US3501778A - Self-contained sewerage system - Google Patents

Description

March 1970 M. E. MINNIEAR ET AL 3,501,778

SELF-CONTAINED SEWERAGE SYSTEM Original Filed March 24, 1967 3 t s t 1 FIG-2 IN l/E/V TORS MAX E.MINNIEAR 8: ROBERT C. HELKE A TTORIVEYS March 24, 1970 M. E. MINNIEAR ETAL SELF-CONTAINED SEWERAGE SYSTEM Original Filed March 24. 1967 3 Sheets-Sheet 5 United States Patent F 3,501,778 SELF-CONTAINED SEWERAGE SYSTEM Max E. Minniear and Robert C. Helke, Dayton, Ohio, assignors t Koehler-Dayton, Inc., Dayton, Ohio, a corporation of Ohio Continuation of application Ser. No. 625,647, Mar. 24, 1967. This application Feb. 13, 1969, Ser. No. 805,092 Int. Cl. E03d 1/00; B61d 35/00; A47k 11/02 US. Cl. 410 6 Claims ABSTRACT OF THE DISCLOSURE A self-container sewerage system for passenger vehicles having a unitary thin-walled plastic tank with a rigid bridge reinforcement which supports a substantial portion of the weight imposed on the tank. Reinforcing ribs in the walls of the tank permit the use of uniformly thin walls throughout without loss of structural integrity.

BACKGROUND OF THE INVENTION This application is a continuation of application No. 625,647 filed on Mar. 24, 1967, now abandoned.

Perhaps the most pertinent art to this invention is the United States patents to Dietz et al. No. 3,067,433, issued Dec. 11, 1962 and Herkenhine et al. No. 3,172,131, issued Mar. 9, 1965, both assigned to the assignee of this invention.

These patents relate to a self-contained sewerage system wherein a flush bowl is supported on the top wall of the tank which normally holds a preset volume of flushing liquid. After the unit is used, the flushing cycle is energized causing the pump to force the flushing liquid from the tank upwardly through a manifold surrounding the upper periphery of the bowl from where it flows along the inside of the bowl to flush the contents of the bowl into the tank through a discharge spout. A remotely actuated valve is provided for draining the contents of the tank at a point on the exterior of the vehicle in which the unit is mounted, and similarly a flushing fluid spray device is provided in the unit for rinsing the tank out as a part of the maintenance operation. The tank of this unit is constructed of fiberglass and metal which are secured together by conventional fasteners.

SUMMARY OF THE INVENTION This invention relates to a sewerage system of the aforesaid type wherein a new compact and lightweight tank is provided which is molded of a plastic material as a unit and thus is not susceptible to leakage and whose cost is only a fraction of that of the comparable prior art. Reinforcing ribs are strategically positioned in the thin walled tank to make the tank sufiiciently rigid to support liquid inside together with certain of the lightweight functional components. A rigid bridge structural nesting in the reinforcing ribs or imbedded in the tank material during molding carries the loads externally applied through the flush bowl.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective illustration of the sewerage system in accordance with the invention,

FIG. 2 is a vertical cross-sectional view taken along the line 2 z of FIG. 3;

3,501,778 Patented Mar. 24, 1970 FIG. 7 is a bottom view of the tank showing a portion of the shroud;

FIG. 8 is an enlarged sectional view taken along the line 8-8 of FIG. 2;

FIG. 9 is an end view of the reinforcing shroud showing the tank in broken lines; and

FIG. 10 is a vertical sectional view through the discharge valve.

DESCRIPTION OF THE INVENTION Referring to the drawings wherein a preferred embodiment of the invention is shown, FIGS. 1 and 2 illustrate the sewerage system which includes an elongated completely enclosed tank 10 having the side walls 11 and 12, end walls 13 and 14, and top and bottom walls 17 and 16. A reinforcing shroud or bridge 18 is provided around and outside the tank 10 for aiding in tthe support of the flush bowl 20. The top wall 17 supports the pump-motor unit 21, the timer 22 for the unit 21, the discharge valve assembly 24, the spray tube or manifold 25, and the bowl 20. When installed, the entire tank 10 and all of the components are covered by a housing (not shown) to improve its appearance and to protect the user from possible injury. The system is intended for installation in moving vehicles, such as aircraft, buses, and railway passenger cars.

