sley sword 5 and the reed 7 to swing forward and rearward at this time the pivot shaft 10 and the eccentric shaft 12 are located in the positions of the solid lines and therefore the reed 7 swings between the advance position af and the backdown position ab as shown in fig4 and 5 under this state beating up is made two times and thereafter the piston rod 15a of the hydraulic cylinder 15 is withdrawn by a timing of the next beating up thereby to shift the eccentric shaft 12 into the position shown in phantom this moves the eccentric shaft 12 upwardly so that the advance position bf largely shifts forward relative to the above mentioned advance position af in which the backdown position bb only slightly shifts forward relative to the backdown position bb under this state the reed 7 swings between the advance position bf and the backdown position bb accordingly at this time beating up is made at the advance position bf with two weft yarns beated up at the advance position af thus pile yarn projects in loop shape as same as in known pile fabric weaving looms during a time between this beating up and the next beating up the piston rod 15a of the hydraulic cylinder 15 is projected thereby to restore the eccentric shaft 12 into the position of the solid lines accordingly in this case weft picking is accomplished within a weft picking possible angle u03b8 formed between the reed 7 at the advance position.