Abstract:
A system ( 12 ) for measuring geometry of a non-circular twisted strand ( 10 ) during a stranding process, the system comprising: a pulley ( 14 ), for being rotated by linear displacement of the strand ( 10 ) induced by the stranding process; a first encoder ( 16 ), for measuring the rotation of the pulley ( 14 ), thereby measuring the linear displacement of the strand ( 10 ); at least one embracing element ( 36 ), for embracing a vertex ( 38 ) or another zone ( 48 ) of the strand ( 10 ), for being rotated perpendicular ( 60 ) to the longitudinal position ( 58 ) of the strand ( 10 ), the embracing obtained by the non-circular character of the strand ( 10 ) rather than by friction, thereby allowing sliding the at least one embracing element ( 36 ) therealong; and a second encoder ( 20 ), for measuring the rotation of the at least one embracing element ( 36 ), thereby measuring the twist character of the strand ( 10 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to the field of strand processing. More particularly, the invention relates to a method and apparatus for measuring the geometry of a non-circular twisted strand during the stranding process. 
       BACKGROUND ART 
       [0002]    Ropes and cables are constructed of helical strands. The strand shape/cross-section/profile can be circular or non-circular. Typical non-circular strands include vertexes. 
         [0003]    The term “stranding process” refers herein to the manufacturing process of the strand. 
         [0004]    During the stranding process, geometrical parameters of the strand must be controlled and measured. The quality of the strand and of the rope is obtained accordingly. 
         [0005]    Geometrical parameters and features of the strand include: roundness and uniformity of the strand surface, critical dimensions of the strand shape, lay length of the twisted non-circular strand construction, any geometrical parameter that may impact the position of the strand when it is closed into the rope configuration, the final principal dimensions of the rope and the outer surface of the rope. 
         [0006]    Any anomaly/defect/fault generated during the stranding process of the strand may generate a critical anomaly anomaly/defect/fault at the rope level. The presence of anomaly/defect/fault at the rope level can cause the discarding of the rope during the rope closing process. Moreover, if the anomaly/defect/fault is not detected during the strand manufacturing process or at the rope closing process, the rope may be supplied to the customer defected. 
         [0007]    The anomaly/defect/fault can generate degradation/damage/interference to the rope performance and mechanical behavior. This can generate damage to the application, impacting the safety level, impacting the installation&#39;s performance and causing a considerable reduction in service life. 
         [0008]    There is a need for an online/real time procedure and system for the detection of geometrical anomalies/defects/faults, during the stranding process of non-circular and circular strands. 
         [0009]    This may avoid disqualification of the rope at the manufacturer or at the customer or end user side. The online/real time procedure and system for the detection, providing the quality assurance (QA), may eliminate manufacturing expenses. 
         [0010]    Thus, it is an object of the present invention to provide a method and system for measuring the geometry of the non-circular strand during the manufacturing thereof. 
         [0011]    It is another object of the present invention to detect defects during the stranding process. 
         [0012]    It is an object of the present invention to provide a solution to the above-mentioned and other problems of the prior art. 
         [0013]    Other objects and advantages of the invention will become apparent as the description proceeds. 
       SUMMARY OF THE INVENTION 
       [0014]    In one aspect, the present invention is directed to a system ( 12 ) for measuring geometry of a non-circular twisted strand ( 10 ) during a stranding process, the system comprising:
       a pulley ( 14 ), for being rotated by linear displacement of the strand ( 10 ) induced by the stranding process;   a first encoder ( 16 ), for measuring the rotation of the pulley ( 14 ) in relation to a stationary base ( 50 ), thereby measuring the linear displacement of the strand ( 10 );   at least one embracing element ( 36 ), for embracing a vertex ( 38 ) or another zone ( 48 ) of the strand ( 10 ), for being rotated perpendicular ( 60 ) to the longitudinal position ( 58 ) of the strand ( 10 ) upon the linear displacement thereof, due to the twist thereof, the embracing obtained by the non-circular character of the strand ( 10 ) rather than by friction, thereby allowing sliding the at least one embracing element ( 36 ) therealong; and   a second encoder ( 20 ), for measuring the rotation of the at least one embracing element ( 36 ) perpendicular ( 60 ) to the longitudinal position ( 58 ) of the strand ( 10 ) in relation to the stationary base ( 50 ),   thereby concurrent measurement of the linear displacement of the strand ( 10 ) and of the rotation of the at least one embracing element ( 36 ) provides a measurement of the twist character of the strand ( 10 ).       
 
