Abstract:
A coupling, comprised of a tube with an attached tubular shell, for attachment with external components. The tube has a first end, second end and a longitudinal bore extending therethrough. The tube further includes an intermediate portion between the first and second ends having spaced radially outwardly extending annular beads. The tubular shell has a first portion axially confined between the annular beads and has an inner surface with a first axial end and a second axial end, wherein one of the first and the second inner axial ends has a non-rounded shape. The shell has a second portion extending axially from the first portion to a free end and has an inner surface spaced radially and coaxially outwardly of the exterior of the tube second end to define an annular recess therebetween and is adapted to be inwardly deformed toward the tube second end.

Description:
CROSS-REFERENCE TO RELATED CASES  
       [0001]    The present application claims the benefit of the filing date of U.S. Provisional Application Serial No. 60/442,320 filed Jan. 23, 2003. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The field of art to which this invention pertains includes that of hose couplings for attachment with fluid conductors.  
         BACKGROUND OF THE INVENTION  
         [0003]    Fittings are used as connectors in order to link fluid conductors with each other. Fittings generally include a tubular element, or tube, having two ends. The first tube end has an outer surface designed to maintain a swivel nut in a predetermined axial location while allowing the swivel nut to rotate. The second tube end has an outer surface which affixedly retains a tubular shell that circumferentially surrounds this end.  
           [0004]    The usually externally hexagonally shaped swivel nut typically has internal threads that serve for attachment to the male port end of a fluid conductor. The swivel nut is sealingly fastened onto the noted male port end with a torquing device to a predetermined tightness. During this fastening process the inner end surface of the swivel nut comes into contact with its adjoining tube end such that friction between the two components will cause the entire tube to rotate with the swivel nut. Typically, prior art fittings include a hexagonal holding surface provided on the tube itself so that the user can hold the tube, via this holding surface, in a static or fixed position while tightening the swivel nut. By virtue of holding the tube in a static position, the desired angle, or orientation of the fitting is maintained. A cost disadvantage associated with the tube holding surface is that this entails another machining or forming process in order to provide such a hexagonal surface on an otherwise cylindrical tube.  
           [0005]    The second end of the tube has an end portion that is adapted to be inserted into a conduit. The surrounding shell, which is attached to the second end of the tube, surrounds the conduit. The conduit, or course, is the fluid conductor that is used to transfer fluid from one location to another. Typically, this conduit is flexible so that the fluid can be transferred in multiple directions or angulations without the awkward bending of a rigid pipe. In order to attach the conduit to the fitting, the shell is inwardly deformed so that the intermediate conduit portion is compressed between the shell and the tube.  
           [0006]    Rather than providing the tube element with a hexagonally-shaped outer surface, some prior art fittings provide a hexagonally-shaped holding surface on the shell itself. Examples of such a shell are shown in U.S. Pat. No. 4,804,212 to Vyse, which is also assigned to the assignee of the present invention, U.S. Pat. No. 5,317,799 to Chapman et al., and in published PCT Application No. WO 94/18487 to Shiery. These prior art references have hexagonal outer surfaces on the shell which are formed during the inward deformation, or crimping, of the shell onto the conduit. The disadvantage of this type of shell is that the shell can still rotate relative to the conduit and tube while it is being held.  
           [0007]    Shells can be fixedly attached to the tube by several methods. As is well known in the art, the inner axial end of the shell can be inwardly deformed, or crimped, onto the tube so that it is compressively attached. Other methods include radially compressing an inwardly directed shoulder of the shell into an annular groove in the tube. This is shown in the previously mentioned U.S. Pat. No. 4,804,212 to Vyse.  
           [0008]    Another method of affixing the shell to the tube includes axially compressing an inwardly directed shoulder of the shell between two radially outwardly extending protuberant surfaces, such as annularly formed beads. Examples of such an attachment are shown in U.S. Pat. No. 3,924,883 to Frank; U.S. Pat. No. 6,270,126 B1 to Juedes; and Japanese Pat. No. 5-118483 to Funato. Although these constructions may axially limit the movement of the shell relative to the tube, a disadvantage arises when the tube starts to rotate with the nut during its torquing. The installer will try to hold the shell static in order to prevent its rotation and linear misalignment. Although the shell has been inwardly compressed onto the conduit, it may still rotate relative to the conduit (and/or tube) if its contact with the tube does not prevent same. For example, if the inner surface of the shell shoulder is circular, the shell may be able to rotate relative to a cylindrical tube.  
