Abstract:
A connecting arrangement has end sections of two fluid conduits to be connected to one another and a coupling element having an axis and an outer side surrounding the axis and an inner side surrounding the axis. On the circumference of the end sections first securing ribs extend in the circumferential direction. On the inner side of the coupling element second securing ribs extending in the circumferential direction are provided proximal to each axial end of the coupling element. The coupling element is coaxially coupled to the end sections in the coupled state of the connecting arrangement by being elastically expanded, wherein the second securing ribs lock behind the first securing ribs and the end sections are coupled seal-tightly with one another. The coupling element is a circular cylindrical sleeve that is closed circumferentially.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The invention relates to a connecting arrangement comprising end sections of two fluid conduits to be connected to one another and comprising a coupling element having an outer side extending about an axis and an inner side extending about the axis. First securing ribs extend in the circumferential direction about the circumference of the end sections; second securing ribs extend in the circumferential direction on the inner side of the coupling element in the vicinity of each axial end of the coupling element. The coupling element is coaxially coupled by being elastically widened to the end sections and one end section is seal-tightly coupled coaxially to the other end section, wherein the second securing ribs are locked behind the first securing ribs in the coupled position.  
         [0003]     2. Description of the Related Art  
         [0004]     In a connecting arrangement of this kind disclosed in European patent application 1 378 701 A1, the coupling element is made from an elastic plastic material and is comprised of two oval rings connected to one another by two diametrically opposed stays. The rings are provided internally with securing ribs in the form of locking noses. Upon insertion of the end sections of the fluid conduits into the rings, the rings are elastically widened by means of the securing ribs provided on the end sections until the locking noses of the rings lock behind the securing ribs of the end sections. In the coupled state, there is play between the ring areas having the smaller radius of curvature and the end sections; the play enables radial compression of the rings for decoupling. Because of the wide intermediate spaces between the stays and the play for decoupling between the rings and the end sections, there is the risk that the end sections of the fluid conduits inserted into the coupling element become soiled. This can cause difficulties for repeated coupling and decoupling. Moreover, there is the risk that the connection will become detached when transverse forces in opposite directions are exerted onto the end sections.  
       SUMMARY OF THE INVENTION  
       [0005]     It is an object of the present invention to provide a connecting arrangement of the aforementioned kind that prevents the risk of soiling of the connecting location of the end sections and also prevents accidental decoupling.  
         [0006]     In accordance with the present invention, this is achieved in that the coupling element is a circumferentially closed circular cylindrical sleeve.  
         [0007]     With this configuration, the sleeve provides an additional sealing action of the connecting location of the end sections in regard to soiling as well as for additional reinforcement of this connecting location in regard to transverse forces.  
         [0008]     Preferably, it is provided that the sleeve has bending-resistant sleeve segments that extend about at least 80 E and less than 180 E in the circumferential direction and have neighboring edges that are connected, respectively, by elastic sleeve segments comprising elastically expandable material by being fused thereto or by forming a monolithic part. The bending-resistant sleeve segments contribute an additional reinforcement of the sleeve and thus of the connecting location of the end sections.  
         [0009]     The elastic sleeve segments can overlap the bending-resistant sleeve segments in their circumferential direction with lateral projections, and the projections can be connected by fusing to the bending-resistant sleeve segments. These projections increase the stiffness or strength of the connection between the sleeve segments and enhance grip of the sleeve when handling the sleeve.  
         [0010]     On the inner side of the sleeve, a stop rib providing an insertion limitation for the end sections can be arranged circumferentially; one end section rests against the stop rib with its free end and the other end section has a shoulder that rests against the stop rib. The stop rib increases additionally the transverse stiffness of the sleeve and contributes also to the seal-tightness at the connecting location.  
         [0011]     Preferably, the stop rib is comprised of rib segments that are formed as monolithic parts of the bending-resistant sleeve segments and monolithic parts of the elastic sleeve segments. At least the rib segments that are monolithic parts of the elastic sleeve segments increase as a result of their elasticity the seal-tightness of the connection.  
