Abstract:
A direct port connection for connecting a tube to a port without the use of an adapter fitting. A modified port design permits the use of prior art adapter fittings as well as the direct port connection of the present invention. Consequently, the invention permits the most efficient tube-to-port connection to be determined on an application-by-application basis at the time of making the connection.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to fittings for coupling a tube to another member. More particularly, the invention relates to fittings for hydraulic systems for connecting the end of a tube to a port. 
       BACKGROUND OF THE INVENTION 
       [0002]      FIG. 1  illustrates a known adapter fitting  10  for connecting a tube to a standard SAE port  15 . The adapter fitting  10  includes an adapter fitting body  20  having a port end  25  configured to be screwed into and sealed to the port  15 , a tube end  30  configured to receive an end of a tube  32 , and a passageway  35  between the ends of the fitting permits flow of fluid through the fitting. More particularly, the port end  25  of the fitting  10  has a threaded portion that mates with a threaded portion of the port such that the adapter body  20  can be screwed into the port  15 . An O-ring  40  is used to form a seal between the adapter body  20  and an angled seat surface  45  at the opening to the port  15 . The tube end  30  of the fitting  10  is provided with a male thread portion (threads are not shown) for mating with a tube nut  47 . The tube  32  is butted against the end face of the tube end  30  of the adapter fitting  10  and a sleeve  49 , an O-ring  50 , and the tube nut  47  are used to secure and seal the tube  30  to the adapter fitting  10 . 
         [0003]    Adapter fittings of the type just described are available for a wide variety of standard port designs and tube sizes. Further, such fittings are available in various shapes to suit a wide variety of applications. For example, as shown, 90 degree elbow fittings are available. The adapter fittings can also be connected to swivel mechanisms or other flexible members thereby providing even more versatility. 
         [0004]    Such prior art adapter fittings, however, typically have at least two potential leak points (e.g., the port-fitting seal and the fitting-tube seal) and require tightening of at least two threaded components to form the sealed connection. Further, in applications where space is a concern or a shaped or flexible fitting is not needed, the use of an adapter fitting can be problematic or represent an unnecessary cost. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a direct port connection for connecting a tube to a port in a body without the use of an adapter fitting. A preferred modified port design enables the use of prior art adapter fittings as well as the direct port connection of the present invention. Consequently, the invention allows the most efficient tube-to-port connection to be determined on an application-by-application basis at the time of making the connection. 
         [0006]    Accordingly, the present invention provides a port fitting assembly comprising a port body and an annular male nut through which a tube can extend. The port body has a bore opening to an outer surface of the body at an opening, an angled seat (e.g. a taper) surrounding the opening to the bore, a radially inwardly extending shoulder portion, and a female thread portion between the angled seat portion and the shoulder portion. The annular male nut is configured to trap a radially outwardly projecting flange on the end of a tube between an inner end of the male nut and the shoulder portion of the bore. The male nut includes a male thread portion for engaging the female thread portion of the bore such that the male nut can be tightened to hold the flange on the tube to the shoulder of the bore. 
         [0007]    An annular flange sealing member can be interposed between the shoulder of the bore and the flange on the tube to effect an annular seal therebetween. The flange sealing member may have an annular carrier body and an annular seal protruding axially from one and preferably both axial sides of the carrier body respectively for engaging the flange on the tube and the shoulder of the bore. The flange sealing member may also have at least one resilient retaining tab protruding radially outwardly from the relatively rigid annular body for engaging the inner diameter of the bore whereby the sealing member can be retained in the bore upon insertion into the bore. 
         [0008]    Preferably, the shoulder of the bore resides in a plane perpendicular to a center axis of the bore, and an annular nut sealing member is provided for sealing between the male nut and the angled seat. 
         [0009]    The port fitting assembly has particular application with a flange that is provided on the tube by means of a flange on a sleeve that is attached to an end of the tube. The sleeve preferably is joined to the tube by a fluid-tight connection, such as by welding or brazing. The sleeve may have a tubular portion, and the nut may have a counterbore therein for receiving the tubular portion of the sleeve. In another embodiment, the tube may have an end deformed to form the flange. In still another embodiment, a flange collar can be interposed between the tube and the nut for reducing torque transmission from the nut to the tube during tightening of the nut. 
         [0010]    According to another aspect of the invention, a method of connecting a tube to a port comprises the steps of (a) inserting a tube into a bore until a radially outwardly extending flange portion on the tube contacts a radially inwardly extending shoulder portion of the bore, and (b) tightening in the bore an annular male nut through which the tube extends, the male nut being configured to press the flange against the shoulder portion to form a seal. Preferably, an annular sealing member is inserted into the bore prior to inserting the tube into the bore. 
