`
`1191
`
`1111 Patent Number:
`
`6,059,208
`
`Struthers
`
`[45] Date of Patent:
`
`May 9, 2000
`
`US006059208A
`
`4,014,475
`4,255,909
`4,339,231
`4,345,996
`
`..
`3/1977 Grace et al.
`3/1981 Séderstrém .... ..
`7/1932 C0381)’ 91 a1~
`8/1982 Lindman et al.
`
`.
`
`.. 241/36
`52/20
`~~~~ ~ 417/40
`210/96.1
`
`
`
`...................... .. 137/584
`12/1987 Sidaway et al.
`4,709,723
`........................ .. 141/86
`4,793,387 12/1988 LeBlanc et al.
`4,822,213
`4/1989 G ,
`t
`l.
`.... ..
`405/303
`4,867,871
`9/1989 B(r):::e.e..............
`...... 210/97
`4,919,343
`4/1990 Van Luik, .11’. et al.
`241/36
`5,038,817
`8/1991 Henry etal.
`............................ 137/315
`5
`.
`’
`'
`l.
`.............................. ..
`5
`5;3::;2::
`2/123: 1:;::;:: ,,,,,..
`N 241/36
`‘
`$439,180
`8/-1995 Baughman et a1.
`-~34
`§1e1::n::1‘*e1N1~l~-~~~~~
`5:816:510 10/1998 Earle, H1 at ,1‘
`.................. N 241,460,
`
`Primary Exrzminer—John M Husar
`Attorney, Agent, or Firm—Seidel, Gonda, Lavorgna &
`Monaco, PC
`_
`[57]
`
`ABSTRACT
`
`An integrally molded plastic sump basin formed with two
`distinct porn-ODS including a Constant depth’ Shallow dry
`well at. the top defining a controls area that 1S isolated ‘from
`a varying depth wet well below, said wet well defining 21
`pump chamber. Allelectronic controls,‘ level sensor controls
`and valve extension control are situated in the non-
`hazardous dry well while pump(s) and associated piping are
`contained within the potentially hazardous wet well part of
`the basin. The sump basin may be formed with a drop inlet
`opening for sewage entry that enhances installation flexibil-
`ity and provides more eificient processing of sewage enter-
`mg the basin
`‘
`
`19 Claims, 5 Drawing Sheets
`
`Franklin Electric Co., Inc.
`Exhibit 1007
`
`[54] BURIED PLASTIC SEWAGE SUMP
`
`[75]
`
`Inventor: Kevin D. Struthers, Coatesville, Pa.
`
`[73] Assignee.
`
`Interon Corporation, Exmn, Pa‘
`
`1221
`
`[21] ApP1~N0~I 09/150,563
`4.
`.
`S9910’ 1998
`I“1"d"
`
`
`,
`Provisional application No. 60/058,613, Sep. 11, 1997.
`[60]
`Int. Cl.7 ..................................................... B02C 18/40
`[51]
`[52] U.S.Cl. .....................................241/46.01;241/46.62;
`241/285.1
`
`[58] Field of Search .......................... .. 241/46.01, 46.017,
`241/46.02, 46.06, 46.11, DIG. 38, 285.1
`
`[56]
`
`References Cited
`US. PATENT DOCUMENTS
`
`,
`’
`g
`78/1974 Grace ...................................... .. 241/36
`Re. 28,104
`12/1941 Halt
`103/119
`2,267,459
`6/1950 Bymm .
`N 103/118
`2,512;764
`12/1963 Budd
`137/363
`3,112}./.60
`. ... .._ ..
`6/1968 Wyatt
`. ._N 174/37
`3,390,224
`6/1968 Couch et a1.
`174/37
`3,390,225
`8/1969 stothoff, 111 61 a1,
`103/25
`3,451,303
`5/1972 Stigberg ..
