公开(公告)号：US5657834A

公开(公告)日：1997-08-19

申请号：US515465

申请日：1995-08-15

申请人： Randall D. Plaugher ,  James L. Hoying ,  John R. Harman

发明人： Randall D. Plaugher ,  James L. Hoying ,  John R. Harman

IPC分类号： B66F9/08 ,  B66F9/06

CPC分类号： B66F9/08

摘要： A lift truck provided with a fixed mast section, several moveable mast sections and a carriage supporting load carrying forks and operator's platform is hydraulically raised and lowered. Mast chains interconnect the fixed mast section and the moveable mast sections and the moveable mast sections and the carriage. One pair of cushioning devices is placed between the fixed mast section and lower most moveable mast section and a second pair of cushioning devices is placed between the uppermost moveable mast section and the carriage. Each cushioning device two spring elements, one with a relatively soft spring rate, the other with a relatively stiff spring rate. The cushioning devices and a common hydraulic connection between hydraulic cylinders combine to reduce the shock and jerk felt by the operator during mast staging while raising or lowering the mast in either an empty or loaded condition.

摘要翻译： 一个提供固定桅杆部分的升降车，几个可移动的桅杆部分和一个支撑载货叉和操作者平台的滑架液压升降。 桅杆链将固定的桅杆部分和可移动的桅杆部分以及可移动的桅杆部分和滑架相互连接。 一对缓冲装置放置在固定桅杆部分和最下部最可移动桅杆部分之间，并且第二对缓冲装置被放置在最高可移动桅杆部分和滑架之间。 每个缓冲装置有两个弹簧元件，一个具有相对较软弹簧的弹簧，另一个具有相对较硬的弹簧刚度。 缓冲装置和液压缸之间的公共液压连接结合在一起，以减少在桅杆分段期间操作者的冲击和冲击感，同时在空载或负载状态下升高或降低桅杆。