US 3897599 A
A long, thin, flexible tube of reduced diameter is connected to a fitting mounted in a side wall of a sewage holding tank. The fitting is coupled to a quick disconnect valve mounted at a suitable location in a passenger vehicle. The tube has sufficient length and flexibility so that it will extend substantially across a smaller dimension of the tank and will be whipped through angles of more than 270 DEG when a cleaning fluid or water is discharged through the hose. The tube will pound upon the tank bottom and upon solid or semi-solid deposits on the tank bottom as it projects a cleansing stream of water, and yet is arranged so that its whipping end will not enter the tank drain.
Description (OCR text may contain errors)
United States Patent [1 1 Artzer 1 1 HOLDING TANK WITH QUICK DISCONNECT VALVE  inventor: Richard F. Artzer. 181 12 Larkstone. Santa Ana, Calif. 92704  Filed: July 16.1973
 US. Cl. H 4/10; 4/172; 4/17115;
134/167 R;134/168 R  Int. Cl E04h 3/16; E04h 3/18  Field of Search 4/1. 10 172.15, 17216,
1 1 Aug. 5, 1975 Primary I;.\uminerHenry K. Artis Assistant E.\'uminer,1ames E. Bryant, 11] Attorney, Agent. or FirmGausewitz, Carr & Rothenberg (57] ABSTRACT A long, thin, flexible tube of reduced diameter is connected to a fitting mounted in a side wall of a sewage holding tank. The fitting is coupled to a quick disconnect valve mounted at a suitable location in a passenger vehicle, The tube has sufficient length and flexibility so that it will extend substantially across a smaller dimension of the tank and will be whipped through angles of more than 270 when a cleaning fluid or water is discharged through the hose. The tube will pound upon the tank bottom and upon solid or semi-solid deposits on the tank bottom as it projects a cleansing stream of water, and yet is arranged so that its whipping end will not enter the tank drain 4 Claims, 3 Drawing Figures PATENTEDMJE 5% 60 Ek/G HOLDING TANK WITH QUICK DISCONNECT VALVE BACKGROUND OF THE INVENTION The present invention relates to holding tanks for passenger vehicle sewage systems and more particulary concerns methods and apparatus for breaking up solid concentrations of deposited sludge and concomintantly providing a cleaning and flushing action, all under re mote control.
For reasons of convenience and ecology, and more recently as required by laws and regulations, portable toilets of passenger vehicles, such as boats, campers, trailers and the like, carry holding tanks. A holding tank conventionally is a completely enclosed thin walled container fixedly mounted to the vehicle, having a two to four inch input conduit connected to receive sewage from a toilet bowl and having a valve controlled drain for periodic discharge of sewage from the tank.
The holding tank is periodically emptied particularly when facilities are available for collection or connection of the tank drain to another sewage system. Commonly, during the cleaning and during the draining of the holding tank, a hose, such as an ordinary garden hose, is inserted into the tank via the connecting toilet bowl and flushing water is caused to flow into the tank while the tank drain is opened. This is a difficult and unpleasant task in most situations and is not effective in properly cleaning the entire inside of the tank. Further, sewage collected in the tank may include soilds and semi-solid material and paper. Such materials tend to solidify or cake, forming rather hard bodies and sur face layers that resist penetration of water.
US Pat. No. 3,501,778 to Minniear et al. describes a self-contained sewage system for a passenger vehicle in which a spray tube or manifold is mounted within an upper portion of the holding tank whereby cleansing water may be directly fed to the interior of the tank without the need to insert a hose through the bowl. Such an arrangement eliminates certain disadvantages of a bottom-mounted fixed spray device that has also been employed for holding tank cleaning. The mounting of the spray tube at or near the top of the tank will tend to minimize the problem ofclogging and blocking of the bottom mounted spray by collections of solid and solidifying sludge. Nevertheless, the spray provided by the spray tube of the apparatus of Minniear et al. is not sufficient to adequately agitate the tank contents nor to render and break up solidified sludge and masses of paper.
