Abstract:
A ball swivel of the configuration typically utilized for pool cleaners includes male and female portions featuring an interposed stopper to reduce friction and prevent the male and female portions from binding under load, while improving sealing and continuing to allow rotational and pivotal motion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/308,901, filed on Mar. 16, 2016, the contents of which are herein incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to ball swivels, and more particularly, to ball swivels used to connect a water hose to a pool cleaner. 
       BACKGROUND OF THE INVENTION 
       [0003]    Frequently, pool cleaners—and more often, suction-type pool cleaners—utilize some kind of swivel mechanism between the pool cleaner and the water hose. Various mechanisms claim to improve coiling of the hose and or influence of the hose on the random movement on the pool cleaner. One type utilizes a non-articulating linear swivel attached to the cleaner while others utilize a linear swivel within the suction line in conjunction with a ball swivel or linear swivel attached to the cleaner to try to improve performance. Some linear swivels, for positioning on cleaner or in the suction line, incorporate ball bearings to allow for free rotation and prevent binding up under load. 
         [0004]    An example of a ball swivel can be seen in U.S. Pat. No. 6,220,636, the contents of which are herein incorporated by reference in their entirety. In this patent, an improved ball swivel is described detailing the benefits a ball swivel provides for suction-type pool cleaners. A main benefit of the ball swivel, apart from dealing well with large debris passed by the pool cleaner, is the means to provide both a 360 degree rotational as well as pivoting, articulating function in a single swivel consisting of only 2 moveable parts. Further benefits of ball swivels for pool cleaners include improved transitioning between horizontal and vertical surfaces as well as relieving the drag of hoses on the pool cleaner due to water resistance. 
         [0005]    In U.S. Pat. No. 6,220,636, internal ribs are used to reduce the contact area between the male and female portions of the ball swivel, as well as to prevent smaller debris from binding up the swivel. A sealing wiper is also included to provide a better type of seal between the male and female portion of the swivel. In U.S. Pat. No. 7,464,429, the contents of which are also herein incorporated by reference in their entirety, two swivels are combined utilizing a dual ball as a means to increase the range of articulation. 
         [0006]    A common problem with all swivels is that when suction is applied via the hose, the forces acting on the swivel components will increase to eventually cause a binding effect on the swivel. The higher the suction, the more the pivotal and rotational functions of the swivel will be adversely affected—up to a point where the swivel may become totally ineffective. 
         [0007]    The binding effect due to increased suction is significantly larger on a ball swivel than on the linear swivels typically used for this type of application. This is due to the larger contact surface area between the movable parts. Also, common method available to overcome the binding effect in linear swivels is to minimize the contact surface area between the swivel components by means of a spacer typically made of a low friction material. 
         [0008]    However due to the ball swivel having a large internal contact area between the male and female parts even reducing the contact surface area by creating cavities between ribs (e.g., as described in U.S. Pat. No. 6,220,636) the pool cleaner performance is impaired due to the high degree of friction limiting the freedom of pivotal and rotational motion. 
       SUMMARY OF THE INVENTION 
       [0009]    In view of the foregoing, it is an object of the present invention to provide an improved ball swivel for a pool cleaner. According to an embodiment of the present invention, a ball swivel comprises first male and female portions and at least a first stopper. The first male portion includes a truncated ball, a male fluid passage being formed through the first male portion extending between first and second male portion openings, the first male portion opening being located on the truncated ball. The first female portion includes a socket receiving the truncated ball via a first female portion opening, a female fluid passage extending from a second female portion opening and communicating with the male fluid passage through the first male portion opening, the socket retaining the truncated ball such that the first female and male portions are capable of relative rotational motion about a longitudinal axis separating the first male and female portion openings and relative pivotal motion toward and away from the longitudinal axis. The first stopper is arranged externally to the first male and female portions delimiting relative translation movement therebetween in at least one direction along the longitudinal axis while still permitting the relative rotational motion and the relative pivotal motion. 
         [0010]    According to an aspect of the present invention, first and second stoppers engage the first female portion at respective contact points separated by a stopper axis passing through a center point of the truncated ball, the relative pivotal motion between the first male and female portions being constrained to pivoting about the stopper axis. According to another aspect of the present invention, a spacer is arranged between the first female portion and the first stopper such that the first stopper engages the first female portion through the spacer. According to an additional aspect of the present invention, the ball swivel is formed as a dual ball swivel. 
