Lock stitch sewing machine piping cutter - with reciprocable knife blade mounted in guide block pivoting towards needle under control of pneumatic sensor

摘要

Sewing machine cutter is provided with a knife blade automatically reciprocable in a guide towards and away from a slot passed by the piping to be cut and a sensor controlling the cutting operation of the knife blade. Sensor is disposed at the same distance from the centre of the needle as the cutting location of the blade to induce the cutting cycle at the end of sewing on the piping. The cutter is used with a lock stitch sewing machine used for sewing on plastics piping or trimming to suitcases. Provision and disposition of the sensor permits accurate cutting of the piping without unnecessary overlap and without interruption of the sewing process.