| 摘要 |
960,853. Moulding railway sleepers. ETERNIT S.p.A. Oct. 13, 1961 [Nov. 2, 1960], No. 36776/61. Heading B5A. [Also in Division E1] Railway sleepers are formed by pressing laminated wet sheets of cement-asbestos in a mould to a maximum pressure below 300 kg/sq. cm., the maximum pressure being reached in less than five minutes. The sleeper is first formed from sheets of cement-asbestos between temporary walls on a tray containing the sleeper fittings, strengthening irons being introduced between the sheets. Walls comprising staves 3 with outlet ports 4 are then substituted so that during the subsequent pressing operation the excess water may escape into channels 5. By varying the width of the outlets 4, the maximum pressure, and the pressing time, the optimum amount of water for a satisfactory setting may be retained within the cement. |
