Abstract: An addition to additive manufacturing sews a number of printed substrate sheets together using industrial sewing machine technology. Portions of the final 3D object that will be solid are sewn together into bundles of the object with a needle protruding through the top of the bundle via a sewing machine with a looping mechanism connecting the thread loops under each bundle of printed substrate sheet layers. This will result in many well connected stack bundles that are then stacked in alignment to form the final stack. During heat and compression, the stitch thread may bunch together and become entangled with the cooled plastic of the final solid 3D object. Removal of the excess substrate may proceed as usual, since the sewing is applied only in the solid portions of the final object. The end result will be a part with much higher strength in the Z axis.

Abstract: The present invention provides a fabric tensioning device for stretching fabric on a sewing machine. The fabric tensioning device includes a cylindrical frame having a window extending in a longitudinal direction. A fabric clamping member clamps down the cloth material against the frame for presenting the material to the embroidery needle at the window in a tensioned state. The clamping member opens and closes on the frame and has a pair of opposing fabric clamps on the left and right side of the frame that are oblong in the longitudinal direction with open front edges. The fabric clamps are tightened against the frame by belts in the front and rear thereof.

Abstract: A sewing machine accessory with an accessory head which can be quickly and easily attached and removed from a sewing machine. One version of the accessory head can be mounted to a sewing machine foot, while another version can be mounted on a sewing machine shank. Either version can use a protrusion in a mating slot to serve as the mounting connection, configured so that simply inserting the protrusion into the slot is sufficient for attachment, and simply removing the protrusion from the slot is sufficient for detachment. A particular embodiment of the accessory can enable straight seams or hems to be sewn parallel to a material edge without requiring a steady hand or great skill by the operator. An edge guide is provided with a predetermined offset from the sewing machine needle, thus permitting the operator to guide the material through the sewing mechanism in a very straight line, with the resulting seam being a consistently accurate distance from the edge of the material.

Abstract: Method and apparatus for forming and joining large and small hems particularly on denim jeans and other types of trousers. An internally folded large hem is formed mechanically and in a highly accurate manner by engaging the end portion of a trouser leg under circumferential tension and folding a projected hem margin into the trouser leg while supporting opposite sides of the trouser leg in a region immediately adjacent to the desired hem fold line. A full depth small hem may be formed by compressing a limited portion of the large hem into a fold, with the raw edge of the fabric positioned substantially at the fold line of the large hem. The configuration of the compressed limited portion is retained until the sewing machine is in position to grip it and commence sewing. A continuous fold former is brought into position before sewing is commenced to complete the small hem folding initiated by the initial compression.