Abstract: An umbrella cover for a wind-stable umbrella is provided. The umbrella cover includes a main cover provided at a central area with at least one opening and a compensating cover adapted to loosely close the at least one opening on the main cover for a wind passage to exist between the main and the compensating covers. The at least one opening is provided at an outer edge with flaps. Free ends of these flaps upward and radially outward extend, allowing the flaps to function like a one-way valve. When a wind blows into the umbrella and moves upward to pass the at least one opening of the main cover, the flaps can be flattened by the wind for the wind to pass the wind passage and move out of the umbrella, protecting the umbrella against an overstrong wind pressure. When a wet wind sideward blows against the umbrella, free ends of the flaps are blown open to block the wind passage, stopping wind and rain from invading the umbrella via the at least one opening.

Abstract: An intermediate rib for collapsible umbrella is provided. The collapsible umbrella includes multiple sets of rib arrangements each of which includes an intermediate rib and an intermediate tie in addition to many other ribs and ties. The intermediate rib and tie are associated with each other by a collar put around them. The intermediate rib includes an U-shaped inner part that is adapted to support and pivotally connect to other appropriate ribs, and a round outer part that is sufficiently flexible to elastically bend in response to a wind pressure without becoming broken. The outer part of the intermediate rib bends naturally under a tension of the cover of the umbrella when the latter is stretched, giving the stretched umbrella a smooth and graceful appearance.