Patent Publication Number: US-2022221096-A1

Title: Black tank sewer flush adapter

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to U.S. patent application Ser. No. 15/984,041, entitled “Extender for Vehicle Sewer Connection,” filed May 18, 2018 and issued Dec. 15, 2020 as U.S. Pat. No. 10,865,556. 
    
    
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. Copyright ○ 2021 Jeffery Wright. 
     FIELD OF THE INVENTION 
     The present disclosure is in the technical fields of pipe or conduit fittings, adapters or couplings, especially those for use with sanitary sewer connections. Another technical field is sewer hookup accessories for recreational vehicles, motorhomes, fifth wheels, trailers, and other like vehicles. 
     BACKGROUND OF THE INVENTION 
     The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. 
     Many recreational vehicles, motorhomes, fifth wheels, trailers, and other like vehicles are equipped with lavatories or water closets and “black” tanks that store sewage until the waste can be drained to an external sewer line, tank, or blackwater recovery facility. The black tank is typically connected to piping that terminates at a waste valve near the exterior of the vehicle, often on the underside or chassis of the vehicle. 
     To drain waste from the black tank, it is typically necessary to connect the waste valve of the vehicle to an external sewer drain. The typical approach is to connect one end of a flexible sewer hose to the vehicle&#39;s waste valve and the other end of the sewer hose to the sewer drain. 
     Despite regular discharge of waste from the black tank, sewage can accumulate on the interior walls of the tank over time. Cleaning the interior of the black tank conventionally involves partially filing the black tank with water from multiple flushes of an attached toilet bowel where one or more of the flushes includes a chemical treatment added to the bowl water before flushing. The treated water is then allowed to stand in the black tank for some time to react with the sewage before it is drained from the black tank via the waste valve. 
     Some vehicles are equipped with a black tank flush system that includes an exterior-facing water inlet valve that allows for connection to a water source via a water hose connection. 
     There are also black tank sewer flush adapters that can attach to the vehicle&#39;s waste valve and a sewer hose. The adapters have a fitting protruding from a portion of the adapter to which a water hose can be attached to fill the black tank with water. The standing water and sewage can then be drained from the black tank to a sewer drain via the attached adapter and sewer hose. 
     Efforts are continually being made to increase the efficiency of cleaning the black tank interior. 
     SUMMARY OF THE INVENTION 
     In a first aspect, the present invention provides a vehicle black tank sewer flush adapter comprising a tubular body having a proximal end opening and a distal end opening. A boss connector is connected to or integrally formed to the tubular body. The boss connector comprises a distal end opening through which a water hose can pass longitudinally and extend from both the distal end opening of the boss connector and the proximal end opening of the tubular body and into the black tank. The flush adapter further comprises a flexible sealing washer and a fastener each comprising an opening through which the water hose can pass longitudinally. The fastener is for forming an attachment with the distal end of the boss connector while the water hose passes longitudinally through at least all the opening of the fastener, the opening of the flexible sealing washer, and the distal end opening of the boss connector. 
     In a conventional vehicle black water sewer flush adapter, an end of the water hose is attached to the distal end of a fitting protruding from the conventional adapter. As a result, the end of the water hose from which the stream of water is emitted cannot be extended into the interior of the black tank, resulting in decreased pressure washing efficiency. By allowing the water stream emitting end of the water hose to pass through the boss connector and the proximal end of the flush adapter and into the black tank, the water stream can be applied directly to the interior surfaces of the black tank and a net increase in dislodging adhered sewage from the interior surfaces of the black tank is observed. 
     The fastener may comprise internal threads for forming a secure threaded attachment with the distal end of the boss connector that is externally threaded. The threaded attachment may be conveniently formed while the water hose passes longitudinally through all the opening of the fastener, the opening of the flexible sealing washer, and the distal end opening of the boss connector to secure the flexible sealing washer at the distal end opening of the boss connector in a leak resistant manner. 