         SUMMARY OF THE PRESENT INVENTION  
         [0009]    The present invention provides a coupling for attachment to a conduit. The coupling has a longitudinal axis and is comprised of a tube and an attached tubular shell. This invention overcomes the obstacle of shell rotation relative to the tube, and tube movement during fixed attachment of the coupling to a mating end.  
           [0010]    A feature of the present invention is to provide coupling where the tube has a first end, a second end and a longitudinal bore extending from the first end to the second end which is adapted for insertion into the conduit. The tube further includes an intermediate portion between the first and second ends having spaced first and second radially outwardly extending annular beads. The coupling is further comprised of a tubular shell having a first portion and a second portion. The first portion is axially confined between the first and second annular beads and has an inner surface with a first axial end and a second axial end, wherein one of the first and the second inner axial ends has a non-rounded shape. The shell second portion extends axially from the first portion to a free end and has an inner surface spaced radially and coaxially outwardly of the exterior of the tube second end to define an annular recess therebetween and is adapted to be inwardly deformed toward the tube second end.  
           [0011]    A further feature of the noted coupling includes having at least one of the first and second non-rounded shaped inner surface axial ends being an elliptical shaped undercut located at the proximal end of the first portion. Another feature includes having an abutting portion of the first bead being permanently deformed into a similar shape as the adjoining elliptical shaped undercut as a result of formation of the second bead.  
           [0012]    Still another feature of the noted coupling has at least an axial portion of the tube being other than straight. A further feature of the noted coupling has the tubular shell first portion having an exterior surface with a plurality of angularly spaced flat portions forming retaining flats.  
           [0013]    Another feature of the noted coupling has the tubular shell first portion being comprised of two parts, a first surrounding part and an annular insert. The surrounding part has a longitudinal segment extending from the tubular shell second portion and a substantially radial segment having an end abutting the outer surface of the tube with an outer surface in contact with the first radially outwardly extending annular bead. The annular insert is axially symmetrical and has an outer surface in contact with the inner surface of the longitudinal segment. The annular insert further has a first annular surface in contact with the inner surface of the radial segment, and a second annular surface in contact with the second radially outwardly extending annular bead.  
           [0014]    Still yet another feature of the noted coupling has the at least one non-rounded shaped inner surface of the tubular shell preventing the shell from rotating relative to the tube as a result of the formation of the second bead. The formation causes the permanent deformation of the abutting portion of the adjacent one of said first and second beads into a similar or conforming shape with said non-rounded shaped inner surface. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a longitudinal cross-sectional view of a fitting, having an angular orientation, according to the present invention.  
         [0016]    [0016]FIG. 2 is a longitudinal cross-sectional view of a tube element and an attached tubular shell according to the present invention.  
         [0017]    [0017]FIG. 3 is a cross-sectional view of a straight fitting, similar to that as shown in FIG. 2, with an added nut element, assembled according to the present invention.  
         [0018]    [0018]FIG. 4 is a perspective view of the shell according to the present invention.  
         [0019]    [0019]FIG. 5 is a perspective view of the tube element and attached shell according to the present invention.  
         [0020]    [0020]FIG. 6 is a longitudinal cross-sectional view of the shell taken along line  6 - 6  in FIG. 7.  
         [0021]    [0021]FIG. 7 is an enlarged frontal view of the shell of the present invention.  
         [0022]    [0022]FIG. 8 is a further embodiment of the present invention, showing a partial view of a fitting in cross-section, particularly detailing the connection of a tube, an insert and a shell.  
         [0023]    [0023]FIG. 9 is a side, cross-sectional view of the insert, taken along line  9 - 9  in FIG. 10.  
         [0024]    [0024]FIG. 10 is an enlarged frontal view of the insert of FIG. 9. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    Referring now to the drawings and particularly to FIG. 1, there is shown a longitudinal cross-section of a fitting  20 , generally constructed of metal. Fitting  20  is comprised of a tube  30  with a rigidly attached shell  50  and rotatably attached, or swivel nut  90 . In FIG. 1 tube  30  is shown bent at an about 45° angle, although tube  30  can take any desired angled or straight orientation, e.g. a straight variation as shown in FIG. 3. Shell  50  is attached to a first end  35  of tube  30 . Nut  90  is attached to a second end  42  of tube  30 .  
