Pneumatic traction device with electrically controlled compressor and relief valve

A portable pneumatic traction device comprising:

• a pneumatic cylinder enclosing a pneumatic piston;
• a shaft having one end connected to the pneumatic piston;
• a carriage traction device connected to the shaft at the other end thereof;
• a surface mounting device for mounting an end of the pneumatic cylinder to a surface;
• a controllable air compressor for supplying compressed air to a pressure chamber formed within the pneumatic cylinder on a side of the pneumatic piston;
• a one-way valve connected between the air compressor and the pressure chamber for preventing airflow in the direction from the pressure chamber to the air compressor but allowing airflow from the air compressor to the pressure chamber;
• a controllable relief valve connected to the pressure chamber within the pneumatic cylinder for releasing air from the chamber upon opening the relief valve;
• electrical control means connected to both the controllable air compressor and the controllable relief valve whereupon when the air compressor is actuated, the pneumatic traction device applies a traction force to the carriage traction device and when the relief valve is opened, the traction force applied to the carriage traction device is relaxed.