APPARATUS FOR MEASURING LENGTH OF YARN DRAWN OUT FROM WARP BEAM OF WARP KNITTING MACHINE

PURPOSE: To obviate the occurrence of hindrance even if an oscillation arm is reversed during operation of an apparatus for measuring the length of the withdrawn yarn which generates the yarn length signal corresponding to the length of the yarn drawn out of warp beam by driving a signal generator for generating the yarn length signal by bringing a pressure roll into pressurized contact with the winding yarn of the warp beam via an oscillation arm. CONSTITUTION: The pressure roll 11 is pivotally fitted to an oscillation arm and is disposed on a lever 13 pulled in the direction of the beam in such a manner that the lever 13 is rotated in the direction parting from the warp beam 4 when the roll 11 is kept pushed up and that the lever 13 is rotated in the direction toward the beam 4 when the roll is held lifted. A limit switch 31 disposed at the oscillation arm 14 is so manipulated that the switch 31 is closed in the state that the switch is held pressed by the lever 13 and that the switch 31 opens when the switch is held lifted. The switch 31 is operated to be opened while the roll 11 is still in contact with the beam 4 during turning of the lever 13 when the oscillation arm turns to the direction parting from the beam 4.