Abstract:
A flexible joint assembly includes a joint assembly inlet, a joint assembly outlet, and a fluid flow path between the inlet and the outlet. The fluid flow path includes a first pivot joint, a second pivot joint, and a central fluid conductor fluidly coupling the pivot joints. A method of servicing a fluid system includes transporting a fluid through a service device including the flexible joint assembly.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to the transport of fluids and, more particularly, to flexible joint assemblies, systems including flexible joint assemblies, and the service of fluid systems using flexible joint assemblies.  
         BACKGROUND  
         [0002]    When successfully transporting fluids using a fluid conduit, the fluid conduit withstands the pressure differential between the interior and the exterior of the conduit at all positions along the length of the conduit. As a result, many such conduits, including the joints between unitary conduits, are made from mechanically robust but relatively stiff, inflexible materials, such as copper and galvanized steel pipes. Indeed, as the pressure differential between the interior and the exterior of a conduit increases, conduits can become increasingly stiff. This relationship between flexibility and mechanical robustness makes it relatively difficult to deliver pressurized fluids to certain locations. For example, if pressurized fluid is to be delivered to a location on a vibrating piece of equipment, to a location that changes as equipment is serviced, or to a physically confined location difficult to access with a service device, then fluid transport can be difficult and/or impossible to achieve.  
           [0003]    One example of the transport of a pressurized fluid to such a location is the transport of refrigerant into a climate control system of an automobile from a refrigerant reservoir. Climate control systems can be charged with refrigerants, such as, for example, chlorofluorocarbons, hydrochlorofluorocarbons, or hydrofluorocarbons, and can operate at pressures commonly between 60 and 800 PSI. Because these air conditioning systems are integrated into a vehicle, the location of the service ports to these systems changes depending upon, for example, the vehicle make and model, the position of the vehicle along an assembly line, or the position at which the vehicle is parked. As a result, successive engagement and disengagement with the fittings of automotive air conditioning systems by relatively inflexible conduits is often arduous and time consuming.  
         SUMMARY  
         [0004]    A flexible, fluid conducting joint assembly can withstand relatively large pressure differentials for the transport of pressurized fluids. Flexible joint assemblies can facilitate transport of pressurized fluids to a variety of locations, to physically confined locations, or to locations that shift with time.  
           [0005]    In one aspect, a flexible joint assembly for conducting a fluid includes a joint assembly inlet, a joint assembly outlet, and a fluid flow path between the inlet and the outlet. The fluid flow path includes a first pivot joint, a second pivot joint, and a central fluid conductor fluidly coupling the pivot joints. The pivot joints together provide greater than a 60° bend between the inlet and the outlet.  
           [0006]    In another aspect, a flexible joint assembly includes a joint assembly inlet, a joint assembly outlet, and a fluid flow path between the inlet and the outlet. The flow path includes a first pivot joint, a second pivot joint, and a central fluid conductor fluidly coupling the pivot joints. Each of the first pivot joint and second pivot joint includes an inner member, a receiving member dimensioned to pivotally receive at least part of the inner member, a sealing member sealing between the inner member and the receiving member, and a supporting member supporting the sealing member substantially uniformly over the entire length of the seal between the inner member and the receiving member.  
           [0007]    In another aspect, a flexible joint assembly includes a joint assembly inlet, a joint assembly outlet, and a fluid flow path between the inlet and the outlet. The fluid flow path includes a first pivot joint configured to pivot about a first pivot P 1 , a second pivot joint configured to pivot about a second pivot P 2 , and a central fluid conductor fluidly coupling the first pivot joint and the second pivot joint. Each of the first and second pivot joints include an inner member having a dimension D in a direction substantially normal to a path through the respective of the joint assembly inlet and outlet, a receiving member dimensioned to receive at least part of the inner member, and a sealing member sealing the inner member to the receiving member at a distance of less than 14% of the dimension D from the respective pivot. Each of the first pivot P 1  and the second pivot P 2  can be a pivot point.  
