Abstract:
A wound tube is made of profiled plastic strips, the profiling of which comprises at least the edge region. The edge region is designed such that edge regions of successive coils, the edge regions lying mutually adjacent during winding, can be connected in a form-fitting manner, and at least one of the surfaces of the plastic strips has ribs projecting perpendicularly essentially to one side in order to form a flat inner surface during winding. The tube wall of the wound tube is designed as a double wall and is assembled from a first inner plastic strip and from a second outer plastic strip, wherein the ribs projecting perpendicularly essentially to one side fix the distance of the outer plastic strip from the inner plastic strip. A device with which such wound tubes can be advantageously produced on-site is also provided.

Description:
BACKGROUND AND SUMMARY 
       [0001]    The present application is a divisional of U.S. application Ser. No. 13/392,809, filed Feb. 27, 2012, which is the U.S. national stage of international Application No. PCT/EP2010/062650, filed Aug. 30, 2010, which claims priority to DE102009043932.3, filed Sep. 2, 2009, all of which are incorporated by reference. 
         [0002]    The invention concerns a wound tube made of profiled plastic strips whose edge regions are designed such that when winding contiguous edge regions of the plastic strip of two successive windings [said windings] can be connected in a form-fitting manner and in which at least one of the surfaces of the plastic strip has ribs that essentially project, orthogonally and are equally spaced. 
         [0003]    Wound tubes made of plastic strips are used in the restoration of waste water channels and are produced on site. In a process disclosed in EP 2 085 29 A1, DE 696 27 426 T2 or DE 696 35 214 T2 the tube is made in the waste water channel whereby the assembler moves through the waste water channel as the production progresses and makes the wound tube from a profiled plastic strip that is guided through its assembler portion. In a different process that is disclosed in EP 0 023 242 or EP 0 109 413 the assembler is stationary in a revision shaft of the waste water channel that is to be restored and the profiled plastic strip is provided via the revision shaft. The wound tube that is made by the assembler is inserted into the channel as it is finished. The plastic strips used for making such wound tubes comprise a groove extending longitudinally along an edge side and a bead extending longitudinally along the other edge side so that the bead of the one edge region fits into the groove of the subsequent edge region in a form-fitting manner during winding. This form-fitting results in a tight connection which can be improved using additional means, for example cold welding. 
         [0004]    In such wound tubes poor stability, at least in large diameter tubes, is a disadvantage. By including radially projecting ribs on the outer surface of the plastic strip forming the outer wall, stability can be increased, however, here, too, the diameter for stable wound tubes is limited. To compensate for this insufficiency and to provide sufficient stability, the hollow spaces that necessarily remain between the wall of the waste water channel and the wall of the wound tube in these manufacturing processes must be filled. 
         [0005]    It is desirable to provide a wound tube with increased stability that can easily and inexpensively be produced with profiled plastic strips on site for the restoration of waste water channels and can be introduced into the channel to be restored without any complete filling; furthermore a device is to be provided with which such wound tubes can advantageously be produced on site. 
         [0006]    In wound tubes according to an aspect of the invention, the tube walls are double walls. To this end a first, inner plastic strip and a second outer plastic strip are joined so that the two plastic strips are at a radial distance from one another. Essentially orthogonally projecting ribs of the two joined plastic strips are arranged radially and opposite one another for support purposes. The arrangement is such that the edge region of the one plastic strip is offset by at least one rib distance in axial direction in relation to the edge region of the other plastic strip. By offsetting the edge region of the inner plastic strip in relation to the edge region of the outer plastic strip, joining them automatically is facilitated. The plastic strip filtrating the outer wall advantageously also has ribs projecting on the outside, which significantly increases the stability of the resulting wound tube. Such plastic strips can easily be produced using extrusion. 
         [0007]    In an advantageous further development at least some of the ribs, preferably all of them, of one of the plastic strips are reinforcement ribs with a rib head. The ribs of the other plastic strip corresponding to these ribs comprise a head receptacle that can accommodate the respective rib heads. After the two plastic strips are joined to form the double wall band, the respective rib heads are inside the respective head receptacles—in this manner the inner and outer plastic strips are joined in a form-fitting manner. 
