Abstract:
A ball valve has a ball with resilient, opposed facing spaced-apart locking arms which engage a stem having outwardly projecting flanges to allow the stem to be inserted externally into the valve body and locked to the opposed locking arms of the ball. In one embodiment, the stem and ball include an interengaging keyway and correspondingly shaped rib for positive coupling of the ball to the stem.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of copending U.S. application Ser. No. 11/058,015, filed Feb. 15, 2005, entitled B ALL  V ALVE  W ITH  S NAP -I N  S TEM,  by Robert B. Gruener, Sr., the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to quarter-turn ball valves with an improved coupling between the ball and stem.  
         [0003]     Typical ball valves have a housing which includes an axially extending fluid communication path and a ball receiving chamber into which a ball element of the valve is inserted. The valve body also includes an opening extending orthogonally to the flow path for receiving a stem which typically includes a locking flange, such that the stem can be inserted through the stem aperture from the ball valve chamber and the ball subsequently loaded into the chamber with interlocking tongue and groove members for coupling the stem and ball. Some ball valve proposals allow the stem to be inserted from the outside of the valve body. Such construction requires a locking flange within the valve body and/or a retainer on the stem to retain the stem in locked position with respect to the valve body. Both of these types of systems are either somewhat difficult to assemble and/or result in more complicated structures for manufacturing. Thus, there exists a need for a ball valve which is both economical to manufacture and which is easy to assemble.  
       SUMMARY OF THE INVENTION  
       [0004]     The ball valve of the present invention satisfies this need by providing a ball valve having a ball with opposed spaced-apart locking arms which engage a stem having outwardly projecting flanges to allow the stem to be inserted externally into the valve body and locked to the opposed locking arms of the ball. In a preferred embodiment, the stem includes a tapered locking groove or keyway into which a mating tapered rib on the ball extends to positively lock the stem and ball together.  
         [0005]     In another embodiment of the invention, the valve stem includes a breakaway groove on a side of the stem distal from the ball such that, if the ball becomes frozen in position, the valve stem will shear at a location outside and above the stem seals if an excessive force is used to attempt to open the valve. This assures that an effort to open a frozen valve will not result in a broken valve which will leak.  
         [0006]     In yet another embodiment, the retainer carrier for the ball includes arcuate slots for receiving projections of a spanner wrench which is integrally formed on the valve handle. In this embodiment, the underside of the valve handle includes a pair of outwardly projecting tabs which are spaced and sized to interfit with the arcuate slots of the threaded retainer carrier such that, if ball, stem, or seal replacement becomes necessary, the valve handle itself can serve as a removal tool for the retainer carrier such that the valve can be disassembled without the need for special or additional tools. In the most preferred embodiment of the invention, the ball valve assembly includes both the interlocking stem feature and one or more of the breakaway stems and the integral handle tool features.  
         [0007]     These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a perspective view of the ball valve of the present invention;  
         [0009]      FIG. 2  is an enlarged exploded perspective view of the ball valve of the present invention;  
         [0010]      FIG. 3  is a greatly enlarged assembled vertical cross-sectional view of the ball valve of  FIGS. 1 and 2 ;  
         [0011]      FIG. 4A  is a greatly enlarged fragmentary cross-sectional of the area IV of  FIG. 3  illustrating the snap-locking feature of the ball and stem during insertion of the stem;  
         [0012]      FIG. 4B  is the structure shown in  FIG. 4A  after the stem has snap-locked into the ball;  
         [0013]      FIG. 5  is an enlarged perspective view of the ball;  
         [0014]      FIG. 6  is an enlarged perspective view of the valve stem;  
         [0015]      FIG. 7  is an exploded view of the valve handle and carrier, illustrating the interconnecting elements when the handle is being used as a disassembly tool;  
         [0016]      FIG. 8  is a bottom view of the handle and an end view of the ball retainer carrier;  
         [0017]      FIG. 9  is an enlarged side elevational view, partly in cross section, showing the interrelationship of the retainer carrier and valve handle used as a tool to remove and/or install the retaining ring from the valve body;  
         [0018]      FIG. 10  is an exploded perspective view of an alternative embodiment of the valve body, valve stem, and valve ball;  
         [0019]      FIG. 11  is an enlarged end elevational view of the valve ball;  
         [0020]      FIG. 12  is an enlarged end elevational view of the valve stem and valve ball, showing their interlocking relationship; and  
         [0021]      FIG. 13  is an enlarged fragmentary cross-sectional view of the valve stem and valve ball. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]     Referring initially to  FIGS. 1-3 , there is shown a valve  10  embodying a first embodiment of the present invention. The valve includes a valve body  20  having a central axially extending bore  22  providing a fluid flow path through the valve body, a central ball-receiving chamber  24  (as best seen in  FIG. 3 ), and a stem-receiving bore  26  communicating with chamber  24 . Chamber  24  is internally threaded at end  23  for receiving a threaded retainer carrier  70 , which also includes a cylindrical axially extending bore  71  aligned with valve bore  22 . Body  20  includes a quarter-turn limiting handle mounting boss  28  which includes an arcuate slot  29  formed therein which cooperates with a projecting tab  94  on handle  90  for limiting the range of motion of the ball valve to 90° or a quarter turn in a controlled manner. Valve body  20  has opposed ends  25  and  27  which are externally threaded for receiving union nuts as described below.  