         [0012]     When the stop rib comprises an elastically expandable material and forms a monolithic part of the elastic sleeve segments, the stop rib increases the seal-tightness of the connection about its entire circumference.  
         [0013]     The bending-stiff sleeve segments can have recesses in their exterior side in which recesses an elastically expandable material is embedded. The elastic material embedded in the recesses enhances additionally grip on the sleeve when handling the sleeve.  
         [0014]     Also, it can be provided that the stop rib comprising an elastically expandable material is monolithically connected to the elastically expandable material in the recesses through openings provided in the bending-stiff sleeve segments. In this configuration, the stop rib and the elastic expandable material in the recesses can be produced in a single injection molding process.  
         [0015]     Alternatively, it can be provided that the sleeve is a monolithic part made from hard rubber or a reinforced and/or crosslinked elastomer. The sleeve can then also be produced in a single injection molding process and is elastic as well as sufficiently bending-resistant.  
         [0016]     Instead, it is also possible that the sleeve, including the second securing ribs, comprises an elastically expandable material, that the second securing ribs are spaced apart in the circumferential direction, and that, about the circumferential area of the second securing ribs, cylinder parts made from metal or hard-elastic plastic material and having at their circumferential edges radially inwardly projecting legs are embedded in the elastically expandable material of the sleeve in such a way that the legs project into the second securing ribs. In this configuration of the sleeve, in the area of the cylinder parts comprised of metal or hard-elastic plastic material there are also bending-resistant sleeve segments and between them there are elastic sleeve segments that enable widening of the sleeve for coupling and decoupling the end sections.  
         [0017]     In the last embodiment it can also be provided that on the inner side of the sleeve a stop rib for insertion limitation of the end sections extends circumferentially wherein the stop rib comprises the elastically expandable material of the sleeve. The stop rib is then suitable also at the same time for sealing the connecting location of the end sections.  
         [0018]     The second securing ribs of the sleeve can extend about at least 80 E and less than 180 E of the sleeve circumference.  
         [0019]     Moreover, behind the first securing ribs grooves can be provided in the circumferential direction of the end sections; the axial width of the grooves corresponds to the axial width of the first securing ribs. These grooves enable an insertion limitation of the end sections even when the sleeve has no stop rip and the end section onto which the other end section is pushed when coupling the end section has no stop shoulder. Also, the sleeve can be pre-mounted on one of the end sections in a non-slidable and captive way.  
         [0020]     Preferably, it is also provided that behind one of the first securing ribs of one end section on its end facing away from the end of this end section inserted into the sleeve two radially projecting cams are provided diametrically opposite one another relative to the longitudinal center axis of this end section, wherein the two cams project by a radial height that matches a radial height of said first securing rib. These cams enable removal of the end section provided with the cams by manually rotating the sleeve until the securing ribs of this end section of the sleeve are seated on the cams and subsequently pulling this end section out of the sleeve.  