     The flexible sealing washer may be flexible enough to allow the water hose to traverse the washer opening longitudinally when a pull or push force is applied to the water hose such as by a human using a hand gripping the water hose near the boss connector. This allows the nozzle of the water hose to be moved to different positions inside the black tank and thereby increasing the area inside the black tank to which a pressurized water stream is applied. At the same time, the flexible sealing washer may form a leak resistant seal around where the water hose traverses the washer opening to reduce or eliminate leakage out through the washer and fastener and increase or maximize the sewage from the black tank that drains out through the distal end of the flusher adapter. 
     The tubular body of the flusher adapter can be straight or have an elbow angle to accommodate various vehicle waste valve angles and positions on the vehicle and different sewer drain angles and locations. 
     The opening of the fastener, the opening of the flexible sealing washer, and the opening of the distal end of the boss connector may each have a respective diameter sufficient to accommodate water hoses of one or more different diameters such as, for example, one-quarter of an inch, three-eighths of an inch, one-half of an inch, five-eighths of an inch, or three-quarters of an inch. The diameter of the flexible sealing washer may be smaller than both the diameter of the fastener and the diameter of the distal end of the boss connector to form a leak resistant seal around the water hose while still allowing the water hose to longitudinally traverse the flexible sealing washer opening when a push or pull force is applied to the water hose. 
     The tubular body of the flush adapter may include a transparent portion made of clear acrylic or other suitable transparent material that allows for visual observations of sewage draining from the black tank through the tubular body. This allows the operator to observe when the black tank is sufficiently flushed of sewage. 
     As well as being externally threaded, the distal end of the boss connector may be internally threaded to allow formation of a threaded attachment with a water hose connector. In this configuration, a garden hose or other type of water hose can be attached to the water hose connector to flush components of residual sewage such as the flush adapter itself and other sewage drainage components situated downstream of the flush adapter such as the sewer hose or the “Sewer Extender” described in U.S. Pat. No. 10,865,556 entitled “Extender for Vehicle Sewer Connection,” filed May 18, 2018 and issued Dec. 15, 2020, the entire contents of which is hereby incorporated by reference. 
     The proximal end of the flush adapter can be glued or otherwise connected to an adapter with sewer hose adapter fittings for connecting to a bayonet flange with lug fittings of the vehicle&#39;s waste valve. The distal end of the flush adapter can be glued or otherwise connected to a bayonet flange adapter with lug fittings. The bayonet flange adapter can then connect to a sewer hose or the Sewer Extender with sewer hose adapter fittings. Alternatively, the distal end of the flush adapter can be connected to the telescoping body of the Sewer Extender and replacing the hose elbow coupling of the Sewer Extender. 
     In a second aspect, the present invention provides a black tank sewer flush kit comprising the vehicle black tank sewer flush adapter as described in any of the preceding paragraphs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the present invention may be more readily understood, embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which like reference numerals refer to like elements throughout the figures, and in which: 
         FIG. 1  is an exploded front perspective view of a black tank sewer flush kit in accordance with the present invention. 
         FIG. 2  is a front perspective view of the assembled black tank sewer flush kit and depicting a use of the kit in accordance with the present invention. 
         FIG. 3  is a rear perspective view of the assembled black tank sewer flush kit in accordance with the present invention. 
         FIG. 4  is a side view of the assembled black tank sewer flush kit in accordance with the present invention. 
         FIG. 5  is a top view of the assembled black tank sewer flush kit in accordance with the present invention. 
         FIG. 6  is a bottom view of the assembled black tank sewer flush kit in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The vehicle black tank sewer flush kit  1  of  FIG. 1  comprises a proximal adapter  2 , a flush adapter  3 , and a distal adapter  4 . Here, proximal adapter  2  is “proximal” and distal adapter  4  is “distal” in the sense that proximal adapter  2  is physically closer to the vehicle&#39;s waste valve than distal adapter  4  when kit  1  is assembled and installed for use. Adapters  2 ,  3 , and  4  may be formed of ABS polymer, PVC polymer, or other suitable plumbing material (e.g., aluminum). 
