Patent Publication Number: US-11660772-B2

Title: System for producing lengths of tube comprising helically wound strips

Description:
FIELD OF THE INVENTION 
     The invention relates to a system for producing lengths of tube, such as drinking straws, comprising helically wound strips. The system comprises a mandrel, a winding device for helically winding strips around the mandrel to form a base tube moving away from the mandrel at a tube speed, a strip suppling device for supplying the strips to the winding device, and a cutting device for cutting the base tube at a predetermined length to form the lengths of tube while the base tube is moving in a tube direction at the tube speed. 
     BACKGROUND OF THE INVENTION 
     The invention is based on the inside that the known system extends along a relatively large distance in the tube direction and/or operate relatively slow. 
     SUMMARY OF THE INVENTION 
     The invention has the objective to provide an improved (or at least alternative) system for producing lengths of tube, such as drinking straws, comprising helically wound strips. According to a further aspect, the invention has the objective to provide a system which is relatively shorter in the tube direction. According to a further aspect, the invention has the objective to provide a system which operates relatively faster. 
     For this reason, the system comprises a mandrel, a winding device for helically winding strips around the mandrel to form a base tube moving away from the mandrel at a tube speed, a strip suppling device for supplying the strips to the winding device, a cutting device for cutting the base tube at a predetermined length to form the lengths of tube while the base tube is moving in a tube direction at the tube speed, wherein the cutting device comprises a knife which is movable along a knife trajectory surrounding a centre axis and extending over a knife axial distance along the centre axis, the knife trajectory forms, when viewed in a direction of the centre axis, a virtual circle having a knife radius distance and a circle centre coinciding with the centre axis, the knife trajectory comprises a cutting part in which the knife is moved over the knife axial distance in the tube direction while, when viewed in the direction of the centre axis, moving along the virtual circle, the knife trajectory further comprises a retrieving part in which the knife is moved over the knife axial distance and opposite to the tube direction while, when viewed in the direction of the centre axis, moving along the virtual circle, the cutting device is configured to cut the base tube with the knife moving along the cutting part of the knife trajectory, the cutting device comprises a first displacement unit configured to displace the knife around the centre axis and, when viewed in the direction of centre axis, along the virtual circle, a second displacement unit configured to displace the knife over the knife axial distance in the tube direction and opposite thereto, and a knife displacement drive which is operatively coupled to the first displacement unit and the second displacement unit and configured to move the knife, when viewed in the direction of the centre axis, along the virtual circle at a rotational knife speed and to move the knife over at least part of the knife axial distance in the tube direction at an axial knife speed equal to the tube speed when the knife moves along the cutting part of the knife trajectory and cuts the base tube. 
     In this system, the knives of the cutting device extend over a relatively short distance in the tube direction. As a result, the system is relatively shorter in the tube direction. 
     In an embodiment according to the system, the cutting device comprises a counterweight which is movable along the knife trajectory or at a counterweight trajectory at a constant counterweight distance from the knife trajectory to balance the movement of the knife along the trajectory. 
     In an embodiment according to the system, the counterweight is a further knife which is movable along the knife trajectory and configured to cut the base tube. 
     In an embodiment according to the system, the cutting device comprises multiple knives which are movable along the knife trajectory to cut the base tube and the first displacement unit and the second displacement unit are configured to continuously displace a same number of knives along the cutting part of the knife trajectory as displaced along the retrieving part of the knife trajectory. 
     In an embodiment according to the system, the knives are, when viewed in the direction of the centre axis, located at an equal distance from each other along the virtual circle. 
     In an embodiment according to the system, the cutting device comprises an even number of knives. 
     In an embodiment according to the system, the cutting part and the retrieving part of the knife trajectory are, when viewed in the direction of the centre axis, located at opposite sides of the virtual circle. 
     In an embodiment according to the system, the cutting part of the knife trajectory has a cutting part length, the retrieving part of the knife trajectory has a retrieving part length, and the retrieving part length is equal to the cutting part length. 
     In an embodiment according to the system, the second displacement unit is configured to move the knife at an axial knife speed equal to the tube speed and opposite to the tube direction when the knife moves along the retrieving part of the knife trajectory. 
