Drain clean-out assemblies that can be used to drain the contents of a drain line prior to removing a clean-out plug mounted to the assembly or to which the assembly is mounted. The drain clean-out assembly includes clean-out plug and a device for selectively preventing and permitting drainage of a fluid through the assembly. The assembly may include a housing having oppositely-disposed first and second ends and a drain between the first and second ends and in fluidic communication with an interior of the housing, wherein the first end of the housing is configured to attach to a drain line, the preventing and permitting device is within the housing, and the clean-out plug is removably attached to the housing. Alternatively, the preventing and permitting device may be permanently mounted to the clean-out plug.

CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/957,081, filed Aug. 21, 2007, and U.S. Provisional Application No. 61/017,213, filed Dec. 28, 2007. The contents of these prior applications are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to plumbing equipment, and more particularly problems associated with cleaning a plugged sewage drain line, for example, found in a residential and commercial buildings. 
         [0003]    If a sewage drain line becomes obstructed in, for example, a residential or commercial building, the blockage is typically removed with a rod or cable inserted through a clean-out plug located at a lower end of the drain line. However, as soon as the clean-out plug is removed, backed-up sewage below the obstruction rapidly drains from the drain line as the clean-out plug is removed, often resulting in a spill that must be cleaned. 
         [0004]    U.S. Pat. No. 2,241,560 to Schouler, U.S. Pat. No. 2,451,051 to Tubbs, U.S. Pat. No. 4,159,721 to Horter, U.S. Pat. No. 5,144,699 to Graham, and U.S. Published Patent Application No. 2005/0283890 to Schaaf are each concerned with draining a drain system prior to attempting to remove an obstruction. Schouler discloses a valve between a drain system and a clean-out plug, and through which sewage can drain to a hose. Tubbs also discloses the use of a valve between a drain system and a clean-out plug assembly, though with the intent that sewage is prevented from being drained prior to and during removal of an obstruction. Horter differs in that a drain hose is attached downstream from a clean-out plug of a drain system. Graham discloses a drain hose attached downstream of a valve that operates as a drain plug on a drain system. Schaaf discloses a drain valve that, while located downstream of a drain plug, enables a drain system to be drained without removing the plug. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    The present invention provides drain clean-out assemblies that can be used to drain the contents of a drain line prior to removing a clean-out plug mounted to the assembly, or to which the assembly is mounted. 
         [0006]    According to a first aspect of the invention, the drain clean-out assembly includes a housing having oppositely-disposed first and second ends and a drain between the first and second ends and in fluidic communication with an interior of the housing. The first end of the housing is configured to attach to a drain line, and a clean-out plug is removably attached to the housing. A device is contained within the housing for selectively preventing and permitting flow of a fluid into the housing from the first end thereof and out of the housing through the drain thereof. A device outside the housing permits operation of the preventing and permitting device. 
         [0007]    According to a second aspect of the invention, the drain clean-out assembly includes a clean-out plug and a device permanently mounted to the clean-out plug for selectively preventing and permitting drainage of a fluid through the clean-out plug. The preventing and permitting device may be, for example, a spigot, a three-way ball valve, or plunger assembly within the housing. 
         [0008]    According to further aspects of the invention, a method is provided for draining an obstructed drain line to permit removal of an obstruction in the drain line. The method generally entails mounting to a drain line a drain clean-out assembly that includes a device for selectively preventing and permitting flow of a fluid from a first end of a housing of the assembly to a drain on the housing. The device is then operated to drain sewage within the drain line downstream of (below) the obstruction, after which a clean-out plug associated with the assembly is removed to gain access to and remove the obstruction through an access in the housing. 
         [0009]    In view of the above, the drain clean-out assembly enables the draining of a plugged drain line downstream of (below) the obstruction prior to attempting to remove the obstruction itself. As a result, a cable or rod can be inserted into the drain line through a clean-out plug without risk of sewage spilling out as the clean-out plug is being removed. Other objects and advantages of this invention will be better appreciated from the following drawing descriptions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIGS. 1 and 2  are perspective and cross-sectional views, respectively, of a plunger-type drainable clean-out assembly in accordance with a first embodiment of the invention. 
