| 摘要 |
<p>1517914 Reinforcing cords; non-woven fabric DUNLOP Ltd 14 Aug 1975 [22 Aug 1974] 36889/74 Headings D1R and D1T [Also in Division B7] A reinforcement for a flexible article comprises at least one layer of parallel cord fabric of cords comprising at least two strands of wires, the direction of lay of the wires in each strand of a cord being the same as the direction of lay of each strand in the cord, and the cords having an elongation at break of not more than 5%. Preferably the cord strands are arranged such that the elongation of the cords at break is less than 4% and more preferably in the range 1 to 3%. The strands may each extend helically such that the cord is coreless or there may be one strand acting as a central core. If a core strand is present it should be surrounded by at least two outer strands wound such that each outer strand is adjacent both the core strand and at least one other outer strand. Adjacent strands may be either in direct contact with each other or separated by a film of rubber or other material. The strands may be twisted around each other or laid around each other with zero twist. Similarly the wires of each strand may be laid with or without twist. The wires forming each strand may be either cored or coreless but where one strand is to be used as a core strand it is preferable that said strand is coreless so as not to inhibit unduly the extensibility of the cord. The cords in the reinforcement layer may all have the same direction of lay. Where cords of opposite lay are present in a layer, successive adjacent cords may be of opposite lay to give a balanced construction. The cords may be provided with a helically extending wrapping wire to assist in improving handling. The use of Lang's lay cords for forming reinforcement has been found to reduce the energy consumption by the reinforcement during flexing as compared with a similar reinforcement comprising regular lay cords. When the fabric is embedded in a sheet of rubber and subject to flexing, the resulting hysterisis loop that is used to measure the energy loss set up during cyclical bending is less than that for corresponding test samples using similar reinforcement comprising regular lay cords. The cords may each be formed from three strands, each of ten brass-coated carbon steel wires of 0.18 mm diameter.</p> |