The tank 10 is made of a plastic material, preferably polyethylene, and thus can be molded as a unit with substantial savings in cost and weight. It has been found that the cost is reduced by as much as -90% of the cost of tanks now in use. The tank will preferably be formed by rotation or blow molding which creates a tank having thicknesses of every surface which are substantially the same. Since the walls are relatively thin, e.g. to inch, reinforcing ribs or indentations are provided and in carefully selected positions to aid in supporting the forces imposed upon the tank. The tank is therefore leakproof since there are no seams in the corners thereof, is corrosion resistant, and the time required to assemble the system is reduced since the tank and cover are formed as a unit.

Each of the end walls 31 and 14 is substantially vertical and has a pair of vertical ribs or indentations 27 therein for adding rigidity thereto. These indentations are carefully designed and placed to add maximum strength to the tank even though the wall thickness is relatively thin. The tank 10 is secured to the supporting surface 28 by the tie-down rod assemblies 30 which include the elongated rods 31 pivotally secured to the brackets 32 mounted on the surface 28. The upper ends of these rods fit into slots 34 (FIGS. 3)in the cross member 35 secured to the top wall 17 of the tank by the conventional fasteners 37. Accordingly, when the knurled nuts 38 are placed on the threaded upper ends 40 of the rods 31 the tank can be clamped to the supporting surface 28. Similarly, the tank can be quickly released by unscrewing the nuts 38 and pivoting the rods 31 away from the adjacent end wall 13 or 14. The tie-down rods fit conveniently in the vertical indentations 27 in the associated end wall, and thus do not add to the longitudinal length of the tank 1 0.

The side walls 11 and 12 of the tank 10 are substantially identical and have a plurality of vertical indentations 41, 42 and 43 therein similar to those in the end walls. The series of indentations 43 are provided in the area of the bowl 20 since all of the weight of a person sitting on the bowl 20 must be carried in this area of the tank 10. The indentation 41 is provided in alignment with the opening 45 in the top wall 17 which receives the pump-motor unit 21, whereas the indentation 42 is in alignment with the opening 47 which receives the discharge valve assembly 24.

The bottom wall 16 of the tank 10 tapers to a discharge opening 50 at the lowest point in the tank, as seen in FIG. 2, to enable all of the contents to drain under the force of gravity from the tank. A plurality of feet 52 are provided on the bottom wall 16 for engaging the surface 28 to compensate for the tapered bottom wall 16 of the tank to hold the tank 10 in a horizontal position free from any rocking movement.

As indicated above, the top wall 17 of the tank supports all of the components of the system and it also includes a series of indentations for adding rigidity to this wall. The pump-motor unit 21 is thus secured in the opening 45 by inserting appropriate fasteners 54 through the flange 55 on the unit and through the periphery of the circular opening 45. A circular indentation 58 surrounds this opening 45 and communicates through the short indentations 61 and 62 with the vertical indentations 27 and 41 in the end and side walls thereby adding rigidity to this area of the top wall 17. The timer 22 for the motor is secured to the cross member 35 by the connectors 37, and t the unit 21 by the electrical connector 64. The timer 22 and pumpmotor unit 21 are described in the aforesaid Dietz et a1. patent.

The discharge valve assembly 24 is secured to the top wall 17 in much the same manner as the pump-motor unit 21 with the connectors 65 (FIG. extending through flange 66 on the assembly 24 and the periphery of the circular opening 47. A circular indentation 68 is also provided in the top wall surrounding this opening and in communication through the short indentations 70 with the vertical indentations 42 in the side walls 11 and 12.

