rollers 8 9 and 10 are rotatably driven by a drive device not shown disposed in the gear end 1 the above mentioned top arm section 6 includes a top frame 12 rotatably mounted to the roller stand 7 through a support rod 11 a front top roller 13 a second top roller 14 a back top roller 15 carried by a retainer housed in the top arm frame 12 and a hook 16 rotatably mounted on the top arm frame 12 by a pin 17 the engagement of the hook 16 with a pin 18 provided on the roller stand 7 causes the top rollers 13 14 and 15 to abut against the bottom rollers 8 9 and 10 under a predetermined surface pressure through a spring incorporated in the retainer the back top roller 15 is provided with a drive periphery 15a as shown in fig3 and 5 and upstream of the back rollers 10 and 15 a trumpet 19 for transporting fiber bundles to a predetermined position is attached to the support rod 11 of the roller stand 7 reference numeral 20 designates a clearer mechanism rotatably mounted on the top arm frame 12 and 21 designates a clearer frame.