Patent Publication Number: US-7914052-B1

Title: Splined connector for a position-sensitive device such as a showerhead

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Reference is made to my co-pending U.S. patent application Ser. No. 11/465,648, filed Aug. 18, 2006, now abandoned, which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     The field is fluid couplings, in particular connectors for use in mounting showerheads or other position-sensitive devices such as fluid couplings and pipes to threaded supply lines. 
     2. Prior Art 
     Fluid couplings are used to connect a pipe or other fluid conveying device to another pipe or utilization device, such as a showerhead or faucet. It is desirable and usually essential that such a fluid coupling be able to prevent relative rotation between the two connected devices. For example it is important that a showerhead not rotate about the axis of its water supply pipe; otherwise, water exiting the showerhead could be misdirected or the showerhead could tilt to an undesirable position. Heretofore various fluid couplings for preventing such rotation were known. 
     Mueller, in U.S. Pat. No. 1,512,298 (1919), shows a pipe union with corrugations on one mating face to resist rotation through the use of friction between two pipe segments. 
     Syverson, in U.S. Pat. No. 3,064,998 (1957), shows a coupling for a grease gun in which two facing surfaces within the coupling have teeth or serrations that prevent relative rotation of the two halves. 
     In U.S. Pat. No. 3,563,469 (1969), Stacey shows a spray showerhead having internal splines that are used to create a spray effect. 
     Williams, in U.S. Pat. No. 4,674,774 (1984), shows a coupling having rotation prevention means comprising a ring of cavities or depressions on two facing members and a ball that is placed in two mating cavities to prevent rotation. 
     Lipski, in U.S. Pat. No. 4,964,573 (1989), shows a showerhead adapter in which the angle of a showerhead handle can be adjusted and locked. This concept is similar to Syverson&#39;s. 
     Kirchner et al., in U.S. Pat. No. 5,586,791 (1995), show a push-fit, splined connector for joining a fluid supply line and a pipe in a non-rotatable manner. 
     In U.S. Pat. No. 6,651,939 (2000), Bischoff et al. show a showerhead holder comprising a wall-mountable bracket and a body that can be oriented as desired then locked together using mating teeth. 
     Mack et al, in published U.S. application 20020175519, show an anti-rotation arrangement for a submersible well pump comprising a coupling with mating teeth on facing surfaces. 
     In published U.S. application 20020035752, Gransow et al show a two-head shower fixture with splines that prevent pivoting of the U-tube that holds the heads. 
     Macan et al., in published U.S. application 20050283904, show a positionable shower arm with internal splines for locking the arm in position. 
     The prior-art couplings described above generally prevent relative rotation of the coupled conduits. Some of these couplings relied on friction or interfering serrations on facing surfaces, but those are prone to eventual misalignment as their frictional surface wears or if the force holding the two halves together is reduced. Other prior-art couplings relied on pressure between a washer and the shower pipe. If these were over-tightened, the washers could fail and the seal became compromised. 
     SUMMARY 
     In accordance with one aspect of a preferred embodiment, a fluid coupling is characterized by the use of a keyed or geared spline and an enclosing tightening collar that allow a showerhead to be positioned and held in any orientation without damaging a washer seal. 
    
    
     
       DRAWING FIGURES 
         FIG. 1  is a perspective, exploded view of a connector showing one embodiment of a fluid coupling that will prevent relative rotation between the coupled conduits. 
         FIG. 2  shows the embodiment of  FIG. 1  in use. 
       
