| 摘要 |
PROBLEM TO BE SOLVED: To provide a two-step telescopic cylinder device which is downsized, and improved in the ease-of-use and the range of uses. SOLUTION: A two-step telescopic cylinder 5 includes: a piston rod 11, and an inner cylinder tube 12; an outer cylinder tube 13; an inner extension oil-chamber 17; an outer extension oil-chamber 18, and an inner retraction oil-chamber 19; and an outer retraction oil-chamber 20. The inner extension oil-chamber and the outer extension oil-chamber are provided so as not to communicate with each other, and the inner retraction oil-chamber and the outer retraction oil-chamber are provided so as to communicate with each other. In the piston rod, a first oil path 25 communicating with the inner extension oil-chamber, a second oil path 26 communicating with the outer extension oil-chamber and a third oil path 27 communicating with the inner retraction oil-chamber are provided so as not to communicate with each other. A communication pipe-line 28 is provided in the bottom of the inner cylinder tube. One end of the communication pipe-line is inserted into the second oil path. When the piston rod and the inner cylinder tube relatively make telescopic operations, the length of insertion into the second oil path of the communication pipe-line is changed in accordance with the operation. COPYRIGHT: (C)2009,JPO&INPIT |
