Speed controller for controlling revolution speed of upper shaft of cycle sewing machine

A speed controller for controlling revolution speed of an upper shaft of a cycle sewing machine comprising:

• an upper shaft horizontally supported within the arm of a cycle sewing machine and serving as a main shaft of the cycle sewing machine;
• an operative portion fixed to the body of the cycle sewing machine and having a stop lever adjusting lever provided with a roller at an end portion thereof and a drive wheel adjusting plate at the upper portion thereof;
• a clutch portion comprising a ball receiver integrally formed by a ball receiver shaft and provided around the upper shaft, a ball positioned between the ball receiver and the drive wheel adjusting plate, a low speed drive wheel clutch plate fixed to the upper shaft movable relative to the ball receiver shaft, a high speed drive wheel clutch plate fixed to the upper shaft, a low speed drive wheel confronted with the low speed drive wheel plate, a high speed drive wheel confronted with the high speed drive wheel plate;
• a control part having a feed cam gear engaged with a cam drive gear to which a revolution of the upper shaft is delivered;
• and
• a stop lever adjusting cam coaxially fixed to the shaft of the feed cam gear;
• characterized in that the stop lever adjusting cam has a small diameter portion where the low speed drive wheel plate and the high speed drive wheel plate are disengaged from each other for giving a neutral position to the periphery thereof, middle diameter portions respectively continuous from the small diameter portion at a first end portion and a last end portion of the small diameter portion where the low speed drive wheel is engaged with the low speed wheel clutch plate, and a large diameter portion positioned between the middle portions opposite the small diameter portion where the high speed drive wheel is engaged with the high speed wheel clutch plate, and a displacement cam operative member attached to the large diameter portion of the stop lever adjusting cam at the first portion thereof by a fixing means which can be adjusted in the circumferential attaching position.