Abstract:
An improved docking assembly for faucets having a pull-down sprayhead extendable from a spout. The docking assembly generally comprises a receptacle fitted into the spout which is formed with chamfered interior walls. A spring-loaded flexible collet is contained within the receptacle with a degree of sliding freedom for spring-biased travel along the chamfered interior walls of the receptacle, from a first position that allows generous radial expansion of the collet to a second position in which radial expansion is restricted. A quick-connect fitting attached to the pull-down sprayhead moves the collet into its first position allowing radial expansion of the collet. Removal of the quick-connect fitting moves the collet to its second position which restricts radial expansion, inhibiting said removal. Consequently, the pulldown sprayhead may be docked to the spout with considerably less insertion force than the opposite removal force needed to undock the pulldown sprayhead from the spout.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to faucet sprayheads, and more particularly to a pull-down sprayhead docking mechanism for kitchen faucets that provides significantly less force to dock than to undock, and a longer operational lifetime. 
         [0003]    2. Description of the Background 
         [0004]    Faucets, especially kitchen faucets, are commercially available in numerous designs and configurations. Many are equipped with pull-out spray heads that enable more flexible cleaning. There are a variety of docking mechanisms which facilitate removal and return of the spray head from the faucet. These include twist-and-lock docking mechanisms, compression-fit or detent-lock docking mechanisms, and magnetic docking mechanisms. Design goals for such docking mechanisms include ease of docking, secure retention of the sprayhead when docked, ease of undocking, and consistent operation without degradation of the foregoing qualities over a long operational lifetime. 
         [0005]    An example of a detent-lock mechanism is U.S. Pat. No. 6,845,526 to Malek et al. issued Jan. 25, 2005, which shows a pullout spray head with detent-fit docking collar with enhanced retaining force. The docking collar has an annular wall with a plurality of U-shaped slots which define a plurality of cantilevered snap fingers that fit into grooves in the connecting shaft when the spray head is docked. 
         [0006]    Many mechanical docking designs on the market today rely on crush ribs to provide the necessary sprayhead retention. A form of detent-lock, these crush ribs about the base of the sprayhead or inside the faucet head deform during insertion to facilitate engagement there between. Unfortunately after several cycles the crush rib material abrades and retention decreases. 
         [0007]    U.S. Pat. No. 6,619,567 to Ouyoung issued Sep. 16, 2003 shows a flexible water tap with pull-out sprayhead that uses a friction-fit dock (FIG. 8). 
         [0008]    U.S. Pat. No. 7,699,241 to Benstead issued Apr. 20, 2010 shows a docking collar for a pull-out spray head. This docking collar includes a spring ring. 
         [0009]    U.S. Pat. No. 7,909,061 to Nelson issued Mar. 22, 2011 shows a magnetic coupling for releasably coupling the faucet head to the faucet body. 
         [0010]    Of the foregoing and others, only the magnetic couplings provide a differential docking force, vis-à-vis a uniform attractive force whether the sprayhead is being docked or undocked. 
         [0011]    Magnets, however, are expensive. A purely mechanical docking system would be preferable, but in this context there are no known efforts to provide a differential docking force, requiring less force to dock than to undock. Moreover, conventional crush-rib type designs wear out and lose their retention ability. What is needed is a mechanical docking system that allows for the retention geometry to flex in order to reduce wear and tear, thereby prolonging the operational lifetime. 
         [0012]    The present invention provides a purely mechanical docking system that requires significantly less force to dock than to undock, keeps the pull-down sprayhead securely in place when docked, and maintains registry of the internal components so that the spray head dock will never sag or degrade. Moreover, the retention geometry eliminates wear and tear of components resulting in a longer operational lifetime without any performance degradation. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention provides improved docking assembly for a faucet including a pull-down/pull-out sprayhead extendable from a spout. The docking assembly generally comprises a receptacle fitted into a distal spout aperture of the faucet spout. The receptacle is formed as a generally annular member having chamfered interior walls. In addition, a spring-loaded flexible collet is slidably contained within the receptacle and has a degree of freedom for spring-biased travel along the chamfered interior walls of the receptacle, from a first position that allows limited radial expansion of the collet to a second position in which radial expansion of said collet is more restricted. A quick-connect fitting is attached to the pull-down sprayhead for insertion and removal into/from the collet. Upon docking of the sprayhead, insertion of the quick-connect fitting moves the collet into its first position allowing radial expansion of said collet to accommodate the quick-connect fitting, facilitating insertion. After docking of the sprayhead, a spring bias moves the collet to its second position which restricts radial expansion of the collet, discouraging extraction of the quick-connect fitting and inhibit said removal. In effect, the pulldown sprayhead may be docked to the spout with considerably less insertion force than the opposite removal force needed to undock the pulldown sprayhead from the spout. This makes docking more convenient, increases security of the docked sprayhead, and prevents inadvertent undocking, which improves usability and helps to avoid inadvertent breakage. 
         [0014]    In addition, the sprayhead according to the present invention allows for the retention geometry to flex which reduces wear allowing for prolonged use with no noticeable degradation in either insertion force or removal force. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which: 
           [0016]      FIG. 1  is a composite cross-section of a faucet with pull-down sprayhead and docking system in accordance with the present invention, including an enlarged inset (right) of the sprayhead dock. 
           [0017]      FIG. 2  is a perspective view of the internal waterway of the pull-down sprayhead of  FIG. 1 . 
           [0018]      FIG. 3  is a side view of the internal waterway of  FIG. 2 . 
           [0019]      FIG. 4  is a perspective view of the cap of the pull-down sprayhead of  FIG. 1 . 
           [0020]      FIG. 5  is a side view of the cap of  FIG. 4 . 
           [0021]      FIG. 6  is a perspective exploded view of the primary components of the docking system in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
         [0023]    Referring now to  FIG. 1  there is shown a cross-section of a faucet  10  configured with pull-down sprayhead  14  with docking system in accordance with the present invention. Faucet  10  includes a spout  12  having an internal conduit opening to an aperture, and sprayhead  14  here shown inserted in the spout  12 . The sprayhead  14  is enclosed in a housing  142  having opposing (inlet and outlet) apertures. An internal waterway  15  is mounted in the housing  142  of sprayhead  14  in a known manner to support the internal valves and other components of the sprayhead  14 , and the internal waterway  15  here extends to an annular basket  151  that is fixedly secured to the inlet aperture of the spray head  14 . 
         [0024]      FIG. 2  is a perspective view of the internal waterway  15 , and  FIG. 3  is a side view. The internal waterway  15  may be a molded plastic component, and communicates water from the spout  12  through the sprayhead  14  to a spray face which, in the illustrated embodiment, holds both aerate and spray holes. Though incidental to the present invention, a horizontally mounted poppet valve mounted on the waterway  15  is actuated by an external pivoting lever (see  FIG. 1 ) to divert water between aerate and spray modes. Water is conducted along the central axis of the waterway  15  toward the spray face, and is selectively diverted by the valve to one of two exits. A first exit allows water to escape a ring shaped chamber at the base of the sprayhead  14  through multiple pinhole outlets forming a spray jet. A second exit allows water to escape a lower central chamber at the base having a single aerating exit discharging a single water stream. The lever diverts water between the first and second outlets and thus between aerate and spray modes. One skilled in the art will understand that the selective aerate and spray modes is an optional feature and incidental to docking the sprayhead  14  to the spout  12 , and so the entire lower extent of the internal waterway  15  may take various forms as a matter of design choice. 
         [0025]    With reference to  FIG. 1 , an annular basket  151  at the top end of the internal waterway  15  that is fixedly secured to the inlet aperture of the spray head  14 . The basket  151  is an annular open ended form integrally molded and in fluid communication with the lumen  157  of the waterway  15  and includes a conventional hose coupling  162  within the interior of basket  151 . The intersection of basket  151  and lumen  157  is preferably reinforced by flanges  155  or the like. The cylindrical outer wall of basket  151  is defined by a circular flange  153  which is notched for indexed seating in the housing  142  of sprayhead  14 . 
         [0026]      FIG. 4  is a perspective view of the cap  164 , and  FIG. 5  is a side view of the cap. The cap  164  may likewise be a molded plastic component and has a base section  166  that is received within the basket  151 . The cap extends upward from the base section past a circular flange  163  at its midsection to a male quick-connect fitting  167  at a distal end that extends outward, from the sprayhead  14  (see.  FIG. 1 ). The base section  166  is defined by two annular grooves  168 ,  179 . An upper groove  168  seats an O-ring that seals the cap within the basket  151  The base section  166  is exteriorly threaded up to the lower groove  179  to facilitate screw-insertion into basket  151 . The lower groove  179  serves as an index at the minor diameter of the threads to facilitate accurate positioning of the base section  166  and easier manufacturing. Quick-connect fitting  167  has a preferably rounded annular protrusion at it distal end that is received into or docks within a receptacle  18  inserted into the spout  12  of the faucet. 