         [0020]    The number of the at least one embracing elements ( 36 ) may comprise the number of vertexes ( 38 ) of the strand ( 10 ) designed to be produced by the stranding process,
   thereby each of the at least one embracing element ( 36 ) embraces one of the vertexes ( 38 ).   
 
         [0022]    The at least one embracing element ( 36 ) is shaped substantially complementary to a shape of the vertexes ( 38 ) of the strand ( 10 ) designed to be produced by the stranding process. 
         [0023]    The at least one embracing element ( 36 ) may comprise at least one pulley, for freely rotating along and upon the strand ( 10 ). 
         [0024]    The at least one embracing element ( 36 ) may comprise a springy element ( 28 ), for pressing the at least one embracing element ( 36 ) on the strand ( 10 ). 
         [0025]    The at least one embracing element ( 36 ) may comprise a plurality of embracing elements ( 36 ) surrounding the strand ( 10 ),
   thereby avoiding bending the strand ( 10 ).   
 
         [0027]    The system ( 12 ) may further comprise:
       at least one slideable surface sensor ( 40 ), for traveling together with the at least one embracing element ( 36 ), and for sliding along and attached to a zone ( 48 ) of the strand ( 10 ), for detecting deviations of a surface of the zone ( 48 ) from a pre-determined design of the stranding process.       
 
         [0029]    The at least one slideable surface sensor ( 40 ) may comprise a position measurement sensor, for detecting the deviations. 
         [0030]    The at least one slideable surface sensor ( 40 ) may comprise a brush element ( 62 ) for conducting electric signals from the at least one slideable surface sensor ( 40 ) to a stationary location ( 24 ). 
         [0031]    The system ( 12 ) may further comprise:
       a disk ( 32 ), connected to the at least one embracing element ( 36 ), for being rotated thereby perpendicular ( 60 ) to the longitudinal position ( 58 ) of the strand ( 10 ).       
 
         [0033]    The system ( 12 ) may further comprise:
       at least one springy element ( 28 ), for pressing the at least one embracing element ( 36 ) from the disk ( 32 ) onto the strand ( 10 ).       
 
         [0035]    The system ( 12 ) may further comprise:
       a wheel ( 18 ) disposed at a margin of the disk ( 32 ), for being rotated by the disk ( 32 ) via a gear system ( 46 ), wherein the wheel ( 18 ) is connected to the second encoder ( 20 ),   thereby the second encoder ( 20 ) is disposed away from a center of the disk ( 32 ).       
 
         [0038]    The system ( 12 ) may further comprise:
       a controller ( 24 ), for determining samples for the measurements,   thereby the measurements do not accumulate errors.       
 
         [0041]    The samples may comprise length segments, and/or angular segments. 
         [0042]    In another aspect, the present invention is directed to a method for measuring geometry of a non-circular twisted strand ( 10 ) during a stranding process, the method comprising the steps of:
       rotating a pulley ( 14 ) by linear displacement of the strand ( 10 ) induced by the stranding process;   measuring, by a first encoder ( 16 ), the rotation of the pulley ( 14 ), thereby measuring the linear displacement of the strand ( 10 );   embracing, by at least one embracing element ( 36 ), a vertex ( 38 ) or another zone ( 48 ) of the strand ( 10 ), for rotating the at least one embracing element ( 36 ) perpendicular ( 60 ) to the longitudinal position ( 58 ) of the strand ( 10 ) upon the linear displacement thereof, due to the twist thereof; and   measuring, by a second encoder ( 20 ), the rotation of the at least one embracing element ( 36 ) perpendicular ( 60 ) to the longitudinal position ( 58 ) of the strand ( 10 ),   thereby concurrent measurement of the linear displacement of the strand ( 10 ) and of the rotation of the at least one embracing element ( 36 ), provides a measurement of the twist character of the strand ( 10 ).       
 
