Self-adjusting presser foot for assembler sewing machines

A self-adjusting presser foot in combination with a sewing machine, comprising:

• a small bearing frame (2) fixedly fastened to a presser bar (3) of the sewing machine;
• a shoe (4) engaged at a lower part of the small bearing frame (2), said shoe having a longitudinal opening (29) for receiving and guiding two opposite edges of two fabric pieces disposed in mutual side by side relation, said shoe having has a transverse slit (49) for accessing sewing means;
• cutting means (31) positioned upstream of the transverse slit (49) and close to said longitudinal opening (29) for trimming the side by side fabric piece edges;
• and
• said shoe having guide means (46) positioned at one end of said longitudinal opening (29) and acting downstream of the cutting means (31) and upstream of the transverse slit (49) for overlapping the trimmed fabric piece edges, wherein said shoe (4) comprises:
• a pair of front portions (5a, 5b) disposed parallel is side by side relation and defining said longitudinal slit (29);
• a pair of rear portions (6a, 6b) each disposed in alignment with one of said front portions (5a, 5b);
• a pair of side rocker arms (7a, 7b) each of which oscillably engages, according to horizontal axes transverse to the sewing direction, one of said front portions (5a, 5b) and one of said rear portions (6a, 6b) in respective alignment;
• a pair of interconnecting elements (10a, 10b) oscillatably engaged to the small bearing frame (2) and each carrying a fulcrum pin (14a, 14b) for one of said side rocker arms (7a, 7b), the axes of oscillation of said side rocker arms (7a, 7b) being oriented horizontally in a direction perpendicular to the sewing direction;
• a center rocker arm (15) oscillatably engaged to the small bearing frame (2) according to a horizontal axis parallel to a sewing direction and said rocker arms having opposite ends (15a, 15b) operatively connected to the interconnecting elements (10a, 10b) in order to balance the fulcrum pins (14a, 14b) of the side rocker arms (7a, 7b).