     In an embodiment according to the system, the cutting part of the knife trajectory starts at a cutting part starting position on the knife trajectory and ends at a cutting part ending position on the knife trajectory, the retrieving part of the retrieving trajectory starts at a retrieving part starting position on the knife trajectory and ends at a retrieving part ending position on the knife trajectory, the retrieving part ending position and cutting part starting position coincide, and the cutting part ending position and the retrieving part starting position coincide. 
     In an embodiment according to the system, the knife trajectory has, when viewed in a transverse direction extending perpendicular to the centre axis, an oval-like shape. 
     In an embodiment according to the system, the first displacement unit comprises a knife support holding the knife at the knife radius distance from the centre axis, while allowing movement of the knife over the knife axial distance parallel to the centre axis, the first displacement unit is configured to rotate the knife support around the centre axis, while holding the knife at the knife radius distance from the centre axis, and the second displacement unit comprises a cam coupled to the knife and a cam track configured to displace the knife over the knife axial distance parallel to the centre axis in the tube direction when the knife moves along the cutting part of the knife trajectory and to move the knife over the knife axial distance parallel to the centre axis and opposite to the tube direction when the knife move along the retrieving part of the knife trajectory. 
     In an embodiment according to the system, the knife is a rotating knife having a rotation axis extending parallel to the centre axis. 
     In an embodiment according to the system, the knife is operatively attached to a knife rotation gear wheel surrounding the rotation axis of said knife, the cutting device comprises a knife rotation gear ring engaging the knife rotation gear wheel of the knife and having a knife rotation ring centre coinciding with the centre axis, and the knife rotation gear wheel and the knife rotation gear ring cooperate to rotate the knife about its rotation axis when the knife is, when viewed in the direction of the centre axis, moved along the virtual circle. 
     In an embodiment according to the system, knife rotation gear ring is rotatable about the knife rotation ring centre and the cutting device comprises a knife rotation drive configured to rotate the knife rotation gear ring about the knife rotation ring centre in order to control a rotational cutting speed with which the knife rotates around its rotation axis. 
     In an embodiment according to the system, the cutting device is configured to move the knife through only part of the base tube when the knife is moved along the cutting part of the knife trajectory. 
     In an embodiment according to the system, the winding device is configured to rotate the base tube around the mandrel. 
     In an embodiment according to the system, the system comprises a tube support configured to hold the base tube in the knife trajectory. 
     In an embodiment according to the system, the tube direction is parallel to the centre axis. 
     In an embodiment according to the system, the base tube comprises a longitudinal tube axis extending parallel to the centre axis. 
     In an embodiment according to the system, the mandrel comprises a longitudinal mandrel axis extending in line with the tube direction. 
     In an embodiment according to the system, the strip supplying device is configured to supply paper strips and the winding device is configured to helically wind the paper strips around the mandrel. 
     In an embodiment according to the system, the strip supplying device is configured to supply only paper strips. 
     In an embodiment according to the system, the system comprises a controller having a first communication connection with the winding device and a second communication connection with the knife displacement drive, and the controller is configured to control the tube speed with which the base tube moves away from the mandrel and the rotational knife speed with which the knife is, when viewed in direction of the centre axis, moved along the virtual circle. 
     In an embodiment according to the system, the controller comprises a third communication connection with the knife rotation drive and the controller is configured to control the rotational cutting speed with which the knife rotates around its rotation axis by adjusting the rotation of the knife rotation gear ring about the knife rotation ring centre. 
     In an embodiment according to the system, the cutting device is configured to move a cutting area of the knife (or the knives) along the knife trajectory. 
     It will be clear that any combination of the features of any number of the above defined embodiments of the system can be made. 
     The invention further relates to a method for producing lengths of tube, such as drinking straws, with a system according to the invention, said method comprising supplying strips with the strip supplying device to the winding device and helically winding said strips around the mandrel to form a base tube moving away from the mandrel at a tube speed, cutting the base tube at a predetermined length with the cutting device while the base tube is moving in a tube direction at the tube speed and the knife of the cutting device is moved along the cutting part of the knife trajectory, and driving the first displacement unit and the second displacement unit with the knife displacement drive to move the knife, when viewed in the direction of the centre axis, along the virtual circle at a rotational knife speed and to move the knife over at least part of the knife axial distance in the tube direction at an axial knife speed equal to the tube speed when the knife moves along the cutting part of the knife trajectory and cuts the base tube. 
