Patent ID: 8512024

Claim:
A device comprising: a first motor having a first axis extending in a first direction; a second motor having a second axis extending in a second direction opposite the first direction, the second axis parallel to and overlapping with the first axis; a first gear rigidly coupled to the first axis, the first gear having a first concave, toothed portion around a first perimeter thereof; a second gear rigidly coupled to the second axis at a first position axially offset from the first gear, the second gear having a second concave, toothed portion around a second perimeter thereof; a first bearing rotatably coupled to the first axis at a second position axially aligned with the second gear of the second axis, thereby forming a channel between the first bearing and the second gear to receive and move a first filament by rotation of the second motor; and a second bearing rotatably coupled to the second axis at a third position axially aligned with the first gear of the first axis, thereby forming a second channel between the second bearing and the first gear to receive and move a second filament by rotation of the first motor.