`.. 417/566
`3,664,775
`6/1972 Grace ~ ~ - ~ ~ ~
`~ ~ ~ ~~ 241/36
`3,667,692
`5/1973 Park“ ------ ~-
`- 299/81 R
`3:733/149
`33577517 12/1974 Grace 61 91‘
`241/36
`3,858,813
`1/1975 Hiller ................................... 241/46.02
`3,904,131
`9/1975 Farrell, Jr. et al.
`................ .. 241/46.02
`3,938,744
`2/1976 Allen ................ ..
`241/46.11
`
`3,999,890 12/1976 Niedermeyer ........................... .. 417/17
`
`
`
`Franklin Electric Co., Inc.
`Exhibit 1007
`
`
`
`U.S. Patent
`
`May 9, 2000
`
`Sheet 1 of 5
`
`6,059,208
`
`81
`
`0
`
`33
`
`‘/‘i
`
`20
`
`
`
`.M..I%.,.,,,r_..,,/,
`
`23x
`
`3W22210763
`
`1|.
`
`533222
`
`
`
`
`
`U.S. Patent
`
`May 9, 2000
`
`Sheet 2 of 5
`
`6,059,208
`
`FIG. 2
`
`
`
`U.S. Patent
`
`May 9, 2000
`
`Sheet 3 of 5
`
`6,059,208
`
`FIG. 3
`
`
`
`U.S. Patent
`
`May 9, 2000
`
`Sheet 4 of 5
`
`6,059,208
`
`
`
`U.S. Patent
`
`May 9, 2000
`
`Sheet 5 of 5
`
`6,059,208
`
`
`
`6,059,208
`
`1
`BURIED PLASTIC SEWAGE SUMP
`
`This application claims priority from provisional appli-
`cation Ser. No. 60/058,613 filed Sep. 11, 1997.
`FIELD OF THE INVENTION
`
`This invention relates to an underground sump basin and
`more particularly a sewage sump basin where sewage enters
`the basin from a home or facility, is ground up by a sewage
`grinder pump to a fine slurry, and then pumped under low
`pressure to a waste treatment facility or a gravity collection
`system elsewhere.
`BACKGROUND OF THE INVENTION
`
`The concept of a wet well/dry well combination in a
`common structure is not novel. Dry wells are usually large
`areas that permit the entrance of a person to work on the
`components of a pumping system. Dry wells can be located
`at a fixed distance from the bottom of the sump where a
`pump is suspended through the floor of the dry well into the
`wet well below, hanging a given distance off of the bottom
`of the wet well. A deeper dry well is created as the depth of
`the basin increases due to such factors as the depth of the
`frostline. With today’s ‘confined space’ work safety require-
`ments and concerns with toxic fumes, the need to prevent
`unnecessary confined space entry and exposure to poten-
`tially hazardous environments is a major area of public
`interest and potential legal liability. It is well known that
`persons have been overcome by toxic fumes working in wet
`well environments, some with fatal consequences.
`A typical basin for this sewage application is made from
`fiberglass or polyethylene and is simply a wet well, with
`electrical junction boxes located inside the basin and a
`control panel located on the outside surface. Most pumping
`stations use mechanical floats as fluid level controls, which
`have a tendency to malfunction either because they become
`fouled with grease, wedged stuck or tangled with other
`equipment. The floats require regular maintenance.
`One prior embodiment of a residential sewage pumping
`system uses a wet well/dry well basin design.
`In this
`embodiment,
`the pump is bolted through a center shelf
`located at a fixed distance from the bottom so that the pump
`is suspended off the bottom.
`In order to accommodate
`different requirements for burial depth, extensions are
`added,
`increasing the depth of the dry well. A person
`servicing this type of system may be required to work inside
`the dry well to unbolt the pump and lift it up. As soon as the
`pump is removed, the dry well technically becomes part of
`the wet well, as there is nothing separating the two cham-
`bers. This becomes more of a problem when a person must
`reposition the pump onto the center shelf and bolt it back
`into place. Another problem with this particular system is the
`inability to physically watch the pump and level controller
`functioning.
`Another potential problem with buried sewage sumps is
`the typically rigid piping-to-sump connection, which can be
`exposed to some large shear stresses as the basin shifts in the
`ground due to back filling, basin settling and/or hydrostatic
`lifting forces.