     In  FIG. 1 , adapters  2 ,  3 , and  4  of kit  1  are shown in an exploded view for the purposes of providing a clear example. However, in a practical implementation, adapters  2 ,  3 , and  4  may be glued together or otherwise connected as a single unit. While glue has been mentioned, alternatively screws or threaded attachments may be substituted for adhesive. In any case, the distal end of proximal adapter  2  may be connected to the proximal end of flush adapter  3  and the distal end of flush adapter  3  may be connected to the proximal end of distal adapter  4  in a watertight manner that prevents sewage from leaking between the connection points of the adapters  2 ,  3 , and  4  as the sewage drains through the hollow interiors of adapters  2 ,  3 , and  4 . 
     Each of adapters  2 ,  3 , and  4  are generally hollow tubes, cylinders, or pipe segments having open interior cavities through which water and sewage may pass when kit  1  is assembled and installed for use. For example, ABS, PVC, or aluminum pipe having a nominal three-inch diameter and compatible couplers (e.g., bell end) may be used. 
     In  FIG. 1 , flush adapter  3  is an elbow adapter with a 45-degree angle. However, flush adapter  3  could instead be a straight adapter or an elbow adapter having an angle other than 45 degrees (e.g., 90 degrees). Generally, the angle may be selected based on the conditions in which flusher adapter  3  will be used. For example, the angle of flush adapter  3  can be between zero and ninety degrees. The conditions that may affect angle choice may include the angle and location of the vehicle&#39;s waste valve, the angle and location of the sewer drain connection relative to the angle and location of the vehicle&#39;s waste valve, and whether the Sewer Extender is used. In one scenario where the Sewer Extender is used, flush adapter  3  is a straight coupling and the Sewer Extender encompasses an elbow coupling having an angle between zero and ninety degrees. 
     Proximal adapter  2  includes standard sewer hose adapter fittings  17  for connecting to a bayonet flange with standard lug fitting of the vehicle&#39;s waste valve. Distal adapter  4  encompasses a bayonet flange with standard lug fittings  18  for connecting to a sewer hose with standard sewer hose adapter fittings or, alternatively, for connecting to the Sewer Extender with standard sewer hose adapter fittings. In some embodiments, sewer hose adapter fittings  17  can be manually rotated three-hundred and sixty (360) degrees around a longitudinal axis of proximal adapter  2  for convenience in connecting kit  1  to the bayonet flange of the vehicle&#39;s waste value and for convenience in positioning kit  1  when assembled and installed for use. 
     In some embodiments, kit  1  includes only proximal adapter  2  and flush adapter  3  and does not include distal adapter  4 . In these embodiments, the distal end of flush adapter  3  may be connected to the telescoping body of the Sewer Extender. Such connection may be made by adhesive, by screws, by threaded attachment, or by other suitable watertight attachment mechanism. 
     Proximal adapter  2  and distal adapter  4  shown in  FIG. 1  are merely examples of possible proximal and distal adapters of kit  1 . Other proximal and distal adapters with different fittings and of different dimensions may be used according to the requirements of the particular implementation at hand including the requirements dictated by the vehicle&#39;s waste valve connection, the sewer hose connection, or a connection with the Sewer Extender. 
     Flush adapter  3  has a tubular body  7  with a proximal end opening  5  and a distal end opening  6 . A boss connector  8  may be connected to or integrally formed to the tubular body  7 . For example, tubular body  7  with boss connector  8  may be manufactured as a single piece using an injection molding or three-dimensional printing process. However, boss connector  8  may also be a separate piece that is connected to the tubular body  7  via a watertight connection. For example, the watertight connection may be a watertight threaded connection whereby the proximal end of the boss connector  8  is threadedly attached to the tubular body  7  at a threaded connection point on the tubular body  7 . Where a watertight connection is used to connect boss connector  8  to tubular body  7 , the water connection may accommodate connecting tubular body  7  to different boss connectors with different diameters to accommodate different water hoses of different nominal diameters. 
