Abstract:
The invention relates to a moving device for a coil core or a coil having a closed shape with an inner contour and an outer contour, including first and second rollers able to rotate around a respective axis and intended to bear against one of the two contours of the core or of the coil, means for driving at least one of said rollers in rotation, and retaining means associated with each roller, the retaining means being subject to first return means arranged to bring the first retaining means closer to the other of the two contours of the core or the coil, as well as a coil winder equipped with such a device.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a device for moving a coil core, or a coil having a closed shape with an inner contour and an outer contour, forward, and a coil winder equipped with such a device. 
       BACKGROUND 
       [0002]    Coil winders are used to make coils by winding a conductive wire, often made from copper and often electrically insulated by varnishing, around a ferromagnetic core, in particular made from soft iron. 
         [0003]    The coil, due to the geometry of the core, is closed on itself, thereby delimiting a passage opening. 
         [0004]    These coils can be applied by being included in the composition of Hall effect sensors. 
         [0005]    The principle of these sensors lies in the current variation created by the passage of a metal bar inside the passage opening of the coil. 
         [0006]    To that end, most of the time the coil of these sensors has a toroidal shape so as to allow the passage, in the opening thereof, of a round bar or a rectangular bar depending on the product families. 
         [0007]    However, for specific needs related to the bulk, it is necessary to miniaturize these sensors. Indeed, having a round bar passage affects the bulk of the sensor, which is a constraint for integrating sensors into increasingly compact systems. 
         [0008]    This miniaturization requires changing the toroidal shape of the coil of the sensor and therefore requires a coil winder capable of winding a conductive wire around a core having a non-toroidal shape. 
         [0009]    A coil winder used to wind a toroidal core comprises three rollers arranged around the core of the coil and coming into contact therewith. 
         [0010]    At least one of these three rollers is a driving roller and drives the core in rotation at a constant speed in order to allow a shuttle passing through the passage opening of the core to practically uniformly wind the conductive wire around the section of the core. 
         [0011]    This moving device is satisfactory for making coils with toroidal shapes, but is not intended to receive a core having another shape, in particular an oblong shape. 
         [0012]    Starting from existing elements of this moving device, first adaptations were done to try to perform winding on an oblong core. 
         [0013]    This adaptation consists of fixing the core, flat, along its primary plane, on an open plastic shim at the opening thereof in order to allow the passage of the shuttle. 
         [0014]    The shim is then placed between the three rollers, the spacing of which has been modified and moved in translation by at least one of them. 
         [0015]    However, the method for adapting the existing tool is tedious to carry out and has the major drawbacks of only being able to perform partial winding on the two lengths of the oblong core and causing an imbalance between these two wound parts. 
         [0016]    Document DE10146169A1 provides a solution for performing winding on a core having a non-toroidal shape, and in particular an oblong shape. 
         [0017]    This solution consists of using a belt to drive the core or coil in rotation. 
         [0018]    The belt is stretched by a set of rollers arranged carefully so that it partially grasps the core or the coil on its outer contour. 
         [0019]    However, this causes a modification of the position of the rollers or the use of a belt with a different length to wind cores with different sizes. 
         [0020]    Moreover, by using a belt, the rotational movement of the core created by the belt does not keep a constant distance between the shuttle and the core or the coil, which can cause distensions of the wire over certain portions of the coil, in particular on the curved portions of the core. 
         [0021]    As a result, the choice of this solution causes significant excess costs related to the purchase of this type of coil winder with a set of belts having different lengths and the preventive or curative maintenance thereof, in particular by replacing belts. 
       BRIEF SUMMARY 
       [0022]    The present invention aims to resolve all or some of the aforementioned drawbacks. 
         [0023]    To that end, the present invention relates to a moving device for a coil core or a coil having a closed shape with an inner contour and an outer contour, characterized in that it includes first and second rollers able to rotate around a respective axis and intended to bear against one of the two contours of the core or of the coil, means for driving at least one of said rollers in rotation, first retaining means associated with the first roller, the first retaining means being subject to first return means arranged to bring the first retaining means closer to the other of the two contours of the core or the coil, and second retaining means associated with the second roller, the second retaining means being subject to second return means arranged to bring the second retaining means closer to the other of the two contours of the core or of the coil. 
