Abstract:
A mandrel for the winding of wire includes a central element and segments radially extending about and respectively coupled to the central element by rotatable arms that permit the segments to assume a collapsed position and an extended position Inner surfaces of the segments define slots in which ends of the arms extend. One segment also defines a radially extending groove on an outer surface of that segment which intersects with the slot of that segment to define an opening through the segment. A resilient pad is fixed in the slot of that segment and has a face located at the opening and adjacent a surface of an arm coupling that segment to the central element. A wire is threaded into the opening and held in place when the arms are rotated to cause the segments to assume the extended position. Methods using the mandrel are disclosed.

Description:
BACKGROUND OF THE INVENTION 
     1. Field 
     The subject disclosure relates to mandrels. More particularly, the subject disclosure relates to a mandrel that grabs and holds wires or filaments to the mandrel around which the wire or filament is wound. 
     2. State of the Art 
     U.S. Pat. No. 2,634,922 to Taylor describes the winding of flexible wire, cable or filamentary material (hereinafter “wire”, which is to be broadly understood in the specification and claims) around a mandrel in a figure-eight pattern such that a package of material is obtained having a plurality of layers surrounding a central core space. By rotating the mandrel and by controllably moving a traverse that guides the wire laterally relative to mandrel, the layers of the figure-eight pattern are provided with aligned holes (cumulatively a “pay-out hole”) such that the inner end of the flexible material may be drawn out through the payout hole. When a package of wire is wound in this manner, the wire may be unwound through the payout hole without rotating the package and without kinking This provides a major advantage to the users of the wire. 
     Over the past fifty-plus years, improvements have been made to the original invention described in U.S. Pat. No. 2,634,922. For example, U.S. Pat. No. 5,470,026 to Kotzur describes means for controlling the reciprocating movement of the traverse with respect to the rotation of the mandrel in order to wind the filamentary materials on the mandrel to form a radial payout hole having a substantially constant diameter. In addition, over the past fifty-plus years, an increasing number of different types of wires with different characteristics are being wound using the systems and methods described in U.S. Pat. No. 2,635,922 and the subsequent improvements. For example, the figure-eight type winding has been used for Category 5 type cable, drop cable, fiber-optic cable, electronic building wire (THHN), etc. Despite the widespread applicability of the technology, challenges remain in applying the technology to different wires. 
     SUMMARY OF THE INVENTION 
     This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. 
     In one embodiment, a mandrel useful for winding wire thereabout is provided with a central element and a plurality of radially attached bowed segments that are movable from a first collapsed position where the segments are closer to the central element and to each other to a second expanded or extended position where the segments are further from the central element and are spaced further from each other. One or more movable arms couple each segment to the central element in order to move the segments back and forth between the first and second positions, and the segments each define at least one horizontal interior slot in which the arm of that segment is accommodated as it rotates into the first collapsed position. At least one of the segments is provided with a radially extending groove that extends radially across a substantial portion of the bowed segment along the outer surface of the segment. The radially extending groove intersects the interior slot, thereby providing an opening from the exterior of that segment to the interior of that segment. A resilient pad is fixed in the slot of the segment provided with the radial groove and is located adjacent the opening where the slot and groove intersect. The arm of the segment is located so that when the arm is an extended position, the arm either contacts the resilient pad or is within a distance of less than a diameter of a wire that is to wound around the mandrel. When the arm is rotated towards a collapsed position, the arm moves away from the resilient pad. 
     In one aspect, with the provided arrangement, the end of a wire that is to be wound around the mandrel can be inserted from the radial groove side into the opening defined by the radial groove and the slot of the segment when the segment is in its collapsed position. The segment may then be moved into its extended position, and the wire will be squeezed between the resilient pad and the arm and will extend along the radial groove until it reaches the surface of the segment. The wire can then be wound around the mandrel by placing the central element on a motor shaft, and running the motor which rotates the mandrel, and by controllably moving a traverse that guides the wire laterally relative to mandrel. When a desired length of wire is wound, the package on the mandrel can be removed from the mandrel by cutting the wire (if necessary), collapsing the mandrel from its extended position into the collapsed position, thereby releasing the wire from between the resilient pad and the arm, and lifting the package off of the mandrel. 
     In one aspect, the provided mandrel is particularly useful with brittle wire. 
     In one embodiment, the resilient pad is fixed in the slot by attaching the pad to a non-resilient support element that is fixed in the slot. The non-resilient support element may be a metal spacer that is screwed onto the segment. In one embodiment, the metal spacer may be movable in the slot to a plurality of different locations and then fixed at a desired one of the plurality of different locations. 
     In one embodiment, the slot mandrel segments are curved in two directions so that the segments form a barrel-shaped form. 