The valve assembly 24 includes a downwardly extending tube 72 secured to the top plate 73 (FIG. 10) by the connectors 74. The lower tube 75 has the valve 76 mounted on the lower end thereof. The rubber ring 77 on the valve 76 engages the valve seat 78 formed in the bottom wall 16 of the tank in communication with the discharge opening 50. The lower tube 75 is adapted to fit snugly inside the upper tube 72 to telescope therein against the bias of the coil spring 80 which is interposed between the upper end 81 of the upper tube 72 and the shoulder 82 formed in the lower tube 75. Accordingly, the lower tube 72 and the valve 76 are constantly urged down wardly against the valve seat 78.

A vertical bore 84 is provided in the upstanding projection 85 in the lower end of the lower tube 75 to house the coil spring 86 between the upper shoulder 87 and the retainer 88 whose downward movement is blocked by the pin 89. This retainer 88 is connected to the actuator cable 90 which extends upwardly through the tubes 72 and 75, through an opening 92 in the mounting flange 73, around a pair of pulleys 93 and 94, and downwardly through the indentation 42. The end of this cable is connected to a remote actuator for opening the valve 76 to empty the tank from a point exterior of the vehicle. The coil spring 86 maintains a preset amount of tension on the cable 90 after it is connected to the remote actuating mechanism so that there is little or no looseness in the cable.

The reinforcing bridge 18 is an important part of the invention and extends around the tank 10 in the area of the indentations 43 shown in FIG. 4. The bridge includes a top plate 100 which covers the elongated opening 101 in the top wall 17 of the tank and is secured to the upstanding shoulder 102 which defines the elongated opening 101 by a plurality of conventional fasteners 103. The top plate 100 has the circular opening 104 therein for receiving a portion of the bowl 20, as will be seen. As

seen in FIGS. 2, 6 and 8 some of the fasteners 1'03 pass' posite edges of the top plate to add rigidity and strength thereto.

The top plate is supported by the side members 11 which extend vertically downwardly adjacent the side walls 11 and 12 in interlocking engagement with the series of indentations 43 for cooperation therewith. The side members have the horizontal flanges 111 which are disposed adjacent the ends of the elongated opening 101 and support the top plate 1'00 which is connected thereto by the conventional connectors 113. The side members 110 have indentations 115 (FIG. 6) formed therein adjacent the side edges 116 thereof to engage the complementary projection 43a and indentation 43b in the side walls 11 and 12 while the central portion 118 thereof spans the two centermost indentations 430. The side members 110 extend downwardly and contact the supporting surface 28 so that all or most of the weight on the bowl 20 and the forces imposed thereon are transferred directly to the supporting surface through the top plate 100 and side members 110. A cross member 120 extends between the lower end of the central portions 118 of the side members 110 beneath the tank 10 to hold the shroud 18 in place and to maintain the side members 110 in close interlocking engagement with the indentations 43.

The reinforcing bridge is thus an important feature of the invention and permits the use of a relatively thin plastic tank by reason of its cooperation with the indentations 43 and the structure of the tank 10 to support the weight imposed upon the flush bowl 20. It is also possible to mold the bridge partially or entirely within the plastic tank. The top plate 100 and side members 110 of the shroud may be made of any suitable rigid material capable of being formed into the shape illustrated and supporting the weight present. For example, a molded fiber glass material has been found to be satisfactory, although it would be also possible to use various types of metals and rigid plastics. The elongated opening 101 allows the flush bowl 20 to be mounted on either side of the tank 10 thus permitting flexibility in installation of the system. It is merely necessary to remove, reverse, and replace the top plate 100 and secure the bowl to the opposite end of the elongated opening in substantially the same manner as described above.

In operation, the system is installed in an aircraft or other vehicle with the discharge outlet 50 in the bottom of the tank in communication with a conduit leading to a discharge orifice (not shown) in the exterior of the vehicle. Similarly, the spray manifold 25 mounted on the interior of the tank 10 is connected to a supply conduit through either of the connectors 126 (FIG. 2). The tank is filled to a preset depth with a flushing liquid and thus is ready for use. When it is desired to flush contents from the bowl into the tank, the operator actuates a suitable switch which energizes the pump-motor unit 21 for a preset time as determined by the timer 22. The unit 21 draws the liquid through the filter 127 upwardly through the conduit 128 from where it flows from the manifold 129 around the upper periphery of the bowl 20, along the side surfaces 130 of the bowl, and through the discharge spout 132 into the tank 10 to wash the contents of the bowl 20 into the tank 10.

