Ulllted States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,806,702
`
`Sabo
`
`[45] Date of Patent:
`
`Sep. 15, 1998
`
`US005806702A
`
`[54] RIBBED STORAGE TANK
`
`Inventor: Stephen A. Sabo, South Bend, Ind.
`[75]
`[73] Assignee: A.K. Industries, Inc., Plymouth, Ind.
`
`[21] Appl. No‘: 908,840
`[22]
`Filedi
`Aug. 3, 1997
`[51]
`Int. cm ..................................................... B651) 25/00
`[52] U.S. Cl.
`......................... 220/412, 220/413; 2,20,/565
`Of Search .....................................
`
`2'0/4'12’ 413
`
`[561
`
`Cited
`u.S_ PATENTD()CU1\,]ENTS
`3/1981 Snyder et al.
`...................... 2'20/673 x
`11/1983 Morris . . . . . . . . . . .
`. . . .. 220/4.13 X
`
`12/1987 Shelton, Jr.
`220/4.12 X
`1/1988 Fons . . . . . . . . . . . . . .
`. . . . .. 220/565 X
`5/1991 Sharp ............................... .. 220/4.12 X
`
`4,g57,527
`4,353,561
`4,715,513
`4,718,208
`5,017,044
`
`Primary ExamirLer—SteVen M. Pollard
`Attorney, Agent, or Firm—Baker & Daniels
`[57]
`ABSTRACT
`
`An underground storage tank for use for Wastewater storage
`Zr as a temporary holldfing tank for ylvalsitewatter cl): runc1)fldfrom
`ramage sys ems.
`e presen
`o mg an
`111C u es a
`generally cylindrical sidewall having aplurality of integrally
`§;jC13f;1ife1r:f;§§;f1n:1b§:f tigngggegjgiiforfilgg ff: Sggfld
`Strengthen the Sigewafl against the Cmsmng forces Ofiydmlf
`Static pressure’ and thus the present tank can be Constructed
`from polyethylene. The bottom of the tank terminates in a
`§Z?§§§3ce§°?$§§o??V§§§sae‘§.l§l§al3?'w‘1licl“‘f§;§§l§£té3°l§“§
`ground support pad. A raised anti-flotation annular collar
`t
`th—t
`d
`’
`f
`th—
`'bd fthtnk
`fiifiargrzienfs a§1:“ta§§“§fO“m“§§ing°
`fiyyfiydrjstfific
`ressure
`P
`‘
`
`33 Claims, 5 Drawing Sheets
`
`=5
`
`xi-1"u
`
`57'?"
`
`Franklin Electric Co., Inc.
`Exhibit 1030
`
`Franklin Electric Co., Inc.
`Exhibit 1030
`
`

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`U.S. Patent
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`Sep. 15, 1998
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`Sheet 1 0f5
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`5,806,702
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`U.S. Patent
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`Sep. 15, 1998
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`Sheet 2 0f5
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`5,806,702
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`-i \_I_IIIIlII
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`J4"!
`-a\.__.
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`9 _b‘
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`.’
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`U.S. Patent
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`Sep. 15, 1998
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`Sheet 3 of 5
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`5,806,702
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`U.S. Patent
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`Sep. 15, 1998
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`Sheet 4 0f5
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`5,806,702
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`U.S. Patent
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`Sep. 15, 1998
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`Sheet 5 0f5
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`5,806,702
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`5,806,702
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`1
`RIBBED STORAGE TANK
`BACKGROUND AND SUMMARY OF THE
`INVENTION
`
`Most sewage treatment systems, storm water collection
`systems, and other drainage systems have a number of
`drainage pipes that transport liquids such as liquid waste,
`storm water or other fluids to a number of storage basins or
`lift stations spaced intermittently throughout the system.
`These storage basins or lift stations are typically buried
`underground, and include an opening having a removable
`access cover to provide access to the interior of the storage
`tank and to any internal mechanical equipment such as
`pumps, filters, couplings, fittings, etc. Such storage tanks or
`basins typically include an input pipe for routing the fluids
`into the basin and an output pipe for routing the fluids out.
`Typically, fluid from the system is routed into the storage
`basin and then pumped out after the level of fluid within the
`basin has reached a predetermined level. Because the storage
`tanks may be empty or nearly empty for extended periods,
`such tanks must be strong enough to Withstand the crushing
`forces of hydrostatic pressure.
