BRIEF DESCRIPTION OF THE DRAWINGS
Without limiting the scope of the present invention as claimed below and referring now to the drawings and figures:
FIG. 1 is an isometric view of an embodiment of the gravity tub form, showing creation of the integral tub, not to scale;
FIG. 2 is a cross-sectional view of the embodiment of the gravity tub form taken along section line 2-2 of FIG. 1, showing the filling of the sidewall form portion of the gravity tub form, not to scale;
FIG. 3 is a cross-sectional view of the embodiment of the gravity tub form taken along section line 2-2 of FIG. 1, showing the filling of the top form portion of the gravity tub form, not to scale;
FIG. 4 is an isometric view of an embodiment of the integral tub, not to scale;
FIG. 5 is a cross-sectional view of the embodiment of the integral tub, taken along section line 5-5 of FIG. 4, not to scale;
FIG. 6 is an isometric view of an embodiment of the integral tub being positioned with respect to an embodiment of the gravity base form, not to scale;
FIG. 7 is an isometric view of an embodiment of the integral tub and the pouring of an embodiment of the base with the integral tub substantially in position, not to scale;
FIG. 8 is a cross-sectional view of the embodiment of the integral tub and base taken along section line 8-8 of FIG. 7, not to scale;
FIG. 9 is an isometric view of an embodiment of the leak resistant concrete septic tank, not to scale;
FIG. 10 is a cross-sectional view of the embodiment of the leak resistant concrete septic tank taken along section line 10-10 of FIG. 9, showing an exploded view of an embodiment of a joint, not to scale;
FIG. 11 is an isometric view of an embodiment of the integral tub having a partition wall, not to scale;
FIG. 12 is a cross-sectional view of the embodiment of the integral tub taken along section line 12-12 of FIG. 11, not to scale;
FIG. 13 is an isometric view of an embodiment of the leak resistant concrete septic tank having a partition wall and inspection ports, not to scale; and
FIG. 14 is a cross-sectional view the embodiment of the leak resistant concrete septic tank taken along section line 14-14 of FIG. 13, not to scale.
DETAILED DESCRIPTION OF THE INVENTION
The method of constructing a leak resistant concrete septic tank of the instant invention enables a significant advance in the state of the art. The preferred embodiments of the device accomplish this by new and novel arrangements of elements and methods that are configured in unique and novel ways and which demonstrate previously unavailable but preferred and desirable capabilities. The detailed description set forth below in connection with the drawings is intended merely as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.
Referring now generally to FIGS. 1 through 14, the present invention is a method for constructing a leak resistant concrete septic tank (50) and the resulting leak resistant concrete septic tank (50). The method may generally be described as first, pouring an integral tub (100), then allowing the integral tub (100) time to harden, followed by positioning the integral tub (100) so that a base (500) may be poured in contact with the integral tub (100), and lastly, allowing the base (500) to harden thereby forming a joint (600) between a portion of the integral tub (100) and the base (500). Now these steps will be described in detail.
In one embodiment of the instant invention, the method for constructing the leak resistant concrete septic tank (50) may begin by first creating the integral tub (100) by pouring concrete into the gravity tub form (30), as seen in FIG. 1. The concrete first fills a sidewall form portion (34) of the gravity tub form (30) to create at least one integral tub sidewall (300), as seen in FIG. 2. With continued pouring, the concrete fills the gravity tub form (30) vertically. As seen in FIG. 3, the concrete fills a top portion (32) of the gravity tub form (30) creating an integral tub cap (200). In one embodiment of the instant invention, prior to pouring an integral tub cap (200), a precast component (260) is positioned within the gravity tub form (30). Thus, as the integral tub cap (200) is poured concrete encases a portion of the precast component (260) to form the integral tub cap (200). One skilled in the art would recognize that other methods and forms may be used to create the integral tub (100). Alternatively, the gravity tub form (30) may be oriented so that the top form portion (32) fills first followed by the sidewall form portion (34). In essence then, the orientation of the gravity tub form (30) and the filling of the form (30) may be opposite to that which was previously described.
