Control of fabric feed mechanism on sewing machine includes programmed motorized actuation of feed control shaft

摘要

The feed control arrangements comprise a motor (180) connected to the control shaft of the feed dog drive mechanism, an interface (100) for the operator input for fabric feed distance and direction, calculation of motor rotation required to produce these feed steps (200), and corresponding control (300) of the motor (180). Control can be linked to a transverse movement of the needle to produce e.g. a zigzag, L-shaped or star-shaped stitch pattern. An independent claim is also included for the process of controlling the fabric feed by inputting (100) the planned stitch pattern by an operator, automatic determination of the corresponding size and direction of feed steps (200) and driving (300) a control motor (180) accordingly. The arrangement can include a sensor to provide feedback of motor rotation, setting of incremental and reverse feed steps and a display for showing the feed pattern. The control uses the deviation of the motor position from a reference position to determine the next step.