           [0008]    In another aspect, a flexible joint assembly includes a joint assembly inlet, a joint assembly outlet, and a fluid flow path between the inlet and the outlet. The fluid flow path includes a first pivot joint configured to pivot over a first arc about a first pivot P 1 , a second pivot joint configured to pivot over a second arc about a second pivot P 2 , and a central fluid conductor fluidly coupling the pivot joints. Each of the first and second pivot joints include a first joint member coupled to the central fluid conductor, and a second joint member coupled to one of the joint assembly inlet and the joint assembly outlet. Either the first joint member is dimensioned to pivotally receive at least part of the second joint member or the second joint member is dimensioned to pivotally receive at least part of the first joint member. The received joint member has a dimension D in a direction substantially normal to a path through the respective of the joint assembly inlet and outlet. A contact point between the receiving joint member and the central fluid conductor whereby the pivot joint is fully pivoted over the respective arc being within 75% of the dimension D distant from the respective pivot.  
           [0009]    In another aspect, a flexible joint assembly includes a first ball and socket joint, a second ball and socket joint, and a unitary central fluid conductor connecting the first ball and socket joint and the second ball and socket joint. The assembly is configured to withstand pressures between about 200 and 5000 PSI. Each of the first ball and socket joint and second ball and socket joint can include a sealing member between the ball and the socket and a supporting member contacting the sealing member substantially uniformly over the entire length of the seal between the ball and the socket.  
           [0010]    In another aspect, a method of servicing a fluid system includes connecting a service device with a service port of a fluid system and transporting a fluid pressurized to between 200 and 5000 PSI through the service device. The service device includes a flexible joint assembly including a pair of ball and socket joints connected by a fluid conductor. The fluid can be a refrigerant. The flexible joint assembly can be configured to bend through an angle of up to 90°. The fluid can be pressurized above 300 PSI. Each of the ball and socket joints can include a ball having a diameter D and pivoting about a pivot point and a retaining ring retaining the ball in the ball and socket joint. The fluid conductor can include each ball connected by a pipe member. The fluid system can be a climate control system.  
           [0011]    In another aspect, a method of servicing a fluid system includes connecting a service device with a service port of the fluid system, the service device including a flexible joint assembly, and transporting a fluid through the coupling. The flexible joint assembly includes a pair of flexible joints connected by a fluid conductor and is configured to bend through an angle greater than 60°. The flexible joint assembly can be configured to bend through an angle greater than 80°. The flexible joint assembly can be configured to bend through an angle greater than 88°. The fluid system can be a climate control system. The fluid can be a refrigerant.  
           [0012]    Each pivot joint can independently include a ball and socket joint. Each ball and socket joint can include a socket, a ball received in the socket, and a seal between the ball to the socket. Each ball and socket joint can include a compressing member axially compressing the seal between the ball and the socket. Each compressing member can include a retaining ring compressing the seal between the ball and the socket. The central fluid conductor can couple to a first ball of the first pivot joint and a second ball of the second pivot joint. The first pivot joint and second pivot joint can together provide a substantially 90° bend between the inlet and the outlet. The central fluid conductor can be unitary. The central fluid conductor can be shorter than 10 centimeters. The joint assembly inlet and the joint assembly outlet can include a fitting. Each pivot joint can independently provide greater than a 35° bend in the fluid flow path. Each pivot joint can independently provide greater than a 40° bend in the fluid flow path. Each sealing member can include an annular seal having a first surface. Each supporting member can include an annular support having a second surface configured to mate with the first surface of the annular seal thereby supporting the annular seal substantially uniformly. Each receiving member can include a first engagement surface and each supporting member can include a second engagement surface. The first engagement surface can be configured to engage the second engagement surface to maintain a fixed relative position between the receiving member and the supporting member. The first engagement surfaces can include threads dimensioned to engage with threads on the second engagement surface. Each sealing member can include an elastomeric material. Each inner member can include a ball, each receiving member can include a socket, and each sealing member can include an O-ring sealing the ball to the socket. The O-ring can have an inner diameter greater than 90% of the diameter of the ball. The receiving joint member can extend less than 35% of the dimension D beyond the first pivot joint. Each of the first pivot joint and the second pivot joint can include a second joint member dimensioned to pivotally receive at least part of the first joint member and extend less than 30% of the dimension D centrally beyond the respective pivot. Each of the first pivot P 1  and the second pivot P 2  can be a pivot point. The first joint member can be dimensioned to receive at least part of the second joint member and define a chamber in communication with the central fluid conductor. The chamber can be dimensioned to subsume an at least 115° arc about the respective pivot. The dimension D can be a diameter of the ball in a ball and socket joint.  
