Abstract:
Disclosed herein is a flyer bow for use in a wire-twisting machine including a body with an airfoil shaped cross section, a recessed channel within the body and a series of wire guide inserts retained within the recessed channel. Further disclosed herein is a wire guide insert including a tubular body having an exterior non-circular shape corresponding to a similar non-circular shape of a channel and an exhaust opening in the wire guide inserts.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/657,998, filed on Mar. 2, 2005, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND  
       [0002]     This invention relates to flyer bows. Flyer bows for use on twisting machines are well known in the art. Twisting machines with flyer bows can be used to make twisted cables for a wide variety of uses. Flyer bows can be used with pairing, tripling, quadding, bunching and twisted machines for wires. A typical flyer bow is generally rectangular in cross section. Wires to be twisted pass longitudinally along the inside surface of the flyer bow and are guided along the surface through ceramic or metal wire guides. A groove or recessed channel in the inside surface of the flyer bow is often incorporated into the design of the flyer bow in order to nest the wires to be twisted close to the surface of the flyer bow. This configuration reduces drag on the wires due to wind that sweeps transversely across the flyer bow during use. Flyer bows with airfoil shapes have been successfully used to increase speed of the winding machines with the benefits of minimum power draw and reduced operational noise. However, the airfoil does little, if anything, to minimize the effect of drag on the exposed wires. Furthermore, the exposed wire guides create additional drag on the flyer bow as it rotates.  
         [0003]     An existing flyer bow is described in U.S. Pat. No. 6,223,513 B1, issued to Post et al. and assigned to Kamatics Corporation, the entire contents of which are incorporated herein by reference. U.S. Pat. No. 6,223,513 B1 discloses a flyer bow with an integral enclosed wire guide. This design reduces drag by incorporating the wire guide within the flyer bow.  
       BRIEF DESCRIPTION OF THE INVENTION (SUMMARY)  
       [0004]     Disclosed here in is a flyer bow for use in a wire-twisting machine including a body with an airfoil shaped cross section, a recessed channel within the body and a series of wire guide inserts retained within the recessed channel.  
         [0005]     Further disclosed herein is a wire guide insert including a tubular body having an exterior non-circular shape corresponding to a similar non-circular shape of a channel and an exhaust opening in the wire guide inserts. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     Referring now to the drawings wherein like elements are numbered alike in the several Figures:  
         [0007]      FIG. 1  is a front plan view of a conventional flyer bow.  
         [0008]      FIG. 2  is a cross section view of the flyer bow of  FIG. 1  taken at arrows  2 - 2 .  
         [0009]      FIG. 3  is a front plan view of a flyer bow depicting one embodiment of the present invention.  
         [0010]      FIG. 4  is a cross section view of the flyer bow of  FIG. 3  taken at arrows  4 - 4 .  
         [0011]      FIG. 5  is a cross section view of an alternate embodiment of the invention showing the wire guide insert in the hexagonal channel.  
         [0012]      FIG. 6  is a bottom plan view of a hexagonal wire guide insert.  
         [0013]      FIG. 7  is a front plan view of the wire guide insert of  FIG. 6 .  
         [0014]      FIG. 8  is a section view of the wire guide insert of  FIG. 7  taken at arrows  8 - 8 .  
         [0015]      FIG. 9  is an alternate embodiment with corrugated bumps on the inside diameter of the wire guide insert. 
     
    
     DETAILED DESCRIPTION  
       [0016]     Referring to  FIGS. 1 and 2 , a conventional flyer bow  10  includes a body  20 , the wire guides  30  and the recessed channel  21 . The recessed channel  21  and the airfoil shape of the body  20  illustrate conventional techniques incorporated to minimize the drag of the flyer bow  10  during operation of the twisting machine. Protrusion of the wire guides  30  outside the airfoil shape of the body  20  and into the air stream result in higher drag, less efficiency and more power consumption.  
         [0017]     Referring to  FIGS. 3 and 4 , in one embodiment of the invention the flyer bow  70  includes an aerodynamic airfoil shaped body  80  with a recessed hexagonal shaped channel  81 , without the use of wire guides that protrude into the air stream resulting in higher aerodynamic losses. In tests conducted on wire twisting machines, embodiments of the invention consumed 12.3% less power than a conventional steel body with exposed wire guides and 4.6% less power than a conventional composite airfoil shaped body with exposed wire guides. In addition to the extra power required to run the twisting machines (electric power costs) there was more noise.  