         [0024]    These arrangements make it possible to wind a core or a coil with non-toroidal shapes, in particular oblong shapes, while also making it possible to wind toroidal shapes. 
         [0025]    This device also grants the core or the coil a revolution movement keeping the shuttle at a substantially constant distance from the coil or the core, thereby reducing the risks of distension of the wire on the core or the coil. 
         [0026]    According to one embodiment, the retaining means are able to rotate around the axis of rotation of their respective roller. 
         [0027]    According to the same embodiment, the device comprises two arms associated with each roller and each comprising a body on which the retaining means and the return means are arranged, said arms including means allowing the rotation of the retaining means around the axis of their respective rollers. 
         [0028]    According to one embodiment, the retaining means can move in translation along an axis cutting the axis of rotation of their respective roller. 
         [0029]    According to the same embodiment, the device comprises two arms associated with each roller and each comprising a body on which the retaining means and the return means are arranged, said arms including means allowing the translation of the retaining means along an axis cutting the axis of rotation of their respective roller. 
         [0030]    According to one embodiment, at least one of the arms includes a guide means. 
         [0031]    This arrangement makes it possible to maintain an arm so as to prevent it from going askew and hindering the emptying of the wire from the shuttle during the movement of the core or the coil. 
         [0032]    According to the same embodiment, the two arms each include a means for adjusting the return means. 
         [0033]    This arrangement makes it possible to adjust the stiffness of the return means as a function of the thickness of the section of the core, but also as a function of the number of overlaps and turns of the coil to be made. 
         [0034]    According to the same embodiment, the body has a surface intended to ensure sliding contact of the first roller  4   a  or the second roller  4   b.    
         [0035]    According to one embodiment, the device comprises a support shim arranged on a fixed support and intended to ensure sliding contact of the core or the coil. 
         [0036]    This arrangement makes it possible to maintain the movement of the core or of the coil along a same plane perpendicular to the axis of rotation of the driving rollers. 
         [0037]    According to one embodiment, the driving means ensuring the rotational movement of at least one roller include a Cardan joint. 
         [0038]    The use of a Cardan joint eliminates, in the rotational driving movement of the driving roller, the lateral play that may be caused by a transmission by simple interlocking due to shape complementarity. 
         [0039]    According to one embodiment, the driving means include a system for adjusting the play. 
         [0040]    This arrangement makes it possible to eliminate the longitudinal play of the transmission that may be caused during rotation thereof and thus prevents a break in the transmission, which would result in winding several turns in the same location of the core or coil. 
         [0041]    According to the same embodiment, the system for adjusting the play includes at least one spring. 
         [0042]    The spring makes it possible to design an efficient adjustment system with a lower cost. 
         [0043]    According to one embodiment, a shim is used to raise the driving means in order to facilitate the movement thereof. 
         [0044]    This arrangement provides additional support to the driving means. 
         [0045]    The present invention also relates to a coil winder equipped with a moving device according to the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0046]    Other features and advantages of the invention will emerge from the detailed description below, considered in connection with the drawings, which illustrate, as an example, the principles of the invention. 
           [0047]      FIG. 1  illustrates the operation of a coil winder for a core or coil having a toroidal shape. 
           [0048]      FIG. 2  illustrates the operation of a coil winder equipped with a moving device according to the invention. 
           [0049]      FIG. 3  shows a top view of an arm used in the moving device according to the invention. 
           [0050]      FIG. 4  shows a bottom view of an arm used in the moving device according to the invention. 
           [0051]      FIG. 5  shows driving means used in the moving device according to the invention. 
           [0052]      FIG. 6  shows an exploded view of the driving means illustrated in  FIG. 5 . 
           [0053]      FIG. 7  shows an exploded view of a roller mounted on an arm. 
           [0054]      FIG. 8  shows the actuating portion driving the driving means. 
