Abstract:
A tub waste overflow assembly is provided that is attachable to a tub wall by means of a threaded retaining body insertable through an overflow drain aperture in a tub wall to engage a cooperatively threaded pipe fitting on the opposite side of the tub wall. A chamfered washer is provided to cooperate with the retaining body and an annular sealing gasket to produce a fluid-tight seal on the interior surface of the tub wall and provide frictional engagement with a cover member spanning the drain aperture.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to overflow waste assemblies for tubs such as bathtubs and spas, and more particularly, to an overflow waste assembly utilizing a screw-in retaining body in combination with a chamfered washer and an annular gasket to provide a reliable, water-tight seal at a variety of tub wall angles while maintaining a vertical waste drop. This invention also relates to an overflow waste assembly having a retaining body with a mold-in-place test plug. 
     2. Description of Related Art 
     The use of waste water overflow drains in tubs such as bathtubs and spas is well known. Such overflow drains are typically located at or near the maximum intended fill level of the tub and in proximity to plumbing connecting the main tub drain to a sewer line. Prior art fittings for tub waste overflows are disclosed, for example, in the following U.S. Pat. Nos. 1,010,469; 1,781,719; 2,052,565; 2,223,365; 2,243,204; and 5,890,241. Test plugs for hydraulic testing of plumbing systems are disclosed, for example, in U.S. Pat. Nos. 4,763,510; 5,507,501 and 5,890,241. 
     Tub waste overflows usually comprise some type of fitting that connects a portion of the fitting on the inside of the tub to a drain line disposed behind the tub wall. A cover plate having recesses that admit water but not foreign objects into the drain system is generally provided on the inside of the tub. Sealing gaskets are desirably utilized on both sides of the tub wall to prevent water from leaking around the fitting. Because tub wall angles can vary significantly, tub waste overflow assemblies are desirably adaptable to provide a water-tight connection when installed in tubs having different wall angles. Tub waste overflow assemblies should also be capable of being hydraulically tested following installation without having to break the tub seal. 
     SUMMARY OF THE INVENTION 
     A tub waste overflow assembly is disclosed that is attachable to a tub wall by means of a threaded retaining body insertable through an overflow drain aperture in a tub wall to engage a cooperatively threaded pipe fitting on the opposite side of the tub wall. A chamfered washer is provided to cooperate with the retaining body and an annular sealing gasket to produce a fluid-tight seal on the interior surface of the tub wall and frictionally engage a cover member spanning the overflow drain aperture. Optionally, a removable test plug is molded in place across the mouth of the retaining body to facilitate hydraulic testing following installation. 
     According to one preferred embodiment, the invention disclosed herein is a tub waste overflow assembly having a substantially cylindrical body with a threaded male end that is insertable through an aperture in a tub wall for engagement with a cooperatively threaded female end of a drain pipe elbow disposed behind the tub wall, a flange end opposite the threaded male end, a chamfered annular plastic washer disposed between the flange end of the cylindrical body and the interior tub wall, a first annular gasket underlying the plastic washer between the plastic washer and the interior tub wall, and a second annular gasket disposed between the female end of the drain pipe elbow and the exterior tub wall. 
     According to another embodiment of the invention, a tub overflow waste assembly is disclosed that is attachable to a tub through an aperture in the tub wall. The assembly comprises a retaining body having a threaded, substantially cylindrical member that is insertable through the aperture and rotatable to threadedly engage a threaded pipe fitting aligned with the aperture outwardly of the tub. A flange member is disposed adjacent to the cylindrical member interiorly of the tub wall and has an outside diameter greater than the diameter of the aperture. The flange member also has an inclined surface facing the tub wall, and a continuous axial bore through the threaded cylindrical member and the flange member. The tub overflow waste assembly also includes an annular polymeric washer having a bore coaxially aligned with the bore through the threaded cylindrical member, the bore of the annular washer having a diameter slightly greater than that of the threaded, substantially cylindrical member of the retaining body. The annular washer further comprises an interiorly facing, chamfered surface cooperatively alignable with the inclined surface of the flange member of the retaining body to create abutting contact therebetween upon full insertion of the threaded cylindrical member into the washer bore; The annular washer also has an annular gasket seating surface facing the tub wall around the aperture, an interior tub gasket cooperatively alignable with the annular gasket seating surface of the annular washer; and a cover member for the retaining body, the cover member being attachable to the annular washer by is frictional engagement. 
