Abstract:
The invention is an inner seal collar for inserting into pipes in order to seal leakage points in said pipes, comprising an expandable strip which is bent into the shape of a ring and which is preferably made of steel sheet, parts of said strip at least partly overlapping in the circumferential direction, and comprising a locking device which has at least two parallel rows of teeth, wherein a separate clamping pinion engages into at least two of the rows of teeth. The invention comprises a separate blocking pinion paired with each of the at least two clamping pinions, said blocking pinion pushing against the corresponding clamping pinion via a respective spring element and being engaged with said clamping pinion, and each of the blocking pinions is also engaged with the corresponding row of teeth.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims priority to International Patent Application PCT/EP2013/074424, filed on Nov. 21, 2013, and thereby to German Patent Application 10 2012 111 341.6, filed on Nov. 23, 2012 and German Patent Application 20 2012 012 667.9, also filed on Nov. 23, 2012. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    No federal government funds were used in researching or developing this invention. 
       NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not applicable. 
       SEQUENCE LISTING INCLUDED AND INCORPORATED BY REFERENCE HEREIN 
       [0004]    Not applicable. 
       BACKGROUND 
       [0005]    1. Field of the Invention 
         [0006]    The invention relates to an inner seal collar with improved locking mechanism for insertion into pipes, for the purpose of sealing leak points in the same. 
         [0007]    2. Background of the Invention 
         [0008]    Such internal sealing collars have been known for a long time, and are described by way of example in DE 44 01 318 C2. Using such internal sealing collars, it is possible to repair leakage points in, for example, underground pipes made of concrete or another material, without trenching. For this purpose, the internal sealing collar is inserted into the leaking pipe being repaired, up to the position of the leak. In this process, the internal sealing collar is initially spirally compressed such that it has a smaller diameter than the pipe being sealed. Once the internal sealing collar has been moved into the position of the leak in the pipe being repaired, the internal sealing collar is expanded by means of a mechanical installation device until it has come into very tight contact with the inner wall of the pipe, compressing the seal rings. The internal sealing collar is held in its expanded position by means of an arresting device which has a tensioning pinion which meshes with a toothed bar, and a spring-loading locking pinion which engages with the same. 
         [0009]    EP 0 805 932 B1 suggests an arresting device which is improved over the above. The document discloses an internal sealing collar having an arresting device which enables very small locking steps and therefore ensures a strong, permanent contact with the inner pipe wall following its expansion, providing a strong press force on the sealing organs. The improved arresting device comprises, for this purpose, a slot arranged peripherally around the belt end on the inside, wherein a toothed bar is arranged on each of the two opposing longitudinal edges thereof. Two tensioning pinions are arranged in the slot, each of these engaging with one of the two toothed bars, and also being loaded by one locking pinion which functions as the locking organ. The locking pinion is pressed into the intermediate space between the two tensioning pinions by a tensioning spring. 
         [0010]    An internal sealing collar having such an arresting device is in need of improvement with respect to the force load which can be achieved. 
         [0011]    The aim of the present invention is therefore that of advancing the known internal sealing collars in such a manner that the arresting device can receive greater forces—that is, such that it is more difficult to unlock than previously. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    In a preferred embodiment, an internal sealing collar ( 1 ) for the purpose of insertion into pipes to seal leak points in the same, having a belt ( 2 ) which is compressed circularly and can be expanded, preferably made of sheet steel, the belt parts ( 3 ,  4 ) of which preferably overlap in the peripheral direction at least partially, and having an arresting device ( 10 ) which comprises at least two rows of teeth ( 21 ,  22 ) which are arranged parallel to each other, wherein one tensioning pinion ( 31 ,  32 ) for each of at least two of the rows of teeth ( 21 ,  22 ) engages in the same, characterized in that one locking pinion ( 41 ,  42 ) each is functionally assigned to the at least two tensioning pinions ( 31 ,  32 ), each locking pinion ( 41 ,  42 ) pressing against the associated tensioning pinion ( 31 ,  32 ) via one spring element ( 51 ,  52 ) each, and engaging with the same, and wherein each of the locking pinions ( 41 ,  42 ) additionally engages with the associated row of teeth ( 21 ,  22 ). 
