US Patent 9857020 Lifting structure with adjustable bearing capacity

A lifting structure with adjustable bearing capacity is provided. The lifting structure comprises a main body, a carrier, a main constant force spring, and at least one auxiliary constant force spring. The main body comprises at least one slide and at least one actuating module. The main constant force spring connects to the carrier. The actuating module is able to be selectively switched between a non-actuating position and an actuating position. When the carrier is driven from the top of the lifting structure along the slide, at least the main constant force spring provides a constant force to the carrier.