     According to another embodiment of the invention, a screw-in retaining body for a tub or spa overflow drain is provided that includes a selectively removable test plug that is molded in place across the mouth of the retaining body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The apparatus of the invention is further described and explained in relation to the following figures of the drawings wherein: 
     FIG. 1 is a simplified, cross-sectional elevation view of a preferred embodiment of the tub overflow waste assembly of the invention; 
     FIG. 2 is an exploded view of the tub overflow waste assembly of FIG. 1; 
     FIG. 3 is a front elevation view of a preferred embodiment of the threaded retaining body of the invention as viewed from the interior of the tub; 
     FIG. 4 is a cross-sectional side elevation view taken along line  4 — 4  of FIG. 3; 
     FIG. 5 is a detail view taken from FIG. 4; 
     FIG. 6 is a detail view taken from FIG. 5; 
     FIG. 7 is a front elevation view of a preferred embodiment of the plastic washer of the invention as viewed facing the interior of the tub from the aperture through the tub wall; 
     FIG. 8 is a cross-sectional side elevation view taken along line  8 — 8  of FIG. 7; 
     FIG. 9 is a top plan view of the plastic washer of FIG. 7; 
     FIG. 10 is a detail view taken from FIG. 9; 
     FIG. 11 is a detail view taken from FIG. 8; and 
     FIG. 12 is a detail view taken from FIG.  8 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, tub overflow waste assembly  10  of the invention preferably comprises retaining body  12 , chamfered washer  14 , interior tub gasket  16  and cover  18 . Retaining body  12  is preferably adapted for insertion through aperture  20  in tub wall  22  and for threaded engagement with internally threaded female end  24  of a pipe segment such as elbow  26  disposed behind tub wall  22 . 
     Retaining body  12  preferably comprises a substantially cylindrical bore  28 , a male threaded section  30 , an inclined annular flange  32  and a plurality of circumferentially spaced, axially extending lugs  34  opposite male threaded end  36 . Although retaining body  12  can be made of metal or a durable polymeric material, it is preferably made of a polymeric material such as acrylonitrile butadiene styrene terpolymer (“ABS”). According to a particularly preferred embodiment of the invention, a relatively thin, continuous test plug  15  is either molded in place or otherwise provided across the mouth  21  of retaining body to facilitate hydraulic testing. 
     During makeup of tub overflow waste assembly  10 , end  36  of retaining body  12  is inserted through chamfered washer  14  and interior tub gasket  16 , then through aperture  20  in tub wall  22 , through exterior tub gasket  38 , and into threaded engagement with female threads  24  of elbow  26 . Lugs  34  on retaining body  12  are useful for rotating retaining body  12  relative to elbow  26  during tightening of assembly  10 . As retaining body  12  is threaded into elbow  26 , inclined annular flange surface  32  of retaining body  12  desirably contacts and abuts against correspondingly inclined, chamfered annular surface  42  of washer  14 . 
     Chamfered washer  14  is preferably made of polypropylene or any other similarly useful, durable polymeric material and further comprises a substantially cylindrical collar section  44  adjacent to annular surface  42 . The inside diameter of cylindrical collar section  44  is desirably slightly greater than the outside diameter of male threaded section  30  of retaining body  12  to permit threaded section  30  to extend through it in a closely fitting relationship whenever inclined annular surface  32  of retaining body  12  is fully seated against inclined annular surface  42  during tightening. Chamfered washer  14  preferably has a stepped outside wall defining a flange wall  46  having an outside diameter greater than the diameter of aperture  20  through tub wall  22 , and a recessed cylinder wall  48  having a diameter slightly less than the diameter of aperture  20 . Recessed cylinder wall  48  locates chamfered washer  14  in aperture  20 . Annular flange shoulder  50  extending between sidewall sections  46 ,  48  is preferably sufficiently wide to overlap the interior surface of tub wall  22  around aperture  20  and provide sufficient surface area contacting interior tub gasket  16  to produce a fluid-tight seal relative to aperture  20  whenever retaining body  12  is tightened relative to elbow  26 . Interior tub gasket  16  is preferably made of rubber, such as ethylene propylene diamine rubber (EPDM), or any other compressible material that is similarly useful as a gasket between retaining body  12  and the interior surface of tub wall  22 . 
     Cover  18  can be made of metal or plastic, and desirably has a diameter and thickness adequate to cover retaining body  12 , chamfered washer  14  and interior sealing gasket  16 . A plurality of tabs  64  or other protrusions directed radially inward from the inside of sidewall  52  of cover  18  preferably provide frictional engagement between cover  18  and flange wall  46  or flange shoulder  50  of chamfered washer  14 . Unlike the cover portions of most prior art tub waste overflow fixtures, cover  18  will preferably have a smooth, featureless surface facing the interior of the tub because no screws are required to hold cover  18  in place over retaining body  12 . Circumferentially extending sidewall  52  of cover  18  is preferably slotted or recessed along its bottom or lower side edges, and the width of slot(s)  54  is sufficient to permit tub waste overflow to enter bore  28  of retaining body  12  behind cover  18  during use. 
