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This application is a continuation-in-part of prior U.S. application Ser. No. 10/112,844, filed Mar. 28, 2002 now U.S. Pat. No. 6,618,875. 

   BACKGROUND OF THE INVENTION 
   This invention relates generally to bath waste plumbing equipment, and more particularly retention of waste water outlet covers to terminals or outlets of plumbing fittings, as well as provision and use of caps for pressure testing of plumbing lines leading to such outlets. 
   There is continual need for improvements in such bath waste plumbing equipment, facilitating ease of application of such outlet covers to plumbing terminals as at bath or shower walls and removal of such covers; and there is need for equipment facilitating pressure testing of such plumbing lines leading to such terminals. No prior equipment of which we are aware incorporates the novel and highly useful cover and mounting structure of the present invention, or its functioning and improved results obtained. Also, no prior equipment of which we are aware incorporates the cover holding structure as will appear. 
   SUMMARY OF THE INVENTION 
   It is a major object of the invention to provide highly useful improvements in plumbing equipment as referred to above. Basically, the invention is incorporated in a retention and/or positioning system or apparatus for a tubular terminal cover, the tubular terminal being a part of a plumbing fitting. Such a tubular terminal or part projects through an opening in a wall, and typically defines grooving such as threading. One aspect of the invention comprises 
   a) a cover extending in registration with such grooving, 
   b) and a retainer carried by the cover and projecting to locally engage such grooving, thereby to position the cover in relation to the grooving. 
   The cover is typically positioned to resist inadvertent rotation and/or loosening. 
   It is another object to provide for ease of manipulation of the retainer (as for example into or out of operating position). this may be facilitated by providing a slot in the cover, a bridge extending across the slot, and the retainer carried by the bridge to project toward and to penetrate a local portion of the grooving, such a threading, on the tubular terminal. 
   It is another object to provide the bridge to extend in the plane of the slot, or offset relative to that plane, to diminish easy access to the retainer in the form of a set screw, thereby to prevent inadvertent access to and loosening of the set screw, as for example during cleaning of such plumbing. 
   Yet another object includes provision of retention system for holding and mounting a cover cap to a plumbing fitting having a tubular terminal that projects at an opening through a bath or shower wall, and including said cap, comprising 
   a) a retainer ring fitting on said tubular terminal and tightenable toward said wall, 
   b) a series of retention cams on said ring and spaced about a longitudinal axis defined by the ring, there being gaps between successive cams, and there being retention shoulders on the cams, 
   c) said retention shoulders facing in directions toward said wall, for retaining holders on the cover cap, after said holders have been passed longitudinally through said gaps and after the cap has been then rotated to cause said holders to slidably engage the cams and become wedged against said retention shoulders, 
   d) and a positioner carried by said cap and projecting to locally engage grooving associated with said tubular terminal. 
   An additional object is to provide a method of pressure testing a plumbing fitting having a tubular terminal that projects at an opening through a wall, that includes
         i) providing and connecting a pressure test cap to said terminal to engage an annular seal between the cap and at an end face of the tubular terminal, thereby to seal off the tubular terminal,   ii) applying internal fluid pressure to the fitting to determine if any fitting leakage exists,   iii) removing the pressure test cap from the terminal,   iv) subsequently providing a cover cap onto the tubular terminal to allow fluid leakage through the cover cap,   v) and thereafter providing and locating a positioner or holder to project through the cover cap and into local engagement with grooving associated with the tubular terminal.
 
In this regard, the cover cap may incorporate a water drainage slot, and an associated bridge, and the positioner may be located to extend through the bridge.
       

