A method for making a bow-shaped spring sofa and a bow-shaped spring sofa

A method for making a bow-shaped spring sofa, the bow-shaped spring sofa comprising a sofa seat cushion and a backrest, the sofa seat cushion internally comprising bow-shaped springs, a base frame or/and a seat cushion bottom board, the backrest internally comprising bow-shaped springs, a backrest frame or/and a backrest bottom board, the bow-shaped springs having a middle portion that is a raised arc and two ends that are respectively bent downwards to form bent surfaces, wherein the method for making the bow-shaped spring sofa comprising a method for making the sofa seat cushion and a method for making the backrest, the method for making the sofa seat cushion comprising the following steps:

• step 1:
• fabricating the base frame or/and the seat cushion bottom board;
• step 2:
• placing the bow-shaped springs longitudinally across the base frame or the seat cushion bottom board, securing the two ends of the bow-shaped springs to the base frame or the seat cushion bottom board, using a quadrangular steel wire frame to connect the bow-shaped springs with peripheral edges in one piece, and using a straight steel wire transversely placed in the middle to connect with each of the bow-shaped springs and the quadrangular steel wire frame to form a bow-shaped spring assembly;
• step 3:
• encasing the bow-shaped spring assembly by lining materials in a layered manner;
• wherein the lining materials include, from innermost to outermost, a lower covering layer, a filling material pad, an upper covering layer, and fiber filling, first sequentially covering the lower covering layer, the filling material pad, and the upper covering layer above the bow-shaped spring assembly, using needles and thread or connectors to partially connect and secure the lining materials to the bow-shaped spring assembly, thereby forming an initially shape-formed sofa seat cushion;
• step 4:
• lifting the edges of the upper covering layer, inserting straw bundles as shaping materials between the filling material pad and the upper covering layer in the regions corresponding to the front edge and the left and right sides of the upper part of the sofa seat cushion, then folding the upper covering layer downwards to enclose the straw bundles, and inserting a fixing needle through the lower covering layer, the filling material pad, the straw bundles, and the upper covering layer to fix the straw bundles initially;
• step 5:
• using a straw gathering needle to initially nudge and gather the straw bundles towards the front edge and the left and right edges of the upper part of the sofa seat cushion, then using a sewing needle and thread to stitch diagonally at a certain distance from the front edge and the left and right edges of the upper part of the sofa seat cushion, tying knots to sew the upper covering layer, the straw bundles, the filling material pad, and the lower covering layer together onto the bow-shaped spring assembly, forming a basic edge-tucking shape of the sofa seat cushion;
• step 6 :
• using an edge-tucking curved needle in conjunction with the straw gathering needle to shape the edges of the sofa seat cushion, using the edge-tucking curved needle and thread to stitch and tie knots along the front, left, and right edges of the upper part of the sofa seat cushion;
• using the straw gathering needle for nudging the straw bundles into a column shape, and enclosing and securing the straw bundles within the upper covering layer, completing an edge shaping of the sofa seat cushion;
• step 7:
• building upon the edge shaping of the sofa seat cushion completed in Step 6, fabricating a custom cover of the sofa seat cushion;
• the cover of the sofa seat cushion comprising a top face and three adjoining side faces, the inner side of a seam where the top face and the three side faces meet having a remaining edge, forming a piping on the outer side of the seam where the top face and the three side faces of the sofa seat cushion cover meet.