Patent Publication Number: US-2023163545-A1

Title: Connecting device

Description:
INCORPORATION BY REFERENCE 
     The following documents are incorporated herein by reference as if fully set forth: German Patent Application No. 10 2021 130 901.8, filed Nov. 25, 2021. 
     TECHNICAL FIELD 
     The present invention relates to a connecting device used for synchrotrons or other particle accelerators for passing through charged particles. 
     BACKGROUND 
     Connecting devices of this type are used in so-called synchrotrons or other particle accelerators. These synchrotrons or particle accelerators have a line system consisting of lines and/or chambers through which electrically charged particles are passed, usually in the form of electrically charged particle beams. In such line systems, connecting devices of the type in question serve to compensate for displacements and changes in length caused by thermal or other factors so that excessive stresses or distortion do not occur in the line system. For this purpose, such connecting devices are designed to be flexible so that the first flange and the second flange can move relative to each other in the longitudinal direction of the connecting device and also in at least one transverse direction angled relative to the longitudinal direction, in order to compensate for the displacements and/or changes in length in the line system caused, for example, by thermal factors. 
     In addition, it is also important that the electrically charged particles or the beam of electrically charged particles that also pass through the connecting device or through the line cavity of the line element are not deflected or negatively influenced in any other way. 
     A connecting device of the type in question is shown in FIG. 1 of US 2017/0279205 A1. The connecting devices shown in FIGS. 2 to 4 of US 2017/0279205 A1 are not devices of the type in question. Their flanges are not connected to each other with the interposition of a bellows. 
     SUMMARY 
     It is the object of the invention to improve connecting devices of the type in question in such a way that they can compensate well for displacements in the longitudinal and transverse directions of the connecting device and at the same time the charged particles passed through the line cavity are deflected as little as possible or are not deflected or otherwise negatively influenced during this relative displacement of the flanges with respect to each other. 
     This is achieved by a connecting device having one or more of the features disclosed herein. 
     In the invention, it is thus provided that a connection element is arranged on the first flange and on the second flange in each case for electrically connecting the line element to the flange in question, the line element being movably mounted in or on both connection elements, and/or the line element having or consisting of at least one annular spring or at least one helical spring. 
     The line element according to the invention ensures that the cross-sectional area of the line cavity arranged inside the line element remains as constant as possible in the event of a relative displacement of the flanges of the connecting device relative to one another caused by thermal or any other factors. This, in combination with the bellows guided around the outside of the line element, ensures that the charged particles passed through the line cavity of the connecting device are not deflected or otherwise negatively influenced, or at least only minimally. The invention ensures that the flanges remain optimally electrically conductively connected to each other via their connection elements and the line element even in the event of larger displacements of the flanges in the longitudinal direction of the connecting device and/or in the transverse direction thereof. This is achieved by the movable mounting of the line element in or on both connection elements and/or simply by the fact that the line element is formed as an annular spring or helical spring or at least has such a spring. 
     In case of doubt, the terms “longitudinal direction” and “transverse direction” of the connecting device refer to the initial position of the connecting device in which the two flanges of the connecting device are not displaced relative to each other by external forces. The transverse direction(s) is/are angled to the longitudinal direction. Preferably, the transverse direction(s) run orthogonal to the longitudinal direction. 
     Connecting devices according to the invention are preferably used in line systems of synchrotrons or other particle accelerators. These line systems can, as is known per se, comprise lines but also chambers. 
     In connecting devices according to the invention, the first flange and the second flange are connected to each other with the interposition of the bellows. There are different variants for this. The bellows can extend over the entire distance between the first flange and the second flange and thus directly connect the first flange and the second flange to each other. However, it is also possible that the bellows only extends over a partial region between the first flange and the second flange. In these exemplary embodiments, a jacket tube is advantageously arranged at least on at least one of the flanges. The bellows can then extend, for example, from a free end of the jacket tube to the other flange. A second jacket tube can be arranged around the bellows and is then preferably arranged or fixed or formed on the other flange. In any case, the bellows is advantageously made of metal. 
     Since the connecting device according to the invention serves to compensate for length changes and/or displacements in a line system, in particular those caused by thermal factors, it could also be referred to as a compensation device or a compensation connecting device. 
     In order to be able to compensate not only for displacements of the line system in the longitudinal and/or transverse direction of the connecting device, but also for torsional movements in the line system, particularly preferred variants of the invention provide that at least one of the connection elements is rotatably mounted on the flange on which it is arranged, preferably rotatably about an axis of rotation coaxial or at least parallel to the longitudinal direction of the connecting device. 