     A fluid-tight seal between elbow  26  and exterior surface  58  of tub wall  22  around aperture  20  is desirably achieved using an exterior tub gasket  38 . According to one particularly preferred embodiment of the invention, elbow  26  is a 90 degree plastic pipe elbow with one 1½ inch diameter, schedule  24  female slip fitting and one 1½ inch diameter threaded female fitting. Exterior tub gasket  38  is preferably a compressible, annular gasket, most preferably made of a foamed polymeric material. Exterior tub gasket  38  desirably has an outer diameter equal to or greater than the outer diameter of flange  60  of elbow  26  and a thickness sufficient to produce a fluid-tight seal around aperture  20  of tub wall  22  when retaining body  12  is tightened relative to elbow  26 . Gasket  38  should produce a fluid-tight seal even when exterior surface  58  of tub wall  22  is inclined at an angle relative to the plane defined by end  62  of elbow  26 . Satisfactory materials for use in making exterior tub gasket  38  include, for example, closed cell polyurethane, butyl rubber or EPDM rubber. 
     Referring to FIGS. 3-6, another preferred embodiment of a retaining body  70  suitable for use in tub overflow waste assembly of the invention is shown that comprises a substantially cylindrical sidewall section  73  having a centrally disposed bore  80  defined by sidewall  74 . Annular flange  72  surrounds one end of retaining body  70  and is undercut by annular bevel  84  to facilitate engagement with plastic washer  90  as described below in relation to FIGS. 7-9 and  12 . A plurality of circumferentially spaced lugs  78  extend forwardly of flange  72  to facilitate installation and removal of retaining body  70 . Male threads  82  are desirably provided behind flange  72 . Retaining body  12  is desirably molded from a suitable polymeric material and can be made with a removable test plug  76 , preferably unitarily molded together with retaining body  70 , that seals off the end of bore  80  that is more nearly adjacent to flange  72 . Test plug  76  is beneficial for use in hydraulic testing of the installed tub overflow waste assembly without the necessity of loosening retaining body  70  and breaking either the interior or exterior tub seal. The thickness of test plug  76  is preferably adequate to resist rupture when exposed to the hydraulic pressures encountered during leak testing but susceptible to being removed following such testing. Referring to FIG. 6, a beveled recess  88  can be provided around the edges of test plug  76  to weaken the edges of the plug and facilitate its removal. Although not shown in FIGS. 3-6, it will be appreciated that a tab can also be provided on the forwardly facing surface of test plug  76  to facilitate removal subsequent to testing to reduce the likelihood that test plug  76  will fall into the drain pipe behind the tub. 
     Referring to FIGS. 7-12, another preferred chamfered washer  90  is disclosed that is similarly useful in place of washer  14 , previously described in relation to FIGS. 1 and 2, in the tub overflow waste assembly of the invention. Washer  90  is an annular washer, preferably made of injection molded plastic, most preferably polypropylene, further comprising an annular chamfer  104  inclined at an angle that provides continuous, facing contact with undercut bevel  84  of retaining body  70  whenever the threaded end of retaining body  70  is inserted through washer  90 . The narrower end of chamfer  104  is desirably contiguous with inside surface  94  of cylindrical collar portion  98 . The length and outside diameter of collar portion  98  are desirably such that collar portion  98  will locate washer  90  in the tub aperture through which the tub overflow waste assembly of the invention is installed. The thickness of collar portion  98  is preferably sufficient to locate the washer relative to the aperture, with inside surface  94  fitting snugly against the threaded portion  82  of retaining body  70 . 
     Referring more particularly to FIGS. 10-12, which show details taken from FIGS. 8 and 9, washer  90  preferably further comprises a plurality of circumferentially spaced lugs  95 , each having a stud  96  facing toward the tub wall and an oppositely facing recess  97 . In FIGS. 11 and 12, the details of washer  90  are shown in combination with interior tub gasket  110  for clarity of illustration. Lugs  95  extend radially outward beyond the periphery of inclined surface  92 , which is desirably separated from chamfer  104  by surface  102  to facilitate molding. Annular bead  100  is provided on annular gasket seating surface  108  of washer  90  and cooperates with studs  96  and outside wall  106  of collar portion  98  in locating interior tub gasket  110  relative to the aperture through the tub wall. Studs  96  also define the minimal spacing between annular gasket seating surface  108  of washer  90  and the underlying tub surface to reduce the likelihood of damaging interior tub gasket  110  and bead  100  when retaining body  70  as described above is screwed into a drain pipe fitting disposed behind the tub wall. Interior tub gasket  110  is preferably made of rubber, such as ethylene propylene diamine rubber (EPDM), or any other compressible material that is similarly useful as a gasket between retaining body  70  and the interiorly facing surface of the tub wall. 
     Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading the present disclosure, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.