Moving contact

A moving contact mounted on a vehicle having a roof for engaging to and transmitting electrical power from an electrical overhead line to the vehicle, the moving contact comprising:

• a support having a bottom;
• a sliding contact mounted to said support;
• a spring system configured as a sprung leg and having a restoring force and a reference point, said restoring force of said spring system is between 40N and 100N and is matched to a combined weight of said sliding contact and said support being less than 8 kg, said support mounted on said spring system, said sliding contact held in an electrically conductive connection to an overhead line by said restoring force of said spring system for transmission of electrical power from the overhead line to an electrically powered vehicle;
• a retaining apparatus having a height adjustable supporting arm, said spring system connected to said supporting arm;
• a drive mechanism connected to said supporting arm of said retaining apparatus for adjusting a height of said retaining apparatus and said sliding contact;
• a sensor for monitoring a distance between said reference point on said spring system and a contact point, said contact point located between said sliding contact and the overhead line, said sensor having two optical fibers and outputting a distance measurement signal, one of said two optical fibers being a transmitter and another of said two optical fibers being a receiver;
• a distance monitoring apparatus attached to said bottom of said support, said distance monitoring apparatus having a wedge-shaped shutter measurement strip disposed between said transmitter and said receiver of said sensor;
• a signal line;
• and
• an evaluation and control unit for receiving and evaluating said distance measurement signal received via said signal line connecting said evaluation and control unit to said sensor, said evaluation and control unit outputting a height adjustment signal to said drive mechanism for adjusting the height of said retaining apparatus if the monitored distance is outside a predetermined threshold interval for maintaining the electrically conductive connection between said sliding contact and the overhead line, the threshold interval having a length of 10 cm.