FUELTANK CAP

PROBLEM TO BE SOLVED: To simplify the structure and assembling of a fuel tank cap, by constituting the structure so as to open or close a breathing passage only by selectively fitting a V-shaped projection provided at a manipulating knob and V-shaped notches having two kinds of depth provided at the cap body and by turning the knob. SOLUTION: When a cap is fitted to a fuel tank, the female screw 51a of the cap body 51 is screwed in the male screw equipped at the feed opening of the fuel tank and fastened thereto. When a manipulation knob 53 is turned, the front ends of two V-shaped projections 53d slide on the upper face of a circular rail 51c while getting into contact with the upper face and fit in the deep V-shaped notch and the shallow V-shaped notch provided in the circulation rail 51c respectively and stop therein. When the knob is turned further, The V-shaped projection 53d is raised against the elastic force of a spring 54 and transferred to the next V-shaped notch. When the V-shaped projection 53d is fitted in the deep V-shaped notch, the lower face of the head of the manipulation knob 53 is positioned to contact a packing and brought to a stop and the passage between the inside of the tank and the outside air is closed.