     Boss connector  8  has a distal end opening  9 . Distal end opening  9  is “distal” in the sense that it is farther away from the tubular body  7  than the proximal end opening (not shown) of boss connector  8  that opens into the hollow interior of the tubular body  7 . Boss connector  8  is a generally hollow tube, cylinder, or pipe segment having an open interior cavity through which a water hose may pass when inserted, for example, into distal end opening  9  of boss connector  8  and out through the proximal end opening of boss connector  8  and proximal end opening  5  of tubular body  7 . Boss connector  8  may be formed of the same or a different material as tubular body  7 . For example, boss connector  8  may be formed of ABS, PVC, aluminum, or other suitable plumbing material. 
     The diameter of distal end opening  9  of boss connector  8  as well as the interior diameter of the boss connector  8  should be of sufficient size to allow a standard water hose to pass through the opening  9  and connector  8  when the standard water hose is not attached to a nozzle. If the water hose nozzle is too large to fit through opening  9  and connector  8 , the nozzle may be attached to the water hose after the water hose is passed through opening  9  and connector  8 . 
     In an implementation, the diameter of distal end opening  9  of boss connector  8  is one-half inch or otherwise sufficient to accommodate up to a nominal one-quarter of an inch diameter pressure washing hose for use with a consumer grade electric or gas-powered pressure washer. However, the diameter may be larger to accommodate larger nominal diameter water hoses. The diameter of distal end open  9  may be selected to easily accommodate one or more of the following nominal water hose diameters: three-eighths of an inch, one-half of an inch, five-eighths of an inch, or three-quarters of an inch. 
     As shown in  FIG. 2 , which shows kit  1  of  FIG. 1  in an assembled configuration, when flusher adapter  3  is in use, a water hose  19  may pass through all of the opening  13  of fastener  12 , the opening  11  of flexible sealing washer  10 , opening  9  of boss connector  8 , proximal end opening  5  of tubular body  7 , passing the vehicle&#39;s waste valve through the piping connecting the waste valve to the black tank, and into the interior cavity of the black tank. When water hose  19  is in this position, water pressure can be applied directly from nozzle  20  of water hose  19  to the interior walls of the black tank to achieve a direct washing effect and help loosen and dislodge any sewer sludge or other sewage that has adhered to the interior tank walls. 
     Further, an operator can grip water hose with a hand  21  near the distal end of boss connector  8  and apply a push  22  or pull  23  force to water hose  19  to move nozzle  20  to different locations within the black tank. This allows for greater area of the tank interior to which direct water pressure is applied thereby increasing the potential for dislodging or loosening adhered sewage from the tank walls. 
     When kit  1  is assembled and installed on a vehicle&#39;s waste valve, push force  22  by hand  21  can be applied to a portion of water hose  19  extending from the distal end of boss connector  8  to snake water nozzle  20  and hose  19  through the piping connecting the vehicle&#39;s waste valve and the black tank and into the black tank interior. During flushing, both push  22  and pull  23  forces may be applied by hand  21  to a portion of water hose  19  extending from the distal end of boss connector  8  to position nozzle  20  and hose  19  within the vehicle&#39;s black tank. When flushing is complete, pull force  23  by hand  21  can be applied to retract nozzle  20  and hose  19  from the black tank and out the waste valve of the vehicle. For this, the diameter of flexible sealing washer  10  opening  11  should be large enough to allow the water hose to longitudinally traverse opening  11  of sealing washer  10  when push  22  or pull  23  forces are applied by hand  21  to water hose  19 . At the same time, the diameter of flexible sealing washer  10  opening  11  should be small enough to fit snugly around water hose  19  to form at least a leak resistant seal. Kit  1  may be provisioned with several washers with different opening diameters to accommodate different nominal water hose sizes. In general, however, the diameter of flexible sealing washer  10  opening  11  may be smaller than both the diameter of distal end opening  9  of boss connector  8  and opening  13  of fastener  12 . 
     Flexible sealing washer  10  may be formed as flexible material to allow water hose  19  to more easily longitudinally traverse washer  10  opening  11  when a force  22  or  23  is applied by hand  21  to hose  19 . In some embodiments, flexible sealing washer  10  is composed substantially entirely of flexible gum rubber. Beneficially, the gum rubber has a wiper effect on the outside of water hose  19  when pull force  23  is applied by hand  21  that tends to keep sewage that has splashed onto the water hose on the proximal side of washer  10  and within the interior of boss connector  8  and away from the operator&#39;s hand on the distal side of washer  10 . While gum rubber may be used, other materials as an alternative to or in composition with gum rubber may be used such as, for example, HNBR (rubber), silicone, felt, or nylon. 
