Sewing machine fabric feed

摘要

To determine the action of feeding fabric through a sewing machine, a suitable point is registered on the fabric at intervals. The sum of the pulses as a result of successive sensor readings is compared with the data of the required stitch length and the gap between markings as a nominal pulse count. Where there is more than one fabric layer being stitched at the same time, each layer is marked for the sensors to register, and the pulse count for one layer is compared with the pulse count for the other layer to establish whether there is any undesired relative movement between the fabrics which has to be corrected.