Patent Publication Number: US-2005134038-A1

Title: Fitting for fluid conveyance

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to Provisional Application 60/530,687, filed on Dec. 17, 2003, the contents of which are hereby incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD  
      The present invention relates to fluid fittings or connectors for tubing and in particular to a connector that provides a branch connection for a tube without separating the tube.  
     BACKGROUND OF THE INVENTION  
      There are many industrial applications where a relatively high pressure hydraulic system requires that branch connections be made between a tube and a component such as another fluid handling system, pump, motor, valve, switch, sensing device or the like. The fluid transfer tube may be made out of steel, aluminum, or a copper material where bonding methods in addition to brazing are used to attach the additional outlet, commonly known as a “T-fitting”. Prior art hydraulic systems have historically involved separating the tubing and then using threaded or brazed fittings to make branch connections.  
      When using a brazed connection, the tube is typically cut and a connector is positioned within the flowpath of the tube, with the tube ends being inserted into female ends of the connector. If the tubing has been pre-formed by forming a series of bends therein, the tubing ends must be properly aligned before brazing to ensure that the desired pre-formed shape is not altered as the connector is installed. Also, when installing a connector in a pre-formed tube, a section of tube must be removed and discarded to account for the increased length provided by the connector. The connector is then brazed to the tube. A second tube can be connected to a branch section of the connector. While these prior art connectors may be adequate for their intended purpose, disadvantages for particular applications exist.  
      One disadvantage of a brazed connector is that any protective coating, such as a corrosion resistance coating, or surface on the tubing and connector must be reapplied after the brazing process since the heat of the brazing process will typically remove at least a portion of this coating. The use of a brazing furnace, or other coating methods, and subsequent recoating is both expensive and time consuming. Therefore, the brazing process requires cutting the tubing twice, discarding a section of tubing, attaching the connector, aligning the tubing ends, brazing both connector ends to the tubing, and recoating the tubing and connector, by electroplating or electro-deposition or the like. Another disadvantage of prior connectors is that a reliable seal with the tube is difficult to achieve as installation steps are eliminated. What is needed, therefore, is a connector that can be connected to a tube such that the protective coating is not removed or altered. A favorable connector would require fewer steps to install, thereby reducing the amount of time and expense for the installation.  
     SUMMARY OF THE INVENTION  
      Fluid connectors are provided that eliminate the number of steps required for installation, eliminate required brazing and coating processes and the environmental impact of resulting waste streams, eliminate wasted tubing, and/or reduce the cost of installation. Since industry accepted pre-coated tube is used, the need for multiple sites for plating is eliminated. The connector can be slid onto the tube, thereby eliminating the need for cutting the tube. An aperture can be pierced into the tubing, thereby reducing the shavings and other contamination associated with cutting the tubing. The connector can be slid onto the tubing prior to installing bends, thereby permitting the connection to be formed during subsequent operations while eliminating the step of aligning the portions of a separated tube prior to brazing.  
      A fluid connector according to an exemplary embodiment has a hollow body defining a first opening, a second opening, a third opening and a main passageway. The main passageway interconnects the first and second openings and the third opening is in fluid communication with the main passageway. The first opening is also defined by a cylindrical surface that selectively extends around a conduit.  
      Another embodiment provides a coupling system for a plurality of fluid conduits that includes a first conduit and a connector. The connector includes a first end defining a first opening, a second end defining a second opening, and a main passageway extending therebetween. The first conduit is interposed through the main passageway, and a cross-section of the connector, taken normal to a main axis of the connector, defines a circular surface that extends around an outer surface of the first conduit.  
      A further embodiment provides a method of interconnecting a plurality of fluid conduits that includes inserting a main conduit through a main passageway of a connector, where the main passageway is sealed around the circumference of at least a portion of the main conduit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:  
       FIG. 1  illustrates a planar view of a fitting for fluid conveyance according to an embodiment.  
       FIG. 2  is a sectional side view of the fitting of  FIG. 1  shown with a conduit interposed therein.  