    
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
       Embodiments of the system and method according to the invention will be described by way of example only, with reference to the accompanied schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which; 
         FIG.  1 A  schematically shows a front view of an embodiment of the system according to the invention, 
         FIG.  1 B  schematically shows the front view of  FIG.  1 A  without the strips and the base tube, 
         FIG.  2    schematically shows an enlarged view of part II of  FIG.  1 A , 
         FIG.  3 A  schematically shows a side view of the system of  FIG.  1 A , 
         FIG.  3 B  schematically shows the view of  FIG.  3 A  without the strips and the base tube, 
         FIG.  4    schematically shows a rear view of the system of  FIG.  1 A , 
         FIG.  5    schematically shows a view in perspective of the cutting device of the system of  FIG.  1 A , 
         FIG.  6    schematically shows a view in perspective of the inside of the cutting device of  FIG.  5   , 
         FIG.  7    schematically shows a view in perspective of internal parts of the cutting device of  FIG.  5   , 
         FIG.  8    schematically shows a view in perspective of further internal parts of the cutting device of  FIG.  5   , 
         FIG.  9 A  schematically shows a top view in the direction of the centre axis of the knives and tube support of the cutting device of  FIG.  5   , 
         FIG.  9 B  schematically shows the top view of  FIG.  9 A  without the tube support, 
         FIG.  10    schematically shows a side view of the knives and tube support of  FIG.  9 A , 
         FIG.  11    schematically shows a further side view of the knives and tube support of  FIG.  9 A , 
         FIG.  12 A  schematically shows a further top view in the direction of the centre axis of the knives and tube support of the cutting device of  FIG.  5   , 
         FIG.  12 B  schematically shows the top view of  FIG.  12 A  without the tube support, 
         FIG.  13 A  schematically shows a side view of the knives and tube support of  FIG.  12 A , 
         FIG.  13 B  schematically shows the side view of  FIG.  13 A  without the tube support, 
         FIG.  14 A  schematically shows a further side view of the knives and tube support of  FIG.  12 A , 
         FIG.  14 B  schematically shows the side view of  FIG.  14 A  without the tube support, 
         FIG.  15 A  schematically shows a view in perspective of the knife trajectory of the cutting device of  FIG.  5   , 
         FIG.  15 B  schematically shows a side view of the knife trajectory of  FIG.  15 A , 
         FIG.  15 C  schematically shows a further side view of the knife trajectory of  FIG.  15 A , 
         FIG.  16    schematically shows an alternative embodiment of the system according to the invention, wherein the cutting device comprises one knife and one counterweight, and 
         FIG.  17    schematically shows a view in perspective of the positioning device of the system of  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The  FIGS.  1 - 4    show views of an embodiment of the system  1  according to the invention. Said system  1  is configured to perform the method according to the invention. 
     The system  1  comprises a mandrel  4 , a winding device  5  for helically winding strips  2  around the mandrel  4  to form a base tube  6  moving away from the mandrel  4  at a tube speed v t  (meter/second), a strip suppling device  7  for supplying the strips  2  to the winding device  5 , a cutting device  8  for cutting the base tube  6  at a predetermined length l t  to form the lengths of tube  3  while the base tube  6  is moving in a tube direction  9  at the tube speed v t , and a positioning device  80  for positioning the cut lengths of tube  3 . The system  1  comprises a support frame  110 . 
     The supplying device  7  supplies a first strip  2 A, a second strip  2 B and a third strip  2 C. The first strip  2 A is moved along a wax unit  64  configured to provide a layer of wax onto a contact side of the first strip  2 A. During the helically winding of the strips  2  around the mandrel  4 , the contact side of the first strip  2 A will be in contact with the mandrel  4 . The layer of wax functions as a lubrication between the mandrel  4  and the first strip  2 A. 
     During the helically winding, the second strip  2 B and the third strip  2 C are not in direct contact with the mandrel  4 . The second strip  2 B is moved along a first adhesive unit  65 A to apply a layer of adhesive to the second strip  2 B so that it will adhere to the first strip  2 A. The third strip  2 C is moved along a second adhesive unit  65 B to apply a layer of adhesive to the third strip  2 C so that it will adhere to the second strip  2 B. This way the base tube  6  is formed. 