Accordingly, it is an object of the present invention to provide a remotely operable method and apparatus for achieving more effective cleaning of holding tanks.
SUMMARY OF THE INVENTION In carrying out principles of the present invention in accordance with a preferred embodiment thereof, a long. thin flexible tube is mounted by means of a sealing fitting through a side wall of the holding tank so as to allow the tube end to extend a considerable distance into the tank. The tube is adapted to be detachably connected to a valve controlled supply of pressurized cleaning liquid which may be selectively projected from the end of the tube, thereby to cause the tube to whip about throughout the tank and through the con tents thereof to break up the deposited sludge by a combination of pounding of the tube itself and impingment of the projected stream.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a holding tank illustrating relative position ofa typical drain and an agitating and flushing hose of the present invention;
FIG. 2 is a cross section through the tank of FIG. I; and
FIG. 3 is an enlarged sectional view through the wall hose fitting.
DETAILED DESCRIPTION A conventional holding tank, as illustrated in FIG. I, compriese a relatively flat elongated sealed container formed of sheet metal, rigid plastic or the like, and having a top wall 10, bottom wall 12, and side walls I4, l6, l8 and 20. The bottom wall 12 slopes downwardly from both sides 14 and 16 to form a bottom trough 22 which itself slopes from one side wall 20 downwardly toward the opposite side wall 18. A drain fitting 24 is connected to the lowermost point of the trough 22 and is commonly connected to a valve controlled conduit (not shown).
Extending through the side wall 16 of the tank in sealing relation thereto is a fitting 26 having a portion 28 (FIG. 3) projecting internally of the tank and a portion 30 extending externally of the tank. A thin-walled, flexible hose or tube 32 is outwardly expanded at an inner end 34 thereof to be forced over serrations 36 formed on the inwardly projecting portion of the fitting, thereby effecting a liquid tight seal. The outer or free end 40 of the tube 32 is formed merely by cutting the illustrated tube length from a greater length. No nozzle is needed or employed and no particular shaping of the tube end 40 is needed or employed.
The externally extending portion 30 of the fitting 26 includes an externally threaded body section 42 (FIG. 3) to which is connected a hose 44 which has the other end thereof connected to a valve controlled fitting 46. Valve controlled fitting 46 is preferably mounted to and beneath the vehicle that carries the holding tank I0 and may be of any conventional and common configuration that enables the fitting to be quickly connected and disconnected to a source of pressurized liquid, such as a common water supplyv Fitting 46 contains suitable valving (not shown) that enables the tank 10 and hose 44 to be sealed when the outside pressurized supply is disconnected.
Holding tank 10 may be mounted or carried in any one of a number of positions or locations. Commonly, the holding tank is mounted as nearly as possible directly below a toilet bowl that is carried by the vessel, camper, trailer, motor home, sailing or flying vessel and is connected thereto in a conventional manner by means of an inlet fitting 48 formed in the tank to wall and by additional conduits (not shown).
The fitting 26 includes the internally projecting section 28 and the end section 42 integrally formed with an intermediate section 50. Intermediate section 50 includes a threaded portion 52 and an outwardly tapered exterior surface 54 that extends from a larger diameter portion inside the tank to a smaller diameter portion outside the tank. At the inner portion of the intermediate section (at the larger diameter section of the tapered surface) there is integrally formed a radially projecting peripheral flange 56. The wall I6 through which the fitting is to be mounted is formed with a hole 58 having an internal diameter equal to or slightly greater than the external diameter of the flange 56 of the fitting 26 so that the fitting may be inserted through the hole to position the flange $6 inside the tank. A first flexible washer 60 has an internal diameter less than the diameter of the flange 56 and has an external diameter greater than the diameter of the hole 58. This washer is formed with sufficient flexibility so that it may be folded somewhat after being inserted over the external portion of the fitting and then pushed through the hole 58 in wall 14 between the tapered surface 54 of the fitting and the wall 16 to the interior of the tank where it will resiliently expand to attain the configuration and position shown in FIG. 3.