       FIG. 3  is a partial sectional view of a further embodiment of a T-fitting in accordance with the present invention.  
       FIG. 4  is a sectional view of a Y-fitting according to an alternate embodiment of the present invention.  
       FIG. 5  is sectional view of an X-fitting according to a further alternate embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to  FIGS. 1 and 2 , a fitting, coupling, or connector  20  is illustrated. Connector  20  includes a main body  22  having a main portion  24  extending from a first end  26  to a second end  28 , and defining a main passageway  30  having an axis A-A and an outer surface  34 . Main body  22  further includes a branch portion  36  extending from main portion  24  at a branch end  40  to a third end  42  and defining a branch passageway  44  and an outer surface  46 .  
      As best seen in  FIG. 2 , main portion  24  includes a generally cylindrical surface  60  defining the main passageway  30  with annular grooves  64  formed therein. Annular grooves  64 , as discussed below, accommodate seals (not shown). Branch passageway  44  is in fluid communication with main passageway  30 . An integral main conduit  70  is interposed through main passageway  30 , extending beyond first and second ends  26 ,  28 . A piercing member, or hollow screw,  76  is shown extending through an aperture  80  formed in main conduit  70 . Branch portion  36  includes a connection port  72  for connecting branch portion  36  to a second conduit (not shown). Interior threads are shown for connection port  72 , but exterior threads or other connecting mechanisms known in the art may be used to connect branch portion  36  to a second conduit.  
      An embodiment of coupling connector  20  to main conduit  70  involves inserting a main conduit  70  into main passageway  30  and then inserting a self-tapping, hollow screw  76  partially into aperture  80 . Thus provided, the interference between the branch passageway  44  and the portion of the hollow screw  76  that extends beyond an outer surface of the main conduit  70  restrains connector  20  both axially and circumferentially on the main conduit  70 , allowing the seals disposed in annular grooves  64  to prevent leakage of fluid between main passageway  30  and the main conduit  70 . The hollow screw  76  allows an internal portion of the main conduit  70  to be in fluid communication with the branch passageway  44 . An advantage of this approach is that it allows a degree of relative axial and circumferential movement between connector  20  and the main conduit  70  when desired, while eliminating the need for crimping first and second ends  26 ,  28 .  
      Another embodiment of securing connector  20  to main conduit  70  is to crimp first end  26  and/or second end  28 . This crimping can be performed in any known way, including a 4, 6 or 8-jaw crimper. This crimping secures connector  20  to main conduit  70 , thereby inhibiting relative axial and circumferential movement therebetweeen. As an example, a 4-jaw crimper would contact first end  26  adjacent branch end  40  with four separate, radially moveable, circumferentially spaced jaws. The jaws are then forced radially inward to distort first end  26 , thereby securing first end  26  onto main conduit  70 . Depending upon the amount of force used, first end  26  will begin to distort to a square shape. During this crimping process, main conduit  70  may be distorted as well, up to and including a resulting square shape, when viewed along axis A-A. This distortion of first end  26  and main conduit  70  provides some degree of resistance for relative torques about axis A-A of connector  20  and main conduit  70 . The distortion of first end  26  and main conduit  70  also limits the relative movement between connector  20  and main conduit  70  along the A-A axis as adjacent portions of first end  26  and main conduit  70  remain undistorted.  
      Crimping first end  26  about annular grooves  64  with seals disposed therein has been found to provide an adequate coupling between connector  20  and main conduit  70 , while allowing the seals to continue to perform a sealing function. Each of these approaches to coupling connector  20  to main conduit  70  and forming aperture  80  may be used with any embodiment of a connector described herein. A six-jaw crimper begins to form a hexagonal shape in first end  26  and an eight-jaw crimper begins to form an octagonal shape in first end  26  as the connector is secured to the main conduit.  