         [0026]    Fitting  20  is typically used to fluidly connect a fluid conductor, e.g. a conduit, to a port or to another fluid conductor. Tube first end  35 , and shell  50 , receive the conduit, (not shown), such that tube first end  35  is inserted into the conduit and shell  50  circumferentially surrounds an equivalent length portion of the conduit. The conduit is longitudinally inserted or interposed into an annular space  55  between tube first end  35  and shell  50  so that it contacts an angled inner surface of an annular transition portion  58  thereof. The full peripheral extent of shell  50  is inwardly deformed such that conduit is compressively retained or sandwiched between shell  50  and tube  30 .  
         [0027]    Referring now to FIGS. 4 and 6, shell  50  is comprised of a first portion  51  and a second portion  53  joined via annular portion  58 . First portion  51  has an outer surface with a plurality of spaced retaining or wrench flats  60  along its periphery for gripping with a retaining tool, such as a wrench. An annular surface  62  is located at the proximal or outer end of first portion  51  and has a non-rounded, or oval, inner diameter defined by an inner elliptical surface, or undercut,  64  that is best shown in FIG. 7. Inner elliptical undercut  64  has a first radius r 1  and a larger second radius r 2  which together, provide, and define its oval shape. A flat, circular, cylindrical, inner surface  68  is adjacent elliptical undercut  64  and separates undercut  64  from an annular rounded groove  72  formed along the inner surface of first portion  51 . The axial extent of surface  68  is substantially greater than that of both undercut  64  and groove  72 . A stepped portion  76  is provided between rounded groove  72  and inner surface of annular transition portion  58 , with portion  58  providing the transition from shell first portion  51  to shell second portion  53 .  
         [0028]    Shell second portion  53  has a smooth outer surface prior to being inwardly deformed onto a conduit (not shown). Spaced pluralities of inwardly directed teeth or spikes  57  are located on the inside surface of second portion  53  and serve to grip the conduit upon the inward deformation of shell  50 . An inner rounded protuberance  56  is located at the distal or outer end of second shell portion  53  and provides a seal between shell  50  and the conduit.  
         [0029]    Referring to FIGS. 1 and 3, nut  90  has a first or inner end  91  that is axially retained on tube second end  42  while still being able to swivel. Typically a second or outer end  92  of nut  90  is adapted to be attachable to another fluid conductor, e.g. an externally threaded fixed male port (not shown), by means of an internal threaded connection portion  94 . Nut  90  typically has a series of spaced flat external surface portions, e.g. hex flats, for gripping with a retaining tool, such as a wrench in order to supply torque while tightening same. A contoured sleeve  89  is positioned and fixedly retained between nut  90  and tube second end  42  in order to support nut  90 .  
         [0030]    Prior to the attachment of nut  90  onto a mating male end, the conduit (not shown) is attached to fitting  20 . Typically the conduit is positioned at a predetermined desired angle for proper installation while nut  90  is threaded onto its mating surface. For example, in order to prevent kinking of the conduit, or to prevent abrasion to its outside surface, the conduit is routed from one connector to the next in a predetermined fashion. Therefore, it is important for the conduit to remain correctly positioned or located during the threading attachment of nut  90 . In order to threadingly attach nut  90  onto its mating port, torque is supplied to nut  90  until it reaches a predetermined sealing value. As is well known in the art, during this torquing process the friction between nut  90 , sleeve  89  and tube  30  is increased such that input torque (e.g. by the wrench) is transferred to tube  30  and will cause tube  30  to rotate in the direction of the supplied torque. Since shell  50  is attached to tube  30 , and the conduit is compressed between shell  50  and tube  30 , the conduit will also rotate or move with the input torque, unless fitting  20  is held fixed while torque is supplied. Since the majority of fitting  20  is rounded, it is difficult to hold fitting  20  in place. For this reason, wrench flats  60  are provided on shell  50  so that the installer can hold fitting  20  in place, i.e. against rotation, during the torquing process.  