           [0055]      FIG. 9  shows a lateral view of an arm as well as driving means on which a driving roller is mounted. 
           [0056]      FIG. 10  is a top view of a support for an arm and a driving roller in a moving device according to the invention. 
           [0057]      FIG. 11  is a front view of a coil winder equipped with a moving device according to the invention. 
           [0058]      FIG. 12  shows a partial top view illustrating the operation of the arms according to the invention in a situation with a coil. 
           [0059]      FIG. 13  shows a partial side view illustrating the operation of the arms according to the invention in a situation with a coil. 
       
    
    
     DETAILED DESCRIPTION 
       [0060]    As illustrated in  FIG. 1 , a coil winder originally used to wind a core  3  or a coil  3 ′ with a toroidal shape and subsequently adapted to receive a moving device  1  according to the invention, comprises a shuttle  2  passing through a passage opening  6  of the core or coil  3 ′ and delivering a copper wire  5  to be wound around the core or the coil  3 ′ as well as three driving rollers  4   a ,  4   b  and  4   c.    
         [0061]    In the continuation of the description, the terms core  3  and coil  3 ′ may be used interchangeably to designate the piece on which the winding is done, the core  3  becoming a coil  3 ′ at the end of a first covering layer by the copper wire  5 . 
         [0062]    The three driving rollers  4   a ,  4   b  and  4   c  have a gripping surface placed in contact with the outer contour of the core  3  or the coil  3 ′ in order to drive the latter in rotation. 
         [0063]    The driving rollers  4   a  and  4   b  are arranged on either side of the shuttle  2 , while the third driving roller  4   c  is arranged facing the shuttle  2 . 
         [0064]    In order to drive the core  3  or the coil  3 ′ in rotation, only one of the three rollers needs to be a driver, the other two then being mounted freely rotating and serving only as a guide for the core  3  or the coil  3 ′. 
         [0065]    The shuttle  5  rotates at a constant speed at the same time as the three driving rollers  4   a ,  4   b  and  4   c  in order to position the turns of a same covering layer series regularly next to each other. 
         [0066]    As illustrated now in  FIG. 2 , a moving device of a coil  3 ′ core  3  or of a coil  3 ′ according to the invention only comprises the driving rollers  4   a  and  4   b  arranged on either side of the shuttle  2 . 
         [0067]    With the third driving roller  4   c , it is obvious that a core  3  or a coil  3 ′ with an oblong shape, like that illustrated in  FIG. 2 , could not be made to rotate due to the difference in the distance between the points of contact of the three rollers during rotation of the core  3  or of the coil  3 ′. 
         [0068]    In the moving device  1  according to the invention, the third roller  4   c  has been replaced by two arms  7   a  and  7   b  illustrated in detail in  FIGS. 3 and 4 . 
         [0069]    According to a first preferred embodiment, each arm  7   a ,  7   b  is arranged horizontally and made up of a body  9  having an oblong shape as well as a sliding contact surface  10  of the first roller  4   a  or the second roller  4   b . To that end, a flat washer  33 , visible in  FIG. 7 , is inserted between the sliding contact surface  10  and each of the rollers  4   a ,  4   b.    
         [0070]    Each of the rollers  4   a ,  4   b  includes a circumferential shoulder  30 . 
         [0071]    Each of these arms  7   a ,  7   b  also comprises an oblong through opening  11  formed by milling in the direction of the length of the body  9  of the arm  7   a ,  7   b  also with a substantially oblong shape. 
         [0072]    Inside said opening  11 , a return means  12  is placed materialized by a compression spring  12  bearing on one of its ends on an adjustment means  13  materialized in the form of an adjustable bolt passing through the body  9  and maintained by a nut. 
         [0073]    The length of the spring  12  and the adjustment of the adjusting means  13  reveal a passage  15  in the opening  11 . This passage  15  is intended for the insertion of an axis  17  of a driving roller  4   a ,  4   b . The action of the spring  12  maintains the arm  7   a ,  7   b  on the axis of the roller  4   a ,  4   b  in a plane substantially perpendicular thereto. 