         [0048]    The embracing of the vertex ( 38 ) or another zone ( 48 ) of the strand ( 10 ) may comprise free linear displacement of the strand ( 10 ) in relation to the at least one embracing element ( 36 ). 
         [0049]    The method may further comprise the steps of:
       rotating at least one slideable surface sensor ( 40 ) together with the at least two embracing elements ( 36 ); and   detecting by the at least one slideable surface sensor ( 40 ) deviations of a surface of the strand ( 10 ) from a pre-determined design of the stranding process,       
 
         [0052]    The method may further comprise the steps of:
       upon exceeding a pre-determined threshold of measurement, halting the standing process.       
 
         [0054]    The measurements may be conducted upon pre-determined samples of the strand ( 10 ),
       thereby the measurements do not accumulate errors.       
 
         [0056]    The reference numbers have been used to point out elements in the embodiments described and illustrated herein, in order to facilitate the understanding of the invention. They are meant to be merely illustrative, and not limiting. Also, the foregoing embodiments of the invention have been described and illustrated in conjunction with systems and methods thereof, which are meant to be merely illustrative, and not limiting. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0057]    Preferred embodiments, features, aspects and advantages of the present invention are described herein in conjunction with the following drawings: 
           [0058]      FIG. 1  is a perspective view of a strand scanner, according to one embodiment of the present invention. 
           [0059]      FIG. 2  is an enlarged view of the strand scanner of  FIG. 1 . 
           [0060]      FIG. 3  shows the strand scanner of  FIG. 1  having a cut in the strand, in order to demonstrate the strand twist and the rotation operated thereby. 
           [0061]      FIG. 4  shows a perspective view and an enlargement of the strand surface sensors  40  of  FIG. 3 . 
       
    
    