           [0011]      FIGS. 3 and 4  are cross-sectional views of plunger-type drainable clean-out assemblies in accordance with second and third embodiments of the invention. 
           [0012]      FIGS. 5 and 6  are perspective and cross-sectional views, respectively, of a ball valve-type drainable clean-out assembly in accordance with a fourth embodiment of the invention. 
           [0013]      FIG. 7  is a perspective view and  FIGS. 8A , and  8 B are cross-sectional views of a ball valve-type drainable clean-out assembly for a drain stack in accordance with a fifth embodiment of the invention. 
           [0014]      FIGS. 9 and 10  are perspective and cross-sectional views, respectively, of a spigot-type drainable clean-out assembly for a drain stack in accordance with a fifth embodiment of the invention. 
           [0015]      FIG. 11  is a cross-sectional view of a plunger-type drainable clean-out assembly in accordance with a sixth embodiment of the invention. 
           [0016]      FIGS. 12 and 13  are perspective and cross-sectional views, respectively, of a ball valve-type drainable clean-out assembly in accordance with a seventh embodiment of the invention. 
           [0017]      FIGS. 14 and 15  are perspective and cross-sectional views, respectively, of a ball valve-type drainable clean-out assembly in accordance with an eighth embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]      FIGS. 1 through 15  depict configurations of drainable clean-out assemblies in accordance with embodiments of this invention. In each embodiment, the assembly is configured to be mounted to a drain line (or stack), and is equipped with a clean-out plug and a drain valve for safely draining sewage from a drain line before attempting to place a rod or cable into the drain line to remove a blockage. In the figures, consistent reference numbers are used to identify functionally similar structures of related embodiments. It should be further noted that the drawings are drawn for purposes of clarity when viewed in combination with the following description, and therefore are not necessarily to scale. 
         [0019]      FIGS. 1 and 2  represent an embodiment of a plunger-type clean-out assembly  10  of this invention, and  FIGS. 3 and 4  represent two additional embodiments of plunger-type clean-out assemblies  10  similar in function and operation to the embodiment of  FIGS. 1 and 2 .  FIG. 2  further shows the assembly  10  of  FIG. 1  mounted to a sewer line  50  in which an obstruction  52  is present. The assemblies  10  are typically located at or near an end of the sewer line  50  below drain pipes (not shown) that enter the sewer line  50  from above. In a conventional plumbing system, a clean-out plug would be employed to close the end of the sewer line  50  instead of the assembly  10  of this invention. 
         [0020]    The clean-out assemblies  10  if  FIGS. 1 through 4  enable the obstruction  52  to be removed from the sewer line  50 , while avoiding sewage  54  downstream of (below) the obstruction  52  from pouring out of the line  50  when the line  50  is opened to permit insertion of a rod or cable (not shown) to remove the obstruction  52 . In  FIGS. 1 through 4 , the assembly  10  comprises a generally cylindrical-shaped housing  12  having oppositely-disposed axial ends, one of which is a mounting end  14  adapted to secure the assembly  10  to the sewer line  50 , while the other is a clean-out end  16  equipped with a clean-out plug  18 . The mounting end  14  is shown equipped with threads that permit mounting the assembly  10  on the drain line  50 , though an adhesive, clamp, expansion seal, or other mounting technique could be used instead. At a lower side of its circumference, the housing  12  is equipped with a drain  20  whose axis is oriented generally as a radial to the axis of the housing  12 . 
         [0021]    The assemblies  10  of  FIGS. 1 through 4  further include a plunger assembly  22  with a piston  24  slidably disposed within the housing  12 . The piston  24  has a convex face  26  shaped to abut and seal against an annular-shaped tapered seat  28  defined at the junction between the mounting end  14  of the housing  12  and the main body of the housing  12 . In this manner, the piston  24  is capable of sealing the sewage  54  within the drain line  50  and preventing its entry into the housing  12 . 