     Additional aspects of the subject disclosure will become evident to those of ordinary skill in the art upon reference to the drawings, specification, and claims hereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of a mandrel in an expanded position with a wire retainer. 
         FIG. 2  is a front view of the mandrel of  FIG. 1  in an expanded position. 
         FIG. 3  is a cross-sectional view through the mandrel of  FIG. 1  in an expanded position. 
         FIG. 4  is a partially exploded view of the mandrel of  FIG. 1  in an expanded position. 
         FIG. 5  is an exploded back view of a segment of the mandrel of  FIG. 1 . 
         FIG. 6  is a perspective view of the mandrel of  FIG. 1  in a collapsed position. 
         FIG. 7  is a cross-section view of the mandrel of  FIG. 1  in a collapsed position. 
         FIG. 8  is a partial side view of the mandrel of  FIG. 1  in an expanded position with a wire extending from an opening therein. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A mandrel  10  with a wire retainer is seen in  FIGS. 1-7 . Mandrel  10  is shown with a central hollow cylindrical element  15  and a plurality of radially attached segments  20  (one shown as  20 X). While six segments are shown, it will be appreciated that fewer or more segments could be utilized. Each segment is shown with an outer surface  22  that is bowed out (convex) in two directions. Each segment is also shown with an inner surface  23  that is concave in at least one direction. Each segment is coupled to the central element  15  via at least one arm or rod  25  (one shown as  25 X in  FIGS. 3 and 5 ). In the shown embodiment, two rods are used for each segment. Each of the rods define holes  30  that receive pins  32  that extend into bushings  34  located in corresponding holes  36  in the segment  20  and into corresponding holes (not shown) of the central element  15 . Set screws  37  may be used to help hold the pins in the bushings. As a result, the arms may rotate around the pins and cause the segments  20  to rotate from a first collapsed position ( FIGS. 6 and 7 ) where the segments are closer to the central element  15  and to each other, to a second expanded or extended position shown in  FIGS. 1-4  where the segments are further from the central element and are spaced further from each other. In the first collapsed position, the segments may touch each other or be very closely adjacent each other. In the first collapsed position, the segments take the shape of a bumpy barrel. In the second expanded or extended position seen in  FIGS. 1-4 , the segments are spaced from one another and their outer surfaces  22  appear at any cross-section to define a circle, although again, the circle may be slightly bumpy. Although not shown, a lock may be provided to keep the segments in the expanded position and/or in the collapsed position. 
     As shown in  FIGS. 1-4 , in the expanded position, the arms  25  are substantially perpendicular to the segments  20  and to the central element  15 . In one embodiment, in the collapsed position, the arms assume an angle of between substantially 10 degrees and 30 degrees relative to the segments and relative to the central element. For purposes herein, the term “substantially” when used with reference to an angle means plus or minus ten degrees. 
     As seen best in  FIG. 3 , the central element  15  is provided with a plurality of radially displaced slots  52  defined along an exterior surface of the central element to accommodate rotation of the arms  25  at least partially down into the slots during movement of the mandrel  10  into the collapsed position. The slots  52  may be called “horizontal” slots, although direction is relative, so that for purposes herein, “horizontal” and “vertical” are to be considered the same. However, both may be compared to “radial” which is different. It will be appreciated that the pins  32  extend across the slots  52 . 
     Also as seen best in  FIG. 3 , each segment  20  is provided with a horizontal slot  55  defined along the inner surface of the segment to accommodate rotation of the arms  25  ( 25 X) at least partially down into the slot  55  during movement of the mandrel into the collapsed position. Again, pins  32  extend across slot(s)  55 . 
     As seen in  FIGS. 1-5 , at least one of the segments (notated  20 X) is provided with a radially extending groove  60  that extends radially across a substantial portion of the bowed segment along the outer surface  22  of the segment. The radially extending groove  60  has a portion that is deep enough to transversely intersect the interior slot  55 , thereby providing an opening  65  (seen in  FIGS. 3 and 7 ) through that segment from the exterior of that segment to the interior of that segment. A resilient pad  70  is attached to a (non-resilient, e.g., metal) support element  75  and fixed in the slot  55  of the segment using a screw, bolt or rivet  77  extending through the support element  75  and into the segment  20 . The resilient pad  70  is positioned relative to the opening  65  so that a face  78  of the pad  70  is adjacent the opening  65 . The resilient pad  70  may be attached in any manner to the support element, such as by glue. 
