| 摘要 |
1. A filler cap for a tank for a hydrocarbon or like liquid, comprising a venting passage and a valve member (30, 40) in the shape of a disc which floats, in a chamber (22) inserted in the venting passage, between an inlet (26, 56) for exterior air and an outlet (34, 35) toward the tank, and which co-operates with a seat surrounding, inside said chamber, the air inlet so as to close said inlet under the action of the pressure of the liquid contained in the tank, characterized in that one of the confronting sides of the seat (28, 58, 46, 72) and valve member (30, 40, 50, 70) has a surface in the shape of a portion of a sphere (32, 42, 72) whereas the other of said confronting sides has a recess (28, 46, 74), so that the contact between said two sides occurs along a circular line surrounding the air inlet (26, 56) irrespective of the inclination of the valve member (30, 40, 50, 70), and in that the bottom (21) of the chamber (22) is provided with a plurality of peripheral orifices (34) communicating with the tank, the valve member (30, 40, 50, 70) having in confronting relation to said orifices (34) a continuous surface which is insufficient to cover all of said orifices simultaneously notwithstanding the fact that the diameter of the valve member is very large relative to the diameters of the orifices and the diameteral and axial clearance between the valve member and the chamber (22) is small. |