When it is desired to empty the unit, a service vehicle or its equivalent is connected to the discharge conduit 125 and to a supply line leading to the connector 126. The valve assembly 24 is actuated to open the valve 76 and allow the contents of the tank 10 to flow under the force of gravity through the discharge opening 50 and into the discharge conduit 125. At the same time, the fresh liquid is sprayed through the manifold 25 to wash and flush all of the materials from the tank. Once the rinsing operat on is completed, the valve 76 is closed and the tank 10 filled again to the preset level with flushing liquid, and thus is ready for use once again.

The novel tank structure permits a lightweight tank which will support all of the components of the system,

and cooperates with the reinforcing bridge to support the weight imposed on the bowl. The tank is formed as a single unit, and because of its specific design which permits thin walls and the use of plastic, it is lighter in weight and much less costly than the conventional stainless steel and fiber glass units used heretofore.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention.

What is claimed is:

1. A self-contained sewerage system comprising, a closed tank, said tank having top, bottom, end walls and side walls and capable of receiving and holding waste material and a flushing liquid, means defining an opening in said top wall, a waste receiving flush bowl mounted on said top wall in alignment with said opening and having a discharge spout to the interior of said tank to direct the waste material from said bowl through said discharge spout and into said closed tank, and a reinforcing bridge around and outside said tank or molded partially or entirely within said tank carrying the weight of said bowl and at least a substantial portion of the load applied to said bowl, said reinforcing bridge having top plate means secured to said bowl, side members secured at the opposite ends of said top plate means and downwardly adjacent said side walls of said tank, and said side members having lower ends which engage a support surface so that the weight imposed on said bowl is transferred to such support surface and is not carried entirely by said tank to provide additional support for said top plate means independent'of said top and side walls of said tank.

2. A self-contained sewerage system as defined in claim 1, wherein an upstanding shoulder portion is provided in said top wall for supporting said bowl above said top wall, and means for interconnecting said bowl, said bridge and raised shoulder.

3. A self-contained sewerage system as defined in claim 1, wherein a plurality of vertically extending indentations are provided in said side walls in front of and behind said bowl to add rigidity and additional support for the weight imposed upon said bowl.

4. A self-contained sewerage system as defined in claim 3 wherein said reinforcing indentations include a plurality of vertical indentations in each of said end and side walls for adding rigidity to said tank.

5. A self-contained sewerage system as defined in claim 1, wherein a plurality of openings are provided in said top wall for receiving and supporting the components of the sewerage system, and a generally circular indentation surrounding each of said openings for adding rigidity thereto supporting said components entirely on said top wall.

6. A self-contained sewerage system as defined in claim 1 wherein said opening in said top wall is elongated, said top plate means has a circular opening therein above which said flush bowl is supported, said top plate being reversible end for end and capable of positioning said bowl adj acent the opposite sides of said tank.

References Cited UNITED STATES PATENTS 2,027,083 1/1936 Baer 2'20-47 2,298,293 10/ 1942 Hothersall 220-47 2,365,080 12/1944 Humphreys 244-135 2,381,400 8/1945 Stavely et al. 244-135 2,508,906 5/1950 Cunningham et al. 244-135 2,838,261 6/1958 Amos et a1. 244-135 2,899,096 8/ 1959 Henchert et al. 220-47 3,057,588 10/1962 Kolbe 244-135 3,067,433 12/1962 Dietz et al. 4-115 3,147,941 9/1964 Hawthorne 244-135 3,172,131 3/1965 Herkenhine et al. 4-115 3,289,214 12/ 1966 Corliss 4-115 FOREIGN PATENTS 157,812 7/ 1954 Australia.

530,525 12/ 1940 Great Britain.

533,510 12/ 192.1 France. 1,300,510 6/1962 France.

LAVERNE D. GEIGER, Primary Examiner D. MASSENBERG, Assistant Examiner US. Cl. X.R. 4-8,

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