SEWING MACHINE

• Main Authors: KUWABARA KOJI, NAKANO MOTONARI
• Format: Patent
• Language: English; Japanese
• Published: 07.09.2015
• Subjects: EMBROIDERING; SEWING; TEXTILES; TUFTING

PROBLEM TO BE SOLVED: To provide a sewing machine capable of switching between applying and release of tension to a needle thread more stably than the conventional one.SOLUTION: A sewing machine 1 includes: a presser bar 24; a vertical movement mechanism 20; a thread take-up lever 51; thread tension devices 110, 130; a switching mechanism; a first driving mechanism; and a second driving mechanism. The switching mechanism has: a first arm part capable of swinging to a first direction and a second direction; a first energization member for energizing the first arm part to the first direction; and a switching member capable of switching between applying and release of tension to a needle thread by the thread tension devices 110, 130 according to the swing position of the first arm part. The first driving mechanism is connected to the switching mechanism, and swings the first arm part from a normal position to the second direction by a predetermined amount at thread cutting time. The second driving mechanism swings the first arm part from the normal position to the second direction by an amount according to the vertical position of the presser bar 24 when the vertical movement mechanism 20 pushes up the presser bar 24 in a state where the first driving mechanism does not drive, and swings the first arm part to the first direction by the amount according to the vertical position of the presser bar 24 when the vertical movement mechanism 20 pushes down the presser bar 24. 【課題】上糸への張力付与、解除を従来に比べ安定して切り替え可能なミシンを提供すること。【解決手段】ミシン１は押え棒２４、上下動機構２０、天秤５１、糸調子器１１０、１３０、切替機構、第一駆動機構、第二駆動機構を備える。切替機構は第一方向及び第二方向に揺動可能な第一腕部、第一腕部を第一方向に付勢する第一付勢部材、第一腕部の揺動位置に応じて糸調子器１１０、１３０による上糸への張力付与と解除を切り替え可能な切替部材を有する。第一駆動機構は切替機構と接続し、糸切り時に第一腕部を通常位置から第二方向に所定量揺動する。第二駆動機構は第一駆動機構が駆動しない状態で上下動機構２０が押え棒２４を上げる時、押え棒２４の上下位置に応じた量第一腕部を通常位置から第二方向に揺動し、上下動機構２０が押え棒２４を下げる時、第一腕部を押え棒２４の上下位置に応じた量第一方向に揺動する。【選択図】図２