Super-shortened multiple-fold umbrella

Abstract

A multiple-fold umbrella includes a telescopic central shaft having seven tubes telescopically coupled with one another, with an outermost tube having no (or zero) concave portion formed on the outermost tube, and with an innermost tube having six concave portions circumferentially formed on the innermost tube, each concave portion recessed in the tube centripetally about a longitudinal axis of the shaft and defining a central angle of sixty degrees, and the tubes gradationally increasing the number of the concave portions from the outermost tube towards the innermost tube to define an air chamber between a concave portion of an inner tube and a circular periphery of an outer tube neighboring to the inner tube for a smooth slidable coupling of every two neighboring tubes.

Description

BACKGROUND OF THE INVENTION [0001] U.S. Pat. No. 6,035,873 (the prior art) invented by the same inventors of this application disclosed a multiple-fold umbrella having gradationally convex telescopic shaft which may be provided for penta-fold umbrella as shown in FIG. 16˜23 of the accompanying drawings of the prior art. [0002] However, this prior art still has the following drawbacks: [0003] 1. Reviewing the smallest (in diameter) uppermost tube (10), it has four concave quadrants (V), which are gradually increased (from 0V to 4V) from the outermost tube (14). If the umbrella is influentially made for hexa-fold (or six-fold), it is impossible to do so because a circle can be divided into four concave quadrants (4V) only. So, the prior art can be provided for making a penta-fold umbrella only. [0004] 2. The multiple-fold shaft (1) includes plural telescopic tubes tapered upwardly so that a large aperture will exist between the runner (23) and the uppermost tube (11 or 10), thereby ca...

AI Technical Summary

Benefits of technology

[0007] The object of the present invention is to provide a multiple-fold umbrella including a telescopic central shaft having seven tubes telescopically coupled with one another, with an outermost tube having no (or zero) concave portion formed on the outermost tube, and with an innermost tube having six concave portions circumferentially formed on the innermost tube, each concave portion recessed in the tube centripetally about a longitudinal axis of the shaft and defining a central angle of sixty degrees, and the tubes gradationally increasing the number of the concave portions from the outermost tube towards the innermost tube to define an air chamber between a concave portion of an inner tube and a circular periphery of an outer tube neighboring to the inner tube for a smooth slidable coupling of every two neighboring tubes.

Problems solved by technology

However, this prior art still has the following drawbacks: 1.

The multiple-fold shaft (1) includes plural telescopic tubes tapered upwardly so that a large aperture will exist between the runner (23) and the uppermost tube (11 or 10), thereby causing unstable engagement of the spring catch (15) with the runner (23) in view of FIG. 1 of the prior art, and possibly causing unexpected closing of the umbrella from its opening state.

Such a circular-rod rib (28) is heavy, being not suitable for making a light-weight multiple-fold umbrella in modern umbrella industry.

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