           [0013]    Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a view of a service system including a flexible joint assembly.  
         [0015]    [0015]FIG. 2A is a sectional view of a flexible joint assembly in a straight position.  
         [0016]    [0016]FIG. 2B is a sectional view of a socket of the flexible joint assembly of FIG. 2A.  
         [0017]    [0017]FIG. 2C is an enlarged sectional view of a portion of the flexible joint assembly of FIG. 2A.  
         [0018]    [0018]FIG. 3 is a sectional view of a flexible joint assembly in an offset position.  
         [0019]    [0019]FIG. 4 is a sectional view of a flexible joint assembly in a 90° bend position.  
         [0020]    [0020]FIG. 5 is a sectional view of a flexible joint assembly in a straight position. 
     
    
     DETAILED DESCRIPTION  
       [0021]    Referring to FIG. 1, a fluid system  20  can be serviced using a service device  30  that includes a flexible joint assembly. The fluid system can be pressurized, for example, having a fluid pressure between 20 and 5000 PSI, particularly between 40 and 4500. The pressure can be greater than 200 PSI, or less than 4000 PSI.  
         [0022]    Fluid system  20  includes a valve  28  and a service port  26  on an inlet line  24 .  
         [0023]    Service device  30  includes a fluid chamber  32  in communication with a line  34 . Fluid chamber  32  can be filled, for example, with a pressurized fluid. Line  34  terminates in a coupling  36  and includes both a valve  38  and flexible joint assembly  100  between coupling  36  and chamber  32 . Flexible joint assembly  100  provides flexibility to pressure line  34  while allowing operation with a pressurized fluid.  
         [0024]    System  20  can be serviced by aligning and engaging coupling  36  with service port  26 . The flexibility in line  34  provided by joint assembly  100  facilitates alignment and engagement of service device  30  to service port  26 . For example, if service port  26  is often found at different locations or if service port  26  moves, then assembly  100  can flex to accommodate the displacement.  
         [0025]    If service device  30  is designed to pressurize system  20 , service device  30  can be designed to charge an automotive air conditioning system and line  34  can be used to conduct refrigerant fluid from chamber  32  into system  20  when the pressure in chamber  32  is greater than the desired maximum pressure in system  20 . The operator aligns and engages fluid coupling  36  with corresponding service port  26 . This includes flexing joint assembly  100  as needed to attach coupling  36  to service port  26 . After engagement, the operator can open valves  38  and  28  to allow refrigerant fluid to charge system  20 . Once a desired amount of refrigerant fluid has been delivered to system  20 , valves  38  and  28  can be closed and coupling  36  can be disengaged from port  26 .  