         [0074]    To help this maintenance, the spring  12  can include a Teflon sleeve  35  partially inserted in the spring  12  and increasing the contact surface with the axis  17  of a driving roller  4   a ,  4   b . This sleeve  35  also serves as wearing ring and improves the sliding of the axis  17  of a driving roller  4   a ,  4   b  through the use of a Teflon metal contact. 
         [0075]    Each arm  7   a ,  7   b  also comprises a retaining means  8   a ,  8   b  extending transversely to the sliding contact surface  10  of the body  9  of the arm  7   a ,  7   b  and mounted freely rotating on a bearing  14  incorporated into the body  9 . 
         [0076]    At least one of the rollers  4   a ,  4   b  is driven in rotation by driving means  20 . Driving means  20  are illustrated in  FIG. 5 . 
         [0077]    Driving means  20  comprise three portions A, B, and C interlocking and sliding in each other. 
         [0078]    A first end of the portion A slides in the portion B and is kept at a distance therefrom by the action of a first compression spring  22  bearing on one hand on one end of the portion A and on the other hand on the bottom of a cavity formed in the portion B to guide the translation of that same end of the portion A. 
         [0079]    The portion B slides in the portion C and is kept at a distance therefrom by the action of a second compression spring  23  bearing on one hand on an annular shoulder at the base of one end of the portion B, and on the other hand on the bottom of a cavity formed in a first end of the portion C to guide the translation of that same end of the portion B. 
         [0080]    The portion C comprises a Cardan joint articulation  21  as well as a second cavity formed at its second end in which the axis  17  of a roller  4   a  or  4   b  is inserted. 
         [0081]    Each connection formed by one end of the portions A, B, C as well as the end  24  of the axis  17  of a driving roller  4   a ,  4   b  as well as by the different cavities formed in these different parts is ensured using devices with complementary shapes ensuring the blocking of the rotation between two adjacent portions and allowing the translation by sliding between two adjacent portions. 
         [0082]    These devices can indifferently be formed by flat sections, grooves, keys, or any other device known by those skilled in the art blocking the rotation without blocking the translation between two adjacent portions. It is also possible to consider only leaving one of the connections between two adjacent portions free in translation, in which case the other connections may be blocked in translation and in rotation by devices known by those skilled in the art, such as screws on nuts or pins. Translational and rotational blocking of the set of connections is also possible. 
         [0083]    The second end  25  of the portion A comprises a spherical head with two branches extending transversely from said spherical head. Thus, the head and its two branches form a T-shaped end  25 . 
         [0084]    This T-shaped end  25  is intended to be inserted into one of the three actuating cylinders  32  of the actuating portion  31  of the coil winder. 
         [0085]    By using a single actuator and a set of gears (not shown), the three actuating cylinders  32  rotate together at the same speed of rotation. 
         [0086]    To that end, each of the three actuating cylinders  32  comprises two notches  29  diametrically opposite each other and open on the top of the actuating cylinders  32  to be able to receive the branches of the “T” there formed on the end  25  of the portion A. 
         [0087]    The spherical head of the end  25  bears in the bottom of the actuating cylinders  32 . Teflon shims  26  are arranged in that same bottom in order to raise the driving means  20 . These shims  26  also serve as wearing shims through the use of a Teflon metal contact. 
         [0088]    Thus, a kinematic chain is made formed by an actuator, the three actuating cylinders  32 , the driving means  20 , and the driving rollers  4   a ,  4   b.    
         [0089]    As illustrated in  FIG. 7 , the axis  17  of a driving roller  4   a ,  4   b  comprises a circumferential shoulder  34  maintained in the passage  15  formed between the return means  12  and the body  9  of the arm  7   a ,  7   b . Each of the assemblies formed by a roller  4   a  or  4   b  with its axis  17  is then engaged in a passage  18  formed in the support  16 , which simultaneously supports the arms  7   a ,  7   b , the driving means  20 , and a driving roller  4   a ,  4   b . The diameter of the circumferential shoulder  34  is very slightly smaller than the width of the oblong opening  11  in order to maximally decrease the play between the arms  7   a ,  7   b  and the axis  17  of each of the rollers  4   a ,  4   b.    