         
           
             
                 
               
                 
                     
                 
                 
                   REFERENCE NUMERALS 
                 
                 
                     
                 
               
              
                 
                     
                 
              
             
             
                 
                 
                 
                 
              
                 
                     
                   100 Showerhead assembly 
                   105 Pipe 
                   110 Nut 
                 
                 
                     
                   115 Threads 
                   116 Lumen 
                   120 Section 
                 
                 
                     
                   124 Facet 
                   125 Sealing O-ring 
                   126 Wall 
                 
                 
                     
                   130 Threads 
                   135 Collar 
                   140 Threads 
                 
                 
                     
                   142 Shoulder 
                   144 Wall 
                   145 Port 
                 
                 
                     
                   146 Branch 
                   147 Branch 
                   148 Arm 
                 
                 
                     
                   149 Arm 
                   150 Threads 
                   155 Section 
                 
                 
                     
                   160 Wall 
                   165 Orifice 
                   200 Harp 
                 
                 
                     
                   205 Showerhead 
                   210 Valve 
                 
                 
                     
                     
                 
              
             
           
         
       
     
    
    
     FIRST EMBODIMENT 
     Description 
     FIG.  1   
       FIG. 1  shows an exploded, perspective view of a showerhead assembly  100 , fluid coupling, or pipe that is to be mounted on a supply pipe  105 . In the present embodiment, a hollow nut  110  is interposed between assembly  100  and pipe  105 . Nut  110  includes center portion with a tool-gripping surface with the usual six external nut flats or facets  124  to facilitate gripping and tightening or loosening the nut. Starting from its upstream end distal from the user but on the right and closer side in the paper, nut  110  has a rear shoulder  122 , a lumen  116  containing internal female threads  115 , a projecting or wall section  126  on its downstream end having on its outside (a) a keyed or splined section  120  comprising a series of longitudinal external ribs, preferably having a triangular cross section, and (b) a sealing resilient 0-ring  125 . 0-ring  125  is seated within a groove wall portion  126 . The outer diameter of 0-ring  125  is greater than the outer diameter of wall portion  126  by a small amount, typically one mm. Such seals are well known to those skilled in the art of fluid couplings. External facets  124  are suitable for transmitting torque applied by a wrench or pliers to facilitate tightening nut  110  on pipe  105 . In lieu of such facets, the external surface of the nut can be smooth or knurled; such a surface can be grasped by a pipe wrench. 
     Supply pipe  105  terminates at the showerhead end in male threads  130 . A collar  135 , having female threads  140  and an internal shoulder  142  is slidably mounted on pipe  105 . 
     Assembly  100  includes an inlet or port  145  with external male threads  150 . Threads  150  are of the same diameter and pitch as threads  140  on collar  135 . Port  145  further includes in its interior, starting from the entry or upstream end, a wide plain wall section  144  followed by a narrower splined or keyed section  155 , followed in turn by a plain inner wall  160  that extends into an orifice  165  for admitting water from pipe  105  to the interior of assembly  100 . The diameter of inner wall portion  160  is sized to slidably admit wall portion  126  of nut  110  while compressing O-ring  125  between wall portion  160  and wall portion  126 . The teeth or keys within splined section  155  are sized to slidably and conformingly mate with those in splined section  120 . 
     The outer diameter of pipe  105  is typically 1.9 cm. Spline section  120  had 18 triangular ribs, with each rib being about 1 mm high. The number of splines can be increased for greater resolution of alignment. All other components in  FIG. 1  are scaled accordingly. Collar  135 , nut  110 , and assembly  100  can be made of a metal such as brass or stainless steel, of a sturdy plastic, or even a ceramic material. 
     Port  145  communicates with left and right branches  146  and  147  which in turn are connected to two shower arms  148  and  149  which form a harp  200  ( FIG. 2 ) that holds a large showerhead  205  which is described in my above co-pending application. A valve  210  controls water flow from port  145  to branches  148  and  149 , and to an optional additional showerhead  215 . In lieu of branches  148  and  149  a single pipe can be used. 
     First Embodiment 
     Operation 
     FIGS.  1  and  2   
     The installation of head assembly  100  on pipe  105  is accomplished in the following steps:
     (1) Collar  135  is slid over pipe  105  as shown with threads  140  facing toward the intended position of assembly  100 .   (2) The distal end of nut  110  is positioned at the end of pipe  105  so that threads  130  on supply pipe  105  will meet and mate with threads  115  in nut  110 .   (3) Nut  110  is screwed onto pipe  105  until tight. A thread sealant, such as PTFE (polytetrafluoroethylene) tape (not shown), can be used to ensure a leak-proof seal, if desired. Torque from a wrench (not shown) can be applied to facets  124  to tighten nut  110  on pipe  105 .   (4) Head assembly  100  is held at its desired orientation while being moved toward the proximal end of nut  110 . As wall portion  126  slidably enters inner wall  160 , O-ring  125  is compressed against wall  160 , forming a water-tight joint.   (5) Assembly  100  is rotated about the axis of port  145  until the desired orientation is reached. Then assembly  100  is urged toward nut  110 , engaging the teeth or keys of spline portions  120  and  155 . The spline teeth are closely spaced so that a slight misalignment due to interference between mating teeth will pass unnoticed.   (6) Collar  135  is slid toward assembly  100  and threads  140  and  150  are engaged and screwed together until shoulder  142  of collar  135  presses tightly against shoulder  122  of nut  110 .   

