Patent Application
20130185856
The present invention relates to protective covers, and more particularly relates to shapable covers for protecting vertical drains, holes and the like from spills and unwanted liquids.
It is often desirable to temporarily close off drains to prevent various liquids from flowing therein. Particularly, when handling hazardous liquids in the vicinity of a drain, such as a storm drain or manhole, it is desirable to temporarily seal off the drain to prevent any hazardous liquid that may be accidentally spilled on the ground from entering the drain. Some known methods of sealing off a drain to prevent the possible ingress of liquids include providing custom fitted rigid covers, utilizing manual or automatic cutoff valves, covering the drain with a flexible material (e.g., canvas) and covering the flexible material with dirt or sand, and utilizing a sheet of polyurethane, vinyls, and other pliable materials to cover the drain. However, these known methods of drain isolation have certain practical limitations to their usefulness.
Utilizing custom fitted rigid covers or cutoff valves requires extensive preparation and installation efforts. Manufacturing a custom fitted cover and/or installing cutoff valves are both time consuming endeavors. Neither a custom fitted cover nor an installed cutoff valve can be easily adapted for use in covering and isolating drains other than the one for which the cover or valve was specifically designed, and they cannot be driven over. Moreover, once a custom fitted cover or cutoff valve is in place in a drain or drain system, neither is readily removable and/or transportable to another location for use.
Utilizing a flexible material held in place by dirt, sand or water to seal off a drain also presents certain problems in that such a covering is difficult to work with and is cumbersome and time consuming to implement in emergency situations. The effective seal surrounding the drain is limited by the dirt or sand utilized to hold the flexible material in place, and is further limited in that the dirt or sand may be washed away or eroded during flooding. In addition, water-filled drain blockers cannot be driven over. Such a drain covering has limited reusability and transportability, and the seal effectuated thereby has little resistance to the shear forces of onrushing liquids.
Utilizing protective covers with pliable, tacky sealing layers provides effective seals on horizontal surfaces. Examples of such protective covers are disclosed in U.S. Pat. Nos. 7,950,075; 8,117,686; and 8,230,530, which are incorporated herein by reference. The inherent adhesion and weight of such covers help to maintain contact with the surface. However, when applied to vertical surfaces, the weight of the covers may not help to improve the seal, and may work against adhesion due to gravity.
The present invention is directed toward overcoming one or more the above-mentioned problems.
Shapable protective covers for vertical drains and other holes to prevent spills and other liquids from flowing therein are provided. The protective covers may be positioned over a vertical drain such that an exposed surface of a pliable, tacky sealing layer contacts a portion of the surface surrounding the vertical drain, thereby preventing a liquid from passing through the drain. The protective covers of the present invention include a backing layer with a malleable shapable core and a pliable, tacky sealing layer. The sealing layer may be secured to the other layers by a bonding layer adhered to or partially embedded in at least one of the layers.
An aspect of the present invention is to provide a protective cover for installation over a drain comprising a shapable backing layer, a bonding layer attached to the shapable backing layer, and a pliable, tacky sealing layer attached to the bonding layer structured and arranged to block spills from entering the drain.
Another aspect of the present invention is to provide a method of making a shapable protective cover for installation over a drain. The method comprises adhering a pliable, tacky sealing layer to a shapable backing layer that includes a shapable layer at least partially embedded in a polymer layer.
These and other aspects of the present invention will be more apparent from the following description.
The present invention provides shapable protective covers which prevent spills and/or other unwanted liquids from flowing into vertical drains or holes. At least a portion of the liquid is prevented from flowing into a drain or hole by the protective cover. The spill or unwanted liquid may be any flowable material such as hazardous liquids, storm water, hydrocarbons, chemicals, debris, dirt, trash and the like which are desired to be kept out of drains and the like. As used herein, the term “drain” means any drain, hole or other opening such as a curb-style drain, a pipe opening or the like through which it is desired to prevent the flow of spills or unwanted liquids. A “vertical drain” is a drain having at least a portion extending vertically such that an upper portion of the drain is at a higher elevation than a lower portion of the drain. For example, a curb-style drain may include a lower portion that is substantially horizontal, and an upper portion that extends upward from the horizontal portion at a 90 degree angle, or any other angle having a vertical component.
