1. Field of the Invention
The subject invention relates to shutter assemblies and more specifically to shutter assemblies formed from cementitious slurries and/or urethane-based materials.
2. Description of the Related Art
Many different modern building designs take advantage of modular shutters for purely aesthetic purposes to decorate exterior windows. The modular shutter assemblies are generally an assembly of plastic parts that are individually formed and then secured together in a cost effective manner. The different plastic parts can be formed by different plastic fabrication techniques such as injection molding and extrusion. The plastic parts are secured together by appropriate fastening mechanisms, such as screws, adhesives, and/or the like, in a manner that is well understood in the art.
Because the shutters are employed for purely aesthetic purposes, it is important to choose an appropriate shutter style that complements, rather than detracts from, the exterior wall surface of the building onto which it is to be mounted. In this respect, certain buildings, especially upscale residential and commercial buildings having stucco, stone, and/or brick exterior walls, are generally not enhanced by the use of plastic, or even metallic, shutters, regardless of the quality and/or cost thereof. That is, the use of a plastic or metallic shutter does not, from an aesthetic viewpoint, coordinate very well with a building having stucco, stone, and/or brick exterior walls.
Additionally, it has been problematic to install shutter assemblies to the building's exterior walls without having to drill large and deep holes therein to accommodate screws that hold the shutter assemblies securely in place. These holes provide ingress for water, dirt, insects, and/or the like that could damage the wall or other surrounding structures. Toward this end, certain municipalities have enacted regulations on if, and how, holes can or cannot be provided in exterior walls for any purpose, including the hanging of shutter assemblies.
Therefore, it would be advantageous to provide shutter assemblies that overcome at least one of the aforementioned problems.
The subject invention provides a shutter assembly having a foam core enveloped by a cement or cementitious exterior shell or alternatively, by a urethane-based material, such as but not limited to a two part urethane filled with a lightweight fly ash. The cementitious or urethane-based shell can also be provided with an optional hanger member that allows the shutter assembly to be mounted to a dwelling, e.g., via a bracket affixed to an exterior wall surface thereof. The shutter assembly can be formed in a closed mold from a cementitious slurry comprising gypsum cement (e.g., white or grey Portland cement) and water or alternatively, from the urethane-based material. The slurry or urethane-based material can also contain other materials such as but not limited to reinforcement materials (e.g., fibers), as well as other materials that are known in the art (e.g., plasticizers and/or the like). An appropriate amount of the cementitious slurry or urethane-based material can be added onto a bottom mold surface portion to a desired depth. If the optional hanger member is to be used, it would preferably be placed onto the bottom mold surface portion prior to the introduction of the cementitious slurry or urethane-based material. The foam core is then placed atop the cementitious slurry or urethane-based material in a desired orientation, the mold is vibrated and pressure is applied to close the mold to a predetermined thickness, such that the top mold surface portion is brought into contact with the bottom mold surface portion. After an appropriate curing or drying time, the shutter assembly is removed from the mold and is ready for immediate use and/or further processing, such as but not limited to painting and/or the like.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposed of illustration only and are not intended to limit the scope of the invention.
Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
The same reference numerals refer to the same parts throughout the various Figures.
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, or uses.
Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a shutter assembly is generally disclosed at 10. By “assembly,” as that term is used herein, it is meant at least one shutter member.
The shutter assembly 10 can be mounted, either permanently or temporarily to a dwelling 12, such as a residential or commercial building, especially one that includes a stucco, stone and/or brick exterior.
Although raised/recessed panel shutter members are shown in connection with the shutter assemblies 10 in
It is to be understood that one shutter assembly 10 according to the subject invention is a single shutter 20. That is, one shutter assembly 10 is one left side shutter 20 or one right side shutter 20 such that two shutter assemblies 10 are preferred. For example, with specific reference to
The shutter assembly 10 includes a foam insert or core 100 that is completely or at least substantially completely enveloped or surrounded by a cementitious shell or coating 102. Various portions of the cementitious shell 102 can be permitted to infiltrate through various crevices, apertures, or spaces formed in the foam core 100, e.g., so as to form reinforcement or rib members 104 at various locations within the shutter assembly 10.