A second resilient washer 62 is then inserted over the externally extending portion of the fitting into the hole 58 in side wall 16. Second washer 62 has an external diameter substantially equal to the internal diameter of the hole 58 and has an internal diameter which, in normal unstressed position of the second washer 62, is slightly greater than the outer diameter of the intermediate portion of the tapered exterior surface of the fitting. Therefore, this resilient second washer 62 will be caused to expand outwardly and to be firmly compressed radially between the inner surface of the hole 58 and the exterior tapered surface of the fitting when the fitting is drawn to the right (relative to wall 16 as viewed in FIG. 3) by means of a holding nut 64 that is threadedly engaged with the threads 52 on the externally threaded body section of the fitting. A third resil ient washer 68 and a rigid metallic washer 70 are also interposed between the external surface of the tank wall and the holding nut 64.
The fitting is made with a necked down bore having a relatively large internal diameter 72 at the exterior portion of the fitting and a relatively small internal diameter 74 at the interior section of the fitting. The exterior section of the fitting has a relatively large exte rior diameter capable of accepting a conventional hose 44 of 7/16 to inch inside diameter or more. For purposes to be described below the internal section 28 of the fitting has a diameter that enables it to be connected to tube 34 of a considerably smaller diameter, such as V4 inch inside diameter, for example. The fitting is preferably made of a rigid, noncorrosive plastic or suitably protected metal.
Tube 32 is preferably formed of a thin wall, resilient plastic tubing such as that known as Tygon, for example. Brass or aluminum or stainless steel may also be used for the fitting. The length and flexibility of the tube 32 and also the location of the fitting with respect to the valve controlled dump fitting 22 are significant aspects of the practice of the present invention.
The tube 32 has a length substantially equal to or just less than the distance between the two more closely spaced walls of the tank. Thus, where the tank is of a generally rectangular configuration in plan view, hav ing relatively long, mutually closely spaced walls l4, l6 and relatively short further spaced end walls [8, 20, the tube will have a length just less than the distance between the longer, more closely spaced walls 14, 16. For a tank about ten inches deep, having a length of about five feet and a width of about 30 inches. a tube having a flexible length of approximately 24 inches, a wall thickness of Vs inch or less and an inside diamcter of not more than /16 inch may be employed. In any event, to achieve optimum agitating action. the tube should have a length of more than 12 inches. and at least 18 inches. a diameter of less than a inch. preferahly not more than 5/16 inch and the thin Vs inch wall thickness. The tube 32 has sufficient body stiffness to prevent it from being flattened or closed by the weight of materials deposited at the tank bottom. but, nevertheless, has sufficient flexibility so that it may readily flail throughout the tank and through the contents thereof in an irregular pattern in which the end 40 of the hose will move through an arc of more than and through angles as great as 270 or more. thereby allowing the liquid projected from the end 40 to be directed at the entire interior surface of the tank.
Normally. the tube 32 will extend at least partly across the tank resting partly upon the bottom or supported at least in part by the tank contents. When the tank is full or nearly full, the valve controlled dump fitting 24 is connected to a suitable external sewage systern, valve control fitting 46 is connected to a water supply or other supply of pressurized liquid cleaning solution. This liquid cleaning solution is thereupon al lowed to flow under a pressure of from 15 to 40 lbs. per square inch through the relatively large internal diameter hose 44 to the fitting 26 where the liquid stream is constricted by the narrow fitting portion 74, and thence into the tank, as it continues to be constricted by the relatively small internal diameter tube 32. Accordingly. the liquid flows with increased velocity through the entire length of the tube 32 and is not merely constricted by a nozzle at the tube end. The relatively high velocity liquid is projected from the end of the tube to react with the highly flexible tube and cause the latter to flail about within the tank and through the tank contents. As previously described, the flailing tube has sufficient length and sufficient flexibility so as to provide a dual cleaning action. A first aspect of the cleaning action is due to the impingment of the relatively high velocity liquid stream from the tube end upon the tank contents and upon the tank walls. A second aspect of this action is the beating and pounding action of the tube upon the solid and scmisolid material at the bottom of the tank and upon the tank bottom itself. The latter arrangement is particularly enhanced by the chosen relatively long flexible length of tubing 32. Of course. during the cleansing and flushing action, the valve in the dump fitting 24 is opened to allow the liquid tank contents and the rendered solids of the tank contents to be discharged.
