Mascot constant force spring is made by the rolled stainless steel ribbon, through a professional machine to stereotypia the high strength steel ribbion. When it is straightened by an external force, the constant force spring will roll by naturally and then generate elastic force. Thereby, the object can go back to the appoined origianl place. Comparing with the traditional line spring, the advantage of the constant force spring is: it keeps particular elastic force during the route, and route of the prestressing is short, that is say, we can get the necessary elastic force with a shorter route, the original length is smaller than the line spring, unlimited route.