`Many pumping system basins use a guide rail system for
`positioning the pump and holding it in place. The guide rails
`are typically bolted through the wall of the basin, which can
`act as a weak point for failure of the basin wall or for the
`development of future leaks.
`SUMMARY OF THE INVENTION
`
`10
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`2
`wet well. The dry well is typically no deeper than about eight
`inches measured from the top of the sewage sump basin,
`though its depth may vary to accommodate control devices
`and electronics. Asecond lid over an aperture in the floor of
`the dry well isolates the potentially hazardous environment
`of the wet well from the shallow dry well. All of the
`electrical and sensor connections are made in the shallow
`dry well where they can be serviced without exposure to
`whatever effluent there might be in the wet well.
`In a preferred embodiment of the invention, the plastic
`sewage sump basin employs ultrasonic level sensing, which
`is accomplished by a sensor mounted through the bottom of
`the dry well. This non-contact method of level sensing
`further prevents exposure to the contents of the sewage
`sump, which tend to grease, clog and foul other level sensing
`devices such as floats and pressure switches.
`A ball valve that closes the outlet pipe is also operated
`from within the dry well portion of the sump basin. The only
`occasion to lift
`the inner lid in the dry well, creating
`exposure to the effluent, is to permit removal of the pump.
`The pump in the sump basin of the present invention is
`suspended off the bottom, held in a ‘C’ channel guide rail,
`and fitted with a ‘quick disconnect’ fitting. Aplastic coated,
`stainless steel cable used to lift the pump is positioned at the
`top of the C-channel rail directly under the inner lid of the
`dry well.
`The invention also features the use of an integrally
`molded-in reverse boss for the purpose of protecting exter-
`nal discharge piping connections from vertical shear forces.
`The piping joint made in the boss is protected from the shear
`forces of the ground by the vertical walls of the basin as it
`is back filled, where there may be position shifts of the pipe
`or the sump due to settling or the hydrostatic forces of a high
`water table.
`
`One embodiment of the present invention further features
`the use of a basin with an integrally molded-in cup into
`which the C-channel rail is anchored without having to use
`bolt penetrations through the basin wall or floor. An alter-
`native embodiment features a molded reverse boss in the
`
`bottom of the basin which creates a raised shape on the
`inside of the wet well. The bottom of the C-channel rail fits
`
`the purpose of seating the
`the raised shape for
`over
`C-channel rail on the bottom of the wet well without having
`to use bolt penetrations through the basin floor.
`The present invention comprises a sewage grinder pump
`basin assembly comprising a molded plastic sewage sump,
`said sump being an integrally molded basin having a dry
`well area and a wet well area below the dry well and
`separated from it by a floor in the dry well, said floor having
`an opening over which a lid is removably seated, a grinder
`pump located in the wet well area for grinding sewage and
`pumping it out through a discharge pipe, and a lid removably
`attached to the sump covering the dry well area. The dry well
`area contains equipment comprising an electrical junction
`and control box, a remote shut-off handle for a valve
`controlling sewage output from the basin, and a level sensor.
`The dry well area has a shallow depth limited to that depth
`necessary to house the equipment. The opening in the dry
`well floor providing access to the wet well area below.
`The wet well area contains a C-channel rail extending
`downwards from the dry well floor to the bottom of the wet
`well, a plumbing tree connected at a first end to the grinder
`pump and at a second end to a quick-disconnect fitting
`located in the C-channel rail, said grinder pump being
`located near the bottom of the wet well area.
`
`The present invention provides the benefit of a shallow
`dry well integrally molded with a sewage grinder basin and
`
`The molded plastic sump further comprises a drop inlet
`molded into the wet well area of the sump as an outward
`
`
`
`6,059,208
`
`3
`projection of a side wall of the wet well, said drop inlet
`comprising a substantially horizontal outward projection
`from a side wall of the sump, said horizontal projection
`having an inlet opening provided for sewage inlet from
`above, said drop inlet further comprising a curved bottom
`wall for directing inlet sewage dropped through the inlet
`opening directly to the grinder pump in the bottom of the wet
`well, said molded drop inlet being connectable from direc-
`tions varying over 180° with respect
`to the drop inlet
`opening.
