Abstract:
A nested bushing coupling for attaching a plumbing component to a conduit. The assembly includes at least one or more nested bushings having off-centered openings which may be situated at various orientations within a receiver.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   Not Applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   MICROFICHE APPENDIX 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to the field of plumbing. More particularly, the present invention comprises an adjustable coupling for attaching a plumbing component to a conduit. 
   2. Description of the Related Art 
   When constructing a building with a concrete slab foundation, plumbers coordinate with other contractors to install plumbing lines and fixtures. Generally, plumbers place plumbing lines just prior to the pouring of the concrete slab. It is not uncommon for plumbing lines to shift slightly when the concrete is poured, however. Once the concrete has cured—and often after tile work has been laid—the plumber returns to attach the various plumbing fixtures to the lines. 
   Various building codes define where certain plumbing fixtures—such as toilets—must be placed. Turning to  FIG. 1 , toilet  10  is installed in a room near back wall  16  and side wall  14 . As is known to those skilled in the art, toilet  10  is connected to a drain line via closet flange  12 . Because toilet  10  attaches directly to closet flange  12 , the location of toilet  10  relative to back wall  16  and side wall  14  is determined by the location of closet flange  12  and the drain line. Closet flange  12  is attached directly to the drain pipe, so the location of closet flange  12  is non-adjustable. 
   Some building codes prescribe a distance D that the center of toilet must be from side wall  14 . Because some inspectors require precise conformity to the prescribed distance (in some cases within ¼ inch), it is important for closet flange  12  to be positioned at the correct location relative to side wall  14 . Because the drain pipe and closet flange  12  may shift when the concrete is poured, plumbers may have to break the concrete slab around the drain pipe with a jackhammer so that the drain pipe and closet flange may be shifted to the desired location. In many cases, this requires the drain pipe to be cut and “elbow” joints to be added to center closet flange  12  at the desired location. 
   The shifting of plumbing lines can also create a misalignment for plumbing lines which are to be placed within walls. Turning to  FIG. 2 , in-concrete pipe  24  shifted during the concrete pour such that part of the opening of in-concrete pipe  24  extends outside of the footprint of wall  18 . In-wall pipe  26  is designed to be placed in wall  18  between first wall boundary  22  and second wall boundary  20 . This situation requires the concrete to be broken around in-concrete pipe  24  so that in-concrete pipe  24  may be shifted into alignment with the location of in-wall pipe  26 . Once again, this can require the pipe to be cut and elbow joints added to center the pipe between first wall boundary  22  and second wall boundary  20 . 
   As such it would be desirable to provide a plumbing solution which allows for plumbing fixtures to be coupled to in-ground drain lines and placed at the desired location without having to break-up portions of the concrete foundation. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is a nested bushing coupling for attaching a plumbing component to a conduit. The assembly includes at least one nested bushing having an off-centered opening which may be situated at various orientations within a receiver. In the preferred embodiment, two bushings are used to provide greater adjustment potential. Each bushing is situated within a cylindrical passage and may be rotated within the cylindrical passage to move the location of the off-centered opening of the bushing. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a plan view, illustrating the placement of a toilet next to a side wall. 
       FIG. 2  is a plan view, illustrating the misalignment of a conduit and an in-wall pipe. 
       FIG. 3  is an exploded perspective view, illustrating the present invention. 
       FIG. 4  is a section view, illustrating the present invention. 
       FIG. 5  is a plan view, showing the present invention. 
       FIG. 6  is a plan view, illustrating the range of placement positions allowed by the present invention. 
       FIG. 7  is an exploded perspective view, showing the present invention. 
       FIG. 8  is an exploded perspective view, showing the present invention. 
       FIG. 9  is a plan view, showing how the invention may be used to align an in-wall pipe with a conduit. 
   

