Bending cantilevered retractable umbrella

The innovative suggestion of this work is the usage of bended composite arms instead of complicated steel arms with hinges. The basic idea of the new structure is very simple, which is one of the best advantages of this structure. The bended arms could pre-stress the membrane surface and in the same time the membrane bends the arms, this interaction produces a harmonic structure with effective properties. The hinges can be avoided, because the open position of the umbrella created by the bend of the arms. Nowadays existing retractable funnel umbrellas are highly advanced, which is a result of decades of development, but the openingclosing process is quite complicated with very complex kinematics and complicated steel structure. Using the bended supporting elements a new structure for the retractable funnel umbrellas could be developed, which provides better structural behavior and simpler motion during the opening-closing process. The goal of this work is a development of a new type of convertible umbrella with innovative structure, which opens up new perspectives concerning the design of umbrella structures. The benefit of the new structure compared to the existing umbrella structures is a much easier working principle, which allows leaving the complex moving elements and joints. The main advantage of this structure comes from its simplicity as it simplifies the operation of umbrellas, making it a cost-effective and sustainable option.