`The sump comprises a reverse boss molded into the side
`wall
`to provide a location for a pipe joint where the
`discharge pipe joins the sewage sump that is protected from
`direct underground stress caused by shifting of the sump or
`the surrounding soil.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`there are
`For the purpose of illustrating the invention,
`shown in the drawings forms which are presently preferred;
`it being understood however,
`that
`this invention is not
`limited to the precise arrangements and instrumentalities
`shown.
`
`FIG. 1 is a cut-away perspective view of the sewage basin
`along with all the components of the complete system.
`FIG. 2 is a vertical cross section of the basin showing the
`pertinent components of the sewage basin.
`FIG. 3 is a vertical cross section of an extended basin
`
`showing how the dry well remains a fixed depth from the top
`in deeper basins.
`FIG. 4 is a vertical cross-section view of a second
`
`embodiment of the sewage basin.
`FIG. 5 is a top plan view of the embodiment illustrated in
`FIG. 4.
`
`DESCRIPTION OF THE INVENTION
`
`Referring to FIG. 1, a molded plastic basin 10 comprising
`an upper dry well area 11 and lower wet well area 12 is
`illustrated. The upper dry well area 11 is isolated from the
`lower wet well 12 by a floor 9 (FIG. 2) having an opening
`over which a molded plastic lid 13 is sealed with a rubber
`gasket 14. The gasket 14 is adhered to a raised lip 15. A
`molded nylon lid 16 is fastened to the basin 10 by means of
`stainless steel bolts 17 which screw into molded-in T-nuts 18
`
`at the top of the basin 10. A rubber gasket 19 is fitted into
`a shallow channel along the top edge of the basin 10 to make
`a water—tight seal. Inside the dry well 11 is an electrical
`junction box 20, an ultrasonic level sensor 21 and a remote
`handle 22 for control of a shut off valve.
`
`The dry well 11 need only be deep enough to house the
`equipment
`located within it.
`In the presently preferred
`embodiment of the sump, the dry well can be about eight
`inches deep and easily contain the junction box, level sensor
`element, and shut-off valve handle. A significant feature of
`the dry well is that it is shallow; it is only deep enough to
`house the necessary equipment elements in a dry well
`isolated from the wet well. The dry well cannot be entered
`or occupied by a service technician, nor need it be. The dry
`well 11 is accessed by removing the lid 16 from the basin
`and reaching arms and hands into the dry well to service the
`equipment, not by physically entering the dry well space.
`The electrical junction box 20 houses both the electrical
`connections for the equipment in the sump basin 10 and the
`controls for operating the equipment. Among the latter are
`status indicator lights for the power, the grinder pump and
`level sensor, a manual override control, circuit breakers, and
`
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`data connections. Because the junction box 20 is housed
`inside the basin rather than outside,
`the electrical
`connections, service connections and status indicators are all
`protected from the elements and easily accessed from above
`for service. It is possible, however, to locate the equipment
`controls, data connections and indicator lights in a separate
`enclosure within the dry well, isolating them from the power
`connections.
`
`It is important in equipment that will be buried in the
`ground to protect any and all metallic hardware from expo-
`sure to the corrosive effects of the underground
`environment, particularly ground water and earth minerals.
`That is why all of the equipment for operating and servicing
`the grinder pump basin is contained within the basin. None
`remains outside; even the electrical power connections are
`made inside the basin.
`
`the level
`In a preferred embodiment of the invention,
`sensor employed is an ultrasonic device that detects the level
`of elfluent in the basin by bouncing sound waves off the
`surface of the effluent. This non—contact method of level
`
`sensing has advantages over mechanical means, which can
`stick, become fouled with grease and sludge, or deteriorate
`in contact with sewage. Other forms of non-Contact sensors
`may also be employed within the scope of the invention.