     The first, second and third strips  2 A-C are paper strips  2 . The strip supplying device  7  is configured to supply only paper strips  2  and the winding device  5  is configured to helically wind the paper strips  2  around the mandrel  4 . In other embodiments of the system  1 , the strip supplying device  7  may be configured to (also) supply strips  2  made from a different material, such as one or more plastics. 
     The mandrel  4  has an elongate form defining a longitudinal mandrel axis  44  extending in line with the tube direction  9 . 
     The winding device  5  comprises a first winding roller  61  and a second winding roller  62  located at opposite sides of the mandrel  4 . The first winding roller  61  is rotatable about a first roller axis  71  and the second winding roller  62  is rotatable about a second roller axis  72 . A winding belt  63  extends around the first winding roller  61  and the second winding roller  62 . The winding belt  63  is wound around the mandrel  4 . The winding device  5  comprises a winding drive  60  operatively coupled to the first winding roller  61  for rotation about the first roller axis  71  as shown by the first rotation arrow  73 . This will cause a movement of the winding belt  63  around the mandrel  4  and around the second roller axis  72  of the second winding roller  62  as indicated by the second rotation arrow  74 . The winding belt  63  will helically wind the strips  2  around the mandrel  4  to form the base tube  6  moving along and away from the mandrel  4  at the tube speed v t . The base tube  6  comprises a longitudinal tube axis  49 . Due to the winding movement of winding belt  63 , the base tube  6  rotates around its longitudinal tube axis  49 . 
     The system  1  comprises a controller  50  having a first communication connection  51  with the winding device  5 , more specifically with the winding drive  60  of the winding device  5 . 
     The cutting device  8  comprises a knife displacement drive  42  and a knife rotation drive  35  (for more details see  FIG.  5   ). The knife displacement drive  42  is connected to the controller  50  via a second communication connection  52 . The knife rotation drive  35  is connected to the controller  50  via a third communication connection  53 . 
     The positioning device  80  comprises a positioning wheel  83  which is rotatable about a positioning axis  82  and configured to place a vertically extending length of tube  3  in a horizontal position. The positioning device  80  comprises a positioning drive  81  which is connected to the controller  50  via a fourth communication connection  54 . 
     The cutting device  8  is shown in detail in  FIG.  5   . The base tube  6  enters the cutting device  8  via a support tube  89  while moving with the tube speed v t  in the tube direction  9 . The knife displacement drive  42  comprises a knife displacement gear wheel  45  which is operatively coupled with a knife displacement gear ring  38  via a knife displacement belt  46 . The knife displacement gear ring  38  comprises first outer threads  37  (see also  FIG.  6   ). The knife rotation drive  35  comprises a knife control gear wheel  47  which is operatively coupled with a knife control gear ring  36  via a knife control belt  48 . The knife control gear ring  36  comprises second outer threads  39  (see also  FIG.  6   ). 
     In order to protect users against the knives  10 , the cutting device  8  comprises a cutting housing  100 . The cutting housing  100  comprise a control housing part  97  and a knife housing part  99 . The control housing part  97  is attached to the knife control gear ring  36  in order to rotate along with the knife control gear ring  36 . The knife housing part  99  is not fixated to the knife control gear ring  36  or the control housing part  97 , due to which the knife housing part  99  is able to rotate relative to the knife control gear ring  36  and the control housing part  97 . The knife housing part  99  is attached to the knife displacement gear ring  38  in order to rotate along with the knife displacement gear ring  38 . 
       FIG.  6    shows the inside of the cutting device  8 . The knife housing part  99  has been removed and the knife control gear ring  36  and the control housing part  97  are shown in a cross sectional view. The cutting device  8  comprises four knives  10  which are movable along a knife trajectory  11  surrounding a centre axis  12  and extending over a knife axial distance d ak  along the centre axis  12  (see also the  FIGS.  9  and  10   ). In other embodiments of the system  1 , the cutting device  8  comprises only one knife or two, three or five or six knives  10 . 
     The knife trajectory  11  forms, when viewed in a direction  15  of the centre axis  12 , a virtual circle  13  having a knife radius distance r k  and a circle centre  14  coinciding with the centre axis  12  (see also  FIG.  9 A ). The knife trajectory  11  comprises a cutting part  17  in which the knives  10  are moved over the knife axial distance d ak  in the tube direction  9  while, when viewed in the direction  15  of the centre axis  12 , moving along the virtual circle  13 . The knife trajectory  11  further comprises a retrieving part  18  in which the knives  10  are moved over the knife axial distance d ak  and opposite to the tube direction  9  while, when viewed in the direction  15  of the centre axis  12 , moving along the virtual circle  13  (see also  FIG.  9 B ). The cutting device  8  is configured to cut the base tube  6  with the knives  10  moving along the cutting part  17  of the knife trajectory  11  (see also the  FIGS.  12 A and  12 B ). 
