Devices generating synchronizing signals in sewing machines

In a sewing machine having a needle bar means capable of transverse oscillation thereof relative to the direction of fabric feed in said sewing machine, feed means for adjusting the length and direction of said fabric feed, first actuator means for adjusting the transverse position of said needle bar means in response to control signals provided thereto, second actuator means for adjusting the positional displacement of said feed means in response to control signals provided thereto, rotatable main shaft means operatively connected to said needle bar means for enabling said transverse oscillation thereof, and main drive motor means drivingly connected to said main shaft means and said feed means for enabling sewing by said sewing machine;

• the improvement comprising means for generating a stop control synchronizing signal to said main drive motor means, said generating means comprising a first magnetic sensor means associated with said main drive motor means for providing said stop control synchronizing signal thereto, and a first magnet means disposed for synchronous rotation with said main shaft means for interacting with said first magnetic sensor means for a sufficient angular interval of rotation to enable stopping of said main shaft means in a predetermined arc of rotation of said main shaft means, said first magnet means comprising a pair of magnets angularly spaced apart from each other in the direction of rotation of said main shaft means by substantially said predetermined arc of rotation.

In a sewing machine having a needle bar means capable of transverse oscillation thereof relative to the direction of fabric feed in said sewing machine, feed means for adjusting the length and direction of said fabric feed, first actuator means for adjusting the transverse position of said needle bar means in response to control signals provided thereto, second actuator means for adjusting the positional displacement of said feed means in response to control signals provided thereto, rotatable main shaft means operatively connected to said needle bar means for enabling said transverse oscillation thereof, and main drive motor means drivingly connected to said main shaft means and said feed means for enabling sewing by said sewing machine;

• the improvement comprising means for generating a stop control synchronizing signal to said main drive motor means, said generating means comprising a first magnetic sensor means associated with said main drive motor means for providing said stop control synchronizing signal thereto, and a first magnet means disposed for synchronous rotation with said main shaft means for interacting with said first magnetic sensor means for a sufficient angular interval of rotation to enable stopping of said main shaft means in a predetermined arc of rotation of said main shaft means, wherein said generating means further comprises a soft iron loop substantially surrounding the area of interaction of said first magnet means and said first magnetic sensor means for facilitating closure of the magnetic path formed in said area and increasing the associated flux density within said area.