| 摘要 |
Improved check valve adapted for operation under light pressure, as in the oral inflation of inflatable articles. The valve has a valve body and a movable valve element therein, the valve element having a body which carries an annular sealing means cooperating with and selectively sealing an axially outwardly converging valve seat on the valve body, the angle of engagement between the sealing member of the valve element and the valve seat at the valve-closed position of the valve element exceeding the angle of repose of the engaging parts of the sealing member and the valve seat. The sealing member, which is molded in place on the body of the valve element, has an annular main part surrounding an enlarged head on the body of the valve element and a sheet-like disc which is integral with the main part of the sealing member and overlies the axially inner end of the head on the body of the valve element. The sealing member has a flange which first extends generally radially outwardly from an annular root at the axially outer end of the main part of the sealing member and then turns axially inwardly to form an annular flange which, in relaxed condition, lies generally coaxial of and radially spaced from the annular body of the main part of the sealing member. Normal sealing between the sealing member and the valve seat takes place in the vicinity of the root of the flange. When engaging the valve seat, the flange yields to varying degrees, depending upon the pressure to which it is subjected.
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