         [0013]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that, for each of the at least two rows of teeth ( 21 ,  22 ), one of the tensioning pinions ( 31 ,  32 ) engages in the same. 
         [0014]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that two rows of teeth ( 21 ,  22 ) are arranged on opposite longitudinal edges ( 24 ,  25 ) of a toothed bar ( 20 ) constructed on the inside belt part ( 2 ). 
         [0015]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that each of the locking pinions ( 41 ,  42 ) has a lower tooth count than the associated tensioning pinion ( 31 ,  32 ). 
         [0016]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that each of the spring elements ( 51 ,  52 ) is a tensioning spring which is fixed by one end thereof, directly or indirectly, to the outside belt part ( 4 ), and on the other end thereof is inserted in an axle region of the associated locking pinion ( 41 ,  42 ). 
         [0017]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that the two tensioning pinions ( 31 ,  32 ) are each fixed on the outside belt part ( 4 ) via their own axle pin ( 34 ,  35 ), and the associated spring elements ( 51 ,  52 ) at least partially wind around each of these axle pins ( 34 ,  35 ). 
         [0018]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that each of two opposing rows of teeth ( 21 ,  22 ) of the toothed bar ( 20 ) belongs to an elongated first recess ( 81 ) and an elongated second recess ( 82 ), respectively, the same running parallel to each other. 
         [0019]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that the two recesses ( 81 ,  82 ) are each designed as slots. 
         [0020]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that at least one of the recesses ( 82 ) extends from one row of teeth ( 22 ) of the toothed bar ( 20 ) to an end-face end ( 2 A) of the belt ( 2 ). 
         [0021]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that each of the locking elements and/or locking pinions ( 41 ,  42 ) has an overhung mounting. 
         [0022]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that a hold-down plate ( 70 ) is included which is attached on the outside belt part ( 4 ) and overlaps at least one of the two rows of teeth ( 21 ,  22 ) with the associated tensioning pinion ( 31 ,  32 ) and locking element ( 41 ,  42 ). 
         [0023]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that the hold-down plate ( 70 ) comprises a hold-down element ( 74 )—particularly a hold-down bolt—on the side thereof which is functionally assigned to the toothed bar ( 20 ), for the purpose of pressing the toothed bar ( 20 ) toward the outside belt part ( 4 ). 
         [0024]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that the axle pins ( 34 ,  35 ) of the two tensioning pinions ( 31 ,  32 ) are designed as bolts or rivets, each projecting through corresponding bore holes ( 76 ,  77 ) of the hold-down plate ( 70 ). 
         [0025]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that the hold-down plate ( 70 ) overlaps at least a part of the two rows of teeth ( 21 ,  22 ), as well as the associated tensioning pinion ( 31 ,  32 ) and locking elements ( 41 ,  42 ). 
         [0026]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that two hold-down plates ( 70 ,  70 A;  70 B,  70 C) are included. 
         [0027]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that each of the two hold-down plates ( 70 ) additionally overlaps a slot which runs parallel to the respective row of teeth ( 21 ,  22 ), wherein a fixed bolt sits in said slot. 
         [0028]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that for each of two rows of teeth ( 21 ,  22 ), one slot, positioned opposite, is functionally assigned to the same—a bolt ( 92 ) projecting into said slot ( 90 ). 
         [0029]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that an element ( 93 ) which is able to rotate, particularly a rotating disk, is mounted on the bolt ( 92 ) or bolts. 
         [0030]    In another preferred embodiment, an internal sealing collar as described herein, characterized in that a toothed gear ( 94 ) is mounted on the bolt ( 92 ) and meshes with a further row of teeth ( 23 ) arranged in the slot ( 90 ). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  is a line drawing evidencing a perspective view, from outside into a part of an internal sealing collar, of the arresting device arranged at this point, according to a first embodiment of an internal sealing collar. 
           [0032]      FIG. 2  shows a view similar to that of  FIG. 1 , according to a second embodiment of the internal sealing collar. 
           [0033]      FIG. 3  is a line drawing evidencing an arresting device in  FIG. 1 , in a section along the dotted cutaway line in  FIG. 1 . 