   These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: 

   
     DRAWING DESCRIPTION 
       FIG. 1  is a simplified showing, in elevation, waste plumbing leading from a tub or shower wall opening; 
       FIG. 2  is an enlarged elevation, partly broken away, and taken on lines  2 — 2  of  FIG. 1 ; 
       FIG. 3  is a section taken in elevation on lines  3 — 3  of  FIG. 2 ; 
       FIG. 4  is a frontal view taken in elevation, showing a retainer ring, as is also seen in section in  FIG. 3 ; 
       FIG. 5  is an edge elevation view taken on lines  5 — 5  of  FIG. 4 ; 
       FIG. 6  is a section taken through the retainer ring, on lines  6 — 6  of  FIG. 4 ; 
       FIG. 7  is a section taken on lines  7 — 7  of  FIG. 5  to show holder retention structure; 
       FIG. 8  is an axial elevation showing cap skirt and holder structure; 
       FIG. 9  is a section taken on lines  9 — 9  of  FIG. 8 ; 
       FIG. 10  is an axial view showing forward passage of holders on the cap skirt through gaps between circularly successive cams on the retainer ring; 
       FIG. 11  is a view like  FIG. 10 , but taken after the cap has been rotated to move the holders into wedged, cap retention position; 
       FIG. 12  is a further enlarged fragmentary view taken on lines  12 — 12  of  FIG. 11 , to show holder wedging; 
       FIG. 13  is a section like  FIG. 3 , but showing a pressure test cap in retained and sealing position on the plumbing tubular terminal; 
       FIG. 14  is an axial view showing the seal ring carried by the pressure test cap; 
       FIG. 15  is a side view of a modified cap; 
       FIG. 16  is a section taken on lines  16 — 16  of  FIG. 15 , together with a set screw holding the cap against rotation; 
       FIG. 17  is a view like  FIG. 16 , showing a modification; 
       FIG. 18  is an end view taken on lines  18 — 18  of  FIG. 15 ; and 
       FIG. 19  is a side view showing cover engagement with a nut. 
   