As best seen in FIGS. 4 and 5, in an embodiment of the integral tub (100), the integral tub (100) may be a monolith with the integral tub sidewall (300) having a sidewall interior surface (310), a sidewall exterior surface (320), a sidewall perimeter (330), and a base attachment surface (340). While the integral tub sidewall (300) may have a substantially rectangular shape, as seen in FIG. 4, other shapes are possible. As those skilled in the art will observe and appreciate, and by way of example and not limitation, the integral tub (100) may be formed with an integral tub sidewall (300) having a cylindrical shape. In an embodiment of the integral tub (100) having a substantially rectangular shape, as seen in FIG. 4, the sidewall perimeter (330) is formed with a sidewall proximal edge (332), a sidewall distal edge (334), a sidewall sinistral edge (336), and a sidewall dextral edge (338).
The integral tub cap (200), as seen generally in FIG. 5, has a cap interior surface (210), a cap exterior surface (220), and a cap perimeter (230). In an embodiment of the integral tub cap (200), the integral tub cap (200) may have an influent inspection port (240) that extends from the cap interior surface (210) to the cap exterior surface (220). As seen in FIGS. 2 and 3, the embodiment of the integral tub cap (200) is poured around the precast component (260) thereby forming the influent inspection port (240). However, as those skilled in the art will observe and appreciate, the influent inspection port (240) may be cut into the integral tub cap (200) at some point following the pouring of the integral tub (100). In another embodiment of the instant invention, the influent inspection port (240) may encompass the entire cap perimeter (230). In the embodiment of the integral tub (100), as seen in FIGS. 6, 7, and 9, the cap perimeter (230) generally forms a similar shape as the sidewall perimeter (330). In this rectangular embodiment, the cap perimeter (230) has a cap proximal edge (232), a cap distal edge (234), a cap sinistral edge (236), and a cap dextral edge (238), as seen in FIG. 7. As one skilled in the art will recognize, the cap perimeter (230) may have a variety of shapes and those shapes may be independent of the sidewall perimeter (330).
Once the integral tub (100) is poured, the concrete is allowed to harden until the integral tub (100) is sufficiently strong such that the integral tub (100) will support its own weight and resists fracture. In an embodiment of the instant invention, as seen in FIGS. 1 through 5, the integral tub (100) is poured with the base attachment surface (340) oriented down, although one with skill in the art will recognize that this is not a requirement of the present invention. To proceed with the construction, the integral tub (100) may be oriented with the base attachment surface (340) over a gravity base form (40), as seen in FIG. 6. In another embodiment of the present invention, reorientation of the integral tub (100) is eased by forming a plurality of gripping fixtures (322), seen only in FIG. 13, on the sidewall exterior surface (320). By way of example, and not limitation, the gripping fixtures (322) may be a plurality of indentations (323). The indentations (323) may allow a mechanical fixture to be releasably attached to the integral tub (100) and thus permit the integral tub (100) to be more easily positioned. As one skilled in the art will observe and appreciate, and as previously mentioned, the gravity tub form (30) may be constructed such that the base attachment surface (340) is up. In this orientation the integral tub sidewall (300) would be poured last and, consequently, the integral tub cap (200) would be poured first. In addition, the precast component (260) may or may not be used depending on the economics of using the precast component (260) to form the influent inspection port (240).
In the embodiment of the instant invention, as seen in FIGS. 6, 7, and 8, the integral tub (100) may be positioned within the gravity base form (40) having a gravity base form perimeter (44) at an integral tub set height (350), as seen in FIG. 8. As seen in FIG. 7, the sidewall perimeter (330) may be encircled by the gravity base form perimeter (44). The tub set height (350), best seen in FIG. 8, is measured from the base attachment surface (340) to a bottom surface (42) of the gravity base form (40).
Once the integral tub (100) is positioned at the integral tub set height (350), the base (500) is poured. Concrete is poured into the gravity base form (40), as seen in FIGS. 7 and 8, thereby contacting the base attachment surface (340) and a portion of the integral tub sidewall (300). Once poured, the base (500) has a base interior surface (510), a base exterior surface (520), a base perimeter (530), a ledge (540), and a base thickness (550), as seen in FIG. 10. In one embodiment of the instant invention, as seen in FIG. 8, the tub set height (350) is less than the base thickness (550). By positioning the base attachment surface (340) at the tub set height (350), that is, the base attachment surface (340) is positioned at a height less than the base thickness (550), the concrete may contact the base attachment surface (340) before the base (500) is fully poured. After the concrete has contacted the base attachment surface (340), with continued pouring, the concrete may proceed up the sidewall interior surface (310) and the sidewall exterior surface (320). In another embodiment of the instant invention, the integral tub set height (350) is between approximately 10% and approximately 60% of the base thickness (550). This range has been found to be particularly effective for forming a leak resistant joint (600) for 750 to 10,000 gallon tanks.