       [0062]    It should be understood that the drawings are not necessarily drawn to scale. 
       DESCRIPTION OF EMBODIMENTS 
       [0063]    The present invention will be understood from the following detailed description of preferred embodiments (“best mode”), which are meant to be descriptive and not limiting. For the sake of brevity, some well-known features, methods, systems, procedures, components, circuits, and so on, are not described in detail. 
         [0064]      FIG. 1  is a perspective view of a strand scanner, according to one embodiment of the present invention. 
         [0065]    A strand  10 , to be measured and examined by a strand scanner  12 , being a system for scanning strand  10 , according to one embodiment of the present invention, includes a plurality of wires  22  braided around a core  26 . The longitudinal core  26  is of a non-circular shape (not shown), e.g., triangular or oval shape, and is also twisted. Thus, strand  10  including wires  22 , surrounding longitudinal core  26 , as well is non-circularly shaped and also is twisted as shown in the figure. 
         [0066]      FIG. 1  shows a typical constitution of a non-circular strand  10 . The manufacturing of strand  10  is performed by a stranding machine, which is not shown in the figures. 
         [0067]    Strand scanner  12  according to the present invention may be disposed either at the front end of the machine (not shown) or at any independent disposition for measuring and examining the produced strand  10 . 
         [0068]    Strand scanner  12 , according to one embodiment of the present invention, provides an applicable solution for the need to measure critical geometrical parameters/features of the non-circular strand  10  profile, shape and surface thereof during the manufacturing of the strand  10 , together with measuring and detecting the specific anomalies/defect/faults along strand  10 , which might be generated during the stranding process. 
         [0069]    Thus, strand scanner  12  controls the quality of the manufacturing process of non-circular strand  10 . 
         [0070]    Strand scanner  12  is capable of examining strands  10  being produced as helical structures for wire ropes, cables and ropes applied for hoisting, mooring lines, communication lines, hauling, lifting, pulling, drilling, electrical conducting, tension member. Strands  10  are produced for having various non-circular shapes, configured to be linear and twisted, and constructed of rigid materials. 
         [0071]    Strand scanner  12  examines the external surface of strand  10 , and thus is capable of also examining strands  10  having various shapes, not limited to the above-mentioned description. 
         [0072]    Non-circular twisted strand  10  is continuously shifted into, therethrough, and out of scanner  12 , for being scanned thereby. During the scanning, strand  10  is examined regarding the twist extent, the distribution and the structure of strand  10 , including the width versus the length thereof, for identifying anomalies from the pre-determined design to be manufactured by the stranding machine, and for identifying defects. 
         [0073]    The term “shaft encoder” refers herein to an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analog or digital code. 
         [0074]    Strand scanner  12  counts the number of twists per length unit of strand  10 , by a shaft encoder  20  counting the number of rotations of a disk  32  in relation to the linear displacement of strand  10 , measured by a shaft encoder  16  counting the number of rotations of a linear motion pulley  14 . Shaft encoders  16  and  20  may be replaced by other encoders. 
         [0075]    In order to enable shaft encoder  20  be disposed away from the center of disk  32  and away from strand  10 , disk  32  may rotate another wheel  18 , via a gear system  46 . Wheel  18  is disposed at the margin of disk  32 , and wheel  18  is connected to rotation measurement shaft encoder  20 . The rotation measurement shaft encoder  20  provides an electrical signal  20 A corresponding to the rotation of wheel  18  thereof, and thus to that of disk  32 . 
         [0076]    A controller/computer  24  receives signal  20 A from the rotation measurement shaft encoder  20 . 
         [0077]    The linear displacement of strand  10  is measured by linear motion pulley  14 , having a known perimeter, thus each rotation thereof indicates the length of the perimeter. Linear motion pulley  14  may activate a wheel (not shown) of a linear displacement shaft encoder  16 . Linear displacement shaft encoder  16  provides an electrical signal  16 A corresponding to the rotation of linear motion pulley  14 . Controller/computer  24  receives a signal  16 A from linear displacement shaft encoder  16 . 
         [0078]    Linear motion pulley  14  functions as a linear displacement measurement system to measure the dynamical linear displacement of strand  10 . The linear displacement measurement system includes linear motion pulley  14  driven by strand  10 ; and linear displacement shaft encoder  16 , counting the rotations of linear motion pulley  14 . The linear displacement of strand  10  can be measured in real time. 
         [0079]    Controller/computer  24  receives signal  20 A from rotation measurement shaft encoder  20 , and signal  16 A from linear displacement shaft encoder  16 , and analyzes the two signals concurrently. 
