Abstract: The construction of an umbrella cover is provided wherein the periphery of the umbrella cover cloth is arranged to provide straight meshes. The umbrella cover construction can accommodate umbrella ribs which are arranged in either equal or unequal intervals therebetween. The construction of the cover cloth is arranged with the radially extending umbrella ribs disposed on the bias of the cloth and coupled to peripheral portions thereof, having straight edges extending therefrom which are substantially either parallel or orthogonal to the warp or weft of the cloth. Thus, the umbrella cover can be formed of a single piece of material, upon which a decorative pattern can easily be printed thereon, while still allowing the umbrella cover to be stretched, when the umbrella is opened, to form a curved surface.

Abstract: Expansible type triangular umbrella ribs and the related collapsing mechanism, wherein the expansible first main rib is arranged to penetrate through the second main rib which is connected with the linking rib, the rear end of the first main rib being directly connected with the front end of the first support rib by pivotal joint, the rear end of the linking rib being pivotally connected to the first support rib, such that the first main rib is expansible to slip along the pivotal connecton between the second main rib and the linking rib; the first main rib, the linking rib and the first support rib being to form a triangular rib structure, the front U-channel of the first support rib being to provide an prolonged flange for receiving the rear portion of the linking rib; the first main rib, the linking rib and the first support rib being arranged in a straight line at the time the umbrella being fully opened; at the time the pivotal connection of the first main rib and the first support rib being attached to