     The cutting device  8  comprises a first displacement unit  19  configured to displace the knives  10  around the centre axis  12  and, when viewed in the direction of centre axis  12 , along the virtual circle  13  and a second displacement unit  20  configured to displace the knives  10  over the knife axial distance d ak  in the tube direction  9  and opposite thereto. A knife displacement drive  42  which is operatively coupled to the first displacement unit  19  and the second displacement unit  20  and configured to move the knives  10 , when viewed in the direction  15  of the centre axis  12 , along the virtual circle  13  at a rotational knife speed ω k  (cycles/min)—see also  FIG.  9 A —and to move the knives  10  over at least part of the knife axial distance d ak  in the tube direction  9  at an axial knife speed v k  (meter/second) equal to the tube speed v t  when the knives  10  move along the cutting part  17  of the knife trajectory  11  and cuts the base tube  6  (see also  FIG.  13 A ). 
     In this system  1 , the knives  10  of the cutting device  8  extend over a relatively short distance in the tube direction  9 . As a result, the system  1  is relatively shorter in the tube direction  9 . 
     The configuration of the cutting device  8  allows that the cutting device  8  creates a relatively more accurate cut in the base tube  6 . 
     The configuration of the cutting device  8  also allows that the cutting device  8  operates at a relatively higher speed. 
     This is amongst others caused by the specific movement of the knives  10  along the knife trajectory  11 . 
     Besides the function of cutting the base tube  6 , the knives  10  have the function of acting as counterweights  40 . In other embodiments of the system  1 , the cutting device  8  may comprise a different type of counterweight  40  which is movable along the knife trajectory  11  or at a counterweight  40  trajectory at a constant counterweight  40  distance from the knife trajectory  11  to balance the movement of the knives  10  along the trajectory. 
       FIG.  16    shows the inside of a cutting device  8  of an alternative embodiment of the system  1 . It differs from the embodiment of the  FIG.  1 - 14    in that the cutting device  8  comprises only one knife and one counterweight  40  (not being a knife). 
     The first displacement unit  19  and the second displacement unit  20  are configured to continuously displace a same number of knives  10  along the cutting part  17  of the knife trajectory  11  as displaced along the retrieving part  18  of the knife trajectory  11 . 
     The first displacement unit  19  comprises knife supports  29  holding the knives  10  at the knife radius distance r k  from the centre axis  12 , while allowing movement of the knives  10  over the knife axial distance d ak  parallel to the centre axis  12 . The first displacement unit  19  is configured to rotate the knife supports  29  around the centre axis  12 , while holding the knives  10  at the knife radius distance r k  from the centre axis  12 . The knife supports  29  are attached to the knife displacement gear ring  38  to move along with the knife displacement gear ring  38 . Each knife support comprises two support beams  90  extending parallel to the centre axis  12  and a knife slider  91  which is movable along the support beams  90 . The knives  10  are rotatably attached to the knife sliders  91  via a rotation beam  92 . 
     The second displacement unit  20  comprises cams  31  attached to the knives  10  and a cam track  32  configured to displace the knives  10  over the knife axial distance d ak  parallel to the centre axis  12  in the tube direction  9  when the knives  10  move along the cutting part  17  of the knife trajectory  11  and to move the knives  10  over the knife axial distance d ak  parallel to the centre axis  12  and opposite to the tube direction  9  when the knives  10  move along the retrieving part  18  of the knife trajectory  11 . The cam track  32  is shown in more detail in  FIG.  8   . 