In accordance with one aspect of the present invention, the cementitious shell 102 is formed from a cementitious or cement slurry. The slurry can include hydraulic cement including, but not limited to, Portland, sorrel, slag, fly ash, or calcium alumina cement. Additionally, the cement can include a calcium sulfate alpha hemihydrate or calcium sulfate beta hemihydrate. The slurry can also utilize natural, synthetic, or chemically modified beta gypsum or alpha gypsum cement. The cementitious slurry preferably includes gypsum cement and a sufficient amount of water added thereto to produce a slurry having the desired consistency, i.e., not too dry nor not too watery.
Gypsum is a naturally occurring mineral, calcium sulfate dihydrate, CaSO4.2H2O (unless otherwise indicated, hereafter, “gypsum” will refer to the dihydrate form of calcium sulfate). After being mined, the raw gypsum is thermally processed to form a settable calcium sulfate, which can be anhydrous, but more typically is the hemihydrate, CaSO4.½H2O. For the familiar end uses, the settable calcium sulfate reacts with water to solidify by forming the dihydrate (gypsum). The hemihydrate has two recognized morphologies, alpha and beta hemihydrate. These are selected for various applications based on their physical properties. Upon hydration, alpha hemihydrate is characterized by giving rise to rectangular-sided crystals of gypsum, while beta hemihydrate is characterized by hydrating to produce needle-shaped crystals of gypsum, typically with large aspect ratio. In the present invention, either or both of the alpha or beta forms can be used, depending on the mechanical performance required. The beta form generates less dense microstructures and is preferred for low density products. Alpha hemihydrate could be substituted for beta hemihydrate to increase strength and density or they could be combined to adjust the properties.
The cementitious slurry can also include other additives. The additives can include, without limitation, accelerators and retarders to control setting times of slurry. Suitable accelerators include aluminum sulfate, potassium sulfate, and Terra Alba ground gypsum. Additional additives can be used to produce colored shutter assemblies 10, such dry powder metallic oxides such as iron and chrome oxide and pre-dispersed pigments used for coloring latex paints.
In accordance with one aspect of the present invention, a reinforcing material can also be disposed within the cementitious slurry, either prior to or after the introduction of the water thereto. The reinforcing material can include, without limitation, fibers, e.g., either chopped or continuous fibers, comprising at least one of polypropylene fibers, polyester fibers, glass fibers, and/or aromatic polyamide fibers. By way of a non-limiting example, the reinforcing material can include a combination of the fibers, such as the polypropylene fibers and the glass fibers or the polyester fibers and the glass fibers or a blend of the polypropylene fibers and the polyester fibers and the glass fibers. If included in the fiber composition, the aromatic polyamide fibers are formed from poly-paraphenylene terephthalamide, which is a nylon-like polymer commercially available as KEVLAR® from DuPont of Wilmington, Del. Of course, aromatic polyamide fibers other than KEVLAR® are suitable for use in the fiber composition of the subject invention.
The cementitious slurry can then be mixed, either manually or automatically, so as to adequately combine the various ingredients thereof and optionally can also be agitated, e.g., by a vibrating table, to remove or lessen any air bubbles that formed in the cementitious slurry.
Referring to
A mold surface member 206 is preferably disposed within a cavity 208 formed in the lower or bottom mold surface portion 202. Although the lower or bottom mold surface portion 202 is shown as being an open shell having a substantially rectangular configuration, the lower or bottom mold surface portion 202 can have any number of various configurations. The mold surface member 206 can be formed of any type of material, such as rigid or flexible materials; however, preferably the mold surface member 206 is formed from a suitably flexible material that, e.g., can be removed from the cavity 208. The face 206a of the mold surface member 206 is essentially a negative image of the desired front exterior surface shape of the shutter assembly 10. Additionally, the mold surface member 206 preferably includes a peripheral lip member 210 to aid in grasping the mold surface member 206, e.g., when it is desired to remove the mold surface member 206 from the cavity 208. The foam core or insert 100 and an optional hanger member 300 are shown for illustrative orientation purposes.
Because of the weights involved of the various components, as well as the cementitious slurry, a transport device, such as a conveyor system 350 (e.g., see
After the cementitious slurry has been prepared, as described above, the cementitious slurry, preferably when still wet, is then poured into the bottom mold surface portion 202, either manually or mechanically, such that it contacts and fills the mold surface member 206 to a desired depth (e.g., see
With specific reference to
As noted, once a sufficient amount of the cementitious slurry is disposed onto the mold surface member 206, the foam core or insert 100 is then placed onto the cementitious slurry and is properly positioned in the mold in a desired orientation. The cementitious slurry initially penetrates through any crevices, apertures or spaces between adjacent portions of the foam core or insert 100, such as the crevices, apertures or spaces formed between the individual slat members 100a and in this manner forms the reinforcement or rib members 104 previously described. Optionally, a vibratory force can be applied to the mold system 200, e.g., to remove any residual air bubbles in the cementitious slurry, e.g., either before or after the foam core or insert 100 is placed therein.
