Hydraulic cranes
US4317524A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1980 |
| Grant date | Mar 2, 1982 |
| Priority date | — |
| Expiry date | Mar 10, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66C13/18
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.