As used herein, the term “shapable”, when referring to the protective cover, means that the cover may be bent or otherwise formed into a desired shape that is retained after it has been bent or otherwise formed. At least the bent or shaped portion may be self-supporting such that the shaped portion maintains its shape and does not sag or collapse under its own weight, and does not require support from the drain or surrounding structure to maintain its shape. The shapable protective cover may thus be formed into the desired shape to provide a self-supporting, dimensionally stable cover capable of protecting vertical openings. In certain embodiments, the protective cover is sufficiently malleable such that it can be formed by hand into shape without the requirement of hand tools or other tools.
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Both the backing layer 18 and the pliable, tacky sealing layer 20 may resist water, oil and many chemicals making the shapable protective cover 5 suitable for use in many types of work environments, including hazardous work environments. The shapable protective cover 5 may be UV-resistant in order to resist damage when exposed to various environments. The protective cover 5 may be cleaned easily with soap and water and is reusable. The malleable shapable layer 12 allows the cover 5 to be re-shaped many times for use with various different shapes and sizes of drains.
The shapable layer 12 provides structural support to the protective cover 5 in vertical applications. The shapable layer 12 may be made of flattened expanded metal, perforated metal, wire screens, wire cloths, cross-laid metal strips or wires, parallel metal strips or wires, woven metal strips, and the like. Expanded metal may be more malleable than perforated metal, and may be easier to shape by hand. Wire screens and cloths may have an undulating surface due to the associated weaving, and can require a thicker plastic or rubber layer to cover and fuse into the open areas.
The melt-flowable sheets 10 and 11, and the fused layers 16a and 16b foamed therefrom, may be liquid impermeable, and made from flexible and durable materials. The melt-flowable sheets 10 and 11 can have tensile strengths at least 25 percent higher than the tensile strength of the tacky sealing layer 18. The melt-flowable sheets 10 and 11 can comprise any suitable material such as natural rubber, synthetic rubber, nitrile rubber or plastics such as thermoplastic olefin, polyvinyl chloride, chlorosulfonated polyethylene and the like. Such materials may include UV-resistant additives as well as any other additives that resist damage when the cover 5 is exposed to various environments. In one embodiment, the melt-flowable sheets 10 and 11 may be made of a composite material. Examples of composite materials include rubber laminated to plastic film, plastic film laminated to mesh, rubber laminated to mesh and combinations thereof The thickness of the melt-flowable sheets 10 and 11 typically ranges from 0.01 to 0.25 inch, while the thicknesses of the fused layers 16a and 16b may have a total thickness of from 0.02 to 0.5 inch.
In certain embodiments, the bonding layer 14 may comprise a low-density material used to entangle the backing layer 18 and/or the pliable, tacky sealing layer 20. As used herein, the term “low-density bonding layer” means a deep pile or lofty material having at least one surface comprising entanglement fibers that extend from the layer to provide additional surface area and attachment sites for the melt-flowable sheet 11 and/or pliable, tacky sealing layer 20. The low-density bonding layer 14 may have a density that is typically less than 0.26 ounces per cubic inch, preferably from 0.02 to 0.1 ounces per cubic inch. The low-density bonding layer 20 may have a typical thickness of at least 0.01 inch, for example, from 0.02 to 0.25 inch. In one embodiment, the thickness is from 0.04 to 0.06 inch. The low-density bonding layer 14 typically has a weight per area of less than 20 ounces per square yard, for example, from 1 to 10 ounces per square yard. The low-density bonding layer 14 provides secure and permanent attachment between the shapable backing layer 18 and the pliable, tacky sealing layer 20,
The low-density bonding layer 14 may be non-woven and may comprise entanglement fibers made of polyester, polypropylene, poly(ethylene propylene), polyvinylchloride, fiberglass, nylon, cotton, urethane and the like. In one embodiment, the low-density bonding layer 14 comprises a base or backing layer from which the entanglement fibers extend on one or both sides of the backing layer. For example, the low-density bonding layer 14 may comprise fleece made of polyester and having a thickness of 0.055 inch. The fleece assists in the adhesion of the pliable, tacky sealing layer 20 to the shapable backing layer 18.