           [0034]      FIG. 4  is a line drawing evidencing a cutaway view along the cutaway line I-I in  FIG. 3 . 
           [0035]      FIG. 5  is a line drawing evidencing a cutaway view of a third embodiment of an internal sealing collar according to the invention, having a relatively wider toothed bar, and two hold-down devices attached to the same. 
           [0036]      FIG. 6  is a line drawing evidencing a cutaway view of an internal sealing collar which is similar to the illustrations in  FIGS. 3 and 4 , but according to a fourth embodiment. 
           [0037]      FIG. 7  is a line drawing evidencing a cutaway view of an internal sealing collar which is similar to the illustration in  FIGS. 3 and 4 , but according to a fifth embodiment. 
           [0038]      FIG. 8  is a line drawing evidencing a cutaway view of an internal sealing collar according to a sixth embodiment. 
           [0039]      FIG. 9  is a line drawing evidencing a cutaway view of an internal sealing collar according to a seventh embodiment. 
           [0040]      FIG. 10  is a line drawing evidencing a cutaway view of an internal sealing collar according to an eighth embodiment. 
           [0041]      FIG. 11  is a line drawing evidencing a cutaway view of an internal sealing collar according to a ninth embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    The invention substantially consists of the provision of two rows of teeth, wherein a different tensioning pinion with an associated locking element engages with each. In this case, each of the locking elements is arranged with the two associated tensioning pinions is designed as a locking pinion. As a result of two rows of teeth being used, and the tensioning pinions assigned to the same, the arresting mechanism is able to receive twice the force via the toothed bar. Each of the two tensioning pinions, and also each of the locking pinions which meshes with the tensioning pinions, engage with the associated row of teeth and mesh with the same. 
         [0043]    In addition, it is advantageous that the locking forces of the tensioning pinion act on the toothed bar, thereby ensuring high static stability of the entire arrangement. Due to the use of a locking pinion which interacts with a tensioning pinion, the configuration achieves half the tooth pitch in comparison with the use of another locking element—such as a detent pin, for example. In this configuration, it is advantageous that the path traveled if the expanded internal sealing collar slips back can only be half of a tooth width. 
       DETAILED DESCRIPTION OF THE FIGURES 
       [0044]      FIG. 1  shows a perspective view of a part of an internal sealing collar  1 . The observer has a perspective of a compressed belt  2  which is preferably made of sheet steel or the like. In the rolled-up configuration shown, the belt  2  has a belt end and/or belt part  3  on the inside, and a belt end and/or belt part  4  on the outside. So that the belt  2  remains in this rolled-up configuration and its diameter cannot get smaller, a special arresting device  10  is included—and is described in detail further below. The arresting device  10  illustrated in  FIG. 1  can be seen in an enlarged illustration and from a top view in the region of  FIG. 3  marked by dashed lines. 
         [0045]    An essential feature of the arresting device  10  is a toothed bar  20  with a first row of teeth  21  and a second row of teeth  22  opposite the first. The toothed bar  20  is—as can be seen most clearly in  FIG. 1 —molded as a single piece, by its two ends, to the belt part  3  on the inside, as a result of a slot-like first recess  81  being arranged left of the first row of teeth  21 , and a similar recess  82  being arranged right of the second row of teeth  22 . However, the second recess in the embodiment in  FIG. 1  has a design which is open toward the open side of the wound-up belt  2 . In contrast, in  FIG. 2 , the recess  82  in fact has a similar design to the recess  81 . This means that in the embodiment in  FIG. 2 , the recess  82  is also bounded by a wall section  2 A of the belt  2  on the open end face. 
         [0046]    In both embodiments in  FIG. 1  and  FIG. 2 , the toothed bar  20  is—seen in the peripheral direction of the wound-up belt  2 —an integral component of the belt part  3  on the inside. In this case, the first row of teeth  21  runs along a first longitudinal edge  24 , and the second row of teeth  22  runs along a second longitudinal edge  25  of the toothed bar  20 . The two longitudinal edges  24 ,  25 , and therefore the two rows of teeth  21 ,  22 , are oriented parallel to each other. 
