Lower thread winding device

A lower thread winding device comprising:

• a bobbin including upper and lower flanges provided on a central shaft upon which a lower thread is to be wound and both ends thereof, the upper flange having a slit opened to an outer peripheral edge;
• a horizontal holder having an inner holder capable of accommodating the bobbin and an outer holder provided with a blade tip for catching a thread;
• a bobbin driving member provided on an axial center of the outer holder and capable of being rotated integrally with the outer holder;
• first moving means for moving the bobbin driving member to a connecting position in which the bobbin driving member and the bobbin are connected to cause the bobbin to be rotatable during an operation for winding the thread upon the bobbin and a separating position in which the bobbin driving member is disconnected from the bobbin during a sewing operation;
• a thread holding member including a thread engaging portion capable of holding a thread end of an upper thread supplied to a needle during the thread winding operation and a thread position regulating portion for positioning the upper thread on a supply side by the thread engaging portion during the thread winding operation to abut on the upper flange, the thread engaging portion being movable to a retreat position in the vicinity of an outer peripheral surface of the outer holder and an entry position in which the supplied thread is caused to enter an inner upper part of the inner holder to be positioned above the upper flange during the thread winding operation;
• second moving means for moving the thread engaging portion of the thread holding member to the retreat position and the entry position;
• an upper shaft clutch mechanism provided between a drive shaft to be driven by a sewing machine motor and a reciprocating member for reciprocating a needle bar and a thread talk-up in a vertical direction and capable of carrying out electrical switching into a connecting state in which the drive shaft is connected to the reciprocating member during the sewing operation and a holding state in which the connection is released and the thread take-up and the needle bar can be held in an upper position during a lower thread winding operation;
• and
• thread winding operation control means for bringing the upper shaft clutch mechanism into the connecting state to drive a sewing machine, thereby catching the upper thread connected to the needle by means of the blade tip of the outer holder and separately rotating the upper thread in upper and lower parts of the inner holder, then causing the thread engaging portion of the thread holding member to catch the upper thread passing over the inner holder, and thereafter operating the first moving means and the second moving means to cause the supplied thread connected between the thread engaging portion and the thread position regulating portion to enter the slit and bringing the upper shaft clutch mechanism into a release state so that the thread can be wound upon the bobbin without vertically moving the thread take-up and the needle bar during the thread winding operation.

A lower thread winding device comprising:

• a bobbin including upper and lower flanges provided on a central shaft upon which a lower thread is to be wound and both ends thereof, the upper flange having a slit opened to an outer peripheral edge;
• a horizontal holder having an inner holder capable of accommodating the bobbin and an outer holder provided with a blade tip for catching a thread;
• a bobbin driving member provided on an axial center of the outer holder and capable of being rotated integrally with the outer holder;
• first moving means for moving the bobbin driving member to a connecting position in which the bobbin driving member and the bobbin are connected to cause the bobbin to be rotatable during an operation for winding the thread upon the bobbin and a separating position in which the bobbin driving member is disconnected from the bobbin during a sewing operation;
• a thread catching and holding member including a thread holding portion provided in a tip portion and serving to hold a thread supplied during the thread winding operation and a thread engaging portion for engaging an upper thread, and a thread position regulating portion provided on a rear end side from the thread holding portion and the thread engaging portion and serving to position a supplied thread on a supply side by the thread holding portion and the thread engaging portion or the upper thread supplied as a lower thread during the thread winding operation to abut on the upper flange of the bobbin, in which a tip portion is always placed in a retreat position in the vicinity of an outer peripheral surface of the outer holder and is placed in an entry position in which the tip portion enters an inner upper part of the inner holder during the thread winding operation;
• second moving means for moving the thread holding portion and the thread engaging portion in the thread catching and holding member to freely advance or retreat between two positions including the retreat position and the entry position;
• an upper shaft clutch mechanism capable of carrying out electrical switching into a connecting state in which a drive shaft to be driven by a sewing machine motor is connected to a reciprocating member for reciprocating a needle bar and a thread take-up in a vertical direction during the sewing operation and a holding state in which the connection is released and the thread take-up and the needle bar can be held in an upper position during a lower thread winding operation;
• a first thread winding operation control portion for operating the first moving means and the second moving means to cause the supplied thread connected between the thread holding portion and the thread position regulating portion to enter the slit and for bringing the upper shaft clutch mechanism into a release state so that the thread can be wound upon the bobbin without vertically moving the thread take-up and the needle bar during the thread winding operation;
• and
• a second thread winding operation control portion for bringing the upper shaft clutch mechanism into the connecting state to drive a sewing machine during the thread winding operation, thereby catching the upper thread connected to a needle by means of the blade tip of the outer holder and separately rotating the upper thread in upper and lower parts of the inner holder, then causing the thread engaging portion and the thread position regulating portion in the thread catching and holding member to catch the upper thread passing over the inner holder, and thereafter operating the first moving means and the second moving means to cause the supplied thread connected between the thread holding portion and the thread position regulating portion to enter the slit and bringing the upper shaft clutch mechanism into a release state so that the thread can be wound upon the bobbin without vertically moving the thread take-up and the needle bar during the thread winding operation.