         [0011]    According to a further aspect of the invention, there is provided a port configuration for alternatively receiving a direct tube connect fitting assembly or a standard fitting adapter. The port comprises a bore that opens to an outer surface of a port body at an opening, an angled seat surrounding the opening of the bore, which angled seat provides a sealing surface for an annular adapter seal when an adapter is received in the bore, a radially inwardly extending shoulder to which the end of a flange on a tube can be sealed, the shoulder residing in a plane perpendicular to a central axis of the bore, and a female thread portion between the angled seat portion and the shoulder portion. In a preferred embodiment, the angled seat conforms to an SAE port fitting standard. Consequently, the type of tube fitting connection to be used need not be made at the time the port is formed in a port body. 
         [0012]    The foregoing and other features of the invention are hereinafter more fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a partially exploded cross-sectional view of a prior art adapter fitting shown installed in a port. 
           [0014]      FIG. 2  is a cross-sectional view of an exemplary direct port connection in accordance with the present invention. 
           [0015]      FIG. 3  is a top view of a sealing member used in the direct port connection. 
           [0016]      FIG. 4  is a cross-sectional view of the sealing member of  FIG. 3 . 
           [0017]      FIG. 5  is a cross-sectional view of a direct port connection according to the invention, wherein a flange on the tube is formed by a double-bumped end portion of the tube. 
           [0018]      FIG. 6  is a cross-sectional view of the direct port connection of  FIG. 2 , modified to include a flange collar. 
           [0019]      FIG. 7  is a cross-sectional view of a direct port connection, modified to include a sleeve attached to the tube end. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring now to the drawings in detail, in  FIG. 2  a direct port connection is illustrated and generally indicated by reference numeral  110 . The direct port connection is an assembly that includes a port body  115  having a bore  120  forming a port. The port body may have additional ports and flow passages aside from the port  120 . The bore  120  includes a counterbore portion  122  and an angled seat  125  surrounding a bore opening  130 . The bore  120  further includes a radially inwardly extending shoulder portion  135  formed by the intersection of a larger diameter, axially outer bore portion with a smaller diameter internal flow passage in the port body  115 . The bore  120  also has a female thread portion  140  located axially between the angled seat portion  125  and the shoulder portion  135 . The female thread portion  140  is provided for threaded engagement with a male thread portion  160  of a male nut  145 . 
         [0021]    The male nut  145  has an axially extending through bore through which a tube  150  extends. The bore in the male nut  145  preferably is sized so that it can be freely rotated about the tube  150  generally without resistance that otherwise might make tightening of the male nut  145  more difficult or impart an unwanted torque on the tube  150 . Accordingly, the inside diameter of the male nut  145  may be slightly larger than the outside diameter of the tube  150 . 
         [0022]    The male nut  145  includes a head portion  155  and the external thread portion  160  that can be threaded into the bore  120 . The head portion  155  preferably is provided with wrenching surfaces to facilitate rotation and tightening of the male nut  145  in the bore  120 . 
         [0023]    The male nut  145  has an inner end surface  147  for engaging a radially outwardly extending flange  165  on the tube  150 . As will be described herein, the flange  165  can be formed integrally with the tube  150 , or can be part of a separate member attached to the tube  150 . In  FIG. 2 , the flange  165  is formed by outwardly deforming the end of the tube  150  to form a radially extending flange  165  that preferably is perpendicular to the center axis of the tube  150 . While the illustrated flange  165  extends generally perpendicular (radially outwardly) from the length of the tube  150 , the flange  165  could extend from the tube  150  at other angles. 
         [0024]    The flange  165  abuts an annular sealing member  168  that is interposed between the flange  165  and the shoulder  135  of the bore  120 . Accordingly, when the male nut  145  is tightened, the sealing member  168  is compressed between the flange  165  and the shoulder  135  thereby sealing the tube  150  and bore  120 . For this purpose, the shoulder  135  preferably resides in a plane perpendicular to the center axis of the bore  120 . That is, the shoulder surface that is engaged by the sealing member  168  is perpendicular to the bore&#39;s center axis. The annular sealing member  168  may be a separate piece that is inserted into the bore  120  prior to insertion of the tube  150  and male nut  145 , or it may be joined to the flange  165  or a surface of the shoulder  135 . 