In another embodiment, the ledge (540) has a ledge width (542), as seen in FIG. 10, measured from the sidewall exterior surface (320) to the base perimeter (530), of between approximately 1 inch and approximately 6 inches. The ledge (540) may help stabilize the septic tank (50) when it is submerged within the earth by providing a surface whereby ballast, such as soil or gravel, may be added. Since flow through the septic tank (50) is due to the force of gravity, keeping the septic tank (50) at the correct elevation and orientation is critical to the system's operation.
As seen in FIGS. 9 and 10, once the poured concrete base (500) sets and hardens around the base attachment surface (340) and a portion of the integral tub sidewall (300), the joint (600) between the integral tub (100) and the base (500) is formed. As a result, the sidewall interior surface (310), the cap interior surface (210), and the base interior surface (510) enclose an influent chamber (15). The joint (600) substantially prevents a liquid influent (10) from leaking out of the influent chamber (15) through the joint (600) during operation of the leak resistant concrete septic tank (50).
In another embodiment of the instant invention, as the base (500) hardens around the portion of the integral tub sidewall (300) compressive stresses may develop in the sidewall interior surface (310). Similarly, tensile stresses may also develop in the sidewall exterior surface (320). Both the tensile and compressive stresses may develop due to contraction of the base (500) as the concrete hardens thereby pulling the sidewall (300) inward. The resulting stresses may improve the strength of the joint (600) thus making the septic tank (50) less likely to develop leaks during operation. Any external pressures, such as that due to the soil, acting upon the integral tub sidewall (300) must overcome any surface stresses that develop due to contraction of the base, in addition to the inherent strength of the concrete, before the integral tub sidewall (300) will rupture.
As one skilled in the art will observe and appreciate, the base (500), like the integral tub (100), may have other shapes. In the embodiment of the instant invention where the base (500), as seen in FIG. 9, is rectangular, the base perimeter (530) has a base proximal edge (532), a base distal edge (534), a base dextral edge (536), and a base sinistral edge (538). The integral tub (100) may also be substantially rectangular, although it is not necessary that the integral tub (100) and the base (500) have similar shapes. By way of example and not limitation, the base (500) may be circular with the integral tub (100) being rectangular, and the opposite situation is also possible. That is, the integral tub (100) may be substantially cylindrical with the base (500) being substantially rectangular.
In another embodiment of the instant invention, as seen in FIGS. 11, 12, and 13, the septic tank (50) may be formed with the integral tub (100) having an integral partition wall (400). During the step for creating the integral tub (100), concrete is poured into the gravity tub form (30). The concrete first fills the sidewall form portion (34) and a partition wall form portion (36) of the gravity tub form (30) to create the integral tub sidewall (300) and the integral partition wall (400), respectively. The concrete then continues to fill the gravity tub form (30) vertically. The concrete finally fills the top form portion (32) of the gravity tub form (30) to create the integral tub cap (200). In one particular embodiment, precast components (260) are positioned within the top form portion (32) of the gravity tub form (30). When the top form portion (32) is filled with concrete, the concrete encases a portion of each precast component (260) to form the integral tub cap (200). As seen in FIGS. 12, 13, and 14, the integral partition wall (400) has an influent chamber surface (410) and an effluent chamber surface (420). After the base (500) is poured and the joint (600) is formed, the influent chamber (15) is enclosed by the sidewall interior surface (310), the cap interior surface (210), the influent chamber surface (410), and the base interior surface (510). In addition to the influent chamber (15), an effluent chamber (25) is enclosed by the cap interior surface (210), the sidewall interior surface (310), the effluent chamber surface (420), and the base interior surface (510). A passageway (430) is cut or drilled through, or, in another embodiment, may be formed in, the integral partition wall (400). The passageway (430) fluidly connects the influent chamber (15) with the effluent chamber (25). As seen in FIG. 14, the passageway (430) is created through the integral partition wall (400) such that the passageway (430) extends from the influent chamber surface (410) to the effluent chamber surface (420).