         [0008]    It further is advantageous for both plastic strips to comprise reinforcement ribs with rib heads and ribs with head receptacle. They are arranged alternately so that both identically designed plastic strips can be joined to form the plastic band by joining the ribs that face each other. After the two plastic strips are joined, the respective rib heads are located in the respective head receptacles in a form-fitting manner. This means production is restricted to one plastic band with a uniform cross-section and only spools of identical plastic strips with a uniform cross-section are required on site. 
         [0009]    This connection is locked into position. To this end the engaging rib heads are designed as a kind of harpoon head and the head receptacles are designed accordingly so that when the outer plastic strip and the inner plastic strip are joined, they slide into place and automatically secure the connection. To make this permanent, it is possible to glue or weld the connection. To this end at least some of the rib heads and/or head receptacles contain glue or an agent that results in cold welding and thus can be glued or welded together. 
         [0010]    When producing the wound tube, the two plastic strips are joined to form a double strip and are bent around a bend radius that corresponds to the diameter of the tube to be inserted into the channel that is to be restored. This results in a difference in length between the outer plastic strip and the inner plastic strip. To compensate for this difference in length, at least one of the plastic strips comprises means for compensating for the length. To this end it is advantageous to have U-shaped or OMEGA-shaped elbows between two reinforcement ribs or between two ribs. 
         [0011]    To secure the connection of the edges, a counter bracket with latch head receptacle is provided in one edge region of the plastic strips while the other edge region of the second plastic strip comprises a retaining rib with a retaining rib head. This retaining rib head is designed such that it is inserted into the latch head receptacle of the counter bracket and latches when the edge regions of the two plastic strips of two adjacent windings of the wound tube are joined. It further is advantageous when a locking rib is molded at an obtuse angle to the edge region of one of the plastic strips. When the edge regions of the two plastic strips are joined, said locking rib rests against and blocks the outermost reinforcement rib. It is understood that in order to maintain the uniform cross-section, one of the edge regions of the plastic band must comprise counter brackets with latch head receptacles and the other edge region must comprise retaining ribs with retaining rib heads and one edge region comprises a locking rib arranged at an obtuse angle. 
         [0012]    A suitable device for producing such wound tubes is a set of rollers that is arranged in the area of the mouth of the channel that is to be restored said set of rollers forming the winding for the wound tube. However, it comprises a roller advance for joining the two plastic strips to form the double band required for the wound tube so that the joined double band is fed to the set of rollers for forming the winding. 
         [0013]    It is advantageous when the roller set is preceded by a device with which glue or an agent for cold welding the engaging ribs of the plastic strips and/or the engaging edge regions of the plastic strip can be applied. These means secure the per se solid latching of the joined plastic strips. 
         [0014]    When applying the glue or the agent for cold welding in the glue application device, the application occurs with a roller. To this end an application roller runs through a glue reservoir and takes up glue when it resurfaces. Then the glue or the agent for cold welding that was taken up is transferred to the respective areas of the plastic strip hereby pressure rollers ensure that the application is carried out properly. A different process would be a spray on process whereby areas of the plastic strip that do not need to be sprayed are covered in the spray area. In both cases it is possible to arrange wipe off devices that remove any excess glue. For certain types of glue joining must occur immediately after the glue is applied. In this case the glue application device is arranged directly in front of the rollers that join the two plastic strips. If the glue must dry for a certain period of time, the time period can be adjusted by selecting the corresponding distance between the glue application device and the rollers that join the two plastic strips and taking the respective feed rate into account. An application with other means, such as spray cans, is possible as well. 
