above is intended to describe preferred embodiments and is not intended to limit the scope of the appended claims.
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853598 | Rile | May 1907 | A |
1762838 | Shand | Jun 1930 | A |
4035297 | Aldridge | Jul 1977 | A |
4658449 | Martin | Apr 1987 | A |
5575903 | Kato | Nov 1996 | A |
7300573 | Trangsrud | Nov 2007 | B1 |
20160040409 | Powers | Feb 2016 | A1 |
Number | Date | Country |
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1041217 | Oct 2000 | EP |