         [0025]    Any suitable sealing member  168  may be employed, such as that illustrated in detail in  FIGS. 3 and 4 , which heretofore has been used in other types of tube connections. The sealing member  168  generally includes an annular carrier body  170  and seal  171  bonded to an inner edge thereof. The illustrated seal  171  protrudes axially from both axial sides of the carrier body  170 , and can be an elastomeric material, such as rubber. Resilient radially outwardly extending retaining tabs  173  are provided around an outer edge  174  of the body  170 . After insertion of the sealing member  168  into a bore, such as bore  120 , the resilient tabs  173  function to retain the sealing member  168  therein. Accordingly, and as desired, the sealing member  168  can be inserted into the bore  120  in advance of assembly of the direct port connection  110 . It will be appreciated that the present invention is not limited to the use of the sealing member  168  and that other types of sealing members can be used in accordance with the present invention. 
         [0026]    Returning to  FIG. 2 , another sealing member, such as an O-ring  175 , can optionally be provided to seal a surface of the male nut  145  to the angled seat portion  125  of the bore  120 . The O-ring  175  generally functions to prevent dirt and/or moisture from entering the bore  120 , and may provide a secondary sealing function to prevent leakage from the bore  120 . 
         [0027]    To assemble the direct port connection  110 , the sealing member  168  is inserted into the bore  120 . As described, tabs  173  can be provided on the sealing member  168  for retaining the sealing member  168  in the bore  120  prior to assembly of the direct port connection  110 . Accordingly, the sealing member  168  can be inserted into the bore  120  well in advance of final assembly of the direct port connection  110 . After inserting the sealing member  168  into the bore  120 , the male nut  145 , with the tube  150  inserted therethrough, is screwed into the bore  120  until the flange  165  contacts the seal member  168 . The male nut  145  is tightened to press the flange  165  and the sealing member  168  against the shoulder portion  135 , thereby to effect a seal between the end of the tube and the port body  115 . 
         [0028]    Turning to the remaining figures, in  FIG. 5  another direct port connection  110  is shown. The direct port connection  110  is identical to the direct port connection of  FIG. 2  (corresponding components have been given the same reference numerals in FIGS.  2  and  5 - 7 ) except that the flange  165  in  FIG. 5  is formed by a double bumping process wherein the end of the tube  150  is rolled outwardly and then turned inwardly to form the flange  165  as shown. 
         [0029]      FIG. 6  is another direct port connection  110 , identical to the direct port connection of  FIG. 2 , except that a flange collar  180  is interposed between the tube  150  and the male nut  145 . The flange collar  180  is generally annular and engages the flange  165  on the tube  150 . The male nut  145  includes a counterbore for receiving the flange collar  180 . The flange collar  180  provides a surface against which the male nut  145  can slide when being tightened to thereby mitigate torque transfer from the male nut  145  to the tube  150  during tightening. Accordingly, the flange collar  180  can prevent twisting of the tube  150  during assembly and/or disassembly of the direct port connection  110 . 
         [0030]    Turning to  FIG. 7 , yet another direct port connection is illustrated. The direct port connection  110  is identical to that described and shown in  FIG. 2 , except that the flange  165  is formed by a flange sleeve  190  that is connected to the tube  150 . The sleeve  190  preferably is joined to the tube  150  by a fluid-tight connection, such as by welding or brazing. The sleeve  190  has a tubular portion, and the male nut  145  has a counterbore therein for receiving the tubular portion of the sleeve  190 . 
         [0031]    It will now be appreciated that the direct port connection  110  of the present invention provides a connection that, compared to traditional adapter fittings, is more economic and compact, reduces potential leak points, and requires fewer parts to be assembled. 
         [0032]    Further, it also will be appreciated that the shape of the bore  120 , including the angled seat portion  125  and shoulder portion  135 , permits the use of a direct port connection as set forth, as well as a conventional adapter fitting  10  as shown and described in connection with  FIG. 1 . The ability of the bore  120  to accept both types of connections allows the end-user to select the appropriate connection for a given application. Thus, if an adapter fitting is desired or necessary, the end-user may install an adapter fitting without the need to modify the bore  120 . Alternatively, if a direct connection is desired or necessary, the end-user can install the direct port connection  110  of the present invention. 
         [0033]    It will now be appreciated that a port can be configured in the manner set forth to accommodate a direct port connection as described, as well as traditional adaptor style connectors. Consequently, the present invention provides for the use of fittings already in use in the field, as well as the direct port connection as described. Standard ports are those for which specifications have been adopted by industry-recognized agencies such as SAE, ISO, BS and JIS. 
         [0034]    The various embodiments of the invention have been described in relation to a tube. Unless otherwise indicated, the term “tube” or “tubes” is intended to encompass not only a tube or tubes, but also tubing, tubular fittings provided on the ends of hoses, and like tubular members, including those of generally uniform diameter extending from an end flange on the tubular member. 
         [0035]    Although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.