         [0023]     The ball chamber  24  receives a pair of ball seat seals  12  and  14 , as seen in  FIGS. 2 and 3 , and valve ball  40  which includes a bore  42  having a diameter substantially the same as the diameter of bore  22  of valve body  20 . The ball and remaining valve elements are injection molded of a suitable polymeric material, such as PVC, polypropylene, CPVC, nylon, or any injection molding material, including metal (MIM). The ball  40 , as seen in detail in  FIG. 5 , is generally spherical and includes, extending from an upper end, an upwardly projecting generally rectangular rib  44  and integral arcuate inwardly curved locking arms  46  and  48  which are spaced from an upper surface  41  of ball  40  to define an open space  45 , as best seen in  FIG. 3 , allowing the deflection of the resilient arms  46  and  48  for assembly of the stem  50  therein as described below. The tips  47  and  49  of arms  46  and  48 , respectively, are spaced apart in spaced relationship to rib  44  and each includes beveled leading edge  43  to facilitate the snap insertion of the stem.  
         [0024]     The stem  50 , shown in detail in  FIG. 6 , includes a plurality of spaced-apart annular grooves  52  for receiving O-rings  53  ( FIGS. 2 and 3 ) for sealing the stem within bore  26  of the valve body  20 . Above grooves  52  is a breakaway groove  93  located axially on stem  50  distal from ball  40 . The purpose and function of groove  93  is discussed below. The lower end of stem  50  includes a rectangular slot  54  for receiving rib  44  in interlocking engagement, such that rotation of the stem  50  will rotate ball  40  between open and closed positions. Spaced from the end  51  of stem  50  are a pair of outwardly projecting tabs  55  and  57 , each with tapered leading edges  58 , such that the stem can be inserted downwardly in the direction indicated by arrow A in the fragmentary views of  FIGS. 4A and 4B  to initially engage the tapered edge  43  of the interlocking arms  46 ,  48  for insertion of the tip ends  47  and  49  of the arms into the retainer grooves  59  in stem  50 . Once the tip ends  47  and  49  of deflectable arms  46  and  48  clear tabs  55  and  57  they snap into the retainer groove  59 , interlocking the stem  50  to the ball  40 , as best seen in  FIG. 3 . Stem  50  also includes outwardly projecting annular ribs  60  ( FIGS. 3 and 6 ) which allow the handle  90  to be press-fit onto stem  50  for holding the handle  90  to the valve stem.  
         [0025]     Ball  40  is held within the valve body  20  by a retainer carrier  70  which is externally threaded at  73  to interlock with the internal threads  23  of valve body  20 . Retainer carrier  70  includes an axially extending bore  72  which aligns with bore  42  in ball  40  when the valve is in an open position, as shown in  FIG. 3 , and aligns also with bore  22  in valve body  20 . The retainer carrier includes collars  74  at opposite ends for receiving O-rings  75 ,  75 ′ and an annular groove for receiving a sealing O-ring  91  ( FIGS. 2 and 3 ). O-ring  75  extends outwardly from the face  76  of retainer  70  and engages the face  86  of a first end connector  80  ( FIG. 2 ) which is held in place by a union nut  82  internally threaded at  85  to screw onto the threaded end  25  of valve body  20 . O-ring  75 ′ seats against annular collar  21  of valve body  20 , as seen in  FIG. 3 , to seal the retainer  70  to ball chamber  24 . The threaded end  27  of valve body  20  also includes an O-ring retaining groove  78  for receiving an O-ring  79 , as shown in  FIG. 2 . A second end connector  88  has a face  89  which sealably engages O-ring  79  and is held thereto by a union nut  84  which is internally threaded at  87  to threaded end  27  of valve body  20 , thereby completing the valve body assembly. Connectors  80  and  84  are internally threaded for receiving externally threaded pipe fittings. In some embodiments, they may not be threaded to allow polymeric pipes to be adhesively bonded to the valve  10 .  
         [0026]     The valve handle  90  includes a central, downwardly extending aperture  92  through which the upper end of valve stem  50  extends in press-fit engagement to secure the valve to the stem. The interfit allows handle  90  to be removed for use as a tool as discussed below. The handle includes a downwardly extending tab  94  which rides within slot  29  of valve body  20  to limit the motion of the ball to within 90° between fully open and fully closed position as the tab rides within the arcuate slot  29 . The valve handle also includes a pair of downwardly projecting spaced-apart tabs  96  and  98  extending from the underside of the handle for serving as a spanner wrench, as described in detail below with references to  FIGS. 7, 8 , and  9 .  
         [0027]     One unique feature of the valve assembly  10  of the present invention is the provision of the breakaway groove  93  in valve stem  50 . In the event the ball becomes stuck due to the entry of foreign material or the like within the valve body, efforts to open or close the valve could, without the addition of the breakaway groove, result in the over torquing of valve stem  50  which could fracture the valve stem or even the valve body, resulting in a leaking and broken valve. In order to prevent such an occurrence, the breakaway groove  93  is designed to shear the valve stem before any breakage of any sealed areas of the valve body or valve stem area can occur. The breakaway groove  93  is positioned above the O-ring seals  53 , as seen in  FIG. 2 , at an end of valve stem  50  distal from ball  40 . Over torquing of the valve handle  90  to free a stuck valve will, before the fracture of internal parts of the valve or the valve body itself occur, shear the valve stem at point  93 , which allows the valve body to remain sealed against fluid leakage. The depth and height of the breakaway groove depends upon the material and size of the ball valve. In one example for a 1″ diameter ball valve  40  where the outer diameter of the valve stem is 0.64″, the depth of the valve breakaway groove was 0.095″ with a height of 0.08″ to allow a breakaway torque of approximately 60 inch pounds for a PVC material valve assembly. As the polymeric material is changed for the valve body or the size of the valve assembly, including the ball and stem, is changed, the specific dimensions of the breakaway groove may be changed to provide an appropriate shear torque which protects the sealed integrity of the valve assembly.  
         [0028]     Referring now to  FIGS. 7, 8  and  9 , an end view of the valve body  20  is shown in  FIG. 8  in which the retainer carrier  70  is shown and includes angularly spaced-apart arcuate slots  77  which are shaped to receive the downwardly projecting tabs  96  and  98  of handle  90 , as seen in  FIG. 9 , such that the handle, once removed from the valve body, can be used to rotate the retainer carrier  70  from the valve body, as illustrated in  FIG. 9 , for disassembly should an O-ring seal need to be replaced or should the ball  40  become worn and need replacement.  
         [0029]     Assembly of the ball valve  10  is provided by first inserting the ball seal seat  14  in the valve body, after which ball  40  is inserted and held in place with the rib  44  pointing upwardly and aligned with the axial bore  26 . Next, valve stem  50  with O-rings  53  installed thereon is inserted in the valve body and pushed downwardly, as indicated by arrow A in  FIG. 4A , with the leading tapered edges  58  of the stem tabs  55  and  57  engaging tapered edges  43  of the resilient locking arms  46  and  48  to deflect the arms downwardly into the open space  45  sufficiently to allow the tabs  55  and  57  to clear the tips  47  and  49  of arms  46  and  48 . This allows the stems to snap into locking groove  59 , thereby interlocking the stem to the ball, such that the ball can be rotated between a fully open position ( FIG. 3 ) and various closed positions, including a fully closed position in which the ball is rotated 90° to the position shown in  FIG. 3 , thereby effectively sealing the flow path of the valve in a conventional manner. This, of course, is achieved once the valve assembly is completed and handle  90  is press-fit onto upper end  62  of the stem, such that the handle tab  94  is aligned with slot  29 . O-ring  91  is inserted within the retaining carrier  70  and seat seal  12  is then inserted within the valve body followed by threading the retaining carrier  70  with the O-ring  91 , ball seat seal  12  and O-ring  75 ′ into the valve body such that the annular surface of ball seat seal  12  engages ball  40 , as seen in  FIG. 3 , to sealably hold the ball within the ball-receiving chamber  24 . Subsequently, O-ring  75  is installed onto retaining carrier  70 , O-ring  79  is installed onto body  20  over collar  78  and end connectors  80  and  88  are held to the valve body by union nuts  82  and  84 , respectively, to complete the valve assembly  10 .  