`These may include infrared, laser or other photonic distance
`measuring devices, electro—optical and sonic distance detec-
`tors.
`
`A water-tight lid 16 bolts down onto the top of the basin
`10 with a rubber gasket 19 between basin 10 and lid 16. The
`T-nuts 18 that engage the stainless steel bolts 17 are molded
`into the rim of the basin 10 when the basin is fabricated. The
`
`T-nuts are locked into the plastic of the rim during the
`molding process, sealed from weather, ground water and
`sewage.
`Aplastic C—channel guide rail 23 is bolted to the lip 15 of
`the dry well access way and extends down to the bottom of
`the wet well 12 into an integrally molded-in cup 24. The
`bottom of the C—channel rail 23 is fitted with a rubber boot
`
`25 to create a tight friction fit for the C—channel rail 23 into
`the cup 24 and prevent wear on the molded-in plastic cup 24.
`A stop 26 is mounted into the C—channel rail 23 which acts
`to position a quick-disconnect fitting 27 in line with the
`discharge piping 33 and to suspend the pump 28 above the
`bottom of the basin 10. The dimension of the quick discon-
`nect fitting 27 is selected with sufficient tolerance to be
`located in the C—channel rail 23 and fit between a rubber seal
`
`in the quick disconnect fitting 27 and the corresponding
`flanged face of the discharge fitting 29. (See FIG. 2.)
`The flanged discharge fitting 29 is threaded through the
`C—channel rail 23 and secured in place with a lock nut (not
`shown). The flanged discharge fitting 29 is joined by a shaft
`52 to a close-off ball valve fitting 30 which has a remote
`handle 22 located in the dry well 11 where the valve can be
`opened and closed without entering the wet well 12. The ball
`valve is fitted with a short pipe stub 31 that penetrates
`through the wall of the basin 10 at a reverse boss 32 (FIG.
`2). The reverse boss 32 protects the connection of the
`flexible discharge pipe 33 to the pipe stub 31 from vertical
`shear forces of the ground.
`The quick disconnect fitting 27 is attached to the pump 28
`by means of a plumbing tree 34 which includes a check
`valve 35. The pump 28 is further held in position by a
`standolf fitting 37 designed to be captured in the arms of the
`C—channel rail 23. The pump 28 is wired with a quick
`disconnect plug 38 to make pump change-out a safe and fast
`operation. The pump 28, the quick disconnect fitting 27 and
`
`
`
`6,059,208
`
`5
`the whole plumbing tree 34 may be pulled out as one piece
`by means of a plastic-coated stainless steel cable 39 which
`is fitted with a plastic handle 40 made to friction fit into the
`top of the C-channel rail 23.
`The penetrations through the basin 10 wall for the sewage
`inlet pipe 41, the Vent pipe 42 and the discharge pipe 31 are
`all sealed with compression seal gaskets 43 that create a
`water tight seal while still allowing the respective pipes to
`deflect. The flexible pipe joint between the discharge pipe 33
`and pipe stub 31 uses a PVC coupling swage (not shown)
`fitted to the flexible polyethylene pipe. These are full bore
`connections that do not inhibit the flow of effluent out of the
`tank. The PVC coupling can be glued to any solvent-
`weldable pipe being used for the collection piping system.
`This combination mechanical/glue connection can be used
`to join normally incompatible piping systems so that benefits
`of dissimilar systems can be combined for the best complete
`system.
`Electrical conduit 45 is used to bring a power cable into
`the basin 10, deliver it to the dry well 11, and take a sensor
`cable (not shown) from the dry well 11 to a monitor located
`nearby (such as in a house or other facility served by the
`sump). The monitor allows a homeowner/facility manager to
`know if the sewage pump is operating normally, and indi-
`cates an alarm condition in the event of a problem.
