控制单元设有预设的举升高度，左柱上安装有自动挡块。
Control unit with preset lifting height and automatic stop fitted at the left pillar.
提出了肋柱、肋梁和挡土板的计算单元划分以及计算模型的确定方法。
The calculating elements and the calculating model of rib-column, rib-beam and retaining plate of the supporting structure are proposed in this paper.
它通常包括以下十二类零件：螺栓、螺柱、螺钉、螺母、自攻螺钉、木螺钉、垫圈、挡圈、销、组合件和连接副、焊钉等。
Usually there are 12 categories which are bolt , stud, screw, nut , self tapping screw, wood screw, gasket, retainer ring, pin, composite member, bolting, and soldering lamp.
主营产品：各种紧固件、标准件、螺栓、螺柱、螺丝、螺钉、木螺钉、自攻螺钉、车削螺丝、组合螺丝、螺母、连接件、平垫、挡圈等。
Main products: various kinds of fasteners, standard, bolts, screws, bolts, screws, wood screws, tapping screws, turning the screw, the combination of screws, nuts, fittings, flat mat, ring, etc.
主营产品：各种紧固件、标准件、螺栓、螺柱、螺丝、螺钉、木螺钉、自攻螺钉、车削螺丝、组合螺丝、螺母、连接件、平垫、挡圈等。
Main products: various kinds of fasteners, standard, bolts, screws, bolts, screws, wood screws, tapping screws, turning the screw, the combination of screws, nuts, fittings, flat mat, ring, etc.
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