Add Roller for a Fiber Placement Machine

Abstract

An apparatus and invention are provided for accelerating an added tow to match the lay-down speed of other tows exiting a compaction roller of a fiber placement head, by driving the added tow with an add roller operatively coupled to be driven at the same peripheral speed as a feed roller having a peripheral speed matching the peripheral speed of the compaction roller.

1 . An add roller arrangement for an automated fiber placement machine, comprising:
 a feed roller having a feed surface;   an add roller for clamping a fiber tow to the feed surface, the add roller having an outer radial peripheral surface; and   wherein the add roller has an engaged position relative to the feed roller in which the add roller is in bearing contact with the feed roller, the add roller forming a tow channel at least when the fiber tow is clamped between the feed roller and the add roller.   
   
   
       2 . The add roller arrangement of  claim 1 , wherein the tow channel is defined by the add roller including at least one flange extending from the peripheral surface, the tow channel defined between the feed surface, the peripheral surface, and the at least one flange, the at least one flange providing a bearing contact with the feed roller. 
   
   
       3 . The add roller arrangement of  claim 2  wherein the outer radial peripheral surface of the add roller is pliable such that when the fiber tow is clamped to the feed roller by the add roller the at least one flange is formed. 
   
   
       4 . The add roller arrangement of  claim 3  wherein the at least one flange includes a pair of flanges, the pair of flanges each extending between an exterior edge and an interior edge of each of the pair of flanges, wherein the exterior edge of each of the pair of flanges is in spaced relation along the add roller and is located at axial extremities thereof, and wherein the interior edge of each of the pair of flanges is in opposed spaced relation and thereby define a tow channel width. 
   
   
       5 . The add roller arrangement of  claim 1  further comprising an add roller actuator operably connected to the add roller, the add roller actuator operable to drive the add roller between the engaged position and a raised position. 
   
   
       6 . The add roller arrangement of  claim 2  wherein the pliable outer radial peripheral surface of the add roller is configured to form a pair of radially extending flanges when the fiber tow is clamped to the feed roller. 
   
   
       7 . The add roller arrangement of  claim 1  wherein a rotation of the feed roller results in a rotation of the add roller at the same peripheral speed when the add roller is in the lowered position. 
   
   
       8 . The add roller arrangement of  claim 5  further comprising a control arrangement, the control arrangement operably connected to the actuator to govern the timing of an actuation of the actuator. 
   
   
       9 . The add roller arrangement of  claim 8  further comprising a compaction roller, the compaction roller defining a nip point movable along a tow placement path to a location along the tow placement path at which a fiber tow is to be added, wherein the control arrangement signals the actuator to drive the add roller to the lowered position such that the fiber tow is clamped to the feed roller prior to the nip point reaching the location along the tow placement path where the fiber tow is to be added. 
   
   
       10 . The add roller arrangement of  claim 1  further comprising a mounting frame, and a plurality of actuators and a plurality of add rollers attached to the mounting frame, the mounting frame configured for modular attachment to a fiber placement head. 
   
   
       11 . An add roller apparatus, for clamping a fiber tow against a feed surface of a feed roller of a fiber placement head of an automated fiber placement machine, wherein the fiber tow has a tow width extending between first and second longitudinal edges of the tow and the feed roller has a feed surface having a width greater than the tow width, the add roller apparatus comprising, a feed roller having a width greater than the tow width and configured for simultaneously bearing against the feed roller adjacent at least one of the longitudinal edges of the tow when the feed roller is clamping the fiber tow against the feed surface of the feed roller. 
   
   
       12 . The add roller apparatus of  claim 11 , wherein, the add roller comprises a pliable peripheral surface thereof, conformable over the fiber tow, for simultaneously contacting both the fiber tow and the feed roller. 
   
   
       13 . The add roller apparatus of  claim 11 , wherein, the fiber tow has a tow thickness thereof, and the add roller comprises at least a first and a second protruding flange thereof, extending outward from the peripheral surface of the add roller and spaced apart a distance greater than the tow width, for contacting the feed surface of the feed roller alongside of both edges of the fiber tow. 
   
   
       14 . The add roller apparatus of  claim 13 , wherein, the protruding flanges have a height thereof extending above the peripheral surfaces of the add roller substantially equal to, or greater than, the tow thickness. 
   
   
       15 . The add roller apparatus of  claim 14 , wherein, the height of the protruding flanges is greater than the tow thickness, to thereby establish driving contact between the add roller and the feed surface of the feed roller, for rotationally accelerating the add roller prior to fully clamping the tow. 
   
   
       16 . An add roller apparatus, for clamping a fiber tow against a feed surface of a feed roller of a fiber placement head of an automated fiber placement machine, wherein the fiber tow has a tow width and the feed roller has a feed surface width greater than the tow width, the add roller apparatus comprising, an add roller having a width greater than the tow width but less than the feed surface width and configured for bearing at least partially against the feed surface of the feed roller when the add roller is clamping the fiber tow against the feed surface of the feed roller. 
   
   
       17 . The add roller apparatus of  claim 16 , wherein, the add roller comprises a pliable peripheral surface thereof, conformable over the fiber tow, for simultaneously contacting both the fiber tow and the feed roller. 
   
   
       18 . The add roller apparatus of  claim 17 , wherein, the fiber tow has a tow thickness thereof, and the add roller comprises a protruding flange thereof, extending outward from the peripheral surface of the add roller, for contacting the feed surface of the feed roller alongside of the fiber tow. 
   
   
       19 . The add roller apparatus of  claim 18 , wherein, the protruding flange has a height thereof substantially equal to, or greater than, the tow thickness. 
   
   
       20 . The add roller apparatus of  claim 19 , further comprising, an add roller actuator, having the add roller operatively attached thereto, for selectively clamping the add roller against the feed roller.