      With reference to  FIG. 3 , an alternate embodiment of connector  20  is illustrated as a connector  120 . Connector  120  includes a main body  122  having a main portion  124  extending from a first end  126  to a second end  128 , and defining a main passageway  130  having an axis B-B and an outer surface  134 . Main body  122  further includes a branch portion  136  extending from main portion  124  at a branch end  140  to a third end  142  and defining a branch passageway  144  and an outer surface  146 .  
      Main portion  124  includes a generally cylindrical surface  160  defining a portion of the main passageway  130  with annular grooves  164  formed therein. Annular grooves  164  retain seals  166  that form a seal between main portion  124  and a main conduit, first conduit, or tube,  170 . Preferably, seals  166  are o-rings. Branch passageway  144  is in fluid communication with main passageway  130 . Branch portion  136  includes a connection port  172  for connecting branch portion  136  to a second conduit (not shown). Outer surfaces  134 ,  146  have an optional coating applied thereto.  
      The first end  126  and the second end  128 , with thickness T, are illustrated in  FIG. 3  crimped onto first conduit  170  with an 8-jaw crimper. Differences between crimping connectors  20  and  120  include connector  120  may be crimped in a location that would not distort seals  166 , and connector  20  can be used in a location where a shorter distance between first end  26 ,  126  and second end  28 ,  128  is desired. This crimping operation for connector  120  is sufficient to couple first and second ends  126 ,  128  to first conduit  170  while not distorting any coating on connector  120  and main conduit  170  to the extent that the underlying material is exposed. In this manner, connector  120  may be connected to first conduit  170  while not requiring a re-coating operation. Furthermore, the crimping operation may provide an adequate seal between first and second ends  126 ,  128  and first conduit  170  to alleviate the need for seals  166 . To affect this sealing during the crimping operation, cylindrical surface  160  may be provided with a sealing layer, such as a polymer or a soft metal.  
      The crimping process may sufficiently distort first end  126 , second end  128 , and portions of the main conduit adjacent first and second ends  126 ,  128  that the eight-jaw crimper forms a generally distorted octagonal shape. An advantage of this shape is that, as mentioned earlier, it provides resistance for relative torques about axis B-B of connector  120  and main conduit  170  and limits the relative movement between connector  120  and main conduit  170  along the B-B axis. Where greater torque and axial movement resistance are desired, a four-jaw crimper may be used to form a generally distorted square shape.  
       FIG. 3  further illustrates an aperture  180  formed in main conduit  170 . Aperture  180  allows main conduit  170  to be in fluid communication with branch passageway  144 . Aperture  180  may be formed in any variety of ways, including piercing, tapping, or drilling, and may also be formed or enlarged during the installation of the second conduit. Also, aperture  180  may be any shape and size as desired, provided that aperture  180  does not extend beyond the sealing between connector  120  and main conduit  170 . Furthermore, aperture  180  may be formed after the installation and/or use of main conduit  170 , so as to provide for a system modification, or a drain or a sample location that can be readily closed.  
      Aperture  180  may be performed in the same process step as the crimping of ends  126 ,  128  to further eliminate costs and time associated with the installation of connector  120 . For installations such as a power steering pressure transducer, a small aperture  180  of about ⅛ inch in diameter may be formed, although other diameters may be formed.  
       FIG. 4  illustrates another embodiment of connector  20  as Y-fitting  220 . Y-fitting  220  includes a main body  222  having a main portion  224  extending from a first end  226  to a second end  228 , and defining a main passageway  230  having an axis C-C and an outer surface  234 . Main body  222  further includes a branch portion  236  extending from main portion  224  at a branch end  240  to a third end  242  and defining a branch passageway  244  and an outer surface  246 .  
      Main portion  224  includes a generally cylindrical surface  260  defining the main passageway  230  with annular grooves  264  formed therein. Annular grooves  264  accommodate seals. Branch passageway  244  is in fluid communication with, and extends at a relative angle to, main passageway  230 . Branch portion  236  includes a connection port  272  for connecting branch portion  236  to a second conduit (not shown). The Y-fitting  220  accommodates either the hollow screw of  FIG. 2  or the aperture of  FIG. 3  to provide fluid communication between branch passageway  244  and main passageway  230 . First and second ends  226 ,  228  can be crimped as described above for securing connector  220  to a main conduit.  