   REFERENCE NUMERALS IN THE DRAWINGS 
   
     
       
             
             
             
             
           
         
             
                 
             
           
           
             
               10 
               toilet 
               12 
               closet flange 
             
             
               14 
               side wall 
               16 
               back wall 
             
             
               18 
               wall 
               20 
               inside wall surface 
             
             
               22 
               outside wall surface 
               24 
               in-concrete pipe 
             
             
               26 
               in-wall pipe 
               28 
               conduit 
             
             
               30 
               increaser 
               32 
               opening 
             
             
               34 
               offset bushing 
               36 
               first passage 
             
             
               38 
               offset bushing 
               40 
               second passage 
             
             
               42 
               closet flange 
               44 
               third passage 
             
             
               46 
               lip 
             
             
               50 
               center 
               52 
               placement region 
             
             
               54 
               pipe 
               56 
               dryer vent 
             
             
               58 
               inlet 
               60 
               concrete 
             
             
               62 
               surface 
               64 
               descending tube 
             
             
                 
             
           
        
       
     
   
   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention, an adjustable coupling for attaching a plumbing component to a conduit, is illustrated in  FIG. 3 . Conduit  28  is a conduit, such as one used to transfer the contents of a toilet basin to a sewer or a septic tank. Conduit  28  may be made of various materials, but most commonly conduit  28  is made of PVC. Increaser  30  is attached to the end of conduit  28  prior to pouring the concrete foundation. Increaser  30  has opening  32  which receives one or more “nested” bushings (offset bushings  34  and  38 ) and closet flange  42 . Closet flange  42  is a simplified depiction of a closet flange. A closet flange typically has slots and holes for receiving bolts which attach the toilet to the closet flange. Opening  32  of increaser  30  is initially sealed with a knockout covering plate or some other seal to prevent concrete from spilling into conduit  28 . 
   Once the concrete is poured, the knockout covering plate is removed from opening  32 . Offset bushing  34  fits snugly into and is rotatably situated within opening  32 . Offset bushing  38  fits snugly into and is rotatably situated within first passage  36  of offset bushing  34 . Descending tube  64  of closet flange  42  fits snugly into and is rotatably situated within second passage  40 . Openings  32 ,  36 ,  38 ,  40 , and  44  are fluidly connected such that when the contents of the toilet are drained into third passage  44  the contents will pass through the assembly into conduit  28 . 
   Turning to  FIG. 4 , the reader will note that when concrete  60  is poured, increaser  30  and conduit  28  are submerged in the concrete. Surface  62  of concrete  60  is substantially level with the top of increaser  30  and the tops of offset bushing  34  and offset bushing  38 , which are placed in increaser  30  after the concrete is poured and the knockout covering plate is removed from opening  32 . Offset bushing  34  is rotatably nested in increaser  30  and rests on the narrowing throat of increaser  30 . Offset bushing  38  is rotatably nested within the opening of offset bushing  34  and rests on lip  46 . 
   As shown in  FIG. 5 , offset bushing  34  may be rotated within opening  32  of increaser  30 . Likewise, offset bushing  38  may be rotated within first passage  36  of offset bushing  34 . The rotation of either offset bushing  34  or offset bushing  38  will change the location of center  50  of second passage  40 . This feature allows the user to place center  50  at various locations after the concrete foundation has been poured and cured. 
     FIG. 6  shows the general region in which descending tube  64  of closet flange may be placed by rotating offset bushings  34  and  38 . This region is illustrated as placement region  52  in  FIG. 6 . Width W defines the difference between the location of the inside surface of increaser  30  and placement region. Width W is a function of the location of first passage  36  and second passage  40  relative to the outside facing wall of offset busing  34  and offset bushing  38 , respectively. The closer first passage  36  and second passage  40  are placed to the outside facing walls (i.e. the greater the offset from center), the smaller width W will be. Openings  36  and  40  are preferably located on the respective bushings such that placement region  52  is maximized. Openings  36  and  40  are further preferably located such that it is possible to align center  50  with the actual center of increaser  30 . 
   The reader will now appreciate how the present invention may be employed by a plumber as part of the construction process. First, the plumber places pipes within the graded ground mold consistent with the building plans. Second, concrete is poured into the ground mold. Once the concrete cures, the plumber removes the knockout covering plate from opening  32  of increaser  30 . The offset bushings are then placed in opening  32  and rotated until second passage  40  is centered at the desired location. PVC cement is then applied to the cylindrical surfaces of the bushings and the coupling is allowed to set. 
   The invention can also be used to address misalignment of plumbing conduits intended to reside within a wall.  FIG. 7  shows a single nested bushing assembly which may be used to align an in-wall pipe to a conduit. In this example, offset bushing  34  is used to fluidly connect pipe  54  (a pipe to extend vertically within a wall such as the example shown in  FIG. 2 ) to conduit  28  (an in-concrete plumbing line). As shown with the example in  FIG. 4 , increaser  30  and conduit  28  are submerged in concrete such that the surface of the concrete is substantially level with the top of increaser  30  and opening  32 . Offset bushing  34  is rotatably nested in opening  32 . First passage  36  of offset bushing  34  is offset from the center of offset bushing  34  so that the location of first passage  36  may be adjusted to a desired location. 
   An example of the advantages afforded by the adjustable coupling of the present invention is shown in  FIG. 9 . The reader will observe that conduit  28  has shifted such that its opening is partially blocked by second wall boundary  20 . The plumber may discover this misalignment after the concrete has been poured and the builders have erected the exterior and interior wall frames of the building. Because the plumber placed increaser  30  at the end of conduit  28 , the plumber can install the in-wall conduit without destroying a portion of the slab foundation. By rotating offset bushing  34  within opening  32  of increaser  30 , first passage  36  may be positioned between second wall boundary  20  and first wall boundary  22  (as shown in  FIG. 9 ). It should be noted that multiple nested bushings may be employed (such as in the previous closet flange example) if a broader range of placement tolerance is needed. 
     FIG. 8  illustrates another example of an in-wall pipe embodiment. It has become increasingly common to tie dryer exhaust vents to in-concrete exhaust lines. These are typically located in walls and experience the same misalignment problems as in-wall plumbing conduits. In  FIG. 8 , dryer vent  56  is fluidly connected with conduit  28  to vent hot air exhausted from a clothes dryer. In order to reduce backpressure, it is desirable to increase the cross-sectional area of conduits in the exhaust stream. When running a cylindrical pipe through the wall the cross-sectional area is limited by the width of the space between the inside-facing surface and outside-facing surface of the wall (e.g., second wall boundary  20  and first wall boundary  22  of  FIG. 9 ). Dryer vent  56  has a rectangular cross-section which allows the cross-sectional area to be larger than a standard cylindrical pipe. Dryer vent  56  has inlet  58  which extends through the wall and attaches to the exhaust of the dryer. The bottom of dryer vent  56  is fluidly connected to offset bushing  34 . As with the previous examples, offset bushing  34  may be rotated within opening  32  of increaser  30  for the proper alignment of first passage  36 . 
   When used for aligning in-wall conduits, the same installation procedure is used as described previously with respect to the closet flange. First, the plumber places pipes within the graded ground mold consistent with the building plans. Second, concrete is poured into the ground mold. Once the concrete cures, the builders erect the wall frames for the interior and exterior walls of the building. The plumber then removes the knockout covering plate from opening  32  of increaser  30 . The offset bushings are then placed in opening  32  and rotated until second passage  40  is centered at the desired location. PVC cement is then applied to the cylindrical surfaces of the bushings and the exterior cylindrical surface of pipe  54  and the coupling is allowed to set. 
   It is generally important that the components of the assembled coupling be attached together to form an airtight seal. If PVC is used, the components may be attached to each other with a suitable plumbing adhesive. In the embodiment of  FIG. 3 , the outside cylindrical surface of offset bushing  34  would be attached to the inside cylindrical surface of opening  32 . The outside cylindrical surface of offset bushing  38  would be attached to the inside cylindrical surface of first passage  36 , and the outside cylindrical surface of descending tube  64  would be attached to the inside cylindrical surface of second passage  40 . 
   The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.