         [0011]    These and other objects, aspects and advantages of the present invention will be better appreciated in view of the drawings and following detailed description of preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a side view of a conventional ball swivel; 
           [0013]      FIG. 2  is a perspective view of the ball swivel of  FIG. 1 ; 
           [0014]      FIG. 3  is a perspective view of the ball swivel of  FIG. 1 , pivoted away from a longitudinal axis; 
           [0015]      FIG. 4  is a sectional view taken along line  4 - 4  of  FIG. 1 , with an inset detailing a relationship of components under no load; 
           [0016]      FIG. 5  is alternate detail view of the general area of the inset of  FIG. 4 , showing a relationship of components under a suction load; 
           [0017]      FIG. 6  is a side view of a ball swivel according to an embodiment of the present invention, with hidden features shown in broken lines; 
           [0018]      FIG. 7  is a perspective view of a male portion of the ball swivel of  FIG. 6 ; 
           [0019]      FIG. 8  is a perspective view of the ball swivel of  FIG. 6 ; 
           [0020]      FIG. 9  is a side view of the ball swivel of  FIG. 6 , pivoted away from a longitudinal axis, with hidden features shown in broken lines, and with insets detailing component relationships; 
           [0021]      FIG. 10  is a perspective view of a ball swivel according to another embodiment of the present invention; 
           [0022]      FIG. 11  is a side view of the ball swivel of  FIG. 10 , pivoted away from a longitudinal axis; 
           [0023]      FIG. 12  is a side view of a male portion of the ball swivel of  FIG. 10 ; 
           [0024]      FIG. 13  is an exploded perspective view of a female portion and spacer of the ball swivel of  FIG. 10 ; 
           [0025]      FIG. 14  is a sectional view of the female portion of the ball swivel of  FIG. 10 , taken along line  14 - 14  of  FIG. 13 ; 
           [0026]      FIG. 15  is a perspective view of dual ball swivel, according to a further embodiment of the present invention; 
           [0027]      FIG. 16  is a perspective view of the male portions of the dual ball swivel of  FIG. 15 ; 
           [0028]      FIG. 17  is a perspective view of dual ball swivel, according to an additional embodiment of the present invention; and 
           [0029]      FIG. 18  is a perspective view of the male portions of the dual ball swivel of  FIG. 17 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0030]    Referring in  FIG. 1 , in a conventional ball swivel  10 , a male portion  12  and female portion  14  are so as to permit rotational motion  16  about a longitudinal axis  20  of the swivel  10 , as well as pivotal motion  22  toward and away from the axis  20 . More specifically, the male portion  12  includes a truncated ball  24  that is received in a complementary socket  26  of the female portion  14 . 
         [0031]    Fluid flows through swivel via communicating male and female fluid passages  30 ,  32  of the male and female portions  12 ,  14 . The male fluid passage  30  extends between a first male portion opening  34  on the truncated ball  24  and a second male portion opening  36 . The socket  26  receives the ball  24  via a first female portion opening  40 , with the female fluid passage extending to a second female portion opening  42 . A wiper seal  44  extends toward the ball  24  around a perimeter of the first female portion opening  40 , and is intended to minimize fluid leakage by sealing the gap  46  between the ball  24  and socket  26 . 
         [0032]    With the ball swivel  10  connected to water hose and suction applied, the male and female portions are urged toward each other in the general direction of the longitudinal axis  20 , as indicated by arrows  50 . In the conventional ball swivel  10 , this results in undesirable effects. Referring to  FIG. 5 , with suction forces effectively urging the socket  26  further onto the truncated ball  24 , the socket  26  becomes misaligned and is forced into contact with the ball  24 —as is occurring in the designated area  52 . This contact creates binding that impedes or eliminates the capacity of the swivel  10  for rotational and pivotal motion  16 ,  22 . 
         [0033]    Additionally, this misalignment between the ball  24  and socket  26  also urges the wiper seal  44  away from the ball  24 . Where the internal surface of the socket  26  is formed with ribs (used to assist in the management of small debris—see, e.g.,  FIG. 14 , ribs  282 ), significant leakage can now occur past the wiper seal  44 . 
         [0034]    In subsequent ball swivel embodiments, like components are labeled with like reference numbers (e.g., socket  24 , socket  124 , socket  224  . . . ). Except as otherwise detailed, the general structure and function of the ball swivels in each subsequent embodiment is the same as in the previous; hence, previously described features and functions will not be repetitively described. 
         [0035]    Referring to  FIGS. 6-9 , according to an embodiment of the present invention, a ball swivel  110  includes a pair of stoppers  160  arranged externally to the male and female portions  112 ,  114  (the ball swivel  110  is symmetrical such that an opposite side view from  FIG. 6  would be identical thereto). The stoppers  160  delimit relative translational movement between the male and female portions  112 ,  114  toward one another along the longitudinal axis  120  while still permitting relative rotational and pivotal motions  116 ,  122 . 