         [0047]    The toothed bar  20  can, with its two rows of teeth  21 ,  22 , have a length which is approximately between an eighth-circle arc and a semi-circle, or somewhat more. However, different lengths can be used. This depends to a critical degree on which outer diameter the internal sealing collar  1  needs to have to be able to seal a corresponding defective pipe. 
         [0048]    As can be seen in  FIG. 1 , the slot-like recess  81  illustrated at left is bounded on its right side by the first longitudinal edge  24 , mentioned above, which carries the first row of teeth  21  of the toothed bar  20 . On the opposing side, the recess  81  is bounded by a longitudinal edge  81   a  which does not carry any row of teeth. This longitudinal edge  81   a  is connected to the first longitudinal edge  24  on its upper and lower ends via transverse edges  81   b  and  81   c  running at a right angle. 
         [0049]    The right recess  82  comprises the second longitudinal edge  25  of the toothed bar  20 , which carries the second row of teeth  22 . In contrast to the recess  81 , the recess  82  in  FIG. 1  is open on its right, wherein the second longitudinal edge  25 , with the second row of teeth  22 , transitions on its upper end and lower end at a right angle into two transverse edges  82   b ,  82   c.    
         [0050]    As mentioned above, when the embodiment in  FIG. 2  is considered, the right recess  82  has a similar design to the left recess  81 . This means that the second longitudinal edge  25  of the toothed bar  20 , with the second row of teeth  22  arranged on the same, is situated opposite a straight longitudinal edge  82   a  which has no row of teeth. As a result, as shown in  FIG. 2 , a narrower belt section and/or strut is present which runs parallel to the longitudinal edge  82   a  of the belt  2 . This region is marked by the reference number  2 A. 
         [0051]    In each of the two recesses  81  and  82 , two rows of teeth are placed in a particular manner. Specifically, a first tensioning pinion  31  which meshes with the first row of teeth  21  is arranged in the first recess  81 . For this purpose, the first tensioning pinion  31  is mounted on an axle pin  34  which is fixed to the belt part  4  on the outside. This fixture can be achieved by riveting or welding, for example. Other connection means are likewise possible. 
         [0052]    In the embodiment in  FIGS. 1 to 3 , the first tensioning pinion has, by way of example, nine teeth which are able to mesh with the first row of teeth  21  when the first tensioning pinion  31  rotates. A first locking pinion  41  is functionally assigned to this first tensioning pinion  31 . This first locking pinion  41  has an overhung mounting. This means that the axis of the locking pinion  41  is not fixed. Rather, this first locking pinion  41  is pressed by a spring element  51  against the first tensioning pinion  31 , such that the first locking pinion  41  is held in engagement with both the tensioning pinion  31  and the first row of teeth  21 . The spring element  51  in the present case is a tensioning spring which winds around the axle pin  34  in a U shape and engages by one end thereof in a central bore hole of the locking pinion  41 . The other end is attached directly or indirectly on the outside belt part  4 . 
         [0053]    In the present embodiment, this other end of the spring element  51 —that is, the tensioning spring—is fixed by a bore hole  71  being made in a hold-down plate  70 , wherein the end of the spring element  51  which is bent at an angle can engage in the same. This hold-down plate  70  has a rectangular design, for example, and overlaps the first row of teeth  21 , as well as the first tensioning pinion  31 , the first locking pinion  41 , and the spring element  51 . The hold-down plate  70  has a fixed connection to the outside belt part  4 . This connection in the embodiment shown is the result of the fact that the axle pin  34  attached to the outside belt end  4  is also fixed to the hold-down plate  70 . As such, the axle pin  34  can be permanently riveted not only to the outside belt end  4 , but also to the hold-down plate  70 . As an alternative, it is also possible for the hold-down plate  70  to be bolted to the outside belt end. 