With specific reference to
In accordance with one aspect of the present invention, the upper or top mold surface portion 204 can be secured to the lower or bottom mold surface portion 202 with fastening devices 400 so as to prevent the upper or top mold surface portion 204 and the lower or bottom mold surface portion 202 from becoming inadvertently dislodged from one another. The cementitious slurry is then allowed to dry, harden or cure for a sufficient amount of time, which may depend, at least in part, on the specific composition of the cementitious slurry used. The mold system 200 can also be shuttled off of the conveyor system 350 and stored in a storage area (not shown) so that other shutter assemblies can be made in the interim.
With specific reference to
Referring to
In this embodiment, the same basic process is used as for the shutter assembly formed from the cementitious slurry, that is, to produce an inner core in the shape of the shutter out of foam material (e.g., expanded polystyrene (EPS) board) and then produce the shutter using a two stage pour process. The mixture for the face of the alternative shutter assembly 500 (e.g., the volume is calculated so that the shutter is only filled to the half way mark when the foam core displaces the liquid urethane mixture) is poured into a rubber tool (e.g., a mold face) and the EPS insert 502 (which forms the core of the alternative shutter assembly) is positioned on top of this mixture. The back of the tool (e.g. opposing mold face) is closed and this pushes the EPS insert 502 into the liquid urethane mixture to a specific depth. The urethane mixture then gels very quickly (e.g., 180 seconds) to form a front shell portion 500a and becomes hard enough to open the tool (e.g., mold) in about 10 minutes. The second half of the urethane mixture, which been calculated to fill another specific volume, is then poured over the EPS board to form the back shell portion 500b of the alternative shutter assembly 500, i.e., it is allowed to flow, with or without vibrating, such that it preferably self levels to form a relatively smooth back surface of the alternative shutter assembly 500.
The resulting alternative shutter assembly 500 has improved qualities over the previously described cement-based shutter assemblies, such as but not limited to: (1) it produces a much lighter shutter, e.g., a 15×31 inch cement-based shutter would weigh from 14 to 16 pounds whereas a fly ash/urethane unit will weigh from 4 to 6 pounds; (2) the cement-based shutter assembly, although possessing great compressive strength, had little flexural strength and henceforth was a problem to securely package and ship without the risk of damage, whereas the fly ash/urethane shutter assembly 500 was much more durable; and (3) there were paint issues with the cement-based shutter assembly because of the high pH of the material, whereas the fly ash/urethane shutter assembly 500 could be painted with conventional painting equipment.
There was one problem that presented itself with the fly ash/urethane alternative shutter assembly 500, that being thermal expansion. The structure of the alternative shutter assembly 500, as an organic material that skinned an insulating core, meant that one face would be heated by the sun and one face would remain cool. This would cause the heated side to expand and cause the shutter to warp temporarily. The alternative shutter assembly 500 did not expand linearly but rather “bellied out” from the center.
A solution to this problem was to mount the alternative shutter assembly 500 from the center, thus restricting the alternative shutter assembly 500 from bowing outward. To do this, one or more channels 504 were cast in the alternative shutter assembly 500 that could be opened up after casting that would allow it to be mounted on right angled mounting brackets 506 that had been fastened to a surface, e.g., a wall 508. The alternative shutter assembly 500 can then be held to the brackets 506 with a fastening member 510, e.g., a screw, through each side of the alternative shutter assembly 500 at the center point.
The alternative shutter assembly 500 also includes a relatively thinner wall thickness, as compared to the cement-based shutter assemblies, e.g., typically from about 0.060 to about 0.080 inches. However, it should be appreciated that the alternative shutter assembly 500 could have wall thicknesses less than or more than this particular range.
While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
The instant application claims priority to U.S. Provisional Patent Application Ser. No. 60/870,747, filed Dec. 19, 2006, the entire specification of which is expressly incorporated herein by reference.
Number | Date | Country | |
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60870747 | Dec 2006 | US |