| 摘要 |
An improved hydraulic crane comprising at least one lifting cylinder to pivot the crane arm in a vertical plane relative to the crane post. A pressure-fluid line associated with the cylinder is connected to a movement-damping accumulator. In addition, a non-return valve is inserted between the cylinder and the accumulator to allow flow of pressurized liquid in one direction only away from the cylinder. A drainage line is connected to the accumulator, said drainage line incorporating a pressure-limiting valve. Owing to this arrangement, any added loads that arise as a result of sudden, shock-like pressures may be absorbed upon pressure relief in the accumulator without imparting jerky return movements to the crane arms. |