`The present invention provides a liquid storage basin or
`tank having a plurality of annular reinforcing ribs which
`strengthen the wall of the storage tank against the crushing
`forces of hydrostatic pressure. The present storage basin also
`includes a raised annular collar adjacent the bottom end of
`the tank which serves as an anti-flotation device,
`thus
`preventing the hydrostatic forces from slowly lifting the
`storage tank out of the ground. The horizontally disposed
`reinforcing ribs are integrally formed in the tank’s sidewall,
`and have a channel shaped cross section which, in addition
`to providing strength, also provide additional resistance to
`floating. The horizontally disposed reinforcing ribs and the
`tank side wall further cooperate to define a number of
`vertically oriented or longitudinal reinforcing ribs, which
`provide both strength against crushing and which also
`provide a generally flat attachment surface for pipe fittings,
`couplings, and other
`internal mechanical equipment.
`Together, the horizontal and vertical ribs and the annular
`collar greatly increase the strength of the tank. Accordingly,
`the tank can be constructed of polyethylene or similar
`materials rather than more expensive fiberglass or metal.
`Moreover, the integral reinforcement eliminates the need for
`internal or external reinforcement.
`
`The bottom portion or base of the tank includes a tapered,
`generally conical portion which terminates in a generally
`flat, truncated surface. The tapered base includes a plurality
`of reinforcing ribs or sections which greatly strengthen the
`bottom portion of the tank against horizontal and vertical
`crushing forces. The shape of the tapered base also provides
`a nesting area for an internal subfloor which mounted inside
`the tank and which provides a mounting surface for pumps,
`gages, and other mechanical equipment. The internal sub-
`floor allows internal equipment
`to be securely mounted
`Without the use of mounting bolts which penetrate the tank
`wall, thus eliminating a potential source of leakage.
`Accordingly, it is an object of this invention to provide an
`improved underground storage tank.
`It
`is another object of this invention to provide an
`improved molded storage tank that has integral reinforcing
`ribs to resist crushing forces.
`A further object of this invention is to provide an under-
`ground storage tank constructed of polyethylene.
`These and other objects of this invention will become
`readily apparent to those skilled in the art upon a reading of
`the following description.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`FIG. 1 is a fragmentary View in perspective of the ribbed
`underground storage tank according to the present invention;
`a portion of the sidewall has been cut away to reveal the
`internal floor insert, a discharge conduit, and other acces-
`sories;
`FIG. 2 is cross-sectional of the present ribbed storage tank
`shown supported on a concrete base and surrounded by dirt,
`gravel, or other backfill;
`FIG. 3 is a fragmentary exploded view in perspective of
`the present ribbed storage tank showing the floor insert, the
`access cover, and equipment for mounting within the tank;
`FIG. 4 is an elevational view of the ribbed storage tank
`shown in FIGS. 1 through 3;
`FIG. 5 is bottom plan view taken along lines 5—5 of FIG.
`4 illustrating the shape of the tapered bottom portion of the
`tank; and
`FIG. 6 is a top plan view taken along lines 6—6 of FIG.
`4 illustrating the removable access cover.
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The embodiment herein described is not intended to be
`
`the invention to the precise form
`exhaustive or to limit
`disclosed. The embodiment described in detail below has
`
`been chosen and described to explain the principles of the
`invention and its application and practical use in order to
`best enable others skilled in the art to follow its teachings.
`Referring now to the drawings, the ribbed underground
`storage basin or
`tank incorporating the features of the
`present invention is generally referred to by the reference
`numeral 10. Tank 10 includes an upper end 12, a lower end
`14, and a generally conical tapered bottom section 16. A
`raised annular collar 18 generally defines the interface
`between lower end 14 and tapered section 16. Tank 10
`includes a generally cylindrical side wall 20, and the diam-
`eter of collar 18 is greater than the diameter of side Wall 20.
`Sidewall 20 includes a plurality of annular ribs 22 which
`are spaced circumferentially about side wall 20 and which
`are separated by a plurality of longitudinal ribs 24 which are
`also spaced circumferentially about side wall 20 and which
`separate annular ribs 22. Each annular rib 22 includes a top
`flange 26, a bottom flange 28 and an interconnecting web 30.
`Similarly, as can be seen in FIG. 4, each longitudinal rib 24
`includes a pair of side flanges 32, 34 and an interconnecting
`Web 36. Web 36 of longitudinal ribs 24 is generally coex-
`tensive with side wall 20. Collar 18 includes a generally
`upwardly facing surface 38, which provides a resting area
`for dirt, gravel or other back fill so that surface 38 and along
`with bottom flanges 28 of annular ribs 22 help to maintain
`tank 10 Within the ground and resist the uplifting forces
`caused by hydrostatic pressure.