     The line element that surrounds the line cavity can be formed to be circumferentially closed. However, this is not absolutely necessary. Rather, it is important that the line element connects the connection elements and thus the two flanges of the connecting device to each other so as to produce a good electrically conductive connection. For this purpose, it can also be provided that the line element comprises a plurality of rods, the rods being arranged running parallel to each other and spaced apart from each other and jointly surrounding a partial region of the line cavity or the entire line cavity. The line element can also consist exclusively of such an arrangement of rods. 
     In order to be able to compensate for displacements of the flanges in the longitudinal and/or transverse direction of the connecting device and at the same time ensure optimum electrical contact, it is preferably provided that the rods are mounted movably and electrically conductively in or on both connection elements. In this context, it is particularly preferred that the rods are mounted movably and electrically conductively in rod-receiving cavities of the two connection elements. In the latter variants, the rods are preferably movably mounted with their ends in the rod-receiving cavities. There, they are surrounded on all sides by the corresponding walls of the connection element, so that the rods cannot lift off from the connection element, but rather a very good electrical contact is always ensured between each rod and the corresponding connection element. Preferably, the rods each have a circular cross-section. This is also very favourable in terms of ensuring optimum electrical contact. Alternative variants, however, also provide for the rods to be formed as flattened rods. 
     It can also be provided that two bulges, spaced apart from one another in the longitudinal direction of the connecting device, are formed on rods of the connection element in question for electrically conductive connection to one rod each of the line element, the rods with the bulges resting in an electrically conductive manner on the particular rod of the line element and the particular rod of the line element being supported by a support shoulder of the connecting device in a region between the two bulges on the side opposite the particular rod of the particular connection element. The at least two bulges arranged one behind the other in the longitudinal direction of the connecting device and the support shoulder arranged between them in the longitudinal direction ensure particularly good electrical contact between the rods of the line element and the corresponding connection element even if there are larger displacements in the longitudinal and/or transverse directions of the connecting device. 
     Another variant for achieving precisely this provides that the ends of the rods of the line element facing the connection element in question each have a bend and the connection element in question has rods with bends, the bends of the rods of the connection element in question being arranged in intermediate spaces between the bends of the rods of the line element and a connecting rod being passed through the bends of the rods of the particular connection element and through the bends of the rods of the line element. It is advantageous here if the various bends of the rods are in the form of slots extending in the longitudinal direction of the connecting device. This ensures that the connecting rod is mounted in the bends so that it is displaceable in the longitudinal direction. 
     In the variants in which the line element has an annular spring or is formed as such, it is advantageously provided that the annular spring has a sequence of ring elements arranged one behind the other, the successive ring elements being connected to one another by means of elastic elements and being movable relative to one another. The ring elements can preferably be rigid bodies in themselves. Advantageously, all ring elements have the same diameter. However, this does not necessarily have to be so. In any case, the elastic elements mounted between the ring elements ensure a corresponding movability of the annular spring in order to be able to compensate for an offset between the flanges in the longitudinal and/or transverse direction of the connecting device. Here, too, the ring elements ensure that the line element has the same line cross-section everywhere, even in a relatively strongly deflected state. In addition to the elastic elements, which can be formed as a helical spring, for example, electrical sliding contacts can also be arranged between the ring elements and ensure an optimal electrically conductive connection of the successive ring elements to each other and an optimal electrically conductive transition from the line element to the corresponding connection element. 
     In variants of the invention in which a helical spring is part of or forms a line element, it is advantageously provided that the helical spring has a plurality of turns arranged one behind the other, which are elastically movable relative to each other. This also ensures that the line cavity within the line element has the same cross-section everywhere, even in the case of larger relative displacements of the flanges in the longitudinal and/or transverse direction of the connection element. In the undeflected state of the connecting device, the turns are advantageously arranged on an imaginary circular-cylinder lateral surface. Particularly preferred variants provide that the line element has two helical springs or consists of these, one of the helical springs being arranged in an interior space of the other helical spring, it preferably being provided that the turns of the two helical springs are arranged offset with respect to one another in the longitudinal direction of the connecting device. 
     Connecting devices according to the invention are advantageously designed so that a negative pressure or vacuum in the region of 1×10 10  mbar (millibar) and smaller can be formed in the interior space surrounded by the bellows. 
