| 摘要 |
The present invention relates to a device for a hydraulically operated crane (10) of the type which comprises a crane arm (12), which is rotatable around a horizontal axis of rotation by means of a hydraulic lifting cylinder (24), an arm (20), henceforth termed a telescopic arm, arranged displaceably on the crane arm (12) and at least one hydraulic cylinder (30) fitted between the telescopic arm (20) and the crane arm (12) capable of displacing the telescopic arm mainly in parallel with the crane arm to change the radial range of the crane. The invention is characterised in that the piston in said hydraulic cylinder is disposed to compress an enclosed gas volume when the telescopic arm is pushed out. |