     The knives  10  are rotating knives  33  having a rotation axis  34  extending parallel to the centre axis  12 . The knives  10  are operatively attached to a knife rotation gear wheel  93  surrounding the rotation axis  34 . The cutting device  8  comprises a knife rotation gear ring  94  engaging the knife rotation gear wheels  93  of the knives  10  and having a knife rotation ring centre  98  coinciding with the centre axis  12 . The knife rotation gear ring  94  comprises inner threads  95 . The knife rotation gear wheels  93  and the knife rotation gear ring  94  cooperate to rotate the knives  10  about their rotation axis  34  when the knives  10  are, when viewed in the direction  15  of the centre axis  12 , moved along the virtual circle  13 . The knife rotation gear ring  94  is rotatable about the knife rotation ring centre  98  and the cutting device  8  comprises a knife rotation drive  35  configured to rotate the knife rotation gear ring  94  about the knife rotation ring centre  98  in order to adjust a rotational cutting speed ω c  (cycles/minute) with which the knives  10  rotate around their rotation axis  34 . The knife rotation gear ring  94  is attached to the control housing part  97  in order to move along with the control housing part  97 . This way, the control housing part  97  has the function of a control connector  96  which operatively couples the knife rotation gear ring  94  and the knife control gear ring  36  driven by the knife rotation drive  35 . The knife rotation gear ring  94  is shown in more detail in  FIG.  7   . 
     The controller  50  is connected with the knife rotation drive  35  via the third communication connection  53 . The controller  50  is configured to control the rotational cutting speed ω c  with which the knives  10  rotate around their rotation axis  34  by adjusting the rotation of the knife rotation gear ring  94  about the knife rotation ring centre  98 . 
     The controller  50  is connected to the winding device  5  via the first communication connection  51  and to the knife displacement drive  42  via the second communication connection  52 . The controller  50  is configured to control the tube speed v t  with which the base tube  6  moves away from the mandrel  4  and the rotational knife speed ω k  with which the knife is, when viewed in direction  15  of the centre axis  12 , moved along the virtual circle  13 . 
     The predetermined length l t  of the lengths of tube  3  produced by the system  1  is determined by the tube speed v t  with which the base tube  6  moves away from the mandrel  4  and the rotational knife speed ω k  with which the knife is, when viewed in direction  15  of the centre axis  12 , moved along the virtual circle  13 . When a desired predetermined length l t  of the lengths of tube  3  is reached, the system will operate in practice with a constant tube speed v t  and knife speed ω k . 
       FIG.  9 A  shows a top view in the direction  15  of the centre axis  12  of the knives  10  and the tube support  41  of the cutting device  8  shown in  FIG.  5   .  FIG.  9 B  shows the top view of  FIG.  9 A  without the tube support  41 .  FIG.  10    shows a side view of the knives  10  and the tube support  41  of  FIG.  9 A .  FIG.  11    shows a further side view of the knives  10  and the tube support  41  of  FIG.  9 A . 
     The tube support  41  is configured to hold the base tube  6  in the knife trajectory  11 . The tube direction  9  extends parallel to the centre axis  12 . The longitudinal tube axis  49  of the base tube  6  extends parallel to the centre axis  12 . 
     The cutting part  17  of the knife trajectory  11  starts at a cutting part starting position  21  on the knife trajectory  11  and ends at a cutting part ending position  22  on the knife trajectory  11 . The retrieving part  18  of the retrieving trajectory starts at a retrieving part starting position  23  on the knife trajectory  11  and ends at a retrieving part ending position  24  on the knife trajectory  11 . The retrieving part ending position  24  and cutting part starting position  21  coincide, and the cutting part ending position  22  and the retrieving part starting position  23  coincide. The knife trajectory  11  has, when viewed in a transverse direction  16  extending perpendicular to the centre axis  12 , an oval-like shape. 
     The knives  10  are, when viewed in the direction  15  of the centre axis  12 , located at an equal distance d ck  from each other along the virtual circle  13 . The cutting part  17  and the retrieving part  18  of the knife trajectory  11  are, when viewed in the direction  15  of the centre axis  12 , located at opposite sides of the virtual circle  13 . The cutting part  17  of the knife trajectory  11  has a cutting part length l cp , the retrieving part  18  of the knife trajectory  11  has a retrieving part length l rp , and the retrieving part length l rp  is equal to the cutting part length l rp . 
     In the situation shown in the  FIGS.  9 - 11   , the fourth knife  10 D is about to start to move along the cutting part  17  of the knife trajectory  11  and has an axial knife speed v k-a  equal to the tube speed v t  and in the tube direction  9 . The first knife  10 A is located halfway the cutting part  17  of the knife trajectory  11 . The second knife  10 B is about to start to move along the retrieving part  18  of the knife trajectory  11 . The third knife  10 C is located halfway the retrieving part  18  of the knife trajectory  11 . The third knife  10 C is located halfway the retrieving part  18  of the knife trajectory  11  and has an axial knife speed v k-c  equal to the tube speed v t  and opposite to the tube direction  9 . 