     Particularly preferred variants of the invention provide that the flanges, the connection elements and/or the line element consist of or comprise a copper-beryllium alloy. Alternative materials are stainless steel or copper, which are preferably silver-plated or gold-plated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and details of the invention, as well as preferred variants thereof, are explained below by way of example in the description of the figures, in which: 
         FIGS.  1  to  4    show illustrations of a first exemplary embodiment of a connecting device according to the invention; 
         FIGS.  5  to  8    show illustrations of a second exemplary embodiment of a connecting device according to the invention; 
         FIGS.  9  to  12    show illustrations of a third embodiment of a connecting device according to the invention; 
         FIGS.  13  to  16    show illustrations of a fourth embodiment of a connecting device according to the invention; 
         FIGS.  17  to  20    show illustrations of a fifth embodiment of a connecting device according to the invention, and 
         FIGS.  21  to  24    show illustrations of a sixth embodiment of a connecting device according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The first exemplary embodiment according to the invention of a connecting device  1  shown in  FIGS.  1  to  4    is explained below firstly.  FIG.  1    shows a longitudinal section through the connecting device  1  according to the invention.  FIG.  2    shows the region A from  FIG.  1    enlarged.  FIG.  3    shows a perspective view of the connecting device  1  and  FIG.  4    shows the region B from  FIG.  3    enlarged. 
     Before discussing the special embodiment of the line element  10  and its connection to the connection elements  13  and  14  in this exemplary embodiment, features of this embodiment as also realized in the subsequent exemplary embodiments are discussed. This part of the description thus applies to all embodiments shown here. 
     In all exemplary embodiments, this connecting device is a connecting device  1  for a line system of a synchrotron or another particle accelerator. Electrically charged particles, usually in the form of a beam of electrically charged particles, are thus passed through this line system as well as through the connecting device  1 . The line system can comprise both lines and chambers. In any case, the connecting device  1  comprises a first flange  2  and a second flange  4  as well as a bellows  6 . The first flange  2  and the second flange  4  are connected to each other with the interposition of the bellows  6 . In this exemplary embodiment, this is realized in such a way that the bellows  6  extends only over a partial region of the connection between the two flanges  2  and  4 . Specifically, in this exemplary embodiment, as in the other exemplary embodiments, it is arranged between the pivot bearing ring  32  of the second flange  4  and a jacket tube  40 , which is fixed to the first flange  2 . In alternative embodiments, however, the bellows  6  could, for example, also extend completely from the first flange  2  to the second flange  4 . In  FIG.  1   , lines  3  and  5  of the line system are indicated by dashed lines. The first flange  2  is connected to the first line  3  and the second flange  4  to the second line  5 . Instead of lines  3  or  5 , chambers of the line system could of course also be connected to one of the flanges  2  and  4  or to both flanges  2  and  4  accordingly. In any case, the connecting device  1  is arranged between the lines  3  and  5  or chambers of the line system in such a way that the line interior  33  of the particular line or a corresponding chamber interior space is aligned with the line cavity  11  of the line element  10  and is in communication, so that electrically charged particles passed through the line interior  33  and in particular a corresponding beam of electrically charged particles is also passed correspondingly through the line cavity  11  of the line element  10 . 
     The connecting device  1  of all exemplary embodiments shown here serves to compensate for displacements between the first line  3  or chamber of the line system and the second line  5  or chamber of the line system. These displacements can occur both in the longitudinal direction  7  of the connecting device  1  and in at least one transverse direction  8  of the connecting device  1 , which is angled with respect to the longitudinal direction and is preferably orthogonal. The flanges  2  and  4  of the connecting device  1  can be moved along with their respective lines  3  and  5  or chamber to which they are attached. The bellows  6  and the corresponding line element  10  allow this relative movement of the flanges  2  and  4  both in the longitudinal direction  7  and in the transverse direction(s)  8 , so that no stresses or breaks occur in the line system. These displacements in the longitudinal direction  7  and/or transverse direction  8  in the line system can be caused by thermal, but also other factors. 
     All line elements  10  realized in the exemplary embodiments shown here have the advantage that they can compensate for corresponding relative movements between the flanges  2  and  4  without the risk of their electrically conductive connection to the connection elements  13  and  14  and thus between the flanges  2  and  4  being interrupted. In addition, the line elements  10  have the advantage that they always ensure that the opening cross-section of the line cavity  11  surrounded by the line element  10  remains at least substantially unchanged during these relative displacements of the flanges  2  and  4  with respect to each other. This ensures that the particles passed through the line cavity  11  are not deflected and thus the particle beam remains undisturbed. 