         [0026]    Referring to FIG. 2A, flexible joint assembly  100  includes a fluid conductor  200 , a first ball and socket joint  300 , and a second ball and socket joint  400 . Fluid conductor  200  is of unitary construction and has a tubular central portion  240  that defines a straight longitudinal channel  210  between a first conductor end  211  terminated by a ball  217  and a second conductor end  212  terminated by a ball  218 . Channel  210  can be rotationally symmetric about the center of the channel. Balls  217 ,  218  have diameter D. Balls  217 ,  218  each form ball and socket joints  300 ,  400  in conjunction with respective sockets  317 ,  417 , sealing members  320 ,  420 , supporting members  330 ,  430 , and retaining rings  340 ,  440 . Sockets  317 ,  417  each define respective longitudinal channels  310 ,  410  that are in fluid communication with longitudinal channel  210  and can be rotationally symmetric about the center of the channel. Longitudinal channels  310 ,  410  each terminate at a respective fitting  350 ,  450 . First ball and socket joint  300  and second ball and socket joint  400  seal the juncture of channels  310 ,  410  with channel  210 , and allow for swiveling about pivot points P 1 , P 2  at the center of balls  217 ,  218 . Since first ball and socket joint  300  and second ball and socket joint  400  swivel about a respective pivot point P 1 , P 2 , the path of fluid flow through flexible joint assembly  100  is flexible and can pass through one or more geometric planes.  
         [0027]    For the sake of convenience, the structure of first ball and socket joint  300  and second ball and socket joint  400  will be discussed using the reference numbers associated with first ball and socket joint  300 .  
         [0028]    Referring to FIG. 2B, channel  310  of socket  317  extends through a fitting  350  to a socket chamber  360 . Fitting  350  can be any of a variety of end fittings suitable for connecting with a fluid system  30 , including, for example, a ¼ inch or ⅜ inch male flare fitting, a ¼ inch or a ⅜ inch female swivel fitting, a 14 mm male or female fitting, a threaded fitting, a hose barb, a SWAGELOCK fitting, a ½ inch ACME male or female swivel fitting, or a pipe fitting. Socket chamber  360  includes an interior prechamber  370  and an exterior receiving chamber  380 . Interior prechamber  370  is defined in part by an angled face  371  and an annular wall  372 . Exterior receiving chamber  380  is defined in part by an angled face  384 , a lateral face  385 , an annular wall  386 , a second lateral face  387 , and an interiorly threaded annular wall  388 . In the portion defined by annular wall  372 , prechamber  370  is generally tubular in shape and has a diameter that is slightly smaller than the diameter of ball  217  (not shown). This prevents ball  217  from sealing with angled face  371 . Interior prechamber  370  can subtend a greater than 115° conical arc defined by lines A 1 , A 2  between pivot P 1  and the junction between annular wall  372  and angled face  384 . Interior prechamber  370  can subtend, for example, a 121° conical arc of such a sphere. On the other hand, receiving chamber  380  is dimensioned to receive ball  217 , allowing ball  217  to be inserted until it contacts or nearly contacts angled face  384  when the assembly is not pressurized. Angled face  384  and ball  217  do not contact when the assembly is pressurized.  
