| 摘要 |
In a plastic filler neck cap including therein a receptacle for a pressure control valve and a receptacle for an anti-leakage assembly, a positive-negative pressure valve is compactly constructed in such a manner that the valve body retainer plate is formed into a hat-like configuration including an upper portion with a passing hole at its center, an outer peripheral wall and a spring reception tongue; the valve body is in engagement with the valve body retainer plate whose passing hole sustains a portion of the valve body; the valve body presents a double-disk shape with a smaller upper disk and a larger lower disk having on the upside a peripheral upper ridge and on the downside a lower ridge inside the upper ridge, and further a center communication opening extending through both the disks; the diameter of the negative pressure valve body is predetermined larger than the extension of the lower ridge on the bottom of the valve body, forming a pan-like shape setting the opening side down with a skirt portion extending downwardly at the periphery; and the negative valve body is accommodated in a valve body reception circular casing extending upwardly from the separation plate of the inner cap, while being compressed at the upper face thereof against the lower ridge of the valve body by means of an inner coil spring. |
