Umbrella structure having at least one mushroom-shaped hub for enabling rapid assembly of main rod and supporting members

An umbrella structure having at least one mushroom-shaped hub for enabling rapid assembly of a main rod and supporting members, comprising:

• at least one mushroom-shaped hub having a hollow tubular body, wherein each said mushroom-shaped hub has two ends respectively formed with a first opening and a second opening, the first and second openings of each said mushroom-shaped hub are in communication with each other, and each said mushroom-shaped hub has a cap portion which is adjacent to the first opening thereof, bulges in a radial direction of the tubular body thereof, and is formed with a plurality of evenly distributed grooves extending in a radial direction of the first opening thereof;
• a plurality of supporting members each having an end whose diameter is less than a diameter of the first opening of a corresponding said mushroom-shaped hub but is greater than a width of each said groove of the corresponding mushroom-shaped hub, such that the end of each said supporting member can pass through the first opening of a corresponding mushroom-shaped hub and be received in the cap portion of the corresponding mushroom-shaped hub while a remaining portion of the each said supporting member passes through a corresponding said groove of the corresponding mushroom-shaped hub and extends out of the cap portion of the corresponding mushroom-shaped hub;
• and
• a main rod extending through the first and second openings of each said mushroom-shaped hub such that not only the end of each said supporting member is limited in position in the cap portion of a corresponding said mushroom-shaped hub, but also a portion of each said supporting member that is adjacent to the end thereof is movable only in a corresponding said groove of a corresponding said mushroom-shaped hub.