Cable binder application device having a concentric drive motor

Abstract

A high-speed binder application device for wrapping binder material about a bundle of buffer tubes that encase a plurality of optical fibers includes a pair of opposite facing binder heads mounted on a pair of hollow shafts, each shaft being driven in rotation by a concentric drive motor mounted about the shaft. Each binder head includes a light-weight synthetic guide drum that dispenses binder material off a reel and onto the bundle of buffer tubes as it is advanced through the hollow shafts. The concentric mounting of the drive motors on the shafts eliminates shaft bending loads from drive belt tension and reduces vibrations at higher rotational speeds relative to belt-driven systems. The light weight and high strength of the synthetic guide drums allows the drums to be rotated at speeds in excess of 4000 RPM.

That which is claimed:  
     
         1 . A high-speed binder device for binding together various components of a cable advancing in a machine direction, said device comprising: 
 a frame;    a hollow shaft defining a central opening through which the cable is advanced, said hollow shaft being rotatably supported on at least two bearings that are spaced apart in the machine direction and mounted to said frame;    a binder reel supported on said shaft and having a supply of binder wound on the binder reel;    a guide drum supported on said shaft for paying out binder from the binder reel and wrapping the binder around the cable; and    a rotary drive comprising; 
 a stator fixed to said frame so as to surround said shaft, and  
 a rotatably driven rotor fixed to said rotatable shaft concentrically thereabout and within said stator so that, when said rotary drive is operated, the shaft with the guide drum mounted thereon is caused to rotate such that binder is unwound from the binder reel and wrapped around the advancing cable.  
   
     
     
         2 . A high-speed binder device as defined in  claim 1 , wherein said rotary drive comprises an electric drive motor, the stator comprising a coil.  
     
     
         3 . A high-speed binder device as defined in  claim 2 , wherein the electric drive motor comprises a variable-speed motor.  
     
     
         4 . A high-speed binder device as defined in  claim 1 , wherein said guide drum comprises a composite material.  
     
     
         5 . A high-speed binder device as defined in  claim 4 , wherein said guide drum comprises carbon fiber.  
     
     
         6 . A high-speed binder device as defined in  claim 1 , wherein said rotary drive is mounted between two bearings.  
     
     
         7 . A high-speed binder device as defined in  claim 1 , wherein the guide drum and the rotary drive are mounted on opposite sides of one of the bearings.  
     
     
         8 . A high speed binder device as defined in  claim 1 , wherein the guide drum defines an upstream end and a downstream end and the guide drum is rotatably supported on said shaft at only one of said ends.  
     
     
         9 . A high speed binder device as defined in  claim 1 , further comprising a second hollow shaft supported by at least two additional bearings, a second binder reel supported on the second shaft, a second guide drum supported on the second shaft, and a second rotary drive mounted about the second shaft, the two hollow shafts being axially aligned end-to-end.  
     
     
         10 . A high-speed binder device as defined in  claim 9 , wherein each rotary drive is mounted between two bearings.  
     
     
         11 . A high speed binder device as defined in  claim 10 , wherein each guide drum and the rotary drive therefor are located on opposite sides of one said bearing.  
     
     
         12 . A high-speed binder device as defined in  claim 1 , further comprising a brake located between the guide drum and the rotary drive.  
     
     
         13 . A method for binding together a plurality of components of a cable at a high speed, said method comprising the steps of: 
 advancing the cable components through a hollow rotatable shaft, the shaft supporting a binder reel having a supply of binder wound thereon;    supporting a guide drum on the rotatable shaft and around the binder reel for paying out binder from the binder reel; and    rotationally driving the guide drum so that the binder is wrapped around the cable components at a high rate of speed, said driving step comprising: 
 mounting a stator having an electric coil around the rotatable shaft,  
 fixing a rotor to the rotatable shaft concentrically thereabout, and  
 energizing the electric coil to cause the rotor to rotate, thereby causing the rotatable shaft and the guide drum to rotate so that binder is unwound from the binder reel and wrapped around the advancing cable components to form a cable.  
   
     
     
         14 . A method as defined in  claim 13 , wherein said driving step comprises varying the rotational speed of the guide drum.  
     
     
         15 . A method as defined in  claim 13 , wherein said rotationally driving step comprises driving the guide drum at a rotational speed of at least 4,000 rpm.  
     
     
         16 . A method as defined in  claim 13 , wherein said rotationally driving step comprises driving the guide drum at a rotational speed of approximately 5,000 rpm.  
     
     
         17 . A method as defined in  claim 13 , wherein said rotationally driving step further comprises driving a guide drum comprised of a composite material.  
     
     
         18 . A method as defined in  claim 17 , wherein said rotationally driving step further comprises driving a guide drum comprised of carbon fiber.  
     
     
         19 . A method as defined in  claim 13 , further comprising the step of supporting the rotatable shaft on at least two bearings that are spaced apart.  
     
     
         20 . A method as defined in  claim 19 , wherein the stator and rotor are mounted between two bearings.  
     
     
         21 . A method as defined in  claim 20 , wherein said step of supporting the guide drum includes supporting the guide drum on an opposite side of one of the bearings from the stator and rotor.  
     
     
         22 . A method as defined in  claim 13 , wherein said guide drum defines an upstream end and a downstream end and said step of supporting the guide drum includes supporting the guide drum on said shaft at only one of said ends.  
     
     
         23 . A method as defined in  claim 13 , further comprising the steps of advancing the cable components through a second hollow rotatable shaft, the second shaft supporting a second binder reel having a supply of binder wound thereon, supporting a second guide drum on the second rotatable shaft and around the second binder reel, and rotationally driving the second guide drum including mounting a second stator having a second electric coil around the second rotatable shaft, fixing a second rotor to the second rotatable shaft concentrically thereabout, and energizing the second electric coil to cause the second rotor to rotate, thereby causing the second rotatable shaft and the second guide drum to rotate so that binder is unwound from the second binder reel and wrapped around the advancing cable components to form the cable.  
     
     
         24 . A method as defined in  claim 23 , further comprising the step of supporting each rotatable shaft on at least two bearings spaced apart.  
     
     
         25 . A method as defined in  claim 24 , wherein the stator and rotor are mounted between two bearings.  
     
     
         26 . A method as defined in  claim 25 , wherein the steps of supporting the first and second guide drum include supporting each guide drum and the stator and rotor therefor on opposite sides of one said bearing.  
     
     
         27 . A method as defined in  claim 13 , further comprising a step of positioning a brake between the guide drum and the stator and rotor.