     At this point, assembly  100  is securely and non-rotatably affixed to pipe  105 . This completes the installation of assembly  100  on pipe  105 . 
       FIG. 2  shows showerhead  100  securely and non-rotatably mounted on supply pipe  105 . After installation, properly tightened collar  130  conceals nut  110  and the remaining internal components of the coupling. Due to the two sets of mating splines, assembly  100  will not be able to rotate on pipe  105 , yet the coupling or union will be water-tight, secure, and have an attractive, clean look. 
     SUMMARY, RAMIFICATIONS, AND SCOPE 
     The embodiment and variations described and shown of my improved showerhead connector ensure that an installed showerhead will remain in a desired orientation. A collar is first slid onto the supply pipe. Then a nut is screwed onto the supply pipe, whereafter the showerhead assembly is mounted onto the nut. Mating spline sections on the nut and within a port leading into the showerhead assembly permit rotational alignment during installation, yet when engaged prevent subsequent misalignment. An O-ring seal permits alignment, then provides a long-lasting water seal. When screwed onto the assembly, the collar secures the showerhead assembly to the nut. The collar can be tightened by hand, thereby preventing unsightly wrench marks on the collar, and concealing any marks on the nut. 
     While the above description contains many specificities, these should not be considered limiting but merely exemplary. Many variations and ramifications are possible. 
     Instead of being round, the exterior shape of the collar can be square, hexagonal, octagonal, or another shape. Instead of triangular spline teeth, square, rectangular, or semicircular teeth can be used. Instead of female threads on the collar and male threads on the showerhead assembly, the genders of the threads can be reversed. 
     Instead of a large open orifice leading from the supply pipe through to the showerhead assembly, a flow restrictor can be inserted. 
     Instead of female threads on the nut, male threads can be used to mate with female threads on a supply pipe. 
     Instead of a single O-ring seal, two or more such seals can be used. 
     A smooth, round surface can be used in place of facets for a wrench. In this case, pliers or a pipe wrench can be used to tighten the nut onto the supply pipe. 
     Instead of the sizes described, all elements of the design can be larger or smaller. 
     Instead of being mounted on a fixed supply pipe, the showerhead can be mounted on a handle at the end of a water feed hose. 
     The number of spline ribs can be smaller or larger and the shape of the ribs can vary. Instead of having a full set of teeth or ribs on both splines, one spline can have a full set of teeth while the other spline has as few as one tooth. If a single tooth is used, it can be replaced by a pin inserted in the nut at a location that would otherwise be occupied by a tooth. 
     Instead of being used to couple a supply pipe with the flippable showerhead with two supporting arms as shown, the showerhead can be a simple showerhead with a single supply pipe. The union can be used to couple other fluid conduits, such as pipes, spigots, hoses, and the like. 
     While the present system employs elements which are well known to those skilled in the arts of showerhead and fluid coupling design, it combines these elements in a novel way which produces one or more new results not heretofore discovered. Accordingly the scope of this invention should be determined, not by the embodiments illustrated, but by the appended claims and their legal equivalents.