         [0015]    The plastic strips are removed from the storage spools that are above ground and are fed to the on-site winding assembler through the revision shaft. In doing so, the surface of the plastic strips can pick up dirt, which can impede the latching of the ribs and the edge regions. To avoid this problem and to protect the plastic strips that are removed from the storage spools and fed to the winding assembler with intake roller set through the revision shaft, means for protecting the profile are arranged in the revision shaft that surround both plastic strips and thus protect them against dirt in particular. In case of deep channels the suspended load of the plastic strips that are fed to the winding assembler through the revision shaft can become so high that it might affect the teed process. In such cases it is advantageous to include additional brake rollers that take up at least part of the load. Said brake rollers advantageously are arranged in the protection guide. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The character of the invention is described in more detail based on the exemplary embodiments shown in  FIGS. 1 through 8 . The following is shown: 
           [0017]      FIG. 1 : Wound tube being assembled (schematically); 
           [0018]      FIG. 2 : Inner strip (profile); 
           [0019]      FIG. 3 : Outer strip (profile); 
           [0020]      FIG. 4 : Joined inner and outer strip; 
           [0021]      FIG. 5 : Double strip prior to joining the edge regions; 
           [0022]      FIG. 6 : Double strip with joined edge regions; 
           [0023]      FIG. 7 : Double strip rib heads and bead receptacles glued; 
           [0024]      FIG. 8 : Channel restoration with wound tube (schematically); 
           [0025]      FIG. 9 : Winding assembler in bottom of shaft with glue application device. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    To produce the wound tube  1 , first the inner plastic strip  10  is joined with the outer plastic strip  20  to form the double band  30  ( FIG. 8 ) from which the wound tube  1  is formed in a winding assembler  4  that is positioned in a stationary manner in front of the mouth of the channel that is to be restored “KA” and then, with each new winding of the wound tube  1 , is advanced inside the channel by one strip width of the double band  30 . This is supported on one hand by the intake rollers  7  and  8  that are arranged in the roll-former type shaped intake  6  and that precede the winding assembler  4 .  FIG. 1  shows a schematic view of the winding assembler  4 . 
         [0027]    Using the winding cage  5  and the rollers  5 . 1  of the winding assembler  4  the double band  30  is positioned in the curvature that is adjusted to the curvature radius of the preceding winding of the wound tube  1  and the edge regions  14 . 1  and, respectively,  24 . 1  of the inner and outer plastic strip  10  and, respectively,  20  are aligned with the corresponding edge regions  14 . 2  and, respectively,  24 . 2  of the inner plastic strip  10 ′ and, respectively, the outer plastic strip  20 ′ of the double band  30 ′ of the preceding winding while these edge regions are joined to form the complete wound tube. 
         [0028]    To be able to connect the two plastic strips  10  and  20  and to join their edge regions when making the wound tube  1 , the two plastic strips  10  and  20  have correspondingly complementary profiles that are described below: 
         [0029]      FIGS. 2 and 3  show a cross-section of the two plastic strips  10  and  20  and their profiles. Between its edge regions  14 . 1  and  14 . 2  the inner plastic strip  10 , on the wall that serves as the inside, comprises ribs that project essentially orthogonally that are support ribs  12 . The free ends of the support ribs  12  are formed as rib heads  13 . Between its two edge regions  24 . 1  and  24 . 2  the outer plastic strip  20  also comprises ribs  22  whose free ends are formed as head receptacles  23 . 
         [0030]    These head receptacles  23  are designed such that the rib heads  13  of the opposite support ribs  12  can be inserted and connected in a form-fitting manner. It is advantageous to apply glue to at least some of the head receptacles  23  or at least some of the rib heads  13  ( FIG. 7 ) that provides cold welding. Between two ribs  22  of the outer plastic strip  20  there are elbows  29 —here shown to be U-shaped—to compensate for expansion. 
         [0031]    To form the wound tube  1 , the edge regions  14 . 1 ,  14 . 2  and  24 . 1  and  24 . 2  of two windings of the coil that are contiguous during winding must be joined. It is understood that latch head  15  and edge receptacle  18  or counter bracket  25  and latch head receptacle  26  and engaging rib head  27  of the edge rib  16  or counter bracket head  27 . 1  of the counter bracket  27  are at a distance from another by one circumferential length of the coil of the wound be  1  in rolling direction of the plastic snip  10 . To this end the edge region  14 . 1  of the first, inner plastic strip  10  comprises a molded latch had  15  and the edge region  14 . 2  of the other side of this plastic strip  10  comprises an edge rib  16  with a rib head  17 . The latch head  15  comprises an edge receptacle  18  into which the rib head  17  can be inserted in a form-fitting manner when joined. 