`FIG. 2 shows a cross section of a short standard basin 10
`
`where the dry well 11 is separated from the wet well 12. This
`drawing also shows in detail
`the discharge piping
`connection, and in particular the reverse boss 32. The
`discharge pipe stub 31 attached to the ball valve 30 passes
`through the wall of the basin into the reverse boss 32. The
`discharge pipe stub 31 terminates within the depression of
`the boss 32 so that its connection to the plastic coupling 44
`and discharge pipe 33 is made within the boss 32. The
`connection of the discharge pipe 33 to the plastic coupling
`44 completes the discharge path out of the sewage sump.
`Also shown in FIG. 2 is the flanged discharge fitting 29 and
`the compression seal gasket 43. The integrally molded-in
`cup 24 is shown with the rubber boot 25 and the C-channel
`rail 23.
`FIG. 3 is a cross section of a basin 10 with a riser section
`
`54 welded by ajoint 50 to the standard base section to extend
`the depth of the basin as may be required in cold-weather
`areas with deeper frost
`lines. The dry well 11 remains
`located in the top of the riser 54 while the depth of the wet
`well 12 is extended upwards. The depth of the shallow dry
`well 11 remains the same.
`
`In a presently preferred embodiment of the invention, the
`plastic basin 10 is molded of high density polyethylene
`(HDPE), which provides both structural strength and mate-
`rial compatibility with most sewage components such that
`the basin will not deteriorate by reacting with the contents.
`Other forms of plastic may be used where conditions dictate,
`depending upon the structural characteristic that may be
`most important in a given application.
`Referring to FIG. 4, another embodiment of the sump,
`sewage enters the sump at a drop inlet 59 instead of directly
`through the side wall of the sump (as shown in FIG. 1).
`There is a functional advantage to having a drop inlet
`sewage entry. Sewage entering the sump is naturally directed
`toward the grinder pump 28 because of the sloped bottom 61
`just beneath the drop inlet 59. The immediate channeling of
`sewage to the grinder pump helps ensure the quick and
`thorough grinding of sewage solids into a more homogenous
`slurry to be pumped out of the sump chamber.
`In the drop inlet form of the sump, the basin 74 comprises
`a shelf 60 that extends away from the sidewall of the unit and
`
`6
`alfords a sufliciently large surface in which to place an inlet
`opening 62 that provides a portal for the entry of sewage into
`the basin 74 from the sewage inlet pipe 64. In order that the
`junction of the sewage inlet pipe 64 with the sump basin 74
`is liquid-tight, a grommet 68 is fitted to the inlet opening 62
`in the shelf 60. The grommet fits about a coupling 66 into
`which the inlet pipe 64 is inserted and sealed. Other instru-
`mentalities than a grommet and coupling may be used to
`connect the inlet pipe 64 to the sump inlet opening 62 in a
`liquid-tight manner; the important thing is that the connec-
`tion is not prone to leak, particularly if (when) the sewage
`slurry in the sump rises to a level in the basin that exceeds
`the height of the inlet 62 above the bottom of the basin.
`A major benefit derived from the inclusion of the drop
`inlet sewage entry in a sump according to the invention is the
`latitude that the drop inlet affords for the angle of approach
`and entry of a sewage line into the sump. In the form
`illustrated in FIG. 1, having a simple straight through entry
`in the sump side wall,
`the sewage inlet pipe 41 must
`approach the sump basin 10 approximately perpendicular to
`the side wall. The installed sump basin must have its entry
`side turned toward the direction from which the inlet pipe
`approaches the sump. This may not be a problem in many
`installations and the side inlet sump will be the appropriate
`choice.
`
`But the drop inlet form illustrated in FIG. 4 alfords a range
`of direction up to between 180° to 270° from which the
`sewage supply pipe 69 may approach the sump basin 74. See
`FIG. 5, wherein the shadowed lines indicate the range of
`angles in which the sewage supply pipe 69 may approach the
`sump basin 10 and connect
`to the drop inlet 59. This
`enhances the flexibility available to the site planner when
`locating the sewage sump in relation to the building(s) to be
`served by it. This is particularly so where the sewage
`discharge pipe 33 is flexible and can be routed away from the
`sewage sump in nearly any direction.