   DETAILED DESCRIPTION 
     FIGS. 1 and 3  show a cover cap  10  retained in position to cover a tubular terminal  11   a  of a plumbing line  11 , projecting at or through an opening  12  in a bath or shower wall  13 . A bath wall is illustrated, but is also representative of a shower wall. Merely for purposes of illustration, waste water plumbing line  11  may be connected by elbow  15  to a vertical duct  16 , to which a tee  17  is connected. An outlet  18  at the tub or shower bottom wall  19  is also connected to the tee, as by waste line  20 . 
   As shown in  FIG. 3 , a retainer ring  21  is fitted on terminal  11   a.  Such fitting may incorporate external threading  22  on  11   a,  and internal threading  23  on the ring, whereby the ring can be tightened toward wall  13 , to frictionally position the ring adjacent the wall, as shown at  13   b.    FIG. 4  shows wrench flats  21   d  circularly spaced apart on the ring  21 , and engageable by a wrench to facilitate such tightening. 
   In accordance with an important feature of the invention, the preferred ring  21  carries a series of like retention cams  24  spaced apart by gaps  25 , and projecting outwardly at circularly spaced positions or intervals, about longitudinal axis  27  defined by the ring  21 . Retention shoulders  29  are defined by the cams, at their sides which face wall  13 , and are typically angled at angle α relative to axis  27 , as seen in  FIG. 12 . Shoulders  29  face toward wall  13 , due to such angling. 
   The decorative cover cap  10 , which conceals the ring  21 , terminal  11   a  and threading  22  and  23 , is adjustably retained to ring  21  as by a circularly spaced series of holders  30  formed on or carried by the cap skirt  10   a.  Such holders may comprise small lips, best seen in  FIGS. 8 and 9 , spaced circularly at angular intervals β, about axis  27 . Three such lips, spaced at 0°, 120° and 240° about axis  27  are shown. Their width “ω” is such as to enable their passage through the gaps  25 , as shown in  FIG. 10 , at the time of assembly of the cover cap to the ring  21 . Once having passed through such gaps, the holders are in proximate or adjacent relation to wall  13 ; but the clearance are such as to allow cap and holder rotation as in direction  32  in  FIG. 10 , to wedgingly engage the cams  24 . One way to accomplish this is to configure the holder lips  30  with surfaces  30   a  angled to wedgingly engage the retention shoulders  29  of the cams, as seen in  FIG. 12 . The interengagement is frictionally, and may allow for continued rotation of the cap to advance the holders beyond the interengaged cams, and to bring the holders into registration with the next in sequence gaps  25 , enabling axial removal of the cap  10  from the ring  21 . Reverse rotation of the cap also accomplishes the same objective. Accordingly, an easily installed and easily removed decorative and protective cap is provided for, the ring  21  also being easily installed and removed, as described. 
     FIGS. 13 and 14  show a pressure test cap  40  thread connected at  41  to the tubular terminal  11   a,  without requiring removal of ring  21 . An annular seal  42  carried by that cap is brought into sealing engagement at  43  with the end face  11   b  defined by the plumbing terminal  11   a,  by tightening of the cap in the position shown. The construction allows quick removal of decorative cap  10 , and quick installation of pressure test cap  40 , for a testing of the plumbing for leaks. The method of testing a plumbing fitting having a tubular terminal that projects at an opening through a wall, includes:
         i) providing and rotatably connecting a pressure test cap to said terminal to engage an annular seal between the cap and on an end face of the tubular terminal, thereby to seal off said tubular terminal,   ii) applying internal fluid pressure to the fitting to determine if any fitting leakage exists,   iii) rotatably removing the pressure test cap from the terminal,   iv) and providing and rotatably connecting a cover cap onto said tubular terminal to allow fluid leakage through the cover cap.       
   It will be understood, that the construction of the assembly is such as to allow associated use (application and removal) as described for both protection of the plumbing terminal, and pressure testing of the plumbing, and also for quick removal of  10  and quick installation of  40 , as referred to. 
   A passage  50  in the skirt of  10   a  of the cap  10 , allows for drainage of any water collecting in the cap, and the cap can be applied to direct passage  50  downwardly. See  FIGS. 1 and 3 . Air or bath water can enter via passage  50 , as indicated by arrows  52 . 
   Referring now to  FIGS. 15 and 16 , a modified cover up  119  is like cap  19 , and serves the same functions. It has a through slot or cut-out  140  or passage cut or formed in the cap annular skirt  119   a.  Slot  140  is preferably elongated arcuately about the cap axis  141 . A bridge  142  extends widthwise across the slot, and may be integral with cap skirt section  119   b  and  119   c,  as shown. The cap end wall is shown at  119   d,  and is in alignment with part  11 . The bridge is located in an arcuate plane defined by the slot, or parallel to the slot. 
   As shown in  FIGS. 15 and 16 , a threaded hole  148  formed in bridge  142  is adapted to receive a positioner, as for example a set screw  143 , threadably engaging the hole threaded bore. The length of the fastener stem  143   a  is such as to allow penetration at  145  of the fastener tip  143   b  into grooving, as for example thread 22 of 11. Tightening of the set screw serves to anchor the cap against inadvertent rotation and/or re-positioning that could result in inadvertent cap removal. The cap is typically otherwise retained in position by lips  160 , corresponding to lips  30  referred to above. See  FIG. 18 . 
     FIG. 17  shows provision of a bridge  150  that has an intermediate wall section  150   a  that is downwardly offset toward the cap axis  151 . 
     FIG. 19  shows a modified cover cap  170  having a skirt  171  with a protruding angle local edge portion  171   a.  The latter engages an angled or grooved edge  172   a  of nut  172 , corresponding to nut  21 . That local engagement serves to also or alternatively provide a means to resist cap inadvertent rotation.

Summary:
A plumbing fitting attachable to a wall that defines an opening, comprising a tubular part sized to project through an opening, there being grooving associated with the part; a cover extending in registration with the grooving; and a retainer caused by the cover and projecting to locally engage the grooving, thereby to position the cover in relation to the grooving.