         [0032]    The edge regions  24 . 1  and  24 . 2  of the outer plastic strip  20  are joined analogously. Here, the one edge region  24 . 1  of the outer, second plastic strip  20  comprises a latch head receptacle  26  while the other end  24 . 2  comprises a counter bracket  27  with a counter bracket head  27 . 1 . This counter bracket head  27 . 1  is inserted into the latch head receptacle  26  in a form-fitting manner when joined. This joining process is shown in individual steps in  FIGS. 2 ,  3 , and  4  for explanation purposes.  FIG. 5  shows the position of the plastic strips  10  and  20  of two successive windings before they are joined to the wound tube  1  comprised of the two plastic strips  10  and  20 , said joining process being complete in  FIG. 6 . In  FIGS. 5 and 6  the plastic strips of the subsequent winding are identified as  10 ′ and  20 ′. 
         [0033]    To prevent the connection of the edge regions of the plastic strips  10  and, respectively,  20  of adjacent windings from separating using mechanical means, locking mechanisms are provided. To this end a locking rib  19  is molded to the edge region  14 . 1  of the first, inner wound tube  10  [sic]. When joined, the free end of the locking rib  19  rests against the adjacent support rib  12  of the edge region of the plastic strip  10  of the subsequent winding  10 ′, thus locking this latched connection. 
         [0034]    To secure the form-fitting connection of the plastic strips  10  and  20  as well as the edge regions of the plastic strips  10 ,  10 ′ and  20 ,  20 ′ of contiguous windings of a wound tube  1  in relation to one another, they are secured by gluing or cold welding them. To this end glue or an agent for cold welding is provided that are applied to the opposing insides of at least one of these plastic strips. This is shown schematically in  FIG. 7  in an embodiment with the two plastic strips  10  and  20  between the intake rollers  7  and  8 . Here the glue/agent was applied to the rib heads  13  that are latched into the head receptacles  23 , thus securing the mechanical connection between the two by means of additional adhesive forces. 
         [0035]    By connecting two plastic strips  10  and  20  to form the double strip and by bending it to adjust it to the curvature diameter of the wound tube, there is a difference in length because the circle length of the outer plastic strip  20  is correspondingly longer by the difference of the two radiuses. To compensate for that there are (as already described above) compensation means on one hand, and on the other hand the connecting points of two outer plastic strips shift in relation to the connection points of the inner plastic strips. This shift ensures that the connecting points of two outer plastic strips and the connecting points of two inner plastic strips are not on top of each other, which benefits production. 
         [0036]    To restore a channel “KA” on site—as shown schematically in FIG.  8 —two plastic strips  10  and  20  are used, plastic strip  10  for the inner band and the second plastic strip  20  for the outer band, that are stored on customary transport spools  35  from which they can be unwound, said transport spools being on a transport vehicle “TW” that is parked on the surface level “O” near the mouth of a revision shaft “RS”. Once unwound from the transport spools  35 , the two plastic strips  10  and  20  are fed through the revision shaft “RS” and to a winding assembler  4  which is set up at the bottom in front of the channel “KA” that is to be restored. To this end there are intake guides  36  above the mouth of the revision shaft “RS”, which, in the exemplary embodiment shown, are held by the boom of a wheel loader “RL”. Alternatively, this intake guide  36  could also be held b a mouth attachment  34  placed on the mouth of the revision shaft “RS”. 
         [0037]    The winding assembler  4  is preceded by the intake rollers  7  and  8  with which the two plastic strips  10  and  20  are joined to form the double band  30 . This double band  30  is fed into the winding assembler whose intake  4 . 1 , which is designed like a roll former and can also include the intake rollers  7  and  8  as an integrated component, aligns this double band  30  so that it is routed from the winding cage  5  of the winding assembler  4  into the curvature of the channel “KA” that is to be renovated and the edge regions [of said double band] are brought into contact with the edge regions of the inner band and otter band of the preceding winding of the wound tube  1 , said edge regions being adjacent during winding (as is shown in  FIGS. 5 and 6 ), and can be joined. 