In another embodiment of the instant invention, as seen in FIG. 14, during the step of creating the integral tub (100), the integral tub sidewall (300) has a reinforcement member (360) that is positioned substantially longitudinally within the integral tub sidewall (300). As one skilled in the art will recognize, and by way of example and not limitation, the reinforcement member (360) may be rebar that is commonly used to enhance the concrete's strength. The rebar may be straight, as seen in FIG. 14, or bent in such a manner to prevent pullout. The reinforcement member (360) protrudes from the base attachment surface (340) an extension distance (362) as measured from the base attachment surface (340) to the exposed end of the reinforcement member (360). Consequently, during the step of creating the base (500), the reinforcement member (360) extends into the base (500). The reinforcement member (360) may enhance the strength of the joint (600) making the joint (600) resistant to fracture due to the continuous pressures exerted on the sidewall interior surface (310) by the sludge, liquid, scum, and gases within the septic tank (50) and by the soil and liquid pressures bearing against the sidewall exterior surface (320). In one embodiment of the instant invention, the extension distance (362) may be less than the integral tub set height (350). In another embodiment of the instant invention, as seen in FIG. 14, the extension distance (362) is substantially equal to the integral tub set height (350). Therefore, when the integral tub (100) is positioned within the gravity base form (40), the reinforcement member (360) supports the integral tub (100) at the integral tub set height (350). When the base (500) is poured, the concrete encases that portion of the reinforcement member (360) that extends from the base attachment surface (340).
In another embodiment of the instant invention, as seen in FIGS. 9 and 10, the leak resistant concrete septic tank (50) has an influent port (800) extending from the sidewall exterior surface (320) to the sidewall interior surface (310), and an effluent port (900) extending from the sidewall exterior surface (320) to the sidewall interior surface (310). The ports (800, 900) may be cut or drilled through the sidewall surfaces (310, 320) following hardening of the integral tub (100) or following hardening of the base (500), or the ports (800, 900) may be formed during pouring of the integral tub sidewall (300). In another embodiment of the instant invention, as seen in FIGS. 13 and 14, an influent fitting (810) may be installed into the influent port (800), and an effluent fitting (910) may be installed into the effluent port (900). The fittings (810, 910) may provide connectivity to the upstream wastewater source and to the downstream treatment systems. Therefore, when the septic tank (50) is connected to a waste source, the influent (10) flows through the influent fitting (810) into the influent chamber (15) where initial treatment begins. The influent (10) then eventually flows into the effluent chamber (25) where treatment continues. Finally, with continued flow of additional influent (10) into the influent chamber (15), an effluent (20) flows out of the effluent chamber (25) through the effluent fitting (910) to a drain field or other downstream sewage treatment system.
In the embodiment of the instant invention seen in FIGS. 11 through 14, where the septic tank (50) is formed with the influent and effluent chambers (15, 25), labeled in FIG. 14 only, each chamber (15, 25) may have an inspection port (240, 250) for inspecting the ports (800, 900) or for inspecting the fittings (810, 910) or for determining the level of the scum, liquid, and sludge in each chamber (15, 25). As one skilled in the art will appreciate, the inspection ports (240, 250) also provide openings in the septic tank (50) enabling the septic tank (50) to be periodically emptied. While the inspection ports (240, 250) are shown as cylindrical extensions of the integral cap (200), as one skilled in the art will observe and appreciate, the inspection ports (240, 250) may be flush with the cap exterior surface (210) and may have a variety of other shapes. In another embodiment of the instant invention, the inspection ports (240, 250) are covered with removable lids (700), as seen in FIGS. 13 and 14. The lids (700) keep debris out of the septic tank (50) while simultaneously trapping the decomposition gases within the septic tank (50).
Numerous alterations, modifications, and variations of the preferred embodiments disclosed herein will be apparent to those skilled in the art and they are all anticipated and contemplated to be within the spirit and scope of the instant invention. For example, although specific embodiments have been described in detail, those with skill in the art will understand that the preceding embodiments and variations can be modified to incorporate various types of substitute and or additional or alternative materials, relative arrangement of elements, and dimensional configurations. Accordingly, even though only few variations of the present invention are described herein, it is to be understood that the practice of such additional modifications and variations and the equivalents thereof, are within the spirit and scope of the invention as defined in the following claims. The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or acts for performing the functions in combination with other claimed elements as specifically claimed.
Patent Application
20080011757
