Pantograph device of trolley truck

A pantograph device mounted on a trolley-type truck that is capable of traveling in either a trolley mode in which the truck travels on power obtained from an overhead wire or a non-trolley mode in which the truck travels without obtaining power from an overhead wire, the pantograph device comprising:

• a base frame;
• a bottom frame rotatably attached to the base frame;
• a top frame rotatably attached to a top end portion of the bottom frame through a connecting shaft;
• a collector shoe rotatably supported by a top end portion of the top frame;
• an actuator for erecting and lowering the bottom frame and that is attached to the base frame;
• said top frame having an arm portion extending opposite to the top end portion with the connecting shaft in between;
• and
• one or more tension springs, each respectively having a first end connected to the base frame and a second end connected to the base end portion of the top frame, and each of which causes the top frame to rotate upwardly with respect to the bottom frame about the connecting shaft,
• wherein a tensile force produced in the one or more springs is increased by erecting the bottom frame by the actuator and the top frame is rotated upward about the connecting shaft by the increased tensile force.