| 摘要 |
In forming a backseam for a shoe upper two quarters are assembled on two surfaces of a forming member which meet at a curved edge corresponding to the shape of the backseam, and the edges of the quarters are bonded together, the edges of the quarters being arranged to abut at the edge of the forming member, or the edge of the first quarter being bent around the edge of the forming member on to the second surface and overlapped by the edge of the second quarter. Leather quarters are bonded by adhesive, but weldable plastic coated fabric quarters are bonded by welding. The forming member may have parallel surfaces with a rounded edge (Figs. 4, 5, Figs. not shown), one surface chamfered (Figs. 2, 3), or both surfaces chamfered (Figs. 6-9). Alternatively the member bay comprise curved, preferably cylindrical, surfaces 124, 126 (fig. 10) meeting at a curved edge 128 at approximately 90 degrees. The seam shown in Fig. 3 is formed by folding the first leather quarter 8 around the edge of member 12, sticking it thereto by pressure-sensitive adhesive, scouring the edge portion 22 until it is level with the second surface 20, coating with adhesive the skived face 6 of the second quarter and arranging it over surface 22, and bonding the parts together by heat and slight pressure using a dielectric heating apparatus. In Figs. 4 and 5 the quarters are of cloth coated with polyvinyl chloride and are arranged with the cloth innermost. The coating 46 of quarter 40 is skived at 52 and overlapped by the edge of quarter 32. Metal template 48 with the quarters is lightly pressed between bed 58 and block 60 of silicone rubber and a high frequency electric field established by electrode 64. In Figs. 6-9 quarters comprising layers of leather 76, 84, polystyrene impregnated fabric 78, 86, to form a counter stiffener, and lining leather 80, 88 are skived at 83, 96, and 112, the latter surface is coated with adhesive and covered by the skived surface 98 of layer 84 and the parts joined by high frequency heating. The seams shown in Figs. 11-18 are formed on former 122 (Fig. 10). The quarters comprise fabric 130, 132 coated with polyvinyl chloride (Figs. 11, 13, 14), polystyrene impregnated fabric (Fig. 12), leather (Figs. 15, 16), or layers of leather 191, heat mouldable stiffener 192, and lining 193 (Figs. 17, 18). The seams are formed by skiving one surface of the first quarter (Fig. 11) or on the surface of both quarters (Figs. 15, 16, 18), by skiving two surfaces of the first quarter which engage between two reentrant skived faces of the second quarter (Fig. 17), or by butting the quarters (Figs. 13, 14). The adhesive may be heat or solvent activated. A heel stiffening blank 140, 160 may be incorporated in the seam (Figs. 12, 14). |
