| 摘要 |
A roller press has a press roll and at least one pressure roll applying pressure to it. In the end region of each pressure roll, there is an associated positioning cylinder. The positioning cylinders relieve the pressure of the pressure roll against the press roll automatically upon an impermissible increase in the operating pressure in the positioning cylinder. For this purpose, each positioning cylinder has a safety valve which is operated either by the working fluid in the positioning cylinder to the pressure relief condition or by an electrical signal, in different embodiments, to relieve pressure in the positioning cylinder. The safety valves are coupled to each other by a signal line. When one safety valve relieves one positioning cylinder, all of the positioning cylinders are relieved. Details of the working fluid operated safety valves and of the electrically operated safety valves are disclosed, including details of the valve body and the application of pressures upon the valve bodies which causes them to shift. |