         [0021]     In this connection, the first securing ribs should extend about the entire circumference of the end sections.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0022]     In the drawing:  
         [0023]      FIG. 1  is a perspective illustration of an embodiment of a connecting arrangement according to the invention in axial section in the coupled state;  
         [0024]      FIG. 2  shows the connecting arrangement according to  FIG. 1  in the decoupled state;  
         [0025]      FIG. 3  is a modification of a sleeve of the connecting arrangement according to  FIG. 1  in a perspective illustration;  
         [0026]      FIG. 4 a  side view of the sleeve according to  FIG. 3  on a smaller scale;  
         [0027]      FIG. 5  shows the section V-V of  FIG. 4 ;  
         [0028]      FIG. 6  shows the section VI-VI of  FIG. 5 ;  
         [0029]      FIG. 7  shows the section VII-VII of  FIG. 5 ;  
         [0030]      FIG. 8  is a perspective illustration of another modification of the sleeve according to  FIG. 1 ;  
         [0031]      FIG. 9  is a side view of the sleeve according to  FIG. 8  on a smaller scale;  
         [0032]      FIG. 10  shows the section X-X of  FIG. 9 ;  
         [0033]      FIG. 11  shows the section XI-XI of  FIG. 10 ;  
         [0034]      FIG. 12  is another side view of the sleeve according to  FIG. 8 ;  
         [0035]      FIG. 13  is a perspective view of another modification of the sleeve according to  FIG. 1 ;  
         [0036]      FIG. 14  is an axial view of the sleeve according to  FIG. 13 ;  
         [0037]      FIG. 15  shows the section XV-XV of  FIG. 14 ;  
         [0038]      FIG. 16  shows the section XVI-XVI of  FIG. 14 ;  
         [0039]      FIG. 17  is a perspective view of another modification of sleeve according to  FIG. 1 ;  
         [0040]      FIG. 18  is a side view of the sleeve according to  FIG. 17  on a smaller scale; and  
         [0041]      FIG. 19  shows the section IXX-IXX of  FIG. 18 .  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0042]     The connecting arrangement according to  FIG. 1  and  FIG. 2  is comprised of two fluid conduits  1  and  2  (the illustrated embodiment shows conduits in the form of hoses) with end sections  3  and  4 ; two union nuts  5 ,  6  connecting the fluid conduits  1 ,  2  with one of the end sections  3 ,  4 , respectively; a coupling element in the form of a circumferentially closed circular cylindrical sleeve  7 ; and a sealing ring  8 . All parts are comprised of plastic material. However, the end sections  3 ,  4  and the union nuts  5 ,  6  can also be made from metal. Instead of connecting the end sections  3 ,  4  and the fluid conduits  1 ,  2  to one another by union nuts  5 ,  6 , these parts can also be configured as monolithic parts made of plastic material. Moreover, at least one of the two end sections  3 ,  4  can be a pipe socket, for example, the pipe socket connector of a radiator of a motor vehicle that is then connected to a cooling water line in the form of a cooling coil in the interior of the radiator. In this case, the corresponding end section would however be made from metal.  
         [0043]     The sleeve  7  is comprised of two sleeve segments that are diametrically opposed to one another relative to the longitudinal center axis of the sleeve and made from hard-elastic thermoplastic material, for example, one of the plastic materials polypropylene (PP), polyethylene (PE), polyamide (PA), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphenylene amide (PPA), and thermosetting plastic material so that the sleeve segments  9  are bending-resistant. Inserts  10  of elastomer material are injection-molded into the outer side of the sleeve segments  9 . The inserts  10  are provided with recesses  11  in order to enhance grip on the sleeve  7 . However, the inserts are not mandatory. Instead, the sleeve segments  9  can be corrugated on the outer side. Between the sleeve segments  9  and the inserts  10 , elastic sleeve segments  12  made from thermoplastic elastically expandable material can be injection-molded onto the sleeve segments  9  and their inserts  10  so that the sleeve segments  9  and their inserts  10  are connected to the sleeve segments  12  by being fused thereto and the sleeve  7  can be radially widened. The thermoplastic elastically expandable material of the sleeve segments  12  is, for example, one of the plastic materials of thermoplastic elastomer (TPE), vulcanized thermoplastic elastomer (TPV), thermoplastic polyurethane (TPU), thermoplastic ether ester elastomer (TEEE), ethylene propylene rubber (EPDM), fluorinated rubber (FKM), fluorosilicone, liquid silicone rubber (LSR), and ethylene vinyl acetate (EVA). The sleeve segments  9  extend therefore across a circumferential area of the sleeve  7  of less than 180 E but more than 80 E, preferably about an area of approximately 140 E and 160 E.  
         [0044]     The bending-resistant sleeve segments  9  are provided on their inner side in the vicinity of their ends with securing ribs  13  extending in the circumferential direction and provided on their circumferential ends with slanted flanks  14  ( FIG. 2 ).  