         [0022]    In  FIGS. 1 and 2 , the plunger assembly  22  further includes a stem  32  that threads through a threaded bore  34  in the clean-out plug  18 . A nut  36  affixed to the stem  32  enables the stem  32  to be turned and threaded out through the plug  18 , thereby backing the piston  24  off the seat  28  to permit the sewage  54  to enter the housing  12 . The threaded engagement of the stem  32  and clean-out plug  18  effectively forms a seal to prevent leakage of sewage  54 . It is foreseeable that the threads could be omitted, and the stem  32  and bore  34  could have a sliding fit therebetween that could be sealed with o-rings or another suitable sealing element. In the absence of threads, the assembly  10  would preferably be equipped with a spring or other element capable of biasing the piston  24  into engagement with the seat  28 . 
         [0023]    The embodiments of  FIGS. 3 and 4  differ primarily by the configuration of the plunger assembly  22 . In  FIG. 3 , the plunger assembly  22  further includes a threaded cylinder  40  within a boss  42  on the clean-out plug  18 . By turning the cylinder  40  with a handle  44 , the plunger assembly  22  is retracted in the housing  12  essentially in the same manner as that seen in  FIG. 2 . In  FIG. 4 , the plunger assembly  22  can be a solid or hollow body attached to or otherwise formed as a fixed extension of the clean-out plug  18 , such that rotating the plug  18  (for example, using a wrench on the boss  42 ) to partially retract the plunger assembly  22  within the housing  12  also rotates the plunger assembly  22 , thereby unseating the piston  24  and its convex face  26  from the seat  28  for draining the sewage  54 . 
         [0024]    In each of  FIGS. 1 through 4 , the drain  20  is equipped with a drain plug  38  that can be removed prior to releasing the sewage  54  from the drain line  50 , so that the sewage  54  can safely drain from the housing  12  into a hose (not shown) or other conduit threaded into or otherwise attached to the drain  20 . Once the sewage  54  has been drained from the housing  12  through the drain  20 , the clean-out plug  18  (along with the plunger assembly  22 ) can be removed from the housing  12  to permit the insertion of a rod or cable through the clean-out end  16  of the housing  12  to remove the obstruction  52 . The housing  12  can remain on the drain line  50 , enabling continued use of the drain  20  (and any conduit attached thereto) to remove sewage  54  from the drain line  50  as the obstruction  52  is being removed and sewage is displaced by the rod/cable. 
         [0025]    While each clean-out plug  18  in  FIGS. 1 through 4  is shown with male threads that thread into female threads within the clean-out end  16  of the housing  12 , those skilled in the art will appreciate that the plug  18  could be equipped with female threads that thread onto male threads on the circumference of the clean-out end  16 . Furthermore, while a male boss  42  is shown for turning the plug  18 , the end of plug  18  could be countersunk with a feature (for example,  43  in  FIG. 4 ) to permit the use of a ratchet, screwdriver, or any other suitable tool to rotate the plug  18  and eventually remove it from the housing  12 . 
         [0026]      FIGS. 5 and 6  represent an embodiment of a ball valve-type clean-out assembly  60  of this invention. Similar to the embodiments of  FIGS. 1 through 4 , the assembly  60  is adapted to be mounted to a sewer line (for example,  50  in  FIG. 2 ). The assembly  60  comprises a generally cylindrical-shaped housing  62  having oppositely-disposed axial ends, one of which is a mounting end  64  adapted to secure the assembly  60  to the sewer line while the other is a clean-out end  66  equipped with a clean-out plug  68 . Similar to the embodiments of  FIGS. 1 through 4 , the mounting end  64  can be equipped with threads that permit mounting the assembly  60  on a drain line, and the housing  62  is equipped with a drain  70  located at a lower side of its circumference. The drain  70  can be closed with a drain plug (not shown), similar to  FIGS. 1 and 2 . 
         [0027]    The primary difference between the assembly  60  of  FIGS. 5 and 6  and the assemblies  10  of  FIGS. 1 through 4  is the use of a three-way ball valve  72  instead of a plunger assembly  22  to regulate the flow of sewage through the assembly  60 . The ball valve  72  (shown only in  FIG. 6 ) has a main axial bore  74  and a radial bore  76 , the latter of which is coaxial with the rotational axis of the valve  72  and therefore is and remains aligned with the drain  70  throughout the operation of the assembly  60 . When the ball valve  72  is closed, the axial bore  74  is oriented transverse to the axis of the housing  62 , such that the body of the ball valve  72  closes the mounting end  64 , thereby sealing sewage within the drain line and preventing its entry into the housing  62 . By turning the ball valve  72  with a handle  78  to align the axial bore  74  with the axis of the housing  62 , sewage is able to enter the bore  74  and exit the housing  62  through the radial bore  76  and drain  70 . As before, a hose or other conduit can be threaded onto or otherwise attached to the drain  70 . Once the sewage has been drained from the housing  62 , the clean-out plug  68  can be removed from the housing  62  to permit the insertion of a rod or cable into the drain line through the clean-out end  66  of the housing and the axial bore  74  of the valve  72 . The housing  62  can remain on the drain line, enabling continued use of the drain  70  (and any conduit attached thereto) to remove sewage from the drain line as the obstruction is being removed and sewage is displaced by the rod/cable. 