         [0054]    As can be seen in  FIGS. 1 to 3 , a second tensioning pinion  32  with a second locking pinion  42  and a second spring element  52 , in the form of a tensioning spring, is arranged on the second row of teeth  22  in a similar manner. The ends of this second spring element  52  are again inserted into a bore hole of the second spring element  52 , and into a corresponding bore hole  72  of the hold-down plate  70 . The locking element  42  in this case winds around the axle pin  35  around an angle of approximately 180°, wherein the second tensioning pinion  32  can rotate around said axle pin [ 35 ]. This axle pin  35  as well can be designed as a rivet or bolt. 
         [0055]    The hold-down plate  70  serves the purpose of pressing the toothed bar  20  down during the tensioning process. For this purpose, a hold-down element  74 —for example in the form of a plastic knob—can be attached on the side of the hold-down plate  70  which faces the toothed bar  20 . The toothed bar  20  glides along this hold-down element  74  when the internal sealing collar  1  is expanded, and is pressed down. This can be very clearly seen in  FIG. 4 , which shows a cutaway view of  FIG. 3  along the cutaway line I-I shown in the same figure. It can be seen that the hold-down element  74  sits on the toothed bar  20 . 
         [0056]    In the embodiments presented in  FIGS. 1 to 3 , each of the tensioning pinions  31 ,  32  has a lower tooth count than the two locking pinions  41 ,  42 . This can, but need not necessarily, be the case. 
         [0057]    The functionality of such an arresting device  10  is as follows. 
         [0058]    When the internal sealing collar  1  is installed in a pipe being sealed, the internal sealing collar  1  is initially introduced with a reduced diameter, and therefore in a somewhat rolled-up state, into the pipe being sealed. An assembly dolly is used for this purpose, bringing the internal sealing collar  1  to the necessary point in the pipe being sealed. Once arrived at the point to be sealed, the assembly dolly effects the expansion of the internal sealing collar. To this end, the inside belt part  3  is moved along the direction of arrow P 1  relative to the outside belt part  4 . A direction of movement corresponding to the arrow P 1  is possible because the two locking pinions  41 ,  42  with an overhung mounting yield, along the direction of arrow P 2  shown in  FIG. 3 , outward and therefore away from each other, thereby allowing the two tensioning pinions  31 ,  32  to rotate freely about their axle pins  34 ,  35  due to the two rows of teeth  21 ,  22  being pushed upward. 
         [0059]    In contrast, a movement against the direction of arrow P 1  is essentially impossible because the arresting device  10 , described above, locks in this case. The two tensioning springs  51 ,  52  pull the two locking pinions  41 ,  42  in the direction of the tensioning pinions  31 ,  32 , and therefore likewise engage with the same, as well as the two rows of teeth  21 ,  22  of the toothed bar  20 . A movement of the inner belt part  3  against the direction of arrow P 1  is therefore effectively blocked. 
         [0060]    As a result of the fact that each of the two separate tensioning pinions  31 ,  32  on the toothed bar  20  engages with its own locking pinion  41 ,  42 , a greater arresting force is reached compared to conventional arresting devices. The high arresting forces are the result of the fact that the arresting device has four toothed gears—that is, the two tensioning pinions  31 ,  32  and the associated locking pinions  41 ,  42 —all of which engage with the toothed bar  20  in the locking direction. 
         [0061]    Due to the fact that the locking forces of the tensioning pinion  31  and the associated locking pinion  41 , left and right on the toothed bar  20 , act on the tensioning pinion  32  and the associated locking pinion  42  on the right row of teeth  22 , the locking forces of these toothed gears advantageously work against each other, thereby resulting in an increased static stability of the entire arrangement. In contrast to EP 0 805 932 B1, cited in the introduction to the descriptive portion, the locking forces of the two tensioning pinions in the internal sealing collar described therein act away from each other. 