`Referring now to FIGS. 3-5, tapered section 16 extends
`from collar 18 and terminates in a generally flat bottom
`support surface 40. As shown to advantage in FIGS. 3 and
`5, bottom section 16 includes a plurality of supporting
`columns or posts 42, each of which has a pair of generally
`planer surfaces 44, 46 separated by a fold or seam 48 which
`adds stiffness to each post 42. Surfaces 44 and 46 of each
`post 42 converge and terminate in a generally triangular
`ground support pad. A plurality of intersecting channel
`shaped ribs 52 separate each post 42, and provide an avenue
`for ground water to flow underneath the ground support
`surface 40. The upper surface of ribs 52 define a floor 54 on
`the interior of tank 10. As shown in FIG. 3, a floor insert 56
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`5,806,702
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`3
`fits inside tank 10 and rests on floor 54. Insert 56 includes
`
`a plurality of angled points 58 and a plurality of indentations
`60. Points 58 engage the inner surfaces posts 42, while
`indentations 60 engage the inner surfaces of ribs 52, which
`serves to lock insert 56 in place and which prevents any
`movement of the insert 56 relative to the tank 10. Insert 56
`
`includes a support surface 62 which serves as an attachment
`point for mounting bracket 65, to which is mounted acces-
`sories such as a pump 64, piping 66, or other accessories
`commonly employed in the art. Support surface 62 of insert
`56 enables the user to firmly attach the accessories within the
`tank 10 without drilling holes through the sidewall 20 or the
`support surface 40, and accordingly a potential source of
`leakage is eliminated. Piping 66 typically must penetrate
`sidewall 20, which is preferably done by drilling a hole
`through the sidewall 20 through the web 36 of one of the
`longitudinal ribs 24. A sealed coupling 67 or similar means
`is typically provided in order to maintain a seal between the
`piping 66 and the sidewall 20. An upper support bracket 68
`includes a central portion 70 and a pair of ends 72, 74. Ends
`72, 74 are sized to engage the inner surface of sidewall 20
`and may be glued, bonded or otherwise secured to sidewall
`20 by commercially available adhesives. Alternatively, ends
`72, 74 may be mounted in between adjacent annular ribs 22
`in a similar manner. A removable access hatch or cover 76
`
`is secured to the top rim 78 using mounting bolts as is
`common industry practice.
`In operation,
`the tank 10 is typically supported on a
`concrete base 80 which has been poured or placed well
`below the ground level 82. The area surrounding the tank 10
`is typically backfilled using pea gravel 84 or similar aggre-
`gate such as sand, dirt, and other materials commonly
`employed in the industry. The downward gravitational force
`of the gravel 84 against the raised collar 18 and the flanges
`28 of ribs 22 prevent the commonly occurring problem of
`hydrostatic lift-ofi“. Insert 56 is placed within the tank 10
`adjacent the tapered bottom section 16, with the points 58 in
`engagement with the inner surfaces posts 42 and with the
`indentations 60 in engagement with the inner surfaces of ribs
`52. Mounting bracket 65 as well as the pump 64 and piping
`66 can be secured to insert 56 either before or after insert 56
`
`is positioned within tank 10. After bracket 68 has been
`secured, cover 76 is secured to the top of tank 10, thus
`sealing the tank and securing the contents.
`It is understood that the above description does not limit
`the invention to the above-given details, but may be modi-
`fied within the scope of the following claims.
`What is claimed:
`
`1. An underground storage tank for placement in the
`ground for receiving, temporarily holding, and discharging
`effluent, said tank comprising:
`a top end, a bottom end, and a generally cylindrical
`interconnecting sidewall, said sidewall including a plu-
`rality of annular ribs integrally formed into said
`sidewall, said sidewall and said annular ribs defining a
`plurality of longitudinal ribs spaced circumferentially
`about said sidewall;
`a tapered portion extending from said bottom end, said
`tapered portion being separated from said sidewall by
`a raised annular collar, the diameter of said collar being
`greater than the diameter of said sidewall;
`said tapered portion terminating in a ground support
`surface, said tapered portion further including a plural-
`ity of base ribs; and
`a fioor insert having an equipment mounting surface for
`placement
`inside said tank adjacent said tapered
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`portion, said insert engaging and interlocking with a
`portion of said tapered portion to thereby support said
`insert at a distance spaced from said ground support
`surface to permit accessories to be mounted to said
`insert without drilling holes through said tank.
`2. The tank as claimed in claim 1, wherein a portion of
`said sidewall defines an attachment surface to permit the
`attachment of accessories to said sidewall.
`3. The tank as claimed in claim 1, wherein a portion of at
`least one of said longitudinal ribs defines an attachment
`surface to permit
`the attachment of accessories to said
`sidewall.
`4. The tank as claimed in claim 1, wherein said annular
`ribs include top and bottom flanges and an interconnecting
`web.
`5. The tank as claimed in claim 1, wherein said longitu-
`dinal ribs include a pair of side flanges and an interconnect-
`ing side web.
`6. The tank as claimed in claim 1, wherein said longitu-
`dinal ribs include a web, said longitudinal rib web being
`generally coextensive with said sidewall.
