Patent ID: 7620472
Filing Date: 2009-11-17
Classification: D05B

Abstract:
1. A sewing machine which is capable of executing a free-motion sewing while a feed dog is accommodated in a bed and a workpiece cloth to be sewn is manually moved by an operator, comprising: a sewing machine motor; a main shaft driven by the sewing machine motor; a needlebar having a lower end to which a sewing needle is attached; a needlebar driving mechanism that vertically drives the needlebar via the main shaft; a presser foot that presses the workpiece cloth; an imaging device that images at least an area of the workpiece cloth near to the sewing needle; a movement amount operating device that obtains by a movement amount of the workpiece cloth based on image data supplied from the imaging device; a setting device that sets a stitch pitch on the workpiece cloth; a comparing device that compares the movement amount of the workpiece cloth obtained by the movement amount operating device and the stitch pitch set by the setting device; a cloth movement limiter that limits a manual operation of the workpiece cloth, the manual operation applying an only external force to increase or decrease the movement amount; and a control device that controls the cloth movement limiter according to a result of comparison by the comparing device.