Hydraulic tensioning apparatus for tightening workpieces and the like, having a supply line connected to a pressure source

摘要

The hydraulic fastening, tensioning or tightening device has at least one supply line (30) connected to a pressure source. It also has an outflow line (32) preferably connected to an oil sump. A working line (24,26) can be hydraulically connected to a hydraulic load such as a piston and cylinder device (12). The device also includes a pressure regulating valve unit (34) with an input port and an output port and a remote control port. A control line (36) is connected to the remote control port. This provides a connection to a hydraulic section where a pressure can be given which is different from the pressure at the input and output ports. The hydraulic section can be arranged inside or outside the hydraulic tensioning device (10).Independent claims also cover a pressure regulating valve.