         [0062]      FIG. 5  shows a third embodiment of an internal sealing collar, in the region of the arresting device  10 . In contrast to the embodiments above, the toothed bar  20  in this case is significantly wider, and the hold-down plate has a two-part design. This means that there is not only one hold-down plate which overlaps the entire toothed bar  20  and the associated tensioning pinions  31 ,  32  and locking pinions  41 ,  42 . Rather, one smaller hold-down plate  70 A is included for each, only overlapping a portion of the toothed bar  20 , and being fixed—by way of example riveted or bolted—to the outside belt part  40  via a bolt  78 . This bolt  78  is positioned, as shown in  FIG. 4 , in the recess  81  for the hold-down plate  70 A illustrated at left therein. The hold-down plate  70 B overlaps a left-hand part of the toothed bar  20 , and is fixed—that is, riveted or bolted—to the outside belt part  4  via a bolt  78 . This bolt  78  is positioned, as shown in  FIG. 4 , in the recess  81  for the hold-down plate  70 A illustrated at left therein. In addition, each of the regions of the hold-down plates  70 A,  70 B which overlap the intermediate bar  20  is configured with a downward embossment  70 C which extends downward toward the toothed bar  20  and thereby functions as a hold-down device for the toothed bar  20 . 
         [0063]    A similar hold-down plate  70 B overlaps a part of the second row of teeth  22  in a similar manner, as well as the second tensioning pinion  32  found there and the associated second locking pinion  42 . This second hold-down plate  70 B is again fixed—that is, riveted or bolted—to the outside belt part  4  via a bolt  79 . The two hold-down plates  70 A and  70 B illustrated in  FIG. 4  are again attached by means of axle pins  34 ,  35  to the outside belt end  4  of the internal sealing collar. 
         [0064]    The third embodiment illustrated in  FIG. 6  is similar to the embodiment in  FIGS. 1 to 3 . However, in the regions A and B, two identical arresting devices  10  arranged parallel to each other are configured in the embodiment. The reference numbers used above are used again in  FIG. 6 , but doubled. 
         [0065]    A further embodiment of an internal sealing collar is shown in detail in  FIG. 7 . The illustration corresponds to the embodiment in  FIG. 6 , with one difference. The difference is that a slot and/or gap  100  is included between the two toothed bars  20 , extending from the one end of the two toothed bars  20  to the other end of the toothed bars, and projecting further to the end of the outside belt part  3 . This gap and/or slot  100  makes it possible to compensate for a twisting of the internal sealing collar when the same is tensioned. The gap and/or slot  100  in this case has a design with a width such that the corresponding parts of the inside belt end  3  do not overlap when the internal sealing collar is twisted. 
         [0066]    Finally, it is noted that the toothed gears illustrated—that is, the two tensioning pinions  31 ,  32  and the associated locking pinions  41 ,  42 —can have different tooth counts. In addition, these toothed gears can also have designs with different heights and/or different thicknesses. However, a configuration wherein these toothed gears are identical in both tooth count and thickness is also within the scope of the invention. 
         [0067]    At least the toothed gears consist advantageously of steel—preferably V4A steel—or titanium. Titanium has the advantage of being resistant to acid. The hold-down plates  70  can also be manufactured from these materials. 
         [0068]    Finally, it is noted that the internal sealing collar can be entirely surrounded, on its outer side, by a tube made of rubber-elastic material. In addition, it is also possible that the internal sealing collar  1  is connected, on the outer side, with rubber elastic sealing strips. This increases the sealing effect of the internal sealing collar  1  when the same is placed on the pipe being sealed. 
         [0069]    A sixth embodiment of an internal sealing collar according to the present invention is shown by way of example in  FIG. 8 , in the region of the arresting mechanism. The reference numbers used above continue to indicate the same parts. The arresting mechanism in this case includes two toothed bars which are arranged in mirror image to each other along a center line X, positioned respectively to the left and right of a slot  90 ,  91 —in the top view in  FIG. 8  of the left part of the arresting mechanism—the slot  91  is positioned closer to the left edge of the belt  20 , while the slot  90  is arranged closer to the center line X, and runs parallel to this center line X. The slot  91  has a straight contour toward the left belt end, and comprises a row of teeth  21  on its side which faces the center line X. The tensioning pinion  31  and the locking pinion  41  engage with this row of teeth  21  in the manner described above. The locking pinion  41  also meshes with the tensioning pinion  31 . The spring element is again indicated with the reference number  51 . The right slot  90  has a straight contour toward the center line X, and comprises a row of teeth  23  which faces the row of teeth  21 . A bolt  92  is positioned in the slot  90 , wherein a toothed gear and/or pinion  94  is mounted on the same in a manner allowing rotation. This toothed gear  94  meshes with the row of teeth  23 . A hold-down element  70 A overlaps the slot  90 ,  91  in the manner illustrated in  FIG. 8  in the region of the tensioning pinion  31 , locking pinion  41 , and toothed gear  94  configured at that position. The hold-down element  70 A again establishes a fixed connection between a bolt  78  and the belt  2 . 