         [0027]    Referring back to  FIG. 1 , the receptacle  18  is fixedly mounted in the aperture of the distal end of the spout  12 . The quick-connect fitting  167  of internal cap  164  in the spray head  14  is removably received within the receptacle  18  in the spout  12  to facilitate manual extraction and/or docking of the spray head  14  in the spout  12 . 
         [0028]    The internal waterway  15  is mounted inside the housing  142  of sprayhead  14 , trapped therein by the circular flange  153  of basket  151  bearing underneath a lip at the inlet end of the sprayhead housing  142 , and trapped at the outlet end by the sprayface which is secured at the outlet aperture of the sprayhead housing  142 . 
         [0029]    Basket  151  seats the hose coupling  162  of waterway  15 . If desired, hose coupling  162  and basket  151  may be formed as a unitary component. The annular cap  164  wields quick-connect fitting  167  for mating with the receptacle  18  in the spout  12  to facilitate manual extraction and/or docking of the spray head  14  in the spout  12 . The annular cap  164  surrounds the hose  17  and caps the annular basket  151   
         [0030]    The hose  17  travels down to the hose coupling  162  and is outwardly sealed to the annular basket  151  by a balljoint  190  which is crimped to the hose  17 . The balljoint  190  gives the hose  17  a limited degree of translation at the junction with hose coupling  162 . The balljoint  190  has an enlarged fluted upper end  199  tapering to an annular midsection  197  and continuing to a bulbous distal end  198 . The bulbous lower distal end  198  of the balljoint  190  is pressed against an O-ring  169  which is in turn seated atop a threaded adapter  175 . The threaded adapter  175  seats atop the hose coupling  162  inside the annular cap  164 . The bulbous lower distal end  198  of the balljoint  190  is held captive within the cap  164 , sandwiched against O-ring  169  by a collar  174  held captive inside an inward lip of quick-connect fitting  167 . A spacer  172 , preferably an acetal spacer such as formed by Delrin® acetal resin adds compression to increase the compression on the O-ring  169 . The O-ring  169  seals the bulbous lower distal end of balljoint  190 , and yet this configuration gives the balljoint  190  and hose  17  a limited degree of flex and translation at the junction with the hose coupling  162 . The hose  17  continues upward through the spout  12  to the water supply, and channels the water downward through the stem of the hose coupling  162  to an output which may include a volume control valve and/or spray/aerate mode selector assembly as described above. 
         [0031]    In addition to the foregoing, several additional components are needed to implement the docking system in accordance with the present invention including receptacle  18 , and a collet  184 , coil spring  186  and sleeve  188 .  FIG. 6  is a perspective exploded view of these components (receptacle  18 , and a collet  184 , coil spring  186  and sleeve  188 ) as in  FIG. 1 . 
         [0032]    The receptacle  18  inside the spout  12  aperture comprises an annular member with an outwardly extending bottom flange and sidewalls circumscribing an internal space within which a plastically deformable or resilient collet  184  is seated. It should be observed that the term “annular” as used herein is not limited to condition of a complete or 360 degree ring and the present invention can be satisfactorily practiced where the elements described herein trace only a portion of the annular form or other forms which are in included within the meaning of the term. The receptacle  18  completely covers the lower spout  12  aperture (and if necessary, may be surrounded by an optional shim  182  brazed into the lower spout  12  aperture). In the illustrated embodiment, receptacle  18  is threaded into adapter  182 , and adapter  182  is brazed into the spout  12  aperture. 
         [0033]    The collet  184  is itself a resilient, preferably annular member having a preferably contiguous circular upper member  187  with a plurality of curvilinear spring fingers  189  extending downwardly there from. The spring fingers  189  initially taper inward to a constricted midsection and then taper outward again toward their distal ends. The collet  184  is capable of a limited extent of up/down travel within the receptacle  18  with the downward travel limited by seating of its upper member  187  against an internal ridge inside receptacle  18 . The collet  184  is biased into its downward position by a coil spring  186  which encircles a sleeve  188  surrounding the hose  17 . One end of coil spring  186  abuts the upper lip of collet  184  while the other end of spring  186  abuts sleeve  188 . The sleeve  188  has no direct interaction with the balljoint  190  but serves to keep the coil spring  186  captive in receptacle  18  and may be sonic-welded to the upper end of the receptacle  18  for this purpose. Upward travel of the collet  184  within the receptacle  18  is limited by the maximum compressive bias of the coil spring  186 . 
