Upper thread guide mechanism for sewing machines

An upper thread guide mechanism for a sewing machine having a frame, a rotatable main shaft housed in the frame and adapted to be rotated therein, an upper thread supply source and a sewing needle, said upper thread guide mechanism providing a path for an upper thread extending from the upper thread source to the sewing needle, comprising:

• a pair of spaced-apart thread guide means having a through passage for allowing said upper thread to pass therethrough and disposed with a predetermined space therebetween, and
• a thread take-up lever means, having a portion adapted to be reciprocated across said space between said pair of thread guide means such that during a forward motion of said take-up lever means a front end thereof arrests a portion of said upper thread disposed between said pair of thread guides and draws said upper thread while bending the same into a V-form and during a return motion said take-up lever releases said upper thread, wherein said reciprocating portion of said thread take-up lever means has a first side which is directed forward during a forward stroke and a second side which is directed forward during a return stroke, and said second side is shaped such that when the thread is engaged thereby during said return stroke of said thread take-up lever means said second side allows said upper thread to pass thereover as the thread take-up lever means is moved.

An upper thread guide mechanism for a sewing machine having a frame, a rotatable main shaft housed in the frame and adapted to be rotated therein, an upper thread supply source and a sewing needle, said upper thread guide mechanism providing a path for an upper thread extending from the upper thread source to the sewing needle, comprising:

• tension means for imparting tension to said upper thread;
• a thread take up spring adapted to engage said upper thread to absorb any slack thereof;
• thread take-up lever means for taking up said thread, having a portion adapted to be reciprocated by driving motion from said main shaft such that during a forward motion of said take-up lever means a front end thereto arrests a portion of said upper thread and draws said upper thread;
• and
• a pair of spaced-apart thread guide means having a through passage for allowing said upper thread to pass therethrough and across the reciprocating motion of said take-up lever means and disposed with a predetermined space for allowing said front end of said thread take-up lever means to be reciprocated therebetween, said tension means, said thread take-up spring, said thread take-up lever means and said thread guide means being supported inside said frame;
• and
• said frame being formed with a slit at a position corresponding to said through passage of said thread guide means.

An upper thread guide mechanism for a sewing machine having a frame, a rotatable main shaft housed in the frame and adapted to be rotated therein, an upper thread supply source and a sewing needle, said upper thread guide mechanism providing a path for an upper thread extending from the upper thread source to the sewing needle, comprising:

• tension means for imparting tension to said upper thread;
• a thread take up spring adapted to engage said upper thread to absorb any slack thereof;
• thread take-up lever means for taking up said thread, having a portion adapted to be reciprocated by driving motion from said main shaft such that during a forward motion of said take-up lever means a front end thereto arrests a portion of said upper thread and draws said upper thread;
• and
• a pair of spaced-apart thread guide means having a through passage for allowing said upper thread to pass therethrough and across the reciprocating motion of said take-up lever means and disposed with a predetermined space for allowing said front end of said thread take-up lever means to be reciprocated therebetween, said path for said upper thread having a portion extending substantially linearly;
• and
• said tension means, said thread take-up spring, said thread take-up lever means and said thread guide means being arranged along said linearly extending portion of said path for said upper thread in this sequence.