         [0029]    Referring to FIG. 2C, ball  217  is sealed in receiving chamber  380  by sealing member  320 , supporting member  330 , and retaining ring  340 . Sealing member  320  has an outer radial surface  321 , an inner radial surface  322 , and lateral surfaces  323 ,  324 . Inner radial surface  322  is dimensioned to be at least slightly smaller in diameter than ball  217 , but large enough in diameter to seal with ball  217  outside prechamber  370 . In other words, sealing member  320  seals with ball  217  close to the pivot point P in receiving chamber  380 . It is preferred that the inner diameter of sealing member  320  be greater than 90% of the diameter of ball  217 , and more preferred greater than 95% of the diameter of ball  217 . Outer radial surface  321  seals with wall  386 . The inner diameter of sealing member  320  can be, for example, 98.6% of the diameter of ball  217 . The plane containing sealing member  320  can be less than 14% of the diameter of ball  217  away from pivot point P 1 , and more preferably less than 10%. The plane containing sealing member  320  can be, for example, 8.2% of the diameter of ball  217  away from pivot point P 1 . Supporting member  330  has an outer radial surface  331 , an inner radial surface  332 , and lateral surfaces  333 ,  334 . Inner radial surface  332  is dimensioned to be at least slightly smaller in diameter than ball  217  and is contoured to follow the surface of ball  217 . The inner diameter of supporting member  330  can be, for example, 93.8% of the diameter of ball  217 . Lateral surface  334  of supporting member  330  contacts lateral face  323  of sealing member  320  substantially completely on the circumference of ball  217 . Retaining ring  340  has a threaded outer radial surface  341 , an inner radial surface  342 , lateral surfaces  343 ,  344  and an inwardly extending pointed lip  345  with an angled face  346 . Threaded outer radial surface  341  is dimensioned to threadedly mate with interiorly threaded wall  388 . Lateral surface  344  of retaining ring  340  contacts lateral face  333  of supporting member  330  substantially completely on the circumference of ball  217 . Angled face  346  and lateral face  333  meet at a vertex  347  that follows an annular path with a diameter at least slightly larger than the diameter of ball  217 . Vertex  347  can have, for example, an inner diameter of 100.8% of the diameter of ball  217  to permit assembly. As discussed further below, angled face  346  allows central portion  240  to swivel through an arc within socket  317  by allowing increased angular displacement of central portion  240  without contacting retaining ring  340 .  
         [0030]    Referring to FIGS. 2B and 2C, when assembling ball and socket joint  300 , sealing member  320  is positioned within receiving chamber  380  such that outer surface  321  contacts wall  386  and inner surface  322  extends radially inward beyond lateral wall  385 . Retaining ring  340  slips over ball  217  over central portion  240 . Supporting member  330 , which can be a split ring, is then positioned around central portion  240  and against lateral face  333  of supporting member  330 . The user then inserts ball  217  into receiving chamber  380 . Supporting member  330  is selected and positioned such that, within receiving chamber  380 , lateral surface  334  contacts lateral wall  387  and lateral face  323  of sealing member  320 , and inner radial surface  332  contacts ball  217 . Supporting member  330  is oriented such that angled inner radial surface  332  has a relatively large contact area with ball  217 . The user then threads retaining ring  340  into threaded outer radial surface  341 , thereby applying an inward axial force to both sealing member  320  and supporting member  330 . This axial force acts to retain ball  217  within receiving chamber  380  between supporting member  330  and angled face  384 , as well as to axially compress sealing member  320  between supporting member  330  and wall  385 . Moreover, since lateral surface  334  of supporting member  330  contacts with lateral face  323  of sealing member  320  uniformly over a substantially complete circumference, sealing member  320  is substantially uniformly compressed and supported by supporting member  330 .  
         [0031]    Both the retention of ball  217  and the support and axial compression of sealing member  320  facilitate operation with fluid systems. When ball  217  is retained in receiving chamber  380  between supporting member  330  and angled face  384 , it deflects inner radial surface  332  of supporting member  330  laterally toward inner radial surface  342  of retaining ring  340  and radially compressing and sealing with sealing member  320 . Furthermore, the axial compression of sealing member  320  between supporting member  330  and wall  385  would increase the radial thickness of sealing member  320  between outer radial surface  321  and inner radial surface  322  were it not for the fact that sealing member  320  is radially compressed by ball  217  and inner radial surface  386  of body  317 . Instead, the quality of the seal formed with sealing member  320  is further increased. Moreover, since the axial compression and support provided by supporting member  330  to sealing member  320  is uniform over a substantially complete circumference, sealing member  320  can provide a uniform seal over the entirety of outer radial surface  321  and inner radial surface  322 .  
         [0032]    Referring to FIGS. 3 and 4, a flexible joint assembly  100  in various positions is illustrated.  