An additional feature of significance is the location of the hole 58 in the tank wall which is chosen in view of the preferred length of tube so that the end 40 of the tube 32 is less than the distance from the hole 58 to the dump fitting 24. This will prevent the end of the long tube from entering the dump fitting and interfering with operation of either the draining function or of the drain valve itself. Thus. as illustrated in FIGS. 1 and 2, where the dump fitting 24 is located in sidewall 18 at one end of the tank. the hole 58 for the fitting 26 will be positioned either in the opposide end wall 20 or in one or the other of sidewalls l4, 16 at a point thereof sufficiently removed from the dump fitting 24 so as to prevent the tube end from entering the dump fitting. Subject only to this last-mentioned limitation concerning interference with the dump fitting by the end of the tube, the tube 32 and the fitting 26 are preferably positioned in one of the side walls at a near central location in order to provide optimum agitation and disturbance both by the projected stream of liquid and by the flailing of the tube itself throughout substantially the entire volume of the tank. If deemed necessary or advisable,
a check valve (not shown) may be mounted within the 5 fitting 26.
It will be seen that there have been described meth- The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.
What is claimed is: I. In combination with a holding tank having a top wall, a bottom wall and side walls, having an inlet for receiving sewage, and having a valve controlled dump connection for draining sewage therefrom, a sewage agitating and tank cleaning device comprising a fitting extending through one of said side walls of said tank, said fitting having a first section external to the tank adapted to be connected to a source of water pressure, and having a second section extending a short distance into said tank, and
a long, thin, flexible tube mounted upon said internal fitting section and extending entirely within said tank, said tube having a length and a flexibility sufficient to permit the free end of the tube to swing through an arc of approximately 270 when liquid under pressure is caused to flow through said fitting and through the tube, and whereby the tube will thrash about within said tank and project said liquid from the end thereof toward the walls of the tank, thereby to agitate the tank contents by means of both the force of liquid projected from the tube and by the pounding ofthe tube upon the tank, said fitting comprising an internally projecting portion receiving said tube thereon, an intermediate section having a radially outwardly projecting peripheral flange of a diameter substantially equal to the diameter of said hole said flange being positioned inside of said tank, said intermediate section having a tapered exterior surface extending from a larger diameter inside said tank to a smaller diameter portion outside of said tank, an externally threaded body section on the fitting adjacent said tank wall, an exterior end section on the fitting, and means interposed between said tank wall and said intermediate fitting section for sealing the fitting to the tank wall.
2. The apparatus of claim I wherein said means for sealing the fitting to the tank wall comprises a first flexible washer having a diameter larger than the diameter ofthe hole in the tank wall and interposed between said peripheral flange and the inside of said tank, a second washer having an outside diameter substantially equal to the internal diameter of the hole in the tank wall and having an internal diameter substantially equal to the diameter of an intermediate portion of said tapered exterior surface of the fitting, a nut threaded upon said intermediate fitting section, and an exterior washer pressed between the tank wall and said nut.
3. The apparatus of claim 2 wherein said tube within the tank has a length less than the distance between the hole in said tank wall and said valve controlled dump connection.
4. The apparatus of claim 2 wherein said hole in the tank wall is so positioned that the length of the tubing within the tank is less than the distance from the hole in the tank wall to the valve controlled dump connection, and greater than the distance from the hole in the tank wall to the bottom of the tank.