         [0030]     If it becomes necessary to repair the valve by either replacing ball seat seals  12 ,  14  or an O-ring, such as O-ring  75 ′ or the ball  40  itself, handle  90  can be removed and tabs  96  and  98  employed once union nut  82  and connector  80  are removed to engage slots  77  in retainer carrier  70 , as illustrated in  FIGS. 7, 8 , and  9 , for disassembly of the valve. For removal of the ball, the valve is positioned in a fully closed position which aligns the generally rectangular rib  44  in an axial direction, allowing the ball to slide axially through the open end of the valve body when the retainer carrier  70  has been removed. The retainer groove  59  is sized, as is the spacing between tips  47  and  49  of arms  46  and  48 , respectively, to allow the ball to be freely removed when rib  44  is aligned with the axial port of the valve body (i.e., orthogonal to that shown in  FIG. 3 ).  
         [0031]      FIGS. 10-13  show an alternative embodiment of the valve stem and valve body, which provides a somewhat more robust interconnection between the stem and valve ball. The valve ball is identified by reference numeral  140 , the stem is identified by reference  150 , and the valve body by reference  120  in the drawings. Ball  140  and stem  150  fit within the valve body  120  in the same manner as in the previous embodiment, however, the assembly is somewhat different due to the different interconnection provided between ball  140  and stem  150 . In the embodiment shown in  FIGS. 10-13 , the ball  140  includes a bore  142  which aligns with the fluid passageway comprising the central axially extending bore  122  of valve body  120  when the valve is in an open position (i.e., ball  140  rotated 90° from the position shown in  FIG. 10 ).  
         [0032]     The construction of the ball valve, including ball  140  and valve body  120 , is substantially the same as that described in the first embodiment. The ball, however, includes an upwardly projecting, generally trapezoidal cross section rib  144  having a somewhat wider dimension at its top surface  145  as compared to the junction  143  of rib  144  with the body of ball  140 . The ball further includes a pair of inwardly projecting curved arms  146  and  148 , which are somewhat thicker and more robust than the arms  46  and  48  of ball  40  in the previous embodiment. Thus, arms  146  and  148  do not deflect, and assembly of the ball to stem  150  is not achieved by snapping the stem into the ball as the ball is installed within valve body  120 . Stem  150  includes a mating trapezoidal slot or keyway  154 , which lockably engages trapezoidal rib  144  of valve ball  140 , as seen in  FIGS. 12 and 13 , with valve stem  150  further including a pair of outwardly extending legs  156  and  158 , which extend within slots  147  and  149  under legs  146  and  148 , respectively, of valve ball  140 , as also seen in  FIGS. 12 and 13 . The valve stem includes a pair of slots  159  on opposite sides which are dimensioned to receive the arms  146  and  148 , as seen in  FIGS. 12 and 13 . Stem  150  also includes a pair of spaced annular grooves  152  for receiving O-rings  153 , which seal the valve stem  150  within the stem-receiving bore  126  of valve body  120 , as in the previous embodiment. Additionally, the stem includes a breakaway groove  151  to prevent over torquing the valve ball  140  in the event it becomes frozen in the valve body  120 . Groove  151  is sized to break at about  100  inch pounds.  
         [0033]     The ball and stem are mounted within the valve body  120  by first inserting stem  150  into stem-receiving bore  126  with the trapezoidal slot  154  aligned with the longitudinal axis of bore  122 . Ball  140  is then aligned, as shown in  FIG. 10 , with rib  144  aligned with slot  154  and longitudinally inserted through bore  122  until rib  144  aligns with the slot  154  and is centered within bore  122  under stem  150 . This can be achieved by a suitable insertion tool during assembly. The remaining elements of the completed ball assembly, as seen in  FIGS. 1 and 2  of the previous embodiment, are then assembled as before. Thus, instead of snap-locking the stem  50  within ball  40  as in the previous embodiment, ball  140  is slidably and lockably interengaged with stem  150  through the keyway slot  154  and trapezoidal rib  144  of the stem and ball, respectively, to positively interconnect the two during assembly.  
         [0034]     The ball  140  includes a circular land  141  extending from the lower surface of ball  140  that may be used for supporting ball  140  in a center position within bore  122  during assembly. The elements of the interlocking connection between ball  140  and stem  150  could, in some embodiments, be reversed. Thus, for example, the rib could be formed in the stem and the tapered slot formed in the valve ball. The materials used for the valve, including the body, stem, valve ball and remaining elements shown in  FIGS. 1 and 2 , may include PVC, CPVC, PP or Kynar® or any material used in injection molding including metal (MIM).  
         [0035]     The valve assembly of the present invention, therefore, provides a relatively inexpensively manufactured and easily assembled ball valve which is both durable, prevents accidental breakage, and allows disassembly, if necessary, utilizing the valve handle itself as a disassembly tool.  
         [0036]     It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.