| 摘要 |
An automatic umbrella includes: a telescopic central shaft having a lower tube, an intermediate tube, an upper tube and a top tube telescopically engageable with one another; a rib assembly having at least a top rib pivotally secured to a middle runner slidably held on the central shaft, a top linking rib pivotally secured between the top rib and an upper notch fixed on the top tube, and a stretcher rib pivotally secured between the top rib and a lower runner slidably held on the central shaft, the top rib longitudinally formed with an elongate slot in the top rib and the upper, tube having a limiting pin fixed on the upper tube, at least an inner tension spring resiliently retained in the central shaft and urging the limiting pin upwardly, and an outer tension spring resiliently retained between the upper notch and a ring extension formed on the upper tube, whereby upon opening of the umbrella, the limiting pin one the upper tube is linearly guided in the elongate slot in the top tube for preventing twisting of the tubes of the central shaft and the rib assembly for a stable opening of the umbrella.
|
