Add roller for a fiber placement machine
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. A method for operating 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 surface has a feed surface width, the method comprising, clamping the fiber tow against the feed surface of the feed roller using an add roller, of the add roller apparatus, having a width greater than the tow width and configured for bearing at least partially against the feed roller when the add roller is clamping the fiber tow against the feed surface of the feed roller.
2. The method of claim 1 , 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, and the method further comprises, clamping the add roller with sufficient clamping force to cause the pliable peripheral surface of the add roller to conform over the fiber tow and achieve driving contact with the feed surface of the feed roller.
3. The method of claim 2 , wherein, the fiber tow has a tow thickness thereof, and the add roller comprises a protruding flange thereof, extending outward from a peripheral surface of the add roller, for contacting the feed surface of the feed roller alongside of the fiber tow, and the method further comprises, placing the protruding flange into driving contact with the feed surface of the feed roller.
4. The method of claim 3 , wherein, the protruding flange has a height thereof substantially equal to, or greater than, the tow thickness.
5. The method of claim 3 , wherein the add roller apparatus includes an add roller actuator, having the add roller operatively attached thereto for selectively clamping the add roller against the feed roller, and the method further comprises, selectively operating the add roller actuator for clamping the add roller against the feed roller.
6. The method of claim 5 , further comprising:
mounting a plurality of add roller actuators, with each add roller actuator having an add roller attached thereto, in an add roller mounting frame adapted for removable attachment to the fiber placement head, to form an add roller module;
mounting the add roller module in the fiber placement head; and
selectively operating one or more of the plurality of add roller actuators for clamping one or more of the add rollers, of the plurality of actuators, against the feed roller.
7. The method of claim 1 , 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, and the method further comprises, placing the protruding flange into driving contact with the feed surface of the feed roller.
8. The method of claim 7 , wherein, the protruding flange has a height thereof substantially equal to, or greater than, the tow thickness.
9. The method of claim 1 , wherein the add roller apparatus includes an add roller actuator, having the add roller operatively attached thereto for selectively clamping the add roller against the feed roller, and the method further comprises, selectively operating the add roller actuator for clamping the add roller against the feed roller.
10. The method of claim 9 , further comprising:
mounting a plurality of add roller actuators, with each add roller actuator having an add roller attached thereto, in an add roller mounting frame adapted for removable attachment to the fiber placement head, to form an add roller module;
mounting the add roller module in the fiber placement head; and
selectively operating one or more of the plurality of add roller actuators for clamping one or more of the add rollers, of the plurality of actuators, against the feed roller.
11. The method of claim 1 , wherein:
the fiber placement head further comprises, a compaction roller defining a nip point movable along a tow placement path to a location along the tow placement path at which the tow is to be added;
the fiber placement machine further comprises a control arrangement, for anticipating the addition of a tow by the add roller and initiating clamping of the tow against the surface of the feed roller prior to the nip point reaching location along the fiber placement path at which the tow is to be added; and
the method further comprises, initiating clamping of the fiber tow against the surface of the feed roller prior to the nip point reaching location along the fiber placement path at which the tow is to be added.