         [0018]     Referring to  FIG. 5 , an alternate embodiment illustrates the use of wire guide inserts  90 , that are retained completely within the airfoil shape of the body  80  in channel  81 . The hexagonal shape of the insert  90  matches that of channel  81  to prevent rotation of the insert  90  within the channel  81 , which maintains alignment of the insert opening  91 , as best depicted in  FIGS. 7 and 8 , with the channel opening  82 . Both the insert opening  91  and the channel opening  82  allow for egress of dust that is created by the wire  50  passing through the wire guide inserts  90  during operation of the twisting machine. This feature provides for a self-cleaning design and provides for a maintenance free feature so that the twisting machine does not have to be shut down to clear the dust that could clog the channel in the bow.  
         [0019]     Though a hexagonal shaped insert  90  and hexagonal channel  81  are depicted in this embodiment in  FIG. 5 , it should be understood that any non-circular shaped cross section that provides for anti-rotation of the insert  90  within the channel  81  (such as an ellipse, square, pentagon, octagon, etc.) could adequately serve this function without deviating from the present invention.  
         [0020]     The wire guide inserts  90  shown in  FIGS. 6 through 8  are assembled into channel  81  from either end of the body  80  in an end-to-end fashion. The wire guide inserts  90  abut each other along the channel  81  to maintain the position of the wire guide inserts  90  within the channel  81 . The wire guide inserts  90  at the ends of the body  80  are secured in position by a retainer (not shown).  
         [0021]     The wire guide inserts  90  can be constructed of any material that has a hard, wear resistant surface, to resist wear by the wire that passes through them. A partial material listing includes: steel, or steel that has had a surface plating or coating applied to it to increase the hardness such as titanium carbo-nitride (TiCN), titanium-nitride (TiN), electrolytic or electroless nickel plating, chrome plating, ceramic coatings, etc. The insert can also be made of nickel based alloys such as inconel, ceramic materials, plastic composites, etc.  
         [0022]     The wire guide inserts  100  as shown in  FIG. 9 , can also be shaped with an undulating interior surface  101 , that reduces the contact area with the wire  50  that passes through the inserts  100 , thereby decreasing the frictional forces and resulting drag on the wire.  
         [0023]     The body  80 , as shown in  FIG. 5 , can be constructed from composite material including but not limited to carbon fiber epoxy, fiberglass epoxy, aramid fiber epoxy, or a combination of two or three of the materials mentioned. The body  80  may be reinforced with a carbon fiber  85  material using a braided structure for the carbon fibers  85 . The use of a braided fiber  85  construction is also unique as this type of construction increases the strength of the body  80  and allows the body  80  to have increased damage tolerance and increased resistance to fractures due to impacts from wire  50  strikes. The wire  50  that passes through the wire twisting machine will at times break and the broken wire  50  can impact the body  80  which is rotating at a high speed in the machine. The braided fiber  85  construction is more resilient to wire  50  strikes and the braided fiber  85  construction works to arrest any cracks that may be initiated due to a wire  50  strike resulting in a longer body  80  life.  
         [0024]     Referring again to  FIG. 5 , the body  80  of the bow may also have hollow sections  86  to decrease the weight while increasing the stiffness and give it an I-beam geometric shape. The reduction of weight of the body  80  reduces the centrifugal pull on the airfoil body  80  attachment ends. The hollow sections  86  can also be filled with foam  87  to further increase stiffness of the body  80  without adding significantly to the weight of the body  80 . The thicker section that is provided by the use of an airfoil section to contain the wire guide inserts  90  and the wire  50  internally, also produces a stiffer airfoil cross section. This stiffer cross section enables the body to keep its as manufactured curved shape  120  even under the high centrifugal loads that are imposed on the body when it is spinning in the wire twisting machine as is depicted in  FIG. 10 . Conventional designs with thinner cross sections tend to produce an irregular shape  130  and tend to flatten at the apex of the bow while rotating. The result of the irregular shape  130  is that the wire makes greater contact with the wire guides and degrades the quality of the wire due to the abrasion by the greater contact area and force.  
         [0025]     While preferred embodiments have been shown and described, various modifications and substitutions maybe made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.