         [0028]      FIGS. 7 ,  8 A and  8 B represent the adaptation of a ball valve-type clean-out assembly  80  to a vertical section of a drain stack  100 , such as of a type typically found in commercial buildings. Similar to the embodiments of  FIGS. 1 through 6 , the assembly  80  comprises a generally cylindrical-shaped housing  82  with oppositely-disposed axial ends  84  and  86 , both of which are adapted to secure the assembly  80  to the stack  100 . Similar to the previous embodiments, the ends  84  and  86  can be attached with threads, clamps, expansion seals, adhesives, etc., to the drain stack  100 , and the housing  82  is equipped with a drain  90  located at its circumference. The drain  90  is shown closed with a drain plug  91 . 
         [0029]    The housing  82  contains a modified three-way ball valve  92  (shown only in  FIGS. 8A and 8B ) with a main axial bore  94  and a radial bore  96  coaxial with the rotational axis of the valve  92 , such that the radial bore  96  is and remains aligned with the drain  90  throughout the operation of the assembly  80 . In contrast to the embodiment of  FIGS. 5 and 6 , the ball valve  92  is normally open ( FIG. 8A ) during the operation of the plumbing system, with the axial bore  94  oriented in-line with the axis of the housing  82  to permit downward flow of sewage through the housing  82  and into the section of the stack  100  beneath the housing  82 . Because sewage is normally present within the drain stack  100  and the housing  82 , the radial bore  96  is also filled with sewage under a pressure head from the sewage above the valve  92 . As seen in  FIG. 8B , by turning the ball valve  92  about ninety degrees with a handle  98 , the axial bore  94  is no longer aligned with the axis of the housing  82  and the radial bore  96  is effectively isolated from the sewage above the ball valve  92 . Consequently, the drain plug  91  can be removed to permit attachment of a hose or other conduit (not shown) to the drain  90 , with any spillage being limited to the small amount within the bores  94  and  96 . Thereafter, the ball valve  92  can be returned to the position in  FIG. 8A  to allow sewage above the valve  92  to flow downwardly through the axial bore  94  and then through the radial bore  96  to exit the housing  82  through the drain  90  and its attached conduit. Once the sewage has been drained from the housing  92  through the drain  90 , a clean-out plug  88  located above the valve  92  can be removed from the housing  82  to permit the insertion of a rod or cable into the drain stack  100 . During removal of the obstruction, the drain  90  (and any conduit attached thereto) continues to remove sewage from the drain stack  100  as the obstruction is being removed and sewage is displaced by the rod/cable. 
         [0030]    The embodiments of  FIGS. 9 through 15  differ from the preceding embodiments in part due to the drainage mechanism effectively being a permanent component of a clean-out plug, instead of a clean-out plug being a removable component of the clean-out assembly. 
         [0031]      FIGS. 9 and 10  represent a clean-out assembly  110  configured for use as a clean-out or drain plug  118  equipped with a spigot  122  and adapted to be attached (e.g., threaded) to a drain line (e.g.,  50  in  FIG. 2 ), such as with threads, clamps, expansion seals, adhesives, etc. The spigot  122  has a drain  120  that is preferably configured to permit the attachment of a garden hose or other suitable conduit. In use, the spigot  122  is simply opened to drain sewage from the sewer line downstream of an obstruction, and once drained the plug  118  (along with the entire spigot  122  mounted thereto) can be removed from the drain line, or a separate clean-out plug upstream of the plug  118  can be removed, to permit the insertion of a cable or rod into the drain line without risk of sewage spilling out as the plug  118  (or the separate clean-out plug) is being removed. 