         [0090]    As illustrated in  FIG. 10 , the support  16  comprises guide means  19  whereof a first portion is made up of a cylindrical element  19   a  protruding transversely from the face of the arm  7   a ,  7   b  coming against the support  16  and a second portion  19   b  is machined on the outer upper edge of the support near the passage  18 . 
         [0091]    These guide means  19  make it possible to limit the rotational and translational travel of the body  9  of the arm  7   a ,  7   b  during winding, and thereby prevent the body  9  from being in the recess area of the wire  5  of the shuttle  2 . 
         [0092]    Lastly, as shown in particular by  FIGS. 12 and 13 , a support shim  27  is arranged opposite the shuttle  2  in order to support the core  3  or the coil  3 ′ during revolution movement thereof. This support shim  27  comprises a retractable portion  28  so that it can adapt to cores  3  or coils  3 ′ with different heights. 
         [0093]    During the use of a coil winder equipped with a moving device  1  of a coil  3 ′ core  3  or of a coil  3 ′, the operator starts by introducing the core  3  into the shuttle  2  through its passage opening  6 . 
         [0094]    Then the operator places the core  3  or the coil  3 ′ flat on the shoulder  30  of the two rollers  4   a ,  4   b , between those same rollers  4   a ,  4   b  and the retaining means  8   a ,  8   b  as well as on the support shim  27  with or without the retractable portion  28  depending on the size of the core  3  or the coil  3 ′ to be wound. 
         [0095]    The retaining means  8   a ,  8   b  of each arm  7   a ,  7   b  continuously maintain a section of the core  3  or the coil  3 ′ respectively against the driving roller  4   a  or  4   b  through action of the return means  12 . To that end, the stiffness of the spring  12  can be adjusted by maneuvering the adjustment means  13 . 
         [0096]    The action of the return spring  12  simultaneously increases at the thickness of the section of the coil  3 ′ in the maintenance zones of the arms  7   a  and  7   b  due to the overlap of several turns of the coil  3 ′. 
         [0097]    The retaining means  8   a ,  8   b  are free in rotation on their bearing  14  with the result that when the shuttle  2  and the actuating portion  31  are started at the same time, the driving means  20  transmit a rotational movement to the driving rollers  4   a  and  4   b , which in turn drive the core  3  or the coil  3 ′ in a planar revolution movement. 
         [0098]    This movement keeps the core  3  or the coil  3 ′ at a substantially constant distance from the shuttle  2 . 
         [0099]    At the same time as this planar revolution movement, the coil winder winds the copper wire  5  around the section of the core  3  or of the coil  3 ′ located in the axis of the shuttle  2 , which results in uniformly distributing the turns on the core  3  or the coil  3 ′. 
         [0100]    During its revolution movement, the core  3  or the coil  3 ′ can drive a slight rotational movement of the arms  7   a  or  7   b  around the axis of the driving rollers  4   a ,  4   b  on which they are mounted. 
         [0101]    This slight rotational movement in turn drives a slight translational movement of the arms  7   a ,  7   b  and therefore of the retaining means  8   a ,  8   b  along the main axis of the oblong opening  11 . 
         [0102]    Indeed, if initially the points of contact of a driving roller  4   a  or  4   b  and their respective retaining means  8   a  or  8   b  are aligned along a straight section of the core  3  or of the coil  3 ′ corresponding to their minimum deviation, the rotation of an arm  7   a  or  7   b  modifies this alignment and therefore the distance between a driving roller  4   a  or  4   b  and its respective retaining means  8   a  or  8   b.    
         [0103]    The rotation of an arm  7   a  or  7   b  can be counterbalanced by the action of the operator, who brings the arm  7   a  or  7   b  back into alignment with the straight section of the core  3  or of the coil  3 ′. 
         [0104]    Although the invention has been described in connection with specific embodiments, it is obviously in no way limited thereto and encompasses all technical equivalents of the means described as well as combinations thereof if they are within the scope of the invention.