     In all exemplary embodiments, it is in any case the case that the line element  10  is arranged in the interior space  9  surrounded at least in regions by the bellows  6 , the line elements  10  of the various exemplary embodiments electrically conductively connecting the flanges  2  and  4  to one another via the connection elements  13  and  14 . The interior space of the line element  10  forms the line cavity  11  through which the charged particles are passed. 
     In all exemplary embodiments shown here, a jacket tube  41  is arranged on the second flange  4 . This surrounds the bellows  6  as well as the jacket tube arranged on the first flange  2 . However, as already explained above, this can also be solved differently. 
     In order to be able to compensate not only for relative displacements in the line system in the longitudinal direction  7  and in the transverse direction  8 , but also to be able to compensate for torsional movements in the line system, it is provided in all variants shown here that at least one of the connection elements  13  or  14  is rotatably mounted on the corresponding flange  2  or  4  on which it is arranged. Specifically, this is realized in the exemplary embodiments shown here by the pivot bearing ring  32 , to which the connection element  14  is fixed. This pivot bearing ring  32  is rotatably mounted in the second flange  4 . The axis of rotation  17  about which the pivot bearing ring  32  is rotatable runs coaxially or at least parallel to the longitudinal direction  7 . 
     In all exemplary embodiments, it is in any case the case that connection elements  13  and  14  are arranged one on the first flange  2  and one on the second flange  4 , for electrically connecting the line element  10  to the flanges  2  and  4 . 
     In the first exemplary embodiment shown in  FIGS.  1  to  4   , when relative movement occurs between the flanges  2  and  4 , electrical contact between the line element  10  and the two connection elements  13  to  14  is ensured by the line element  10  being movably mounted in or on both connection elements  13  and  14 . 
     The line element  10  has a plurality of rods  18 . The rods  18  run parallel to each other and are spaced apart from each other in the circumferential direction. Together, they surround at least a partial region of the line cavity  11 . In this first exemplary embodiment, the rods  18  of the line element  10  are connected to each other in the central region of the line element in a connecting region  31 . 
     In this first exemplary embodiment, rods  23  are also formed on the various connection elements  13  and  14 . The rods  23  of the connection element  13  are pushed into the line element  10  on one side. The rods  23  of the other connection element  14  are pushed into the line element  10  on the opposite side. For the electrically conductive connection of one rod  23  of each of the connection elements  13  and  14  to one rod  18  of the line element  10 , in this exemplary embodiment two bulges  19  and  20  are formed on the particular rod  23  of the particular connection element  13  and  14  and are spaced apart from one another in the longitudinal direction  7  of the connecting device  1 . These bulges can be seen particularly well in the enlargement of the region A from  FIG.  1    in  FIG.  2   . The rod  23  in question rests with its bulges  19  and  20  on the rod  18  in question of the line element  10  in an electrically conductive manner. In the region between the two bulges  19  and  20 , the rods  18  of the line element  10  are each supported on the side opposite the rod  23  in question by a support shoulder  21  of the connecting device  1 . In  FIG.  2   , as well as in the perspective view in  FIG.  4   , it can be clearly seen how the rods  18  of the line element  10  are guided through between the particular support shoulder  21  on one side and the rods  23  of the particular connection element  13  or  14  with the bulges  19  and  20  on the other side. If there is now a relative movement of the two flanges  2  and  4  in the longitudinal direction  7  and/or in the transverse directions  8 , the interaction of the bulges  19  and  20  with the support shoulder  21  in question ensures that the line element  10  with its rods  18  always remains in optimum electrical contact with the connection elements  13  and  14  or their rods  23 . This also ensures the electrically conductive connection between the flanges  2  and  4 . The rods  18  of the line element  10  as well as the rods  23  of the connection elements  13  and  14  are correspondingly elastic in order to allow these movements of the flanges  2  and  4  relative to each other. The described type of connection between the line element  10  and the connection element  14  is the same as between the line element  10  and the connection element  13 . This is again the case in all exemplary embodiments. 
     Looking now at the second exemplary embodiment of the invention in  FIGS.  5  to  8   ,  FIG.  5    in turn shows a corresponding longitudinal section.  FIG.  6    shows the region C from  FIG.  5    enlarged.  FIG.  7    shows this second exemplary embodiment of the connecting device  1  from  FIG.  5    in a perspective, longitudinal sectional view.  FIG.  8    shows the region D from  FIG.  7    enlarged. In the following, fundamentally only the differences from the first exemplary embodiment will be discussed. Otherwise, reference is made to the previous explanations. 