         [0038]    The plastic strips  10  and  20  that run through the revision shaft “RS” must be free of damage and other particles so the plastic strips can be joined. To ensure this, a profile protection  37  is provided in the revision shaft “RS” through which the plastic strips  10  and  20  run and thus are protected. This profile protection  37  is comprised of individual links  38  with approximately rectangular cross-section that are articulated in relation to one another and can be held by the boom of the wheel loader “RL” or a mouth attachment  34  placed on the mouth of the revision shaft “RS” or even by a separate crane. 
         [0039]    In order to ensure that the plastic strips  10  and  20  that are to be joined are sufficiently clean, brush inserts  39  are provided. These brush inserts  39  expediently are located in the intake of the plastic strips  10  and  20  into the profile protection. If glue is to be applied, brushing expediently occurs prior to the application of the glue and the brush inserts  39  precede the device for applying glue. 
         [0040]    If the channel that is to be restored  2  is very deep, it may be necessary to provide means that take up the load of the suspended plastic strip  10  and, respectively,  20  in the profile protection  37 . Suitable means are roller arrangements with U-shaped or OMEGA-shaped deflection of the plastic strips. 
         [0041]    To secure the latching of the two plastic strips  10  and  20  to form the double band  30  by means of gluing or cold welding, glue application devices  40  ( FIG. 8 ,  9 ) are provided that comprise an application roller  41  that runs through a glue reservoir and a pressure roller  43 . In the process the pressure roller  43  guides the plastic strips  10  or  20  to which glue is to be applied in such a way that its surface that faces the other plastic strip  20  or  10  when they are joined, is in contact with the application roller  41 . In the exemplary embodiment shown the inner plastic strip  10  and its ribs  12  with rib heads  13  is guided such that glue is applied to the rib heads  13  whereby the width and/or profiling of the application roller  41  determines the number of rib heads  13  to which glue is applied. This glue application device  40  can be arranged at the intake  4 . 1  in the winding assembler  4  ( FIG. 9 ). In a different arrangement shown in  FIG. 8 , the glue application device  40  is located on the mouth attachment  34  whereby the glue supply to the glue reservoir  42  is not shown in either case. The plastic strips  10  and  20  that are prepared in this manner then are joined and latched in the intake rollers  7  and  8  or in the roller set of the intake  5  of the winding assembler  4  whereby the gluing or welding occurs. It is understood that the intake rollers  4 . 1 , which are shown as two rollers here and cause the two plastic strips to join, also could be a multi-stage roller set. 
       REFERENCE NUMBERS 
       [0000]    
       
           01 : wound tube 
           02 : 
           03 : 
           04 : winding assembler 
           04 . 1  intake 
           05 : winding cage 
           05 . 1 : rollers 
           06 : intake 
           07 : intake rollers 
           08 : intake rollers 
           09 : 
           10 : inner plastic strips 
           10 ′ winding 
           11 : strip base 
           12 : support ribs 
           13 : rib heads 
           14 . 1  edge region of the inner plastic strip  10   
           14 . 2  edge region of the outer plastic strip 
           15 : latch head 
           16 : edge rib 
           17 : rib head 
           18 : edge rib/edge receptacle 
           19 : locking rib 
           20 : outer plastic strip 
           22 : ribs 
           23 : head receptacle 
           24 . 1  edge region of the inner plastic strip  10   
           24 . 2  edge region of the outer plastic strip  10 /end 
           25 . counter bracket 
           27 : counter bracket head 
           27 . 1  counter bracket head 
           28 : latch head receptacle 
           29 : elbows 
           30 : double band 
           31 : 
           33 : 
           34 : mouth attachment 
           35 : transport spools 
           36 : intake guides 
           37 : profile protection 
           38 : links 
           39 : brush inserts 
           40 : glue application devices 
           42 : glue reservoir 
           41 : application roller 
           42 : glue reservoir 
           43 : pressure roller 
         KA: channel “KA” 
         O: surface level “O” 
         RS: revision shaft “RS” 
         RL: wheel loader “RL” 
         TW: transport vehicle “TW”