In one embodiment, the process of fusing the melt-flowable sheets 10 and 11 through the open areas of the shapable layer 12, and fusing the lower melt-flowable sheet 11 into the low-density bonding layer 14, includes the use of heat and/or pressure to achieve melt flow. The melt flow index of the sheets 10 and 11 should be matched to the press conditions. Enough heat, pressure and dwell time should be used to fill the open areas, and can be determined by routine experimentation. One method includes the use of a hydraulic, heated, platen press. Other techniques include vacuum pressing, hot roll lamination, and extrusion coating. A hydraulic heated platen press may be particularly suitable because higher softening-point thermoplastic films can be chosen to increase temperature resistance, impact strength and resistance to deflection. In certain embodiments, the pressing process may include using uncured rubber sheets, pressing them together, and then curing by vulcanization.
In one embodiment, the bonding layer 14 can be deposited on the surface of the lower melt-flowable sheet 11 through hot air roll laminating, or brought into contact with the melt-flowable sheet 11 before it is cured or cooled so that the fibers or protuberances in the Z direction or the openings or voids in the bonding layer are at least partially embedded within the melt-flowable sheet 11. Once the fibers of the low-density bonding layer are embedded within, or otherwise adhered to, the melt-flowable sheet 11, the rest of the layers of the backing layer 18 can be hot press laminated together. The pliable, tacky sealing layer 20 can then be applied to the exposed surface of the backing layer 18 including the bonding layer 14. As the pliable, tacky sealing layer 20 cures or cools, the bonding layer 14 improves adhesion between the backing layer 18 and the pliable, tacky sealing layer 20.
The pliable, tacky sealing layer 20 is flexible and tacky such that it conforms to irregularities or roughness in the spill surface and adheres to the surface surrounding a drain to thereby provide a seal between the backing layer 18 and surface which reduces or eliminates the flow of spilled liquids. The pliable, tacky sealing layer 20 is made of a different material from the backing layer 18, and can comprise materials such as urethane, polyurethane, polyvinyl chloride and/or silicone. The pliable tacky layer 20 may have a hardness, as measured by a durometer, at least 10 percent less than the hardness of the backing layer 18. In one embodiment, the pliable, tacky sealing layer has a durometer hardness of less than 30 shore A. The pliable, tacky sealing layer 20 can comprise an inherently tacky material or can have a standard tackifier applied to any exposed surface. The pliable, tacky sealing layer 20 can have a tackiness such that it adheres to a surface surrounding a drain or hole to prevent the flow of liquid from entering the drain. In one embodiment, the pliable, tacky sealing layer 20 has sufficient tackiness such that the sealing layer adheres when pressed against a vertical wall. The tackiness of the sealing layer 20 may also be measured by other test methods known to those skilled in the art, such as rolling ball, peel and probe tests. The pliable, tacky sealing layer 20 has a typical thickness of from 0.01 to 2 inches.
In one embodiment, a mixture of various polyurethanes can be used to make the pliable, tacky sealing layer 20. A typical polyurethane mixture comprises from about 50 to about 80 weight percent polyol, and from about 20 to about 50 weight percent isocyanate. The liquid polyurethane is mixed and cured in a manner which gives it a moderate degree of inherent tackiness to all exposed surfaces of the polyurethane material. The molding and curing process creates a substantially smooth exposed surface, which may contain minor undulations. The polyurethane material is soft, yet resilient, and thus may be easily severed by a user with a knife. Surfaces of the polyurethane material which are exposed when a portion of it is severed can also be inherently tacky. While a process is described above for manufacturing polyurethane having an inherent tackiness, one skilled in the art will appreciate that other materials, such as, for example, vinyls, silicones and rubbers, may also be modified to have an inherent tackiness.
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The shapable protective covers of the present invention form effective seals around vertical drains, are generally lightweight, and are capable of quick and easy implementation even for large drains. The durable protective covers are readily reusable and transportable, and may be quickly implemented to seal a drain and/or hole in an emergency situation. The malleable and shapable core enables the protective cover to be formed many times. The protective cover may be implemented for use with a variety of different types and sizes of vertical drains and/or holes, and forms a tight seal around the vertical drain/hole to block out unwanted liquids from entering the drain or hole.
Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/589,694 filed Jan. 23, 2012, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61589694 | Jan 2012 | US |
