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1847年Ross Winans获得一项专利,用于铁路运煤的车皮,其特征是车皮的外形上部为圆型、下部为漏斗形。随后,Danmead
In 1847, Ross Winans won a patent for the carriage of coal for railroad cars, which is characterized by a rounded upper part of the wagon and a funnel-shaped lower part. Then, Danmead