     A common feature with the first exemplary embodiment is first of all that here, too, the line element  10  has a plurality of rods  18  which run parallel to one another and are arranged at a distance from one another and together surround the line cavity  11  between the connection elements  13  and  14 . In contrast to the first exemplary embodiment, however, the rods  18  of the line element  10  are not connected to one another in a connecting region  31 . Rather, their arrangement results from their connection to the connection elements  13  and  14 . 
     In this second exemplary embodiment of the invention according to  FIGS.  5  to  8   , the rods  18  each have a circular cross-section. This can be seen particularly well in  FIG.  8   . The rods  18  are each mounted movably and electrically conductively in both connection elements  13  and  14 . Specifically, in this exemplary embodiment, it is provided that the rods  18  are each arranged with their respective end regions in rod-receiving cavities  34  of the two connection elements  13  and  14 . This can be seen clearly in  FIG.  6    and in  FIG.  8   . The rods  18  are mounted in the respective rod-receiving cavities  34  so as to be displaceable in the longitudinal direction. The walls of the connection element  13  and  14  surrounding the rod receiving cavities  34 , however, always ensure a safe electrical contact between the rods  18  and thus the line element  10  and the particular connection element  13  or  14 , even with a corresponding relative displacement of the two flanges  2  and  3  in the transverse direction  8 , since the rods  18  are in contact with the particular connection element  13  or  14  over their entire circumference in the rod receiving cavity  34 . 
     The third exemplary embodiment of the invention shown in  FIGS.  9  to  12    is very similar to the already described second exemplary embodiment of the invention according to  FIGS.  5  to  8   . The only difference from the second exemplary embodiment is that the rods  18  of the line element  10  do not have a circular cross-section here, but are formed as flattened rods  18 .  FIG.  9    in turn shows a longitudinal section in this embodiment,  FIG.  10    shows the region E from  FIG.  9    enlarged.  FIG.  11    shows a perspective view of a corresponding longitudinal section through the connecting device  1 , and  FIG.  12    shows the region F from  FIG.  11    enlarged.  FIG.  12    shows particularly well the design as flattened rods  18 , which are mounted in corresponding rod receiving cavities  34  of the two connection elements  13  and  14 . 
       FIGS.  13  to  16    show illustrations of a fourth exemplary embodiment of the invention. In this example, the line element  10  is formed as an annular spring  15 . In other words, it could also be said that the line element  10  consists of an annular spring  15 . Of course, it would also be possible for the line element  10  to have such an annular spring  15  only in certain regions and otherwise to have a different design. 
       FIG.  13    shows a longitudinal section through the connecting device  1 .  FIG.  14    shows the region G from  FIG.  13    enlarged.  FIG.  15    in turn shows a longitudinal section through a corresponding perspective view of this connecting device  1 .  FIG.  16    shows the region H from  FIG.  15    enlarged. 
     The annular spring  15  has a sequence of ring elements  27  arranged one behind the other. These ring elements  27  can be substantially rigid in themselves. The successive ring elements  27  are connected to each other by means of elastic elements  28  and can thus be moved relative to each other. The specific structure realized here can be seen particularly well in  FIGS.  14  and  16   . There it can be seen that in this exemplary embodiment the elastic elements  28  are formed as helical springs. Of course, other suitable types of springs or elastic bodies could also be used. In any case, the elastic elements  28  allow a relative movement of the ring elements  27  both in the longitudinal direction  7  and in the transverse direction  8 . The elastic elements  28  also ensure a corresponding resetting when the forces acting on the flanges  2  and  4  from the outside are no longer present. In the specific exemplary embodiment shown here, intermediate ring elements  38  and additionally electrical sliding contacts  39  are located between two adjacent ring elements  27 . The electrical sliding contacts  39  are of a correspondingly flexible design and ensure reliable electrical contact between the successive ring elements  27 . Corresponding ends of the elastic elements  28  are mounted in the intermediate ring elements  38 , as can be clearly seen in  FIGS.  14  and  16   . Also in this exemplary embodiment, this particular design of the line element  10  ensures that in case of relative displacements of the flanges  2  and  4  in longitudinal direction  7  or transverse direction  8 , a narrowing of the cross-sectional area of the line cavity  11  does not occur. Thus, this type of line element  10  according to the invention also ensures that a relative displacement between the two flanges  2  and  4  does not negatively influence the charged particles or beams of such charged particles passed through the line cavity  11 . 