         [0032]      FIG. 11  also represents a clean-out assembly  160  configured for use as a clean-out or drain plug  168 . The assembly  160  of  FIG. 11  primarily differs from that of  FIGS. 9 and 10  by replacing the spigot  122  with a housing  162 , drain  170 , and plunger assembly  172  mounted transverse to the housing  162 . Similar to the plunger-type embodiments of  FIGS. 1 through 4 , the plunger assembly  172  includes a threaded stem  182  threaded through a threaded bore  184  of the housing  162 , and a piston  174  attached to the end of the stem  182  within the housing  162 . The piston  174  is adapted to abut and seal against a seat  178  surrounding the drain  170 . A slotted head  186  opposite the piston  174  and outside the housing  162  enables the stem  182  to be turned and threaded out through the housing  162 , thereby backing the piston  174  off the seat  178  to permit sewage to flow through the housing  162  and drain out through the drain  170 . Once the drain line is drained of sewage, the entire plug  168  (including the plunger assembly  172  within) can be removed from the drain line, or a separate clean-out plug upstream of the plug  118  can be removed, to permit the insertion of a cable or rod into the drain line without risk of sewage spilling out as the plug  168  (or the separate clean-out plug) is being removed. 
         [0033]    Finally,  FIGS. 12 through 15  represent clean-out assemblies  210  and  260 , respectively, configured for use as clean-out or drain plugs  218  and  268 . These assemblies  210  and  260  primarily differ from that of  FIG. 11  by replacing the plunger assembly  172  with a three-way ball valve  222 . The ball valve  222  is encased in a housing  212  equipped with a drain  220  at its lower edge, with one end  214  of the housing  212  coupled to the plug  218 / 268  and the opposite end  216  closed. The embodiments of  FIGS. 12 and 13  and  FIGS. 14 and 15  differ primarily by the size of the housings  212  and their internal components relative to their respective plugs  218  and  268 . 
         [0034]    Similar to the ball valve-type embodiments of  FIGS. 5 and 6 , each ball valve  222  has a main axial bore  224  and a radial bore  226 , the latter of which is coaxial with the rotational axis of the valve  222  and therefore is and remains aligned with the drain  220  throughout the operation of the assembly  210  and  260 . When the ball valve  222  is closed, the axial bore  224  is oriented transverse to the axis of the housing  212 , such that the body of the ball valve  222  closes the mounting end  214  of the housing  212 , thereby sealing sewage within the drain line and preventing its entry into the housing  212 . By turning the ball valve  222  with a handle  228  to align the axial bore  224  with the axis of the housing  212 , sewage is able to enter the bore  224  and exit the housing  212  through the radial bore  226  and drain  220 . Once the drain line is drained of sewage, the entire plug  218  or  268  (including the ball valve  222  within) can be removed from the drain line, or a separate clean-out plug upstream of the plug  218  or  268  can be removed, to permit the insertion of a cable or rod into the drain line without risk of sewage spilling out as the plug  218  or  268  (or the separate clean-out plug) is being removed. 
         [0035]    In the embodiments of  FIGS. 1 through 15 , conventional plumbing-grade materials can be used to form the components of the assemblies  10 ,  60 ,  80 ,  110 ,  160 ,  210  and  260 . In  FIGS. 1 through 4  and  11 , the pistons  24  and  174  or at least their sealing faces  26  and  176  may be formed of rubber or another pliable material. 
         [0036]    While the invention has been described in terms of specific embodiments, it is apparent that other forms could be adopted by one skilled in the art. For example, the invention could be employed on drain lines and stacks of essentially any diameter, the functions of each component of the fittings could be performed by components of different construction but capable of a similar (though not necessarily equivalent) function, the fittings could differ in appearance and construction from the embodiments shown in the Figures, and appropriate materials could be substituted for those noted. Accordingly, it should be understood that the invention is not limited to the specific embodiments illustrated in the Figures. It should also be understood that the phraseology and terminology employed above are for the purpose of disclosing the illustrated embodiments, and do not necessarily serve as limitations to the scope of the invention. Instead, the scope of the invention is to be limited only by the following claims.