         [0070]    In a similar manner, a further arresting mechanism is positioned in a mirror image on the right side of the center line X. The two slots  90 ,  91  comprise rows of teeth  22 ,  24  which face each other. A bolt  92  engages in the left slot in  FIG. 8 , wherein a toothed gear is mounted on the same in a manner allowing rotation, and engages with the row of teeth  24 . A tensioning pinion  32  and a locking pinion  42  are mounted in the manner described above in the slot  91  illustrated at far-right, wherein the locking pinion  42  is pressed against the tensioning pinion  32  via the spring element  52 . A hold-down element  70 B overlaps the slot  90 ,  91  in a similar manner to the hold-down element  70 A, in the region of the toothed gears and/or pinions mentioned above. The hold-down element  70 B is fixed to the belt  2  via a bolt  79 . 
         [0071]    The embodiment illustrated in  FIG. 9  is very similar to the embodiment in  FIG. 8 . However, the toothed gears and pinions are arranged in the slots  90 ,  91  in opposite configurations to each other. This means that in  FIG. 9 , in the slot  90  illustrated at left—that is, the slot which is closest to the left belt end—a bolt  92  projects into the slot  90 , wherein a toothed gear  94  is mounted on the same in a manner allowing rotation. This toothed gear  94  meshes with the row of teeth  23 . A slot  91  is positioned to the right thereof, with a row of teeth  21  which the tensioning pinion  31  and the locking pinion  41  engage with. A similar arrangement of tensioning pinion  32 , locking pinion  42 , spring element  52 , and bolt  92  is found on the right side of the center line X in  FIG. 9 , placed in mirror image. 
         [0072]    The embodiments in  FIG. 10  and  FIG. 11  are similar to the embodiments in  FIG. 8  and  FIG. 9 . The only difference is that in this case there is no row of teeth constructed in the slots  90 . Rather, only one bolt  92  projects into these slots, wherein a disk  93  which is capable of rotation is preferably mounted on the same. This rotating disk  93  is supported in the slot  90  on one edge. 
       LIST OF REFERENCE NUMBERS 
       [0000]    
       
           1  internal sealing collar 
           2  belt 
           2 A end-face belt 
           3  inside belt part, belt end 
           4  outside belt part, belt end 
           10  arresting device 
           20  toothed bar 
           21  first row of teeth 
           22  second row of teeth 
           24  first longitudinal edge 
           25  second longitudinal edge 
           31  first tensioning pinion 
           32  second tensioning pinion 
           41  first locking element 
           42  second locking element 
           43  bore hole 
           44  bore hole 
           34  axle pin 
           35  axle pin 
           51  first spring element 
           52  second spring element 
           70  hold-down plate 
           70 A hold-down plate 
           70 B hold-down plate 
           70 C downward embossment 
           71  bore hole 
           72  bore hole 
           74  hold-down element 
           78  bolt 
           79  bolt 
           81  first recess 
           81   a  straight longitudinal edge 
           82  second recess 
           82   b  transverse edge 
           82   c  transverse edge 
           90  slot 
           91  slot 
           92  bolt+ 
           93  disk, rotating element 
           94  toothed gear 
           100  gap on inside belt end  3   
         A first region 
         B second region 
         P 1  arrow 
         P 2  arrow 
           2 A edge 
         I-I cutaway line 
         X center line 
       
     
         [0121]    The references recited herein are incorporated herein in their entirety, particularly as they relate to teaching the level of ordinary skill in this art and for any disclosure necessary for the commoner understanding of the subject matter of the claimed invention. It will be clear to a person of ordinary skill in the art that the above embodiments may be altered or that insubstantial changes may be made without departing from the scope of the invention. Accordingly, the scope of the invention is determined by the scope of the following claims and their equitable equivalents.