         [0034]    Importantly, the inner wall of receptacle  18  is sized in its midsection so that when the collet  184  is in its upward position, significant elastic deformation of the fingers  189  is permitted before the distal ends of the fingers engage the inner wall which serves to supplement the fingers own resilience such that further deformation is inhibited. However, the inner wall of the receptacle is chamfered inwardly toward a restricted lower end having a smaller size (e.g. diameter if a circular receptacle is assumed) such that little or no plastic deformation of the spring fingers  189  alone is permitted before the distal ends of the fingers engage the inner wall of the receptacle making further deformation considerable more difficult (i.e. requiring more force). When the quick connect fitting  167  is inserted inside the receptacle  18  it biases the collet  184  upward against coil spring  186  positioning the fingers  189  within the larger midsection of the receptacle which allows more room for expansion of the fingers  189  within the receptacle, thereby facilitating a looser fit of the quick connect fitting  167  inside the collet  184 . Once the fitting  167  is inserted the spring bias returns the collet (with the fitting engaged) to the lower position such that deformation of the fingers is inhibited by engagement with the inner wall of the receptacle and the force needed to disengage the fitting  167  from the collet and remove the sprayhead is increased over the engagement/insertion force. 
         [0035]    The present invention may be incorporated in a variety of sprayheads having different features, and the configuration of the internal waterway  15  may vary somewhat as a result. 
         [0036]    As mentioned above, the receptacle  18  has tubular walls that circumscribe an internal space, and the inner walls of the receptacle  18  are stepped/chamfered from top to bottom to govern the motion of spring loaded collet  184 . Specifically, the inner walls of the receptacle  18  are stepped/chamfered to define a cylindrical section with a first diameter R 1  (see  FIG. 1  inset), then stepped to a second smaller diameter R 2 , and then chamfered smoothly to a lip of smaller diameter R 3  and aperture at the bottom. 
         [0037]    Collet  184  may be molded of any resilient plastic capable of elastic deformation, defining the upper member  187  with plurality of curvilinear spring fingers  189  extending downwardly therefrom. The spring fingers  189  collectively follow a surface of revolution having a first diameter r 1 , then inwardly tapered to a second smaller diameter r 2 , and then outwardly tapered to a larger diameter r 3  and opening at the bottom. The collet  184  is capable of a limited amount of up/down travel within receptacle  18 ; travel of the collet being upwardly limited by the maximum compression of spring  186  and downwardly limited by the upper member  187  of collet  184  engaging the step of receptacle  18 . The spring  186  biases the collet in the downward or lower position. 
         [0038]    The constricted midsection of the collet  184  engages or chokes on the quick-connect fitting  167  as the fitting passes into or out of the collet and thereby imparts both insertion force and retention force thereto. Given the travel of collet  184  within receptacle  18 , the distal ends of the spring fingers  189  of collet  184  ride against the inner walls of receptacle  18 . When the resilient collet  184  is biased into its lower position the chamfered inner wall of receptacle  18  at diameter R 3  leaves less room for expansion, and yet when pushed into its upper position the chamfered inner wall of receptacle  18  at diameter R 2  leaves more room for expansion of collet  184 . Preferably, an air gap exists between R 2  and the distal ends of the fingers r 3  when the collet is in the upper position. When the quick-connect fitting passes through the constriction r 2  of the collet the fingers deflect outward reducing the air gap potentially to the point that the distal ends engage the wall surface and inhibit further deflection. When the quick-connect fitting is past the constriction r 2  of the collect, the fingers return to or toward their undeflected condition restoring, at least partially, the air gap. When the collet returns to the lower position under force of the biasing coil spring  186  the air gap is again diminished. This effectively accomplishes a differential insertion/extraction force, requiring less insertion force and more extraction force for ease of insertion and secure retention. 
         [0039]    In operation, when the quick-connect fitting  167  nipple is inserted inside the receptacle  18  it biases the collet  184  upward against coil spring  186  which gives more room for expansion, thereby facilitating a looser fit of the quick connect  167  inside the receptacle  18 . Conversely, when the quick-connect fitting  167  nipple is pulled outward from the receptacle  18  the collet  184  returns to the lower position which gives less room for expansion, thereby increasing the withdrawal force needed to remove the sprayhead  14 . In the context of a pulldown sprayhead this requires significantly less force to dock than to undock, thereby easing use yet providing a secure dock, which combine to increase the operational lifetime. Those skilled in the art will understand that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.