         [0045]     The elastic sleeve segments  12  are provided externally with an axially extending projection  15  that has centrally a circular arc shaped double arrow  16  indicating the rotatability of the sleeve  7 .  
         [0046]     The interior of the sleeve  7  at its axial center is provided with a circumferentially extending stop rib  17  ( FIG. 1 ) whose segments are identified in the area of the elastic sleeve segments  12  by reference numeral  17   a  and in the area of the hard-elastic sleeve segments  9  by reference numeral  17   b.  The stop rib segments  17   a  are comprised therefore of the same material as the elastic sleeve segments  12  and the stop rib segments  17   b  are comprised of the same material as the hard-elastic sleeve segments  9 .  
         [0047]     The end sections  3 ,  4  are provided with circumferentially extending securing ribs  18  about their circumference. For connecting the fluid conduits  1 ,  2 , the end sections  3 ,  4  are inserted axially into the sleeve  7  and coupled after the sealing ring  8  has been inserted into an annular groove of the end section  3  that is inserted into the end section  4 . Upon insertion of the end sections  3 ,  4  into the sleeve  7  in a predetermined relative angular position relative to the end section  4 , the sleeve  7  is radially elastically widened as the securing ribs  13  of the sleeve  7  pass across the securing ribs  18  of the end sections  3 ,  4  until the securing ribs  13  of the sleeve  7  lock behind the securing ribs  18  of the end sections  3 ,  4  in a groove  19  or  20  adjoining the securing ribs  18  and extending in the circumferentially direction, respectively. At the same time, the end sections  3 ,  4  come to rest against the stop rib  17 . In order to enable contact of the end section  3  at the stop rib  17 , the end section  3  is provided with a shoulder  21 . The groove  19  in the end section  3  is a circumferential annular groove. In contrast, the groove  20  in the end section  4  does not extend completely about the circumference but is interrupted by two cams  22  that project by a radial height matching the radial height of the securing rib  18  of the end section  4 . The two cams  22  are positioned diametrically opposed to one another relative to the longitudinal center axis of the end section  4  and are provided with slanted flanks. The axial width of the securing ribs  13  of the sleeve  7  corresponds to the axial width of the grooves  19  and  20 . Upon insertion of the end sections  3 ,  4  into the sleeve  7 , the securing ribs  13  of the sleeve  7  can therefore also contact the flanges  23 ,  24  delimiting the grooves  19  and  20  of the end sections  3 ,  4 , respectively. In the coupled state of the connecting arrangement according to  FIG. 1 , the sleeve segments  12  rest with their ends against the cams  23 . For releasing the connection, the sleeve  7  is rotated. When doing so, the securing ribs  13  move with their slanted flanks  14  onto correspondingly slanted flanks of the cams  22  at one end of the bending-resistant sleeve segments  9  and widen the sleeve  7 . In this rotational angle position, the sleeve  7  together with the end section  3  and the flexible fluid conduit  1  can be removed from the end section  4 .  
         [0048]     The sleeve  7  can also be pre-mounted on the end section  3  in the position illustrated in  FIG. 1  and, finally, can be coupled with the end section  4  and the fluid conduit  2  connected thereto in an angular position in which the elastic sleeve segments  12  are aligned with the cams  25  in order to connect the fluid conduits  1 ,  2  with one another. The stop rib  17  not only provides a limitation for the insertion depth of the end sections  3 ,  4  into the sleeve  7  but also a sealing action at the connecting location of the end sections  3 ,  4  in addition to the sealing action of the sealing ring  8 .  
         [0049]     The flanges  23 ,  24  are provided with ribs so that they provide enhanced grip in order to be able to hold the end sections  3 ,  4  safely when rotating the sleeve  7 .  
         [0050]     FIGS.  3  to  7  represent a sleeve  27  that is modified somewhat relative to the sleeve  7  according to  FIG. 1  and  FIG. 2 . The parts of the sleeve  27  that resemble those of the sleeve  7  are identified by reference numerals increased by 20 relative to the corresponding parts of the sleeve  7 ; the same parts have the same reference numerals.  
