Rib assembly for multiple-fold umbrella having plastic intermediate rib interconnected among light ribs

A rib assembly for multiple-fold umbrella comprising:

• a top rib pivotally secured to an upper notch formed on a top portion of a central shaft;
• a stretcher rib pivotally connected between the top rib and a lower runner slidably held on said central shaft;
• an intermediate rib having a cross section of H shape and pivotally connected to said top rib;
• a connecting rib pivotally connected between said stretcher rib and said intermediate rib;
• an outer rib pivotally secured to said intermediate rib;
• and
• a spring rib made of light-weight materials including plastic and aluminum alloy and pivotally connected between said top rib and said outer rib, said spring rib slidably coupled with said intermediate rib by a ring member, with said ring member fastened on said intermediate rib for passing said spring rib through said ring member;
• each said top rib, said stretcher rib and said connecting rib made of aluminum alloy;
• the improvement which comprises:
• said intermediate rib made of materials capable for resisting deformation, bending and twisting, including plastic, engineering plastic, and reinforced plastic material, and composite reinforced with plastic material;
• said ring member firmly fastened on said intermediate rib for passing said spring rib within said ring member for slidably coupling said spring rib to said intermediate rib.