Abstract: In a device for forming ornamental stitch seams, which comprises two or more needles (3a, 3b) moving alternately backward and forward through a needle plate (2) and a looper (5) cyclically movable following an elliptical trajectory (t) under the needle plate (2), the needles (3a, 3b) describe inclined trajectories (y) to form, with the needle plate (2), an acute angle turned towards the sewing direction (A), for crossing the looper trajectory (t) at a "crossing area" that, relative to a vertical direction (v) passing by the point at which the needles (3a, 3b) get through the needle plate (2), is shifted in a direction opposite to the sewing direction (A).

Abstract: In a two-needle sewing machine for making an ornamental stitch without a cover stitch, at least one intermediate lug (17) is provided which is disposed in side by side relation with respect to an upper thread take-up (13) engaged to the needle bar (7), said intermediate lug, in the absence of a workpiece (4) on the needle plate (8), is brought to a work position in which it interferes with one of the needle threads (4a, 4b) coming from an auxiliary thread take-up (12) being part of a feed unit for the needle threads. In the presence of the intermediate lug (17) in the work position, the orientation of the needle thread (4a) intercepted by said intermediate lug is suitably deviated with respect to the upper thread take-up (13), so as to cause a tension release on the needle thread itself during the raising steps of the needles (3a, 3) towards the upper dead center of their reciprocating motion.

Abstract: In a trimming sewing machine of the type adapted to carry out a two-thread overedge stitch, provision is made for a hooked element (15) integrally associated with the upper looper (10), which hooked element has an end work portion (15a) disposed in parallel side by side relation with the end work portion (10b) of the upper looper. The hooked element (15) engages the sewing thread (3) carried by the needle (2) at the beginning of the downward stroke of the needle. Following the downward stroke of the upper looper (10), the hooked element (15) drags along the sewing thread (3) beyond the lateral edge (5a) of the workpiece (5). Thus paired finishing portions (17a, 17b) are formed along the sewing thread (3) and they extend from each of the insertion points of the needle (2) into the workpiece (5) as far as close to the lateral edge (5a) of the workpiece (5).