`7. The tank as claimed in claim 1, wherein said annular
`ribs protrude inwardly from said sidewall.
`8. The tank as claimed in claim 7, wherein said annular
`ribs include a web and a pair of flanges, said annular rib
`flanges and said annular collar defining anchor means for
`anchoring said tank in the ground.
`9. The tank as claimed in claim 1, wherein said annular
`ribs are spaced circumferentially about said sidewall.
`10. The tank as claimed in claim 1, wherein said tapered
`portion includes a plurality of inclined support posts, and
`said ground support surface includes a plurality of ground
`support pads, each of said support posts terminating in a said
`ground support pad.
`11. The tank as claimed in claim 10, wherein said support
`posts extend between said annular collar and said ground
`support surface.
`12. The tank as claimed in claim 11, wherein each of said
`support posts include a pair of generally outwardly facing
`planar surfaces, said planar surfaces being separated by a
`reinforcing seam.
`13. The tank as claimed in claim 10, wherein said support
`posts taper with distance towards said ground support sur-
`face.
`14. The tank as claimed in claim 10, wherein each of said
`ground support pads is triangular.
`15. The tank as claimed in claim 10, wherein said ground
`support surface includes a plurality of base ribs, each of said
`pads being separated one of said base ribs.
`16. A molded underground storage tank for placement in
`the ground for receiving, temporarily holding, and discharg-
`ing efiluent, said tank comprising:
`a top end, a bottom end, and a generally cylindrical
`interconnecting sidewall, said sidewall including a plu-
`rality of annular
`ribs integrally formed into said
`sidewall, said sidewall and said annular ribs defining a
`plurality of longitudinal ribs spaced circumferentially
`about said sidewall;
`a tapered portion extending from said bottom end, said
`tapered portion being separated from said sidewall by
`a raised annular collar, the diameter of said collar being
`greater than the diameter of said sidewall;
`said tapered portion terminating in a ground support
`surface, said tapered portion further including a plural-
`ity of base ribs; and
`ground anchor means for anchoring said tank in the
`ground, said means being integrally molded into said
`sidewall.
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`5,806,702
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`5
`17. The tank as claimed in claim 16, including mounting
`means for mounting accessories to the interior of said tank,
`said mounting means permitting accessories to be mounted
`to said tank without drilling holes through said tank.
`18. The tank as claimed in claim 17, said mounting means
`including a floor insert, said floor insert for placement inside
`said tank adjacent said tapered portion, said insert being
`adapted to engage and interlocking with a portion of said
`tapered portion to thereby support said insert at a distance
`spaced from said ground support surface.
`19. The tank as claimed in claim 16, wherein a portion of
`said sidewall defines an attachment surface to permit the
`attachment of accessories to said sidewall.
`
`20. The tank as claimed in claim 16, wherein a portion of
`at least one of said longitudinal ribs defines an attachment
`surface to permit
`the attachment of accessories to said
`sidewall.
`21. The tank as claimed in claim 16, wherein said annular
`ribs include top and bottom flanges and an interconnecting
`web.
`
`22. The tank as claimed in claim 16, wherein said longi-
`tudinal ribs include a pair of side flanges and an intercon-
`necting side web.
`23. The tank as claimed in claim 16, wherein said longi-
`tudinal ribs include a web, said longitudinal rib web being
`generally coextensive with said sidewall.
`24. The tank as claimed in claim 16, wherein said annular
`ribs protrude inwardly from said sidewall.
`
`6
`25. The tank as claimed in claim 24, wherein said ground
`anchor means includes an annular collar.
`26. The tank as claimed in claim 25, wherein said annular
`ribs include a web and a pair of flanges, said ground anchor
`means further includes said annular rib flanges.
`27. The tank as claimed in claim 16, wherein said annular
`ribs are spaced circumferentially about said sidewall.
`28. The tank as claimed in claim 16, wherein said tapered
`portion includes a plurality of inclined support posts, and
`said ground support surface includes a plurality of ground
`support pads, each of said support posts terminating in a said
`ground support pad.
`29. The tank as claimed in claim 28, wherein said support
`posts extend between said annular collar and said ground
`support surface.
`30. The tank as claimed in claim 29, wherein each of said
`support posts include a pair of generally outwardly facing
`planar surfaces, said planar surfaces being separated by a
`reinforcing seam.
`31. The tank as claimed in claim 28, wherein said support
`posts taper with distance towards said ground support sur-
`face.
`32. The tank as claimed in claim 28, wherein each of said
`ground support pads is triangular.
`33. The tank as claimed in claim 28, wherein said ground
`support surface includes a plurality of base ribs, each of said
`pads being separated one of said base ribs.
`
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