         [0080]    Preferably, the analysis is performed at pre-determined linear segments, being locations on strand  10 , and/or at pre-determined angular segments, each segment being an examined sample, ranges thereof determined by controller  24 . 
         [0081]    For example, the linear displacement of strand  10  can be measured in specific pre-determined segments of the designed length of a cycle of twist, e.g., 42 centimeters, or a fraction thereof, e.g., 120 degrees. 
         [0082]    Controller/computer  24  typically provides an angular differential to a linear differential, the differentials in relation to the angle and the location of the last sample. According to the above example, the expected result may be 120 degrees per 14 centimeters. 
         [0083]      FIG. 2  is an enlarged view of the strand scanner of  FIG. 1 . 
         [0084]      FIG. 2  depicts three embracing elements  36  disposed around strand  10 , for embracing thereof. This embodiment of three embracing elements  36  is suited for a strand  10  having a triangular cross-section, depicted in the figures. The triangular cross-section includes a core  26  having a triangular cross-section, and wires  22  (not shown) braided around core  26 . 
         [0085]    The triangular cross-section comprises three vertexes  38 , namely A, B, and C indicated in  FIG. 3 , and each embracing element  36  embraces one vertex  38 . 
         [0086]    Since strand  10  is twisted, meaning that the angular position of the vertexes  38  changes therealong, as indicated in two locations in the figure, the linear motion of strand  10  is converted into a rotational motion of embracing elements  36  sliding thereupon strand  10 . Each embracing element  36  slides attached to the vertex  38  thereof upon strand  10 . 
         [0087]    According to another embodiment (not shown), each embracing element  36  embraces the flat surface  48  of strand  10 . 
         [0088]    A spring  28  and an adjusting screw  30  for adjusting the pressure of spring  28 , may press embracing element  36  onto vertex  38  thereof in relation to the cylinder  34 , or may allow to release the pressure therefrom, for getting free from one vertex, and for embracing another vertex  38 . This replacement of the vertex may be necessary for cases of defects in strand  10 . The pressure may be adjusted by adjusting screw  30  or by other means. 
         [0089]    A four embracing elements  36  construction (not shown) surrounding strand  10 , is suited for embracing a strand  10  having a quadrangular cross-section (not shown), for being rotated thereby. 
         [0090]    The number of embracing elements  36  surrounding strand  10 , the internal shape of embracing elements  36 , and the pressure of springs  28 , preferably are fitted to the expected vertex  38  or of the surface  48  of strand  10 , for efficiently embracing strand  10 , for being freely rotated thereby. In particular, embracing elements  36  preferably are shaped to be complementary to the shape of vertexes  38 . 
         [0091]    Embracing elements  36  function as shoes, and may constitute pulleys or skates being free to rotate for sliding along the linear direction of strand  10 , thus substantially being floating. 
         [0092]    The embracing of strand  10  by embracing elements  36  is obtained by the non-circular character of strand  10 , and not by friction force, such as by tight gripping. Vertexes  38 , even if not sharp, such as in an ellipse, constitute the non-circular character of strand  10 . Thus, the embracing of strand  10  by embracing elements  36  allows sliding embracing elements  36  along strand  10 . 
         [0093]    Embracing elements ( 36 ) substantially evenly surround strand  10 , thus they do not bend the strand. 
         [0094]    The twisted shape surface of the strand  10  rotates the three embracing elements  36  in direction  60  being perpendicular to the longitudinal position  58  of strand  10 . 
         [0095]    The cylinders  34  of embracing elements  36  are rigidly fixed to disk  32 . A piston  54  is movable within each cylinder  34 . Spring  28  presses piston  54  towards strand  10 . A fork  56  is rigidly fixed to piston  54 . Embracing element  36  is pivotally connected to fork  56 . Thus, rotation of embracing elements  36  perpendicular to strand  10  rotates disk  32 . 
         [0096]    Disk  32  rotates wheel  18 , being connected to rotation measurement shaft encoder  20  and from there to controller  24 . 
         [0097]    Linear motion pulley  14  is rotated by strand  10  due to friction therebetween, thus rotating the wheel (not shown) of linear displacement shaft encoder  16 . Linear displacement shaft encoder  16  is connected to controller  24 , thus measuring the linear displacement of the strand  10 . 
         [0098]    Thus, strand scanner  12  includes a dynamical mechanism including embracing elements  36  following and measuring the lay length of the non-circular twisted strand  10  and of the surface quality of the strand. 
         [0099]    The dynamical mechanism includes embracing elements  36  being radially disposed around the strand axis. Embracing elements  36  are preferably fitted to the profile of the expected strand  10 . For example: for triangular strand, there should be three individual embracing elements  36 . For oval or flat strands, there should be two individual embracing elements  36 . 
