A strength member sewing machine is provided which comprises upper and lower feeder spools, a collection spool and idlers positioned on a support structure. A cord supply, a fabric shaper, a speed control and a pressure foot lift are positioned on the structure. Fabric from the spools is kept in tension with the idlers while moving toward the fabric shaper. The fabric from the upper spool is crimped while the fabric from the lower spool remains flat underneath the shaper. Between the fabric layers, pull cords are pulled through from the cord supply thru the fabric shaper. The fabric with crimps and with the pull cords inside the crimps is sewn to the fabric from the lower spool to create casings with a pull cord in the internal space of each casing. The joined fabrics with the pull cords are collected by the collection spool as a finished product.

A sewing machine includes a material sandwiching unit to sandwich two materials having annular edges from above and below while they are stacked so that the material on an inner wheel side is located on the lower side and the material on an outer wheel side is located on the upper side, wherein a part of the material sandwiching unit located above the two materials is vertically movable, the material sandwiching unit includes a curl-removing mechanism to straighten curls occurring on the edges of the two materials, the material sandwiching unit includes inclined parts that serve as the curl-removing mechanism and have edges extending backward from a farther side of the edges toward the edge side at a position where the two materials pass therethrough, and the inclined parts have air ejectors to eject air so as to form airflows that straighten portions of the materials where curls have occurred.

A sewing machine includes a material sandwiching unit to sandwich two materials having annular edges from above and below while they are stacked so that the material on an inner wheel side is located on the lower side and the material on an outer wheel side is located on the upper side, wherein a part of the material sandwiching unit located above the two materials is vertically movable, the material sandwiching unit includes a curl-removing mechanism to straighten curls occurring on the edges of the two materials, the material sandwiching unit includes inclined parts that serve as the curl-removing mechanism and have edges extending backward from a farther side of the edges toward the edge side at a position where the two materials pass therethrough, and the inclined parts have air ejectors to eject air so as to form airflows that straighten portions of the materials where curls have occurred.