         [0033]    Referring in particular to FIG. 3, a flexible joint assembly  100  in an offset position allows fluid flow between sockets  317 ,  417  when they are offset. In the illustrated section, the central axes of channels  210 ,  310 , and  410  are all in a plane. Angled faces  384 ,  484  prevent balls  217 ,  218  from entering prechambers  370 ,  470  and sealing off channel  210  when the assembly is not pressurized. When pressurized, a continuous, uninterrupted fluid flow path through channels  210 ,  310  and  410  of flexible joint assembly  100  is achieved.  
         [0034]    In particular, each of fittings  350 ,  450  can be connected to a fluid flow line or a coupling or other device. A flowing fluid can enter channel  310  and proceed through prechamber  370 , make a turn of α degrees into channel  210 , pass through prechamber  470 , and make an β degree turn in the opposite direction out channel  410 . If α is equal to β, the fluid flow path is in the same direction but offset in position by an amount that is proportional to the length of fluid conductor  200  and the sine of angle α. It is preferred that the maximum of each of α and β independently be greater than 30°, greater than 40°, greater than 44°, or equal to 45°. The maximum α and β are determined, in part, by the extent that socket  317  and retaining ring  340  extend to the contact point between central portion  240  and angled face  346 . Lateral face  343  can extend, for example, less than 40% of the diameter of ball  217  centrally past the pivot point P 1  of ball  217 , less than 35% of the diameter of ball  217 , or less than 30% of the diameter of ball  217 . Lateral face  343  can extend, for example, 29% of the diameter of ball  217  centrally past the pivot point P 1  of ball  217 .  
         [0035]    Since angled faces  346 ,  446  limit the central extension of retaining rings  340 ,  440  near central portion  240 , central portion  240  can rotate through a relatively large arc within sockets  317 ,  417 . The central extension of retaining rings  340 ,  440  are thus to be taken at the contact point between central portion  240  and angled faces  346 ,  446 . In other words, angled faces  346 ,  446  allow contact between central portion  240  and angled faces  346 ,  446  to occur at relatively large angles α, β, allowing for relatively larger offsets to be achieved.  
         [0036]    Contact between central portion  240  and angled faces  346 ,  446  at the maximum α occurs approximately at junction J 1  of ball  217  and central portion  240  and junction J 2  of ball  218  and central portion  240 . This allows central portion  240  to swivel through a relatively large arc within sockets  317 ,  417 . Contact between central portion  240  and angled faces  346 ,  446  occurs at a position that less than 75% of the diameter of ball  217  distant from pivots P 1 , P 2 , less than 70%, or less than 65%, to form an assembly small in size having maximum flexibility. Alternatively, central portion  240  can be long to provide a large offset in the positions of channels  310 ,  410 . Contact between central portion  240  and angled faces  346 ,  446  can occur, for example, at a position 62.4% of the diameter of balls  217 ,  317  distant from a respective pivot P 1 , P 2 .  
         [0037]    Referring to FIG. 4, a flexible joint assembly  100  in a bent position provides a relatively large angular displacement in the direction of fluid flow between sockets  317 ,  417 . In the illustrated section, the central axes of channels  210 ,  310 , and  410  are all in a plane, and the relative positions of socket  317  and central member  240  are unchanged from FIG. 3, whereas socket  318  has pivoted as discussed below.  
         [0038]    Each of fittings  350 ,  450  can be connected to a fluid flow line or a coupling or other device. A flowing fluid can then enter channel  310  and proceed through prechamber  370 , make a turn of α degrees into channel  210 , pass through prechamber  470 , and make an β′ degree turn in the same direction out channel  410 . The net change in the angular displacement in the direction of fluid flow between sockets  317 ,  417  is equal to the sum of angles α and β′. Angle β can equal angle β′. It is preferred that the maximum sum of α and β′ be greater X than 60°, greater than 80°, and greater than 88°, or equal to 90°. It is therefore possible to achieve relatively large net angular bends in the fluid flow path through joint assembly  100 .  
