Apparatus for adjusting timing of needle and looptaker of sewing machine
AssigneeAisin Seiki Kabushiki Kaisha
InventorsHitoshi Ishikawa, Tatsunori Fukuda
Life of this patent
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Abstract
An apparatus for adjusting a timing of a needle and a looptaker of a sewing machine provided at a zigzag sewing machine having an upper shaft for driving a needle bar, a lower shaft for driving a looptaker, a machine frame, and a timing belt for connecting and synchronizing the shafts includes a cam member including a first cam surface and a second cam surface, a first arm member and a second arm member supported by the machine frame and a first pulley and a second pulley mounted to the first arm member and the second arm member respectively and always contacting the timing belt, the first pulley following the first cam surface and the second pulley following the second cam surface.
Claims20
An apparatus for adjusting a timing of a needle and a looptaker of a sewing machine provided at a zigzag sewing machine having an upper shaft for driving a needle bar holding a needle, a lower shaft for driving a looptaker, a machine frame for rotatably supporting the upper shaft and the lower shaft, a timing belt for connecting and synchronizing the upper shaft and the lower shaft, the apparatus for adjusting the timing of the needle and the looptaker of the sewing machine comprising;
- a cam member including a first cam surface and a second cam surface and rotated by a driving force;
- a first arm member and a second arm member each rotatably supported by the machine frame;
- and
- a first pulley and a second pulley mounted to the first arm member and the second arm member respectively and always contacting the timing belt, the first pulley following the first cam surface and the second pulley following the second cam surface.
A zigzag sewing machine, comprising:
- an upper shaft for driving a needle bar holding a needle;
- a lower shaft for driving a looptaker;
- a machine frame for rotatably supporting the upper shaft and the lower shaft;
- a timing belt for connecting and synchronizing the upper shaft and the lower shaft;
- and
- an apparatus for adjusting a timing of the needle and the looptaker of the sewing machine, the apparatus including;
- a cam member including a first cam surface and a second cam surface and rotated by a driving force,
- a first arm member and a second arm member each rotatably supported by the machine frame;
- and
- a first pulley and a second pulley mounted to the first arm member and the second arm member respectively and always contacting the timing belt, the first pulley following the first cam surface and the second pulley following the second cam surface.
In a zigzag sewing machine wherein upper and lower shafts are connected by a timing belt for concurrent rotations, a looptaker is rotated about a fixed axis in response to the rotation of the lower shaft, a needle is moved vertically in response to the rotation of the upper shaft, and the needle is shifted laterally between first and second stitch positions with respect to the looptaker, the improvement for establishing the needle's equally optimal timed relationship with the looptaker at each of the first and second stitch positions comprising;
- a cam member including a first cam surface and a second cam surface and rotated by a stepping motor;
- a first arm member and a second arm member each rotatably supported by the machine frame;
- and
- a first pulley and a second pulley mounted to the first arm member and the second arm member respectively and always contacting the timing belt, the first pulley following the first cam surface and the second cam pulley following the second cam surface.
Dependencies are inferred from the claim text.