Dual-crown umbrella

Abstract

A dual-crown umbrella includes a first central post, an outer crown, a second central post, an inner crown, a third central post, a retainer, a plurality of ribs, a plurality of first stretchers, a plurality of second stretchers, and a covering fabric. The outer crown is fixed to an upper end of the first central post. The inner crown is fixed to an upper end of the second central post. The retainer is fixed to an upper end of the third central post. The first central post is telescopically movable within an upper end opening of the second central post. The second central post is telescopically movable in an upper end of the third central post. Each rib has an upper end pivoted to the outer crown. Each first stretcher has an end pivoted to the retainer and an opposite end pivoted to a first joint of the respective rib. Each second stretcher has an end pivoted to the inner crown and an opposite end pivoted to a second joint of the respective rib. The ribs support the covering. Thus, a dual-crown umbrella featuring excellent stability of support and effort saved opening operation is realized.

1 . An umbrella, comprising:
 a first central post;   an outer crown, which is fixed to an upper end of the first central post;   a second central post, which is tubular and has an inside diameter greater than an outside diameter of the first central post for telescopically receiving the first central post therein through an upper end opening so that the first central post is telescopically movable within an upper end portion of the second central post;   an inner crown, which is fixed to an upper end of the second central post;   a third central post, which is tubular and has an inside diameter greater than an outside diameter of the second central post for telescopically receiving the second central post therein through an upper end opening so that the second central post is telescopically movable within an upper end portion of the third central post;   a retainer fixedly disposed at an upper end of the third central post;   a plurality of ribs, each of which has an upper end pivoted to the outer crown, each rib forming a first joint and a second joint;   a plurality of first stretchers, each of which has an end pivoted to the retainer and an opposite end pivoted to the first joint of the respective rib;   a plurality of second stretchers, each of which has an end pivoted to the inner crown and an opposite end pivoted to the second joint of the respective rib, so that each second stretcher and the respective first stretcher form a crossing configuration of umbrella skeleton arrangement; and   a covering, which is supported by the plurality of ribs and is driven by the ribs to open/close the umbrella;   wherein to open the umbrella, the inner crown and the second central post are displaced longitudinally towards the retainer so as to expand the ribs to open the covering, and to close the umbrella, the inner crown and the second central post are displaced longitudinally away from the retainer so as to collapse the ribs inward to close the covering.   
     
     
         2 . The umbrella as claimed in  claim 1 , wherein the second central post comprises a device for controlling longitudinal movement of the inner crown and the second central post, the device comprising a collar slidably fit over an outer circumference of the third central post for opening or closing the umbrella, two link bars being mounted to opposite side portions of the collar in such a way that upper ends of the link bars respectively extend through through-holes defined in the retainer to connect to the inner crown, wherein longitudinal displacement of the collar drives the inner crown and the second central post through the two link bars to close or open the umbrella.