         [0039]    Retaining rings  340 ,  440  are dimensioned to maximize the filly bent position of joint assembly  100 . Outer surfaces  301 ,  401  of sockets  317 ,  417  have a diameter less than 141% of the length L of central portion  240  between balls  217 ,  218 . Outer surfaces  301 ,  401  of sockets  317 ,  318  can be 137% of the length of central portion  240  between balls  217 ,  218  in diameter. This allows the sum of α and β′ to be 90° without outer surfaces  301 ,  401  contacting one another and preventing flexure of joint assembly  100 .  
         [0040]    Referring to FIG. 4, in moving from the offset to the bent position, socket  318  has pivoted through an arc that spans an angle equal to the sum of β and β′ while maintaining a continuous flow path that can operate with pressurized fluids. Alternatively, channel  310  is rotated out of the plane by 180°. Ball and socket joint  400  can be free to swivel through a greater than or equal to 60° arc, through a greater than or equal to 80° arc, through a greater than or equal to 88° arc, or through an arc that is greater than or equal to 90°.  
         [0041]    Exemplary dimensions of a flexible joint assembly  100  are as follows: central portion  240  can be 0.747 cm (0.294 inches) long between balls  217 ,  218 ; balls  217 ,  218  can be 1.27 cm (0.5 inches) in diameter; lateral surface  333  of supporting member  330  can be 0.244 cm (0.096 inches) away from pivot P 1 ; and pivots P 1  and P 2  can be 1.905 cm (0.75 inches) apart. Other exemplary dimensions can be deduced from other portions of this written description.  
         [0042]    Sealing member  320  can be an O-ring made from, for example, a molded nitrile rubber, an ethylene propylene rubber, VITON, NEOPRENE, a fluorosilicone, or a silicone elastomer or mixtures thereof. Supporting member  330  can be a split ring made from, for example, molded hard plastics such as TEFLON, HDPE, and acetal. Sockets  317 ,  318 , central member  200 , and retaining ring  340  can be made from, for example, cast, sintered, or machined copper, steel, brass, stainless steel, or hard plastics.  
         [0043]    Referring to FIG. 5, flexible joint assembly  100  includes a fluid conductor  200 , a first ball and socket joint  1300 , and a second ball and socket joint  1400 . Balls  217 ,  218  each form the respective of ball and socket joints  1300 ,  1400  in conjunction with a respective of sockets  1317 ,  1417 , sealing members  1320 ,  1420 , support members  1330 ,  1430 , and retaining rings  1340 ,  1440 . Sockets  1317 ,  1417  each define a respective channel  1310 ,  1410 . First and second ball and socket joints  1300 ,  1400  seal the juncture of channels  1310 ,  1410  with channel  210 , and allow for swiveling about respective pivot points P 1 , P 2  at the center of balls  217 ,  218 .  
         [0044]    Referring to one end of joint assembly  100 , ball  217  is sealed in socket  1317  by sealing member  1320  and supporting member  1330 . Retaining ring  1340  has a threaded inner radial surface  1342  that is dimensioned to threadedly mate with exteriorly threaded wall  1389  of socket  1317  and an inwardly extending pointed lip  1345  that extends radially inward to retain sealing member  1320  within socket  1317 . By mating retaining ring  1340  with socket  1317  at the exterior of socket  1317 , a relatively larger contact area between threaded mating surfaces can be obtained. This increases the number of threads in the contact area, and hence increases the strength of the mating and the differential pressures that can be accommodated.  
         [0045]    Although the figures all illustrate the central axes in a single plane, the sockets can naturally be swiveled out of a single plane. The support member can be two half rings with the same radii. Ball and socket joints can be swivel sockets. A valve can open automatically upon mating of the service device with a service port. The arrangement of the valve and joint assembly along the service line can be changed. The joint assembly can act as a bulkhead connection on the fluid chamber. Fluid can be pumped into the fluid system. The relative orientation of the balls and sockets can also be inverted.  
         [0046]    Other embodiments are within the scope of the following claims.