         [0031]    The transfer torque is even more pronounced when tube  30  has an angular component, such as the 45° orientation, shown in FIG. 1, than when it is straight, as shown in FIG. 3. In these cases, if the installer happens to restrain the conduit during the attachment of nut  90  onto its connecting end, the conduit will twist, thus causing structural damage. Many times the conduit will be affixed at its other end, so any rotational movement of the conduit in this instance will be damaging. If the conduit is attached to angled fitting (as shown in FIG. 1), the conduit tends to kink at the point where it leaves fitting  20  if it is held during the torquing of nut  90 . Thus the gripping of wrench flats  60 , to immobilize fitting  20  during the torquing of nut  90  is not only advantageous for retaining the desired direction of the conduit, but it also helps prevent damage to the conduit itself.  
         [0032]    It is equally important that shell  50  not rotate relative to tube  30  at any time during the attachment of nut  90  onto a mating male end or connecting port. Referring to FIG. 3, when the installer immobilizes wrench flats  60 , against rotation, during the installation of nut  90  onto its connecting port, shell  50  and tube  30  should not rotate relative to each other. Such rotation can occur when nut  90  is so tight on its connecting port such that the friction between nut  90 , sleeve  89  and tube  30  is great enough to cause tube  30  to rotate with nut  90 . If shell  50  is not securely rotationally affixed to tube  30 , it may turn relative to tube  30 . This will cause damage to the conduit, since teeth  57  will lose their grip on the conduit thus possibly providing a leak path. Further more, the sealing connection between shell  50  and tube  30 , located at the contact area of the inner surface of shell first portion  51  with tube  30 , may be damaged if tube  30  rotates relative to shell  50 .  
         [0033]    Referring now to FIGS. 6 and 7, in order to prevent the noted rotation, shell first portion  51  is designed with an oval shaped inner diameter. Inner elliptical undercut  64  is shown with a first radius r 1  and a second radius r 2 . R 1  defines the smallest radial extent of elliptical inner surface, while r 2  defines the largest extent. As will be discussed below, elliptical inner undercut  64  abuts a formed first radially outwardly extending annular bead  32  (as shown in FIG. 2) and is prevented from rotating relative to tube  30 .  
         [0034]    Referring to FIGS. 2, 4 and  5 , the formation of fitting  20  will now be discussed. First bead  32 , which extends around the circumference of tube  30 , is initially formed the outer surface thereof by any desired technique, such as by use of a punch tool. The width of first bead  32  is greater than twice the wall thickness of tube  30 . Shell  50  is placed over tube end  35  so that elliptical inner undercut  64  is in abutting contact with bead  32 . A second radially outwardly extending annular bead  34  is then formed, in a similar fashion as bead  32 , and presses into annular rounded groove  72  (shown in FIG. 6). Similar to first bead  32 , the width of second bead  34  is greater than twice the wall thickness of tube  30 . Formation of second bead  34  compresses shell flat inner surface  68  between first and second beads  32 ,  34 . Due to the force transferred during the formation of second bead  34 , elliptical inner undercut  64  is axially and fixedly pressed into first bead  32  via permanent deformation or press-fitting thereof. This force causes first bead  32  to take a similar or conforming shape, i.e. oval, as undercut  64 . The abutting contact between now conformably-deformed first bead  32  and elliptical inner undercut  64  prevents any rotational movement of shell  50  relative to tube  30 .  
         [0035]    The compression of flat inner surface  68  between first and second beads  32 , 34  also prevents any axial movement of shell  50  relative to tube  30 . The thickness of flat inner surface  68 , and the corresponding volume of material of shell first portion  51  between beads  32  and  34 , allows shell  50  to withstand stresses transferred from the attached conduit when high-pressure fluids are transmitted within the conduit and when there is axial movement of the conduit. If flat inner surface  68 , or shell first portion  51 , are of insufficient thickness, pressures or axial forces exerted on the conduit would cause shell first portion  51  to deflect in the direction of the force, thus damaging the sealing and retention capabilities of fitting  20 .  
         [0036]    Referring again to FIGS. 2 and 3, contoured sleeve  89  and surrounding nut  90  are slipped onto tube  30  at second end  42 . A face seal end  44  is formed in tube end  42  in order to hold sleeve  89  and nut  90  axially in place, relative to tube  30 . Depending on the desired configuration of fitting  20 , tube  30  can then be bent to the required angle or orientation, such as that shown in FIG. 1.  
