Abstract:
The recess ( 12 ) between the main connecting part ( 8 ) and a collar ( 9 ) contains a toroidal or otherwise shaped sealing ring or joint ( 3 ) and the end of a tube ( 1 ) incorporating an outer flange ( 2 ), whose thickness becomes zero at the crushing bulge ( 4 ) of the sealing ring ( 3 ). An excellent seal is ensured at this location, even for pressurized fluids, and the assembly can easily be dismantled.

Description:
DESCRIPTION  
         [0001]    The present invention relates to the connection of a micro-tube to a structure.  
           [0002]    The tubes in question can be flexible, rigid or semi-rigid, have a very small diameter of approximately one millimetre and are able to carry gaseous or liquid fluids at a pressure of several bars.  
           [0003]    The sealing at the ends of such micro-tubes is not then easy to ensure in an appropriate manner and requires either crimping, which reduces the opening cross-section of the tube, or complicated and costly fitting, or bonding, which does not permit an easy replacement of the tubes.  
           [0004]    The present invention proposes a simple, reliable and dismantlable connection. It is characterized in that it comprises an elastic, cambered joint surrounding the micro-tube, a flange fashioned around the micro-tube tapering out of the micro-tube and extending up to a bulging circumference of the joint, and a collar on the structure, joined to such structure whilst forming a recess in which the joint is held between the faces of the recess on which it bears, the flange bearing on one of said faces.  
           [0005]    The flange bearing on one of the faces of the recess ensures a good sealing at this location and this is perfected by the joint which, compressed in the recess in the axial direction of the micro-tube, presses the flange against said face of the recess, whilst offering a supplementary sealing ring around the flange.  
           [0006]    Other features, characteristics and advantages of the invention will be described with reference to the attached drawings. 
       
    
    
       [0007]    [0007]FIG. 1 shows in cross-section an embodiment of the invention, FIGS. 1A and 1B show two variants of FIG. 1 and FIGS. 2 and 3 show an embodiment of the turned-up flange.  
         [0008]    A micro-tube  1  is shown in FIG. 1 and terminates in a turned-up flange  2  held in the connection forming the subject matter of the invention. The turned-up flange  2  is in one piece with the micro-tube  1 . The connection of the microtube  1  also comprises a sealing ring or joint  3 , which can be toroidal in the free state and has opposing bulges  4  and  5  bearing on two faces, respectively  6  and  7 , of a main structural part  8  and a collar  9 . The main structure part  8  carries a channel  10  extended by the micro-tube  1 . The turned-up flange  2  bears on the surface  6  of said main structural part  3 , the joint  3  is placed on the turned-up flange  2  and the collar  9  is placed on the joint  3  in order to compress the latter and secure the turned-up flange  2  whilst maintaining it on the face  6 . The main structural part  8  can be joined to the collar  9  by a thread  11  on their surfaces making it possible to join them directly by screwing and to move them together as desired by regulating the height of a recess  12  defined by the faces  6  and  7 . The collar  9  and structure  8  can be pressed or moved together by any linking means other than direct securing obtained with the aid of the thread  11  referred to in exemplified manner here.  
         [0009]    The joint  3  is introduced onto the micro-tube  1  and bears on the turned-up flange  2 . Its small diameter is substantially equal to the external diameter of tube  1  and the turned-up flange  2  tapers continuously towards the outside (on moving away from the micro-tube  1 ) and is cancelled out at a diameter corresponding to that of the bulge  4 . 
     
    
       [0010]    In a preferred embodiment, the mean diameter of the toroidal sealing ring  3  is approximately equal to the external diameter of the turned-up flange  2 , so as to ensure a pressure on said flange  2  and the sealing between said flange and the face  6  of the structure  8 .  
         [0011]    As the joint  3  is pressed by the collar  9 , as a consequence it presses the turned-up flange  2  against the opposite surface  6 , thus opposing a detachment under the pressure of the fluid flowing through the micro-tube  1  and channel  10  of the main part  8  and tending to separate them. Sealing is mainly produced at the bulge  8  and experience has proved that it remains for fluid pressures reaching  10  bars. In the case of a high fluid pressure, it is advantageous to place the joint  3  in a recess  14 ,  15  made either on the face  7  of the collar  9 , or on the face  6  of the structure  8 , so that the areas round the corresponding bulge  4  or  5  of the joint  3  penetrate the same and the radial expansion of the joint  3  is in this way combatted. The recesses  14  and  15  are illustrated in FIGS. 1A and 1B. Unlike the recess  12 , they provide support to the periphery of the joint  3 . Normally the main structural part  8  is used for multiple connections and has numerous channels  10  connected to the same number of micro-tubes  1  and the recess  12  is wide enough to include the network of connected micro-tubes  1 . A circle of screws is then used for joining the collar  9  to the main structural part  8 . In other variants, the collar  9  could have an external thread and the main part  8  an internal thread, unlike what is shown here, or other known means for creating these two parts and for moving them together.  
         [0012]    A production method for the turned-up flange  2  will be described relative to FIGS. 2 and 3. The micro-tube  1  is inserted in a slot  16  of a die  17  in such a way that its end points somewhat to the outside. A conical punch  18  is introduced into the projecting end and widens it. A flat punch  19  (which can be an opposite face thereof) is then pressed onto the upper face of the die  17  crushing the end of the micro-tube  1  against said surface, which gives the turned-up flange  2  of FIG. 1.  
         [0013]    This process is suitable for most micro-tube materials. However, others can be used, more particularly if the micro-tube  1  is flexible. It can then be hardened by heating or some other means, as a function of its composition, once the deformation has taken place. It is also possible to use glass micro-tubes. The aforementioned process will be accompanied by a heating operation in order to soften the glass.  
         [0014]    Generally the flanges are produced by a permanent material deformation process.  
         [0015]    The sealing ring or joint  3  illustrated is toroidal. Cross-sections other than circular are suitable provided that they have bulges bearing on the opposite faces  6  and  7  of the recess  12  in order to press the flange  2  against the face  6 . In the same way a flange  2  is shown stopping at the diameter of the joint  3  corresponding to the greatest height (between bulges  4  and  5 ), but it is unnecessary to precisely respect this condition and the flange  2  could be slightly wider or narrower. However, the configuration shown is preferred.