`Another degree of freedom and versatility provided by the
`drop inlet form of the sump is adjustment of the depth below
`ground that the sewage entry connection into the sump may
`be made. Referring again to FIG. 4, it can be seen that the
`length of the sewage inlet pipe 64 can be varied below the
`right angle joint 67,
`thereby changing the height of the
`connection between the sewage supply pipe 69 and the
`sewage inlet pipe 64.
`In older sumps where the sewage supply pipe enters on
`the perpendicular directly into a fixed entry inlet in the side
`wall of the sump, in order to change the height of the entry
`point to accommodate the depth of the sewage supply pipe
`the entire sump had to be positioned higher or lower in the
`ground. Where the sewage pipe entry had to be particularly
`deep, a riser would have to be added to the sump basin to
`extend it up to near grade level; in other cases the sump
`height might have to be cut down. In the present invention,
`the drop inlet permits changing the height of the connection
`to the sewage supply pipe without changing the burial depth
`of the sump itself and without making height adjustments in
`the physical configuration of the sump basin.
`The sewage basin of FIG. 4 also illustrates an alternative
`embodiment of the anchoring structure for the C-channel at
`the bottom of the wet well. A reverse boss may be molded
`into the bottom of the plastic basin 74, which creates a raised
`shape 70 on the inside of the basin. The shape may be
`circular, square or another common form. In a presently
`preferred form, the raised shape 70 is triangular. The raised
`shape 70 serves as an anchor point for the C-channel. The
`C-channel 72 fits over the raised shape 70, with one point on
`
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`the raised triangle shape contacting the rear of the channel
`and the other two points contacting the front (open side) of
`the channel on either side of the opening in the “C”. This
`connection provides a stable bottom anchor point for the
`C-channel rail without the use of penetration connectors
`such as screws, bolts and nuts, or rivets.
`The present invention may be embodied in other specific
`forms without departing from the spirit or essential attributes
`thereof and, accordingly, reference should be made to the
`appended claims, rather than to the foregoing specification,
`as indicating the scope of the invention.
`What is claimed is:
`
`1. A sewage grinder pump basin assembly comprising:
`a molded plastic sewage sump, said sump being an
`integrally molded basin having a dry well area and a
`wet well area below the dry well and separated from it
`by a floor in the dry well, said floor having an opening
`over which a lid is removably seated, a grinder pump
`located in the wet well area for grinding sewage and
`pumping it out through a discharge pipe, and a lid
`removably attached to the sump covering the dry well
`area,
`
`said molded plastic sump further comprising a drop inlet
`molded into the wet well area of the sump as an
`outward projection of a side wall of the wet well, said
`drop inlet comprising a substantially horizontal out-
`ward projection from a side wall of the sump, said
`horizontal projection having an inlet opening provided
`for sewage inlet from above, said drop inlet further
`comprising a bottom wall shaped for directing inlet
`sewage dropped through the inlet opening directly to
`the grinder pump in the bottom of the wet well, said
`molded drop inlet being connectible from directions
`ranging to over 180° with respect to the drop inlet
`opening.
`2. The sewage grinder pump basin of claim 1, wherein the
`drop inlet provides variable height adjustment for connec-
`tion of sewage inlet pipes carrying sewage to the basin.
`3. The sewage sump of claim 1, further comprising:
`a reverse boss in the basin wall in which a pipe connection
`may be made that is shielded from shear forces on the
`pipe.