       FIG. 5  illustrates a further embodiment of connector  20  as X-fitting  320 . X-fitting  320  includes a main body  322  having a main portion  324  extending from a first end  326  to a second end  328 , and defining a main passageway  330  having an axis D-D and an outer surface  334 . Main body  322  further includes a branch portion  336  and a second branch portion  338 . Branch portion  336  extends from main portion  324  at a branch end  340  to a third end  342  and defines a branch passageway  344  and an outer surface  346 . Second branch portion  338  extends from main portion  324  at a branch end  350  to a fourth end  352  and defines a second branch passageway  354  and a second outer surface  356 .  
      Main portion  324  includes a generally cylindrical surface  360  defining a main passageway with annular grooves  364  formed therein. Annular grooves  364  accommodate seals. Branch passageway  344  is in fluid communication with main passageway  330 . Branch portion  336  includes a connection port  372  for connecting branch portion  336  to a second conduit (not shown). Second branch portion  338  includes a connection port  374  for connecting second branch portion  338  to a second conduit (not shown) or for use as a drain, charging location, sample port, or test location. The X-fitting  320  would accommodate either the hollow screw of  FIG. 2  or the aperture of  FIG. 3  to provide fluid communication between branch passageway  344  and main passageway  330 . First and second ends  326 ,  328  can be crimped as described above for securing connector  320  to a main conduit.  
      An embodiment of coupling connector  320  to a main conduit involves inserting a main conduit into main passageway  330  and then inserting a piercing member, or second conduit,  376  into connecting port  372 . The second conduit  376  is provided with a piercing end  378  that can form an aperture in the main conduit and couple with the main conduit in such a manner so as to restrict relative axial movement between connector  320  and the main conduit. This connection may alleviate the need for crimping first and second ends  326 ,  328 . A hollow passage  382  allows an internal portion of the main conduit to be in fluid communication with the second conduit  376 . The piercing end  382  of the second conduit  376  may be self-tapping in order to form the aperture, or may be inserted into a pre-formed aperture. An exemplary piercing end is disclosed in U.S. Pat. No. 5,322,083, the disclosure of which is incorporated by reference in its entirety.  
      During installation of any of the disclosed connectors,  20 ,  120 ,  220 ,  320  seals, as desired, are positioned in annular grooves  64 ,  164 ,  264 ,  364 . The main conduit is inserted through main passageway  30 ,  130 ,  230 ,  330  as connector  20 ,  120 ,  220 ,  320  is radially and axially aligned with the main conduit to a desired location to form a coupling system. First end  26 ,  126 ,  226 ,  326  and second end  28 ,  128 ,  228 ,  328  are crimped, as desired, to secure connector  20 ,  120 ,  220 ,  320  to the main conduit. Thus assembled, connector  20 ,  120 ,  220 ,  320  provides a connection port  72 ,  172 ,  272 ,  372  to for main conduit. An aperture is formed in the main conduit, either before, after, or during the assembly of the main conduit and connector  20 ,  120 ,  220 ,  320 . The second conduit may be coupled with connection port  72 ,  172 ,  272 ,  372  to provide the coupling system with a fluid-tight connection between the main conduit and the second conduit.  
      Preferably, main body  22 ,  122 ,  222 ,  322  is constructed of steel and the coating is a zinc-nickel plating for corrosion resistance and to protect against other environmental concerns, although main body  22 ,  122 ,  222 ,  322  may be constructed of other materials such as brass, copper or aluminum. Coated steel is typically used in applications such as automotive power steering lines, and aluminum is typically used in automotive air conditioning lines.  
      The main axis of the couplings described herein may be straight or curved, as desired to accommodate a curved main conduit. While the connection port  72 ,  172 ,  272 ,  372  is described as connecting to a second conduit, it may be capped, or remain unconnected until the aperture is formed in the main conduit.  
      While the invention has been described with respect to specific examples including preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims.