| 摘要 |
733,338.. Endless belt conveyers. LEWIS, J., and RUBBER IMPROVEMENT, Ltd. Feb. 12, 1953 [Nov. 12, 1951; Jan. 17, 1952; Feb. 13, 1952], Nos. 23841/51, 1381/52 and 3789/52. Class 78 (1). [Also in Group VIII] Laminated sheet materials suitable for conveyer belts are made by securing the component parts comprising a fabric interlayer or layers and thermoplastic covers, or two or more fabric interlayers with a thermoplastic layer between, with or without thermoplastic covers to form a handlable carcass-and then passing the assembly to a fusing machine. The parts may be secured by threads (e.g. by stitching), which may be of the same thermoplastic material, or by spot welding by direct or induction heating. The interlayer may be of textile or non-textile synthetic or natural material such as metal, plastics, cotton, glass or asbestos in the form of fibres, laminae or interlocking or other configuration. 'It may consist of twisted stranded or hollow wire which may be hardened, plated or processed and incorporated into a woven fabric of cotton, wool, nylon, or rayon or other textile material. The thermoplastic matrix material may be vinyl, vinylidene, vinyl-formal, vinyl-butyral, vinyl alcohol, ethylene, amide or sulphide polymer, or a thermoplastic chemical derivative of lignin or cellulose. It may be in sheet form or be spread as a thermoplastic dough on to the interlayer. The edges of the assembly may be exposed and covered by a separate fusing operation using thermoplastic dough, or by application of a calendered or extruded edge strip subsequently fused on to the material. As shown (Fig. 2), layers or plies of fabric 1 previously coated with thermoplastic material and fused are superimposed on a table 5. Heavy sewing machines operating at 7 sew the laminae into a handlable carcass, to which is applied the cover stock of thermoplastic material. The assembly is fused, cut to width, and channel section edging strips applied and fused into place. |