         [0100]    Embracing elements  36  are radially pressed by spring  28  or by any compression mechanisms which may ensure the optimal contact between embracing elements  36  and strand  10 . Accordingly, the linear movement of the twisted strand  10  is converted to a rotational movement of embracing elements  36  and thus of the disk  32 . 
         [0101]    Embracing elements  36  are made of steel or any rigid material. The material of the pulleys may fit the material of strand  10 , for avoiding damage to the strand surface, due to the radial compression. 
         [0102]    Disk  32 , being rigidly fixed to cylinders  34 , is rotated by embracing elements  36 , being rotated by strand  10 , in relation to a stationary base  50  via radial bearings (not shown). 
         [0103]    Linear motion pulley  14  is rotated by strand  10 , in relation to a rack and fork  52 , being fixed to base  50 . Rack and fork  52 , being fixed to base  50 , provide that linear motion pulley  14  fixed thereto, substantially does not measure the length of the twist along strand  10 . 
         [0104]    According to another embodiment, the linear motion of strand  10  may be measured by counting rotations of embracing elements  36 . This embodiment is not preferable since it measures the length of the twist along strand  10 . 
         [0105]    Base  50  may be fixed to the stranding machine (not shown) at the outlet stage/station thereof, i.e. close to the collecting spool of strand  10 , or may be disposed at a further location. 
         [0106]      FIG. 3  shows the strand scanner of  FIG. 1  having an imaginary cut in the strand, in order to demonstrate the strand twist and the rotation operated thereby. 
         [0107]    At the linear location where strand  10  exits the strand scanner  12 , vertexes  38  of strand  10  are marked in the figure at two different linear locations thereof, with letters A, B, and C. Due to the twisted shape of the strand  10  the position of the letters is rotated from one location to another. For example, the letter A at one location of the strand is rotated from the letter A at the other locations thereof. 
         [0108]    Cylinder  34  functions as a track for the spring  28  pressing embracing elements  36 . 
         [0109]    Strand scanner  12  may further include surface sensors  40  for measuring the texture of the “flat” surface  48  (shown in  FIG. 4 ) of strand  10 . For example, surface sensor  40  may indicate the presence of a protrusion at a certain area on flat surface  48 , being a defect. Any of surface sensors  40  may detect the defect and may stop the entire machine from processing the manufacturing of strand  10 . 
         [0110]      FIG. 4  shows a perspective view and an enlargement of the strand surface sensors  40  of  FIG. 3 . 
         [0111]    Each of surface sensors  40  ends with an end surface  42 . End surface  42  slides upon and along one of flat surfaces  48  of strand surface  10 . 
         [0112]    End surface  42  of surface sensor  40  rotates together with the disk  32  and embracing elements  36 , and thus the flat surface  48  of strand  10  is expected to be unchangeable during the scanning in spite of all the movements. Thus, any change is reported to be a defect in the surface of the strand  10 . 
         [0113]    The term “brush element” refers herein to a circular device for conducting electric current between stationary wires and moving parts, most commonly in a rotating shaft. 
         [0114]    Unlike rotation measurement shaft encoder  20  and linear displacement shaft encoder  16 , recording the direct rotation count of disk  32  and of linear motion pulley  14  respectively, the axle thereof being stationary, end surfaces  42  of surface sensors  40  are not stationary, since they rotate together with the disk  32  and with embracing elements  36 . Thus, a brush element  62  conducts the electric signals produced by surface sensors  40  to a stationary location, such as to controller  24  (not shown). 
         [0115]    Surface sensors  40  measure the surface roughness and principal dimensions of the twisted strand  10 . The measurement approves triangular attitude in the case of triangular strands, principal diameters in the case of oval and flat strands and any principal dimensions in non-circular strands  10 . 
         [0116]    Surface sensors  40  are disposed near embracing elements  36  and can be radially positioned to maintain an optimal contact with the strand circular shape. 
         [0117]    The term “LVDT” refers herein to a Linear Variable Differential Transformer, being an electrical transformer used for measuring linear displacement. 
         [0118]    Surface sensors  40  may be of any position measurements sensors, such as: LVDT, proximity magnetic, optical etc. 
         [0119]    Surface sensors  40  may rotate with disk  32  while following on the quality of the strand surface  48 , thus detecting anomaly thereon, such as upstanding wire, change in strand diameter, etc. 
         [0120]    Gear system  46  transmits the rotational displacement of disk  32  to a rotational motion of wheel  18 . Gear system  46  may constitute a belt gear system or a teeth gear system. 