         [0036]    In the depicted embodiment, the stoppers  160  are fixed to the male portion  112 ; alternately, stoppers could be fixed to the female portion. The stoppers  160  extend toward the female portion  114  from a collar  162  of the male portion  112  surrounding the second male opening  136 . Preferably, the stoppers  160  each have a rounded surface  164  at the contact points with the female portion  114 , which, as depicted, is on the socket  126  around the perimeter of the first female opening  140 . Advantageously, the stoppers are molded, or otherwise formed, integrally with the male portion (or female portion, if fixed thereto); however, stoppers could be formed separately and subsequently affixed. 
         [0037]    Advantageously, the contact points of the stoppers  160  are separated along a stopper axis  166  which passes through an internal center point  170  of the truncated ball  124 . This configuration ensures that the female portion  114  is still able to move through its full range of pivotal motion  122 , although constrained to pivot about the stopper axis  166 . In the event the male portion  112  of the ball swivel  110  is fixed to a pool cleaner, the axis of pivotal motion  122  will accordingly be fixed relative thereto—regardless of rotation of the female portion  114 . If the female portion  114  is fixed to the pool cleaner, the axis of pivotal motion  122  will be rotatable relative thereto along with the male portion  112 . 
         [0038]    By delimiting longitudinal motion, the user of the stoppers  160  prevents undesirable engagement between the ball  124  and the socket  126  and the consequent binding. Additionally, by preserving the proper alignment between the ball  124  and socket  126 , proper sealing with the wiper seal  144  under suction load is ensured—as can be seen even in the extremes of pivotal motion  122  detailed in the insets of  FIG. 9 . 
         [0039]    Fixing the stoppers  160  as shown in the depicted embodiment delimits relative translational motion of the male and female portions  112 ,  114  toward one another, as would be experienced under suction loading. Under pressure loading, the male and female portions of a ball swivel would be urged apart along the longitudinal axis (i.e., opposite the arrows  50  in  FIG. 4 ). In the case of a ball swivel to be used in an application where a pressure loading was expected, the stoppers would be positioned to delimit translation motion of the male and female portions away from one another. 
         [0040]    While undergoing rotational motion  120  under suction load, the female portion  114  bears continuously on the contact points of the stoppers  160 , making this a high wear area. Referring to  FIGS. 10-14 , in a ball swivel  210 , a spacer  272  is arranged between the stoppers  260  and the female portion  214 , minimizing or eliminating rotation-caused wear on the stoppers  260 . The spacer  272  is preferably made of a material with enhanced wear characteristics, such as a polytetrafluoroethylene-based or acetal-based material. Additionally, the spacer  272  is preferably independently removable and replaceable if worn beyond a desirable extent, preventing replacement of additional ball swivel  210  components. 
         [0041]    The female portion  214  is rotatable relative to the spacer  272 , leaving the capacity for rotational motion  216  unaffected. Preferably, the socket  226  has a collar  274  extending around the exterior thereof, an underside of which directly engages the spacer  272 . A surface  276  of the stopper  272  abutting the collar  274  is crenelated to reduce the contact area, and resulting friction, therebetween. 
         [0042]    To prevent the collar  274  from rotating with the female portion  214 , mounting recesses  280  are formed thereon which seat on the contact points of the stoppers  260 . The mounting recesses  280  still allow the spacer  272  and female portion  214  a full range of pivotal motion  222  about the stopper axis  266 , but prevent spacer  272  rotation. 
         [0043]    The preceding features can also be used with dual swivels, similar to that disclosed in U.S. Pat. No. 7,464,429. Referring to  FIGS. 15 and 16 , the ball swivel  310  features two sets of male and female portions  312 A/B,  314 A/B and associated components, including stoppers  360 A/B and spacers  372 A/B, that function substantially as described above, except the serial combination of the sets allows for a higher degree of articulation across the entire ball swivel  310 . 
         [0044]    In the depicted embodiments, the two male portions  312 A/B are fixed directly at the respective second openings of their truncated balls  324 A/B. The stoppers  360 A/B extend away from a common collar  362  around the junction therebetween. In the ball swivel  310 , the stoppers  360 A are radially offset from the stoppers  360 B about the longitudinal axis  320 . Alternately, in a ball swivel  410 , the stoppers  460 A are aligned with the stoppers  460 B in the direction of the longitudinal axis  420 . 
         [0045]    From the foregoing, it will be appreciated that the ball swivels of the present invention advantageously prevent binding and leakage under load, while still permitting rotational and pivotal movement. However, the foregoing embodiments are provided for exemplary and illustrative purposes; the present invention is not necessarily limited thereto. Rather, those skilled in the art will appreciated that various modifications, and as well as adaptations to particular circumstances, will fall within the scope of the invention herein shown and described, and of the claims appended hereto.