     The fifth exemplary embodiment of the invention shown in  FIGS.  17  to  20    is a variant in which the line element  10  is formed from at least one helical spring  16 .  FIG.  17    in turn shows a longitudinal section through the connecting device  1 . In  FIG.  18   , the region I is shown enlarged.  FIG.  19    shows a perspective view in longitudinal section and  FIG.  20    shows the region J from  FIG.  19   . Even though in principle a single helical spring  16  would be sufficient to electrically conductively connect the two connection elements  13  and  14  to each other and to surround the line cavity  11 , in this exemplary embodiment it is nevertheless provided that the line element  10  has two helical springs  12  and  16 , one of the helical springs  12  being arranged in an interior space  30  of the other helical spring  16 . The turns  29  of the two helical springs  12  and  16  are arranged offset from one another in the longitudinal direction  7  of the connecting device  1 , as can also be seen clearly in  FIGS.  18  and  20   . The turns  29  of both helical springs  12  and  16  each lie on an imaginary circular-cylinder lateral surface. The helical springs  12  and  16  or their turns  29  allow a corresponding elastic deformation of the line element  10  in the event of a corresponding relative displacement between the flanges  2  and  4 , without the opening cross-section of the line cavity  11  changing significantly. This also ensures that the charged particles or beams of charged particles passing through the line cavity  11  are not negatively affected. The turns  29  can be moved elastically relative to each other, so that a corresponding resetting is also ensured when the displacement between the flanges  2  and  4  is cancelled. 
     The sixth exemplary embodiment in  FIGS.  21  to  24    now shows a variant of a line element  10  in which the ends of the rods  18  of the line element  10  pointing towards the corresponding connection element  13  or  14  each have a bend  22 .  FIG.  21    in turn shows a longitudinal section, and  FIG.  22    shows the region K from  FIG.  21    enlarged.  FIG.  23    shows a perspective longitudinal section.  FIG.  24    shows the region L from  FIG.  23    enlarged. 
     In this exemplary embodiment, the connecting region  31  of the rods  18  is relatively wide in the central region of the line element  10 . Of course, this does not necessarily have to be the case. It could of course also be narrower, as is the case, for example, in the first exemplary embodiment in  FIGS.  1  to  4   . 
     In this exemplary embodiment, the various connection elements  13  and  14  also have rods  23 . These rods  23  also have a bend  24 . The bends  24  of the rods  23  of the particular connection element  13  or  14  are arranged in intermediate spaces  25  between the bends  20  of the rods  18  of the line element  10 . A connecting rod  26  is passed through the bends  24  of the rods  23  of the particular connection element  13  and  14  and through the bends  22  of the rods  18  of the line element  10 , as can be clearly seen in  FIGS.  22  and  24   . Both the bends  22  of the rods  18  and the bends  24  of the rods  23  are each formed as a slot, so that the various connecting rods  26  are mounted so as to be displaceable in the longitudinal direction  7  in the bends  22  and  24 . This also allows compensation for relative movements of the two flanges  2  and  4  both in the longitudinal direction  7  and in the transverse direction  8 , without this leading to relevant changes in the opening cross-section of the line cavity  11 . Also as a result of this, the course of the charged particles or beams of such particles passed through the line cavity  11  remains substantially unaffected when the flanges  2  and  4  are moved relative to each other, for example due to thermal factors, with the line system. 
     KEY TO THE REFERENCE SIGNS 
     
         
         
           
               1  connecting device 
               2  first flange 
               3  first line 
               4  second flange 
               5  second line 
               6  bellows 
               7  longitudinal direction 
               8  transverse direction 
               9  interior space 
               10  line element 
               11  line cavity 
               12  helical spring 
               13  connection element 
               14  connection element 
               15  annular spring 
               16  helical spring 
               17  axis of rotation 
               18  rod 
               19  bulge 
               20  bulge 
               21  support shoulder 
               22  bend 
               23  rod 
               24  bend 
               25  intermediate space 
               26  connecting rod 
               27  ring element 
               28  elastic element 
               29  turn 
               30  interior space 
               31  connecting region 
               32  pivot bearing ring 
               33  line interior space 
               34  rod receptacle 
               38  intermediate ring element 
               39  electrical sliding contact 
               40  jacket tube 
               41  jacket tube