         [0121]    A data acquisition system, which may be included in controller  24 , records the actual rotational position of the disk  32  and the strand linear displacement. The data acquisition system can be any PLC (Programmable Logic Controller) instrument or any computerized system with the appropriate software and A/D (Analog to Digital) or D/A systems. 
         [0122]    A computerized software application, programmed according to the expected characteristics of strand  10 , as produced by the stranding machine (not shown), and a specific measurement application, simultaneously calculate the local lay length/twist level of the strand by dividing the recorded data of the linear displacement of strand  10  by the rotational displacement of disk  32 . This can be conducted into individual segments. The size and level of segments is defined by the operator. 
         [0123]    For each segment, the program may divide the local measured rotational displacement of disk  32  by the local linear displacement of the strand  10 . Accordingly, the local twist/lay length is measured and calculated. The computerized software application calculates the main actual dimensions of the strand  10  as measured by the radial position sensors. 
         [0124]    A visual display (not shown) displays the local lay length of strand  10 . This visual display may plot the lay length/twist level of the strand versus the strand linear location. The visual display may include the upper and lower limits of the required twist level. 
         [0125]    An alarm element may execute a vocal alert generator or a red light activator. This alarm may be activated when the level of twist deviates from the required range. The alarm may be activated when any deviation is detected by the radial sensors. 
         [0126]    A shut down system may include an electrical connection to the electrical board of the stranding machine. When the alarm is activated due to over twist/low twist, anomaly at the surface, or fault in a principal strand dimension, the shutdown system may generate shut down of the stranding machine. 
         [0127]    The strand scanner  12  preferably is automatically operated during the stranding process. It is positioned proximate to the strand spool at the front of the stranding machine. 
         [0128]    The strand scanner  12  preferably is designed for heavy duty stranding operations, such as up to 5,000 meters continuous measurement. It is preferably designed for strand sizes, such as for a range of 5-25 mm triangular attitude, and of similar diameter for oval strands. The strand scanner  12  preferably requires simple and fast preparation for process. The local twist level of the strand may be measured at relatively very small segments, such as every 50 mm. 
         [0129]    In the figures and/or description herein, the following reference numerals (Reference Signs List) have been mentioned:
       numeral  10  denotes a strand to be examined;   numeral  12  denotes a system for scanning a strand, according to one embodiment of the present invention;   numeral  14  denotes a linear motion pulley, being a pulley for measuring linear motion of the strand;   numeral  16  denotes a shaft encoder, for measuring the linear displacement of the strand;   numeral  16 A denotes a signal;   numeral  18  denotes a wheel;   numeral  20  denotes a shaft encoder, for measuring the rotation of the disk;   numeral  20 A denotes a signal;   numeral  22  denotes a wire wrapped around the core of the strand;   numeral  24  denotes a controller;   numeral  26  denotes the core of the strand;   numeral  28  denotes a spring, for pressing the embracing element on the strand;   numeral  30  denotes a screw, for adjusting the pressure of the spring;   numeral  32  denotes a disk;   numeral  34  denotes a cylinder, for housing the spring;   numeral  36  denotes an embracing element, for embracing the strand, while sliding along the strand;   numeral  38  denotes a vertex of the strand;   numeral  40  denotes a surface sensor, for sensing a surface quality of the strand;   numeral  42  denotes an end surface of the surface sensor;   numeral  46  denotes a gear system;   numeral  48  denotes a flat surface of the strand;   numeral  50  denotes a base, being the stationary element, in relation to which the measurements are conducted;   numeral  52  denotes a rack and fork, being fixed to the base, and being rotatably connected to the linear motion pulley;   numeral  54  denotes a piston, for carrying the fork of the pulley;   numeral  56  denotes the fork of the pulley;   numeral  58  denotes the longitudinal position of the strand;   numeral  60  denotes the direction of motion of the disk;   numeral  62  denotes a brush element.       
 
         [0158]    The foregoing description and illustrations of the embodiments of the invention has been presented for the purposes of illustration. It is not intended to be exhaustive or to limit the invention to the above description in any form. 
         [0159]    Any term that has been defined above and used in the claims, should to be interpreted according to this definition. 
         [0160]    The reference numbers in the claims are not a part of the claims, but rather used for facilitating the reading thereof. These reference numbers should not be interpreted as limiting the claims in any form.