         [0051]     A circumferentially extending stop rib  37  of the same thermoplastic elastic material as that used for the elastic sleeve segments  32  is injection-molded onto the inner side of the bending-resistant sleeve segments  9  and the elastic sleeve segments  32 . At the same time, the elastic material of the stop rib  37  is injection-molded through openings  30  provided in the bending-resistant sleeve segments  29  into recesses  31  provided in the bending-resistant sleeve segments  29  so that the exterior side of the sleeve segments  29  provide grip-enhancing surfaces  23  for facilitating manual rotation of the sleeve  27 .  
         [0052]     The circumferentially extending elastic stop rib  37  has the advantage that it better seals the connecting location of the end sections  3 ,  4  than the sections of the stop rib  17  provided in the area of the bending resistant sleeve segments  9  of the sleeve  7  and made of the same harder material as the sleeve segments  9 ; the stop rib  17  is comprised only in the area of the elastic sleeve segments  12  of the same elastic material as the sleeve segments  12 .  
         [0053]     FIGS.  8  to  12  show a sleeve  47  that is another modification of the sleeve  7  according to  FIGS. 1 and 2 . The parts of the sleeve  47  that resemble those of the sleeve  7  are identified by reference numerals increased by 30 relative to the corresponding parts of sleeve  7 ; the same parts have the same reference numerals.  
         [0054]     In deviation from the sleeve  7  according to  FIGS. 1 and 2 , the elastic sleeve segments  42  are provided with lateral projections  43  that are injection-molded into recesses of the hard-elastic sleeve segments  39  and are fused to the sleeve segments  39 . The projections  43  increase the strength of the connection of the elastic sleeve segments  42  with the hard-elastic sleeve segments  39 . The projection  15  of elastic sleeve segments  12  of the sleeve  7  according to  FIGS. 1 and 2  has been omitted because the elastic material of the sleeve segments  42  can be selected such that it enhances grip sufficiently. For example, silicone rubber can be used.  
         [0055]     In FIGS.  13  to  16  a sleeve  57  modified relative to sleeve  7  according to  FIG. 1  and  FIG. 2  is illustrated. The parts of the sleeve  57  that resemble those of the sleeve  7  are identified by reference numerals increased by 50 relative to the corresponding parts of sleeve  7 ; the same parts have the same reference numerals.  
         [0056]     Sleeve  57  is comprised about its entire circumference of a monolithic part of hard-elastic material, for example, hard rubber or reinforced and/or vulcanized thermoplastic elastomer. The securing ribs  18  of the sleeve segments  9  (the latter are monolithic parts of the sleeve segments  12 ) extends across approximately 80 E to 100 E in the circumferentially direction of the sleeve  57 , preferably about approximately 90 E. Accordingly, the sleeve segments  9  are less elastically expandable then the thinner sleeve segments  12  so that the sleeve  57  can still be expanded or widened. In addition to the projection  15 , the sleeve  57  is provided with axial ribs  56  that are distributed about the circumference in order to enhance grip on the sleeve  57 .  
         [0057]     FIGS.  17  to  19  represent another sleeve  67  as a modification of the sleeve  7  according to  FIG. 1  and  FIG. 2 . The parts of the sleeve  67  that resemble those of the sleeve  7  are identified by reference numerals increased by 60 relative to the corresponding parts of sleeve  7 ; the same parts have the same reference numerals.  
         [0058]     The sleeve  67 , including its securing ribs  13  and stop rib  17  has about its entire circumference the same elastically expandable material as the sleeve segments  12  of the sleeve  7  according to  FIGS. 1 and 2 . In the circumferential area of the securing ribs  13 , however, a cylindrical part  68  made of metal or the same hard-elastic plastic material as the sleeve segments  9  according to  FIG. 1  and  FIG. 2  is embedded. The cylinder parts  68  have at their circumferential edges inwardly projecting legs  69  that project into the securing rib  73 . The legs  69  can also be interrupted in the circumferential direction.  
         [0059]     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.