     As seen best in  FIG. 3 , an arm (notated  25 X) attaching segment  20 X to the central element  15  is located so that a surface  25   a  of the arm  25 X is adjacent the pad  70 . More particularly, the arm of the segment is located so that when the arm is an extended position, the surface  25   a  of arm  25 X either contacts the face  78  of the resilient pad  70  or is within a distance of less than a diameter of a wire that is to be wound around the mandrel. In one embodiment, the surface  25   a  of arm  25 X is within a distance of half a diameter of a wire that is to be wound around the mandrel. When the arm  25 X is rotated towards a collapsed position, the surface  25   a  of the arm  25 X moves away from the face  78  of the resilient pad  70 . 
     In one embodiment, arms  25  have ends  25   b  that are rounded in one direction with the rounded ends of the arms defining the holes  30 . In one embodiment, as seen in  FIGS. 3 and 5 , one end  25   c  of arm  25 X extends past hole  30  to provide surface  25   a.  In one embodiment, surface  25   a  is flat. In one embodiment, seen best in  FIG. 3 , the horizontal slot  55  of segment  20 X is extended at  55   a  to accommodate the extended end  25   c  of arm  25 X and permit rotation thereof. 
     In one aspect, the mandrel  10  may be of any size. By way of example and not by way of limitation, the mandrel may have a diameter of 10 inches at the middle, 8.5 inches at the top and bottom (or right and left sides), and the segments may be between 8 and 8.5 inches long. 
     In one aspect, the resilient pad  70  may be made of any resilient material. By way of example and not by way of limitation, the resilient pad  70  may be made of rubber or synthetic rubber. In one aspect, the resilient pad  70  may be of any thickness and any height provided it fits inside the slot  55  defined in the inner side of the segment  20 X. By way of example and not by way of limitation, a rubber pad may be between 0.0625 and 0.5 inches thick and between 0.25 and 0.5 inches high. 
     In one aspect, the opening  65  defined by the radially extending groove  60  and the slot  55  may be of any reasonable size provided it will accommodate the wire material that is extending therethrough. By way of example and not by way of limitation, for a wire of between 0.04 inches and 0.1 inches in diameter the opening may be between 0.375 inches and 0.75 inches long and between 0.15 and 0.35 inches wide. 
     In one aspect, the radially extending groove  60  may have a flat bottom profile such that the groove is deeper in the middle (where it forms the opening  65  with the slot  55 ) and tapers as it extends radially to where it stops on each side. With such an arrangement, only a portion of the groove  60  forms an opening  65  with the slot  55 . The remainder of the groove permits a wire  100  (seen in  FIG. 8 ) to angle radially out of the opening  65 , into the groove  60  and then onto the outer surface  22  of the segment  20 X. 
     In one aspect, the width of the groove  60  can be approximately twice the width of the wire  100  being wound the mandrel, or smaller, but is larger than the diameter of the wire  100 . 
     In one aspect, with the provided mandrel  10 , the end of a wire  100  that is to be wound around the mandrel can be inserted from the radial groove side into the opening  65  defined by the radial groove  60  and the slot  55   a,    55  of the segment  20 X when the segment is in its collapsed position. The segment may then be moved into its extended position, and the wire will be squeezed (pinched) between the resilient pad  70  and the contact surface  25   a  of arm  25 X and will extend along the radial groove  60  until it reaches the surface  22  of the segment  20 X. The wire  100  can then be wound around the mandrel by placing the central element  15  on a motor shaft (not shown), fixing the mandrel to the shaft using a set screw  94  extending through a hole  96  of the central element (seen in  FIG. 4 ), running the motor which rotates the mandrel, and by controllably moving a traverse (not shown) that guides the wire laterally relative to mandrel  10 . When a desired length of wire is wound, the wire package on the mandrel  10  can be removed from the mandrel  10  by cutting the wire  100  (if necessary), collapsing the mandrel  10  from its extended position into the collapsed position, thereby releasing the wire  100  from between the resilient pad  70  and the arm  25 X, and lifting the package off of the mandrel  10 . 
     In one aspect, the provided mandrel is particularly useful with brittle wire. 
     In one embodiment, the metal spacer  75  to which the resilient pad  70  is fixed in the slot  55  of segment  20 X is movable in the slot to a plurality of different locations and then fixed at a desired one of the plurality of different locations. 
     In one embodiment, the slot mandrel segments are curved in two directions so that the segments form a barrel-shaped form. 
     There have been described and illustrated herein several embodiments of an mandrel with a wire retainer and a method of using the same. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while a mandrel with a particular number of segments has been disclosed, it will be appreciated that the mandrel could have a different number of segments. Also, while each segment is shown as being connected to the central cylinder by two arms, it will be appreciated that a different number of arms could be utilized. In addition, while particular angles of movement have been disclosed, it will be understood that the segments can move through different angles of movement. Further, while a hollow cylindrical central element is shown, it will be appreciated that the central element may assume different shapes. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.