     When flush adapter  3  is in use, fastener  12  is used to secure flexible sealing washer  10  in place at the distal end of boss connector  8  to form a leak resistant seal. After the operator has inserted the water hose through fastener  12 , flexible sealing washer  10 , and boss connector  8 , the operator may secure flexible sealing washer  10  between the distal end of boss connector  8  and fastener  12  by forming the attachment between fastener  12  and the distal end of boss connector  8 . 
     In some embodiments, fastener  12  is a nut that has internal threads  16  for forming a threaded attachment with external threads  14  of boss connector  8 . While in some embodiments fastener  12  is a threaded nut for forming a threaded connection with a threaded distal end of boss connector  8 , other types of fasteners suitable for forming a watertight connection while securing flexible sealing washer  10  at distal end of boss connector  8  may be used such as, for example, screw-based or clamp-based fasteners. 
     When flush adapter  3  is in use, distal adapter  4  may be connected to a sewer hose which is connected to a sewer drain. Alternatively, distal adapter  4  may be connected to the Sewer Extender which in turn is connected to a sewer hose which in turn is connected to a sewer drain. As yet another alternative, the distal end of flush adapter  3  may be connected directly to the telescoping body of the Sewer Extender without use of distal adapter  4 . In any case, as the black tank is flushed of sewage by water pressure emitted from water hose nozzle  20  that is located within the black tank interior, the sewage and water conveniently drain to the external sewer drain while keeping the ground and the operator generally clean of sewage and water. Thus, flush adapter  3  can be used is accomplish a sanitary flush of the vehicle&#39;s black tank. 
     In some embodiments, the distal end of boss connector  8  has a slightly flattened tapered end at the distal end of boss connector  8  that forms opening  9  of boss connector  8 . In other words, the interior diameter of the tapered end is the diameter of opening  9 . When fastener  12  is attached to the distal end of boss connector  8 , the tapered end holds flexible sealing washer  10  in place in a non-threaded channel at the interior base of fastener  12  between internal threads  16  and opening  13 . The width of the non-threaded channel may be approximately the same width or a slightly larger width as flexible sealing washer  10  such that washer  10  seats snuggly in the channel when fastener  12  is securely attached to the distal end of boss connector  8  and held in place by the tapered end of boss connector  8  to form a leak resistant seal. 
     The diameter of the flexible sealing washer  10  opening  11  may be smaller than both the diameter of boss connector  8  opening  9  and the interior diameter of the tapered end of boss connector  8  so that that the portion of flexible sealing washer  10  surrounding hose  19  can flex toward and away from fastener  12  opening  13  as push  22  and pull  23  forces are applied by hand  21  to hose  19 . While flexing in this manner, flexible sealing washer  10  remains in contact with the outer surface of hose  19  to prevent sewage from leaking out through opening  11  of washer  10  and to prevent sewage that splashes on the hose  19  from being carried out on the surface of the hose  19  when pull force  23  is applied by hand  21  to hose  19  to retract hose  19  from opening  11  of washer  10  and out through opening  13  of fastener  12 . 
     The diameter of flexible sealing washer  10  may be approximately the same as the diameter of the channel at the interior base of fastener  12  where the diameter of the channel is larger than the diameter of opening  13  of fastener  12  such that the tapered end of the boss connector  8  holds flexible sealing washer  10  in place in the channel when fastener  12  attached to the distal end of boss connector  8  with enough force that push  22  and pull  23  forces applied by hand  21  to hose  19  do not unseat washer  10  from the channel and into the interior of boss connector  8  or out through opening  13  of fastener  12 . 
     While kit  1  including flush adapter  3  may be used with recreational vehicles, motorhomes, fifth wheels, trailers, and other like vehicles, kit  1  including flush adapter  3  may be used with boats or other water floating vessels that have like lavatories or water closets and black tanks such as, for example, recreational houseboats.