Telescopic damper for pantograph - with gas cushion to provide rapid raising towards wire

摘要

The pantograph is fitted with a hydraulic damper to smooth out the pantograph vibrations on the wire and to extend the pantograph onto the wire with a set pressure. In order to speed up the time delay in reapplying the pantograph onto the wire after it has been depressed, such as when travelling under bridges, a pressurised gas pocket is included in the damper. This is separated from the fluid by a floating piston. The damper has assymetric cushioning characteristics and reduces the arcing between the wire and the pantograph. As an alternative to a floating piston, a flexible membrane can separate the fluid and the gas pocket.