`4. A sewage grinder pump basin assembly comprising:
`a molded plastic sewage sump, said sump being an
`integrally molded basin having a dry well area and a
`wet well area below the dry well and separated from it
`by a floor in the dry well, said floor having an opening
`over which a lid is removably seated, a grinder pump
`located in the wet well area for grinding sewage and
`pumping it out through a discharge pipe, and a lid
`removably attached to the sump covering the dry well
`area,
`
`said dry well area containing equipment comprising an
`electrical junction box, a remote shut-off control for a
`valve controlling sewage output from the basin, and a
`level sensor,
`said dry well area having a shallow depth limited to that
`depth necessary to house the equipment, the opening in
`the dry well floor providing access to the wet well area
`below;
`said wet well area containing a C-channel rail extending
`downwards from the dry well floor to the bottom of the
`wet well, a plumbing tree connected at a first end to the
`grinder pump and at a second end to a quick—disconnect
`fitting located in the C-channel rail, said grinder pump
`being located near the bottom of the wet well area;
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`said molded plastic sump further comprising a drop inlet
`molded into the wet well area of the sump as an
`outward projection of a side wall of the wet well, said
`drop inlet comprising a substantially horizontal out-
`ward projection from a side wall of the sump, said
`horizontal projection having an inlet opening provided
`for sewage inlet from above, said drop inlet further
`comprising a bottom wall shaped for directing inlet
`sewage dropped through the inlet opening directly to
`the grinder pump in the bottom of the wet well, said
`molded drop inlet being connectible from directions
`ranging to over 180° with respect to the drop inlet
`opening.
`5. The sewage sump of claim 4, wherein the electrical
`junction box houses controls and status indicators for the
`equipment in the wet well of the sump.
`6. The sewage sump of claim 4, wherein the molded
`plastic sump comprises a reverse boss molded into the side
`wall
`to provide a location for a pipe joint where the
`discharge pipe joins the sewage sump that is protected from
`direct underground stress caused by shifting of the sump or
`the surrounding soil.
`7. A sump for a sewage grinding pump, comprising:
`a molded plastic basin including a drop inlet attached to
`a lower portion of the basin and projecting outward
`therefrom, said drop inlet comprising a substantially
`horizontal outward projection from a side wall of the
`basin, said horizontal projection having an inlet open-
`ing provided for inlet of sewage from above, said drop
`inlet further comprising a bottom wall shaped for
`directing inlet sewage dropped through the inlet open-
`ing directly to a grinding pump located adjacent the
`bottom of the basin, said molded drop inlet being
`connectible from directions ranging to over 180° with
`respect to the drop inlet opening.
`8. The sump of claim 7 wherein the basin further com-
`prises a dry well and a wet well below the dry well and
`separated from the dry well by a fioor in the dry well, said
`floor having an opening over which a lid is removably
`seated, the lid being removable attached to the sump cov-
`ering the dry well area.
`9. The sump of claim 8 further comprising a grinder pump
`located in the wet well area for grinding sewage and
`pumping it out through a discharge pipe.
`10. The sump of claim 9 wherein the wet well contains a
`C-channel rail extending downward from the dry well floor
`to the bottom of the wet well, a plumbing tree connected at
`a first end to the grinder pump and at a second end to a
`quick-disconnect fitting located in the C-channel rail, said
`grinder pump being located near the bottom of the wet well.
`11. The sump of claim 8 wherein said dry well contains
`equipment comprising an electrical junction box, a remote
`shut-off control for a valve controlling sewage output from
`the basin and a level sensor.
`
`12. The sump of claim 11 wherein said dry well has a
`shallow depth limited to that depth necessary to house the
`equipment,
`the opening in the dry well floor providing
`access to the wet well below.
`
`13. The sump of claim 7 further comprising a reverse boss
`in the basin wall in which a pipe connection may be made
`that is shielded from shear forces on the pipe.
`14. A sump for a sewage grinding pump, comprising:
`a molded plastic basin having an outer wall that partially
`defines the interior of the basin; and
`a reverse boss for receiving a flexible pipe therethrough,
`the reverse boss having a side wall and an end wall, the
`side and end walls defining a depression projecting into
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`the interior of the basin, the side Wall attached at one
`end to the outer wall of the basin and at the opposite end
`to the end Wall,
`the end Wall having an aperture
`therethrough for receiving the pipe.
`15. The sump of claim 14 wherein the reverse boss is
`molded integrally with the outer wall of the basin.
`16. The sump of claim 14 further comprising a compres-
`sion seal gasket located in the aperture between the end Wall
`of the reverse boss and the Wall of a pipe located there- 10
`through.
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`17. The sump of claim 14 further