         [0037]    Referring now to FIGS. 8, 9 and  10 , a further embodiment  120  is shown therein. Fitting  120  is similar to fitting  20  described above, with the exception of an added insert  140  and a modified shell  150 . Fitting  120  utilizes a tube  130  with two beads,  132  and  134 , similar to tube  30  of fitting  20 . Shell  150  has a first portion  151  and a second portion  153 . Second portion  153  has a design similar to that of shell second portion  53 , with a series of circumferential teeth  157  and a rounded surface  156  along its inner surface, and thus need not be discussed further.  
         [0038]    The wall thickness of shell first portion  151  is constant throughout and has the same thickness as second portion  153 , excluding teeth  157  and rounded surface portion  156 . Shell first portion  151  includes a section  152  parallel with the longitudinal axis of fitting  120 , having a depending shoulder  159  with an inner inwardly directed surface  161  which defines the smallest inner diameter of shell  150 . Resembling the previously described wrench flats surface  60  of shell  50 , shell first portion longitudinal section  152  similarly has an outer surface with a plurality of spaced retaining or wrench flats  160 . Longitudinal section  152  has a non-rounded inner surface  154  axially extending from depending shoulder  159  to an angled inner wall of transition portion  158 .  
         [0039]    Insert  140  is axially symmetrical, having an annular surface  162  and an inner non-rounded, or elliptical, undercut  164  on both axial end faces. As an example, undercut  164  can have an oval shaped inner diameter with a first radius r 1 ′ and a second radius r 2 ′. R 1 ′ signifies the smallest radial extent of undercut  164 , while r 2 ′ is the largest extent. Shell first portion  151 , together with shoulder  159  thereof, surrounds one annular surface  162  and an outer peripheral surface  166  of insert  140 . Insert outer surface  166  is non-rounded and shaped similarly and conforms to that of adjacent first portion inner surface  154 . For example, both insert outer surface  166  and longitudinal section inner surface  154  can have a hexagonal shape (as shown in FIG. 10) so that insert  140  cannot rotate relative to shell  150 .  
         [0040]    The assembly of fitting  120  will now be discussed. Similar to the formation of fitting  20 , first bead  132  is formed within tube  130  and has a width greater than twice the wall thickness of tube  130 . Shell  150  is slipped onto the outer surface of tube  130  so that one side of its depending shoulder  159  abuts one side of first bead  132  and its inwardly directed surface  161  contacts the outer surface of tube  130 . Insert  140  is slipped onto the outer surface of tube  130  and positioned in abutting contact with the other side of depending shoulder  159 . As mentioned above, insert outer peripheral surface  166  and shell inner peripheral surface  154  have similar conforming non-rounded shapes so that after insert  140  is press-fitted inside shell  150  it cannot rotate relative thereto. Due to its symmetrical design, insert  140  can be axially arranged either way without causing an assembly error. Thereafter, second bead  134  is formed, e.g. by means of a punch tool, and is fixedly pressed into elliptical undercut  164 . At least the abutting portion of second bead  134  takes the form of elliptical undercut  164  as it is pressed thereinto, via permanent deformation thereof. The transfer force from the formation of second bead  134  axially compresses depending shoulder  159  between first bead  132  and insert  140 , thus axially retaining shell  150  on tube  130 .  
         [0041]    For the same reasons as discussed above, retaining or wrench flats  160  provide a holding area for a wrench or similar tool during the affixing of the nut (see  90  in FIG. 3) onto its mating connection. By retaining fitting  120  in a fixed position or location during installation prevents misalignment of the conduit and damage thereto. Also as stated above, the fixed retention of insert  140 , and the affixing of shell  150 , onto tube  130  prevents both axial and rotational movements of insert  140 , and shell  150 , relative to tube  130 . This stops leakage between shell  150 , tube  130  and the conduit.  
         [0042]    Referring again to FIGS. 1 and 6, it should be noted that although fitting  20  has been described with non-rounded undercut  64  located at the proximal end of first portion  51  and with annular rounded groove  72  formed at the opposite end of first portion  51 , these inner annular shaped portions can be reversed so that the inner proximal end of first portion  51  is rounded and the inner distal end of first portion  51  is non-rounded. Such a design is similar to that of fitting  120  and would function similarly, i.e. with regard to the retention of shell  50  on tube  30  so as to prohibit both axial and rotational movements of shell  50  relative to tube  30 .