       FIG.  12 A  shows a further top view in the direction  15  of the centre axis  12  of the knives  10  and tube support  41  of the cutting device  8  of  FIG.  5   .  FIG.  12 B  shows the top view of  FIG.  12 A  without the tube support  41 .  FIG.  13 A  shows a side view of the knives  10  and tube support  41  of  FIG.  12 A .  FIG.  13 B  shows the side view of  FIG.  13 A  without the tube support  41 .  FIG.  14 A  shows a further side view of the knives  10  and tube support  41  of  FIG.  12 A .  FIG.  14 B  shows the side view of  FIG.  14 A  without the tube support  41 . 
     In the situation shown in the  FIGS.  12 - 14   , the knives  10  are moved a bit further along the knife trajectory  11  when compared with the  FIGS.  9 - 11   . The first knife  10 A is moving along the cutting part  17  of the knife trajectory  11  and is located closer to the cutting part ending position  22  than to the cutting part starting position  21 . The first knife  10 A is cutting the base tube  6  and extends through part of the base tube  6 . In other words, the first knife  10 A is moved through part of the base tube  6 . More specifically, a cutting area  43  of the first knife  10 A is moved through part of the base tube  6 . Since the winding device  5  is configured to rotate the base tube  6  around the mandrel  4 , the base tube  6  rotates around its longitudinal tube axis  49 . Due to this rotation of the base tube  6 , the first knife  10 A extending through part of the base tube  6  creates a complete cut separating a length of tube  3  having a predetermined length l t  from the base tube  6 . The first knife  10 A has an axial knife speed v k-a  equal to the tube speed v t  and in the tube direction  9 . This means that when the first knife  10 A is cutting the base tube  6 , the first knife  10 A and the base tube  6  have the same speed in the tube direction  9 . This ensures that the first knife  10 A creates an accurate cut, even though the first knife  10 A during the cutting of the base tube  6  also moves, when viewed in the direction  15  of the centre axis  12 , along the virtual circle  13  at the rotational knife speed ω k . 
     The second knife  10 B is moving along the retrieving part  18  of the knife trajectory  11  and is located closer to the retrieving part starting position  23  than to the retrieving part ending position  24 . The third knife  10 C is moving along the retrieving part  18  of the knife trajectory  11  and is located closer to the retrieving part ending position  24  than to the retrieving part starting position  23 . The fourth knife  10 D is moving along the cutting part  17  of the knife trajectory  11  and is located closer to the cutting part starting position  21  than to the cutting part ending position  22 . The first knife  10 A and the fourth knife  10 D have an axial knife speed v k-a , v k-d  equal to the tube speed v t  and in the tube direction  9 . The second knife  10 B and the third knife  10 C have an axial knife speed v k-b , v k-c  equal to the tube speed v t  and opposite to the tube direction  9 . All the knives  10  move, when viewed in the direction  15  of the centre axis  12 , along the virtual circle  13  at the rotational knife speed ω k . 
       FIG.  15 A  shows a view in perspective of the knife trajectory  11  of the cutting device  8  of  FIG.  5   . The  FIGS.  15 B and  15 C  show side views of the knife trajectory  11 .  FIG.  15 B  shows a side view in the direction of the arrow  26  shown in  FIG.  15 C .  FIG.  15 C  shows a side view in the direction of the arrow  16  shown in the  FIGS.  9 B and  15 B . 
       FIG.  16    shows an alternative embodiment of the system  1  according to the invention. The cutting device  8  comprises only one knife  10  and one counterweight  40  not being a knife. 
       FIG.  17    shows a view in perspective of the positioning device of the system of  FIG.  1   . The positioning device  80  is configured to position the cut lengths of tube  3  in a horizontal position. The positioning wheel  83  receives the cut lengths of tube  3  and rotates them in a horizontal position on a conveyor belt  27 . 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention. 
     The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention. 
     It will be apparent to those skilled in the art that various modifications can be made to the system and method shown in the accompanied schematic drawings without departing from the scope as defined in the claims.